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Kirsch, David Guy

Overview:

My clinical interests are the multi-modality care of patients with bone and soft tissue sarcomas and developing new sarcoma therapies. My laboratory interests include utilizing mouse models of cancer to study cancer and radiation biology in order to develop new cancer therapies in the pre-clinical setting.

Positions:

Barbara Levine University Professor

Radiation Oncology
School of Medicine

Professor of Radiation Oncology

Radiation Oncology
School of Medicine

Professor of Pharmacology and Cancer Biology

Pharmacology & Cancer Biology
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Affiliate of the Regeneration Next Initiative

Regeneration Next Initiative
School of Medicine

Education:

M.D. 2000

M.D. — Johns Hopkins University School of Medicine

Ph.D. 2000

Ph.D. — Johns Hopkins University School of Medicine

News:

Grants:

Advancing Cancer Therapy through Ground Breaking Research in Radiation Biology

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
January 04, 2016
End Date
December 31, 2022

The Duke Preclinical Research Resources for Quantitative Imaging Biomarkers

Administered By
Radiology
AwardedBy
National Institutes of Health
Role
Advisor
Start Date
September 30, 2017
End Date
August 31, 2022

Medical Scientist Training Program

Administered By
School of Medicine
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1997
End Date
June 30, 2022

Training Program in Developmental and Stem Cell Biology

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
May 01, 2001
End Date
April 30, 2022

Translational Research in Surgical Oncology

Administered By
Surgery, Surgical Sciences
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
January 01, 2002
End Date
August 31, 2021

Evaluation of kinase inhibitors

Administered By
Pharmacology & Cancer Biology
AwardedBy
XRAD THERAPEUTICS, INC.
Role
Co Investigator
Start Date
August 19, 2016
End Date
August 18, 2021

Awakening the dormant tumor: the role of the tumor microenvironment in breast cancer recurrence

Administered By
Pharmacology & Cancer Biology
AwardedBy
National Institutes of Health
Role
Co-Sponsor
Start Date
August 01, 2017
End Date
July 31, 2021

Codon bias imposes a targetable limitation on KRAS-driven therapeutic resistance

Administered By
Pharmacology & Cancer Biology
AwardedBy
National Institutes of Health
Role
Co-Sponsor
Start Date
July 01, 2017
End Date
June 30, 2021

Dissecting the role of the immune system in the radiation response of Kras-mutant tumors

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 2017
End Date
June 30, 2021

Using CRISPR/Cas9 to dissect the role of FUS-CHOP in tumor response to radiation therapy

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 2016
End Date
June 30, 2020

Pembroluzimab and Radiation Therapy to Improve Outcome in Localized High-Risk Sarcoma

Administered By
Radiation Oncology
AwardedBy
Association of American Cancer Institutes
Role
Principal Investigator
Start Date
May 01, 2017
End Date
February 29, 2020

Targeting the Hippo pathway in Ras-driven rhabdomyosarcoma

Administered By
Pediatrics, Hematology-Oncology
AwardedBy
V Foundation for Cancer Research
Role
Collaborator
Start Date
November 01, 2016
End Date
October 31, 2019

Investigating 1E10 Fc as a radiosensitizer in primary mouse sarcomas

Administered By
Radiation Oncology
AwardedBy
Eli Lilly and Company
Role
Principal Investigator
Start Date
September 22, 2017
End Date
September 21, 2019

Role of ErbB Receptor Signaling in Regulating Normal and Leukemic Stem Cell Fate

Administered By
Medicine, Hematological Malignancies
AwardedBy
National Institutes of Health
Role
Collaborator
Start Date
September 09, 2014
End Date
August 31, 2019

Dissecting mechanism(s) by which ionizing radiation promotes clonal expansion of premalignant cells in the thymus

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
September 15, 2016
End Date
August 31, 2018

Skeletal Muscle and Vascular Remodeling in Peripheral Artery Disease

Administered By
Medicine, Cardiology
AwardedBy
National Institutes of Health
Role
Collaborator
Start Date
September 01, 2015
End Date
August 31, 2018

Radiosensitization of brainstem gliomas by targeting ATM

Administered By
Radiation Oncology
AwardedBy
St. Baldrick's Foundation
Role
Principal Investigator
Start Date
July 01, 2017
End Date
June 30, 2018

Seahorse XFe96 Extracellular Flux Analyzer

Administered By
Pediatrics, Endocrinology
AwardedBy
North Carolina Biotechnology Center
Role
Major User
Start Date
June 07, 2017
End Date
June 06, 2018

Dissecting the Mechanisms of Immune Mediated Radiation Resistance in Sarcomas

Administered By
Radiation Oncology
AwardedBy
Sarcoma Foundation of America
Role
Principal Investigator
Start Date
June 01, 2017
End Date
May 31, 2018

An Activatable Nanoparticle Probe for Molecular Imaging of Protease Activity by Dual Energy CT

Administered By
School of Medicine
AwardedBy
National Institutes of Health
Role
Investigator
Start Date
June 01, 2015
End Date
May 31, 2018

Non-Canonical Responses to DNA damage in Drosophila Polyploid Cells

Administered By
Pharmacology & Cancer Biology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
March 01, 2015
End Date
February 28, 2018

Gertrude B Elion Award - Amy Wisdom

Administered By
Radiation Oncology
AwardedBy
Triangle Community Foundation
Role
Principal Investigator
Start Date
June 01, 2016
End Date
January 31, 2018

The role of MST1 in non-canonical Hippo signaling in rhabdomyosarcoma

Administered By
Pediatrics, Hematology-Oncology
AwardedBy
Alex's Lemonade Stand
Role
Collaborator
Start Date
January 15, 2015
End Date
January 14, 2018

Defining the role of miR-182 in HZE-induced tumorignesis

Administered By
Radiation Oncology
AwardedBy
National Aeronautics and Space Administration
Role
Principal Investigator
Start Date
January 06, 2014
End Date
January 05, 2018

Clinical Trials Umbrella - Scanned Beam

Administered By
Radiation Oncology
AwardedBy
Massachusetts General Hospital
Role
Co-Principal Investigator
Start Date
November 09, 2016
End Date
December 31, 2017

A novel therapeutic target for radiation-induced hematological malignancies: calcium calmodulin kinase kinase 2

Administered By
Medicine, Hematologic Malignancies and Cellular Therapy
AwardedBy
Department of Defense
Role
Investigator
Start Date
September 15, 2015
End Date
September 14, 2017

Dissecting the role of injury is sarcoma formation

Administered By
Pediatrics, Hematology-Oncology
AwardedBy
Sarcoma Alliance for Research Through Collaboration
Role
Mentor
Start Date
July 01, 2015
End Date
August 31, 2017

Dissecting the role of injury is sarcoma formation

Administered By
Pediatrics, Hematology-Oncology
AwardedBy
Sarcoma Alliance for Research Through Collaboration
Role
Mentor
Start Date
July 01, 2015
End Date
August 31, 2017

Mechanisms that Regulate Sarcoma Response to Immune Checkpoint Inhibition of PD-1

Administered By
Radiation Oncology
AwardedBy
Sarcoma Alliance for Research Through Collaboration
Role
Principal Investigator
Start Date
April 01, 2015
End Date
August 31, 2017

Training Grant in Radiation Biology

Administered By
Radiation Oncology
AwardedBy
Vanderbilt University
Role
Principal Investigator
Start Date
February 01, 2016
End Date
June 30, 2017

Testing current and developing novel therapies for NF1-mutant sarcomas in a genetically engineered mouse model

Administered By
Radiation Oncology
AwardedBy
Department of Defense
Role
Principal Investigator
Start Date
March 15, 2014
End Date
March 14, 2017

Janssen Research AGreement

Administered By
Radiation Oncology
AwardedBy
Janssen Research & Development, LLC
Role
Collaborator
Start Date
November 27, 2014
End Date
December 31, 2016

Skeletal Muscle and Vascular Remodeling in Peripheral Artery Disease

Administered By
Medicine, Cardiology
AwardedBy
National Institutes of Health
Role
Collaborator
Start Date
September 01, 2014
End Date
August 31, 2016

Muscle-Resident Stem Cells for Angiogenesis and Vascular Maturation in PAD

Administered By
Medicine, Cardiology
AwardedBy
National Institutes of Health
Role
Collaborator
Start Date
August 01, 2013
End Date
July 31, 2016

Intraoperative detection and ablation of microscopic residual cancer in the tumor bed

Administered By
Orthopaedics
AwardedBy
Lumicell Diagnostics
Role
Collaborator
Start Date
September 01, 2013
End Date
May 31, 2016

Cancer Biology Training Grant

Administered By
Pharmacology & Cancer Biology
AwardedBy
National Cancer Institute
Role
Mentor
Start Date
July 01, 1993
End Date
March 31, 2016

Independent Scientist Award for Radiation Research

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
February 03, 2011
End Date
January 31, 2016

Duke NSCOR: Lung Cancer Risk from HZE Ions

Administered By
Radiation Oncology
AwardedBy
National Aeronautics and Space Administration
Role
Principal Investigator
Start Date
January 01, 2011
End Date
January 31, 2016

Radiation Therapy: Dissecting the Role of Stromal Cells in Tumor Control

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 01, 2013
End Date
January 03, 2016

Defining the Cellular Target of Radiation Therapy

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
January 01, 2014
End Date
December 31, 2015

Evaluating GSK2126458 with radiation therapy in pre-clinical models

Administered By
Radiation Oncology
AwardedBy
GlaxoSmithKline
Role
Principal Investigator
Start Date
November 14, 2013
End Date
November 14, 2015

Clinical Oncology Research Career Development Program

Administered By
Surgery, Surgical Sciences
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
September 29, 2009
End Date
July 31, 2015

Modulation of Endothelial Cell Radiation Sensitivity and Lung Tumor Response to Radiation Therapy

Administered By
Radiation Oncology
AwardedBy
Rsna Research & Education Fund
Role
Principal Investigator
Start Date
July 01, 2014
End Date
June 30, 2015

Dissecting the roles of HIF-1a and HIF-2a in tumor response to radiation therapy

Administered By
School of Medicine
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 2013
End Date
April 30, 2015

Defining the cellular target of radiotherapy in primary mouse models of cancer

Administered By
School of Medicine
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
April 01, 2013
End Date
March 31, 2015

SARC Sarcoma SPORE - Developmental Research Program

Administered By
Radiation Oncology
AwardedBy
Sarcoma Alliance for Research Through Collaboration
Role
Principal Investigator
Start Date
April 01, 2013
End Date
March 31, 2015

Engineered imaging nanoparticles for real-time detection of cancer in the tumor bed

Administered By
Orthopaedics
AwardedBy
Lumicell Diagnostics
Role
Investigator
Start Date
September 01, 2013
End Date
January 31, 2015

Dissecting Mechanisms of Metastasis Through Comparative Systems Genetics

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 25, 2008
End Date
July 31, 2013

Mechanisms of Late Effects of Exposure to Radiation

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 01, 2008
End Date
July 31, 2013

A Fluorescence Histology System for In Vivo Breast Tumor Margin Assessment

Administered By
Biomedical Engineering
AwardedBy
National Institutes of Health
Role
Collaborator
Start Date
March 01, 2011
End Date
February 28, 2013

Small Animal PET / CT Molecular Imaging

Administered By
Radiology, Nuclear Medicine
AwardedBy
National Institutes of Health
Role
Major User
Start Date
April 01, 2011
End Date
March 31, 2012

Image-Guided Radiation Therapy and Radiosurgery for Small Animals

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 01, 2009
End Date
August 31, 2011

Intravital point-scanning confocal microscope

Administered By
Biomedical Engineering
AwardedBy
National Institutes of Health
Role
Major User
Start Date
May 06, 2010
End Date
May 05, 2011

Imaging Lung Cancer in Mice to Improve Radiation Therapy

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 03, 2005
End Date
July 31, 2010

Dissecting Mechanism of GI Syndrome to Restore Function after Radiation Exposure

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 01, 2007
End Date
February 28, 2010
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Publications:

NF1+/- Hematopoietic Cells Accelerate Malignant Peripheral Nerve Sheath Tumor Development without Altering Chemotherapy Response.

Haploinsufficiency in the tumor suppressor NF1 contributes to the pathobiology of neurofibromatosis type 1, but a related role has not been established in malignant peripheral nerve sheath tumors (MPNST) where NF1 mutations also occur. Patients with NF1-associated MPNST appear to have worse outcomes than patients with sporadic MPNST, but the mechanism underlying this correlation is not understood. To define the impact of stromal genetics on the biology of this malignancy, we developed unique mouse models that reflect the genetics of patient-associated MPNST. Specifically, we used adenovirus-Cre injections to generate MPNST in Nf1Flox/Flox; Ink4a/ArfFlox/Flox and Nf1Flox/-; Ink4a/ArfFlox/Flox paired littermate mice to model tumors from NF1-wild-type and NF1-associated patients, respectively. In these models, Nf1 haploinsufficiency in hematopoietic cells accelerated tumor onset and increased levels of tumor-infiltrating immune cells comprised of CD11b+ cells, monocytes, and mast cells. We observed that mast cells were also enriched in human NF1-associated MPNST. In a coclinical trial to examine how the tumor microenvironment influences the response to multiagent chemotherapy, we found that stromal Nf1 status had no effect. Taken together, our results clarify the role of the NF1-haploinsufficient tumor microenvironment in MPNST. Cancer Res; 77(16); 4486-97. ©2017 AACR.

Authors
Dodd, RD; Lee, C-L; Overton, T; Huang, W; Eward, WC; Luo, L; Ma, Y; Ingram, DR; Torres, KE; Cardona, DM; Lazar, AJ; Kirsch, DG
MLA Citation
Dodd, RD, Lee, C-L, Overton, T, Huang, W, Eward, WC, Luo, L, Ma, Y, Ingram, DR, Torres, KE, Cardona, DM, Lazar, AJ, and Kirsch, DG. "NF1+/- Hematopoietic Cells Accelerate Malignant Peripheral Nerve Sheath Tumor Development without Altering Chemotherapy Response." Cancer research 77.16 (August 2017): 4486-4497.
PMID
28646022
Source
epmc
Published In
Cancer Research
Volume
77
Issue
16
Publish Date
2017
Start Page
4486
End Page
4497
DOI
10.1158/0008-5472.can-16-2643

Generation and comparison of CRISPR-Cas9 and Cre-mediated genetically engineered mouse models of sarcoma.

Genetically engineered mouse models that employ site-specific recombinase technology are important tools for cancer research but can be costly and time-consuming. The CRISPR-Cas9 system has been adapted to generate autochthonous tumours in mice, but how these tumours compare to tumours generated by conventional recombinase technology remains to be fully explored. Here we use CRISPR-Cas9 to generate multiple subtypes of primary sarcomas efficiently in wild type and genetically engineered mice. These data demonstrate that CRISPR-Cas9 can be used to generate multiple subtypes of soft tissue sarcomas in mice. Primary sarcomas generated with CRISPR-Cas9 and Cre recombinase technology had similar histology, growth kinetics, copy number variation and mutational load as assessed by whole exome sequencing. These results show that sarcomas generated with CRISPR-Cas9 technology are similar to sarcomas generated with conventional modelling techniques and suggest that CRISPR-Cas9 can be used to more rapidly generate genotypically and phenotypically similar cancers.

Authors
Huang, J; Chen, M; Whitley, MJ; Kuo, H-C; Xu, ES; Walens, A; Mowery, YM; Van Mater, D; Eward, WC; Cardona, DM; Luo, L; Ma, Y; Lopez, OM; Nelson, CE; Robinson-Hamm, JN; Reddy, A; Dave, SS; Gersbach, CA; Dodd, RD; Kirsch, DG
MLA Citation
Huang, J, Chen, M, Whitley, MJ, Kuo, H-C, Xu, ES, Walens, A, Mowery, YM, Van Mater, D, Eward, WC, Cardona, DM, Luo, L, Ma, Y, Lopez, OM, Nelson, CE, Robinson-Hamm, JN, Reddy, A, Dave, SS, Gersbach, CA, Dodd, RD, and Kirsch, DG. "Generation and comparison of CRISPR-Cas9 and Cre-mediated genetically engineered mouse models of sarcoma." Nature communications 8 (July 10, 2017): 15999-.
PMID
28691711
Source
epmc
Published In
Nature Communications
Volume
8
Publish Date
2017
Start Page
15999
DOI
10.1038/ncomms15999

Genetically engineered mouse models for studying radiation biology

Authors
Castle, KD; Chen, M; Wisdom, AJ; Kirsch, DG
MLA Citation
Castle, KD, Chen, M, Wisdom, AJ, and Kirsch, DG. "Genetically engineered mouse models for studying radiation biology." Translational Cancer Research 6.S5 (July 2017): S900-S913.
Source
crossref
Published In
Translational cancer research
Volume
6
Issue
S5
Publish Date
2017
Start Page
S900
End Page
S913
DOI
10.21037/tcr.2017.06.19

Characterization of novel preclinical dose distributions for micro irradiator

Authors
Kodra, J; Miles, D; Yoon, SW; Kirsch, DG; Oldham, M
MLA Citation
Kodra, J, Miles, D, Yoon, SW, Kirsch, DG, and Oldham, M. "Characterization of novel preclinical dose distributions for micro irradiator." May 2017.
Source
crossref
Published In
Journal of Physics
Volume
847
Publish Date
2017
Start Page
012054
End Page
012054
DOI
10.1088/1742-6596/847/1/012054

Treatment planning and 3D dose verification of whole brain radiation therapy with hippocampal avoidance in rats

Authors
Yoon, SW; Miles, D; Cramer, C; Reinsvold, M; Kirsch, D; Oldham, M
MLA Citation
Yoon, SW, Miles, D, Cramer, C, Reinsvold, M, Kirsch, D, and Oldham, M. "Treatment planning and 3D dose verification of whole brain radiation therapy with hippocampal avoidance in rats." May 2017.
Source
crossref
Published In
Journal of Physics
Volume
847
Publish Date
2017
Start Page
012004
End Page
012004
DOI
10.1088/1742-6596/847/1/012004

p53 Regulates Progenitor Cell Quiescence and Differentiation in the Airway.

Mechanisms that regulate progenitor cell quiescence and differentiation in slowly replacing tissues are not fully understood. Here, we demonstrate that the tumor suppressor p53 regulates both proliferation and differentiation of progenitors in the airway epithelium. p53 loss decreased ciliated cell differentiation and increased the self-renewal and proliferative capacity of club progenitors, increasing epithelial cell density. p53-deficient progenitors generated a pseudostratified epithelium containing basal-like cells in vitro and putative bronchioalveolar stem cells in vivo. Conversely, an additional copy of p53 increased quiescence and ciliated cell differentiation, highlighting the importance of tight regulation of p53 levels. Using single-cell RNA sequencing, we found that loss of p53 altered the molecular phenotype of progenitors and differentially modulated cell-cycle regulatory genes. Together, these findings reveal that p53 is an essential regulator of progenitor cell behavior, which shapes our understanding of stem cell quiescence during homeostasis and in cancer development.

Authors
McConnell, AM; Yao, C; Yeckes, AR; Wang, Y; Selvaggio, AS; Tang, J; Kirsch, DG; Stripp, BR
MLA Citation
McConnell, AM, Yao, C, Yeckes, AR, Wang, Y, Selvaggio, AS, Tang, J, Kirsch, DG, and Stripp, BR. "p53 Regulates Progenitor Cell Quiescence and Differentiation in the Airway." Cell reports 17.9 (November 2016): 2173-2182.
PMID
27880895
Source
epmc
Published In
Cell Reports
Volume
17
Issue
9
Publish Date
2016
Start Page
2173
End Page
2182
DOI
10.1016/j.celrep.2016.11.007

Radiation Therapy for Soft Tissue Sarcoma: Indications and Controversies for Neoadjuvant Therapy, Adjuvant Therapy, Intraoperative Radiation Therapy, and Brachytherapy.

Soft tissue sarcomas are rare mesenchymal cancers that pose a treatment challenge. Although small superficial soft tissue sarcomas can be managed by surgery alone, adjuvant radiotherapy in addition to limb-sparing surgery substantially increases local control of extremity sarcomas. Compared with postoperative radiotherapy, preoperative radiotherapy doubles the risk of a wound complication, but decreases the risk for late effects, which are generally irreversible. For retroperitoneal sarcomas, intraoperative radiotherapy can be used to safely escalate the radiation dose to the tumor bed. Patients with newly diagnosed sarcoma should be evaluated before surgery by a multidisciplinary team that includes a radiation oncologist.

Authors
Larrier, NA; Czito, BG; Kirsch, DG
MLA Citation
Larrier, NA, Czito, BG, and Kirsch, DG. "Radiation Therapy for Soft Tissue Sarcoma: Indications and Controversies for Neoadjuvant Therapy, Adjuvant Therapy, Intraoperative Radiation Therapy, and Brachytherapy." Surgical oncology clinics of North America 25.4 (October 2016): 841-860. (Review)
PMID
27591502
Source
epmc
Published In
Surgical Oncology Clinics of North America
Volume
25
Issue
4
Publish Date
2016
Start Page
841
End Page
860
DOI
10.1016/j.soc.2016.05.012

Distal airway epithelial progenitor cells are radiosensitive to High-LET radiation.

Exposure to high-linear energy transfer (LET) radiation occurs in a variety of situations, including charged particle radiotherapy, radiological accidents, and space travel. However, the extent of normal tissue injury in the lungs following high-LET radiation exposure is unknown. Here we show that exposure to high-LET radiation led to a prolonged loss of in vitro colony forming ability by airway epithelial progenitor cells. Furthermore, exposure to high-LET radiation induced clonal expansion of a subset of progenitor cells in the distal airway epithelium. Clonal expansion following high-LET radiation exposure was correlated with elevated progenitor cell apoptosis, persistent γ-H2AX foci, and defects in mitotic progression of distal airway progenitors. We discovered that the effects of high-LET radiation exposure on progenitor cells occur in a p53-dependent manner. These data show that high-LET radiation depletes the distal airway progenitor pool by inducing cell death and loss of progenitor function, leading to clonal expansion. Importantly, high-LET radiation induces greater long-term damage to normal lung tissue than the relative equivalent dose of low-LET γ-rays, which has implications in therapeutic development and risk assessment.

Authors
McConnell, AM; Konda, B; Kirsch, DG; Stripp, BR
MLA Citation
McConnell, AM, Konda, B, Kirsch, DG, and Stripp, BR. "Distal airway epithelial progenitor cells are radiosensitive to High-LET radiation." Scientific Reports 6 (September 23, 2016): 33455-.
PMID
27659946
Source
epmc
Published In
Scientific Reports
Volume
6
Publish Date
2016
Start Page
33455
DOI
10.1038/srep33455

Algorithms for differentiating between images of heterogeneous tissue across fluorescence microscopes.

Fluorescence microscopy can be used to acquire real-time images of tissue morphology and with appropriate algorithms can rapidly quantify features associated with disease. The objective of this study was to assess the ability of various segmentation algorithms to isolate fluorescent positive features (FPFs) in heterogeneous images and identify an approach that can be used across multiple fluorescence microscopes with minimal tuning between systems. Specifically, we show a variety of image segmentation algorithms applied to images of stained tumor and muscle tissue acquired with 3 different fluorescence microscopes. Results indicate that a technique called maximally stable extremal regions followed by thresholding (MSER + Binary) yielded the greatest contrast in FPF density between tumor and muscle images across multiple microscopy systems.

Authors
Chitalia, R; Mueller, J; Fu, HL; Whitley, MJ; Kirsch, DG; Brown, JQ; Willett, R; Ramanujam, N
MLA Citation
Chitalia, R, Mueller, J, Fu, HL, Whitley, MJ, Kirsch, DG, Brown, JQ, Willett, R, and Ramanujam, N. "Algorithms for differentiating between images of heterogeneous tissue across fluorescence microscopes." Biomedical optics express 7.9 (September 2016): 3412-3424.
PMID
27699108
Source
epmc
Published In
Biomedical Optics Express
Volume
7
Issue
9
Publish Date
2016
Start Page
3412
End Page
3424
DOI
10.1364/boe.7.003412

A Novel Imaging System Distinguishes Neoplastic from Normal Tissue During Resection of Soft Tissue Sarcomas and Mast Cell Tumors in Dogs.

To assess the ability of a novel imaging system designed for intraoperative detection of residual cancer in tumor beds to distinguish neoplastic from normal tissue in dogs undergoing resection of soft tissue sarcoma (STS) and mast cell tumor (MCT).Non-randomized prospective clinical trial.12 dogs with STS and 7 dogs with MCT.A fluorescent imaging agent that is activated by proteases in vivo was administered to the dogs 4-6 or 24-26 hours before tumor resection. During surgery, a handheld imaging device was used to measure fluorescence intensity within the cancerous portion of the resected specimen and determine an intensity threshold for subsequent identification of cancer. Selected areas within the resected specimen and tumor bed were then imaged, and biopsies (n=101) were obtained from areas that did or did not have a fluorescence intensity exceeding the threshold. Results of intraoperative fluorescence and histology were compared.The imaging system correctly distinguished cancer from normal tissue in 93/101 biopsies (92%). Using histology as the reference, the sensitivity and specificity of the imaging system for identification of cancer in biopsies were 92% and 92%, respectively. There were 10/19 (53%) dogs which exhibited transient facial erythema soon after injection of the imaging agent which responded to but was not consistently prevented by intravenous diphenhydramine.A fluorescence-based imaging system designed for intraoperative use can distinguish canine soft tissue sarcoma (STS) and mast cell tumor (MCT) tissue from normal tissue with a high degree of accuracy. The system has potential to assist surgeons in assessing the adequacy of tumor resections during surgery, potentially reducing the risk of local tumor recurrence. Although responsive to antihistamines, the risk of hypersensitivity needs to be considered in light of the potential benefits of this imaging system in dogs.

Authors
Bartholf DeWitt, S; Eward, WC; Eward, CA; Lazarides, AL; Whitley, MJ; Ferrer, JM; Brigman, BE; Kirsch, DG; Berg, J
MLA Citation
Bartholf DeWitt, S, Eward, WC, Eward, CA, Lazarides, AL, Whitley, MJ, Ferrer, JM, Brigman, BE, Kirsch, DG, and Berg, J. "A Novel Imaging System Distinguishes Neoplastic from Normal Tissue During Resection of Soft Tissue Sarcomas and Mast Cell Tumors in Dogs." Veterinary surgery : VS 45.6 (August 2016): 715-722.
PMID
27281113
Source
epmc
Published In
Veterinary Surgery
Volume
45
Issue
6
Publish Date
2016
Start Page
715
End Page
722
DOI
10.1111/vsu.12487

Mesenchymal Tumors Can Derive from Ng2/Cspg4-Expressing Pericytes with β-Catenin Modulating the Neoplastic Phenotype.

The cell of origin for most mesenchymal tumors is unclear. One cell type that contributes to this lineages is the pericyte, a cell expressing Ng2/Cspg4. Using lineage tracing, we demonstrated that bone and soft tissue sarcomas driven by the deletion of the Trp53 tumor suppressor, or desmoid tumors driven by a mutation in Apc, can derive from cells expressing Ng2/Cspg4. Deletion of the Trp53 tumor suppressor gene in these cells resulted in the bone and soft tissue sarcomas that closely resemble human sarcomas, while stabilizing β-catenin in this same cell type caused desmoid tumors. Comparing expression between Ng2/Cspg4-expressing pericytes lacking Trp53 and sarcomas that arose from deletion of Trp53 showed inhibition of β-catenin signaling in the sarcomas. Activation of β-catenin inhibited the formation and growth of sarcomas. Thus, pericytes can be a cell of origin for mesenchymal tumors, and β-catenin dysregulation plays an important role in the neoplastic phenotype.

Authors
Sato, S; Tang, YJ; Wei, Q; Hirata, M; Weng, A; Han, I; Okawa, A; Takeda, S; Whetstone, H; Nadesan, P; Kirsch, DG; Wunder, JS; Alman, BA
MLA Citation
Sato, S, Tang, YJ, Wei, Q, Hirata, M, Weng, A, Han, I, Okawa, A, Takeda, S, Whetstone, H, Nadesan, P, Kirsch, DG, Wunder, JS, and Alman, BA. "Mesenchymal Tumors Can Derive from Ng2/Cspg4-Expressing Pericytes with β-Catenin Modulating the Neoplastic Phenotype." Cell reports 16.4 (July 13, 2016): 917-927.
PMID
27425618
Source
epmc
Published In
Cell Reports
Volume
16
Issue
4
Publish Date
2016
Start Page
917
End Page
927
DOI
10.1016/j.celrep.2016.06.058

Externally applied high-dose-rate brachytherapy for deeply invasive cutaneous squamous cell carcinoma in an older patient.

Authors
Whitley, MJ; Cardones, AR; Craciunescu, OI; Kirsch, DG
MLA Citation
Whitley, MJ, Cardones, AR, Craciunescu, OI, and Kirsch, DG. "Externally applied high-dose-rate brachytherapy for deeply invasive cutaneous squamous cell carcinoma in an older patient." Practical radiation oncology 6.4 (July 2016): e141-e144.
PMID
26746817
Source
epmc
Published In
Practical Radiation Oncology
Volume
6
Issue
4
Publish Date
2016
Start Page
e141
End Page
e144
DOI
10.1016/j.prro.2015.11.008

Margin reduction from image guided radiation therapy for soft tissue sarcoma: Secondary analysis of Radiation Therapy Oncology Group 0630 results.

Six imaging modalities were used in Radiation Therapy Oncology Group (RTOG) 0630, a study of image guided radiation therapy (IGRT) for primary soft tissue sarcomas of the extremity. We analyzed all daily patient-repositioning data collected in this trial to determine the impact of daily IGRT on clinical target volume-to-planning target volume (CTV-to-PTV) margin.Daily repositioning data, including shifts in right-left (RL), superior-inferior (SI), and anterior-posterior (AP) directions and rotations for 98 patients enrolled in RTOG 0630 from 18 institutions were analyzed. Patients were repositioned daily on the basis of bone anatomy by using pretreatment images, including kilovoltage orthogonal images (KVorth), megavoltage orthogonal images (MVorth), KV fan-beam computed tomography (KVCT), KV cone beam CT (KVCB), MV fan-beam CT (MVCT), and MV cone beam CT (MVCB). Means and standard deviations (SDs) for each shift and rotation were calculated for each patient and for each IGRT modality. The Student's t tests and F-tests were performed to analyze the differences in the means and SDs. Necessary CTV-to-PTV margins were estimated.The repositioning shifts and day-to-day variations were large and generally similar for the 6 imaging modalities. Of the 2 most commonly used modalities, MVCT and KVorth, there were no statistically significant differences in the shifts and rotations (P = .15 and .59 for the RL and SI shifts, respectively; and P = .22 for rotation), except for shifts in AP direction (P = .002). The estimated CTV-to-PTV margins in the RL, SI, and AP directions would be 13.0, 10.4, and 11.7 mm from MVCT data, respectively, and 13.1, 8.6, and 10.8 mm from KVorth data, respectively, indicating that margins substantially larger than 5 mm used with daily IGRT would be required in the absence of IGRT.The observed large daily repositioning errors and the large variations among institutions imply that daily IGRT is necessary for this tumor site, particularly in multi-institutional trials. Otherwise, a CTV-to-PTV margin of 1.5 cm is required to account for daily setup variations.

Authors
Li, XA; Chen, X; Zhang, Q; Kirsch, DG; Petersen, I; DeLaney, TF; Freeman, CR; Trotti, A; Hitchcock, Y; Bedi, M; Haddock, M; Salerno, K; Dundas, G; Wang, D
MLA Citation
Li, XA, Chen, X, Zhang, Q, Kirsch, DG, Petersen, I, DeLaney, TF, Freeman, CR, Trotti, A, Hitchcock, Y, Bedi, M, Haddock, M, Salerno, K, Dundas, G, and Wang, D. "Margin reduction from image guided radiation therapy for soft tissue sarcoma: Secondary analysis of Radiation Therapy Oncology Group 0630 results." Practical radiation oncology 6.4 (July 2016): e135-e140.
PMID
26852173
Source
epmc
Published In
Practical Radiation Oncology
Volume
6
Issue
4
Publish Date
2016
Start Page
e135
End Page
e140
DOI
10.1016/j.prro.2015.11.012

Improving the Predictive Value of Preclinical Studies in Support of Radiotherapy Clinical Trials.

There is an urgent need to improve reproducibility and translatability of preclinical data to fully exploit opportunities for molecular therapeutics involving radiation and radiochemotherapy. For in vitro research, the clonogenic assay remains the current state-of-the-art of preclinical assays, whereas newer moderate and high-throughput assays offer the potential for rapid initial screening. Studies of radiation response modification by molecularly targeted agents can be improved using more physiologic 3D culture models. Elucidating effects on the cancer stem cells (CSC, and CSC-like) and developing biomarkers for defining targets and measuring responses are also important. In vivo studies are necessary to confirm in vitro findings, further define mechanism of action, and address immunomodulation and treatment-induced modification of the microenvironment. Newer in vivo models include genetically engineered and patient-derived xenograft mouse models and spontaneously occurring cancers in domesticated animals. Selection of appropriate endpoints is important for in vivo studies; for example, regrowth delay measures bulk tumor killing, whereas local tumor control assesses effects on CSCs. The reliability of individual assays requires standardization of procedures and cross-laboratory validation. Radiation modifiers must be tested as part of clinical standard of care, which includes radiochemotherapy for most tumors. Radiation models are compatible with but also differ from those used for drug screening. Furthermore, the mechanism of a drug as a chemotherapeutic agent may be different from its interaction with radiation and/or radiochemotherapy. This provides an opportunity to expand the use of molecular-targeted agents. Clin Cancer Res; 22(13); 3138-47. ©2016 AACR.

Authors
Coleman, CN; Higgins, GS; Brown, JM; Baumann, M; Kirsch, DG; Willers, H; Prasanna, PGS; Dewhirst, MW; Bernhard, EJ; Ahmed, MM
MLA Citation
Coleman, CN, Higgins, GS, Brown, JM, Baumann, M, Kirsch, DG, Willers, H, Prasanna, PGS, Dewhirst, MW, Bernhard, EJ, and Ahmed, MM. "Improving the Predictive Value of Preclinical Studies in Support of Radiotherapy Clinical Trials." Clinical cancer research : an official journal of the American Association for Cancer Research 22.13 (July 2016): 3138-3147. (Review)
PMID
27154913
Source
epmc
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
22
Issue
13
Publish Date
2016
Start Page
3138
End Page
3147
DOI
10.1158/1078-0432.ccr-16-0069

Preoperative or postoperative radiotherapy versus surgery alone for retroperitoneal sarcoma: a case-control, propensity score-matched analysis of a nationwide clinical oncology database.

Recruitment into clinical trials for retroperitoneal sarcoma has been challenging, resulting in termination of the only randomised multicentre trial in the USA investigating perioperative radiotherapy. Nonetheless, use of radiotherapy for retroperitoneal sarcoma has increased over the past decade, substantiated primarily by its established role in extremity sarcoma. In this study, we used a nationwide clinical oncology database to separately compare overall survival for patients with retroperitoneal sarcoma who had surgery and preoperative radiotherapy or surgery and postoperative radiotherapy versus surgery alone.We did two case-control, propensity score-matched analyses of the National Cancer Data Base, which included adult patients with retroperitoneal sarcoma who were diagnosed from 2003 to 2011. Patients were included if they had localised, primary retroperitoneal sarcoma. Patients were classified into three groups based on use of radiotherapy: preoperative radiotherapy, postoperative radiotherapy, and no radiotherapy (surgery alone). Patients were excluded if they received both preoperative radiotherapy and postoperative radiotherapy, or if they received intraoperative radiotherapy. Parallel propensity score-matched datasets were created for patients who received preoperative radiotherapy versus those who received no radiotherapy and for patients who received postoperative therapy versus those who received no radiotherapy. Propensity scores were calculated with logistic regression, with multiple imputation and backwards elimination, with a significance level to stay of 0·05. Matching was done with a nearest-neighbour algorithm and matched 1:2 for the preoperative radiotherapy dataset and 1:1 for the postoperative radiotherapy dataset. The primary objective of interest was overall survival for patients who received preoperative radiotherapy or postoperative radiotherapy compared with those who received no radiotherapy within the propensity score-matched datasets.9068 patients were included in this analysis: 563 in the preoperative radiotherapy group, 2215 in the postoperative radiotherapy group, and 6290 in the no radiotherapy group. Matching resulted in two comparison groups (preoperative radiotherapy vs no radiotherapy, and postoperative radiotherapy vs no radiotherapy) with negligible differences in all demographic, clinicopathological, and treatment-level variables. In the matched case-control analysis for preoperative radiotherapy median follow-up time was 42 months (IQR 27-70) for the preoperative radiotherapy group versus 43 months (25-64) for the no radiotherapy group; median overall survival was 110 months (95% CI 75-not estimable) versus 66 months (61-76), respectively. In the matched case-control analysis for postoperative radiotherapy median follow-up time was 54 months (IQR 32-79) for patients in the postoperative radiotherapy group and 47 months (26-72) for patients in the no radiotherapy group; median overall survival was 89 months (95% CI 79-100) versus 64 months (59-69), respectively. Both preoperative radiotherapy (HR 0·70, 95% CI 0·59-0·82; p<0·0001) and postoperative radiotherapy (HR 0·78, 0·71-0·85; p<0·0001) were significantly associated with improved overall survival compared with surgery alone.To the best of our knowledge, this is the largest study to date of the effect of radiotherapy on overall survival in patients with retroperitoneal sarcoma. Radiotherapy was associated with improved overall survival compared with surgery alone when delivered as either preoperative radiotherapy or postoperative radiotherapy. Together with the results from the ongoing randomised EORTC trial (62092-22092; NCT01344018) investigating preoperative radiotherapy for retroperitoneal sarcoma pending, these data might provide additional support for the increasing use of radiotherapy for patients with retroperitoneal sarcoma undergoing surgical resection.Department of Surgery, Duke University School of Medicine.

Authors
Nussbaum, DP; Rushing, CN; Lane, WO; Cardona, DM; Kirsch, DG; Peterson, BL; Blazer, DG
MLA Citation
Nussbaum, DP, Rushing, CN, Lane, WO, Cardona, DM, Kirsch, DG, Peterson, BL, and Blazer, DG. "Preoperative or postoperative radiotherapy versus surgery alone for retroperitoneal sarcoma: a case-control, propensity score-matched analysis of a nationwide clinical oncology database." The Lancet. Oncology 17.7 (July 2016): 966-975.
PMID
27210906
Source
epmc
Published In
The Lancet Oncology
Volume
17
Issue
7
Publish Date
2016
Start Page
966
End Page
975
DOI
10.1016/s1470-2045(16)30050-x

Opportunities for Radiosensitization in the Stereotactic Body Radiation Therapy (SBRT) Era.

Stereotactic body radiation therapy (SBRT) utilizing a small number of high-dose radiation therapy fractions continues to expand in clinical application. Although many approaches have been proposed to radiosensitize tumors with conventional fractionation, how these radiosensitizers will translate to SBRT remains largely unknown. Here, we review our current understanding of how SBRT eradicates tumors, including the potential contributions of endothelial cell death and immune system activation. In addition, we identify several new opportunities for radiosensitization generated by the move toward high dose per fraction radiation therapy.

Authors
Moding, EJ; Mowery, YM; Kirsch, DG
MLA Citation
Moding, EJ, Mowery, YM, and Kirsch, DG. "Opportunities for Radiosensitization in the Stereotactic Body Radiation Therapy (SBRT) Era." Cancer journal (Sudbury, Mass.) 22.4 (July 2016): 267-273. (Review)
PMID
27441746
Source
epmc
Published In
Cancer Journal
Volume
22
Issue
4
Publish Date
2016
Start Page
267
End Page
273
DOI
10.1097/ppo.0000000000000203

Application of single-cell RNA sequencing in optimizing a combinatorial therapeutic strategy in metastatic renal cell carcinoma.

Intratumoral heterogeneity hampers the success of marker-based anticancer treatment because the targeted therapy may eliminate a specific subpopulation of tumor cells while leaving others unharmed. Accordingly, a rational strategy minimizing survival of the drug-resistant subpopulation is essential to achieve long-term therapeutic efficacy.Using single-cell RNA sequencing (RNA-seq), we examine the intratumoral heterogeneity of a pair of primary renal cell carcinoma and its lung metastasis. Activation of drug target pathways demonstrates considerable variability between the primary and metastatic sites, as well as among individual cancer cells within each site. Based on the prediction of multiple drug target pathway activation, we derive a combinatorial regimen co-targeting two mutually exclusive pathways for the metastatic cancer cells. This combinatorial strategy shows significant increase in the treatment efficacy over monotherapy in the experimental validation using patient-derived xenograft platforms in vitro and in vivo.Our findings demonstrate the investigational application of single-cell RNA-seq in the design of an anticancer regimen. The approach may overcome intratumoral heterogeneity which hampers the success of precision medicine.

Authors
Kim, K-T; Lee, HW; Lee, H-O; Song, HJ; Jeong, DE; Shin, S; Kim, H; Shin, Y; Nam, D-H; Jeong, BC; Kirsch, DG; Joo, KM; Park, W-Y
MLA Citation
Kim, K-T, Lee, HW, Lee, H-O, Song, HJ, Jeong, DE, Shin, S, Kim, H, Shin, Y, Nam, D-H, Jeong, BC, Kirsch, DG, Joo, KM, and Park, W-Y. "Application of single-cell RNA sequencing in optimizing a combinatorial therapeutic strategy in metastatic renal cell carcinoma." Genome biology 17 (April 29, 2016): 80-.
PMID
27139883
Source
epmc
Published In
Genome Biology: biology for the post-genomic era
Volume
17
Publish Date
2016
Start Page
80
DOI
10.1186/s13059-016-0945-9

MicroRNA-182 drives metastasis of primary sarcomas by targeting multiple genes

Authors
Sachdeva, M; Mito, JK; Lee, C-L; Zhang, M; Li, Z; Dodd, RD; Cason, D; Luo, L; Ma, Y; Van Mater, D; Gladdy, R; Lev, DC; Cardona, DM; Kirsch, DG
MLA Citation
Sachdeva, M, Mito, JK, Lee, C-L, Zhang, M, Li, Z, Dodd, RD, Cason, D, Luo, L, Ma, Y, Van Mater, D, Gladdy, R, Lev, DC, Cardona, DM, and Kirsch, DG. "MicroRNA-182 drives metastasis of primary sarcomas by targeting multiple genes." Journal of Clinical Investigation 126.4 (April 1, 2016): 1606-1606.
Source
crossref
Published In
Journal of Clinical Investigation
Volume
126
Issue
4
Publish Date
2016
Start Page
1606
End Page
1606
DOI
10.1172/JCI86573

Myogenic transcription factors regulate pro-metastatic miR-182.

Approximately 30% of patients with soft-tissue sarcoma die from pulmonary metastases. The mechanisms that drive sarcoma metastasis are not well understood. Recently, we identified miR-182 as a driver of sarcoma metastasis in a primary mouse model of soft-tissue sarcoma. We also observed elevated miR-182 in a subset of primary human sarcomas that metastasized to the lungs. Here, we show that myogenic differentiation factors regulate miR-182 levels to contribute to metastasis in mouse models. We find that MyoD directly binds the miR-182 promoter to increase miR-182 expression. Furthermore, mechanistic studies revealed that Pax7 can promote sarcoma metastasis in vivo through MyoD-dependent regulation of pro-metastatic miR-182. Taken together, these results suggest that sarcoma metastasis can be partially controlled through Pax7/MyoD-dependent activation of miR-182 and provide insight into the role that myogenic transcription factors have in sarcoma progression.

Authors
Dodd, RD; Sachdeva, M; Mito, JK; Eward, WC; Brigman, BE; Ma, Y; Dodd, L; Kim, Y; Lev, D; Kirsch, DG
MLA Citation
Dodd, RD, Sachdeva, M, Mito, JK, Eward, WC, Brigman, BE, Ma, Y, Dodd, L, Kim, Y, Lev, D, and Kirsch, DG. "Myogenic transcription factors regulate pro-metastatic miR-182." Oncogene 35.14 (April 2016): 1868-1875.
PMID
26234681
Source
epmc
Published In
Oncogene: Including Oncogene Reviews
Volume
35
Issue
14
Publish Date
2016
Start Page
1868
End Page
1875
DOI
10.1038/onc.2015.252

Structured Illumination Microscopy and a Quantitative Image Analysis for the Detection of Positive Margins in a Pre-Clinical Genetically Engineered Mouse Model of Sarcoma.

Intraoperative assessment of surgical margins is critical to ensuring residual tumor does not remain in a patient. Previously, we developed a fluorescence structured illumination microscope (SIM) system with a single-shot field of view (FOV) of 2.1 × 1.6 mm (3.4 mm2) and sub-cellular resolution (4.4 μm). The goal of this study was to test the utility of this technology for the detection of residual disease in a genetically engineered mouse model of sarcoma. Primary soft tissue sarcomas were generated in the hindlimb and after the tumor was surgically removed, the relevant margin was stained with acridine orange (AO), a vital stain that brightly stains cell nuclei and fibrous tissues. The tissues were imaged with the SIM system with the primary goal of visualizing fluorescent features from tumor nuclei. Given the heterogeneity of the background tissue (presence of adipose tissue and muscle), an algorithm known as maximally stable extremal regions (MSER) was optimized and applied to the images to specifically segment nuclear features. A logistic regression model was used to classify a tissue site as positive or negative by calculating area fraction and shape of the segmented features that were present and the resulting receiver operator curve (ROC) was generated by varying the probability threshold. Based on the ROC curves, the model was able to classify tumor and normal tissue with 77% sensitivity and 81% specificity (Youden's index). For an unbiased measure of the model performance, it was applied to a separate validation dataset that resulted in 73% sensitivity and 80% specificity. When this approach was applied to representative whole margins, for a tumor probability threshold of 50%, only 1.2% of all regions from the negative margin exceeded this threshold, while over 14.8% of all regions from the positive margin exceeded this threshold.

Authors
Fu, HL; Mueller, JL; Whitley, MJ; Cardona, DM; Willett, RM; Kirsch, DG; Brown, JQ; Ramanujam, N
MLA Citation
Fu, HL, Mueller, JL, Whitley, MJ, Cardona, DM, Willett, RM, Kirsch, DG, Brown, JQ, and Ramanujam, N. "Structured Illumination Microscopy and a Quantitative Image Analysis for the Detection of Positive Margins in a Pre-Clinical Genetically Engineered Mouse Model of Sarcoma." (January 22, 2016).
Website
http://hdl.handle.net/10161/10892
PMID
26799613
Source
epmc
Publish Date
2016
DOI
10.1371/journal.pone.0147006

A dual energy CT study on vascular effects of gold nanoparticles in radiation therapy

© 2016 SPIE. Gold nanoparticles (AuNPs) are emerging as promising agents for both cancer therapy and CT imaging. AuNPs are delivered to tumors via the enhanced permeability and retention effect and they preferentially accumulate in close proximity to the tumor blood vessels. AuNPs produce low-energy, short-range photoelectrons during external beam radiation therapy (RT), boosting dose. This work is focused on understanding how tumor vascular permeability is influenced by AuNP-augmented radiation therapy (RT), and how this knowledge can potentially improve the delivery of additional nanoparticle-based chemotherapeutics. We use dual energy (DE) CT to detect accumulation of AuNPs and increased vascular permeability to liposomal iodine (i.e. a surrogate for chemotherapeutics with liposome encapsulation) following RT. We used sarcoma tumors generated in LSL-Kras G12D ; p53 FL/FL conditional mutant mice. A total of n=37 mice were used in this study. The treated mice were injected with 20 mg AuNP (0.1 ml/25 g mouse) 24 hours before delivery of 5 Gy RT (n=5), 10 Gy RT (n=3) or 20 Gy RT (n=6). The control mice received no AuNP injection and either no RT (n=6), 5 Gy RT (n=3), 10 Gy RT (n=3), 20 Gy RT (n=1 1) . Twenty four hours post-RT, the mice were injected with liposomal iodine (0.3 ml/25 mouse) and imaged with DE-CT three days later. The results suggest that independent of any AuNP usage, RT levels of 10 Gy and 20 Gy increase the permeability of tumor vasculature to liposomal iodine and that the increase in permeability is dose-dependent. We found that the effect of RT on vasculature may already be at its maximum response i.e. saturated at 20 Gy, and therefore the addition of AuNPs had almost no added benefit. Similarly, at 5 Gy RT, our data suggests that there was no effect of AuNP augmentation on tumor vascular permeability. However, b y using AuNPs with 10 Gy RT, we observed an increase in the vascular permeability, however this is not yet statistically significant due to the small number of mice in these groups. Such an approach can be used together with a liposomal drug delivery system to increase specific tumor delivery of chemotherapeutics. Our method has the potential to significantly improve tumor therapy and reduce the side effects from both RT and chemotherapy.

Authors
Ashton, JR; Hoye, J; Deland, K; Whitley, M; Qi, Y; Moding, E; Kirsch, DG; West, J; Badea, CT
MLA Citation
Ashton, JR, Hoye, J, Deland, K, Whitley, M, Qi, Y, Moding, E, Kirsch, DG, West, J, and Badea, CT. "A dual energy CT study on vascular effects of gold nanoparticles in radiation therapy." January 1, 2016.
Source
scopus
Published In
Proceedings of SPIE
Volume
9788
Publish Date
2016
DOI
10.1117/12.2217012

A mouse-human phase 1 co-clinical trial of a protease-activated fluorescent probe for imaging cancer.

Local recurrence is a common cause of treatment failure for patients with solid tumors. Intraoperative detection of microscopic residual cancer in the tumor bed could be used to decrease the risk of a positive surgical margin, reduce rates of reexcision, and tailor adjuvant therapy. We used a protease-activated fluorescent imaging probe, LUM015, to detect cancer in vivo in a mouse model of soft tissue sarcoma (STS) and ex vivo in a first-in-human phase 1 clinical trial. In mice, intravenous injection of LUM015 labeled tumor cells, and residual fluorescence within the tumor bed predicted local recurrence. In 15 patients with STS or breast cancer, intravenous injection of LUM015 before surgery was well tolerated. Imaging of resected human tissues showed that fluorescence from tumor was significantly higher than fluorescence from normal tissues. LUM015 biodistribution, pharmacokinetic profiles, and metabolism were similar in mouse and human subjects. Tissue concentrations of LUM015 and its metabolites, including fluorescently labeled lysine, demonstrated that LUM015 is selectively distributed to tumors where it is activated by proteases. Experiments in mice with a constitutively active PEGylated fluorescent imaging probe support a model where tumor-selective probe distribution is a determinant of increased fluorescence in cancer. These co-clinical studies suggest that the tumor specificity of protease-activated imaging probes, such as LUM015, is dependent on both biodistribution and enzyme activity. Our first-in-human data support future clinical trials of LUM015 and other protease-sensitive probes.

Authors
Whitley, MJ; Cardona, DM; Lazarides, AL; Spasojevic, I; Ferrer, JM; Cahill, J; Lee, C-L; Snuderl, M; Blazer, DG; Hwang, ES; Greenup, RA; Mosca, PJ; Mito, JK; Cuneo, KC; Larrier, NA; O'Reilly, EK; Riedel, RF; Eward, WC; Strasfeld, DB; Fukumura, D; Jain, RK; Lee, WD; Griffith, LG; Bawendi, MG; Kirsch, DG; Brigman, BE
MLA Citation
Whitley, MJ, Cardona, DM, Lazarides, AL, Spasojevic, I, Ferrer, JM, Cahill, J, Lee, C-L, Snuderl, M, Blazer, DG, Hwang, ES, Greenup, RA, Mosca, PJ, Mito, JK, Cuneo, KC, Larrier, NA, O'Reilly, EK, Riedel, RF, Eward, WC, Strasfeld, DB, Fukumura, D, Jain, RK, Lee, WD, Griffith, LG, Bawendi, MG, Kirsch, DG, and Brigman, BE. "A mouse-human phase 1 co-clinical trial of a protease-activated fluorescent probe for imaging cancer." Science translational medicine 8.320 (January 2016): 320ra4-.
PMID
26738797
Source
epmc
Published In
Science Translational Medicine
Volume
8
Issue
320
Publish Date
2016
Start Page
320ra4
DOI
10.1126/scitranslmed.aad0293

A Fluorescence-Guided Laser Ablation System for Removal of Residual Cancer in a Mouse Model of Soft Tissue Sarcoma.

The treatment of soft tissue sarcoma (STS) generally involves tumor excision with a wide margin. Although advances in fluorescence imaging make real-time detection of cancer possible, removal is limited by the precision of the human eye and hand. Here, we describe a novel pulsed Nd:YAG laser ablation system that, when used in conjunction with a previously described molecular imaging system, can identify and ablate cancer in vivo. Mice with primary STS were injected with the protease-activatable probe LUM015 to label tumors. Resected tissues from the mice were then imaged and treated with the laser using the paired fluorescence-imaging/ laser ablation device, generating ablation clefts with sub-millimeter precision and minimal underlying tissue damage. Laser ablation was guided by fluorescence to target tumor tissues, avoiding normal structures. The selective ablation of tumor implants in vivo improved recurrence-free survival after tumor resection in a cohort of 14 mice compared to 12 mice that received no ablative therapy. This prototype system has the potential to be modified so that it can be used during surgery to improve recurrence-free survival in patients with cancer.

Authors
Lazarides, AL; Whitley, MJ; Strasfeld, DB; Cardona, DM; Ferrer, JM; Mueller, JL; Fu, HL; Bartholf DeWitt, S; Brigman, BE; Ramanujam, N; Kirsch, DG; Eward, WC
MLA Citation
Lazarides, AL, Whitley, MJ, Strasfeld, DB, Cardona, DM, Ferrer, JM, Mueller, JL, Fu, HL, Bartholf DeWitt, S, Brigman, BE, Ramanujam, N, Kirsch, DG, and Eward, WC. "A Fluorescence-Guided Laser Ablation System for Removal of Residual Cancer in a Mouse Model of Soft Tissue Sarcoma." Theranostics 6.2 (January 2016): 155-166.
Website
http://hdl.handle.net/10161/13883
PMID
26877775
Source
epmc
Published In
Theranostics
Volume
6
Issue
2
Publish Date
2016
Start Page
155
End Page
166
DOI
10.7150/thno.13536

X-Ray Psoralen Activated Cancer Therapy (X-PACT).

This work investigates X-PACT (X-ray Psoralen Activated Cancer Therapy): a new approach for the treatment of solid cancer. X-PACT utilizes psoralen, a potent anti-cancer therapeutic with current application to proliferative disease and extracorporeal photopheresis (ECP) of cutaneous T Cell Lymphoma. An immunogenic role for light-activated psoralen has been reported, contributing to long-term clinical responses. Psoralen therapies have to-date been limited to superficial or extracorporeal scenarios due to the requirement for psoralen activation by UVA light, which has limited penetration in tissue. X-PACT solves this challenge by activating psoralen with UV light emitted from novel non-tethered phosphors (co-incubated with psoralen) that absorb x-rays and re-radiate (phosphoresce) at UV wavelengths. The efficacy of X-PACT was evaluated in both in-vitro and in-vivo settings. In-vitro studies utilized breast (4T1), glioma (CT2A) and sarcoma (KP-B) cell lines. Cells were exposed to X-PACT treatments where the concentrations of drug (psoralen and phosphor) and radiation parameters (energy, dose, and dose rate) were varied. Efficacy was evaluated primarily using flow cell cytometry in combination with complimentary assays, and the in-vivo mouse study. In an in-vitro study, we show that X-PACT induces significant tumor cell apoptosis and cytotoxicity, unlike psoralen or phosphor alone (p<0.0001). We also show that apoptosis increases as doses of phosphor, psoralen, or radiation increase. Finally, in an in-vivo pilot study of BALBc mice with syngeneic 4T1 tumors, we show that the rate of tumor growth is slower with X-PACT than with saline or AMT + X-ray (p<0.0001). Overall these studies demonstrate a potential therapeutic effect for X-PACT, and provide a foundation and rationale for future studies. In summary, X-PACT represents a novel treatment approach in which well-tolerated low doses of x-ray radiation are delivered to a specific tumor site to generate UVA light which in-turn unleashes both short- and potentially long-term antitumor activity of photo-active therapeutics like psoralen.

Authors
Oldham, M; Yoon, P; Fathi, Z; Beyer, WF; Adamson, J; Liu, L; Alcorta, D; Xia, W; Osada, T; Liu, C; Yang, XY; Dodd, RD; Herndon, JE; Meng, B; Kirsch, DG; Lyerly, HK; Dewhirst, MW; Fecci, P; Walder, H; Spector, NL
MLA Citation
Oldham, M, Yoon, P, Fathi, Z, Beyer, WF, Adamson, J, Liu, L, Alcorta, D, Xia, W, Osada, T, Liu, C, Yang, XY, Dodd, RD, Herndon, JE, Meng, B, Kirsch, DG, Lyerly, HK, Dewhirst, MW, Fecci, P, Walder, H, and Spector, NL. "X-Ray Psoralen Activated Cancer Therapy (X-PACT)." PloS one 11.9 (January 2016): e0162078-.
Website
http://hdl.handle.net/10161/13034
PMID
27583569
Source
epmc
Published In
PloS one
Volume
11
Issue
9
Publish Date
2016
Start Page
e0162078
DOI
10.1371/journal.pone.0162078

Epigenetic silencing of Kruppel like factor-3 increases expression of pro-metastatic miR-182.

Accumulating evidence indicates that microRNAs (miRs) regulate cancer metastasis. We have shown that miR-182 drives sarcoma metastasis in vivo by coordinated regulation of multiple genes. Recently, we also demonstrated that in a subset of primary sarcomas that metastasize to the lung, miR-182 expression is elevated through binding of MyoD1 to the miR-182 promoter. However, it is not known if there are also transcription factors that inhibit miR-182 expression. Defining negative regulators of miR-182 expression may help explain why some sarcomas do not metastasize and may also identify pathways that can modulate miR-182 for therapeutic benefit. Here, we use an in silico screen, chromatin-immunoprecipitation, and luciferase reporter assays to discover that Kruppel like factor-3 (Klf-3) is a novel transcriptional repressor of miR-182. Knockdown of Klf-3 increases miR-182 expression, and stable overexpression of Klf-3, but not a DNA-binding mutant Klf-3, decreases miR-182 levels. Klf-3 expression is downregulated in both primary mouse and human metastatic sarcomas, and Klf-3 levels negatively correlate with miR-182 expression. Interestingly, Klf-3 also negatively regulates MyoD1, suggesting an alternative mechanism for Klf-3 to repress miR-182 expression in addition to direct binding of the miR-182 promoter. Using Methylation Specific PCR (MSP) and pyrosequencing assays, we found that Klf-3 is epigenetically silenced by DNA hypermethylation both in mouse and human sarcoma cells. Finally, we show the DNA methylation inhibitor 5'Azacytidine (Aza) restores Klf-3 expression while reducing miR-182 levels. Thus, our findings suggest that demethylating agents could potentially be used to modulate miR-182 levels as a therapeutic strategy.

Authors
Sachdeva, M; Dodd, RD; Huang, Z; Grenier, C; Ma, Y; Lev, DC; Cardona, DM; Murphy, SK; Kirsch, DG
MLA Citation
Sachdeva, M, Dodd, RD, Huang, Z, Grenier, C, Ma, Y, Lev, DC, Cardona, DM, Murphy, SK, and Kirsch, DG. "Epigenetic silencing of Kruppel like factor-3 increases expression of pro-metastatic miR-182." Cancer letters 369.1 (December 2015): 202-211.
PMID
26314219
Source
epmc
Published In
Cancer Letters
Volume
369
Issue
1
Publish Date
2015
Start Page
202
End Page
211
DOI
10.1016/j.canlet.2015.08.016

A quantitative microscopic approach to predict local recurrence based on in vivo intraoperative imaging of sarcoma tumor margins.

The goal of resection of soft tissue sarcomas located in the extremity is to preserve limb function while completely excising the tumor with a margin of normal tissue. With surgery alone, one-third of patients with soft tissue sarcoma of the extremity will have local recurrence due to microscopic residual disease in the tumor bed. Currently, a limited number of intraoperative pathology-based techniques are used to assess margin status; however, few have been widely adopted due to sampling error and time constraints. To aid in intraoperative diagnosis, we developed a quantitative optical microscopy toolbox, which includes acriflavine staining, fluorescence microscopy, and analytic techniques called sparse component analysis and circle transform to yield quantitative diagnosis of tumor margins. A series of variables were quantified from images of resected primary sarcomas and used to optimize a multivariate model. The sensitivity and specificity for differentiating positive from negative ex vivo resected tumor margins was 82 and 75%. The utility of this approach was tested by imaging the in vivo tumor cavities from 34 mice after resection of a sarcoma with local recurrence as a bench mark. When applied prospectively to images from the tumor cavity, the sensitivity and specificity for differentiating local recurrence was 78 and 82%. For comparison, if pathology was used to predict local recurrence in this data set, it would achieve a sensitivity of 29% and a specificity of 71%. These results indicate a robust approach for detecting microscopic residual disease, which is an effective predictor of local recurrence.

Authors
Mueller, JL; Fu, HL; Mito, JK; Whitley, MJ; Chitalia, R; Erkanli, A; Dodd, L; Cardona, DM; Geradts, J; Willett, RM; Kirsch, DG; Ramanujam, N
MLA Citation
Mueller, JL, Fu, HL, Mito, JK, Whitley, MJ, Chitalia, R, Erkanli, A, Dodd, L, Cardona, DM, Geradts, J, Willett, RM, Kirsch, DG, and Ramanujam, N. "A quantitative microscopic approach to predict local recurrence based on in vivo intraoperative imaging of sarcoma tumor margins." International journal of cancer 137.10 (November 2015): 2403-2412.
PMID
25994353
Source
epmc
Published In
International Journal of Cancer
Volume
137
Issue
10
Publish Date
2015
Start Page
2403
End Page
2412
DOI
10.1002/ijc.29611

Spectrotemporal CT data acquisition and reconstruction at low dose.

X-ray computed tomography (CT) is widely used, both clinically and preclinically, for fast, high-resolution anatomic imaging; however, compelling opportunities exist to expand its use in functional imaging applications. For instance, spectral information combined with nanoparticle contrast agents enables quantification of tissue perfusion levels, while temporal information details cardiac and respiratory dynamics. The authors propose and demonstrate a projection acquisition and reconstruction strategy for 5D CT (3D+dual energy+time) which recovers spectral and temporal information without substantially increasing radiation dose or sampling time relative to anatomic imaging protocols.The authors approach the 5D reconstruction problem within the framework of low-rank and sparse matrix decomposition. Unlike previous work on rank-sparsity constrained CT reconstruction, the authors establish an explicit rank-sparse signal model to describe the spectral and temporal dimensions. The spectral dimension is represented as a well-sampled time and energy averaged image plus regularly undersampled principal components describing the spectral contrast. The temporal dimension is represented as the same time and energy averaged reconstruction plus contiguous, spatially sparse, and irregularly sampled temporal contrast images. Using a nonlinear, image domain filtration approach, the authors refer to as rank-sparse kernel regression, the authors transfer image structure from the well-sampled time and energy averaged reconstruction to the spectral and temporal contrast images. This regularization strategy strictly constrains the reconstruction problem while approximately separating the temporal and spectral dimensions. Separability results in a highly compressed representation for the 5D data in which projections are shared between the temporal and spectral reconstruction subproblems, enabling substantial undersampling. The authors solved the 5D reconstruction problem using the split Bregman method and GPU-based implementations of backprojection, reprojection, and kernel regression. Using a preclinical mouse model, the authors apply the proposed algorithm to study myocardial injury following radiation treatment of breast cancer.Quantitative 5D simulations are performed using the MOBY mouse phantom. Twenty data sets (ten cardiac phases, two energies) are reconstructed with 88 μm, isotropic voxels from 450 total projections acquired over a single 360° rotation. In vivo 5D myocardial injury data sets acquired in two mice injected with gold and iodine nanoparticles are also reconstructed with 20 data sets per mouse using the same acquisition parameters (dose: ∼60 mGy). For both the simulations and the in vivo data, the reconstruction quality is sufficient to perform material decomposition into gold and iodine maps to localize the extent of myocardial injury (gold accumulation) and to measure cardiac functional metrics (vascular iodine). Their 5D CT imaging protocol represents a 95% reduction in radiation dose per cardiac phase and energy and a 40-fold decrease in projection sampling time relative to their standard imaging protocol.Their 5D CT data acquisition and reconstruction protocol efficiently exploits the rank-sparse nature of spectral and temporal CT data to provide high-fidelity reconstruction results without increased radiation dose or sampling time.

Authors
Clark, DP; Lee, C-L; Kirsch, DG; Badea, CT
MLA Citation
Clark, DP, Lee, C-L, Kirsch, DG, and Badea, CT. "Spectrotemporal CT data acquisition and reconstruction at low dose." Medical physics 42.11 (November 2015): 6317-6336.
Website
http://hdl.handle.net/10161/11181
PMID
26520724
Source
epmc
Published In
Medical physics
Volume
42
Issue
11
Publish Date
2015
Start Page
6317
End Page
6336
DOI
10.1118/1.4931407

Tailoring Adjuvant Radiation Therapy by Intraoperative Imaging to Detect Residual Cancer.

For many solid cancers, radiation therapy is offered as an adjuvant to surgical resection to lower rates of local recurrence and improve survival. However, a subset of patients treated with surgery alone will not have a local recurrence. Currently, there is no way to accurately determine which patients have microscopic residual disease in the tumor bed after surgery and therefore are most likely to benefit from adjuvant radiation therapy. To address this problem, a number of technologies have been developed to try to improve margin assessment of resected tissue and to detect residual cancer in the tumor bed. Moreover, some of these approaches have been translated from the preclinical arena into clinical trials. Here, we review different types of intraoperative molecular imaging systems for cancer. Optical imaging techniques like epi-illumination, fluorescence molecular tomography and optoacoustic imaging can be coupled with exogenous fluorescent imaging probes that accumulate in tumors passively via the enhanced permeability and retention effect or are targeted to tumor tissues based on affinity or enzyme activity. In these approaches, detection of fluorescence in the tumor bed may indicate residual disease. Protease activated probes have generated great interest because of their potential for leading to high tumor to normal contrast. Recently, the first Phase I clinical trial to assess the safety and activation of a protease activated probe was conducted. Spectroscopic methods like radiofrequency spectroscopy and Raman spectroscopy, which are based on energy absorption and scattering, respectively, have also been tested in humans and are able to distinguish between normal and tumors tissues intraoperatively. Most recently, multimodal contrast agents have been developed that target tumors and contain both fluorescent dyes and magnetic resonance imaging contrast agents, allowing for preoperative planning and intraoperative margin assessment with a single contrast agent. Further clinical testing of these various intraoperative imaging approaches may lead to more accurate methods for margin assessment and the intraoperative detection of microscopic residual disease, which could guide further resection and the use of adjuvant radiation therapy.

Authors
Whitley, MJ; Weissleder, R; Kirsch, DG
MLA Citation
Whitley, MJ, Weissleder, R, and Kirsch, DG. "Tailoring Adjuvant Radiation Therapy by Intraoperative Imaging to Detect Residual Cancer." Seminars in radiation oncology 25.4 (October 2015): 313-321. (Review)
PMID
26384279
Source
epmc
Published In
Seminars in Radiation Oncology
Volume
25
Issue
4
Publish Date
2015
Start Page
313
End Page
321
DOI
10.1016/j.semradonc.2015.05.005

Biomarkers for Predicting Radiation Response.

Authors
Kirsch, DG
MLA Citation
Kirsch, DG. "Biomarkers for Predicting Radiation Response." Seminars in radiation oncology 25.4 (October 2015): 225-226.
PMID
26384270
Source
epmc
Published In
Seminars in Radiation Oncology
Volume
25
Issue
4
Publish Date
2015
Start Page
225
End Page
226
DOI
10.1016/j.semradonc.2015.05.011

Acute DNA damage activates the tumour suppressor p53 to promote radiation-induced lymphoma.

Genotoxic cancer therapies, such as chemoradiation, cause haematological toxicity primarily by activating the tumour suppressor p53. While inhibiting p53-mediated cell death during cancer therapy ameliorates haematologic toxicity, whether it also impacts carcinogenesis remains unclear. Here we utilize a mouse model of inducible p53 short hairpin RNA (shRNA) to show that temporarily blocking p53 during total-body irradiation (TBI) not only ameliorates acute toxicity, but also improves long-term survival by preventing lymphoma development. Using Kras(LA1) mice, we show that TBI promotes the expansion of a rare population of thymocytes that express oncogenic Kras(G12D). However, blocking p53 during TBI significantly suppresses the expansion of Kras(G12D)-expressing thymocytes. Mechanistically, bone marrow transplant experiments demonstrate that TBI activates p53 to decrease the ability of bone marrow cells to suppress lymphoma development through a non-cell-autonomous mechanism. Together, our results demonstrate that the p53 response to acute DNA damage promotes the development of radiation-induced lymphoma.

Authors
Lee, C-L; Castle, KD; Moding, EJ; Blum, JM; Williams, N; Luo, L; Ma, Y; Borst, LB; Kim, Y; Kirsch, DG
MLA Citation
Lee, C-L, Castle, KD, Moding, EJ, Blum, JM, Williams, N, Luo, L, Ma, Y, Borst, LB, Kim, Y, and Kirsch, DG. "Acute DNA damage activates the tumour suppressor p53 to promote radiation-induced lymphoma." Nature communications 6 (September 24, 2015): 8477-.
PMID
26399548
Source
epmc
Published In
Nature Communications
Volume
6
Publish Date
2015
Start Page
8477
DOI
10.1038/ncomms9477

MicroRNA-16 suppresses metastasis in an orthotopic, but not autochthonous, mouse model of soft tissue sarcoma

Authors
Sachdeva, M; Whitley, MJ; Mito, JK; Ma, Y; Lev, DC; Cardona, DM; Kirsch, DG
MLA Citation
Sachdeva, M, Whitley, MJ, Mito, JK, Ma, Y, Lev, DC, Cardona, DM, and Kirsch, DG. "MicroRNA-16 suppresses metastasis in an orthotopic, but not autochthonous, mouse model of soft tissue sarcoma." Disease Models & Mechanisms 8.9 (September 1, 2015): 1169-1169.
Source
crossref
Published In
Disease models & mechanisms
Volume
8
Issue
9
Publish Date
2015
Start Page
1169
End Page
1169
DOI
10.1242/dmm.022582

The use of radiation therapy in localized high-grade soft tissue sarcoma and potential impact on survival.

It is a consensus that radiation therapy (RT) should be applied for all large, deep, high-grade soft tissue sarcomas (STS). Therefore, we investigated the National Cancer Database (NCDB) to study how these guidelines are being followed, to determine what factors may be associated with the decision not to use RT, and to see whether there was an association of RT use and survival.We retrospectively analyzed localized high-grade STS patients in the NCDB from 1998 through 2006. They were further stratified into two groups: no radiation (NRT) group and radiation (RT) group. Then, long-term survival between the two groups was evaluated using the Kaplan-Meier (KM) method with comparisons based on the log-rank test. Multiple variables were analyzed between the two groups. Propensity matching was performed secondarily to minimize the influence of confounding variables.A total of 3982 of 10,290 patients (37.8 %) did not receive RT and 6,308 patients (62.2 %) did receive RT. Patients in the NRT group were more likely to have a below-median education level (median 58.2 % vs. 60.7 %; p = 0.015) and a below-median income level (65.1 % vs. 68.6 %; p < 0.001). In addition, these patients lived farther from their treatment centers (20.2 vs. 14.8 miles, p = 0.002) and were more likely to be uninsured (5.3 % vs. 3.5 %, p < 0.001). They were less likely to receive a radical excision (55.2 % vs. 70.1 %; p < 0.001) and more likely to receive amputation (20.9 % vs. 3.3 %; p < 0.001). The 30-day mortality (1.2 % vs. 0.2 %; p < 0.001) and readmission rate (3.8 % vs. 2.8 %; p = 0.031) were higher for the NRT group. KM analysis showed that long-term survival for patients who did not receive RT was significantly lower, even after propensity score matching (p < 0.001).This large database review reveals a striking lack of utilization of RT to treat high-grade STS, which correlates with poorer survival even after propensity matching. Lower education and income levels and diminished access to medical care (insurance and distance to the facility) are associated with failing to receive RT.

Authors
Hou, C-H; Lazarides, AL; Speicher, PJ; Nussbaum, DP; Blazer, DG; Kirsch, DG; Brigman, BE; Eward, WC
MLA Citation
Hou, C-H, Lazarides, AL, Speicher, PJ, Nussbaum, DP, Blazer, DG, Kirsch, DG, Brigman, BE, and Eward, WC. "The use of radiation therapy in localized high-grade soft tissue sarcoma and potential impact on survival." Annals of surgical oncology 22.9 (September 2015): 2831-2838.
PMID
26040605
Source
epmc
Published In
Annals of Surgical Oncology
Volume
22
Issue
9
Publish Date
2015
Start Page
2831
End Page
2838
DOI
10.1245/s10434-015-4639-4

The generation and characterization of novel Col1a1FRT-Cre-ER-T2-FRT and Col1a1FRT-STOP-FRT-Cre-ER-T2 mice for sequential mutagenesis.

Novel genetically engineered mouse models using the Cre-loxP or the Flp-FRT systems have generated useful reagents to manipulate the mouse genome in a temporally-regulated and tissue-specific manner. By incorporating a constitutive Cre driver line into a mouse model in which FRT-regulated genes in other cell types are regulated by Flp-FRT recombinase, gene expression can be manipulated simultaneously in separate tissue compartments. This application of dual recombinase technology can be used to dissect the role of stromal cells in tumor development and cancer therapy. Generating mice in which Cre-ER(T2) is expressed under Flp-FRT-mediated regulation would enable step-wise manipulation of the mouse genome using dual recombinase technology. Such next-generation mouse models would enable sequential mutagenesis to better model cancer and define genes required for tumor maintenance. Here, we generated novel genetically engineered mice that activate or delete Cre-ER(T2) in response to Flp recombinase. To potentially utilize the large number of Cre-loxP-regulated transgenic alleles that have already been targeted into the Rosa26 locus, such as different reporters and mutant genes, we targeted the two novel Cre-ER(T2) alleles into the endogenous Col1a1 locus for ubiquitous expression. In the Col1a1(FRT-Cre-ER-T2-FRT) mice, Flp deletes Cre-ER(T2), so that Cre-ER(T2) is only expressed in cells that have never expressed Flp. In contrast, in the Col1a1(FRT-STOP-FRT-Cre-ER-T2) mice, Flp removes the STOP cassette to allow Cre-ER(T2) expression so that Cre-ER(T2) is only expressed in cells that previously expressed Flp. These two new novel mouse strains will be complementary to each other and will enable the exploration of complex biological questions in development, normal tissue homeostasis and cancer.

Authors
Zhang, M; Kirsch, DG
MLA Citation
Zhang, M, and Kirsch, DG. "The generation and characterization of novel Col1a1FRT-Cre-ER-T2-FRT and Col1a1FRT-STOP-FRT-Cre-ER-T2 mice for sequential mutagenesis." Disease models & mechanisms 8.9 (September 2015): 1155-1166.
PMID
26183214
Source
epmc
Published In
Disease models & mechanisms
Volume
8
Issue
9
Publish Date
2015
Start Page
1155
End Page
1166
DOI
10.1242/dmm.021204

Analysis of perioperative radiation therapy in the surgical treatment of primary and recurrent retroperitoneal sarcoma.

Radiation therapy (RT) is increasingly utilized in conjunction with surgery for the treatment of retroperitoneal soft tissue sarcomas (RPS). Despite multiple theoretical advantages of RT, its role in the surgical management of this disease remains ill defined.Patients undergoing surgery for RPS from 1990 to 2011 were identified. Patients were classified as having primary or recurrent disease, and then further stratified by the use of perioperative RT. Primary outcomes, including overall survival (OS) and recurrence-free survival (RFS), were estimated using the Kaplan-Meier method with comparisons based on the log rank test. Cox-proportional hazards modeling was used to estimate the independent effect of RT on survival.Ninety-four patients met final inclusion criteria. After adjusting for confounding variables, perioperative RT remained independently associated with a reduced risk of recurrence (HR 0.34, P < 0.01) and death (HR 0.30, P = 0.02).In this retrospective series, perioperative RT is an independent predictor of improved OS and RFS. These results provide additional support for the use of RT in the multimodality treatment of retroperitoneal sarcoma.

Authors
Lane, WO; Cramer, CK; Nussbaum, DP; Speicher, PJ; Gulack, BC; Czito, BG; Kirsch, DG; Tyler, DS; Blazer, DG
MLA Citation
Lane, WO, Cramer, CK, Nussbaum, DP, Speicher, PJ, Gulack, BC, Czito, BG, Kirsch, DG, Tyler, DS, and Blazer, DG. "Analysis of perioperative radiation therapy in the surgical treatment of primary and recurrent retroperitoneal sarcoma." Journal of surgical oncology 112.4 (September 2015): 352-358.
PMID
26238282
Source
epmc
Published In
Journal of Surgical Oncology
Volume
112
Issue
4
Publish Date
2015
Start Page
352
End Page
358
DOI
10.1002/jso.23996

Cell Death Identification in Anticancer Therapy-Letter.

Authors
Brown, JM; Wouters, BG; Kirsch, DG
MLA Citation
Brown, JM, Wouters, BG, and Kirsch, DG. "Cell Death Identification in Anticancer Therapy-Letter." Cancer research 75.17 (September 2015): 3681-. (Letter)
PMID
26286478
Source
epmc
Published In
Cancer Research
Volume
75
Issue
17
Publish Date
2015
Start Page
3681
DOI
10.1158/0008-5472.can-15-0908

MicroRNA-16 suppresses metastasis in an orthotopic, but not autochthonous, mouse model of soft tissue sarcoma.

MicroRNAs (miRNAs) can regulate tumor cell invasion and metastasis in a tumor-specific manner. We recently demonstrated that global downregulation of miRNAs after deleting dicer can promote development of distant metastases in a mouse model of primary soft tissue sarcoma (STS). In this study, we identified miRNAs that are differentially downregulated in metastatic STS in both human and mouse, and investigated the role of these miRNAs in metastasis. miRNA- TaqMan PCR arrays showed a global downregulation of miRNAs in metastatic human sarcomas. Similar analysis in mouse metastatic sarcomas revealed overlap for several downregulated miRNAs including miR-16, miR-103, miR-146a, miR-223, miR-342 and miR-511. Restoration of these downregulated miRNAs in mouse primary sarcoma cell lines showed that miR-16, but not other downregulated miRNAs, was able to significantly suppress both migration and invasion in vitro, without altering cell proliferation. In addition, orthotopic transplantation of a sarcoma cell line stably expressing miR-16 into the muscle of immunocompromised mice revealed that restoration of miR-16 can significantly decrease lung metastasis in vivo. However, no change in the rate of lung metastasis was observed when miR-16 was deleted in mouse primary sarcomas at sarcoma initiation. Taken together, these results indicate that miR-16 can have metastasis-suppressing properties both in vitro and in vivo. However, the loss-of-function experiments in autochthonous tumors indicate that loss of miR-16 is not sufficient to promote metastasis in vivo.

Authors
Sachdeva, M; Whitley, MJ; Mito, JK; Ma, Y; Lev, DC; Cardona, DM; Kirsch, DG
MLA Citation
Sachdeva, M, Whitley, MJ, Mito, JK, Ma, Y, Lev, DC, Cardona, DM, and Kirsch, DG. "MicroRNA-16 suppresses metastasis in an orthotopic, but not autochthonous, mouse model of soft tissue sarcoma." Disease models & mechanisms 8.8 (August 2015): 867-875.
PMID
26044957
Source
epmc
Published In
Disease models & mechanisms
Volume
8
Issue
8
Publish Date
2015
Start Page
867
End Page
875
DOI
10.1242/dmm.017897

Concepts and challenges in cancer risk prediction for the space radiation environment.

Cancer is an important long-term risk for astronauts exposed to protons and high-energy charged particles during travel and residence on asteroids, the moon, and other planets. NASA's Biomedical Critical Path Roadmap defines the carcinogenic risks of radiation exposure as one of four type I risks. A type I risk represents a demonstrated, serious problem with no countermeasure concepts, and may be a potential "show-stopper" for long duration spaceflight. Estimating the carcinogenic risks for humans who will be exposed to heavy ions during deep space exploration has very large uncertainties at present. There are no human data that address risk from extended exposure to complex radiation fields. The overarching goal in this area to improve risk modeling is to provide biological insight and mechanistic analysis of radiation quality effects on carcinogenesis. Understanding mechanisms will provide routes to modeling and predicting risk and designing countermeasures. This white paper reviews broad issues related to experimental models and concepts in space radiation carcinogenesis as well as the current state of the field to place into context recent findings and concepts derived from the NASA Space Radiation Program.

Authors
Barcellos-Hoff, MH; Blakely, EA; Burma, S; Fornace, AJ; Gerson, S; Hlatky, L; Kirsch, DG; Luderer, U; Shay, J; Wang, Y; Weil, MM
MLA Citation
Barcellos-Hoff, MH, Blakely, EA, Burma, S, Fornace, AJ, Gerson, S, Hlatky, L, Kirsch, DG, Luderer, U, Shay, J, Wang, Y, and Weil, MM. "Concepts and challenges in cancer risk prediction for the space radiation environment." Life sciences in space research 6 (July 17, 2015): 92-103. (Review)
PMID
26256633
Source
epmc
Published In
Life sciences in space research
Volume
6
Publish Date
2015
Start Page
92
End Page
103
DOI
10.1016/j.lssr.2015.07.006

Long-term Oncologic Outcomes After Neoadjuvant Radiation Therapy for Retroperitoneal Sarcomas.

To evaluate long-term survival among patients undergoing radiation therapy (RT), followed by surgical resection of retroperitoneal sarcomas (RPS).Despite a lack of level 1 evidence supporting neoadjuvant RT for RPS, its use has increased substantially over the past decade.The 1998-2011 National Cancer Data Base was queried to identify patients who underwent resection of RPS. Subjects were grouped by use of neoadjuvant RT. Perioperative variables and outcomes were compared. Multivariable logistic regression was performed to assess predictors of neoadjuvant RT. Groups were propensity matched using a 2:1 nearest neighbor algorithm and short-term outcomes were compared. Finally, long-term survival was evaluated using the Kaplan-Meier method, with comparisons based on the log-rank test.A total of 11,324 patients were identified. Neoadjuvant RT was administered to 696 patients (6.1%). During the study period, preoperative RT use increased from 4% to nearly 15%. Male sex, tumor size larger than 5 cm, treatment at an academic/research program, and higher tumor grade all predicted neoadjuvant RT administration. After propensity matching, the only difference in baseline characteristics was the use of neoadjuvant chemotherapy. Although neoadjuvant RT was associated with a higher rate of negative margins (77.5% vs 73.0%; P = 0.014), there was no corresponding improvement in 5-year survival (53.2% vs 54.2%; P = 0.695).Despite the increasing use of neoadjuvant RT for patients with RPS, the survival benefit associated with this treatment modality remains unclear. Continued investigation is needed to better define the role of RT among patients with RPS.

Authors
Nussbaum, DP; Speicher, PJ; Gulack, BC; Ganapathi, AM; Englum, BR; Kirsch, DG; Tyler, DS; Blazer, DG
MLA Citation
Nussbaum, DP, Speicher, PJ, Gulack, BC, Ganapathi, AM, Englum, BR, Kirsch, DG, Tyler, DS, and Blazer, DG. "Long-term Oncologic Outcomes After Neoadjuvant Radiation Therapy for Retroperitoneal Sarcomas." Annals of surgery 262.1 (July 2015): 163-170.
PMID
25185464
Source
epmc
Published In
Annals of Surgery
Volume
262
Issue
1
Publish Date
2015
Start Page
163
End Page
170
DOI
10.1097/sla.0000000000000840

Significant Reduction of Late Toxicities in Patients With Extremity Sarcoma Treated With Image-Guided Radiation Therapy to a Reduced Target Volume: Results of Radiation Therapy Oncology Group RTOG-0630 Trial.

We performed a multi-institutional prospective phase II trial to assess late toxicities in patients with extremity soft tissue sarcoma (STS) treated with preoperative image-guided radiation therapy (IGRT) to a reduced target volume.Patients with extremity STS received IGRT with (cohort A) or without (cohort B) chemotherapy followed by limb-sparing resection. Daily pretreatment images were coregistered with digitally reconstructed radiographs so that the patient position could be adjusted before each treatment. All patients received IGRT to reduced tumor volumes according to strict protocol guidelines. Late toxicities were assessed at 2 years.In all, 98 patients were accrued (cohort A, 12; cohort B, 86). Cohort A was closed prematurely because of poor accrual and is not reported. Seventy-nine eligible patients from cohort B form the basis of this report. At a median follow-up of 3.6 years, five patients did not have surgery because of disease progression. There were five local treatment failures, all of which were in field. Of the 57 patients assessed for late toxicities at 2 years, 10.5% experienced at least one grade ≥ 2 toxicity as compared with 37% of patients in the National Cancer Institute of Canada SR2 (CAN-NCIC-SR2: Phase III Randomized Study of Pre- vs Postoperative Radiotherapy in Curable Extremity Soft Tissue Sarcoma) trial receiving preoperative radiation therapy without IGRT (P < .001).The significant reduction of late toxicities in patients with extremity STS who were treated with preoperative IGRT and absence of marginal-field recurrences suggest that the target volumes used in the Radiation Therapy Oncology Group RTOG-0630 (A Phase II Trial of Image-Guided Preoperative Radiotherapy for Primary Soft Tissue Sarcomas of the Extremity) study are appropriate for preoperative IGRT for extremity STS.

Authors
Wang, D; Zhang, Q; Eisenberg, BL; Kane, JM; Li, XA; Lucas, D; Petersen, IA; DeLaney, TF; Freeman, CR; Finkelstein, SE; Hitchcock, YJ; Bedi, M; Singh, AK; Dundas, G; Kirsch, DG
MLA Citation
Wang, D, Zhang, Q, Eisenberg, BL, Kane, JM, Li, XA, Lucas, D, Petersen, IA, DeLaney, TF, Freeman, CR, Finkelstein, SE, Hitchcock, YJ, Bedi, M, Singh, AK, Dundas, G, and Kirsch, DG. "Significant Reduction of Late Toxicities in Patients With Extremity Sarcoma Treated With Image-Guided Radiation Therapy to a Reduced Target Volume: Results of Radiation Therapy Oncology Group RTOG-0630 Trial." Journal of clinical oncology : official journal of the American Society of Clinical Oncology 33.20 (July 2015): 2231-2238.
PMID
25667281
Source
epmc
Published In
Journal of Clinical Oncology
Volume
33
Issue
20
Publish Date
2015
Start Page
2231
End Page
2238
DOI
10.1200/jco.2014.58.5828

Treatment Guidelines for Preoperative Radiation Therapy for Retroperitoneal Sarcoma: Preliminary Consensus of an International Expert Panel.

PURPOSE: Evidence for external beam radiation therapy (RT) as part of treatment for retroperitoneal sarcoma (RPS) is limited. Preoperative RT is the subject of a current randomized trial, but the results will not be available for many years. In the meantime, many practitioners use preoperative RT for RPS, and although this approach is used in practice, there are no radiation treatment guidelines. An international expert panel was convened to develop consensus treatment guidelines for preoperative RT for RPS. METHODS AND MATERIALS: An expert panel of 15 academic radiation oncologists who specialize in the treatment of sarcoma was assembled. A systematic review of reports related to RT for RPS, RT for extremity sarcoma, and RT-related toxicities for organs at risk was performed. Due to the paucity of high-quality published data on the subject of RT for RPS, consensus recommendations were based largely on expert opinion derived from clinical experience and extrapolation of relevant published reports. It is intended that these clinical practice guidelines be updated as pertinent data become available. RESULTS: Treatment guidelines for preoperative RT for RPS are presented. CONCLUSIONS: An international panel of radiation oncologists who specialize in sarcoma reached consensus guidelines for preoperative RT for RPS. Many of the recommendations are based on expert opinion because of the absence of higher level evidence and, thus, are best regarded as preliminary. We emphasize that the role of preoperative RT for RPS has not been proven, and we await data from the European Organization for Research and Treatment of Cancer (EORTC) study of preoperative radiotherapy plus surgery versus surgery alone for patients with RPS. Further data are also anticipated pertaining to normal tissue dose constraints, particularly for bowel tolerance. Nonetheless, as we await these data, the guidelines herein can be used to establish treatment uniformity to aid future assessments of efficacy and toxicity.

Authors
Baldini, EH; Wang, D; Haas, RLM; Catton, CN; Indelicato, DJ; Kirsch, DG; Roberge, D; Salerno, K; Deville, C; Guadagnolo, BA; O'Sullivan, B; Petersen, IA; Le Pechoux, C; Abrams, RA; DeLaney, TF
MLA Citation
Baldini, EH, Wang, D, Haas, RLM, Catton, CN, Indelicato, DJ, Kirsch, DG, Roberge, D, Salerno, K, Deville, C, Guadagnolo, BA, O'Sullivan, B, Petersen, IA, Le Pechoux, C, Abrams, RA, and DeLaney, TF. "Treatment Guidelines for Preoperative Radiation Therapy for Retroperitoneal Sarcoma: Preliminary Consensus of an International Expert Panel." International journal of radiation oncology, biology, physics 92.3 (July 2015): 602-612. (Review)
PMID
26068493
Source
epmc
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
92
Issue
3
Publish Date
2015
Start Page
602
End Page
612
DOI
10.1016/j.ijrobp.2015.02.013

HIF-1 Alpha Regulates the Response of Primary Sarcomas to Radiation Therapy through a Cell Autonomous Mechanism.

Hypoxia is a major cause of radiation resistance, which may predispose to local recurrence after radiation therapy. While hypoxia increases tumor cell survival after radiation exposure because there is less oxygen to oxidize damaged DNA, it remains unclear whether signaling pathways triggered by hypoxia contribute to radiation resistance. For example, intratumoral hypoxia can increase hypoxia inducible factor 1 alpha (HIF-1α), which may regulate pathways that contribute to radiation sensitization or radiation resistance. To clarify the role of HIF-1α in regulating tumor response to radiation, we generated a novel genetically engineered mouse model of soft tissue sarcoma with an intact or deleted HIF-1α. Deletion of HIF-1α sensitized primary sarcomas to radiation exposure in vivo. Moreover, cell lines derived from primary sarcomas lacking HIF-1α, or in which HIF-1α was knocked down, had decreased clonogenic survival in vitro, demonstrating that HIF-1α can promote radiation resistance in a cell autonomous manner. In HIF-1α-intact and -deleted sarcoma cells, radiation-induced reactive oxygen species, DNA damage repair and activation of autophagy were similar. However, sarcoma cells lacking HIF-1α had impaired mitochondrial biogenesis and metabolic response after irradiation, which might contribute to radiation resistance. These results show that HIF-1α promotes radiation resistance in a cell autonomous manner.

Authors
Zhang, M; Qiu, Q; Li, Z; Sachdeva, M; Min, H; Cardona, DM; DeLaney, TF; Han, T; Ma, Y; Luo, L; Ilkayeva, OR; Lui, K; Nichols, AG; Newgard, CB; Kastan, MB; Rathmell, JC; Dewhirst, MW; Kirsch, DG
MLA Citation
Zhang, M, Qiu, Q, Li, Z, Sachdeva, M, Min, H, Cardona, DM, DeLaney, TF, Han, T, Ma, Y, Luo, L, Ilkayeva, OR, Lui, K, Nichols, AG, Newgard, CB, Kastan, MB, Rathmell, JC, Dewhirst, MW, and Kirsch, DG. "HIF-1 Alpha Regulates the Response of Primary Sarcomas to Radiation Therapy through a Cell Autonomous Mechanism." Radiation research 183.6 (June 2015): 594-609.
PMID
25973951
Source
epmc
Published In
Radiation Research
Volume
183
Issue
6
Publish Date
2015
Start Page
594
End Page
609
DOI
10.1667/rr14016.1

Inhibition of vascular endothelial growth factor A and hypoxia-inducible factor 1α maximizes the effects of radiation in sarcoma mouse models through destruction of tumor vasculature.

To examine the addition of genetic or pharmacologic inhibition of hypoxia-inducible factor 1α (HIF-1α) to radiation therapy (RT) and vascular endothelial growth factor A (VEGF-A) inhibition (ie trimodality therapy) for soft-tissue sarcoma.Hypoxia-inducible factor 1α was inhibited using short hairpin RNA or low metronomic doses of doxorubicin, which blocks HIF-1α binding to DNA. Trimodality therapy was examined in a mouse xenograft model and a genetically engineered mouse model of sarcoma, as well as in vitro in tumor endothelial cells (ECs) and 4 sarcoma cell lines.In both mouse models, any monotherapy or bimodality therapy resulted in tumor growth beyond 250 mm(3) within the 12-day treatment period, but trimodality therapy with RT, VEGF-A inhibition, and HIF-1α inhibition kept tumors at <250 mm(3) for up to 30 days. Trimodality therapy on tumors reduced HIF-1α activity as measured by expression of nuclear HIF-1α by 87% to 95% compared with RT alone, and cytoplasmic carbonic anhydrase 9 by 79% to 82%. Trimodality therapy also increased EC-specific apoptosis 2- to 4-fold more than RT alone and reduced microvessel density by 75% to 82%. When tumor ECs were treated in vitro with trimodality therapy under hypoxia, there were significant decreases in proliferation and colony formation and increases in DNA damage (as measured by Comet assay and γH2AX expression) and apoptosis (as measured by cleaved caspase 3 expression). Trimodality therapy had much less pronounced effects when 4 sarcoma cell lines were examined in these same assays.Inhibition of HIF-1α is highly effective when combined with RT and VEGF-A inhibition in blocking sarcoma growth by maximizing DNA damage and apoptosis in tumor ECs, leading to loss of tumor vasculature.

Authors
Lee, H-J; Yoon, C; Park, DJ; Kim, Y-J; Schmidt, B; Lee, Y-J; Tap, WD; Eisinger-Mathason, TSK; Choy, E; Kirsch, DG; Simon, MC; Yoon, SS
MLA Citation
Lee, H-J, Yoon, C, Park, DJ, Kim, Y-J, Schmidt, B, Lee, Y-J, Tap, WD, Eisinger-Mathason, TSK, Choy, E, Kirsch, DG, Simon, MC, and Yoon, SS. "Inhibition of vascular endothelial growth factor A and hypoxia-inducible factor 1α maximizes the effects of radiation in sarcoma mouse models through destruction of tumor vasculature." International journal of radiation oncology, biology, physics 91.3 (March 2015): 621-630.
PMID
25544668
Source
epmc
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
91
Issue
3
Publish Date
2015
Start Page
621
End Page
630
DOI
10.1016/j.ijrobp.2014.10.047

Tumor cells, but not endothelial cells, mediate eradication of primary sarcomas by stereotactic body radiation therapy.

Cancer clinics currently use high-dose stereotactic body radiation therapy as a curative treatment for several kinds of cancers. However, the contribution of vascular endothelial cells to tumor response to radiation remains controversial. Using dual recombinase technology, we generated primary sarcomas in mice with targeted genetic mutations specifically in tumor cells or endothelial cells. We selectively mutated the proapoptotic gene Bax or the DNA damage response gene Atm to genetically manipulate the radiosensitivity of endothelial cells in primary soft tissue sarcomas. Bax deletion from endothelial cells did not affect radiation-induced cell death in tumor endothelial cells or sarcoma response to radiation therapy. Although Atm deletion increased endothelial cell death after radiation therapy, deletion of Atm from endothelial cells failed to enhance sarcoma eradication. In contrast, deletion of Atm from tumor cells increased sarcoma eradication by radiation therapy. These results demonstrate that tumor cells, rather than endothelial cells, are critical targets that regulate sarcoma eradication by radiation therapy. Treatment with BEZ235, a small-molecule protein kinase inhibitor, radiosensitized primary sarcomas more than the heart. These results suggest that inhibiting ATM kinase during radiation therapy is a viable strategy for radiosensitization of some tumors.

Authors
Moding, EJ; Castle, KD; Perez, BA; Oh, P; Min, HD; Norris, H; Ma, Y; Cardona, DM; Lee, C-L; Kirsch, DG
MLA Citation
Moding, EJ, Castle, KD, Perez, BA, Oh, P, Min, HD, Norris, H, Ma, Y, Cardona, DM, Lee, C-L, and Kirsch, DG. "Tumor cells, but not endothelial cells, mediate eradication of primary sarcomas by stereotactic body radiation therapy." Science translational medicine 7.278 (March 2015): 278ra34-.
PMID
25761890
Source
epmc
Published In
Science Translational Medicine
Volume
7
Issue
278
Publish Date
2015
Start Page
278ra34
DOI
10.1126/scitranslmed.aaa4214

Acute tissue injury activates satellite cells and promotes sarcoma formation via the HGF/c-MET signaling pathway.

Some patients with soft-tissue sarcoma (STS) report a history of injury at the site of their tumor. Although this phenomenon is widely reported, there are relatively few experimental systems that have directly assessed the role of injury in sarcoma formation. We recently described a mouse model of STS whereby p53 is deleted and oncogenic Kras is activated in muscle satellite cells via a Pax7(CreER) driver following intraperitoneal injection with tamoxifen. Here, we report that after systemic injection of tamoxifen, the vast majority of Pax7-expressing cells remain quiescent despite mutation of p53 and Kras. The fate of these muscle progenitors is dramatically altered by tissue injury, which leads to faster kinetics of sarcoma formation. In adult muscle, quiescent satellite cells will transition into an active state in response to hepatocyte growth factor (HGF). We show that modulating satellite cell quiescence via intramuscular injection of HGF increases the penetrance of sarcoma formation at the site of injection, which is dependent on its cognate receptor c-MET. Unexpectedly, the tumor-promoting effect of tissue injury also requires c-Met. These results reveal a mechanism by which HGF/c-MET signaling promotes tumor formation after tissue injury in a mouse model of primary STS, and they may explain why some patients develop a STS at the site of injury.

Authors
Van Mater, D; Añó, L; Blum, JM; Webster, MT; Huang, W; Williams, N; Ma, Y; Cardona, DM; Fan, C-M; Kirsch, DG
MLA Citation
Van Mater, D, Añó, L, Blum, JM, Webster, MT, Huang, W, Williams, N, Ma, Y, Cardona, DM, Fan, C-M, and Kirsch, DG. "Acute tissue injury activates satellite cells and promotes sarcoma formation via the HGF/c-MET signaling pathway." Cancer research 75.3 (February 2015): 605-614.
PMID
25503558
Source
epmc
Published In
Cancer Research
Volume
75
Issue
3
Publish Date
2015
Start Page
605
End Page
614
DOI
10.1158/0008-5472.can-14-2527

Investigating the accuracy of microstereotactic-body-radiotherapy utilizing anatomically accurate 3D printed rodent-morphic dosimeters.

Sophisticated small animal irradiators, incorporating cone-beam-CT image-guidance, have recently been developed which enable exploration of the efficacy of advanced radiation treatments in the preclinical setting. Microstereotactic-body-radiation-therapy (microSBRT) is one technique of interest, utilizing field sizes in the range of 1-15 mm. Verification of the accuracy of microSBRT treatment delivery is challenging due to the lack of available methods to comprehensively measure dose distributions in representative phantoms with sufficiently high spatial resolution and in 3 dimensions (3D). This work introduces a potential solution in the form of anatomically accurate rodent-morphic 3D dosimeters compatible with ultrahigh resolution (0.3 mm(3)) optical computed tomography (optical-CT) dose read-out.Rodent-morphic dosimeters were produced by 3D-printing molds of rodent anatomy directly from contours defined on x-ray CT data sets of rats and mice, and using these molds to create tissue-equivalent radiochromic 3D dosimeters from Presage. Anatomically accurate spines were incorporated into some dosimeters, by first 3D printing the spine mold, then forming a high-Z bone equivalent spine insert. This spine insert was then set inside the tissue equivalent body mold. The high-Z spinal insert enabled representative cone-beam CT IGRT targeting. On irradiation, a linear radiochromic change in optical-density occurs in the dosimeter, which is proportional to absorbed dose, and was read out using optical-CT in high-resolution (0.5 mm isotropic voxels). Optical-CT data were converted to absolute dose in two ways: (i) using a calibration curve derived from other Presage dosimeters from the same batch, and (ii) by independent measurement of calibrated dose at a point using a novel detector comprised of a yttrium oxide based nanocrystalline scintillator, with a submillimeter active length. A microSBRT spinal treatment was delivered consisting of a 180° continuous arc at 225 kVp with a 20 × 10 mm field size. Dose response was evaluated using both the Presage/optical-CT 3D dosimetry system described above, and independent verification in select planes using EBT2 radiochromic film placed inside rodent-morphic dosimeters that had been sectioned in half.Rodent-morphic 3D dosimeters were successfully produced from Presage radiochromic material by utilizing 3D printed molds of rat CT contours. The dosimeters were found to be compatible with optical-CT dose readout in high-resolution 3D (0.5 mm isotropic voxels) with minimal artifacts or noise. Cone-beam CT image guidance was possible with these dosimeters due to sufficient contrast between high-Z spinal inserts and tissue equivalent Presage material (CNR ∼10 on CBCT images). Dose at isocenter measured with optical-CT was found to agree with nanoscintillator measurement to within 2.8%. Maximum dose in line profiles taken through Presage and film dose slices agreed within 3%, with FWHM measurements through each profile found to agree within 2%.This work demonstrates the feasibility of using 3D printing technology to make anatomically accurate Presage rodent-morphic dosimeters incorporating spinal-mimicking inserts. High quality optical-CT 3D dosimetry is feasible on these dosimeters, despite the irregular surfaces and implanted inserts. The ability to measure dose distributions in anatomically accurate phantoms represents a powerful useful additional verification tool for preclinical microSBRT.

Authors
Bache, ST; Juang, T; Belley, MD; Koontz, BF; Adamovics, J; Yoshizumi, TT; Kirsch, DG; Oldham, M
MLA Citation
Bache, ST, Juang, T, Belley, MD, Koontz, BF, Adamovics, J, Yoshizumi, TT, Kirsch, DG, and Oldham, M. "Investigating the accuracy of microstereotactic-body-radiotherapy utilizing anatomically accurate 3D printed rodent-morphic dosimeters." Medical physics 42.2 (February 2015): 846-855.
PMID
25652497
Source
epmc
Published In
Medical physics
Volume
42
Issue
2
Publish Date
2015
Start Page
846
End Page
855
DOI
10.1118/1.4905489

Low- and high-LET radiation drives clonal expansion of lung progenitor cells in vivo.

Abundant populations of epithelial progenitor cells maintain the epithelium along the proximal-to-distal axis of the airway. Exposure of lung tissue to ionizing radiation leads to tissue remodeling and potential cancer initiation or progression. However, little is known about the effects of ionizing radiation on airway epithelial progenitor cells. We hypothesized that ionizing radiation exposure will alter the behavior of airway epithelial progenitor cells in a radiation dose- and quality-dependent manner. To address this hypothesis, we cultured primary airway epithelial cells isolated from mice exposed to various doses of 320 kVp X ray or 600 MeV/nucleon (56)Fe ions in a 3D epithelial-fibroblast co-culture system. Colony-forming efficiency of the airway epithelial progenitor cells was assessed at culture day 14. In vivo clonogenic and proliferative potentials of airway epithelial progenitor cells were measured after exposure to ionizing radiation by lineage tracing and IdU incorporation. Exposure to both X rays and (56)Fe resulted in a dose-dependent decrease in the ability of epithelial progenitors to form colonies in vitro. In vivo evidence for increased clonogenic expansion of epithelial progenitors was observed after exposure to both X rays and (56)Fe. Interestingly, we found no significant increase in the epithelial proliferative index, indicating that ionizing radiation does not promote increased turnover of the airway epithelium. Therefore, we propose a model in which radiation induces a dose-dependent decrease in the pool of available progenitor cells, leaving fewer progenitors able to maintain the airway long-term. This work provides novel insights into the effects of ionizing radiation exposure on airway epithelial progenitor cell behavior.

Authors
Farin, AM; Manzo, ND; Kirsch, DG; Stripp, BR
MLA Citation
Farin, AM, Manzo, ND, Kirsch, DG, and Stripp, BR. "Low- and high-LET radiation drives clonal expansion of lung progenitor cells in vivo." Radiation research 183.1 (January 7, 2015): 124-132.
PMID
25564721
Source
epmc
Published In
Radiation Research
Volume
183
Issue
1
Publish Date
2015
Start Page
124
End Page
132
DOI
10.1667/rr13878.1

Rank-sparsity constrained, spectro-temporal reconstruction for retrospectively gated, dynamic CT

© 2015 SPIE. Relative to prospective projection gating, retrospective projection gating for dynamic CT applications allows fast imaging times, minimizing the potential for physiological and anatomic variability. Preclinically, fast imaging is attractive due to the rapid clearance of low molecular weight contrast agents and the rapid heart rate of rodents. Clinically, retrospective gating is relevant for intraoperative C-arm CT. More generally, retrospective sampling provides an opportunity for significant reduction in x-ray dose within the framework of compressive sensing theory and sparsity-constrained iterative reconstruction. Even so, CT reconstruction from projections with random temporal sampling is a very poorly conditioned inverse problem, requiring high fidelity regularization to minimize variability in the reconstructed results. Here, we introduce a highly novel data acquisition and regularization strategy for spectro-temporal (5D) CT reconstruction from retrospectively gated projections. We show that by taking advantage of the rank-sparse structure and separability of the temporal and spectral reconstruction sub-problems, being able to solve each sub-problem independently effectively guarantees that we can solve both problems together. In this paper, we show 4D simulation results (2D + 2 energies + time) using the proposed technique and compare them with two competing techniques - spatio-temporal total variation minimization and prior image constrained compressed sensing. We also show in vivo, 5D (3D + 2 energies + time) myocardial injury data acquired in a mouse, reconstructing 20 data sets (10 phases, 2 energies) and performing material decomposition from data acquired over a single rotation (360°, dose: ∼60 mGy).

Authors
Clark, DP; Lee, CL; Kirsch, DG; Badea, CT
MLA Citation
Clark, DP, Lee, CL, Kirsch, DG, and Badea, CT. "Rank-sparsity constrained, spectro-temporal reconstruction for retrospectively gated, dynamic CT." January 1, 2015.
Source
scopus
Published In
Proceedings of SPIE
Volume
9412
Publish Date
2015
DOI
10.1117/12.2081379

Methods to generate genetically engineered mouse models of soft tissue sarcoma.

We discuss the generation of primary soft tissue sarcomas in mice using the Cre-loxP system to activate conditional mutations in oncogenic Kras and the tumor suppressor p53 (LSL-Kras(G12D/+); p53(flox/flox)). Sarcomas can be generated either by adenoviral delivery of Cre recombinase, activation of transgenic Cre recombinase with tamoxifen, or through transplantation of isolated satellite cells with Cre activation in vitro. Various applications of these models are discussed, including anticancer therapies, metastasis, in vivo imaging, and genetic requirements for tumorigenesis.

Authors
Dodd, RD; Añó, L; Blum, JM; Li, Z; Van Mater, D; Kirsch, DG
MLA Citation
Dodd, RD, Añó, L, Blum, JM, Li, Z, Van Mater, D, and Kirsch, DG. "Methods to generate genetically engineered mouse models of soft tissue sarcoma." Methods in molecular biology (Clifton, N.J.) 1267 (January 2015): 283-295.
PMID
25636474
Source
epmc
Published In
Methods in molecular biology (Clifton, N.J.)
Volume
1267
Publish Date
2015
Start Page
283
End Page
295
DOI
10.1007/978-1-4939-2297-0_13

The Use of Radiation Therapy in Well-Differentiated Soft Tissue Sarcoma of the Extremities: An NCDB Review.

Objective. This study investigated patterns of utilization of radiation therapy (RT) and correlated this with overall survival by assessing patients with well-differentiated soft tissue sarcoma of the extremity (STS-E) in the National Cancer Database (NCDB). Methods. All patients diagnosed with well-differentiated STS-E between 1998 and 2006 were identified in the NCDB. Patients were stratified by use of surgery alone versus use of adjuvant RT after surgery and analyzed using multivariate analysis, Kaplan-Meier analysis, and propensity matching. Results. 2113 patients with well-differentiated STS-E were identified in the NCDB for inclusion with a mean follow-up time of 74 months. 69% of patients were treated with surgery alone, while 26% were treated with surgery followed by adjuvant RT. Patients undergoing amputation were less likely to receive adjuvant RT. There was no difference in overall survival between patients with well-differentiated STS treated with surgery alone and those patients who received adjuvant RT. Conclusions. In the United States, adjuvant RT is being utilized in a quarter of patients being treated for well-differentiated STS-E. While the use of adjuvant RT may be viewed as a means to facilitate limb salvage, this large national database review confirms no survival benefit, regardless of tumor size or margin status.

Authors
Lazarides, AL; Eward, WC; Speicher, PJ; Hou, C-H; Nussbaum, DP; Green, C; Blazer, DG; Kirsch, DG; Brigman, BE
MLA Citation
Lazarides, AL, Eward, WC, Speicher, PJ, Hou, C-H, Nussbaum, DP, Green, C, Blazer, DG, Kirsch, DG, and Brigman, BE. "The Use of Radiation Therapy in Well-Differentiated Soft Tissue Sarcoma of the Extremities: An NCDB Review." Sarcoma 2015 (January 2015): 186581-.
PMID
26064077
Source
epmc
Published In
Sarcoma
Volume
2015
Publish Date
2015
Start Page
186581
DOI
10.1155/2015/186581

A Plasmonic Gold Nanostar Theranostic Probe for In Vivo Tumor Imaging and Photothermal Therapy.

Nanomedicine has attracted increasing attention in recent years, because it offers great promise to provide personalized diagnostics and therapy with improved treatment efficacy and specificity. In this study, we developed a gold nanostar (GNS) probe for multi-modality theranostics including surface-enhanced Raman scattering (SERS) detection, x-ray computed tomography (CT), two-photon luminescence (TPL) imaging, and photothermal therapy (PTT). We performed radiolabeling, as well as CT and optical imaging, to investigate the GNS probe's biodistribution and intratumoral uptake at both macroscopic and microscopic scales. We also characterized the performance of the GNS nanoprobe for in vitro photothermal heating and in vivo photothermal ablation of primary sarcomas in mice. The results showed that 30-nm GNS have higher tumor uptake, as well as deeper penetration into tumor interstitial space compared to 60-nm GNS. In addition, we found that a higher injection dose of GNS can increase the percentage of tumor uptake. We also demonstrated the GNS probe's superior photothermal conversion efficiency with a highly concentrated heating effect due to a tip-enhanced plasmonic effect. In vivo photothermal therapy with a near-infrared (NIR) laser under the maximum permissible exposure (MPE) led to ablation of aggressive tumors containing GNS, but had no effect in the absence of GNS. This multifunctional GNS probe has the potential to be used for in vivo biosensing, preoperative CT imaging, intraoperative detection with optical methods (SERS and TPL), as well as image-guided photothermal therapy.

Authors
Liu, Y; Ashton, JR; Moding, EJ; Yuan, H; Register, JK; Fales, AM; Choi, J; Whitley, MJ; Zhao, X; Qi, Y; Ma, Y; Vaidyanathan, G; Zalutsky, MR; Kirsch, DG; Badea, CT; Vo-Dinh, T
MLA Citation
Liu, Y, Ashton, JR, Moding, EJ, Yuan, H, Register, JK, Fales, AM, Choi, J, Whitley, MJ, Zhao, X, Qi, Y, Ma, Y, Vaidyanathan, G, Zalutsky, MR, Kirsch, DG, Badea, CT, and Vo-Dinh, T. "A Plasmonic Gold Nanostar Theranostic Probe for In Vivo Tumor Imaging and Photothermal Therapy." Theranostics 5.9 (January 2015): 946-960.
Website
http://hdl.handle.net/10161/11045
PMID
26155311
Source
epmc
Published In
Theranostics
Volume
5
Issue
9
Publish Date
2015
Start Page
946
End Page
960
DOI
10.7150/thno.11974

Treatment Planning and Delivery of Whole Brain Irradiation with Hippocampal Avoidance in Rats.

Despite the clinical benefit of whole brain radiotherapy (WBRT), patients and physicians are concerned by the long-term impact on cognitive functioning. Many studies investigating the molecular and cellular impact of WBRT have used rodent models. However, there has not been a rodent protocol comparable to the recently reported Radiation Therapy Oncology Group (RTOG) protocol for WBRT with hippocampal avoidance (HA) which is intended to spare cognitive function. The aim of this study was to develop a hippocampal-sparing WBRT protocol in Wistar rats.The technical and clinical challenges encountered in hippocampal sparing during rat WBRT are substantial. Three key challenges were identified: hippocampal localization, treatment planning, and treatment localization. Hippocampal localization was achieved with sophisticated imaging techniques requiring deformable registration of a rat MRI atlas with a high resolution MRI followed by fusion via rigid registration to a CBCT. Treatment planning employed a Monte Carlo dose calculation in SmART-Plan and creation of 0.5 cm thick lead blocks custom-shaped to match DRR projections. Treatment localization necessitated the on-board image-guidance capability of the XRAD C225Cx micro-CT/micro-irradiator (Precision X-Ray). Treatment was accomplished with opposed lateral fields with 225 KVp X-rays at a current of 13 mA filtered through 0.3 mm of copper using a 40x40 mm square collimator and the lead blocks. A single fraction of 4 Gy was delivered (2 Gy per lateral field) with a 41 second beam on time per field at a dose rate of 304.5 cGy/min. Dosimetric verification of hippocampal sparing was performed using radiochromic film. In vivo verification of HA was performed after delivery of a single 4 Gy fraction either with or without HA using γ-H2Ax staining of tissue sections from the brain to quantify the amount of DNA damage in rats treated with HA, WBRT, or sham-irradiated (negative controls).The mean dose delivered to radiochromic film beneath the hippocampal block was 0.52 Gy compared to 3.93 Gy without the block, indicating an 87% reduction in the dose delivered to the hippocampus. This difference was consistent with doses predicted by Monte Carlo dose calculation. The Dose Volume Histogram (DVH) generated via Monte Carlo simulation showed an underdose of the target volume (brain minus hippocampus) with 50% of the target volume receiving 100% of the prescription isodose as a result of the lateral blocking techniques sparing some midline thalamic and subcortical tissue. Staining of brain sections with anti-phospho-Histone H2A.X (reflecting double-strand DNA breaks) demonstrated that this treatment protocol limited radiation dose to the hippocampus in vivo. The mean signal intensity from γ-H2Ax staining in the cortex was not significantly different from the signal intensity in the cortex of rats treated with WBRT (5.40 v. 5.75, P = 0.32). In contrast, the signal intensity in the hippocampus of rats treated with HA was significantly lower than rats treated with WBRT (4.55 v. 6.93, P = 0.012).Despite the challenges of planning conformal treatments for small volumes in rodents, our dosimetric and in vivo data show that WBRT with HA is feasible in rats. This study provides a useful platform for further application and refinement of the technique.

Authors
Cramer, CK; Yoon, SW; Reinsvold, M; Joo, KM; Norris, H; Hood, RC; Adamson, JD; Klein, RC; Kirsch, DG; Oldham, M
MLA Citation
Cramer, CK, Yoon, SW, Reinsvold, M, Joo, KM, Norris, H, Hood, RC, Adamson, JD, Klein, RC, Kirsch, DG, and Oldham, M. "Treatment Planning and Delivery of Whole Brain Irradiation with Hippocampal Avoidance in Rats." PloS one 10.12 (January 2015): e0143208-.
PMID
26636762
Source
epmc
Published In
PloS one
Volume
10
Issue
12
Publish Date
2015
Start Page
e0143208
DOI
10.1371/journal.pone.0143208

Long-term oncologic outcomes after neoadjuvant radiation therapy for retroperitoneal sarcomas

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.Objective: To evaluate long-term survival among patients undergoing radiation therapy (RT), followed by surgical resection of retroperitoneal sarcomas (RPS). Background: Despite a lack of level 1 evidence supporting neoadjuvant RT for RPS, its use has increased substantially over the past decade. Methods: The 1998-2011 National Cancer Data Base was queried to identify patients who underwent resection of RPS. Subjects were grouped by use of neoadjuvant RT. Perioperative variables and outcomes were compared. Multivariable logistic regression was performed to assess predictors of neoadjuvant RT. Groups were propensity matched using a 2:1 nearest neighbor algorithm and short-termoutcomeswere compared. Finally, long-termsurvivalwas evaluated using the Kaplan-Meier method,with comparisons based on the log-rank test. Results: A total of 11,324 patients were identified. Neoadjuvant RT was administered to 696 patients (6.1%). During the study period, preoperative RT use increased from 4% to nearly 15%. Male sex, tumor size larger than 5 cm, treatment at an academic/research program, and higher tumor grade all predicted neoadjuvant RT administration. After propensity matching, the only difference in baseline characteristics was the use of neoadjuvant chemotherapy. Although neoadjuvant RT was associated with a higher rate of negative margins (77.5% vs 73.0%; P = 0.014), there was no corresponding improvement in 5-year survival (53.2% vs 54.2%; P = 0.695). Conclusions: Despite the increasing use of neoadjuvant RT for patients with RPS, the survival benefit associated with this treatment modality remains unclear. Continued investigation is needed to better define the role of RT among patients with RPS.

Authors
Nussbaum, DP; Speicher, PJ; Gulack, BC; Ganapathi, AM; Englum, BR; Kirsch, DG; Tyler, DS; Blazer, DG
MLA Citation
Nussbaum, DP, Speicher, PJ, Gulack, BC, Ganapathi, AM, Englum, BR, Kirsch, DG, Tyler, DS, and Blazer, DG. "Long-term oncologic outcomes after neoadjuvant radiation therapy for retroperitoneal sarcomas." Annals of Surgery 262.1 (2015): 163-170.
Source
scival
Published In
Annals of Surgery
Volume
262
Issue
1
Publish Date
2015
Start Page
163
End Page
170
DOI
10.1097/SLA.0000000000000840

Epigenetic silencing of Kruppel like factor-3 increases expression of pro-metastatic miR-182

© 2015 Elsevier Ireland Ltd.Accumulating evidence indicates that microRNAs (miRs) regulate cancer metastasis. We have shown that miR-182 drives sarcoma metastasis in vivo by coordinated regulation of multiple genes. Recently, we also demonstrated that in a subset of primary sarcomas that metastasize to the lung, miR-182 expression is elevated through binding of MyoD1 to the miR-182 promoter. However, it is not known if there are also transcription factors that inhibit miR-182 expression. Defining negative regulators of miR-182 expression may help explain why some sarcomas do not metastasize and may also identify pathways that can modulate miR-182 for therapeutic benefit. Here, we use an in silico screen, chromatin-immunoprecipitation, and luciferase reporter assays to discover that Kruppel like factor-3 (Klf-3) is a novel transcriptional repressor of miR-182. Knockdown of Klf-3 increases miR-182 expression, and stable overexpression of Klf-3, but not a DNA-binding mutant Klf-3, decreases miR-182 levels. Klf-3 expression is downregulated in both primary mouse and human metastatic sarcomas, and Klf-3 levels negatively correlate with miR-182 expression. Interestingly, Klf-3 also negatively regulates MyoD1, suggesting an alternative mechanism for Klf-3 to repress miR-182 expression in addition to direct binding of the miR-182 promoter. Using Methylation Specific PCR (MSP) and pyrosequencing assays, we found that Klf-3 is epigenetically silenced by DNA hypermethylation both in mouse and human sarcoma cells. Finally, we show the DNA methylation inhibitor 5'Azacytidine (Aza) restores Klf-3 expression while reducing miR-182 levels. Thus, our findings suggest that demethylating agents could potentially be used to modulate miR-182 levels as a therapeutic strategy.

Authors
Sachdeva, M; Dodd, RD; Huang, Z; Grenier, C; Ma, Y; Lev, DC; Cardona, DM; Murphy, SK; Kirsch, DG
MLA Citation
Sachdeva, M, Dodd, RD, Huang, Z, Grenier, C, Ma, Y, Lev, DC, Cardona, DM, Murphy, SK, and Kirsch, DG. "Epigenetic silencing of Kruppel like factor-3 increases expression of pro-metastatic miR-182." Cancer Letters 369.1 (2015): 202-211.
Source
scival
Published In
Cancer Letters
Volume
369
Issue
1
Publish Date
2015
Start Page
202
End Page
211
DOI
10.1016/j.canlet.2015.08.016

A next-generation dual-recombinase system for time- and host-specific targeting of pancreatic cancer.

Genetically engineered mouse models (GEMMs) have dramatically improved our understanding of tumor evolution and therapeutic resistance. However, sequential genetic manipulation of gene expression and targeting of the host is almost impossible using conventional Cre-loxP-based models. We have developed an inducible dual-recombinase system by combining flippase-FRT (Flp-FRT) and Cre-loxP recombination technologies to improve GEMMs of pancreatic cancer. This enables investigation of multistep carcinogenesis, genetic manipulation of tumor subpopulations (such as cancer stem cells), selective targeting of the tumor microenvironment and genetic validation of therapeutic targets in autochthonous tumors on a genome-wide scale. As a proof of concept, we performed tumor cell-autonomous and nonautonomous targeting, recapitulated hallmarks of human multistep carcinogenesis, validated genetic therapy by 3-phosphoinositide-dependent protein kinase inactivation as well as cancer cell depletion and show that mast cells in the tumor microenvironment, which had been thought to be key oncogenic players, are dispensable for tumor formation.

Authors
Schönhuber, N; Seidler, B; Schuck, K; Veltkamp, C; Schachtler, C; Zukowska, M; Eser, S; Feyerabend, TB; Paul, MC; Eser, P; Klein, S; Lowy, AM; Banerjee, R; Yang, F; Lee, C-L; Moding, EJ; Kirsch, DG; Scheideler, A; Alessi, DR; Varela, I; Bradley, A; Kind, A; Schnieke, AE; Rodewald, H-R; Rad, R; Schmid, RM; Schneider, G; Saur, D
MLA Citation
Schönhuber, N, Seidler, B, Schuck, K, Veltkamp, C, Schachtler, C, Zukowska, M, Eser, S, Feyerabend, TB, Paul, MC, Eser, P, Klein, S, Lowy, AM, Banerjee, R, Yang, F, Lee, C-L, Moding, EJ, Kirsch, DG, Scheideler, A, Alessi, DR, Varela, I, Bradley, A, Kind, A, Schnieke, AE, Rodewald, H-R, Rad, R, Schmid, RM, Schneider, G, and Saur, D. "A next-generation dual-recombinase system for time- and host-specific targeting of pancreatic cancer." Nature medicine 20.11 (November 2014): 1340-1347.
PMID
25326799
Source
epmc
Published In
Nature Medicine
Volume
20
Issue
11
Publish Date
2014
Start Page
1340
End Page
1347
DOI
10.1038/nm.3646

Combining targeted agents with modern radiotherapy in soft tissue sarcomas.

Improved understanding of soft-tissue sarcoma (STS) biology has led to better distinction and subtyping of these diseases with the hope of exploiting the molecular characteristics of each subtype to develop appropriately targeted treatment regimens. In the care of patients with extremity STS, adjunctive radiation therapy (RT) is used to facilitate limb and function, preserving surgeries while maintaining five-year local control above 85%. In contrast, for STS originating from nonextremity anatomical sites, the rate of local recurrence is much higher (five-year local control is approximately 50%) and a major cause of death and morbidity in these patients. Incorporating novel technological advancements to administer accurate RT in combination with novel radiosensitizing agents could potentially improve local control and overall survival. RT efficacy in STS can be increased by modulating biological pathways such as angiogenesis, cell cycle regulation, cell survival signaling, and cancer-host immune interactions. Previous experiences, advancements, ongoing research, and current clinical trials combining RT with agents modulating one or more of the above pathways are reviewed. The standard clinical management of patients with STS with pretreatment biopsy, neoadjuvant treatment, and primary surgery provides an opportune disease model for interrogating translational hypotheses. The purpose of this review is to outline a strategic vision for clinical translation of preclinical findings and to identify appropriate targeted agents to combine with radiotherapy in the treatment of STS from different sites and/or different histology subtypes.

Authors
Wong, P; Houghton, P; Kirsch, DG; Finkelstein, SE; Monjazeb, AM; Xu-Welliver, M; Dicker, AP; Ahmed, M; Vikram, B; Teicher, BA; Coleman, CN; Machtay, M; Curran, WJ; Wang, D
MLA Citation
Wong, P, Houghton, P, Kirsch, DG, Finkelstein, SE, Monjazeb, AM, Xu-Welliver, M, Dicker, AP, Ahmed, M, Vikram, B, Teicher, BA, Coleman, CN, Machtay, M, Curran, WJ, and Wang, D. "Combining targeted agents with modern radiotherapy in soft tissue sarcomas." Journal of the National Cancer Institute 106.11 (November 2014). (Review)
PMID
25326640
Source
epmc
Published In
Journal of the National Cancer Institute
Volume
106
Issue
11
Publish Date
2014
DOI
10.1093/jnci/dju329

Rescuing dicer defects via inhibition of an anti-dicing nuclease.

Genetic defects in the microRNA (miRNA) generating enzyme, dicer, are increasingly linked to disease. Loss of miRNA in dicer deficiency is thought to be due to loss of miRNA-generating activity. Here, we demonstrate a catabolic mechanism driving miRNA depletion in dicer deficiency. We developed a Dicer-antagonist assay revealing a pre-miRNA degrading enzyme that competes with pre-miRNA processing. We purified this pre-miRNA degrading activity using an unbiased chromatographic procedure and identified the ribonuclease complex Translin/Trax (TN/TX). In wild-type dicer backgrounds, pre-miRNA processing was dominant. However, in dicer-deficient contexts, TN/TX broadly suppressed miRNA. These findings indicate that miRNA depletion in dicer deficiency is due to the combined loss of miRNA-generating activity and catabolic function of TN/TX. Importantly, inhibition of TN/TX mitigated loss of both miRNA and tumor suppression with dicer haploinsufficiency. These studies reveal a potentially druggable target for restoring miRNA function in cancers and emerging dicer deficiencies.

Authors
Asada, K; Canestrari, E; Fu, X; Li, Z; Makowski, E; Wu, Y-C; Mito, JK; Kirsch, DG; Baraban, J; Paroo, Z
MLA Citation
Asada, K, Canestrari, E, Fu, X, Li, Z, Makowski, E, Wu, Y-C, Mito, JK, Kirsch, DG, Baraban, J, and Paroo, Z. "Rescuing dicer defects via inhibition of an anti-dicing nuclease." Cell reports 9.4 (November 2014): 1471-1481.
PMID
25457613
Source
epmc
Published In
Cell Reports
Volume
9
Issue
4
Publish Date
2014
Start Page
1471
End Page
1481
DOI
10.1016/j.celrep.2014.10.021

MicroRNA-182 drives metastasis of primary sarcomas by targeting multiple genes.

Metastasis causes most cancer deaths, but is incompletely understood. MicroRNAs can regulate metastasis, but it is not known whether a single miRNA can regulate metastasis in primary cancer models in vivo. We compared the expression of miRNAs in metastatic and nonmetastatic primary mouse sarcomas and found that microRNA-182 (miR-182) was markedly overexpressed in some tumors that metastasized to the lungs. By utilizing genetically engineered mice with either deletion of or overexpression of miR-182 in primary sarcomas, we discovered that deletion of miR-182 substantially decreased, while overexpression of miR-182 considerably increased, the rate of lung metastasis after amputation of the tumor-bearing limb. Additionally, deletion of miR-182 decreased circulating tumor cells (CTCs), while overexpression of miR-182 increased CTCs, suggesting that miR-182 regulates intravasation of cancer cells into the circulation. We identified 4 miR-182 targets that inhibit either the migration of tumor cells or the degradation of the extracellular matrix. Notably, restoration of any of these targets in isolation did not alter the metastatic potential of sarcoma cells injected orthotopically, but the simultaneous restoration of all 4 targets together substantially decreased the number of metastases. These results demonstrate that a single miRNA can regulate metastasis of primary tumors in vivo by coordinated regulation of multiple genes.

Authors
Sachdeva, M; Mito, JK; Lee, C-L; Zhang, M; Li, Z; Dodd, RD; Cason, D; Luo, L; Ma, Y; Van Mater, D; Gladdy, R; Lev, DC; Cardona, DM; Kirsch, DG
MLA Citation
Sachdeva, M, Mito, JK, Lee, C-L, Zhang, M, Li, Z, Dodd, RD, Cason, D, Luo, L, Ma, Y, Van Mater, D, Gladdy, R, Lev, DC, Cardona, DM, and Kirsch, DG. "MicroRNA-182 drives metastasis of primary sarcomas by targeting multiple genes." The Journal of clinical investigation 124.10 (October 2014): 4305-4319.
PMID
25180607
Source
epmc
Published In
Journal of Clinical Investigation
Volume
124
Issue
10
Publish Date
2014
Start Page
4305
End Page
4319
DOI
10.1172/jci77116

Partial inhibition of gp130-Jak-Stat3 signaling prevents Wnt-β-catenin-mediated intestinal tumor growth and regeneration.

Most colon cancers arise from somatic mutations in the tumor suppressor gene APC (adenomatous polyposis coli), and these mutations cause constitutive activation of the Wnt-to-β-catenin pathway in the intestinal epithelium. Because Wnt-β-catenin signaling is required for homeostasis and regeneration of the adult intestinal epithelium, therapeutic targeting of this pathway is challenging. We found that genetic activation of the cytokine-stimulated pathway mediated by the receptor gp130, the associated Jak (Janus kinase) kinases, and the transcription factor Stat3 (signal transducer and activator of transcription 3) was required for intestinal regeneration in response to irradiation-induced damage in wild-type mice and for tumorigenesis in Apc-mutant mice. Systemic pharmacological or partial genetic inhibition of gp130-Jak-Stat3 signaling suppressed intestinal regeneration, the growth of tumors in Apc-mutant mice, and the growth of colon cancer xenografts. The growth of Apc-mutant tumors depended on gp130-Jak-Stat3 signaling for induction of the polycomb repressor Bmi-1, and the associated repression of genes encoding the cell cycle inhibitors p16 and p21. However, suppression of gp130-Jak-Stat3 signaling did not affect Wnt-β-catenin signaling or homeostasis in the intestine. Thus, these data not only suggest a molecular mechanism for how the gp130-Jak-Stat3 pathway can promote cancer but also provide a rationale for therapeutic inhibition of Jak in colon cancer.

Authors
Phesse, TJ; Buchert, M; Stuart, E; Flanagan, DJ; Faux, M; Afshar-Sterle, S; Walker, F; Zhang, H-H; Nowell, CJ; Jorissen, R; Tan, CW; Hirokawa, Y; Eissmann, MF; Poh, AR; Malaterre, J; Pearson, HB; Kirsch, DG; Provero, P; Poli, V; Ramsay, RG; Sieber, O; Burgess, AW; Huszar, D; Vincan, E; Ernst, M
MLA Citation
Phesse, TJ, Buchert, M, Stuart, E, Flanagan, DJ, Faux, M, Afshar-Sterle, S, Walker, F, Zhang, H-H, Nowell, CJ, Jorissen, R, Tan, CW, Hirokawa, Y, Eissmann, MF, Poh, AR, Malaterre, J, Pearson, HB, Kirsch, DG, Provero, P, Poli, V, Ramsay, RG, Sieber, O, Burgess, AW, Huszar, D, Vincan, E, and Ernst, M. "Partial inhibition of gp130-Jak-Stat3 signaling prevents Wnt-β-catenin-mediated intestinal tumor growth and regeneration." Science signaling 7.345 (September 30, 2014): ra92-.
PMID
25270258
Source
epmc
Published In
Science Signaling
Volume
7
Issue
345
Publish Date
2014
Start Page
ra92
DOI
10.1126/scisignal.2005411

The effect of neoadjuvant radiation therapy on perioperative outcomes among patients undergoing resection of retroperitoneal sarcomas.

Neoadjuvant radiation therapy (RT) has several theoretical benefits in the treatment of retroperitoneal sarcoma (RPS), but concerns remain about treatment toxicity and perioperative morbidity. There are limited data regarding its effect on perioperative outcomes, most of which come from small, single-institution series. The purpose of this study was to evaluate the short-term (30-day) postoperative morbidity and mortality associated with neoadjuvant RT following resection of RPS.The 2005-2011 National Surgical Quality Improvement Program Participant User File was queried for patients undergoing RPS resection. Subjects were stratified by use of neoadjuvant RT. Perioperative variables and short-term 30-day outcomes were compared. Groups were then propensity matched using a 2:1 nearest-neighbor algorithm and multivariable logistic regression was performed to assess neoadjuvant RT as a predictor of short-term 30-day outcomes.A total of 785 patients were identified. Neoadjuvant RT was administered to 71 (9.0%). Patients who received neoadjuvant RT were slightly younger (56 vs. 62 years, p < 0.001), but otherwise the groups were similar. After propensity matching, all baseline characteristics were highly similar. Median operative time was longer in the neoadjuvant RT group (279 vs. 219 min, p < 0.01), but there were no differences in mortality (1.4 vs. 2.1%, p = 0.71), major complications (28.2 vs. 25.2%, p = 0.69), overall complications (35.2 vs.33.2%, p = 0.83), early reoperation (5.6 vs. 7.4%, p = 0.81), or length of stay (7 vs. 7 days, p = 0.56). Following further adjustment with logistic regression, we confirmed that there were no differences in 30-day mortality or morbidity between patients who did and did not receive neoadjuvant RT.Neoadjuvant RT does not appear to increase short-term (30-day) morbidity or mortality following resection of RPS. Continued investigation is needed to better define the role for radiation therapy among patients with this disease.

Authors
Nussbaum, DP; Speicher, PJ; Gulack, BC; Ganapathi, AM; Keenan, JE; Stinnett, SS; Kirsch, DG; Tyler, DS; Blazer, DG
MLA Citation
Nussbaum, DP, Speicher, PJ, Gulack, BC, Ganapathi, AM, Keenan, JE, Stinnett, SS, Kirsch, DG, Tyler, DS, and Blazer, DG. "The effect of neoadjuvant radiation therapy on perioperative outcomes among patients undergoing resection of retroperitoneal sarcomas." Surgical oncology 23.3 (September 2014): 155-160. (Review)
PMID
25085344
Source
epmc
Published In
Surgical Oncology
Volume
23
Issue
3
Publish Date
2014
Start Page
155
End Page
160
DOI
10.1016/j.suronc.2014.07.001

Enhancing the efficacy of radiation therapy: premises, promises, and practicality.

Authors
Coleman, CN; Lawrence, TS; Kirsch, DG
MLA Citation
Coleman, CN, Lawrence, TS, and Kirsch, DG. "Enhancing the efficacy of radiation therapy: premises, promises, and practicality." Journal of clinical oncology : official journal of the American Society of Clinical Oncology 32.26 (September 2014): 2832-2835.
PMID
25113766
Source
epmc
Published In
Journal of Clinical Oncology
Volume
32
Issue
26
Publish Date
2014
Start Page
2832
End Page
2835
DOI
10.1200/jco.2014.57.3865

Toward a drug development path that targets metastatic progression in osteosarcoma.

Despite successful primary tumor treatment, the development of pulmonary metastasis continues to be the most common cause of mortality in patients with osteosarcoma. A conventional drug development path requiring drugs to induce regression of established lesions has not led to improvements for patients with osteosarcoma in more than 30 years. On the basis of our growing understanding of metastasis biology, it is now reasonable and essential that we focus on developing therapeutics that target metastatic progression. To advance this agenda, a meeting of key opinion leaders and experts in the metastasis and osteosarcoma communities was convened in Bethesda, Maryland. The goal of this meeting was to provide a "Perspective" that would establish a preclinical translational path that could support the early evaluation of potential therapeutic agents that uniquely target the metastatic phenotype. Although focused on osteosarcoma, the need for this perspective is shared among many cancer types. The consensus achieved from the meeting included the following: the biology of metastatic progression is associated with metastasis-specific targets/processes that may not influence grossly detectable lesions; targeting of metastasis-specific processes is feasible; rigorous preclinical data are needed to support translation of metastasis-specific agents into human trials where regression of measurable disease is not an expected outcome; preclinical data should include an understanding of mechanism of action, validation of pharmacodynamic markers of effective exposure and response, the use of several murine models of effectiveness, and where feasible the inclusion of the dog with naturally occurring osteosarcoma to define the activity of new drugs in the micrometastatic disease setting.

Authors
Khanna, C; Fan, TM; Gorlick, R; Helman, LJ; Kleinerman, ES; Adamson, PC; Houghton, PJ; Tap, WD; Welch, DR; Steeg, PS; Merlino, G; Sorensen, PHB; Meltzer, P; Kirsch, DG; Janeway, KA; Weigel, B; Randall, L; Withrow, SJ; Paoloni, M; Kaplan, R; Teicher, BA; Seibel, NL; Smith, M; Uren, A; Patel, SR; Trent, J; Savage, SA; Mirabello, L; Reinke, D; Barkaukas, DA; Krailo, M; Bernstein, M
MLA Citation
Khanna, C, Fan, TM, Gorlick, R, Helman, LJ, Kleinerman, ES, Adamson, PC, Houghton, PJ, Tap, WD, Welch, DR, Steeg, PS, Merlino, G, Sorensen, PHB, Meltzer, P, Kirsch, DG, Janeway, KA, Weigel, B, Randall, L, Withrow, SJ, Paoloni, M, Kaplan, R, Teicher, BA, Seibel, NL, Smith, M, Uren, A, Patel, SR, Trent, J, Savage, SA, Mirabello, L, Reinke, D, Barkaukas, DA, Krailo, M, and Bernstein, M. "Toward a drug development path that targets metastatic progression in osteosarcoma." Clinical cancer research : an official journal of the American Association for Cancer Research 20.16 (August 2014): 4200-4209.
PMID
24803583
Source
epmc
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
20
Issue
16
Publish Date
2014
Start Page
4200
End Page
4209
DOI
10.1158/1078-0432.ccr-13-2574

Atm deletion with dual recombinase technology preferentially radiosensitizes tumor endothelium.

Cells isolated from patients with ataxia telangiectasia are exquisitely sensitive to ionizing radiation. Kinase inhibitors of ATM, the gene mutated in ataxia telangiectasia, can sensitize tumor cells to radiation therapy, but concern that inhibiting ATM in normal tissues will also increase normal tissue toxicity from radiation has limited their clinical application. Endothelial cell damage can contribute to the development of long-term side effects after radiation therapy, but the role of endothelial cell death in tumor response to radiation therapy remains controversial. Here, we developed dual recombinase technology using both FlpO and Cre recombinases to generate primary sarcomas in mice with endothelial cell-specific deletion of Atm to determine whether loss of Atm in endothelial cells sensitizes tumors and normal tissues to radiation. Although deletion of Atm in proliferating tumor endothelial cells enhanced the response of sarcomas to radiation, Atm deletion in quiescent endothelial cells of the heart did not sensitize mice to radiation-induced myocardial necrosis. Blocking cell cycle progression reversed the effect of Atm loss on tumor endothelial cell radiosensitivity. These results indicate that endothelial cells must progress through the cell cycle in order to be radiosensitized by Atm deletion.

Authors
Moding, EJ; Lee, C-L; Castle, KD; Oh, P; Mao, L; Zha, S; Min, HD; Ma, Y; Das, S; Kirsch, DG
MLA Citation
Moding, EJ, Lee, C-L, Castle, KD, Oh, P, Mao, L, Zha, S, Min, HD, Ma, Y, Das, S, and Kirsch, DG. "Atm deletion with dual recombinase technology preferentially radiosensitizes tumor endothelium." The Journal of clinical investigation 124.8 (August 2014): 3325-3338.
PMID
25036710
Source
epmc
Published In
Journal of Clinical Investigation
Volume
124
Issue
8
Publish Date
2014
Start Page
3325
End Page
3338
DOI
10.1172/jci73932

Uveal melanoma treated with iodine-125 episcleral plaque: An analysis of dose on disease control and visual outcomes

Purpose To investigate, in the treatment of uveal melanomas, how tumor control, radiation toxicity, and visual outcomes are affected by the radiation dose at the tumor apex. Methods and Materials A retrospective review was performed to evaluate patients treated for uveal melanoma with 125 I plaques between 1988 and 2010. Radiation dose is reported as dose to tumor apex and dose to 5 mm. Primary endpoints included time to local failure, distant failure, and death. Secondary endpoints included eye preservation, visual acuity, and radiation-related complications. Univariate and multivariate analyses were performed to determine associations between radiation dose and the endpoint variables. Results One hundred ninety patients with sufficient data to evaluate the endpoints were included. The 5-year local control rate was 91%. The 5-year distant metastases rate was 10%. The 5-year overall survival rate was 84%. There were no differences in outcome (local control, distant metastases, overall survival) when dose was stratified by apex dose quartile ( < 69 Gy, 69-81 Gy, 81-89 Gy, > 89 Gy). However, increasing apex dose and dose to 5-mm depth were correlated with greater visual acuity loss (P=.02, P=.0006), worse final visual acuity (P=.02, P < .0001), and radiation complications (P < .0001, P=.0009). In addition, enucleation rates were worse with increasing quartiles of dose to 5 mm (P=.0001). Conclusions Doses at least as low as 69 Gy prescribed to the tumor apex achieve rates of local control, distant metastasis-free survival, and overall survival that are similar to radiation doses of 85 Gy to the tumor apex, but with improved visual outcomes. © 2014 Elsevier Inc. All rights reserved.

Authors
Perez, BA; Mettu, P; Vajzovic, L; Rivera, D; Alkaissi, A; Steffey, BA; Cai, J; Stinnett, S; Dutton, JJ; Buckley, EG; Halperin, E; Marks, LB; Mruthyunjaya, P; Kirsch, DG
MLA Citation
Perez, BA, Mettu, P, Vajzovic, L, Rivera, D, Alkaissi, A, Steffey, BA, Cai, J, Stinnett, S, Dutton, JJ, Buckley, EG, Halperin, E, Marks, LB, Mruthyunjaya, P, and Kirsch, DG. "Uveal melanoma treated with iodine-125 episcleral plaque: An analysis of dose on disease control and visual outcomes." International Journal of Radiation Oncology Biology Physics 89.1 (May 1, 2014): 127-136.
Source
scopus
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
89
Issue
1
Publish Date
2014
Start Page
127
End Page
136
DOI
10.1016/j.ijrobp.2014.01.026

Uveal melanoma treated with iodine-125 episcleral plaque: an analysis of dose on disease control and visual outcomes.

To investigate, in the treatment of uveal melanomas, how tumor control, radiation toxicity, and visual outcomes are affected by the radiation dose at the tumor apex.A retrospective review was performed to evaluate patients treated for uveal melanoma with (125)I plaques between 1988 and 2010. Radiation dose is reported as dose to tumor apex and dose to 5 mm. Primary endpoints included time to local failure, distant failure, and death. Secondary endpoints included eye preservation, visual acuity, and radiation-related complications. Univariate and multivariate analyses were performed to determine associations between radiation dose and the endpoint variables.One hundred ninety patients with sufficient data to evaluate the endpoints were included. The 5-year local control rate was 91%. The 5-year distant metastases rate was 10%. The 5-year overall survival rate was 84%. There were no differences in outcome (local control, distant metastases, overall survival) when dose was stratified by apex dose quartile (<69 Gy, 69-81 Gy, 81-89 Gy, >89 Gy). However, increasing apex dose and dose to 5-mm depth were correlated with greater visual acuity loss (P=.02, P=.0006), worse final visual acuity (P=.02, P<.0001), and radiation complications (P<.0001, P=.0009). In addition, enucleation rates were worse with increasing quartiles of dose to 5 mm (P=.0001).Doses at least as low as 69 Gy prescribed to the tumor apex achieve rates of local control, distant metastasis-free survival, and overall survival that are similar to radiation doses of 85 Gy to the tumor apex, but with improved visual outcomes.

Authors
Perez, BA; Mettu, P; Vajzovic, L; Rivera, D; Alkaissi, A; Steffey, BA; Cai, J; Stinnett, S; Dutton, JJ; Buckley, EG; Halperin, E; Marks, LB; Mruthyunjaya, P; Kirsch, DG
MLA Citation
Perez, BA, Mettu, P, Vajzovic, L, Rivera, D, Alkaissi, A, Steffey, BA, Cai, J, Stinnett, S, Dutton, JJ, Buckley, EG, Halperin, E, Marks, LB, Mruthyunjaya, P, and Kirsch, DG. "Uveal melanoma treated with iodine-125 episcleral plaque: an analysis of dose on disease control and visual outcomes." International journal of radiation oncology, biology, physics 89.1 (May 2014): 127-136.
PMID
24613808
Source
epmc
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
89
Issue
1
Publish Date
2014
Start Page
127
End Page
136
DOI
10.1016/j.ijrobp.2014.01.026

Europium- and lithium-doped yttrium oxide nanocrystals that provide a linear emissive response with X-ray radiation exposure.

Eu- and Li-doped yttrium oxide nanocrystals [Y2-xO3; Eux, Liy], in which Eu and Li dopant ion concentrations were systematically varied, were developed and characterized (TEM, XRD, Raman spectroscopic, UV-excited lifetime, and ICP-AES data) in order to define the most emissive compositions under specific X-ray excitation conditions. These optimized [Y2-xO3; Eux, Liy] compositions display scintillation responses that: (i) correlate linearly with incident radiation exposure at X-ray energies spanning from 40-220 kVp, and (ii) manifest no evidence of scintillation intensity saturation at the highest evaluated radiation exposures [up to 4 Roentgen per second]. For the most emissive nanoscale scintillator composition, [Y1.9O3; Eu0.1, Li0.16], excitation energies of 40, 120, and 220 kVp were chosen to probe the dependence of the integrated emission intensity upon X-ray exposure-rate in energy regimes having different mass-attenuation coefficients and where either the photoelectric or the Compton effect governs the scintillation mechanism. These experiments demonstrate for the first time for that for comparable radiation exposures, when the scintillation mechanism is governed by the photoelectric effect and a comparably larger mass-attenuation coefficient (120 kVp excitation), greater integrated emission intensities are recorded relative to excitation energies where the Compton effect regulates scintillation (220 kVp) in nanoscale [Y2-xO3; Eux] crystals. Nanoscale [Y1.9O3; Eu0.1, Li0.16] (70 ± 20 nm) was further exploited as a detector material in a prototype fiber-optic radiation sensor. The scintillation intensity from the [Y1.9O3; Eu0.1, Li0.16]-modified, 400 μm sized optical fiber tip, recorded using a CCD-photodetector and integrated over the 605-617 nm wavelength domain, was correlated with radiation exposure using a Precision XRAD 225Cx small-animal image guided radiation therapy (IGRT) system. For both 80 and 225 kVp energies, this radiotransparent device recorded scintillation intensities that tracked linearly with total radiation exposure, highlighting its capability to provide alternately accurate dosimetry measurements for both diagnostic imaging (80 kVp) and radiation therapy treatment (225 kVp).

Authors
Stanton, IN; Belley, MD; Nguyen, G; Rodrigues, A; Li, Y; Kirsch, DG; Yoshizumi, TT; Therien, MJ
MLA Citation
Stanton, IN, Belley, MD, Nguyen, G, Rodrigues, A, Li, Y, Kirsch, DG, Yoshizumi, TT, and Therien, MJ. "Europium- and lithium-doped yttrium oxide nanocrystals that provide a linear emissive response with X-ray radiation exposure." Nanoscale 6.10 (May 2014): 5284-5288.
PMID
24696056
Source
epmc
Published In
Nanoscale
Volume
6
Issue
10
Publish Date
2014
Start Page
5284
End Page
5288
DOI
10.1039/c4nr00497c

Reining in radiation injury: HIF2α in the gut.

Deletion of prolyl hydroxylase domain proteins or overexpression of hypoxia-inducible factor 2α (HIF2α) in the gastrointestinal epithelium improves survival of mice after abdominal irradiation (Taniguchi et al., this issue).

Authors
Lee, C-L; Moding, EJ; Kirsch, DG
MLA Citation
Lee, C-L, Moding, EJ, and Kirsch, DG. "Reining in radiation injury: HIF2α in the gut." Science translational medicine 6.236 (May 2014): 236fs20-.
PMID
24828075
Source
epmc
Published In
Science Translational Medicine
Volume
6
Issue
236
Publish Date
2014
Start Page
236fs20
DOI
10.1126/scitranslmed.3009155

Inhibiting glycogen synthase kinase-3 mitigates the hematopoietic acute radiation syndrome in mice.

Exposure to a nuclear accident or radiological attack can cause death from acute radiation syndrome (ARS), which results from radiation injury to vital organs such as the hematopoietic system. However, the U.S. Food and Drug Administration (FDA) has not approved any medical countermeasures for this specific purpose. With growing concern over nuclear terrorism, there is an urgent need to develop small molecule deliverables that mitigate mortality from ARS. One emerging modulator of hematopoietic stem/progenitor cell (HSPC) activity is glycogen synthase kinase-3 (GSK-3). The inhibition of GSK-3 has been shown to augment hematopoietic repopulation in mouse models of bone marrow transplantation. In this study, we performed an in vitro screen using irradiated bone marrow mononuclear cells (BM-MNCs) to test the effects of four GSK-3 inhibitors: CHIR99021; 6-Bromoindirubin-3'-oxime (BIO); SB415286; and SB216763. This screen showed that SB216763 significantly increased the frequency of c-Kit(+) Lin(-) Sca1(+) (KLS) cells and hematopoietic colony-forming cells in irradiated BM-MNCs. Importantly, administration of a single dose of SB216763 to C57BL/6J mice by subcutaneous injection 24 h after total-body irradiation significantly improved hematopoietic recovery and mitigated hematopoietic ARS. Collectively, our results demonstrate that the GSK-3 inhibitor SB216763 is an effective medical countermeasure against acute radiation injury of the hematopoietic system.

Authors
Lee, C-L; Lento, WE; Castle, KD; Chao, NJ; Kirsch, DG
MLA Citation
Lee, C-L, Lento, WE, Castle, KD, Chao, NJ, and Kirsch, DG. "Inhibiting glycogen synthase kinase-3 mitigates the hematopoietic acute radiation syndrome in mice." Radiation research 181.5 (May 2014): 445-451.
PMID
24720754
Source
epmc
Published In
Radiation Research
Volume
181
Issue
5
Publish Date
2014
Start Page
445
End Page
451
DOI
10.1667/rr13692.1

Assessing cardiac injury in mice with dual energy-microCT, 4D-microCT, and microSPECT imaging after partial heart irradiation.

To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT).To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53(FL/+) and Tie2Cre; p53(FL/-) mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion.After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53(FL/-) mice. In Tie2Cre; p53(FL/-) mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53(FL/+) mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R(2) = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53(FL/-) mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated.Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches complementary to microSPECT for noninvasive assessment of the change in myocardial vascular permeability and cardiac function of mice in whom myocardial injury develops after PHI.

Authors
Lee, C-L; Min, H; Befera, N; Clark, D; Qi, Y; Das, S; Johnson, GA; Badea, CT; Kirsch, DG
MLA Citation
Lee, C-L, Min, H, Befera, N, Clark, D, Qi, Y, Das, S, Johnson, GA, Badea, CT, and Kirsch, DG. "Assessing cardiac injury in mice with dual energy-microCT, 4D-microCT, and microSPECT imaging after partial heart irradiation." International journal of radiation oncology, biology, physics 88.3 (March 2014): 686-693.
Website
http://hdl.handle.net/10161/12625
PMID
24521682
Source
epmc
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
88
Issue
3
Publish Date
2014
Start Page
686
End Page
693
DOI
10.1016/j.ijrobp.2013.11.238

Current status and recommendations for the future of research, teaching, and testing in the biological sciences of radiation oncology: Report of the american society for radiation oncology cancer biology/radiation biology task force, executive summary

In early 2011, a dialogue was initiated within the Board of Directors (BOD) of the American Society for Radiation Oncology (ASTRO) regarding the future of the basic sciences of the specialty, primarily focused on the current state and potential future direction of basic research within radiation oncology. After consideration of the complexity of the issues involved and the precise nature of the undertaking, in August 2011, the BOD empanelled a Cancer Biology/Radiation Biology Task Force (TF). The TF was charged with developing an accurate snapshot of the current state of basic (preclinical) research in radiation oncology from the perspective of relevance to the modern clinical practice of radiation oncology as well as the education of our trainees and attending physicians in the biological sciences. The TF was further charged with making suggestions as to critical areas of biological basic research investigation that might be most likely to maintain and build further the scientific foundation and vitality of radiation oncology as an independent and vibrant medical specialty. It was not within the scope of service of the TF to consider the quality of ongoing research efforts within the broader radiation oncology space, to presume to consider their future potential, or to discourage in any way the investigators committed to areas of interest other than those targeted. The TF charge specifically precluded consideration of research issues related to technology, physics, or clinical investigations. This document represents an Executive Summary of the Task Force report. © 2014 Elsevier Inc. All rights reserved.

Authors
Wallner, PE; Anscher, MS; Barker, CA; Bassetti, M; Bristow, RG; Cha, YI; Dicker, AP; Formenti, SC; Graves, EE; Hahn, SM; Hei, TK; Kimmelman, AC; Kirsch, DG; Kozak, KR; Lawrence, TS; Marples, B; McBride, WH; Mikkelsen, RB; Park, CC; Weidhaas, JB; Zietman, AL; Steinberg, M
MLA Citation
Wallner, PE, Anscher, MS, Barker, CA, Bassetti, M, Bristow, RG, Cha, YI, Dicker, AP, Formenti, SC, Graves, EE, Hahn, SM, Hei, TK, Kimmelman, AC, Kirsch, DG, Kozak, KR, Lawrence, TS, Marples, B, McBride, WH, Mikkelsen, RB, Park, CC, Weidhaas, JB, Zietman, AL, and Steinberg, M. "Current status and recommendations for the future of research, teaching, and testing in the biological sciences of radiation oncology: Report of the american society for radiation oncology cancer biology/radiation biology task force, executive summary." International Journal of Radiation Oncology Biology Physics 88.1 (January 1, 2014): 11-17.
Source
scopus
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
88
Issue
1
Publish Date
2014
Start Page
11
End Page
17
DOI
10.1016/j.ijrobp.2013.09.040

Dual-energy micro-CT functional imaging of primary lung cancer in mice using gold and iodine nanoparticle contrast agents: a validation study.

To provide additional functional information for tumor characterization, we investigated the use of dual-energy computed tomography for imaging murine lung tumors. Tumor blood volume and vascular permeability were quantified using gold and iodine nanoparticles. This approach was compared with a single contrast agent/single-energy CT method. Ex vivo validation studies were performed to demonstrate the accuracy of in vivo contrast agent quantification by CT.Primary lung tumors were generated in LSL-Kras(G12D); p53(FL/FL) mice. Gold nanoparticles were injected, followed by iodine nanoparticles two days later. The gold accumulated in tumors, while the iodine provided intravascular contrast. Three dual-energy CT scans were performed-two for the single contrast agent method and one for the dual contrast agent method. Gold and iodine concentrations in each scan were calculated using a dual-energy decomposition. For each method, the tumor fractional blood volume was calculated based on iodine concentration, and tumor vascular permeability was estimated based on accumulated gold concentration. For validation, the CT-derived measurements were compared with histology and inductively-coupled plasma optical emission spectroscopy measurements of gold concentrations in tissues.Dual-energy CT enabled in vivo separation of gold and iodine contrast agents and showed uptake of gold nanoparticles in the spleen, liver, and tumors. The tumor fractional blood volume measurements determined from the two imaging methods were in agreement, and a high correlation (R(2) = 0.81) was found between measured fractional blood volume and histology-derived microvascular density. Vascular permeability measurements obtained from the two imaging methods agreed well with ex vivo measurements.Dual-energy CT using two types of nanoparticles is equivalent to the single nanoparticle method, but allows for measurement of fractional blood volume and permeability with a single scan. As confirmed by ex vivo methods, CT-derived nanoparticle concentrations are accurate. This method could play an important role in lung tumor characterization by CT.

Authors
Ashton, JR; Clark, DP; Moding, EJ; Ghaghada, K; Kirsch, DG; West, JL; Badea, CT
MLA Citation
Ashton, JR, Clark, DP, Moding, EJ, Ghaghada, K, Kirsch, DG, West, JL, and Badea, CT. "Dual-energy micro-CT functional imaging of primary lung cancer in mice using gold and iodine nanoparticle contrast agents: a validation study." PloS one 9.2 (January 2014): e88129-.
Website
http://hdl.handle.net/10161/11255
PMID
24520351
Source
epmc
Published In
PloS one
Volume
9
Issue
2
Publish Date
2014
Start Page
e88129
DOI
10.1371/journal.pone.0088129

RAS and ROS in rhabdomyosarcoma.

The 5-year survival for localized rhabdomyosarcoma is over 70%, but only 30% for patients presenting with metastatic disease. In this issue of Cancer Cell, Chen and colleagues performed whole-genome and RNA sequencing on human rhabdomyosarcoma and identified RAS mutations and oxidative stress as potential therapeutic targets for high-risk embryonal rhabdomyosarcoma.

Authors
Zhang, M; Linardic, CM; Kirsch, DG
MLA Citation
Zhang, M, Linardic, CM, and Kirsch, DG. "RAS and ROS in rhabdomyosarcoma." Cancer Cell 24.6 (December 9, 2013): 689-691.
PMID
24332036
Source
pubmed
Published In
Cancer Cell
Volume
24
Issue
6
Publish Date
2013
Start Page
689
End Page
691
DOI
10.1016/j.ccr.2013.11.015

Distinct and overlapping sarcoma subtypes initiated from muscle stem and progenitor cells.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, whereas undifferentiated pleomorphic sarcoma (UPS) is one of the most common soft tissue sarcomas diagnosed in adults. To investigate the myogenic cell(s) of origin of these sarcomas, we used Pax7-CreER and MyoD-CreER mice to transform Pax7(+) and MyoD(+) myogenic progenitors by expressing oncogenic Kras(G12D) and deleting Trp53 in vivo. Pax7-CreER mice developed RMS and UPS, whereas MyoD-CreER mice developed UPS. Using gene set enrichment analysis, RMS and UPS each clustered specifically within their human counterparts. These results suggest that RMS and UPS have distinct and overlapping cells of origin within the muscle lineage. Taking them together, we have established mouse models of soft tissue sarcoma from muscle stem and progenitor cells.

Authors
Blum, JM; Añó, L; Li, Z; Van Mater, D; Bennett, BD; Sachdeva, M; Lagutina, I; Zhang, M; Mito, JK; Dodd, LG; Cardona, DM; Dodd, RD; Williams, N; Ma, Y; Lepper, C; Linardic, CM; Mukherjee, S; Grosveld, GC; Fan, C-M; Kirsch, DG
MLA Citation
Blum, JM, Añó, L, Li, Z, Van Mater, D, Bennett, BD, Sachdeva, M, Lagutina, I, Zhang, M, Mito, JK, Dodd, LG, Cardona, DM, Dodd, RD, Williams, N, Ma, Y, Lepper, C, Linardic, CM, Mukherjee, S, Grosveld, GC, Fan, C-M, and Kirsch, DG. "Distinct and overlapping sarcoma subtypes initiated from muscle stem and progenitor cells." Cell Rep 5.4 (November 27, 2013): 933-940.
PMID
24239359
Source
pubmed
Published In
Cell Reports
Volume
5
Issue
4
Publish Date
2013
Start Page
933
End Page
940
DOI
10.1016/j.celrep.2013.10.020

Optimization of illumination frequency and preclinical validation of a wide-field structured illumination microscope designed for imaging in situ tumor margins

We present a widefield structured illumination microscope for imaging surgical tumor margins in situ. The impact of frequency and turbidity on optical section thickness and SNR was characterized to determine the optimal imaging frequency. © OSA 2013.

Authors
Fu, HL; Mueller, JL; Javid, M; Kirsch, DG; Ramanujam, N; Brown, JQ
MLA Citation
Fu, HL, Mueller, JL, Javid, M, Kirsch, DG, Ramanujam, N, and Brown, JQ. "Optimization of illumination frequency and preclinical validation of a wide-field structured illumination microscope designed for imaging in situ tumor margins." CLEO: Applications and Technology, CLEO_AT 2013 (November 19, 2013).
Source
scopus
Published In
CLEO: Applications and Technology, CLEO_AT 2013
Publish Date
2013

Investigating end-to-end accuracy of image guided radiation treatment delivery using a micro-irradiator.

There is significant interest in delivering precisely targeted small-volume radiation treatments, in the pre-clinical setting, to study dose-volume relationships with tumour control and normal tissue damage. For these studies it is vital that image guidance systems and target positioning are accurately aligned (IGRT), in order to deliver dose precisely and accurately according to the treatment plan. In this work we investigate the IGRT targeting accuracy of the X-RAD 225 Cx system from Precision X-Ray using high-resolution 3D dosimetry techniques. Small cylindrical PRESAGE® dosimeters were used with optical-CT readout (DMOS) to verify the accuracy of 2.5, 1.0, and 5.0 mm X-RAD cone attachments. The dosimeters were equipped with four target points, visible on both CBCT and optical-CT, at which a 7-field coplanar treatment plan was delivered with the respective cone. Targeting accuracy (distance to agreement between the target point and delivery isocenter) and cone alignment (isocenter precision under gantry rotation) were measured using the optical-CT images. Optical-CT readout of the first 2.5 mm cone dosimeter revealed a significant targeting error of 2.1 ± 0.6 mm and a cone misalignment of 1.3 ± 0.1 mm. After the IGRT hardware and software had been recalibrated, these errors were reduced to 0.5 ± 0.1 and 0.18 ± 0.04 mm respectively, within the manufacturer specified 0.5 mm. Results from the 1.0 mm cone were 0.5 ± 0.3 mm targeting accuracy and 0.4 ± 0.1 mm cone misalignment, within the 0.5 mm specification. The results from the 5.0 mm cone were 1.0 ± 0.2 mm targeting accuracy and 0.18 ± 0.06 mm cone misalignment, outside of accuracy specifications. Quality assurance of small field IGRT targeting and delivery accuracy is a challenging task. The use of a 3D dosimetry technique, where targets are visible on both CBCT and optical-CT, enabled identification and quantification of a targeting error in 3D. After correction, the targeting accuracy of the irradiator was verified to be within 0.5 mm (or 1.0 mm for the 5.0 mm cone) and the cone alignment was verified to be within 0.2 mm (or 0.4 mm for the 1.0 mm cone). The PRESAGE®/DMOS system proved valuable for end-to-end verification of small field IGRT capabilities.

Authors
Rankine, LJ; Newton, J; Bache, ST; Das, SK; Adamovics, J; Kirsch, DG; Oldham, M
MLA Citation
Rankine, LJ, Newton, J, Bache, ST, Das, SK, Adamovics, J, Kirsch, DG, and Oldham, M. "Investigating end-to-end accuracy of image guided radiation treatment delivery using a micro-irradiator." Phys Med Biol 58.21 (November 7, 2013): 7791-7801.
PMID
24140983
Source
pubmed
Published In
Physics in Medicine and Biology
Volume
58
Issue
21
Publish Date
2013
Start Page
7791
End Page
7801
DOI
10.1088/0031-9155/58/21/7791

Combining PARP-1 inhibition and radiation in Ewing sarcoma results in lethal DNA damage.

Ewing sarcomas (ES) harbor a chromosomal translocation that fuses the EWS gene to an ETS transcription factor, most commonly Friend leukemia integration 1 (FLI1). The EWS-FLI1 fusion protein acts in a positive feedback loop to maintain the expression of PARP-1, which is involved in repair of DNA damage. Here, we examine the effects of PARP-1 inhibition and radiation therapy on Ewing sarcomas. In proliferation assays, the Ewing sarcoma cell lines RD-ES and SK-N-MC were much more sensitive than non-Ewing sarcoma cell lines to the PARP-1 inhibitor olaparib (Ola; IC50 0.5-1 μmol/L vs. >5 μmol/L) and to radiation (IC50 2-4 Gy vs. >6 Gy). PARP-1 inhibition with short hairpin RNA (shRNA) or Ola sensitized Ewing sarcoma cells, but not non-Ewing sarcoma cells, to radiation therapy in both proliferation and colony formation assays. Using the Comet assay, radiation of Ewing sarcoma cells with Ola, compared to without Ola, resulted in more DNA damage at 1 hour (mean tail moment 36-54 vs. 26-28) and sustained DNA damage at 24 hours (24-29 vs. 6-8). This DNA damage led to a 2.9- to 4.0-fold increase in apoptosis and a 1.6- to 2.4-fold increase in cell death. The effect of PARP-1 inhibition and radiation therapy on Ewing sarcoma cells was lost when EWS-FLI1 was silenced by shRNA. A small dose of radiation therapy (4 Gy), when combined with PARP-1 inhibition, stopped the growth of SK-N-MC flank tumors xenografts. In conclusion, PARP-1 inhibition in Ewing sarcomas amplifies the level and duration of DNA damage caused by radiation therapy, leading to synergistic increases in apoptosis and cell death in a EWS-FLI1-dependent manner.

Authors
Lee, H-J; Yoon, C; Schmidt, B; Park, DJ; Zhang, AY; Erkizan, HV; Toretsky, JA; Kirsch, DG; Yoon, SS
MLA Citation
Lee, H-J, Yoon, C, Schmidt, B, Park, DJ, Zhang, AY, Erkizan, HV, Toretsky, JA, Kirsch, DG, and Yoon, SS. "Combining PARP-1 inhibition and radiation in Ewing sarcoma results in lethal DNA damage." Mol Cancer Ther 12.11 (November 2013): 2591-2600.
PMID
23966622
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
12
Issue
11
Publish Date
2013
Start Page
2591
End Page
2600
DOI
10.1158/1535-7163.MCT-13-0338

Role of p53 in regulating tissue response to radiation by mechanisms independent of apoptosis.

Radiation exposure leads to diverse outcomes in vivo across different tissues and even within the same cell lineage. The diversity of radiation response in vivo is at least partially attributable to the status of the tumor suppressor p53, a master regulator of cellular response to stress, and activation of its transcriptional targets. In certain cells, such as hematopoietic progenitors and transit amplifying cells in the gastrointestinal epithelium, activation of p53 by radiation triggers the intrinsic pathway of apoptosis. However, in many other cells, activation of p53 by radiation does not result in apoptosis, which underscores the importance of understanding the role of p53 in regulating radiation response through alternative mechanisms. In this review, we summarize recent studies using genetically engineered mice to dissect the role of p53 in 1) cells where its activation is dissociated from the intrinsic pathway of apoptosis, such as hematopoietic stem cells and vascular endothelial cells and 2) tissues where activation of the intrinsic pathway of apoptosis does not promote the acute radiation syndrome, such as the gastrointestinal epithelium. We highlight findings showing that the apoptosis-independent response of p53 to radiation in vivo can contribute to death or survival in a cell-type dependent manner, which underscores the complexity by which p53 regulates the cellular and tissue response to radiation.

Authors
Lee, C-L; Blum, JM; Kirsch, DG
MLA Citation
Lee, C-L, Blum, JM, and Kirsch, DG. "Role of p53 in regulating tissue response to radiation by mechanisms independent of apoptosis." Translational cancer research 2.5 (October 2013): 412-421.
PMID
24466508
Source
epmc
Published In
Translational cancer research
Volume
2
Issue
5
Publish Date
2013
Start Page
412
End Page
421

Hypoxia-dependent modification of collagen networks promotes sarcoma metastasis.

UNLABELLED: Intratumoral hypoxia and expression of hypoxia-inducible factor-1α (HIF-1α) correlate with metastasis and poor survival in patients with sarcoma. We show here that hypoxia controls sarcoma metastasis through a novel mechanism wherein HIF-1α enhances expression of the intracellular enzyme procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2). We show that loss of HIF-1α or PLOD2 expression disrupts collagen modification, cell migration, and pulmonary metastasis (but not primary tumor growth) in allograft and autochthonous LSL-Kras(G12D/+); Trp53(fl/fl) murine sarcoma models. Furthermore, ectopic PLOD2 expression restores migration and metastatic potential in HIF-1α-deficient tumors, and analysis of human sarcomas reveals elevated HIF1A and PLOD2 expression in metastatic primary lesions. Pharmacologic inhibition of PLOD enzymatic activity suppresses metastases. Collectively, these data indicate that HIF-1α controls sarcoma metastasis through PLOD2-dependent collagen modification and organization in primary tumors. We conclude that PLOD2 is a novel therapeutic target in sarcomas and successful inhibition of this enzyme may reduce tumor cell dissemination. SIGNIFICANCE: Undifferentiated pleomorphic sarcoma (UPS) is a commonly diagnosed and particularly aggressive sarcoma subtype in adults, which frequently and fatally metastasizes to the lung. Here, we show the potential use of a novel therapeutic target for the treatment of metastatic UPS, specifi cally the collagen-modifying enzyme PLOD2.

Authors
Eisinger-Mathason, TSK; Zhang, M; Qiu, Q; Skuli, N; Nakazawa, MS; Karakasheva, T; Mucaj, V; Shay, JES; Stangenberg, L; Sadri, N; Puré, E; Yoon, SS; Kirsch, DG; Simon, MC
MLA Citation
Eisinger-Mathason, TSK, Zhang, M, Qiu, Q, Skuli, N, Nakazawa, MS, Karakasheva, T, Mucaj, V, Shay, JES, Stangenberg, L, Sadri, N, Puré, E, Yoon, SS, Kirsch, DG, and Simon, MC. "Hypoxia-dependent modification of collagen networks promotes sarcoma metastasis." Cancer Discov 3.10 (October 2013): 1190-1205.
PMID
23906982
Source
pubmed
Published In
Cancer Discovery
Volume
3
Issue
10
Publish Date
2013
Start Page
1190
End Page
1205
DOI
10.1158/2159-8290.CD-13-0118

NF1 deletion generates multiple subtypes of soft-tissue sarcoma that respond to MEK inhibition.

Soft-tissue sarcomas are a heterogeneous group of tumors arising from connective tissue. Recently, mutations in the neurofibromin 1 (NF1) tumor suppressor gene were identified in multiple subtypes of human soft-tissue sarcomas. To study the effect of NF1 inactivation in the initiation and progression of distinct sarcoma subtypes, we have developed a novel mouse model of temporally and spatially restricted NF1-deleted sarcoma. To generate primary sarcomas, we inject adenovirus containing Cre recombinase into NF1(flox/flox); Ink4a/Arf(flox/flox) mice at two distinct orthotopic sites: intramuscularly or in the sciatic nerve. The mice develop either high-grade myogenic sarcomas or malignant peripheral nerve sheath tumor (MPNST)-like tumors, respectively. These tumors reflect the histologic properties and spectrum of sarcomas found in patients. To explore the use of this model for preclinical studies, we conducted a study of mitogen-activated protein kinase (MAPK) pathway inhibition with the MEK inhibitor PD325901. Treatment with PD325901 delays tumor growth through decreased cyclin D1 mRNA and cell proliferation. We also examined the effects of MEK inhibition on the native tumor stroma and find that PD325901 decreases VEGFα expression in tumor cells with a corresponding decrease in microvessel density. Taken together, our results use a primary tumor model to show that sarcomas can be generated by loss of NF1 and Ink4a/Arf, and that these tumors are sensitive to MEK inhibition by direct effects on tumor cells and the surrounding microenvironment. These studies suggest that MEK inhibitors should be further explored as potential sarcoma therapies in patients with tumors containing NF1 deletion.

Authors
Dodd, RD; Mito, JK; Eward, WC; Chitalia, R; Sachdeva, M; Ma, Y; Barretina, J; Dodd, L; Kirsch, DG
MLA Citation
Dodd, RD, Mito, JK, Eward, WC, Chitalia, R, Sachdeva, M, Ma, Y, Barretina, J, Dodd, L, and Kirsch, DG. "NF1 deletion generates multiple subtypes of soft-tissue sarcoma that respond to MEK inhibition." Mol Cancer Ther 12.9 (September 2013): 1906-1917.
PMID
23858101
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
12
Issue
9
Publish Date
2013
Start Page
1906
End Page
1917
DOI
10.1158/1535-7163.MCT-13-0189

Practical radiation oncology for extremity sarcomas.

Soft tissue sarcomas are rare cancers. They should be managed by a multidisciplinary team with experience caring for these diverse malignancies. Local control is frequently achieved with a combination of radiation therapy and surgery. This article reviews the data supporting the role of adjuvant radiotherapy in the care of patients with soft tissue sarcoma and describes the side effects of surgery and radiation therapy. Preoperative radiation therapy increases the risk of wound complication from surgery, but has fewer long-term side effects than postoperative radiation therapy. The timing of radiation therapy can be tailored to each patient.

Authors
Larrier, NA; Kirsch, DG; Riedel, RF; Levinson, H; Eward, WC; Brigman, BE
MLA Citation
Larrier, NA, Kirsch, DG, Riedel, RF, Levinson, H, Eward, WC, and Brigman, BE. "Practical radiation oncology for extremity sarcomas." Surg Oncol Clin N Am 22.3 (July 2013): 433-443. (Review)
PMID
23622072
Source
pubmed
Published In
Surgical Oncology Clinics of North America
Volume
22
Issue
3
Publish Date
2013
Start Page
433
End Page
443
DOI
10.1016/j.soc.2013.02.004

Strategies for optimizing the response of cancer and normal tissues to radiation.

Approximately 50% of all patients with cancer receive radiation therapy at some point during the course of their treatment, and the majority of these patients are treated with curative intent. Despite recent advances in the planning of radiation treatment and the delivery of image-guided radiation therapy, acute toxicity and potential long-term side effects often limit the ability to deliver a sufficient dose of radiation to control tumours locally. In the past two decades, a better understanding of the hallmarks of cancer and the discovery of specific signalling pathways by which cells respond to radiation have provided new opportunities to design molecularly targeted therapies to increase the therapeutic window of radiation therapy. Here, we review efforts to develop approaches that could improve outcomes with radiation therapy by increasing the probability of tumour cure or by decreasing normal tissue toxicity.

Authors
Moding, EJ; Kastan, MB; Kirsch, DG
MLA Citation
Moding, EJ, Kastan, MB, and Kirsch, DG. "Strategies for optimizing the response of cancer and normal tissues to radiation." Nat Rev Drug Discov 12.7 (July 2013): 526-542. (Review)
PMID
23812271
Source
pubmed
Published In
Nature Reviews Drug Discovery
Volume
12
Issue
7
Publish Date
2013
Start Page
526
End Page
542
DOI
10.1038/nrd4003

Oncogenic NRAS, required for pathogenesis of embryonic rhabdomyosarcoma, relies upon the HMGA2-IGF2BP2 pathway.

Embryonic rhabdomyosarcoma (ERMS) is the most common soft-tissue tumor in children. Here, we report the identification of the minor groove DNA-binding factor high mobility group AT-hook 2 (HMGA2) as a driver of ERMS development. HMGA2 was highly expressed in normal myoblasts and ERMS cells, where its expression was essential to maintain cell proliferation, survival in vitro, and tumor outgrowth in vivo. Mechanistic investigations revealed that upregulation of the insulin-like growth factor (IGF) mRNA-binding protein IGF2BP2 was critical for HMGA2 action. In particular, IGF2BP2 was essential for mRNA and protein stability of NRAS, a frequently mutated gene in ERMS. shRNA-mediated attenuation of NRAS or pharmacologic inhibition of the MAP-ERK kinase (MEK)/extracellular signal-regulated kinase (ERK) effector pathway showed that NRAS and NRAS-mediated signaling was required for tumor maintenance. Taken together, these findings implicate the HMGA2-IGFBP2-NRAS signaling pathway as a critical oncogenic driver in ERMS.

Authors
Li, Z; Zhang, Y; Ramanujan, K; Ma, Y; Kirsch, DG; Glass, DJ
MLA Citation
Li, Z, Zhang, Y, Ramanujan, K, Ma, Y, Kirsch, DG, and Glass, DJ. "Oncogenic NRAS, required for pathogenesis of embryonic rhabdomyosarcoma, relies upon the HMGA2-IGF2BP2 pathway." Cancer Res 73.10 (May 15, 2013): 3041-3050.
PMID
23536553
Source
pubmed
Published In
Cancer Research
Volume
73
Issue
10
Publish Date
2013
Start Page
3041
End Page
3050
DOI
10.1158/0008-5472.CAN-12-3947

Imaging primary mouse sarcomas after radiation therapy using cathepsin-activatable fluorescent imaging agents.

PURPOSE: Cathepsin-activated fluorescent probes can detect tumors in mice and in canine patients. We previously showed that these probes can detect microscopic residual sarcoma in the tumor bed of mice during gross total resection. Many patients with soft tissue sarcoma (STS) and other tumors undergo radiation therapy (RT) before surgery. This study assesses the effect of RT on the ability of cathepsin-activated probes to differentiate between normal and cancerous tissue. METHODS AND MATERIALS: A genetically engineered mouse model of STS was used to generate primary hind limb sarcomas that were treated with hypofractionated RT. Mice were injected intravenously with cathepsin-activated fluorescent probes, and various tissues, including the tumor, were imaged using a hand-held imaging device. Resected tumor and normal muscle samples were harvested to assess cathepsin expression by Western blot. Uptake of activated probe was analyzed by flow cytometry and confocal microscopy. Parallel in vitro studies using mouse sarcoma cells were performed. RESULTS: RT of primary STS in mice and mouse sarcoma cell lines caused no change in probe activation or cathepsin protease expression. Increasing radiation dose resulted in an upward trend in probe activation. Flow cytometry and immunofluorescence showed that a substantial proportion of probe-labeled cells were CD11b-positive tumor-associated immune cells. CONCLUSIONS: In this primary murine model of STS, RT did not affect the ability of cathepsin-activated probes to differentiate between tumor and normal muscle. Cathepsin-activated probes labeled tumor cells and tumor-associated macrophages. Our results suggest that it would be feasible to include patients who have received preoperative RT in clinical studies evaluating cathepsin-activated imaging probes.

Authors
Cuneo, KC; Mito, JK; Javid, MP; Ferrer, JM; Kim, Y; Lee, WD; Bawendi, MG; Brigman, BE; Kirsch, DG
MLA Citation
Cuneo, KC, Mito, JK, Javid, MP, Ferrer, JM, Kim, Y, Lee, WD, Bawendi, MG, Brigman, BE, and Kirsch, DG. "Imaging primary mouse sarcomas after radiation therapy using cathepsin-activatable fluorescent imaging agents." Int J Radiat Oncol Biol Phys 86.1 (May 1, 2013): 136-142.
PMID
23391816
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
86
Issue
1
Publish Date
2013
Start Page
136
End Page
142
DOI
10.1016/j.ijrobp.2012.12.007

Dual-energy micro-computed tomography imaging of radiation-induced vascular changes in primary mouse sarcomas.

PURPOSE: To evaluate the effects of radiation therapy on primary tumor vasculature using dual-energy (DE) micro-computed tomography (micro-CT). METHODS AND MATERIALS: Primary sarcomas were generated with mutant Kras and p53. Unirradiated tumors were compared with tumors irradiated with 20 Gy. A liposomal-iodinated contrast agent was administered 1 day after treatment, and mice were imaged immediately after injection (day 1) and 3 days later (day 4) with DE micro-CT. CT-derived tumor sizes were used to assess tumor growth. After DE decomposition, iodine maps were used to assess tumor fractional blood volume (FBV) at day 1 and tumor vascular permeability at day 4. For comparison, tumor vascularity and vascular permeability were also evaluated histologically by use of CD31 immunofluorescence and fluorescently-labeled dextrans. RESULTS: Radiation treatment significantly decreased tumor growth from day 1 to day 4 (P<.05). There was a positive correlation between CT measurement of tumor FBV on day 1 and extravasated iodine on day 4 with microvascular density (MVD) on day 4 (R(2)=0.53) and dextran accumulation (R(2)=0.63) on day 4, respectively. Despite no change in MVD measured by histology, tumor FBV significantly increased after irradiation as measured by DE micro-CT (0.070 vs 0.091, P<.05). Both dextran and liposomal-iodine accumulation in tumors increased significantly after irradiation, with dextran fractional area increasing 5.2-fold and liposomal-iodine concentration increasing 4.0-fold. CONCLUSIONS: DE micro-CT is an effective tool for noninvasive assessment of vascular changes in primary tumors. Tumor blood volume and vascular permeability increased after a single therapeutic dose of radiation treatment.

Authors
Moding, EJ; Clark, DP; Qi, Y; Li, Y; Ma, Y; Ghaghada, K; Johnson, GA; Kirsch, DG; Badea, CT
MLA Citation
Moding, EJ, Clark, DP, Qi, Y, Li, Y, Ma, Y, Ghaghada, K, Johnson, GA, Kirsch, DG, and Badea, CT. "Dual-energy micro-computed tomography imaging of radiation-induced vascular changes in primary mouse sarcomas." Int J Radiat Oncol Biol Phys 85.5 (April 1, 2013): 1353-1359.
PMID
23122984
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
85
Issue
5
Publish Date
2013
Start Page
1353
End Page
1359
DOI
10.1016/j.ijrobp.2012.09.027

In vivo characterization of tumor vasculature using iodine and gold nanoparticles and dual energy micro-CT.

Tumor blood volume and vascular permeability are well established indicators of tumor angiogenesis and important predictors in cancer diagnosis, planning and treatment. In this work, we establish a novel preclinical imaging protocol which allows quantitative measurement of both metrics simultaneously. First, gold nanoparticles are injected and allowed to extravasate into the tumor, and then liposomal iodine nanoparticles are injected. Combining a previously optimized dual energy micro-CT scan using high-flux polychromatic x-ray sources (energies: 40 kVp, 80 kVp) with a novel post-reconstruction spectral filtration scheme, we are able to decompose the results into 3D iodine and gold maps, allowing simultaneous measurement of extravasated gold and intravascular iodine concentrations. Using a digital resolution phantom, the mean limits of detectability (mean CNR = 5) for each element are determined to be 2.3 mg mL(-1) (18 mM) for iodine and 1.0 mg mL(-1) (5.1 mM) for gold, well within the observed in vivo concentrations of each element (I: 0-24 mg mL(-1), Au: 0-9 mg mL(-1)) and a factor of 10 improvement over the limits without post-reconstruction spectral filtration. Using a calibration phantom, these limits are validated and an optimal sensitivity matrix for performing decomposition using our micro-CT system is derived. Finally, using a primary mouse model of soft-tissue sarcoma, we demonstrate the in vivo application of the protocol to measure fractional blood volume and vascular permeability over the course of five days of active tumor growth.

Authors
Clark, DP; Ghaghada, K; Moding, EJ; Kirsch, DG; Badea, CT
MLA Citation
Clark, DP, Ghaghada, K, Moding, EJ, Kirsch, DG, and Badea, CT. "In vivo characterization of tumor vasculature using iodine and gold nanoparticles and dual energy micro-CT." Phys Med Biol 58.6 (March 21, 2013): 1683-1704.
PMID
23422321
Source
pubmed
Published In
Physics in Medicine and Biology
Volume
58
Issue
6
Publish Date
2013
Start Page
1683
End Page
1704
DOI
10.1088/0031-9155/58/6/1683

A novel imaging system permits real-time in vivo tumor bed assessment after resection of naturally occurring sarcomas in dogs.

BACKGROUND: Treatment of soft tissue sarcoma (STS) includes complete tumor excision. However, in some patients, residual sarcoma cells remain in the tumor bed. We previously described a novel hand-held imaging device prototype that uses molecular imaging to detect microscopic residual cancer in mice during surgery. QUESTIONS/PURPOSES: To test this device in a clinical trial of dogs with naturally occurring sarcomas, we asked: (1) Are any adverse clinical or laboratory effects observed after intravenous administration of the fluorescent probes? (2) Do canine sarcomas exhibit fluorescence after administration of the cathepsin-activated probe? (3) Is the tumor-to-background ratio sufficient to distinguish tumor from tumor bed? And (4) can residual fluorescence be detected in the tumor bed during surgery and does this correlate with a positive margin? METHODS: We studied nine dogs undergoing treatment for 10 STS or mast cell tumors. Dogs received an intravenous injection of VM249, a fluorescent probe that becomes optically active in the presence of cathepsin proteases. After injection, tumors were removed by wide resection. The tumor bed was imaged using the novel imaging device to search for residual fluorescence. We determined correlations between tissue fluorescence and histopathology, cathepsin protease expression, and development of recurrent disease. Minimum followup was 9 months (mean, 12 months; range, 9-15 months). RESULTS: Fluorescence was apparent from all 10 tumors and ranged from 3 × 10(7) to 1 × 10(9) counts/millisecond/cm(2). During intraoperative imaging, normal skeletal muscle showed no residual fluorescence. Histopathologic assessment of surgical margins correlated with intraoperative imaging in nine of 10 cases; in the other case, there was no residual fluorescence, but tumor was found at the margin on histologic examination. No animals had recurrent disease at 9 to 15 months. CONCLUSIONS: These initial findings suggest this imaging system might be useful to intraoperatively detect residual tumor after wide resections. CLINICAL RELEVANCE: The ability to assess the tumor bed intraoperatively for residual disease has the potential to improve local control.

Authors
Eward, WC; Mito, JK; Eward, CA; Carter, JE; Ferrer, JM; Kirsch, DG; Brigman, BE
MLA Citation
Eward, WC, Mito, JK, Eward, CA, Carter, JE, Ferrer, JM, Kirsch, DG, and Brigman, BE. "A novel imaging system permits real-time in vivo tumor bed assessment after resection of naturally occurring sarcomas in dogs." Clin Orthop Relat Res 471.3 (March 2013): 834-842.
PMID
22972654
Source
pubmed
Published In
Clinical Orthopaedics and Related Research ®
Volume
471
Issue
3
Publish Date
2013
Start Page
834
End Page
842
DOI
10.1007/s11999-012-2560-8

Epidermal growth factor regulates hematopoietic regeneration after radiation injury.

The mechanisms that regulate hematopoietic stem cell (HSC) regeneration after myelosuppressive injury are not well understood. We identified epidermal growth factor (EGF) to be highly enriched in the bone marrow serum of mice bearing deletion of Bak and Bax in TIE2-expressing cells in Tie2Cre; Bak1(-/-); Bax(flox/-) mice. These mice showed radioprotection of the HSC pool and 100% survival after a lethal dose of total-body irradiation (TBI). Bone marrow HSCs from wild-type mice expressed functional EGF receptor (EGFR), and systemic administration of EGF promoted the recovery of the HSC pool in vivo and improved the survival of mice after TBI. Conversely, administration of erlotinib, an EGFR antagonist, decreased both HSC regeneration and the survival of mice after TBI. Mice with EGFR deficiency in VAV-expressing hematopoietic cells also had delayed recovery of bone marrow stem and progenitor cells after TBI. Mechanistically, EGF reduced radiation-induced apoptosis of HSCs and mediated this effect through repression of the proapoptotic protein PUMA. Our findings show that EGFR signaling regulates HSC regeneration after myelosuppressive injury.

Authors
Doan, PL; Himburg, HA; Helms, K; Russell, JL; Fixsen, E; Quarmyne, M; Harris, JR; Deoliviera, D; Sullivan, JM; Chao, NJ; Kirsch, DG; Chute, JP
MLA Citation
Doan, PL, Himburg, HA, Helms, K, Russell, JL, Fixsen, E, Quarmyne, M, Harris, JR, Deoliviera, D, Sullivan, JM, Chao, NJ, Kirsch, DG, and Chute, JP. "Epidermal growth factor regulates hematopoietic regeneration after radiation injury." Nat Med 19.3 (March 2013): 295-304.
Website
http://hdl.handle.net/10161/14156
PMID
23377280
Source
pubmed
Published In
Nature Medicine
Volume
19
Issue
3
Publish Date
2013
Start Page
295
End Page
304
DOI
10.1038/nm.3070

Tie2(+) bone marrow endothelial cells regulate hematopoietic stem cell regeneration following radiation injury.

Hematopoietic stem cells (HSCs) reside in proximity to bone marrow endothelial cells (BM ECs) and maintenance of the HSC pool is dependent upon EC-mediated c-kit signaling. Here, we used genetic models to determine whether radioprotection of BM ECs could facilitate hematopoietic regeneration following radiation-induced myelosuppression. We developed mice bearing deletion of the proapoptotic proteins, BAK and BAX, in Tie2(+) ECs and HSCs (Tie2Bak/Bax(Fl/-) mice) and compared their hematopoietic recovery following total body irradiation (TBI) with mice which retained Bax in Tie2(+) cells. Mice bearing deletion of Bak and Bax in Tie2(+) cells demonstrated protection of BM HSCs, preserved BM vasculature, and 100% survival following lethal dose TBI. In contrast, mice that retained Bax expression in Tie2(+) cells demonstrated depletion of BM HSCs, disrupted BM vasculature, and 10% survival post-TBI. In a complementary study, VEcadherinBak/Bax(Fl/-) mice, which lack Bak and Bax in VEcadherin(+) ECs, also demonstrated increased recovery of BM stem/progenitor cells following TBI compared to mice which retained Bax in VEcadherin(+) ECs. Importantly, chimeric mice that lacked Bak and Bax in HSCs but retained Bak and Bax in BM ECs displayed significantly decreased HSC content and survival following TBI compared to mice lacking Bak and Bax in both HSCs and BM ECs. These data suggest that the hematopoietic response to ionizing radiation is dependent upon HSC-autonomous responses but is regulated by BM EC-mediated mechanisms. Therefore, BM ECs may be therapeutically targeted as a means to augment hematopoietic reconstitution following myelosuppression.

Authors
Doan, PL; Russell, JL; Himburg, HA; Helms, K; Harris, JR; Lucas, J; Holshausen, KC; Meadows, SK; Daher, P; Jeffords, LB; Chao, NJ; Kirsch, DG; Chute, JP
MLA Citation
Doan, PL, Russell, JL, Himburg, HA, Helms, K, Harris, JR, Lucas, J, Holshausen, KC, Meadows, SK, Daher, P, Jeffords, LB, Chao, NJ, Kirsch, DG, and Chute, JP. "Tie2(+) bone marrow endothelial cells regulate hematopoietic stem cell regeneration following radiation injury." Stem cells (Dayton, Ohio) 31.2 (February 2013): 327-337.
PMID
23132593
Source
epmc
Published In
Stem Cells
Volume
31
Issue
2
Publish Date
2013
Start Page
327
End Page
337
DOI
10.1002/stem.1275

A comparison of radial keyhole strategies for high spatial and temporal resolution 4D contrast-enhanced MRI in small animal tumor models.

PURPOSE: Dynamic contrast-enhanced (DCE) MRI has been widely used as a quantitative imaging method for monitoring tumor response to therapy. The simultaneous challenges of increasing temporal and spatial resolution in a setting where the signal from the much smaller voxel is weaker have made this MR technique difficult to implement in small-animal imaging. Existing protocols employed in preclinical DCE-MRI acquire a limited number of slices resulting in potentially lost information in the third dimension. This study describes and compares a family of four-dimensional (3D spatial + time), projection acquisition, radial keyhole-sampling strategies that support high spatial and temporal resolution. METHODS: The 4D method is based on a RF-spoiled, steady-state, gradient-recalled sequence with minimal echo time. An interleaved 3D radial trajectory with a quasi-uniform distribution of points in k-space was used for sampling temporally resolved datasets. These volumes were reconstructed with three different k-space filters encompassing a range of possible radial keyhole strategies. The effect of k-space filtering on spatial and temporal resolution was studied in a 5 mM CuSO(4) phantom consisting of a meshgrid with 350-μm spacing and in 12 tumors from three cell lines (HT-29, LoVo, MX-1) and a primary mouse sarcoma model (three tumors∕group). The time-to-peak signal intensity was used to assess the effect of the reconstruction filters on temporal resolution. As a measure of heterogeneity in the third dimension, the authors analyzed the spatial distribution of the rate of transport (K(trans)) of the contrast agent across the endothelium barrier for several different types of tumors. RESULTS: Four-dimensional radial keyhole imaging does not degrade the system spatial resolution. Phantom studies indicate there is a maximum 40% decrease in signal-to-noise ratio as compared to a fully sampled dataset. T1 measurements obtained with the interleaved radial technique do not differ significantly from those made with a conventional Cartesian spin-echo sequence. A bin-by-bin comparison of the distribution of the time-to-peak parameter shows that 4D radial keyhole reconstruction does not cause significant temporal blurring when a temporal resolution of 9.9 s is used for the subsamples of the keyhole data. In vivo studies reveal substantial tumor heterogeneity in the third spatial dimension that may be missed with lower resolution imaging protocols. CONCLUSIONS: Volumetric keyhole imaging with projection acquisition provides a means to increase spatiotemporal resolution and coverage over that provided by existing 2D Cartesian protocols. Furthermore, there is no difference in temporal resolution between the higher spatial resolution keyhole reconstruction and the undersampled projection data. The technique allows one to measure complex heterogeneity of kinetic parameters with isotropic, microscopic spatial resolution.

Authors
Subashi, E; Moding, EJ; Cofer, GP; MacFall, JR; Kirsch, DG; Qi, Y; Johnson, GA
MLA Citation
Subashi, E, Moding, EJ, Cofer, GP, MacFall, JR, Kirsch, DG, Qi, Y, and Johnson, GA. "A comparison of radial keyhole strategies for high spatial and temporal resolution 4D contrast-enhanced MRI in small animal tumor models." Med Phys 40.2 (February 2013): 022304-.
PMID
23387766
Source
pubmed
Volume
40
Issue
2
Publish Date
2013
Start Page
022304
DOI
10.1118/1.4774050

Optimization of illumination frequency and preclinical validation of a wide-field structured illumination microscope designed for imaging in situ tumor margins

We present a widefield structured illumination microscope for imaging surgical tumor margins in situ. The impact of frequency and turbidity on optical section thickness and SNR was characterized to determine the optimal imaging frequency. © 2013 The Optical Society.

Authors
Fu, HL; Mueller, JL; Javid, M; Kirsch, DG; Ramanujam, N; Brown, JQ
MLA Citation
Fu, HL, Mueller, JL, Javid, M, Kirsch, DG, Ramanujam, N, and Brown, JQ. "Optimization of illumination frequency and preclinical validation of a wide-field structured illumination microscope designed for imaging in situ tumor margins." 2013 Conference on Lasers and Electro-Optics, CLEO 2013 (January 1, 2013).
Source
scopus
Published In
2013 Conference on Lasers and Electro-Optics, CLEO 2013
Publish Date
2013

Oncogene-dependent control of miRNA biogenesis and metastatic progression in a model of undifferentiated pleomorphic sarcoma.

Undifferentiated pleomorphic sarcoma (UPS) is one of the most common soft tissue malignancies. Patients with large, high-grade sarcomas often develop fatal lung metastases. Understanding the mechanisms underlying sarcoma metastasis is needed to improve treatment of these patients. Micro-RNAs (miRNAs) are a class of small RNAs that post-transcriptionally regulate gene expression. Global alterations in miRNAs are frequently observed in a number of disease states including cancer. The signalling pathways that regulate miRNA biogenesis are beginning to emerge. To test the relevance of specific oncogenic mutations in miRNA biogenesis in sarcoma, we used primary soft tissue sarcomas expressing either Braf(V600E) or Kras(G12D). We found that Braf(V600E) mutant tumours, which have increased MAPK signalling, have higher levels of mature miRNAs and enhanced miRNA processing. To investigate the relevance of oncogene-dependent alterations in miRNA biogenesis, we introduced conditional mutations in Dicer and showed that Dicer haploinsufficiency promotes the development of distant metastases in an oncogene-dependent manner. These results demonstrate that a specific oncogenic mutation can cooperate with mutation in Dicer to promote tumour progression in vivo.

Authors
Mito, JK; Min, HD; Ma, Y; Carter, JE; Brigman, BE; Dodd, L; Dankort, D; McMahon, M; Kirsch, DG
MLA Citation
Mito, JK, Min, HD, Ma, Y, Carter, JE, Brigman, BE, Dodd, L, Dankort, D, McMahon, M, and Kirsch, DG. "Oncogene-dependent control of miRNA biogenesis and metastatic progression in a model of undifferentiated pleomorphic sarcoma." J Pathol 229.1 (January 2013): 132-140.
PMID
22951975
Source
pubmed
Published In
The Journal of Pathology
Volume
229
Issue
1
Publish Date
2013
Start Page
132
End Page
140
DOI
10.1002/path.4099

How accurate is image guided radiation therapy (IGRT) delivered with a micro-irradiator?

There is significant interest in delivering precisely targeted small-volume radiation treatments, in the pre-clinical setting, to study dose-volume relationships with tumor control and normal tissue damage. In this work we investigate the IGRT targeting accuracy of the XRad225Cx system from Precision x-Ray using high resolution 3D dosimetry techniques. Initial results revealed a significant targeting error of about 2.4mm. This error was reduced to within 0.5mm after the IGRT hardware and software had been recalibrated. The facility for 3D dosimetry was essential to gain a comprehensive understanding of the targeting error in 3D.

Authors
Oldham, M; Newton, J; Rankine, L; Adamovics, J; Kirsch, D; Das, S
MLA Citation
Oldham, M, Newton, J, Rankine, L, Adamovics, J, Kirsch, D, and Das, S. "How accurate is image guided radiation therapy (IGRT) delivered with a micro-irradiator?." January 2013.
PMID
24454521
Source
epmc
Published In
Journal of Physics
Volume
444
Publish Date
2013
Start Page
12070
DOI
10.1088/1742-6596/444/1/012070

PD-0332991, a CDK4/6 inhibitor, significantly prolongs survival in a genetically engineered mouse model of brainstem glioma.

Diffuse intrinsic pontine glioma (DIPG) is an incurable tumor that arises in the brainstem of children. To date there is not a single approved drug to effectively treat these tumors and thus novel therapies are desperately needed. Recent studies suggest that a significant fraction of these tumors contain alterations in cell cycle regulatory genes including amplification of the D-type cyclins and CDK4/6, and less commonly, loss of Ink4a-ARF leading to aberrant cell proliferation. In this study, we evaluated the therapeutic approach of targeting the cyclin-CDK-Retinoblastoma (Rb) pathway in a genetically engineered PDGF-B-driven brainstem glioma (BSG) mouse model. We found that PD-0332991 (PD), a CDK4/6 inhibitor, induces cell-cycle arrest in our PDGF-B; Ink4a-ARF deficient model both in vitro and in vivo. By contrast, the PDGF-B; p53 deficient model was mostly resistant to treatment with PD. We noted that a 7-day treatment course with PD significantly prolonged survival by 12% in the PDGF-B; Ink4a-ARF deficient BSG model. Furthermore, a single dose of 10 Gy radiation therapy (RT) followed by 7 days of treatment with PD increased the survival by 19% in comparison to RT alone. These findings provide the rationale for evaluating PD in children with Ink4a-ARF deficient gliomas.

Authors
Barton, KL; Misuraca, K; Cordero, F; Dobrikova, E; Min, HD; Gromeier, M; Kirsch, DG; Becher, OJ
MLA Citation
Barton, KL, Misuraca, K, Cordero, F, Dobrikova, E, Min, HD, Gromeier, M, Kirsch, DG, and Becher, OJ. "PD-0332991, a CDK4/6 inhibitor, significantly prolongs survival in a genetically engineered mouse model of brainstem glioma." PloS one 8.10 (January 2013): e77639-.
PMID
24098593
Source
epmc
Published In
PloS one
Volume
8
Issue
10
Publish Date
2013
Start Page
e77639
DOI
10.1371/journal.pone.0077639

Current Status and Recommendations for the Future of Research, Teaching, and Testing in the Biological Sciences of Radiation Oncology: Report of the American Society for Radiation Oncology Cancer Biology/Radiation Biology Task Force, Executive Summary

Authors
Wallner, PE; Anscher, MS; Barker, CA; Bassetti, M; Bristow, RG; Cha, YI; Dicker, AP; Formenti, SC; Graves, EE; Hahn, SM; Hei, TK; Kimmelman, AC; Kirsch, DG; Kozak, KR; Lawrence, TS; Marples, B; McBride, WH; Mikkelsen, RB; Park, CC; Weidhaas, JB; Zietman, AL; Steinberg, M
MLA Citation
Wallner, PE, Anscher, MS, Barker, CA, Bassetti, M, Bristow, RG, Cha, YI, Dicker, AP, Formenti, SC, Graves, EE, Hahn, SM, Hei, TK, Kimmelman, AC, Kirsch, DG, Kozak, KR, Lawrence, TS, Marples, B, McBride, WH, Mikkelsen, RB, Park, CC, Weidhaas, JB, Zietman, AL, and Steinberg, M. "Current Status and Recommendations for the Future of Research, Teaching, and Testing in the Biological Sciences of Radiation Oncology: Report of the American Society for Radiation Oncology Cancer Biology/Radiation Biology Task Force, Executive Summary." International Journal of Radiation Oncology, Biology, Physics (2013).
PMID
24246724
Source
scopus
Published In
International Journal of Radiation Oncology, Biology, Physics
Publish Date
2013

Assessing the radiation response of lung cancer with different gene mutations using genetically engineered mice.

PURPOSE: Non-small cell lung cancers (NSCLC) are a heterogeneous group of carcinomas harboring a variety of different gene mutations. We have utilized two distinct genetically engineered mouse models of human NSCLC (adenocarcinoma) to investigate how genetic factors within tumor parenchymal cells influence the in vivo tumor growth delay after one or two fractions of radiation therapy (RT). MATERIALS AND METHODS: Primary lung adenocarcinomas were generated in vivo in mice by intranasal delivery of an adenovirus expressing Cre-recombinase. Lung cancers expressed oncogenic Kras(G12D) and were also deficient in one of two tumor suppressor genes: p53 or Ink4a/ARF. Mice received no radiation treatment or whole lung irradiation in a single fraction (11.6 Gy) or in two 7.3 Gy fractions (14.6 Gy total) separated by 24 h. In each case, the biologically effective dose (BED) equaled 25 Gy10. Response to RT was assessed by micro-CT 2 weeks after treatment. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemical staining were performed to assess the integrity of the p53 pathway, the G1 cell-cycle checkpoint, and apoptosis. RESULTS: Tumor growth rates prior to RT were similar for the two genetic variants of lung adenocarcinoma. Lung cancers with wild-type (WT) p53 (LSL-Kras; Ink4a/ARF(FL/FL) mice) responded better to two daily fractions of 7.3 Gy compared to a single fraction of 11.6 Gy (P = 0.002). There was no statistically significant difference in the response of lung cancers deficient in p53 (LSL-Kras; p53(FL/FL) mice) to a single fraction (11.6 Gy) compared to 7.3 Gy × 2 (P = 0.23). Expression of the p53 target genes p21 and PUMA were higher and bromodeoxyuridine uptake was lower after RT in tumors with WT p53. CONCLUSION: Using an in vivo model of malignant lung cancer in mice, we demonstrate that the response of primary lung cancers to one or two fractions of RT can be influenced by specific gene mutations.

Authors
Perez, BA; Ghafoori, AP; Lee, C-L; Johnston, SM; Li, Y; Moroshek, JG; Ma, Y; Mukherjee, S; Kim, Y; Badea, CT; Kirsch, DG
MLA Citation
Perez, BA, Ghafoori, AP, Lee, C-L, Johnston, SM, Li, Y, Moroshek, JG, Ma, Y, Mukherjee, S, Kim, Y, Badea, CT, and Kirsch, DG. "Assessing the radiation response of lung cancer with different gene mutations using genetically engineered mice. (Published online)" Front Oncol 3 (2013): 72-.
PMID
23565506
Source
pubmed
Published In
Frontiers in Oncology
Volume
3
Publish Date
2013
Start Page
72
DOI
10.3389/fonc.2013.00072

Dual-energy micro-computed tomography imaging of radiation-induced vascular changes in primary mouse sarcomas

Purpose: To evaluate the effects of radiation therapy on primary tumor vasculature using dual-energy (DE) micro-computed tomography (micro-CT). Methods and Materials: Primary sarcomas were generated with mutant Kras and p53. Unirradiated tumors were compared with tumors irradiated with 20 Gy. A liposomal-iodinated contrast agent was administered 1 day after treatment, and mice were imaged immediately after injection (day 1) and 3 days later (day 4) with DE micro-CT. CT-derived tumor sizes were used to assess tumor growth. After DE decomposition, iodine maps were used to assess tumor fractional blood volume (FBV) at day 1 and tumor vascular permeability at day 4. For comparison, tumor vascularity and vascular permeability were also evaluated histologically by use of CD31 immunofluorescence and fluorescently-labeled dextrans. Results: Radiation treatment significantly decreased tumor growth from day 1 to day 4 (P<.05). There was a positive correlation between CT measurement of tumor FBV on day 1 and extravasated iodine on day 4 with microvascular density (MVD) on day 4 (R2=0.53) and dextran accumulation (R2=0.63) on day 4, respectively. Despite no change in MVD measured by histology, tumor FBV significantly increased after irradiation as measured by DE micro-CT (0.070 vs 0.091, P<.05). Both dextran and liposomal-iodine accumulation in tumors increased significantly after irradiation, with dextran fractional area increasing 5.2-fold and liposomal-iodine concentration increasing 4.0-fold. Conclusions: DE micro-CT is an effective tool for noninvasive assessment of vascular changes in primary tumors. Tumor blood volume and vascular permeability increased after a single therapeutic dose of radiation treatment. © 2013 Elsevier Inc.

Authors
Moding, EJ; Clark, DP; Qi, Y; Li, Y; Ma, Y; Ghaghada, K; Johnson, GA; Kirsch, DG; Badea, CT
MLA Citation
Moding, EJ, Clark, DP, Qi, Y, Li, Y, Ma, Y, Ghaghada, K, Johnson, GA, Kirsch, DG, and Badea, CT. "Dual-energy micro-computed tomography imaging of radiation-induced vascular changes in primary mouse sarcomas." International Journal of Radiation Oncology Biology Physics 85.5 (2013): 1353-1359.
Source
scival
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
85
Issue
5
Publish Date
2013
Start Page
1353
End Page
1359
DOI
10.1016/j.ijrobp.2012.09.027

Oncogene-dependent control of miRNA biogenesis and metastatic progression in a model of undifferentiated pleomorphic sarcoma

Undifferentiated pleomorphic sarcoma (UPS) is one of the most common soft tissue malignancies. Patients with large, high-grade sarcomas often develop fatal lung metastases. Understanding the mechanisms underlying sarcoma metastasis is needed to improve treatment of these patients. Micro-RNAs (miRNAs) are a class of small RNAs that post-transcriptionally regulate gene expression. Global alterations in miRNAs are frequently observed in a number of disease states including cancer. The signalling pathways that regulate miRNA biogenesis are beginning to emerge. To test the relevance of specific oncogenic mutations in miRNA biogenesis in sarcoma, we used primary soft tissue sarcomas expressing either BrafV600E or KrasG12D. We found that Braf V600E mutant tumours, which have increased MAPK signalling, have higher levels of mature miRNAs and enhanced miRNA processing. To investigate the relevance of oncogene-dependent alterations in miRNA biogenesis, we introduced conditional mutations in Dicer and showed that Dicer haploinsufficiency promotes the development of distant metastases in an oncogene-dependent manner. These results demonstrate that a specific oncogenic mutation can cooperate with mutation in Dicer to promote tumour progression in vivo.Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Authors
Mito, JK; Min, HD; Ma, Y; Carter, JE; Brigman, BE; Dodd, L; Dankort, D; McMahon, M; Kirsch, DG
MLA Citation
Mito, JK, Min, HD, Ma, Y, Carter, JE, Brigman, BE, Dodd, L, Dankort, D, McMahon, M, and Kirsch, DG. "Oncogene-dependent control of miRNA biogenesis and metastatic progression in a model of undifferentiated pleomorphic sarcoma." Journal of Pathology 229.1 (2013): 132-140.
Source
scival
Published In
The Journal of Pathology
Volume
229
Issue
1
Publish Date
2013
Start Page
132
End Page
140
DOI
10.1002/path.4099

An HMGA2-IGF2BP2 Axis Regulates Myoblast Proliferation and Myogenesis

Authors
Li, Z; Gilbert, JA; Zhang, Y; Zhang, M; Qiu, Q; Ramanujan, K; Shavlakadze, T; Eash, JK; Scaramozza, A; Goddeeris, MM; Kirsch, DG; Campbell, KP; Brack, AS; Glass, DJ
MLA Citation
Li, Z, Gilbert, JA, Zhang, Y, Zhang, M, Qiu, Q, Ramanujan, K, Shavlakadze, T, Eash, JK, Scaramozza, A, Goddeeris, MM, Kirsch, DG, Campbell, KP, Brack, AS, and Glass, DJ. "An HMGA2-IGF2BP2 Axis Regulates Myoblast Proliferation and Myogenesis." Developmental Cell 24.1 (2013): 112--.
Source
scival
Published In
Developmental Cell
Volume
24
Issue
1
Publish Date
2013
Start Page
112-
DOI
10.1016/j.devcel.2012.12.007

Agreement Among RTOG Sarcoma Radiation Oncologists in Contouring Suspicious Peritumoral Edema for Preoperative Radiation Therapy of Soft Tissue Sarcoma of the Extremity

Purpose: Peritumoral edema may harbor sarcoma cells. The extent of suspicious edema (SE) included in the treatment volume is subject to clinical judgment, balancing the risk of missing tumor cells with excess toxicity. Our goal was to determine variability in SE delineation by sarcoma radiation oncologists (RO). Methods and Materials: Twelve expert ROs were provided with T1 gadolinium and T2-weighted MR images of 10 patients with high-grade extremity soft-tissue sarcoma. Gross tumor volume, clinical target volume (CTV)3cm (3 cm longitudinal and 1.5 cm radial margin), and CTV2cm (2 cm longitudinal and 1 cm radial margin) were contoured by a single observer. Suspicious peritumoral edema, defined as abnormal signal on T2 images, was independently delineated by all 12 ROs. Contouring agreement was analyzed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results: The mean volumes of GTV, CTV2cm, and CTV3cm were, respectively, 130 cm3 (7-413 cm3), 280 cm3 and 360 cm3. The mean consensus volume computed using the STAPLE algorithm at 95% confidence interval was 188 cm3 (24-565 cm3) with a substantial overall agreement corrected for chance (mean kappa = 0.71; range: 0.32-0.87). The minimum, maximum, and mean volume of SE (excluding the GTV) were 4, 182, and 58 cm3 (representing a median of 29% of the GTV volume). The median volume of SE not included in the CTV2cm and in the CTV3cm was 5 and 0.3 cm3, respectively. There were 3 large tumors with >30 cm3 of SE not included in the CTV3cm volume. Conclusion: Despite the fact that SE would empirically seem to be a more subjective volume, a substantial or near-perfect interobserver agreement was observed in SE delineation in most cases with high-grade soft-tissue sarcomas of the extremity. A median of 97% of the consensus SE is within the CTV2cm (99.8% within the CTV3cm). In a minority of cases, however, significant expansion of the CTVs is required to cover SE. © 2013 Elsevier Inc. All rights reserved.

Authors
Bahig, H; Roberge, D; Bosch, W; Levin, W; Petersen, I; Haddock, M; Freeman, C; DeLaney, TF; Abrams, RA; Indelicato, DJ; al, E
MLA Citation
Bahig, H, Roberge, D, Bosch, W, Levin, W, Petersen, I, Haddock, M, Freeman, C, DeLaney, TF, Abrams, RA, Indelicato, DJ, and al, E. "Agreement Among RTOG Sarcoma Radiation Oncologists in Contouring Suspicious Peritumoral Edema for Preoperative Radiation Therapy of Soft Tissue Sarcoma of the Extremity." International Journal of Radiation Oncology, Biology, Physics (2013).
PMID
23474110
Source
scival
Published In
International Journal of Radiation Oncology, Biology, Physics
Publish Date
2013
DOI
10.1016/j.ijrobp.2013.01.032

A novel imaging system permits real-time in vivo tumor bed assessment after resection of naturally occurring sarcomas in dogs tumor

Background: Treatment of soft tissue sarcoma (STS) includes complete tumor excision. However, in some patients, residual sarcoma cells remain in the tumor bed. We previously described a novel hand-held imaging device prototype that uses molecular imaging to detect microscopic residual cancer in mice during surgery. Questions/purposes: To test this device in a clinical trial of dogs with naturally occurring sarcomas, we asked: (1) Are any adverse clinical or laboratory effects observed after intravenous administration of the fluorescent probes? (2) Do canine sarcomas exhibit fluorescence after administration of the cathepsin-activated probe? (3) Is the tumor-to-background ratio sufficient to distinguish tumor from tumor bed? And (4) can residual fluorescence be detected in the tumor bed during surgery and does this correlate with a positive margin? Methods: We studied nine dogs undergoing treatment for 10 STS or mast cell tumors. Dogs received an intravenous injection of VM249, a fluorescent probe that becomes optically active in the presence of cathepsin proteases. After injection, tumors were removed by wide resection. The tumor bed was imaged using the novel imaging device to search for residual fluorescence. We determined correlations between tissue fluorescence and histopathology, cathepsin protease expression, and development of recurrent disease. Minimum followup was 9 months (mean, 12 months; range, 9-15 months). Results: Fluorescence was apparent from all 10 tumors and ranged from 3 × 107 to 1 × 10 9 counts/millisecond/cm2. During intraoperative imaging, normal skeletal muscle showed no residual fluorescence. Histopathologic assessment of surgical margins correlated with intraoperative imaging in nine of 10 cases; in the other case, there was no residual fluorescence, but tumor was found at the margin on histologic examination. No animals had recurrent disease at 9 to 15 months. Conclusions: These initial findings suggest this imaging system might be useful to intraoperatively detect residual tumor after wide resections. Clinical Relevance: The ability to assess the tumor bed intraoperatively for residual disease has the potential to improve local control. © 2012 The Association of Bone and Joint Surgeons®.

Authors
Eward, WC; Mito, JK; Eward, CA; Carter, JE; Ferrer, JM; Kirsch, DG; Brigman, BE
MLA Citation
Eward, WC, Mito, JK, Eward, CA, Carter, JE, Ferrer, JM, Kirsch, DG, and Brigman, BE. "A novel imaging system permits real-time in vivo tumor bed assessment after resection of naturally occurring sarcomas in dogs tumor." Clinical Orthopaedics and Related Research 471.3 (2013): 834-842.
Source
scival
Published In
Clinical Orthopaedics and Related Research ®
Volume
471
Issue
3
Publish Date
2013
Start Page
834
End Page
842
DOI
10.1007/s11999-012-2560-8

Imaging primary mouse sarcomas after radiation therapy using cathepsin-activatable fluorescent imaging agents

Purpose: Cathepsin-activated fluorescent probes can detect tumors in mice and in canine patients. We previously showed that these probes can detect microscopic residual sarcoma in the tumor bed of mice during gross total resection. Many patients with soft tissue sarcoma (STS) and other tumors undergo radiation therapy (RT) before surgery. This study assesses the effect of RT on the ability of cathepsin-activated probes to differentiate between normal and cancerous tissue. Methods and Materials: A genetically engineered mouse model of STS was used to generate primary hind limb sarcomas that were treated with hypofractionated RT. Mice were injected intravenously with cathepsin-activated fluorescent probes, and various tissues, including the tumor, were imaged using a hand-held imaging device. Resected tumor and normal muscle samples were harvested to assess cathepsin expression by Western blot. Uptake of activated probe was analyzed by flow cytometry and confocal microscopy. Parallel in vitro studies using mouse sarcoma cells were performed. Results: RT of primary STS in mice and mouse sarcoma cell lines caused no change in probe activation or cathepsin protease expression. Increasing radiation dose resulted in an upward trend in probe activation. Flow cytometry and immunofluorescence showed that a substantial proportion of probe-labeled cells were CD11b-positive tumor-associated immune cells. Conclusions: In this primary murine model of STS, RT did not affect the ability of cathepsin-activated probes to differentiate between tumor and normal muscle. Cathepsin-activated probes labeled tumor cells and tumor-associated macrophages. Our results suggest that it would be feasible to include patients who have received preoperative RT in clinical studies evaluating cathepsin-activated imaging probes. © 2013 Elsevier Inc. All rights reserved.

Authors
Cuneo, KC; Mito, JK; Javid, MP; Ferrer, JM; Kim, Y; Lee, WD; Bawendi, MG; Brigman, BE; Kirsch, DG
MLA Citation
Cuneo, KC, Mito, JK, Javid, MP, Ferrer, JM, Kim, Y, Lee, WD, Bawendi, MG, Brigman, BE, and Kirsch, DG. "Imaging primary mouse sarcomas after radiation therapy using cathepsin-activatable fluorescent imaging agents." International Journal of Radiation Oncology Biology Physics 86.1 (2013): 136-142.
Source
scival
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
86
Issue
1
Publish Date
2013
Start Page
136
End Page
142
DOI
10.1016/j.ijrobp.2012.12.007

Quantitative segmentation of fluorescence microscopy images of heterogeneous tissue: Approach for tuning algorithm parameters

The combination of fluorescent contrast agents with microscopy is a powerful technique to obtain real time images of tissue histology without the need for fixing, sectioning, and staining. The potential of this technology lies in the identification of robust methods for image segmentation and quantitation, particularly in heterogeneous tissues. Our solution is to apply sparse decomposition (SD) to monochrome images of fluorescently-stained microanatomy to segment and quantify distinct tissue types. The clinical utility of our approach is demonstrated by imaging excised margins in a cohort of mice after surgical resection of a sarcoma. Representative images of excised margins were used to optimize the formulation of SD and tune parameters associated with the algorithm. Our results demonstrate that SD is a robust solution that can advance vital fluorescence microscopy as a clinically significant technology. © 2013 Copyright SPIE.

Authors
Mueller, JL; Harmany, ZT; Mito, JK; Kennedy, SA; Kim, Y; Dodd, L; Geradts, J; Kirsch, DG; Willett, RM; Brown, JQ; Ramanujam, N
MLA Citation
Mueller, JL, Harmany, ZT, Mito, JK, Kennedy, SA, Kim, Y, Dodd, L, Geradts, J, Kirsch, DG, Willett, RM, Brown, JQ, and Ramanujam, N. "Quantitative segmentation of fluorescence microscopy images of heterogeneous tissue: Approach for tuning algorithm parameters." Progress in Biomedical Optics and Imaging - Proceedings of SPIE 8587 (2013).
Source
scival
Published In
Proceedings of SPIE
Volume
8587
Publish Date
2013
DOI
10.1117/12.2006429

Agreement among RTOG sarcoma radiation oncologists in contouring suspicious peritumoral edema for preoperative radiation therapy of soft tissue sarcoma of the extremity

Purpose: Peritumoral edema may harbor sarcoma cells. The extent of suspicious edema (SE) included in the treatment volume is subject to clinical judgment, balancing the risk of missing tumor cells with excess toxicity. Our goal was to determine variability in SE delineation by sarcoma radiation oncologists (RO). Methods and Materials: Twelve expert ROs were provided with T1 gadolinium and T2-weighted MR images of 10 patients with high-grade extremity soft-tissue sarcoma. Gross tumor volume, clinical target volume (CTV)3cm (3 cm longitudinal and 1.5 cm radial margin), and CTV2cm (2 cm longitudinal and 1 cm radial margin) were contoured by a single observer. Suspicious peritumoral edema, defined as abnormal signal on T2 images, was independently delineated by all 12 ROs. Contouring agreement was analyzed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results: The mean volumes of GTV, CTV2cm, and CTV3cm were, respectively, 130 cm 3 (7-413 cm3), 280 cm3 and 360 cm3. The mean consensus volume computed using the STAPLE algorithm at 95% confidence interval was 188 cm3 (24-565 cm3) with a substantial overall agreement corrected for chance (mean kappa = 0.71; range: 0.32-0.87). The minimum, maximum, and mean volume of SE (excluding the GTV) were 4, 182, and 58 cm3 (representing a median of 29% of the GTV volume). The median volume of SE not included in the CTV2cm and in the CTV3cm was 5 and 0.3 cm 3, respectively. There were 3 large tumors with >30 cm3 of SE not included in the CTV3cm volume. Conclusion: Despite the fact that SE would empirically seem to be a more subjective volume, a substantial or near-perfect interobserver agreement was observed in SE delineation in most cases with high-grade soft-tissue sarcomas of the extremity. A median of 97% of the consensus SE is within the CTV2cm (99.8% within the CTV3cm). In a minority of cases, however, significant expansion of the CTVs is required to cover SE. © 2013 Elsevier Inc. All rights reserved.

Authors
Bahig, H; Roberge, D; Bosch, W; Levin, W; Petersen, I; Haddock, M; Freeman, C; Delaney, TF; Abrams, RA; Indelicato, DJ; Baldini, EH; Hitchcock, Y; Kirsch, DG; Kozak, KR; Wolfson, A; Wang, D
MLA Citation
Bahig, H, Roberge, D, Bosch, W, Levin, W, Petersen, I, Haddock, M, Freeman, C, Delaney, TF, Abrams, RA, Indelicato, DJ, Baldini, EH, Hitchcock, Y, Kirsch, DG, Kozak, KR, Wolfson, A, and Wang, D. "Agreement among RTOG sarcoma radiation oncologists in contouring suspicious peritumoral edema for preoperative radiation therapy of soft tissue sarcoma of the extremity." International Journal of Radiation Oncology Biology Physics 86.2 (2013): 298-303.
Source
scival
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
86
Issue
2
Publish Date
2013
Start Page
298
End Page
303
DOI
10.1016/j.ijrobp.2013.01.032

Quantitative Segmentation of Fluorescence Microscopy Images of Heterogeneous Tissue: Application to the Detection of Residual Disease in Tumor Margins.

PURPOSE: To develop a robust tool for quantitative in situ pathology that allows visualization of heterogeneous tissue morphology and segmentation and quantification of image features. MATERIALS AND METHODS: TISSUE EXCISED FROM A GENETICALLY ENGINEERED MOUSE MODEL OF SARCOMA WAS IMAGED USING A SUBCELLULAR RESOLUTION MICROENDOSCOPE AFTER TOPICAL APPLICATION OF A FLUORESCENT ANATOMICAL CONTRAST AGENT: acriflavine. An algorithm based on sparse component analysis (SCA) and the circle transform (CT) was developed for image segmentation and quantification of distinct tissue types. The accuracy of our approach was quantified through simulations of tumor and muscle images. Specifically, tumor, muscle, and tumor+muscle tissue images were simulated because these tissue types were most commonly observed in sarcoma margins. Simulations were based on tissue characteristics observed in pathology slides. The potential clinical utility of our approach was evaluated by imaging excised margins and the tumor bed in a cohort of mice after surgical resection of sarcoma. RESULTS: Simulation experiments revealed that SCA+CT achieved the lowest errors for larger nuclear sizes and for higher contrast ratios (nuclei intensity/background intensity). For imaging of tumor margins, SCA+CT effectively isolated nuclei from tumor, muscle, adipose, and tumor+muscle tissue types. Differences in density were correctly identified with SCA+CT in a cohort of ex vivo and in vivo images, thus illustrating the diagnostic potential of our approach. CONCLUSION: The combination of a subcellular-resolution microendoscope, acriflavine staining, and SCA+CT can be used to accurately isolate nuclei and quantify their density in anatomical images of heterogeneous tissue.

Authors
Mueller, JL; Harmany, ZT; Mito, JK; Kennedy, SA; Kim, Y; Dodd, L; Geradts, J; Kirsch, DG; Willett, RM; Brown, JQ; Ramanujam, N
MLA Citation
Mueller, JL, Harmany, ZT, Mito, JK, Kennedy, SA, Kim, Y, Dodd, L, Geradts, J, Kirsch, DG, Willett, RM, Brown, JQ, and Ramanujam, N. "Quantitative Segmentation of Fluorescence Microscopy Images of Heterogeneous Tissue: Application to the Detection of Residual Disease in Tumor Margins. (Published online)" PLoS One 8.6 (2013): e66198-.
PMID
23824589
Source
pubmed
Published In
PloS one
Volume
8
Issue
6
Publish Date
2013
Start Page
e66198
DOI
10.1371/journal.pone.0066198

Optimization of a widefield structured illumination microscope for non-destructive assessment and quantification of nuclear features in tumor margins of a primary mouse model of sarcoma.

Cancer is associated with specific cellular morphological changes, such as increased nuclear size and crowding from rapidly proliferating cells. In situ tissue imaging using fluorescent stains may be useful for intraoperative detection of residual cancer in surgical tumor margins. We developed a widefield fluorescence structured illumination microscope (SIM) system with a single-shot FOV of 2.1 × 1.6 mm (3.4 mm(2)) and sub-cellular resolution (4.4 µm). The objectives of this work were to measure the relationship between illumination pattern frequency and optical sectioning strength and signal-to-noise ratio in turbid (i.e. thick) samples for selection of the optimum frequency, and to determine feasibility for detecting residual cancer on tumor resection margins, using a genetically engineered primary mouse model of sarcoma. The SIM system was tested in tissue mimicking solid phantoms with various scattering levels to determine impact of both turbidity and illumination frequency on two SIM metrics, optical section thickness and modulation depth. To demonstrate preclinical feasibility, ex vivo 50 µm frozen sections and fresh intact thick tissue samples excised from a primary mouse model of sarcoma were stained with acridine orange, which stains cell nuclei, skeletal muscle, and collagenous stroma. The cell nuclei were segmented using a high-pass filter algorithm, which allowed quantification of nuclear density. The results showed that the optimal illumination frequency was 31.7 µm(-1) used in conjunction with a 4 × 0.1 NA objective (v=0.165). This yielded an optical section thickness of 128 µm and an 8.9 × contrast enhancement over uniform illumination. We successfully demonstrated the ability to resolve cell nuclei in situ achieved via SIM, which allowed segmentation of nuclei from heterogeneous tissues in the presence of considerable background fluorescence. Specifically, we demonstrate that optical sectioning of fresh intact thick tissues performed equivalently in regards to nuclear density quantification, to physical frozen sectioning and standard microscopy.

Authors
Fu, HL; Mueller, JL; Javid, MP; Mito, JK; Kirsch, DG; Ramanujam, N; Brown, JQ
MLA Citation
Fu, HL, Mueller, JL, Javid, MP, Mito, JK, Kirsch, DG, Ramanujam, N, and Brown, JQ. "Optimization of a widefield structured illumination microscope for non-destructive assessment and quantification of nuclear features in tumor margins of a primary mouse model of sarcoma. (Published online)" PLoS One 8.7 (2013): e68868-.
PMID
23894357
Source
pubmed
Published In
PloS one
Volume
8
Issue
7
Publish Date
2013
Start Page
e68868
DOI
10.1371/journal.pone.0068868

Definitive high-dose photon/proton radiotherapy for unresected mobile spine and sacral chordomas

Study Design.: A retrospective review. Objective.: The purpose of this study is to report the results of high-dose proton based definitive radiotherapy for unresected spinal chordomas. Summary of Background Data.: Spine chordoma is treated primarily by surgical resection. However, local recurrence rate is high. Adjuvant radiotherapy improves local control. In certain locations, such as high sacrum, resection may result in significant neurological dysfunction. Methods.: We retrospectively reviewed 24 patients with newly diagnosed, previously untreated spinal chordomas (core biopsy only; no prior incision or resection) treated with high-dose definitive radiotherapy alone using protons and photons at our center from 1988 to 2009. Results.: Reasons for radiotherapy alone included medical inoperability (3) and concern for neurological dysfunction based on spine level (21). Median age was 69.5 years. Tumor locations included cervical (2), thoracic (1), lumbar (2), S1-S2 (17), and S3 or below (2). Median maximal tumor diameter was 6.6 cm (1.4-25.5), and median tumor volume was 198.3 cm (4.65-2061). Median total dose was 77.4 GyRBE (proton dose unit, gray relative biological effectiveness). Analysis at median follow-up of 56 months showed overall survival of 91.7% and 78.1%, chordoma specific survival of 95.7% and 81.5%, local progression free survival of 90.4% and 79.8% and metastases free survival of 86.5% and 76.3%, at 3 and 5 years respectively. Tumor volume more than 500 cm was correlated with worse overall survival. Long-term side effects included 8 sacral insufficiency fractures (none required surgical stabilization), 1 secondary malignancy, 1 foot drop, 1 erectile dysfunction, 1 perineal numbness, 2 worsening urinary/fecal incontinence, and 4 grade-2 rectal bleeding. None required new colostomy. All surviving patients remained ambulatory. Conclusion.: These results support the use of high-dose definitive radiotherapy for patients with medically inoperable or otherwise unresected, mobile spine or sacrococcygeal chordomas. Copyright © 2013 Lippincott Williams & Wilkins.

Authors
Chen, Y-L; Liebsch, N; Kobayashi, W; Goldberg, S; Kirsch, D; Calkins, G; Childs, S; Schwab, J; Hornicek, F; Delaney, T
MLA Citation
Chen, Y-L, Liebsch, N, Kobayashi, W, Goldberg, S, Kirsch, D, Calkins, G, Childs, S, Schwab, J, Hornicek, F, and Delaney, T. "Definitive high-dose photon/proton radiotherapy for unresected mobile spine and sacral chordomas." Spine 38.15 (2013): E930-E936.
PMID
23609202
Source
scival
Published In
Spine
Volume
38
Issue
15
Publish Date
2013
Start Page
E930
End Page
E936
DOI
10.1097/BRS.0b013e318296e7d7

An HMGA2-IGF2BP2 Axis Regulates Myoblast Proliferation and Myogenesis

Authors
Li, Z; Gilbert, JA; Zhang, Y; Zhang, M; Qiu, Q; Ramanujan, K; Shavlakadze, T; Eash, JK; Scaramozza, A; Goddeeris, MM; Kirsch, DG; Campbell, KP; Brack, AS; Glass, DJ
MLA Citation
Li, Z, Gilbert, JA, Zhang, Y, Zhang, M, Qiu, Q, Ramanujan, K, Shavlakadze, T, Eash, JK, Scaramozza, A, Goddeeris, MM, Kirsch, DG, Campbell, KP, Brack, AS, and Glass, DJ. "An HMGA2-IGF2BP2 Axis Regulates Myoblast Proliferation and Myogenesis." DEVELOPMENTAL CELL 23.6 (December 11, 2012): 1176-1188.
PMID
23177649
Source
wos-lite
Published In
Developmental Cell
Volume
23
Issue
6
Publish Date
2012
Start Page
1176
End Page
1188
DOI
10.1016/j.devcel.2012.10.019

Intraoperative detection and removal of microscopic residual sarcoma using wide-field imaging.

BACKGROUND: The goal of limb-sparing surgery for a soft tissue sarcoma of the extremity is to remove all malignant cells while preserving limb function. After initial surgery, microscopic residual disease in the tumor bed will cause a local recurrence in approximately 33% of patients with sarcoma. To help identify these patients, the authors developed an in vivo imaging system to investigate the suitability of molecular imaging for intraoperative visualization. METHODS: A primary mouse model of soft tissue sarcoma and a wide field-of-view imaging device were used to investigate a series of exogenously administered, near-infrared (NIR) fluorescent probes activated by cathepsin proteases for real-time intraoperative imaging. RESULTS: The authors demonstrated that exogenously administered cathepsin-activated probes can be used for image-guided surgery to identify microscopic residual NIR fluorescence in the tumor beds of mice. The presence of residual NIR fluorescence was correlated with microscopic residual sarcoma and local recurrence. The removal of residual NIR fluorescence improved local control. CONCLUSIONS: The authors concluded that their technique has the potential to be used for intraoperative image-guided surgery to identify microscopic residual disease in patients with cancer.

Authors
Mito, JK; Ferrer, JM; Brigman, BE; Lee, C-L; Dodd, RD; Eward, WC; Marshall, LF; Cuneo, KC; Carter, JE; Ramasunder, S; Kim, Y; Lee, WD; Griffith, LG; Bawendi, MG; Kirsch, DG
MLA Citation
Mito, JK, Ferrer, JM, Brigman, BE, Lee, C-L, Dodd, RD, Eward, WC, Marshall, LF, Cuneo, KC, Carter, JE, Ramasunder, S, Kim, Y, Lee, WD, Griffith, LG, Bawendi, MG, and Kirsch, DG. "Intraoperative detection and removal of microscopic residual sarcoma using wide-field imaging." Cancer 118.21 (November 1, 2012): 5320-5330.
PMID
22437667
Source
pubmed
Published In
Cancer
Volume
118
Issue
21
Publish Date
2012
Start Page
5320
End Page
5330
DOI
10.1002/cncr.27458

In Reply to O'Sullivan et al.

Authors
Wang, D; Bosch, W; Roberge, D; Finkelstein, SE; Petersen, I; Haddock, M; Chen, Y-LE; Delaney, TF; Saito, NG; Kirsch, DG; Hitchcock, YJ; Wolfson, AH
MLA Citation
Wang, D, Bosch, W, Roberge, D, Finkelstein, SE, Petersen, I, Haddock, M, Chen, Y-LE, Delaney, TF, Saito, NG, Kirsch, DG, Hitchcock, YJ, and Wolfson, AH. "In Reply to O'Sullivan et al." Int J Radiat Oncol Biol Phys 84.2 (October 1, 2012): 307-308. (Letter)
PMID
22935393
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
84
Issue
2
Publish Date
2012
Start Page
307
End Page
308
DOI
10.1016/j.ijrobp.2012.05.038

Pathologic complete response of a malignant peripheral nerve sheath tumor in the lung treated with neoadjuvant Ifosfamide and radiation therapy.

Authors
Cuneo, KC; Riedel, RF; Dodd, LG; Harpole, DH; Kirsch, DG
MLA Citation
Cuneo, KC, Riedel, RF, Dodd, LG, Harpole, DH, and Kirsch, DG. "Pathologic complete response of a malignant peripheral nerve sheath tumor in the lung treated with neoadjuvant Ifosfamide and radiation therapy." J Clin Oncol 30.28 (October 1, 2012): e291-e293.
PMID
22869889
Source
pubmed
Published In
Journal of Clinical Oncology
Volume
30
Issue
28
Publish Date
2012
Start Page
e291
End Page
e293
DOI
10.1200/JCO.2012.42.8797

p53 functions in endothelial cells to prevent radiation-induced myocardial injury in mice.

Radiation therapy, which is used for the treatment of some cancers, can cause delayed heart damage. In the heart, p53 influences myocardial injury that occurs after multiple types of stress. Here, we demonstrated that p53 functioned in endothelial cells to protect mice from myocardial injury after whole-heart irradiation. Mice with an endothelial cell-specific deletion of p53 succumbed to heart failure after whole-heart irradiation as a result of myocardial necrosis, systolic dysfunction, and cardiac hypertrophy. Moreover, the onset of cardiac dysfunction was preceded by alterations in myocardial vascular permeability and density, which resulted in cardiac ischemia and myocardial hypoxia. Mechanistic studies with primary cardiac endothelial cells irradiated in vitro indicated that p53 signaling caused mitotic arrest and protected cardiac endothelial cells from cell death resulting from abnormal mitosis or mitotic catastrophe. Furthermore, mice lacking the cyclin-dependent kinase inhibitor p21, which is a transcriptional target of p53, were also sensitized to myocardial injury after whole-heart irradiation. Together, our results demonstrate that the p53-p21 axis functions to prevent radiation-induced myocardial injury in mice.

Authors
Lee, C-L; Moding, EJ; Cuneo, KC; Li, Y; Sullivan, JM; Mao, L; Washington, I; Jeffords, LB; Rodrigues, RC; Ma, Y; Das, S; Kontos, CD; Kim, Y; Rockman, HA; Kirsch, DG
MLA Citation
Lee, C-L, Moding, EJ, Cuneo, KC, Li, Y, Sullivan, JM, Mao, L, Washington, I, Jeffords, LB, Rodrigues, RC, Ma, Y, Das, S, Kontos, CD, Kim, Y, Rockman, HA, and Kirsch, DG. "p53 functions in endothelial cells to prevent radiation-induced myocardial injury in mice. (Published online)" Sci Signal 5.234 (July 24, 2012): ra52-.
PMID
22827996
Source
pubmed
Published In
Science Signaling
Volume
5
Issue
234
Publish Date
2012
Start Page
ra52
DOI
10.1126/scisignal.2002918

SU-E-T-275: Dose Verification in a Small Animal Image-Guided Radiation Therapy X-Ray Machine: A Dose Comparison between TG-61 Based Look-Up Table and MOSFET Method for Various Collimator Sizes.

To verify the accuracy of TG-61 based dosimetry with MOSFET technology using a tissue-equivalent mouse phantom.Accuracy of mouse dose between a TG-61 based look-up table was verified with MOSFET technology. The look-up table followed a TG-61 based commissioning and used a solid water block and radiochromic film. A tissue-equivalent mouse phantom (2 cm diameter, 8 cm length) was used for the MOSFET method. Detectors were placed in the phantom at the head and center of the body. MOSFETs were calibrated in air with an ion chamber and f-factor was applied to derive the dose to tissue. In CBCT mode, the phantom was positioned such that the system isocenter coincided with the center of the MOSFET with the active volume perpendicular to the beam. The absorbed dose was measured three times for seven different collimators, respectively. The exposure parameters were 225 kVp, 13 mA, and an exposure time of 20 s.For a 10 mm, 15 mm, and 20 mm circular collimator, the dose measured by the phantom was 4.3%, 2.7%, and 6% lower than TG-61 based measurements, respectively. For a 10 × 10 mm, 20 × 20 mm, and 40 × 40 mm collimator, the dose difference was 4.7%, 7.7%, and 2.9%, respectively.The MOSFET data was systematically lower than the commissioning data. The dose difference is due to the increased scatter radiation in the solid water block versus the dimension of the mouse phantom leading to an overestimation of the actual dose in the solid water block. The MOSFET method with the use of a tissue- equivalent mouse phantom provides less labor intensive geometry-specific dosimetry and accuracy with better dose tolerances of up to ± 2.7%.

Authors
Rodrigues, A; Nguyen, G; Li, Y; Roy Choudhury, K; Kirsch, D; Das, S; Yoshizumi, T
MLA Citation
Rodrigues, A, Nguyen, G, Li, Y, Roy Choudhury, K, Kirsch, D, Das, S, and Yoshizumi, T. "SU-E-T-275: Dose Verification in a Small Animal Image-Guided Radiation Therapy X-Ray Machine: A Dose Comparison between TG-61 Based Look-Up Table and MOSFET Method for Various Collimator Sizes." Medical physics 39.6Part14 (June 2012): 3766-.
PMID
28517298
Source
epmc
Published In
Medical physics
Volume
39
Issue
6Part14
Publish Date
2012
Start Page
3766
DOI
10.1118/1.4735343

TU-C-BRB-02: Identification of a Targeting Error in a Small Field Biological Irradiator Using 3D Dosimetry Techniques

Authors
Newton, J; Li, Y; Adamovics, J; Kirsch, D; Das, S; Oldham, M
MLA Citation
Newton, J, Li, Y, Adamovics, J, Kirsch, D, Das, S, and Oldham, M. "TU-C-BRB-02: Identification of a Targeting Error in a Small Field Biological Irradiator Using 3D Dosimetry Techniques." June 2012.
Source
crossref
Published In
Medical physics
Volume
39
Issue
6Part23
Publish Date
2012
Start Page
3898
End Page
3898
DOI
10.1118/1.4735914

Generation of primary tumors with Flp recombinase in FRT-flanked p53 mice.

The site-specific recombinases Cre and Flp can mutate genes in a spatially and temporally restricted manner in mice. Conditional recombination of the tumor suppressor gene p53 using the Cre-loxP system has led to the development of multiple genetically engineered mouse models of human cancer. However, the use of Cre recombinase to initiate tumors in mouse models limits the utilization of Cre to genetically modify other genes in tumor stromal cells in these models. To overcome this limitation, we inserted FRT (flippase recognition target) sites flanking exons 2-6 of the endogenous p53 gene in mice to generate a p53(FRT) allele that can be deleted by Flp recombinase. We show that FlpO-mediated deletion of p53 in mouse embryonic fibroblasts impairs the p53-dependent response to genotoxic stress in vitro. In addition, using FSF-Kras(G12D/+); p53(FRT/FRT) mice, we demonstrate that an adenovirus expressing FlpO recombinase can initiate primary lung cancers and sarcomas in mice. p53(FRT) mice will enable dual recombinase technology to study cancer biology because Cre is available to modify genes specifically in stromal cells to investigate their role in tumor development, progression and response to therapy.

Authors
Lee, C-L; Moding, EJ; Huang, X; Li, Y; Woodlief, LZ; Rodrigues, RC; Ma, Y; Kirsch, DG
MLA Citation
Lee, C-L, Moding, EJ, Huang, X, Li, Y, Woodlief, LZ, Rodrigues, RC, Ma, Y, and Kirsch, DG. "Generation of primary tumors with Flp recombinase in FRT-flanked p53 mice." Dis Model Mech 5.3 (May 2012): 397-402.
PMID
22228755
Source
pubmed
Published In
Disease models & mechanisms
Volume
5
Issue
3
Publish Date
2012
Start Page
397
End Page
402
DOI
10.1242/dmm.009084

p21 protects "Super p53" mice from the radiation-induced gastrointestinal syndrome.

Exposure of the gastrointestinal (GI) tract to high doses of radiation can lead to lethality from the GI syndrome. Although the molecular mechanism regulating the GI syndrome remains to be fully defined, we have recently demonstrated that p53 within the GI epithelial cells controls the radiation-induced GI syndrome. Mice lacking p53 in the GI epithelium were sensitized to the GI syndrome, while transgenic mice with one additional copy of p53 called "Super p53" mice were protected from the GI syndrome. Here, we crossed Super p53 mice to p21⁻/⁻ mice that lack the cyclin-dependent kinase inhibitor p21. Super p53; p21⁻/⁻ mice were sensitized to the GI syndrome compared to Super p53 mice that retain one p21 allele. In addition, mice lacking p21 were not protected from the GI syndrome with one extra copy of p53. These results suggest that p21 protects Super p53 mice from the GI syndrome.

Authors
Sullivan, JM; Jeffords, LB; Lee, C-L; Rodrigues, R; Ma, Y; Kirsch, DG
MLA Citation
Sullivan, JM, Jeffords, LB, Lee, C-L, Rodrigues, R, Ma, Y, and Kirsch, DG. "p21 protects "Super p53" mice from the radiation-induced gastrointestinal syndrome." Radiat Res 177.3 (March 2012): 307-310.
PMID
22165824
Source
pubmed
Published In
Radiation Research
Volume
177
Issue
3
Publish Date
2012
Start Page
307
End Page
310

Computed tomography imaging of primary lung cancer in mice using a liposomal-iodinated contrast agent.

PURPOSE: To investigate the utility of a liposomal-iodinated nanoparticle contrast agent and computed tomography (CT) imaging for characterization of primary nodules in genetically engineered mouse models of non-small cell lung cancer. METHODS: Primary lung cancers with mutations in K-ras alone (Kras(LA1)) or in combination with p53 (LSL-Kras(G12D);p53(FL/FL)) were generated. A liposomal-iodine contrast agent containing 120 mg Iodine/mL was administered systemically at a dose of 16 µl/gm body weight. Longitudinal micro-CT imaging with cardio-respiratory gating was performed pre-contrast and at 0 hr, day 3, and day 7 post-contrast administration. CT-derived nodule sizes were used to assess tumor growth. Signal attenuation was measured in individual nodules to study dynamic enhancement of lung nodules. RESULTS: A good correlation was seen between volume and diameter-based assessment of nodules (R(2)>0.8) for both lung cancer models. The LSL-Kras(G12D);p53(FL/FL) model showed rapid growth as demonstrated by systemically higher volume changes compared to the lung nodules in Kras(LA1) mice (p<0.05). Early phase imaging using the nanoparticle contrast agent enabled visualization of nodule blood supply. Delayed-phase imaging demonstrated significant differential signal enhancement in the lung nodules of LSL-Kras(G12D);p53(FL/FL) mice compared to nodules in Kras(LA1) mice (p<0.05) indicating higher uptake and accumulation of the nanoparticle contrast agent in rapidly growing nodules. CONCLUSIONS: The nanoparticle iodinated contrast agent enabled visualization of blood supply to the nodules during the early-phase imaging. Delayed-phase imaging enabled characterization of slow growing and rapidly growing nodules based on signal enhancement. The use of this agent could facilitate early detection and diagnosis of pulmonary lesions as well as have implications on treatment response and monitoring.

Authors
Badea, CT; Athreya, KK; Espinosa, G; Clark, D; Ghafoori, AP; Li, Y; Kirsch, DG; Johnson, GA; Annapragada, A; Ghaghada, KB
MLA Citation
Badea, CT, Athreya, KK, Espinosa, G, Clark, D, Ghafoori, AP, Li, Y, Kirsch, DG, Johnson, GA, Annapragada, A, and Ghaghada, KB. "Computed tomography imaging of primary lung cancer in mice using a liposomal-iodinated contrast agent." PLoS One 7.4 (2012): e34496-.
PMID
22485175
Source
pubmed
Published In
PloS one
Volume
7
Issue
4
Publish Date
2012
Start Page
e34496
DOI
10.1371/journal.pone.0034496

Embryonic signaling pathways and rhabdomyosarcoma: contributions to cancer development and opportunities for therapeutic targeting.

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood and adolescence, accounting for approximately 7% of childhood cancers. Current therapies include nonspecific cytotoxic chemotherapy regimens, radiation therapy, and surgery; however, these multimodality strategies are unsuccessful in the majority of patients with high-risk disease. It is generally believed that these tumors represent arrested or aberrant skeletal muscle development, and, accordingly, developmental signaling pathways critical to myogenesis such as Notch, WNT, and Hedgehog may represent new therapeutic targets. In this paper, we summarize the current preclinical studies linking these embryonic pathways to rhabdomyosarcoma tumorigenesis and provide support for the investigation of targeted therapies in this embryonic cancer.

Authors
Belyea, B; Kephart, JG; Blum, J; Kirsch, DG; Linardic, CM
MLA Citation
Belyea, B, Kephart, JG, Blum, J, Kirsch, DG, and Linardic, CM. "Embryonic signaling pathways and rhabdomyosarcoma: contributions to cancer development and opportunities for therapeutic targeting." Sarcoma 2012 (2012): 406239-.
PMID
22619564
Source
pubmed
Published In
Sarcoma
Volume
2012
Publish Date
2012
Start Page
406239
DOI
10.1155/2012/406239

Efficacy of phosphatidylinositol-3 kinase inhibitors in a primary mouse model of undifferentiated pleomorphic sarcoma.

Recent advances in sarcoma genomics have identified novel mutations in the PI3K pathway in human sarcomas. Here, we use a mouse model of primary soft-tissue sarcoma for preclinical testing of doxorubicin and inhibitors of the PI3K pathway: BKM120 (PI3K inhibitor) and BEZ235 (a dual PI3K/mTOR inhibitor). Doxorubicin-treated tumors (n = 15) showed a partial response rate of 6.6%, just as the majority of human sarcomas do not respond to doxorubicin. Treatment with BKM120 elicited a partial response in 50% of tumors (n = 10), which was also seen in combination with doxorubicin (n = 10). Additionally, BKM120 treatment produced a robust delay in tumor growth kinetics. BEZ235-treated tumors (n = 9) showed a complete response rate of 11.1%. Combining BEZ235 with doxorubicin (n = 10) increased the complete response rate to 50% (P = 0.035). These studies demonstrate that PI3K pathway inhibition is a viable and attractive target for soft-tissue sarcomas.

Authors
Kim, S; Dodd, RD; Mito, JK; Ma, Y; Kim, Y; Riedel, RF; Kirsch, DG
MLA Citation
Kim, S, Dodd, RD, Mito, JK, Ma, Y, Kim, Y, Riedel, RF, and Kirsch, DG. "Efficacy of phosphatidylinositol-3 kinase inhibitors in a primary mouse model of undifferentiated pleomorphic sarcoma." Sarcoma 2012 (2012): 680708-.
PMID
22619567
Source
pubmed
Published In
Sarcoma
Volume
2012
Publish Date
2012
Start Page
680708
DOI
10.1155/2012/680708

Data analysis: evaluation of nanoscale contrast agent enhanced CT scan to differentiate between benign and malignant lung cancer in mouse model.

Proposed is a method for statistical analysis for a small sample size, repeated measure experiment with nesting factors. In the original experiment the Student t-test was used for analysis. Using the same data, we modeled the experiment into two groups of mice with benign and malignant primary lung tumors. 4 tumor nodules were selected from each mouse (N= 36). The dependent variables are the volume, diameter, and signal attenuation measured using computed tomography (CT). The measurements are made before injecting the contrast and at 0, 72, and 168 hours after injection. The contrast agent enhances tumor nodule volume and volume differences between benign and malignant tumor nodules measured across time (p < 0.05). The signal attenuation measured across time differentiates between benign and malignant groups (p < 0.05). There is significant correlation between rate of change of volume and diameter of tumor. The advantages of this statistical method are discussed.

Authors
Bell, RC; Rogith, D; Johnson, CW; Badea, CT; Athreya, KK; Espinosa, G; Clark, D; Ghafoori, AP; Li, Y; Kirsch, DG; Annapragada, A; Ghaghada, K
MLA Citation
Bell, RC, Rogith, D, Johnson, CW, Badea, CT, Athreya, KK, Espinosa, G, Clark, D, Ghafoori, AP, Li, Y, Kirsch, DG, Annapragada, A, and Ghaghada, K. "Data analysis: evaluation of nanoscale contrast agent enhanced CT scan to differentiate between benign and malignant lung cancer in mouse model." AMIA Annu Symp Proc 2012 (2012): 27-35.
PMID
23304269
Source
pubmed
Published In
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium
Volume
2012
Publish Date
2012
Start Page
27
End Page
35

Variation in the gross tumor volume and clinical target volume for preoperative radiotherapy of primary large high-grade soft tissue sarcoma of the extremity among RTOG sarcoma radiation oncologists.

PURPOSE: To evaluate variability in the definition of preoperative radiotherapy gross tumor volume (GTV) and clinical target volume (CTV) delineated by sarcoma radiation oncologists. METHODS AND MATERIALS: Extremity sarcoma planning CT images along with the corresponding diagnostic MRI from two patients were distributed to 10 Radiation Therapy Oncology Group sarcoma radiation oncologists with instructions to define GTV and CTV using standardized guidelines. The CT data with contours were then returned for central analysis. Contours representing statistically corrected 95% (V95) and 100% (V100) agreement were computed for each structure. RESULTS: For the GTV, the minimum, maximum, mean (SD) volumes (mL) were 674, 798, 752±35 for the lower extremity case and 383, 543, 447±46 for the upper extremity case. The volume (cc) of the union, V95 and V100 were 882, 761, and 752 for the lower, and 587, 461, and 455 for the upper extremity, respectively. The overall GTV agreement was judged to be almost perfect in both lower and upper extremity cases (kappa=0.9 [p<0.0001] and kappa=0.86 [p<0.0001]). For the CTV, the minimum, maximum, mean (SD) volumes (mL) were 1145, 1911, 1605±211 for the lower extremity case and 637, 1246, 1006±180 for the upper extremity case. The volume (cc) of the union, V95, and V100 were 2094, 1609, and 1593 for the lower, and 1533, 1020, and 965 for the upper extremity cases, respectively. The overall CTV agreement was judged to be almost perfect in the lower extremity case (kappa=0.85 [p<0.0001]) but only substantial in the upper extremity case (kappa=0.77 [p<0.0001]). CONCLUSIONS: Almost perfect agreement existed in the GTV of these two representative cases. There was no significant disagreement in the CTV of the lower extremity, but variation in the CTV of upper extremity was seen, perhaps related to the positional differences between the planning CT and the diagnostic MRI.

Authors
Wang, D; Bosch, W; Kirsch, DG; Al Lozi, R; El Naqa, I; Roberge, D; Finkelstein, SE; Petersen, I; Haddock, M; Chen, Y-LE; Saito, NG; Hitchcock, YJ; Wolfson, AH; DeLaney, TF
MLA Citation
Wang, D, Bosch, W, Kirsch, DG, Al Lozi, R, El Naqa, I, Roberge, D, Finkelstein, SE, Petersen, I, Haddock, M, Chen, Y-LE, Saito, NG, Hitchcock, YJ, Wolfson, AH, and DeLaney, TF. "Variation in the gross tumor volume and clinical target volume for preoperative radiotherapy of primary large high-grade soft tissue sarcoma of the extremity among RTOG sarcoma radiation oncologists." Int J Radiat Oncol Biol Phys 81.5 (December 1, 2011): e775-e780.
PMID
21277104
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
81
Issue
5
Publish Date
2011
Start Page
e775
End Page
e780
DOI
10.1016/j.ijrobp.2010.11.033

Commissioning a small-field biological irradiator using point, 2D, and 3D dosimetry techniques.

PURPOSE: To commission a small-field biological irradiator, the XRad225Cx from Precision x-Ray, Inc., for research use. The system produces a 225 kVp x-ray beam and is equipped with collimating cones that produce both square and circular radiation fields ranging in size from 1 to 40 mm. This work incorporates point, 2D, and 3D measurements to determine output factors (OF), percent-depth-dose (PDD) and dose profiles at multiple depths. METHODS: Three independent dosimetry systems were used: ion-chambers (a farmer chamber and a micro-ionisation chamber), 2D EBT2 radiochromic film, and a novel 3D dosimetry system (DLOS∕PRESAGE®). Reference point dose rates and output factors were determined from in-air ionization chamber measurements for fields down to ∼13 mm using the formalism of TG61. PDD, profiles, and output factors at three separate depths (0, 0.5, and 2 cm), were determined for all field sizes from EBT2 film measurements in solid water. Several film PDD curves required a scaling correction, reflecting the challenge of accurate film alignment in very small fields. PDDs, profiles, and output factors were also determined with the 3D DLOS∕PRESAGE® system which generated isotropic 0.2 mm data, in scan times of 20 min. RESULTS: Surface output factors determined by ion-chamber were observed to gradually drop by ∼9% when the field size was reduced from 40 to 13 mm. More dramatic drops were observed for the smallest fields as determined by EBT∼18% and ∼42% for the 2.5 mm and 1 mm fields, respectively. PRESAGE® and film output factors agreed well for fields <20 mm (where 3D data were available) with mean deviation of 2.2% (range 1%-4%). PDD values at 2 cm depth varied from ∼72% for the 40 mm field, down to ∼55% for the 1 mm field. EBT and PRESAGE® PDDs agreed within ∼3% in the typical therapy region (1-4 cm). At deeper depths the EBT curves were slightly steeper (2.5% at 5 cm). These results indicate good overall consistency between ion-chamber, EBT2 and PRESAGE® measured OFs, PDDs, and profiles. CONCLUSIONS: The combination of independent 2D and 3D measurements was found to be valuable to ensure accurate and comprehensive commissioning. Film measurements were time consuming and challenging due to the difficulty of film alignment in small fields. PRESAGE® 3D measurements were comprehensive and efficient, because alignment errors are negligible, and all parameters for multiple fields could be obtained from a single dosimeter and scan. However, achieving accurate superficial data (within 4 mm) is not yet feasible due to optical surface artifacts.

Authors
Newton, J; Oldham, M; Thomas, A; Li, Y; Adamovics, J; Kirsch, DG; Das, S
MLA Citation
Newton, J, Oldham, M, Thomas, A, Li, Y, Adamovics, J, Kirsch, DG, and Das, S. "Commissioning a small-field biological irradiator using point, 2D, and 3D dosimetry techniques." Med Phys 38.12 (December 2011): 6754-6762.
PMID
22149857
Source
pubmed
Published In
Medical physics
Volume
38
Issue
12
Publish Date
2011
Start Page
6754
End Page
6762
DOI
10.1118/1.3663675

In vivo assessment of an absorbable and nonabsorbable knotless barbed suture for laparoscopic single-layer enterotomy closure: a clinical and biomechanical comparison against nonbarbed suture.

BACKGROUND: Laparoscopic intracorporeal suturing and knot tying is a complex skill that requires repeated deliberate practice to master. A novel self-anchoring barbed suture material that does not require knot tying can eliminate knot failure and reduce operating time. The goal of this study was to compare the in vivo efficacy of two novel knotless barbed sutures (absorbable and nonabsorbable) for use with the Endo Stitch™ device (Covidien), against conventional suture (Endo Stitch device with Polysorb™ suture; Covidien) for laparoscopic closure of viscerotomies in canine stomach, jejunum, and colon. METHODS: Following Institutional Animal Care and Use Committee approval, 24 dogs underwent laparoscopic creation of 25-mm viscerotomies, three each in the stomach, jejunum, and colon. All viscerotomies were closed with the Endo Stitch device using the absorbable or nonabsorbable barbed suture or conventional suture. Closure time for each viscerotomy was recorded. Animals were survived for 3, 10, or 21 days, at which point the viscerotomies were burst-pressure tested. RESULTS: The closure leak rate in this study with 216 total viscerotomy closures was 0%. There was no statistically significant difference in mean burst pressure between viscerotomies closed with barbed suture versus control suture at any of the survival intervals. Barbed suture with the Endo Stitch device was associated with statistically significantly faster closure times than the control suture with the Endo Stitch device (P<.05), resulting in a reduction in closure time between 35% and 42%. CONCLUSION: This study reports the first use of barbed suture for the Endo Stitch device in laparoscopic gastrointestinal closure. The barbed suture for the Endo Stitch device is effective for laparoscopic single-layer gastrointestinal closure and is associated with a significantly reduced closure time.

Authors
Omotosho, P; Yurcisin, B; Ceppa, E; Miller, J; Kirsch, D; Portenier, DD
MLA Citation
Omotosho, P, Yurcisin, B, Ceppa, E, Miller, J, Kirsch, D, and Portenier, DD. "In vivo assessment of an absorbable and nonabsorbable knotless barbed suture for laparoscopic single-layer enterotomy closure: a clinical and biomechanical comparison against nonbarbed suture." J Laparoendosc Adv Surg Tech A 21.10 (December 2011): 893-897.
PMID
22129144
Source
pubmed
Published In
Journal of Laparoendoscopic & Advanced Surgical Techniques
Volume
21
Issue
10
Publish Date
2011
Start Page
893
End Page
897
DOI
10.1089/lap.2011.0281

Phase II study of neoadjuvant bevacizumab and radiotherapy for resectable soft tissue sarcomas.

PURPOSE: Numerous preclinical studies have demonstrated that angiogenesis inhibitors can increase the efficacy of radiotherapy (RT). We sought to examine the safety and efficacy of bevacizumab (BV) and RT in soft tissue sarcomas and explore biomarkers to help determine the treatment response. METHODS AND MATERIALS: Patients with ≥5 cm, intermediate- or high-grade soft tissue sarcomas at significant risk of local recurrence received neoadjuvant BV alone followed by BV plus RT before surgical resection. Correlative science studies included analysis of the serial blood and tumor samples and serial perfusion computed tomography scans. RESULTS: The 20 patients had a median tumor size of 8.25 cm, with 13 extremity, 1 trunk, and 6 retroperitoneal/pelvis tumors. The neoadjuvant treatment was well tolerated, with only 4 patients having Grade 3 toxicities (hypertension, liver function test elevation). BV plus RT resulted in ≥80% pathologic necrosis in 9 (45%) of 20 tumors, more than double the historical rate seen with RT alone. Three patients had a complete pathologic response. The median microvessel density decreased 53% after BV alone (p <.05). After combination therapy, the median tumor cell proliferation decreased by 73%, apoptosis increased 10.4-fold, and the blood flow, blood volume, and permeability surface area decreased by 62-72% (p <.05). Analysis of gene expression microarrays of untreated tumors identified a 24-gene signature for treatment response. The microvessel density and circulating progenitor cells at baseline and the reduction in microvessel density and plasma soluble c-KIT with BV therapy also correlated with a good pathologic response (p <.05). After a median follow-up of 20 months, only 1 patient had developed local recurrence. CONCLUSIONS: The results from the present exploratory study indicated that BV increases the efficacy of RT against soft tissue sarcomas and might reduce the incidence of local recurrence. Thus, this regimen warrants additional investigation. Gene expression profiles and other tissue and circulating biomarkers showed promising correlations with treatment response.

Authors
Yoon, SS; Duda, DG; Karl, DL; Kim, T-M; Kambadakone, AR; Chen, Y-L; Rothrock, C; Rosenberg, AE; Nielsen, GP; Kirsch, DG; Choy, E; Harmon, DC; Hornicek, FJ; Dreyfuss, J; Ancukiewicz, M; Sahani, DV; Park, PJ; Jain, RK; Delaney, TF
MLA Citation
Yoon, SS, Duda, DG, Karl, DL, Kim, T-M, Kambadakone, AR, Chen, Y-L, Rothrock, C, Rosenberg, AE, Nielsen, GP, Kirsch, DG, Choy, E, Harmon, DC, Hornicek, FJ, Dreyfuss, J, Ancukiewicz, M, Sahani, DV, Park, PJ, Jain, RK, and Delaney, TF. "Phase II study of neoadjuvant bevacizumab and radiotherapy for resectable soft tissue sarcomas." Int J Radiat Oncol Biol Phys 81.4 (November 15, 2011): 1081-1090.
PMID
20932656
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
81
Issue
4
Publish Date
2011
Start Page
1081
End Page
1090
DOI
10.1016/j.ijrobp.2010.07.024

RTOG sarcoma radiation oncologists reach consensus on gross tumor volume and clinical target volume on computed tomographic images for preoperative radiotherapy of primary soft tissue sarcoma of extremity in Radiation Therapy Oncology Group studies.

OBJECTIVE: To develop a Radiation Therapy Oncology Group (RTOG) atlas delineating gross tumor volume (GTV) and clinical target volume (CTV) to be used for preoperative radiotherapy of primary extremity soft tissue sarcoma (STS). METHODS AND MATERIALS: A consensus meeting was held during the RTOG meeting in January 2010 to reach agreement about GTV and CTV delineation on computed tomography (CT) images for preoperative radiotherapy of high-grade large extremity STS. Data were presented to address the local extension of STS. Extensive discussion ensued to develop optimal criteria for GTV and CTV delineation on CT images. RESULTS: A consensus was reached on appropriate CT-based GTV and CTV. The GTV is gross tumor defined by T1 contrast-enhanced magnetic resonance images. Fusion of magnetic resonance and images is recommended to delineate the GTV. The CTV for high-grade large STS typically includes the GTV plus 3-cm margins in the longitudinal directions. If this causes the field to extend beyond the compartment, the field can be shortened to include the end of a compartment. The radial margin from the lesion should be 1.5 cm, including any portion of the tumor not confined by an intact fascial barrier, bone, or skin surface. CONCLUSION: The consensus on GTV and CTV for preoperative radiotherapy of high-grade large extremity STS is available as web-based images and in a descriptive format through the RTOG. This is expected to improve target volume consistency and allow for rigorous evaluation of the benefits and risks of such treatment.

Authors
Wang, D; Bosch, W; Roberge, D; Finkelstein, SE; Petersen, I; Haddock, M; Chen, Y-LE; Saito, NG; Kirsch, DG; Hitchcock, YJ; Wolfson, AH; DeLaney, TF
MLA Citation
Wang, D, Bosch, W, Roberge, D, Finkelstein, SE, Petersen, I, Haddock, M, Chen, Y-LE, Saito, NG, Kirsch, DG, Hitchcock, YJ, Wolfson, AH, and DeLaney, TF. "RTOG sarcoma radiation oncologists reach consensus on gross tumor volume and clinical target volume on computed tomographic images for preoperative radiotherapy of primary soft tissue sarcoma of extremity in Radiation Therapy Oncology Group studies." Int J Radiat Oncol Biol Phys 81.4 (November 15, 2011): e525-e528.
PMID
21676552
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
81
Issue
4
Publish Date
2011
Start Page
e525
End Page
e528
DOI
10.1016/j.ijrobp.2011.04.038

Using genetically engineered mice for radiation research.

The laboratory mouse has been used for many decades as a model system for radiation research. Recent advances in genetic engineering now allow scientists to delete genes in specific cell types at different stages of development. The ability to manipulate genes in the mouse with spatial and temporal control opens new opportunities to investigate the role of genes in regulating the response of normal tissues and tumors to radiation. Currently, we are using the Cre-loxP system to delete genes, such as p53, in a cell-type specific manner in mice to study mechanisms of acute radiation injury and late effects of radiation. Our results demonstrate that p53 is required in the gastrointestinal (GI) epithelium to prevent radiation-induced GI syndrome and in endothelial and/or hematopoietic cells to prevent late effects of radiation. We have also used these genetic tools to generate primary tumors in mice to study tumor response to radiation therapy. These advances in genetic engineering provide a powerful model system to dissect both the mechanisms of normal tissue injury after irradiation and the mechanisms by which radiation cures cancer.

Authors
Kirsch, DG
MLA Citation
Kirsch, DG. "Using genetically engineered mice for radiation research." Radiat Res 176.3 (September 2011): 275-279.
PMID
21867429
Source
pubmed
Published In
Radiation Research
Volume
176
Issue
3
Publish Date
2011
Start Page
275
End Page
279

The Holman Research Pathway in radiation oncology.

Authors
Weidhaas, JB; Kirsch, DG
MLA Citation
Weidhaas, JB, and Kirsch, DG. "The Holman Research Pathway in radiation oncology." Int J Radiat Oncol Biol Phys 80.2 (June 1, 2011): 321-323.
PMID
21549248
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
80
Issue
2
Publish Date
2011
Start Page
321
End Page
323
DOI
10.1016/j.ijrobp.2011.01.030

p53 controls radiation-induced gastrointestinal syndrome in mice independent of apoptosis (Science (593), (2010))

Authors
Kirsch, DG
MLA Citation
Kirsch, DG. "p53 controls radiation-induced gastrointestinal syndrome in mice independent of apoptosis (Science (593), (2010))." Science 334.6057 (2011): 761--.
Source
scival
Published In
Science
Volume
334
Issue
6057
Publish Date
2011
Start Page
761-
DOI
10.1126/science.334.6057.761-b

In response to Dr. Garbow and colleagues

Authors
Kirsch, DG; Grimm, J; Guimaraes, AR; Weissleder, R
MLA Citation
Kirsch, DG, Grimm, J, Guimaraes, AR, and Weissleder, R. "In response to Dr. Garbow and colleagues." International Journal of Radiation Oncology Biology Physics 79.3 (2011): 959--.
Source
scival
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
79
Issue
3
Publish Date
2011
Start Page
959-
DOI
10.1016/j.ijrobp.2010.10.046

Animal models of soft-tissue sarcoma.

Soft-tissue sarcomas (STSs) are rare mesenchymal tumors that arise from muscle, fat and connective tissue. Currently, over 75 subtypes of STS are recognized. The rarity and heterogeneity of patient samples complicate clinical investigations into sarcoma biology. Model organisms might provide traction to our understanding and treatment of the disease. Over the past 10 years, many successful animal models of STS have been developed, primarily genetically engineered mice and zebrafish. These models are useful for studying the relevant oncogenes, signaling pathways and other cell changes involved in generating STSs. Recently, these model systems have become preclinical platforms in which to evaluate new drugs and treatment regimens. Thus, animal models are useful surrogates for understanding STS disease susceptibility and pathogenesis as well as for testing potential therapeutic strategies.

Authors
Dodd, RD; Mito, JK; Kirsch, DG
MLA Citation
Dodd, RD, Mito, JK, and Kirsch, DG. "Animal models of soft-tissue sarcoma." Dis Model Mech 3.9-10 (September 2010): 557-566. (Review)
Website
http://hdl.handle.net/10161/4183
PMID
20713645
Source
pubmed
Published In
Disease models & mechanisms
Volume
3
Issue
9-10
Publish Date
2010
Start Page
557
End Page
566
DOI
10.1242/dmm.005223

Primary tumor genotype is an important determinant in identification of lung cancer propagating cells.

Successful cancer therapy requires the elimination or incapacitation of all tumor cells capable of regenerating a tumor. Therapeutic advances therefore necessitate the characterization of the cells that are able to propagate a tumor in vivo. We show an important link between tumor genotype and isolation of tumor-propagating cells (TPCs). Three mouse models of the most common form of human lung cancer each had TPCs with a unique cell-surface phenotype. The cell-surface marker Sca1 did not enrich for TPCs in tumors initiated with oncogenic Kras, and only Sca1-negative cells propagated EGFR mutant tumors. In contrast, Sca1-positive cells were enriched for tumor-propagating activity in Kras tumors with p53 deficiency. Primary tumors that differ in genotype at just one locus can therefore have tumor-propagating cell populations with distinct markers. Our studies show that the genotype of tumor samples must be considered in studies to identify, characterize, and target tumor-propagating cells.

Authors
Curtis, SJ; Sinkevicius, KW; Li, D; Lau, AN; Roach, RR; Zamponi, R; Woolfenden, AE; Kirsch, DG; Wong, K-K; Kim, CF
MLA Citation
Curtis, SJ, Sinkevicius, KW, Li, D, Lau, AN, Roach, RR, Zamponi, R, Woolfenden, AE, Kirsch, DG, Wong, K-K, and Kim, CF. "Primary tumor genotype is an important determinant in identification of lung cancer propagating cells." Cell Stem Cell 7.1 (July 2, 2010): 127-133.
PMID
20621056
Source
pubmed
Published In
Cell Stem Cell
Volume
7
Issue
1
Publish Date
2010
Start Page
127
End Page
133
DOI
10.1016/j.stem.2010.05.021

An effective preoperative three-dimensional radiotherapy target volume for extremity soft tissue sarcoma and the effect of margin width on local control.

PURPOSE: There is little information on the appropriate three-dimensional (3D) preoperative radiotherapy (XRT) volume for extremity soft-tissue sarcomas (STS). We retrospectively analyzed the pattern of local failure (LF) to help elucidate optimal field design. METHODS AND MATERIALS: We analyzed the 56 patients who underwent computed tomography-planned XRT for Stage I to III extremity STS between June 2000 and December 2006. Clinical target volume (CTV) included the T1 post-gadolinium-defined gross tumor volume with 1- to 1.5-cm radial and 3.5-cm longitudinal margins. Planning target volume expansion was 5 to 7 mm, and >or=95% of dose was delivered to the planning target volume. Preoperative XRT was 44 to 50.4 Gy (median, 50). Postoperative boost of 10 to 20 Gy was given to 12 patients (6 with positive and 6 with close margins). RESULTS: Follow-up ranged from 15 to 76 months (median, 41 months). The 5-year local control, freedom from distant metastasis, disease-free survival, and overall survival were 88.5%, 80.0%, 77.5% and 82.8%, respectively. Three patients (all with positive margin) experienced local failure (LF) as first relapse (2 isolated, 1 with distant failure), and 2 additional patients (all with margin<1 mm) had late LF after distant metastasis. The LFs were within the CTV in 3 patients and within and also extending beyond the CTV in 2 patients. CONCLUSIONS: These target volume definitions appear to be appropriate for most patients. No local recurrences were observed with surgical margins >or=1 mm, and it appears that these may be adequate for patients with extremity STS treated with preoperative radiotherapy.

Authors
Kim, B; Chen, Y-LE; Kirsch, DG; Goldberg, SI; Kobayashi, W; Kung, JH; Wolfgang, JA; Doppke, K; Rosenberg, AE; Nielsen, GP; Raskin, KA; Springfield, DS; Schwab, JH; Gebhardt, MC; Yoon, SS; Hornicek, FJ; DeLaney, TF
MLA Citation
Kim, B, Chen, Y-LE, Kirsch, DG, Goldberg, SI, Kobayashi, W, Kung, JH, Wolfgang, JA, Doppke, K, Rosenberg, AE, Nielsen, GP, Raskin, KA, Springfield, DS, Schwab, JH, Gebhardt, MC, Yoon, SS, Hornicek, FJ, and DeLaney, TF. "An effective preoperative three-dimensional radiotherapy target volume for extremity soft tissue sarcoma and the effect of margin width on local control." Int J Radiat Oncol Biol Phys 77.3 (July 1, 2010): 843-850.
PMID
20005638
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
77
Issue
3
Publish Date
2010
Start Page
843
End Page
850
DOI
10.1016/j.ijrobp.2009.06.086

Proton-beam, intensity-modulated, and/or intraoperative electron radiation therapy combined with aggressive anterior surgical resection for retroperitoneal sarcomas.

BACKGROUND: We sought to reduce local recurrence for retroperitoneal sarcomas by using a coordinated strategy of advanced radiation techniques and aggressive en-bloc surgical resection. METHODS: Proton-beam radiation therapy (PBRT) and/or intensity-modulated radiation therapy (IMRT) were delivered to improve tumor target coverage and spare selected adjacent organs. Surgical resection of tumor and adjacent organs was performed to obtain a disease-free anterior margin. Intraoperative electron radiation therapy (IOERT) was delivered to any close posterior margin. RESULTS: Twenty patients had primary tumors and eight had recurrent tumors. Tumors were large (median size 9.75 cm), primarily liposarcomas and leiomyosarcomas (71%), and were mostly of intermediate or high grade (81%). PBRT and/or IMRT were delivered to all patients, preferably preoperatively (75%), to a median dose of 50 Gy. Surgical resection included up to five adjacent organs, most commonly the colon (n = 7) and kidney (n = 7). Margins were positive for disease, usually posteriorly, in 15 patients (54%). IOERT was delivered to the posterior margin in 12 patients (43%) to a median dose of 11 Gy. Surgical complications occurred in eight patients (28.6%), and radiation-related complications occurred in four patients (14%). After a median follow-up of 33 months, only two patients (10%) with primary disease experienced local recurrence, while three patients (37.5%) with recurrent disease experienced local recurrence. CONCLUSIONS: Aggressive resection of retroperitoneal sarcomas can achieve a disease-negative anterior margin. PBRT and/or IMRT with IOERT may possibly deliver sufficient radiation dose to the posterior margin to control microscopic residual disease. This strategy may minimize radiation-related morbidity and reduce local recurrence, especially in patients with primary disease.

Authors
Yoon, SS; Chen, Y-L; Kirsch, DG; Maduekwe, UN; Rosenberg, AE; Nielsen, GP; Sahani, DV; Choy, E; Harmon, DC; DeLaney, TF
MLA Citation
Yoon, SS, Chen, Y-L, Kirsch, DG, Maduekwe, UN, Rosenberg, AE, Nielsen, GP, Sahani, DV, Choy, E, Harmon, DC, and DeLaney, TF. "Proton-beam, intensity-modulated, and/or intraoperative electron radiation therapy combined with aggressive anterior surgical resection for retroperitoneal sarcomas." Ann Surg Oncol 17.6 (June 2010): 1515-1529.
PMID
20151216
Source
pubmed
Published In
Annals of Surgical Oncology
Volume
17
Issue
6
Publish Date
2010
Start Page
1515
End Page
1529
DOI
10.1245/s10434-010-0935-1

Animal models for medical countermeasures to radiation exposure.

Since September 11, 2001, there has been the recognition of a plausible threat from acts of terrorism, including radiological or nuclear attacks. A network of Centers for Medical Countermeasures against Radiation (CMCRs) has been established across the U.S.; one of the missions of this network is to identify and develop mitigating agents that can be used to treat the civilian population after a radiological event. The development of such agents requires comparison of data from many sources and accumulation of information consistent with the "Animal Rule" from the Food and Drug Administration (FDA). Given the necessity for a consensus on appropriate animal model use across the network to allow for comparative studies to be performed across institutions, and to identify pivotal studies and facilitate FDA approval, in early 2008, investigators from each of the CMCRs organized and met for an Animal Models Workshop. Working groups deliberated and discussed the wide range of animal models available for assessing agent efficacy in a number of relevant tissues and organs, including the immune and hematopoietic systems, gastrointestinal tract, lung, kidney and skin. Discussions covered the most appropriate species and strains available as well as other factors that may affect differential findings between groups and institutions. This report provides the workshop findings.

Authors
Williams, JP; Brown, SL; Georges, GE; Hauer-Jensen, M; Hill, RP; Huser, AK; Kirsch, DG; Macvittie, TJ; Mason, KA; Medhora, MM; Moulder, JE; Okunieff, P; Otterson, MF; Robbins, ME; Smathers, JB; McBride, WH
MLA Citation
Williams, JP, Brown, SL, Georges, GE, Hauer-Jensen, M, Hill, RP, Huser, AK, Kirsch, DG, Macvittie, TJ, Mason, KA, Medhora, MM, Moulder, JE, Okunieff, P, Otterson, MF, Robbins, ME, Smathers, JB, and McBride, WH. "Animal models for medical countermeasures to radiation exposure." Radiat Res 173.4 (April 2010): 557-578.
PMID
20334528
Source
pubmed
Published In
Radiation Research
Volume
173
Issue
4
Publish Date
2010
Start Page
557
End Page
578
DOI
10.1667/RR1880.1

Imaging primary lung cancers in mice to study radiation biology.

PURPOSE: To image a genetically engineered mouse model of non-small-cell lung cancer with micro-computed tomography (micro-CT) to measure tumor response to radiation therapy. METHODS AND MATERIALS: The Cre-loxP system was used to generate primary lung cancers in mice with mutation in K-ras alone or in combination with p53 mutation. Mice were serially imaged by micro-CT, and tumor volumes were determined. A comparison of tumor volume by micro-CT and tumor histology was performed. Tumor response to radiation therapy (15.5 Gy) was assessed with micro-CT. RESULTS: The tumor volume measured with free-breathing micro-CT scans was greater than the volume calculated by histology. Nevertheless, this imaging approach demonstrated that lung cancers with mutant p53 grew more rapidly than lung tumors with wild-type p53 and also showed that radiation therapy increased the doubling time of p53 mutant lung cancers fivefold. CONCLUSIONS: Micro-CT is an effective tool to noninvasively measure the growth of primary lung cancers in genetically engineered mice and assess tumor response to radiation therapy. This imaging approach will be useful to study the radiation biology of lung cancer.

Authors
Kirsch, DG; Grimm, J; Guimaraes, AR; Wojtkiewicz, GR; Perez, BA; Santiago, PM; Anthony, NK; Forbes, T; Doppke, K; Weissleder, R; Jacks, T
MLA Citation
Kirsch, DG, Grimm, J, Guimaraes, AR, Wojtkiewicz, GR, Perez, BA, Santiago, PM, Anthony, NK, Forbes, T, Doppke, K, Weissleder, R, and Jacks, T. "Imaging primary lung cancers in mice to study radiation biology." Int J Radiat Oncol Biol Phys 76.4 (March 15, 2010): 973-977.
PMID
20206017
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
76
Issue
4
Publish Date
2010
Start Page
973
End Page
977
DOI
10.1016/j.ijrobp.2009.11.038

Phase-selective image reconstruction of the lungs in small animals using Micro-CT.

Gating in small animal imaging can compensate for artifacts due to physiological motion. This paper presents a strategy for sampling and image reconstruction in the rodent lung using micro-CT. The approach involves rapid sampling of free-breathing mice without any additional hardware to detect respiratory motion. The projection images are analyzed post-acquisition to derive a respiratory signal, which is used to provide weighting factors for each projection that favor a selected phase of the respiration (e.g. end-inspiration or end-expiration) for the reconstruction. Since the sampling cycle and the respiratory cycle are uncorrelated, the sets of projections corresponding to any of the selected respiratory phases do not have a regular angular distribution. This drastically affects the image quality of reconstructions based on simple filtered backprojection. To address this problem, we use an iterative reconstruction algorithm that combines the Simultaneous Algebraic Reconstruction Technique with Total Variation minimization (SART-TV). At each SART-TV iteration, backprojection is performed with a set of weighting factors that favor the desired respiratory phase. To reduce reconstruction time, the algorithm is implemented on a graphics processing unit. The performance of the proposed approach was investigated in simulations and in vivo scans of mice with primary lung cancers imaged with our in-house developed dual tube/detector micro-CT system. We note that if the ECG signal is acquired during sampling, the same approach could be used for phase-selective cardiac imaging.

Authors
Johnston, SM; Perez, BA; Kirsch, DG; Badea, CT
MLA Citation
Johnston, SM, Perez, BA, Kirsch, DG, and Badea, CT. "Phase-selective image reconstruction of the lungs in small animals using Micro-CT." Proc SPIE Int Soc Opt Eng 7622 (February 15, 2010): 76223G.1-76223G.9.
PMID
21243034
Source
pubmed
Published In
Proceedings of SPIE - The International Society for Optical Engineering
Volume
7622
Publish Date
2010
Start Page
76223G.1
End Page
76223G.9
DOI
10.1117/12.844359

p53 controls radiation-induced gastrointestinal syndrome in mice independent of apoptosis.

Acute exposure to ionizing radiation can cause lethal damage to the gastrointestinal (GI) tract, a condition called the GI syndrome. Whether the target cells affected by radiation to cause the GI syndrome are derived from the epithelium or endothelium and whether the target cells die by apoptosis or other mechanisms are controversial issues. Studying mouse models, we found that selective deletion of the proapoptotic genes Bak1 and Bax from the GI epithelium or from endothelial cells did not protect mice from developing the GI syndrome after sub-total-body gamma irradiation. In contrast, selective deletion of p53 from the GI epithelium, but not from endothelial cells, sensitized irradiated mice to the GI syndrome. Transgenic mice overexpressing p53 in all tissues were protected from the GI syndrome after irradiation. These results suggest that the GI syndrome is caused by the death of GI epithelial cells and that these epithelial cells die by a mechanism that is regulated by p53 but independent of apoptosis.

Authors
Kirsch, DG; Santiago, PM; di Tomaso, E; Sullivan, JM; Hou, W-S; Dayton, T; Jeffords, LB; Sodha, P; Mercer, KL; Cohen, R; Takeuchi, O; Korsmeyer, SJ; Bronson, RT; Kim, CF; Haigis, KM; Jain, RK; Jacks, T
MLA Citation
Kirsch, DG, Santiago, PM, di Tomaso, E, Sullivan, JM, Hou, W-S, Dayton, T, Jeffords, LB, Sodha, P, Mercer, KL, Cohen, R, Takeuchi, O, Korsmeyer, SJ, Bronson, RT, Kim, CF, Haigis, KM, Jain, RK, and Jacks, T. "p53 controls radiation-induced gastrointestinal syndrome in mice independent of apoptosis." Science 327.5965 (January 29, 2010): 593-596.
PMID
20019247
Source
pubmed
Published In
Science
Volume
327
Issue
5965
Publish Date
2010
Start Page
593
End Page
596
DOI
10.1126/science.1166202

Dicer1 functions as a haploinsufficient tumor suppressor.

While the global down-regulation of microRNAs (miRNAs) is a common feature of human tumors, its genetic basis is largely undefined. To explore this question, we analyzed the consequences of conditional Dicer1 mutation (Dicer1 "floxed" or Dicer1(fl)) on several mouse models of cancer. Here we show Dicer1 functions as a haploinsufficient tumor suppressor gene. Deletion of a single copy of Dicer1 in tumors from Dicer1(fl/+) animals led to reduced survival compared with controls. These tumors exhibited impaired miRNA processing but failed to lose the wild-type Dicer1 allele. Moreover, tumors from Dicer1(fl/fl) animals always maintained one functional Dicer1 allele. Consistent with selection against full loss of Dicer1 expression, enforced Dicer1 deletion caused inhibition of tumorigenesis. Analysis of human cancer genome copy number data reveals frequent deletion of DICER1. Importantly, however, the gene has not been reported to undergo homozygous deletion, suggesting that DICER1 is haploinsufficient in human cancer. These findings suggest Dicer1 may be an important haploinsufficient tumor suppressor gene and, furthermore, that other factors controlling miRNA biogenesis may also function in this manner.

Authors
Kumar, MS; Pester, RE; Chen, CY; Lane, K; Chin, C; Lu, J; Kirsch, DG; Golub, TR; Jacks, T
MLA Citation
Kumar, MS, Pester, RE, Chen, CY, Lane, K, Chin, C, Lu, J, Kirsch, DG, Golub, TR, and Jacks, T. "Dicer1 functions as a haploinsufficient tumor suppressor." Genes Dev 23.23 (December 1, 2009): 2700-2704.
PMID
19903759
Source
pubmed
Published In
Genes & development
Volume
23
Issue
23
Publish Date
2009
Start Page
2700
End Page
2704
DOI
10.1101/gad.1848209

Cross species genomic analysis identifies a mouse model as undifferentiated pleomorphic sarcoma/malignant fibrous histiocytoma.

Undifferentiated pleomorphic sarcoma/Malignant Fibrous Histiocytoma (MFH) is one of the most common subtypes of human soft tissue sarcoma. Using cross species genomic analysis, we define a geneset from the LSL-Kras(G12D); Trp53(Flox/Flox) mouse model of soft tissue sarcoma that is highly enriched in human MFH. With this mouse geneset as a filter, we identify expression of the RAS target FOXM1 in human MFH. Expression of Foxm1 is elevated in mouse sarcomas that metastasize to the lung and tissue microarray analysis of human MFH correlates overexpression of FOXM1 with metastasis. These results suggest that genomic alterations present in human MFH are conserved in the LSL-Kras(G12D); p53(Flox/Flox) mouse model of soft tissue sarcoma and demonstrate the utility of this pre-clinical model.

Authors
Mito, JK; Riedel, RF; Dodd, L; Lahat, G; Lazar, AJ; Dodd, RD; Stangenberg, L; Eward, WC; Hornicek, FJ; Yoon, SS; Brigman, BE; Jacks, T; Lev, D; Mukherjee, S; Kirsch, DG
MLA Citation
Mito, JK, Riedel, RF, Dodd, L, Lahat, G, Lazar, AJ, Dodd, RD, Stangenberg, L, Eward, WC, Hornicek, FJ, Yoon, SS, Brigman, BE, Jacks, T, Lev, D, Mukherjee, S, and Kirsch, DG. "Cross species genomic analysis identifies a mouse model as undifferentiated pleomorphic sarcoma/malignant fibrous histiocytoma. (Published online)" PLoS One 4.11 (November 30, 2009): e8075-.
PMID
19956606
Source
pubmed
Published In
PloS one
Volume
4
Issue
11
Publish Date
2009
Start Page
e8075
DOI
10.1371/journal.pone.0008075

Efficacy of sunitinib and radiotherapy in genetically engineered mouse model of soft-tissue sarcoma.

PURPOSE: Sunitinib (SU) is a multitargeted receptor tyrosine kinase inhibitor of the vascular endothelial growth factor and platelet-derived growth factor receptors. The present study examined SU and radiotherapy (RT) in a genetically engineered mouse model of soft tissue sarcoma (STS). METHODS AND MATERIALS: Primary extremity STSs were generated in genetically engineered mice. The mice were randomized to treatment with SU, RT (10 Gy x 2), or both (SU+RT). Changes in the tumor vasculature before and after treatment were assessed in vivo using fluorescence-mediated tomography. The control and treated tumors were harvested and extensively analyzed. RESULTS: The mean fluorescence in the tumors was not decreased by RT but decreased 38-44% in tumors treated with SU or SU+RT. The control tumors grew to a mean of 1378 mm(3) after 12 days. SU alone or RT alone delayed tumor growth by 56% and 41%, respectively, but maximal growth inhibition (71%) was observed with the combination therapy. SU target effects were confirmed by loss of target receptor phosphorylation and alterations in SU-related gene expression. Cancer cell proliferation was decreased and apoptosis increased in the SU and RT groups, with a synergistic effect on apoptosis observed in the SU+RT group. RT had a minimal effect on the tumor microvessel density and endothelial cell-specific apoptosis, but SU alone or SU+RT decreased the microvessel density by >66% and induced significant endothelial cell apoptosis. CONCLUSION: SU inhibited STS growth by effects on both cancer cells and tumor vasculature. SU also augmented the efficacy of RT, suggesting that this combination strategy could improve local control of STS.

Authors
Yoon, SS; Stangenberg, L; Lee, Y-J; Rothrock, C; Dreyfuss, JM; Baek, K-H; Waterman, PR; Nielsen, GP; Weissleder, R; Mahmood, U; Park, PJ; Jacks, T; Dodd, RD; Fisher, CJ; Ryeom, S; Kirsch, DG
MLA Citation
Yoon, SS, Stangenberg, L, Lee, Y-J, Rothrock, C, Dreyfuss, JM, Baek, K-H, Waterman, PR, Nielsen, GP, Weissleder, R, Mahmood, U, Park, PJ, Jacks, T, Dodd, RD, Fisher, CJ, Ryeom, S, and Kirsch, DG. "Efficacy of sunitinib and radiotherapy in genetically engineered mouse model of soft-tissue sarcoma." Int J Radiat Oncol Biol Phys 74.4 (July 15, 2009): 1207-1216.
PMID
19545786
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
74
Issue
4
Publish Date
2009
Start Page
1207
End Page
1216
DOI
10.1016/j.ijrobp.2009.02.052

The clinical management of chondrosarcoma.

OPINION STATEMENT: Chondrosarcomas (CHS) represent a heterogeneous group of disorders ranging from indolent, low-grade tumors to aggressive, high-grade forms. Surgical resection represents the primary and preferred treatment modality for individuals with localized disease. Radiation therapy is appropriate for the treatment of positive surgical margins or palliation of disease-related symptoms. The treatment of advanced, metastatic disease is particularly challenging given the recognition that conventional chemotherapy has proven to be largely ineffective. Systemic chemotherapy may be considered in variant forms such as mesenchymal or dedifferentiated chondrosarcomas but high-quality data supporting its use is limited. There is universal agreement, however, that novel treatment strategies are desperately needed. This review will highlight the need for a coordinated multidisciplinary approach to optimize the management and care of patients.

Authors
Riedel, RF; Larrier, N; Dodd, L; Kirsch, D; Martinez, S; Brigman, BE
MLA Citation
Riedel, RF, Larrier, N, Dodd, L, Kirsch, D, Martinez, S, and Brigman, BE. "The clinical management of chondrosarcoma." Curr Treat Options Oncol 10.1-2 (April 2009): 94-106. (Review)
PMID
19238552
Source
pubmed
Published In
Current Treatment Options in Oncology
Volume
10
Issue
1-2
Publish Date
2009
Start Page
94
End Page
106
DOI
10.1007/s11864-009-0088-2

Combination short-course preoperative irradiation, surgical resection, and reduced-field high-dose postoperative irradiation in the treatment of tumors involving the bone.

PURPOSE: To assess the feasibility and outcomes of combination short-course preoperative radiation, resection, and reduced-field (tumor bed without operative field coverage) high-dose postoperative radiation for patients with solid tumors mainly involving the spine and pelvis. METHODS AND MATERIALS: Between 1982 and 2006, a total of 48 patients were treated using this treatment strategy for solid tumors involving bone. Radiation treatments used both photons and protons. RESULTS: Of those treated, 52% had chordoma, 31% had chondrosarcoma, 8% had osteosarcoma, and 4% had Ewing's sarcoma, with 71% involving the pelvis/sacrum and 21% elsewhere in the spine. Median preoperative dose was 20 Gy, with a median of 50.4 Gy postoperatively. With 31.8-month median follow-up, the 5-year overall survival (OS) rate is 65%; 5-year disease-free survival (DFS) rate, 53.8%; and 5-year local control (LC) rate, 72%. There were no significant differences in OS, DFS, and LC according to histologic characteristics. Between primary and recurrent disease, there was no significant difference in OS rates (74.4% vs. 51.4%, respectively; p = 0.128), in contrast to DFS (71.5% vs. 18.3%; p = 0.0014) and LC rates (88.9% vs. 30.9%; p = 0.0011) favoring primary disease. After resection, 10 patients experienced delayed wound healing that did not significantly impact on OS, DFS, or LC. CONCLUSION: This approach is promising for patients with bone sarcomas in which resection will likely yield close/positive margins. It appears to inhibit tumor seeding with an acceptable rate of wound-healing complications. Dose escalation is accomplished without high-dose preoperative radiation (likely associated with higher rates of acute wound healing delays) or large-field postoperative radiation only (likely associated with late normal tissue toxicity). The LC and DFS rates are substantially better for patients with primary than recurrent sarcomas.

Authors
Wagner, TD; Kobayashi, W; Dean, S; Goldberg, SI; Kirsch, DG; Suit, HD; Hornicek, FJ; Pedlow, FX; Raskin, KA; Springfield, DS; Yoon, SS; Gebhardt, MC; Mankin, HJ; Delaney, TF
MLA Citation
Wagner, TD, Kobayashi, W, Dean, S, Goldberg, SI, Kirsch, DG, Suit, HD, Hornicek, FJ, Pedlow, FX, Raskin, KA, Springfield, DS, Yoon, SS, Gebhardt, MC, Mankin, HJ, and Delaney, TF. "Combination short-course preoperative irradiation, surgical resection, and reduced-field high-dose postoperative irradiation in the treatment of tumors involving the bone." Int J Radiat Oncol Biol Phys 73.1 (January 1, 2009): 259-266.
PMID
19100921
Source
pubmed
Published In
International Journal of Radiation: Oncology - Biology - Physics
Volume
73
Issue
1
Publish Date
2009
Start Page
259
End Page
266
DOI
10.1016/j.ijrobp.2008.03.074

Barbed suture for gastrointestinal closure: A randomized control trial

In an effort to make laparoscopic suturing more efficient, the V-Loc advanced wound closure device (Covidien, Mansfield, MA) has been produced. This device is a self-anchoring barbed suture that obviates the need for knot tying. The goal of this initial feasibility study was to investigate the use of the barbed suture in gastrointestinal enterotomy closure. A randomized study of 12 pigs comparing enterotomy closure with barbed versus a nonbarbed suture of similar tensile strength was performed. To this end, 25 mm enterotomies were made in the stomach (1 control, 1 treatment), jejunum (2 controls, 2 treatments), and descending colon (1 control, 1 treatment). Animals were killed at 3, 7, and 14 days postoperatively (4 each group) and their gastrointestinal tracts harvested; 6 of the 8 enterotomies from each pig underwent burst strength testing. The remaining 2 were fixed in formalin and sent for histological examination. All 12 pigs survived until they were killed without any major complications. Enterotomy closure with barbed suture revealed adhesion scores, burst strength pressures, and histology scores that were similar to those for the control. Jejunal closures resulted in 6 failures at 7 days (3 control, 3 barbed) and 4 failures at 14 days (2 control, 2 barbed). The barbed suture significantly reduced suturing time in the stomach, jejunum, and colon. The V-Loc wound closure device appears to offer comparable gastrointestinal closure to 3-0 Maxon while being significantly faster. Further studies with V-Loc are required to assess its use in laparoscopic surgery.

Authors
Demyttenaere, SV; Nau, P; Henn, M; Beck, C; Zaruby, J; Primavera, M; Kirsch, D; Miller, J; Liu, JJ; Bellizzi, A; Melvin, WS
MLA Citation
Demyttenaere, SV, Nau, P, Henn, M, Beck, C, Zaruby, J, Primavera, M, Kirsch, D, Miller, J, Liu, JJ, Bellizzi, A, and Melvin, WS. "Barbed suture for gastrointestinal closure: A randomized control trial." Surgical Innovation 16.3 (2009): 237-242.
PMID
19783567
Source
scival
Published In
Surgical Innovation
Volume
16
Issue
3
Publish Date
2009
Start Page
237
End Page
242
DOI
10.1177/1553350609342988

Early photon tomography allows fluorescence detection of lung carcinomas and disease progression in mice in vivo.

Imaging of targeted fluorescent probes offers significant advantages for investigating disease and tissue function in animal models in vivo. Conversely, macroscopic tomographic imaging is challenging because of the high scatter of light in biological tissue and the ill-posed nature of the reconstruction mathematics. In this work, we use the earliest-transmitted photons through Lewis Lung Carcinoma bearing mice, thereby dramatically reducing the effect of tissue scattering. By using a fluorescent probe sensitive to cysteine proteases, the method yielded outstanding imaging performance compared with conventional approaches. Accurate visualization of biochemical abnormalities was achieved, not only in the primary tumor, but also in the surrounding tissue related to cancer progression and inflammatory response at the organ level. These findings were confirmed histologically and with ex vivo fluorescence microscopy. The imaging fidelity demonstrated underscores a method that can use a wide range of fluorescent probes to accurately visualize cellular- and molecular-level events in whole animals in vivo.

Authors
Niedre, MJ; de Kleine, RH; Aikawa, E; Kirsch, DG; Weissleder, R; Ntziachristos, V
MLA Citation
Niedre, MJ, de Kleine, RH, Aikawa, E, Kirsch, DG, Weissleder, R, and Ntziachristos, V. "Early photon tomography allows fluorescence detection of lung carcinomas and disease progression in mice in vivo." Proc Natl Acad Sci U S A 105.49 (December 9, 2008): 19126-19131.
PMID
19015534
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
105
Issue
49
Publish Date
2008
Start Page
19126
End Page
19131
DOI
10.1073/pnas.0804798105

Phase II trial of lapatinib for brain metastases in patients with human epidermal growth factor receptor 2-positive breast cancer.

PURPOSE: One third of women with advanced human epidermal growth factor receptor 2 (HER-2)-positive breast cancer develop brain metastases; a subset progress in the CNS despite standard approaches. Medical therapies for refractory brain metastases are neither well-studied nor established. We evaluated the safety and efficacy of lapatinib, an oral inhibitor of epidermal growth factor receptor (EGFR) and HER-2, in patients with HER-2-positive brain metastases. PATIENTS AND METHODS: Patients had HER-2-positive breast cancer, progressive brain metastases, prior trastuzumab treatment, and at least one measurable metastatic brain lesion. Patients received lapatinib 750 mg orally twice a day. Tumor response was assessed by magnetic resonance imaging every 8 weeks. The primary end point was objective response (complete response [CR] plus partial response [PR]) in the CNS by Response Evaluation Criteria in Solid Tumors (RECIST). Secondary end points included objective response in non-CNS sites, time to progression, overall survival, and toxicity. RESULTS: Thirty-nine patients were enrolled. All patients had developed brain metastases while receiving trastuzumab; 37 had progressed after prior radiation. One patient achieved a PR in the brain by RECIST (objective response rate 2.6%, 95% conditional CI, 0.21% to 26%). Seven patients (18%) were progression free in both CNS and non-CNS sites at 16 weeks. Exploratory analyses identified additional patients with some degree of volumetric reduction in brain tumor burden. The most common adverse events (AEs) were diarrhea (grade 3, 21%) and fatigue (grade 3, 15%). CONCLUSION: The study did not meet the predefined criteria for antitumor activity in highly refractory patients with HER-2-positive brain metastases. Because of the volumetric changes observed in our exploratory analysis, further studies are underway utilizing volumetric changes as a primary end point.

Authors
Lin, NU; Carey, LA; Liu, MC; Younger, J; Come, SE; Ewend, M; Harris, GJ; Bullitt, E; Van den Abbeele, AD; Henson, JW; Li, X; Gelman, R; Burstein, HJ; Kasparian, E; Kirsch, DG; Crawford, A; Hochberg, F; Winer, EP
MLA Citation
Lin, NU, Carey, LA, Liu, MC, Younger, J, Come, SE, Ewend, M, Harris, GJ, Bullitt, E, Van den Abbeele, AD, Henson, JW, Li, X, Gelman, R, Burstein, HJ, Kasparian, E, Kirsch, DG, Crawford, A, Hochberg, F, and Winer, EP. "Phase II trial of lapatinib for brain metastases in patients with human epidermal growth factor receptor 2-positive breast cancer." J Clin Oncol 26.12 (April 20, 2008): 1993-1999.
PMID
18421051
Source
pubmed
Published In
Journal of Clinical Oncology
Volume
26
Issue
12
Publish Date
2008
Start Page
1993
End Page
1999
DOI
10.1200/JCO.2007.12.3588

A spatially and temporally restricted mouse model of soft tissue sarcoma.

Soft tissue sarcomas are mesenchymal tumors that are fatal in approximately one-third of patients. To explore mechanisms of sarcoma pathogenesis, we have generated a mouse model of soft tissue sarcoma. Intramuscular delivery of an adenovirus expressing Cre recombinase in mice with conditional mutations in Kras and Trp53 was sufficient to initiate high-grade sarcomas with myofibroblastic differentiation. Like human sarcomas, these tumors show a predilection for lung rather than lymph node metastasis. Using this model, we showed that a prototype handheld imaging device can identify residual tumor during intraoperative molecular imaging. Deletion of the Ink4a-Arf locus (Cdkn2a), but not Bak1 and Bax, could substitute for mutation of Trp53 in this model. Deletion of Bak1 and Bax, however, was able to substitute for mutation of Trp53 in the development of sinonasal adenocarcinoma. Therefore, the intrinsic pathway of apoptosis seems sufficient to mediate p53 tumor suppression in an epithelial cancer, but not in this model of soft tissue sarcoma.

Authors
Kirsch, DG; Dinulescu, DM; Miller, JB; Grimm, J; Santiago, PM; Young, NP; Nielsen, GP; Quade, BJ; Chaber, CJ; Schultz, CP; Takeuchi, O; Bronson, RT; Crowley, D; Korsmeyer, SJ; Yoon, SS; Hornicek, FJ; Weissleder, R; Jacks, T
MLA Citation
Kirsch, DG, Dinulescu, DM, Miller, JB, Grimm, J, Santiago, PM, Young, NP, Nielsen, GP, Quade, BJ, Chaber, CJ, Schultz, CP, Takeuchi, O, Bronson, RT, Crowley, D, Korsmeyer, SJ, Yoon, SS, Hornicek, FJ, Weissleder, R, and Jacks, T. "A spatially and temporally restricted mouse model of soft tissue sarcoma." Nat Med 13.8 (August 2007): 992-997.
PMID
17676052
Source
pubmed
Published In
Nature Medicine
Volume
13
Issue
8
Publish Date
2007
Start Page
992
End Page
997
DOI
10.1038/nm1602

Treatment and outcome of 82 patients with angiosarcoma.

BACKGROUND: Angiosarcomas are an uncommon type of malignancy that are generally thought to behave usually in a locally aggressive fashion; they often metastasize to distant sites. METHODS: Patients with a diagnosis of angiosarcoma treated at our institution between 1980 and 2006 were analyzed for patient demographics, tumor characteristics, multimodality treatment, and outcomes. RESULTS: A total of 82 patients were divided into those with primary and advanced disease. Overall, the median age was 65 (range, 22-91) years, and 44% of patients were women. Median size of tumors was 3.8 cm, and 76% of tumors were intermediate or high grade. Tumors were located throughout the body: 32 cutaneous, 22 deep soft tissues or organs, 10 radiation or lymphedema field, 8 bone, and 7 nonirradiated breast. Of 46 patients with primary disease, all patients underwent surgical resection, 67% received radiotherapy, and 27% received chemotherapy. Five-year disease-specific survival was 60%, and negative prognostic factors included intermediate or high grade, and tumors arising in a radiated or lymphedema field. Of 36 patients with advanced disease, 36% underwent a palliative operation, 78% received radiation, and 58% received chemotherapy. Median survival was just 7.3 months, and cutaneous tumors predicted a better prognosis compared with other sites. CONCLUSIONS: Primary angiosarcomas treated with aggressive surgical resection and the addition of radiation for close margins or worrisome pathologic features can result in long-term survival in most patients. The role of adjuvant chemotherapy is unclear. Patients with advanced disease have a poor prognosis, but there can be dramatic responses to chemotherapy in a minority of patients.

Authors
Abraham, JA; Hornicek, FJ; Kaufman, AM; Harmon, DC; Springfield, DS; Raskin, KA; Mankin, HJ; Kirsch, DG; Rosenberg, AE; Nielsen, GP; Desphpande, V; Suit, HD; DeLaney, TF; Yoon, SS
MLA Citation
Abraham, JA, Hornicek, FJ, Kaufman, AM, Harmon, DC, Springfield, DS, Raskin, KA, Mankin, HJ, Kirsch, DG, Rosenberg, AE, Nielsen, GP, Desphpande, V, Suit, HD, DeLaney, TF, and Yoon, SS. "Treatment and outcome of 82 patients with angiosarcoma." Ann Surg Oncol 14.6 (June 2007): 1953-1967.
PMID
17356953
Source
pubmed
Published In
Annals of Surgical Oncology
Volume
14
Issue
6
Publish Date
2007
Start Page
1953
End Page
1967
DOI
10.1245/s10434-006-9335-y

Radiation therapy for control of soft-tissue sarcomas resected with positive margins.

PURPOSE: Positive margins (PM) remain after surgery in some soft-tissue sarcoma (STS) patients. We investigated the efficacy of radiation therapy (RT) in STS patients with PM. METHODS AND MATERIALS: A retrospective chart review was performed on 154 patients with STS at various anatomic sites with PM, defined as tumor on ink, who underwent RT with curative intent between 1970 and 2001. Local control (LC), disease-free survival (DFS), and overall survival (OS) rates were evaluated by univariate (log-rank) and multivariate analysis of prognostic and treatment factors. RESULTS: At 5 years, actuarial LC, DFS, and OS rates were: 76%, 46.7%, and 65.2%, respectively. LC was highest with extremity lesions (p < 0.01), radiation dose >64 Gy (p < 0.05), microscopically (vs. grossly visible) positive margin (p = 0.03), and superficial lesions (p = 0.05). Patients receiving >64 Gy had higher 5-year LC, DFS, and OS rates of 85%, 52.1%, and 67.8% vs. 66.1%, 41.8%, and 62.9% if < or =64 Gy, p < 0.04. OS was worse in patients with G2/G3 tumors with local failure (LF), p < 0.001. Other known prognostic factors, including grade, stage, size, and age (>50), also significantly influenced OS. By multivariate analysis, the best predictors of LC were site (extremity vs. other), p < 0.01 and dose (>64 vs. < or =64 Gy), p < 0.05; the best predictors for OS were size, p < 0.001, gross vs. microscopic PM, p < 0.05, and LF, p < 0.01. CONCLUSION: Local control is achieved in most PM STS patients undergoing RT. Doses >64 Gy, superficial location, and extremity site are associated with improved LC. OS is worse in patients with tumors with lesions >5 cm, grossly positive margins, and after local failure.

Authors
Delaney, TF; Kepka, L; Goldberg, SI; Hornicek, FJ; Gebhardt, MC; Yoon, SS; Springfield, DS; Raskin, KA; Harmon, DC; Kirsch, DG; Mankin, HJ; Rosenberg, AE; Nielsen, GP; Suit, HD
MLA Citation
Delaney, TF, Kepka, L, Goldberg, SI, Hornicek, FJ, Gebhardt, MC, Yoon, SS, Springfield, DS, Raskin, KA, Harmon, DC, Kirsch, DG, Mankin, HJ, Rosenberg, AE, Nielsen, GP, and Suit, HD. "Radiation therapy for control of soft-tissue sarcomas resected with positive margins." Int J Radiat Oncol Biol Phys 67.5 (April 1, 2007): 1460-1469.
PMID
17394945
Source
pubmed
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
67
Issue
5
Publish Date
2007
Start Page
1460
End Page
1469
DOI
10.1016/j.ijrobp.2006.11.035

Restoration of p53 function leads to tumour regression in vivo.

Tumorigenesis is a multi-step process that requires activation of oncogenes and inactivation of tumour suppressor genes. Mouse models of human cancers have recently demonstrated that continuous expression of a dominantly acting oncogene (for example, Hras, Kras and Myc) is often required for tumour maintenance; this phenotype is referred to as oncogene addiction. This concept has received clinical validation by the development of active anticancer drugs that specifically inhibit the function of oncoproteins such as BCR-ABL, c-KIT and EGFR. Identifying additional gene mutations that are required for tumour maintenance may therefore yield clinically useful targets for new cancer therapies. Although loss of p53 function is a common feature of human cancers, it is not known whether sustained inactivation of this or other tumour suppressor pathways is required for tumour maintenance. To explore this issue, we developed a Cre-loxP-based strategy to temporally control tumour suppressor gene expression in vivo. Here we show that restoring endogenous p53 expression leads to regression of autochthonous lymphomas and sarcomas in mice without affecting normal tissues. The mechanism responsible for tumour regression is dependent on the tumour type, with the main consequence of p53 restoration being apoptosis in lymphomas and suppression of cell growth with features of cellular senescence in sarcomas. These results support efforts to treat human cancers by way of pharmacological reactivation of p53.

Authors
Ventura, A; Kirsch, DG; McLaughlin, ME; Tuveson, DA; Grimm, J; Lintault, L; Newman, J; Reczek, EE; Weissleder, R; Jacks, T
MLA Citation
Ventura, A, Kirsch, DG, McLaughlin, ME, Tuveson, DA, Grimm, J, Lintault, L, Newman, J, Reczek, EE, Weissleder, R, and Jacks, T. "Restoration of p53 function leads to tumour regression in vivo." Nature 445.7128 (February 8, 2007): 661-665.
PMID
17251932
Source
pubmed
Published In
Nature
Volume
445
Issue
7128
Publish Date
2007
Start Page
661
End Page
665
DOI
10.1038/nature05541

Alternate functions of viral regulators of cell death.

Authors
Chen, Y-B; Seo, SY; Kirsch, DG; Sheu, T-T; Cheng, W-C; Hardwick, JM
MLA Citation
Chen, Y-B, Seo, SY, Kirsch, DG, Sheu, T-T, Cheng, W-C, and Hardwick, JM. "Alternate functions of viral regulators of cell death." Cell Death Differ 13.8 (August 2006): 1318-1324. (Review)
PMID
16741528
Source
pubmed
Published In
Cell Death & Differentiation
Volume
13
Issue
8
Publish Date
2006
Start Page
1318
End Page
1324
DOI
10.1038/sj.cdd.4401964

Use of gene expression profiling to direct in vivo molecular imaging of lung cancer.

Using gene expression profiling, we identified cathepsin cysteine proteases as highly up-regulated genes in a mouse model of human lung adenocarcinoma. Overexpression of cathepsin proteases in these lung tumors was confirmed by immunohistochemistry and Western blotting. Therefore, an optical probe activated by cathepsin proteases was selected to detect murine lung tumors in vivo as small as 1 mm in diameter and spatially separated. We generated 3D maps of the fluorescence signal and fused them with anatomical computed tomography images to show a close correlation between fluorescence signal and tumor burden. By serially imaging the same mouse, optical imaging was used to follow tumor progression. This study demonstrates the capability for molecular imaging of a primary lung tumor by using endogenous proteases expressed by a tumor. It also highlights the feasibility of using gene expression profiling to identify molecular targets for imaging lung cancer.

Authors
Grimm, J; Kirsch, DG; Windsor, SD; Kim, CFB; Santiago, PM; Ntziachristos, V; Jacks, T; Weissleder, R
MLA Citation
Grimm, J, Kirsch, DG, Windsor, SD, Kim, CFB, Santiago, PM, Ntziachristos, V, Jacks, T, and Weissleder, R. "Use of gene expression profiling to direct in vivo molecular imaging of lung cancer." Proc Natl Acad Sci U S A 102.40 (October 4, 2005): 14404-14409.
PMID
16183744
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
102
Issue
40
Publish Date
2005
Start Page
14404
End Page
14409
DOI
10.1073/pnas.0503920102

Future of early detection of lung cancer: the role of mouse models.

Early detection represents one of the most promising approaches to improving lung cancer survival. To date, no screening strategies have been shown to decrease mortality from the disease. Furthermore, no reliable circulating biomarkers of lung cancer have been identified that allow early diagnosis. With the advent of gene targeting technology, new genetically engineered mouse models of lung cancer closely recapitulate the pathobiology of human disease. These mouse models have enabled novel approaches to early detection, including the identification of cancer-associated serum markers using proteomic technologies and the development of new molecular imaging tools. The application of innovative technologies to accurate mouse models promises to accelerate the discovery of new molecular targets and imaging biomarkers for the early detection of lung cancer.

Authors
Shaw, AT; Kirsch, DG; Jacks, T
MLA Citation
Shaw, AT, Kirsch, DG, and Jacks, T. "Future of early detection of lung cancer: the role of mouse models." Clinical cancer research : an official journal of the American Association for Cancer Research 11.13 Pt 2 (July 1, 2005). (Review)
Source
scopus
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
11
Issue
13 Pt 2
Publish Date
2005

Future of early detection of lung cancer: the role of mouse models.

Early detection represents one of the most promising approaches to improving lung cancer survival. To date, no screening strategies have been shown to decrease mortality from the disease. Furthermore, no reliable circulating biomarkers of lung cancer have been identified that allow early diagnosis. With the advent of gene targeting technology, new genetically engineered mouse models of lung cancer closely recapitulate the pathobiology of human disease. These mouse models have enabled novel approaches to early detection, including the identification of cancer-associated serum markers using proteomic technologies and the development of new molecular imaging tools. The application of innovative technologies to accurate mouse models promises to accelerate the discovery of new molecular targets and imaging biomarkers for the early detection of lung cancer.

Authors
Shaw, AT; Kirsch, DG; Jacks, T
MLA Citation
Shaw, AT, Kirsch, DG, and Jacks, T. "Future of early detection of lung cancer: the role of mouse models." Clin Cancer Res 11.13 Pt 2 (July 1, 2005): 4999s-5003s. (Review)
PMID
16000603
Source
pubmed
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
11
Issue
13 Pt 2
Publish Date
2005
Start Page
4999s
End Page
5003s
DOI
10.1158/1078-0432.CCR-05-9005

Proton radiotherapy for Hodgkin's disease in the sacrum.

Authors
Kirsch, DG; Ebb, DH; Hernandez, AH; Tarbell, NJ
MLA Citation
Kirsch, DG, Ebb, DH, Hernandez, AH, and Tarbell, NJ. "Proton radiotherapy for Hodgkin's disease in the sacrum." Lancet Oncol 6.7 (July 2005): 532-533.
PMID
15992703
Source
pubmed
Published In
The Lancet Oncology
Volume
6
Issue
7
Publish Date
2005
Start Page
532
End Page
533
DOI
10.1016/S1470-2045(05)70248-5

Brain metastases in patients with breast cancer: new horizons.

Brain metastases occur in as many as one third of patients with disseminated breast cancer. In this article, we discuss various presentations of brain metastases from breast cancer and review evidence that supports different treatment options. Because no prospective, randomized, controlled studies, to our knowledge, have focused solely on patients with brain metastases from breast cancer, we will first review retrospective studies of patients with brain metastases from breast cancer. Randomized studies of patients with brain metastases caused by multiple primary cancers will also be examined, and the conclusions from these studies will be extrapolated to patients with breast cancer. Because brain metastases from breast cancer occur in a variety of different clinical settings, ranging from a single metastasis without extensive extracranial disease to multiple brain metastases with widespread extracranial disease, treatment approaches must be tailored to the specific circumstances of each patient. For different clinical scenarios, neurosurgical resection, radiosurgery, and/or whole-brain radiation therapy may be appropriate treatment options. For patients with brain metastases from breast cancer that overexpresses HER2/neu, trastuzumab could alter the natural history of the non-central nervous system (CNS) disease. Therefore, HER2 status could also influence the treatment of brain metastases from breast cancer. Given the prevalence of brain metastases in patients with metastatic breast cancer in contemporary series, the rationale for clinical trials of CNS screening and prophylactic cranial irradiation will be discussed.

Authors
Kirsch, DG; Loeffler, JS
MLA Citation
Kirsch, DG, and Loeffler, JS. "Brain metastases in patients with breast cancer: new horizons." Clin Breast Cancer 6.2 (June 2005): 115-124. (Review)
PMID
16001989
Source
pubmed
Published In
Clinical Breast Cancer
Volume
6
Issue
2
Publish Date
2005
Start Page
115
End Page
124
DOI
10.3816/CBC.2005.n.013

Survival after brain metastases from breast cancer in the trastuzumab era.

Authors
Kirsch, DG; Ledezma, CJ; Mathews, CS; Bhan, AK; Ancukiewicz, M; Hochberg, FH; Loeffler, JS
MLA Citation
Kirsch, DG, Ledezma, CJ, Mathews, CS, Bhan, AK, Ancukiewicz, M, Hochberg, FH, and Loeffler, JS. "Survival after brain metastases from breast cancer in the trastuzumab era." J Clin Oncol 23.9 (March 20, 2005): 2114-2116. (Letter)
PMID
15774813
Source
pubmed
Published In
Journal of Clinical Oncology
Volume
23
Issue
9
Publish Date
2005
Start Page
2114
End Page
2116
DOI
10.1200/JCO.2005.05.249

Mouse models of human non-small-cell lung cancer: raising the bar.

Lung cancer is a devastating disease that presents a challenge to basic research to provide new steps toward therapeutic advances. The cell-type-specific responses to oncogenic mutations that initiate and regulate lung cancer remain poorly defined. A better understanding of the relevant signaling pathways and mechanisms that control therapeutic outcome could also provide new insight. Improved conditional mouse models are now available as tools to improve the understanding of the cellular and molecular origins of adenocarcinoma. These models have already proven their utility in proof-of-principle experiments with new technologies including genomics and imaging. Integrated thinking to apply technological advances while using the appropriate mouse model is likely to facilitate discoveries that will significantly improve lung cancer detection and intervention.

Authors
Kim, CFB; Jackson, EL; Kirsch, DG; Grimm, J; Shaw, AT; Lane, K; Kissil, J; Olive, KP; Sweet-Cordero, A; Weissleder, R; Jacks, T
MLA Citation
Kim, CFB, Jackson, EL, Kirsch, DG, Grimm, J, Shaw, AT, Lane, K, Kissil, J, Olive, KP, Sweet-Cordero, A, Weissleder, R, and Jacks, T. "Mouse models of human non-small-cell lung cancer: raising the bar." Cold Spring Harb Symp Quant Biol 70 (2005): 241-250. (Review)
PMID
16869760
Source
pubmed
Published In
Cold Spring Harbor Laboratory: Symposia on Quantitative Biology
Volume
70
Publish Date
2005
Start Page
241
End Page
250
DOI
10.1101/sqb.2005.70.037

Treating brain metastases: current approaches and future directions.

Brain metastases frequently present with neurologic signs or symptoms in a patient with a history of cancer. The finding of a brain metastasis is usually associated with terminal disease. However, patients with brain metastases are a heterogeneous group. Therefore, the treatment of brain metastases must be tailored to each individual patient. In this article, which patients with brain metastases benefit from surgical resection, radiosurgery and whole-brain radiation therapy are reviewed. Reports of treating patients with brain metastases with chemotherapy are also reviewed and data that supports prophylactic treatment of the brain for select patients is discussed. This review aims to provide a framework for treating patients with different presentations of brain metastases and to highlight important avenues for future research.

Authors
Kirsch, DG; Loeffler, JS
MLA Citation
Kirsch, DG, and Loeffler, JS. "Treating brain metastases: current approaches and future directions." Expert Rev Neurother 4.6 (November 2004): 1015-1022. (Review)
PMID
15853528
Source
pubmed
Published In
Expert Review of Neurotherapeutics
Volume
4
Issue
6
Publish Date
2004
Start Page
1015
End Page
1022
DOI
10.1586/14737175.4.6.1015

New technologies in radiation therapy for pediatric brain tumors: the rationale for proton radiation therapy.

BACKGROUND: Pediatric brain tumors are frequently treated with radiation therapy and often cured. The long-term side effects of treatment with high-energy X-rays (photons) can be substantial. Proton radiation therapy may limit these late effects. PROCEDURE: The physical difference between photon and proton irradiation is compared. The clinical benefits of the superior physical properties of proton beam radiation therapy are explained for children with brain tumors. RESULTS: At biologically equivalent doses, proton radiation therapy offers tumor control similar to photon radiation therapy. The superior physical properties of proton beams make this mode of radiation therapy less likely to cause late effects. CONCLUSIONS: For many children with brain tumors, proton beam radiation therapy may limit the late effects of radiation therapy and therefore offer an advantage over techniques using photons.

Authors
Kirsch, DG; Tarbell, NJ
MLA Citation
Kirsch, DG, and Tarbell, NJ. "New technologies in radiation therapy for pediatric brain tumors: the rationale for proton radiation therapy." Pediatr Blood Cancer 42.5 (May 2004): 461-464. (Review)
PMID
15049021
Source
pubmed
Published In
Pediatric Blood & Cancer
Volume
42
Issue
5
Publish Date
2004
Start Page
461
End Page
464
DOI
10.1002/pbc.10471

Conformal radiation therapy for childhood CNS tumors.

Radiation therapy plays a central role in the management of many childhood brain tumors. By combining advances in brain tumor imaging with technology to plan and deliver radiation therapy, pediatric brain tumors can be treated with conformal radiation therapy. Through conformal radiation therapy, the radiation dose is targeted to the tumor, which can minimize the dose to normal brain structures. Therefore, by limiting the radiation dose to normal brain tissues, conformal radiation therapy offers the possibility of limiting the long-term side effects of brain irradiation.In this review, we describe different approaches to conformal radiation therapy for pediatric central nervous system tumors including: A) three-dimensional conformal radiation therapy; B) stereotactic radiation therapy with arc photons; C) intensity-modulated radiation therapy; and D) proton beam radiation therapy. We discuss the merits and limitations of these techniques and describe clinical scenarios in which conformal radiation therapy offers advantages over conventional radiation therapy for treating pediatric brain tumors.

Authors
Kirsch, DG; Tarbell, NJ
MLA Citation
Kirsch, DG, and Tarbell, NJ. "Conformal radiation therapy for childhood CNS tumors." Oncologist 9.4 (2004): 442-450. (Review)
PMID
15266097
Source
pubmed
Published In
The oncologist
Volume
9
Issue
4
Publish Date
2004
Start Page
442
End Page
450

The controversy of adjuvant whole-brain radiation therapy

Authors
Kirsch, DG; Loeffler, JS
MLA Citation
Kirsch, DG, and Loeffler, JS. "The controversy of adjuvant whole-brain radiation therapy." Journal of Supportive Oncology 2.5 (2004): 412-414.
Source
scival
Published In
Journal of Supportive Oncology
Volume
2
Issue
5
Publish Date
2004
Start Page
412
End Page
414

Targeting HER2 in brain metastases from breast cancer.

Authors
Kirsch, DG; Hochberg, FH
MLA Citation
Kirsch, DG, and Hochberg, FH. "Targeting HER2 in brain metastases from breast cancer." Clin Cancer Res 9.15 (November 15, 2003): 5435-5436.
PMID
14654521
Source
pubmed
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
9
Issue
15
Publish Date
2003
Start Page
5435
End Page
5436

Wegener's granulomatosis with cardiac involvement masquerading as Lyme disease.

Cardiac conduction disease is an infrequent complication of Wegener's granulomatosis (WG). We describe a case demonstrating an association between WG and complete atrioventricular dissociation. This manifestation was initially interpreted as Lyme disease based on these cardiac findings, arthritis, myalgias and positive Lyme serology. The clinical overlap between these disorders and the appropriate use of respective serologies is discussed.

Authors
Kouba, DJ; Kirsch, DG; Mimouni, D; Nousari, CH
MLA Citation
Kouba, DJ, Kirsch, DG, Mimouni, D, and Nousari, CH. "Wegener's granulomatosis with cardiac involvement masquerading as Lyme disease." Clin Exp Rheumatol 21.5 (September 2003): 647-649.
PMID
14611118
Source
pubmed
Published In
Clinical and experimental rheumatology
Volume
21
Issue
5
Publish Date
2003
Start Page
647
End Page
649

Laparoscopic versus open fundoplication in infants.

BACKGROUND: Laparoscopic esophagogastric fundoplication is an effective treatment for severe gastroesophageal reflux disease (GERD), although its role in the very young is still largely undetermined. We review our surgical outcome in infants with severe GERD, comparing laparoscopic (LNF) with open (ONF) Nissen fundoplication. METHODS: This study reviewed 55 consecutive Nissen fundoplications performed for GERD on infants less than 1 year old at our institution between January 1996 and June 2000. The follow-up period for LNF averaged 14.2 months (range, 3.3-42 months), as compared with 16.5 months (range, 1-37.1 months) for ONF (p was not significant, t-test). Surgical outcome was compared in terms of the following parameters: average operative time, times to initiation and completion of feeding schedule, postoperative complications, and recurrence rates. RESULTS: For the study, 53 infants were divided into two groups: LNF (n = 39; 73.6%) and ONF (n = 14; 26.4%). The average operating time for LNF was 120 +/- 24 min (range, 60-195 min), as compared with 91 +/- 21 min (range, 60-135 min) for ONF (p < 0.05, t-test). Time to initiation of postoperative feeding schedule was 1.3 +/- 0.3 days for LNF, as compared with 3 +/- 0.9 days for ONF (p < 0.05, t-test). Full feedings were reached in 1.7 +/- 0.6 days for LNF, as compared with 1.3 +/- 0.9 for ONF (p was not significant, t-test). During the short-term follow-up period, recurrent reflux developed in 2/14 ONF patients (14.3%) as compared with 1/39 LNF patients (2.6%) (p < 0.05). CONCLUSIONS: We conclude that in addition to sparing infants the morbidity of celiotomy, laparoscopic Nissen fundoplication had a surgical outcome comparable to that of traditional open fundoplication in infants with severe GERD. Importantly, resumption of goal nutritional regimens was equally efficient in both groups.

Authors
Somme, S; Rodriguez, JA; Kirsch, DG; Liu, DC
MLA Citation
Somme, S, Rodriguez, JA, Kirsch, DG, and Liu, DC. "Laparoscopic versus open fundoplication in infants." Surg Endosc 16.1 (January 2002): 54-56.
PMID
11961605
Source
pubmed
Published In
Surgical Endoscopy
Volume
16
Issue
1
Publish Date
2002
Start Page
54
End Page
56
DOI
10.1007/s00464-001-8147-1

Caspase-3-dependent cleavage of Bcl-2 promotes release of cytochrome c.

Caspases are cysteine proteases that mediate apoptosis by proteolysis of specific substrates. Although many caspase substrates have been identified, for most substrates the physiologic caspase(s) required for cleavage is unknown. The Bcl-2 protein, which inhibits apoptosis, is cleaved at Asp-34 by caspases during apoptosis and by recombinant caspase-3 in vitro. In the present study, we show that endogenous caspase-3 is a physiologic caspase for Bcl-2. Apoptotic extracts from 293 cells cleave Bcl-2 but not Bax, even though Bax is cleaved to an 18-kDa fragment in SK-NSH cells treated with ionizing radiation. In contrast to Bcl-2, cleavage of Bax was only partially blocked by caspase inhibitors. Inhibitor profiles indicate that Bax may be cleaved by more than one type of noncaspase protease. Immunodepletion of caspase-3 from 293 extracts abolished cleavage of Bcl-2 and caspase-7, whereas immunodepletion of caspase-7 had no effect on Bcl-2 cleavage. Furthermore, MCF-7 cells, which lack caspase-3 expression, do not cleave Bcl-2 following staurosporine-induced cell death. However, transient transfection of caspase-3 into MCF-7 cells restores Bcl-2 cleavage after staurosporine treatment. These results demonstrate that in these models of apoptosis, specific cleavage of Bcl-2 requires activation of caspase-3. When the pro-apoptotic caspase cleavage fragment of Bcl-2 is transfected into baby hamster kidney cells, it localizes to mitochondria and causes the release of cytochrome c into the cytosol. Therefore, caspase-3-dependent cleavage of Bcl-2 appears to promote further caspase activation as part of a positive feedback loop for executing the cell.

Authors
Kirsch, DG; Doseff, A; Chau, BN; Lim, DS; de Souza-Pinto, NC; Hansford, R; Kastan, MB; Lazebnik, YA; Hardwick, JM
MLA Citation
Kirsch, DG, Doseff, A, Chau, BN, Lim, DS, de Souza-Pinto, NC, Hansford, R, Kastan, MB, Lazebnik, YA, and Hardwick, JM. "Caspase-3-dependent cleavage of Bcl-2 promotes release of cytochrome c." J Biol Chem 274.30 (July 23, 1999): 21155-21161.
PMID
10409669
Source
pubmed
Published In
The Journal of biological chemistry
Volume
274
Issue
30
Publish Date
1999
Start Page
21155
End Page
21161

Defective potassium currents in ataxia telangiectasia fibroblasts.

Similarities exist between the progressive cerebellar ataxia in ataxia telangiectasia (AT) patients and a number of neurodegenerative diseases in both mouse and man involving specific mutations in ion channels and/or ion channel activity. These relationships led us to investigate the possibility of defective ion channel activity in AT cells. We examined changes in the membrane potential of AT fibroblasts in response to extracellular cation addition and found that the ability of AT fibroblasts to depolarize in response to increasing concentrations of extracellular K+ is significantly reduced when compared with control fibroblasts. Electrophysiological measurements performed with a number of AT cell lines, as well as two matched sets of primary AT fibroblast cultures, reveal that outward rectifier K+ currents are largely absent in AT fibroblasts in comparison with control cells. These K+ current defects can be corrected in AT fibroblasts transfected with the full-length ATM cDNA. These data implicate, for the first time, a role for ATM in the regulation of K+ channel activity and membrane potential.

Authors
Rhodes, N; D'Souza, T; Foster, CD; Ziv, Y; Kirsch, DG; Shiloh, Y; Kastan, MB; Reinhart, PH; Gilmer, TM
MLA Citation
Rhodes, N, D'Souza, T, Foster, CD, Ziv, Y, Kirsch, DG, Shiloh, Y, Kastan, MB, Reinhart, PH, and Gilmer, TM. "Defective potassium currents in ataxia telangiectasia fibroblasts." Genes Dev 12.23 (December 1, 1998): 3686-3692.
PMID
9851975
Source
pubmed
Published In
Genes & development
Volume
12
Issue
23
Publish Date
1998
Start Page
3686
End Page
3692

Tumor-suppressor p53: implications for tumor development and prognosis.

The p53 protein plays a central role in modulating cellular responses to cytotoxic stresses by contributing to both cell-cycle arrest and programmed cell death. Loss of p53 function during tumorigenesis can lead to inappropriate cell growth, increased cell survival, and genetic instability. p53 gene mutations occur in approximately half of all malignancies from a wide range of human tumors. In some tumor types, these p53 mutations are associated with poor prognosis and treatment failure. Based on these insights, new approaches are being developed to prevent, diagnose, and treat cancer.

Authors
Kirsch, DG; Kastan, MB
MLA Citation
Kirsch, DG, and Kastan, MB. "Tumor-suppressor p53: implications for tumor development and prognosis." J Clin Oncol 16.9 (September 1998): 3158-3168. (Review)
PMID
9738588
Source
pubmed
Published In
Journal of Clinical Oncology
Volume
16
Issue
9
Publish Date
1998
Start Page
3158
End Page
3168
DOI
10.1200/JCO.1998.16.9.3158

ATM binds to beta-adaptin in cytoplasmic vesicles.

Inherited mutations in the ATM gene lead to a complex clinical phenotype characterized by neuronal degeneration, oculocutaneous telangiectasias, immune dysfunction, and cancer predisposition. Using the yeast two-hybrid system, we demonstrate that ataxia telangiectasia mutated (ATM) binds to beta-adaptin, one of the components of the AP-2 adaptor complex, which is involved in clathrin-mediated endocytosis of receptors. The interaction between ATM and beta-adaptin was confirmed in vitro, and coimmunoprecipitation and colocalization studies show that the proteins also associate in vivo. ATM also interacts in vitro with beta-NAP, a neuronal-specific beta-adaptin homolog that was identified as an autoantigen in a patient with cerebellar degeneration. Our data describing the association of ATM with beta-adaptin in vesicles indicate that ATM may play a role in intracellular vesicle and/or protein transport mechanisms.

Authors
Lim, DS; Kirsch, DG; Canman, CE; Ahn, JH; Ziv, Y; Newman, LS; Darnell, RB; Shiloh, Y; Kastan, MB
MLA Citation
Lim, DS, Kirsch, DG, Canman, CE, Ahn, JH, Ziv, Y, Newman, LS, Darnell, RB, Shiloh, Y, and Kastan, MB. "ATM binds to beta-adaptin in cytoplasmic vesicles." Proc Natl Acad Sci U S A 95.17 (August 18, 1998): 10146-10151.
PMID
9707615
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
95
Issue
17
Publish Date
1998
Start Page
10146
End Page
10151

Modulation of cell death by Bcl-XL through caspase interaction.

The caspases are cysteine proteases that have been implicated in the execution of programmed cell death in organisms ranging from nematodes to humans. Many members of the Bcl-2 family, including Bcl-XL, are potent inhibitors of programmed cell death and inhibit activation of caspases in cells. Here, we report a direct interaction between caspases and Bcl-XL. The loop domain of Bcl-XL is cleaved by caspases in vitro and in cells induced to undergo apoptotic death after Sindbis virus infection or interleukin 3 withdrawal. Mutation of the caspase cleavage site in Bcl-XL in conjunction with a mutation in the BH1 homology domain impairs the death-inhibitory activity of Bcl-XL, suggesting that interaction of Bcl-XL with caspases may be an important mechanism of inhibiting cell death. However, once Bcl-XL is cleaved, the C-terminal fragment of Bcl-XL potently induces apoptosis. Taken together, these findings indicate that the recognition/cleavage site of Bcl-XL may facilitate protection against cell death by acting at the level of caspase activation and that cleavage of Bcl-XL during the execution phase of cell death converts Bcl-XL from a protective to a lethal protein.

Authors
Clem, RJ; Cheng, EH; Karp, CL; Kirsch, DG; Ueno, K; Takahashi, A; Kastan, MB; Griffin, DE; Earnshaw, WC; Veliuona, MA; Hardwick, JM
MLA Citation
Clem, RJ, Cheng, EH, Karp, CL, Kirsch, DG, Ueno, K, Takahashi, A, Kastan, MB, Griffin, DE, Earnshaw, WC, Veliuona, MA, and Hardwick, JM. "Modulation of cell death by Bcl-XL through caspase interaction." Proc Natl Acad Sci U S A 95.2 (January 20, 1998): 554-559.
PMID
9435230
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
95
Issue
2
Publish Date
1998
Start Page
554
End Page
559

Conversion of Bcl-2 to a Bax-like death effector by caspases.

Caspases are a family of cysteine proteases implicated in the biochemical and morphological changes that occur during apoptosis (programmed cell death). The loop domain of Bcl-2 is cleaved at Asp34 by caspase-3 (CPP32) in vitro, in cells overexpressing caspase-3, and after induction of apoptosis by Fas ligation and interleukin-3 withdrawal. The carboxyl-terminal Bcl-2 cleavage product triggered cell death and accelerated Sindbis virus-induced apoptosis, which was dependent on the BH3 homology and transmembrane domains of Bcl-2. Inhibitor studies indicated that cleavage of Bcl-2 may further activate downstream caspases and contribute to amplification of the caspase cascade. Cleavage-resistant mutants of Bcl-2 had increased protection from interleukin-3 withdrawal and Sindbis virus-induced apoptosis. Thus, cleavage of Bcl-2 by caspases may ensure the inevitability of cell death.

Authors
Cheng, EH; Kirsch, DG; Clem, RJ; Ravi, R; Kastan, MB; Bedi, A; Ueno, K; Hardwick, JM
MLA Citation
Cheng, EH, Kirsch, DG, Clem, RJ, Ravi, R, Kastan, MB, Bedi, A, Ueno, K, and Hardwick, JM. "Conversion of Bcl-2 to a Bax-like death effector by caspases." Science 278.5345 (December 12, 1997): 1966-1968.
PMID
9395403
Source
pubmed
Published In
Science
Volume
278
Issue
5345
Publish Date
1997
Start Page
1966
End Page
1968

p53 does not repress hypoxia-induced transcription of the vascular endothelial growth factor gene.

Hypoxia-induced neovascularization mediated by vascular endothelial growth factor (VEGF) contributes to tumor progression. Based on its effects when overexpressed in transient transfection assays, p53 has been proposed to repress VEGF transcription. To investigate this hypothesis, we have analyzed endogenous VEGF mRNA levels in Hep3B cells stably expressing an inducible p53-estrogen receptor fusion protein and in irradiated RKO cells expressing endogenous wild-type p53. In both cell lines, VEGF mRNA levels increased in response to hypoxia, either in the presence or absence of functional p53. Our data provide no evidence for a causal relationship between the loss of p53 activity and increased VEGF expression that is observed during tumor progression. Studies that attribute repressor functions to p53 based on analysis of cells transiently overexpressing this protein should be interpreted cautiously.

Authors
Agani, F; Kirsch, DG; Friedman, SL; Kastan, MB; Semenza, GL
MLA Citation
Agani, F, Kirsch, DG, Friedman, SL, Kastan, MB, and Semenza, GL. "p53 does not repress hypoxia-induced transcription of the vascular endothelial growth factor gene." Cancer Res 57.20 (October 15, 1997): 4474-4477.
PMID
9377555
Source
pubmed
Published In
Cancer Research
Volume
57
Issue
20
Publish Date
1997
Start Page
4474
End Page
4477

Cell cycle and cell death after DNA damaye

A variety of cellular responses to DNA damage influence cellular fate, such as whether heritable genetic alterations are passed on to daughter cells and whether the cell survives the damaging insult. The p53 and ATM gene products play critical roles in modulating perturbations in cell cycle progression and in programmed cell death after DNA damage. Posttranscriptional increases in p53 protein levels after introduction of DNA strand breaks can lead to either arrest of the cell cycle in G l or in apoptotic death of the cell. Loss of p53 function may be selected for during tumorigenesis to reduce programmed cell death, but p53 mutations may then contribute further to tumor progression by the additional mechanism of enhanced genetic instability. Growth factor signalling pathways can inhibit the DNA damage-induced apoptotic death and may provide a novel target for enhancing tumor kill after chemo/radiation therapy. DNA damage induces a specific phosphorylation change in p53 protein which may contribute to its induction. The ATM protein is homologous to the yeast DNA damage response proteins rad3, tell, and mecl and is required for normal induction of p53 after ionizing irradiation. ATM dysfunction leads to radiosensitivity, enhanced chromosomal breakage, and loss of cell cycle checkpoints. Identification of dominant-negative and complementing fragments of ATM has facilitated investigations into the mechanisms of ATM function.

Authors
Kastan, MB; Morgan, SE; Siliciano, J; Kirsch, D; Dennis, P; Canman, CE
MLA Citation
Kastan, MB, Morgan, SE, Siliciano, J, Kirsch, D, Dennis, P, and Canman, CE. "Cell cycle and cell death after DNA damaye." FASEB Journal 11.9 (1997): A878-.
Source
scival
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
11
Issue
9
Publish Date
1997
Start Page
A878

GABP and PU.1 compete for binding, yet cooperate to increase CD18 (beta 2 leukocyte integrin) transcription.

CD18 (beta 2 leukocyte integrin) is a leukocyte-specific adhesion molecule that plays a crucial role in immune and inflammatory responses. A 79-nucleotide fragment of the CD18 promoter is sufficient to direct myeloid transcription. The CD18 promoter is bound by the B lymphocyte- and myeloid-restricted ets factor, PU.1, and disruption of the PU.1-binding sites significantly reduces promoter activity. However, PU.1 alone cannot fully account for the leukocyte-specific and myeloid-inducible transcription of CD18. We identified a ubiquitously expressed nuclear protein complex of extremely low electrophoretic mobility that also binds to this region of the CD18 promoter. This binding complex is a heterotetramer composed of GABP alpha, and ets factor, and GABP beta, a subunit with homology to Drosophila Notch. GABP alpha competes with the lineage restricted factor, PU.1, for the same critical CD18 ets sites. The CD18 promoter is activated in myeloid cells by transfection with both GABP alpha and GABP beta together, but not by either factor alone. Transfection of non-hematopoietic cells with the two GABP subunits together with PU.1 is sufficient to activate CD18 transcription in otherwise non-permissive cells. Thus, GABP and PU.1 compete for the same binding sites but cooperate to activate CD18 transcription.

Authors
Rosmarin, AG; Caprio, DG; Kirsch, DG; Handa, H; Simkevich, CP
MLA Citation
Rosmarin, AG, Caprio, DG, Kirsch, DG, Handa, H, and Simkevich, CP. "GABP and PU.1 compete for binding, yet cooperate to increase CD18 (beta 2 leukocyte integrin) transcription." J Biol Chem 270.40 (October 6, 1995): 23627-23633.
PMID
7559529
Source
pubmed
Published In
The Journal of biological chemistry
Volume
270
Issue
40
Publish Date
1995
Start Page
23627
End Page
23633

Does the intestinal microflora synthesize pyrroloquinoline quinone?

Pyrroloquinoline quinone (PQQ) functions as a cofactor for prokaryotic oxidoreductases, such as methanol dehydrogenase and glucose dehydrogenase. When chemically-defined diets without PQQ are fed to animals, lathyritic changes are observed. In previous studies, it was assumed that PQQ was produced by the intestinal microflora; consequently, antibiotics were routinely added to diets. In the present study this assumption is tested further in mice by: (i) examining the effects of dietary antibiotics on fecal PQQ excretion, (ii) isolating the intestinal flora to identify bacteria known to synthesize PQQ and (iii) determining in vitro if the intestinal microflora synthesizes PQQ from radio-chemically labeled precursors. The results of these experiments indicate that little if any PQQ is synthesized by the intestinal microflora. Rather, when PQQ is present in the intestine, the diet is a more obvious source.

Authors
Smidt, CR; Bean-Knudsen, D; Kirsch, DG; Rucker, RB
MLA Citation
Smidt, CR, Bean-Knudsen, D, Kirsch, DG, and Rucker, RB. "Does the intestinal microflora synthesize pyrroloquinoline quinone?." Biofactors 3.1 (January 1991): 53-59.
PMID
1647778
Source
pubmed
Published In
BioFactors
Volume
3
Issue
1
Publish Date
1991
Start Page
53
End Page
59

Selenate reduction by a Pseudomonas species: a new mode of anaerobic respiration.

The high levels of selenium (selenate, selenite) in agricultural drainage water in the San Joaquin Valley of California, which have led to environmental problems, might be lowered if the selenate/selenite could be reduced to elemental insoluble selenium. Two organisms have been newly isolated which do this in anaerobic coculture. One, a strictly anaerobic, Gram-positive rod, reduces selenite to elemental selenium. The other, a Pseudomonas species, was shown to respire selenate to selenite. Cells grown anaerobically in Minimal Medium on acetate plus selenate oxidized 14C-acetate to 14CO2 with concomitant reduction of selenate to selenite and small amounts of elemental selenium.

Authors
Macy, JM; Michel, TA; Kirsch, DG
MLA Citation
Macy, JM, Michel, TA, and Kirsch, DG. "Selenate reduction by a Pseudomonas species: a new mode of anaerobic respiration." FEMS Microbiol Lett 52.1-2 (October 1, 1989): 195-198.
PMID
2513248
Source
pubmed
Published In
Fems Microbiology Letters
Volume
52
Issue
1-2
Publish Date
1989
Start Page
195
End Page
198

Application of isolated hepatocytes to studies of drug metabolism in large food animals.

A definitive hazard assessment of xenobiotics translocated through food animals into edible products such as meat or milk requires a complete analysis of metabolism in food animals. However, large animal metabolism studies present many experimental difficulties. None of several in vitro alternatives such as subcellular fractions has been established as an acceptable predictor of in vivo metabolism. The feasibility of using isolated hepatocytes to predict the metabolism of xenobiotics, both quantitatively and qualitatively, in large ruminant animals (e.g. cattle) is being studied in our laboratory. A procedure was developed for isolating hepatocytes aseptically from the caudate process of the liver which was obtained surgically from 100-125 kg calves. A modified two-step vascular perfusion procedure provides hepatocyte suspensions that are typically greater than or equal to 85% viable and greater than or equal to 1 X 10(7) viable hepatocytes/g of liver (wet wt). Xenobiotic metabolism has been evaluated in suspensions and primary cultures using aldrin epoxidation, ethoxycoumarin O-deethylation, and 7-hydroxycoumarin glucuronidation and sulfation. Metabolic activities are relatively short-lived in suspensions less than or equal to 4 h, but quite stable up to 10 h when cultured on collagen-coated plates in chemically defined medium. Bovine hepatocytes behave similarly in culture to rodent hepatocytes. Although primary culturing of hepatocytes is more difficult than suspensions, primarily due to the asepsis requirements, it is the method of choice for xenobiotic metabolism determinations in isolated hepatocytes of cattle.

Authors
Shull, LR; Kirsch, DG; Lohse, CL; Wisniewski, JA
MLA Citation
Shull, LR, Kirsch, DG, Lohse, CL, and Wisniewski, JA. "Application of isolated hepatocytes to studies of drug metabolism in large food animals." Xenobiotica 17.3 (March 1987): 345-363. (Review)
PMID
3554786
Source
pubmed
Published In
Xenobiotica (Informa)
Volume
17
Issue
3
Publish Date
1987
Start Page
345
End Page
363
DOI
10.3109/00498258709043944

Xenobiotic metabolism in suspensions and primary cultures of isolated hepatocytes prepared from the caudate process of bovine liver.

Isolated hepatocytes were prepared from 100- to 125-kg Holstein male calves (n = 10) by perfusion of the caudate process of the caudate lobe of the liver. The 11th or 12th rib on the right side was resected to provide exposure of the caudate process. Complete postsurgical recovery of the donor from partial lobectomy was confirmed by growth data and serum chemical and hematologic criteria. Hepatocytes were isolated under aseptic conditions, using a 2-step collagenase vascular perfusion procedure. Hepatocyte preparations averaged 85% viability, and the yield averaged 1.2 X 10(7) viable hepatocytes/g of (wet weight) liver. Morphologic characteristics of hepatocytes examined under light and scanning electron microscopy were considered normal, except for occasional surface blebs. Freshly isolated hepatocytes in suspension rapidly decreased in viability and xenobiotic metabolizing capacity (aldrin epoxidation and ethoxycoumarin 0-deethylation and 7-hydroxycoumarin glucuronidation and sulfation), and hepatocytes surviving the initial 2 to 3 hours appeared to undergo repair. As an alternative, primary monolayer cultures on collagen-coated plates were evaluated. Hepatocytes attached to the collagen surface within 4 hours and appeared flattened by 12 hours. Although metabolic activity decreased about 30% over 8 hours in culture, the pattern of ethoxycoumarin metabolites was relatively constant. It was not determined to what extent the apparent loss of metabolic capacity was caused by hepatocyte detachment from the collagen surface. Although complicated by the requirement for asepsis, primary cultures were superior to suspensions for xenobiotic metabolism studies in cattle.

Authors
Shull, LR; Kirsch, DG; Lohse, CL; Carlson, GP; Doody, LA; Wisniewski, JA
MLA Citation
Shull, LR, Kirsch, DG, Lohse, CL, Carlson, GP, Doody, LA, and Wisniewski, JA. "Xenobiotic metabolism in suspensions and primary cultures of isolated hepatocytes prepared from the caudate process of bovine liver." Am J Vet Res 47.9 (September 1986): 2043-2052.
PMID
3767111
Source
pubmed
Published In
American journal of veterinary research
Volume
47
Issue
9
Publish Date
1986
Start Page
2043
End Page
2052
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