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Li, Chuan-Yuan

Overview:

Dr. Li is the Vice Chair for Research in the Dept. of Dermatology. Some of the areas that his laboratory conducts research on include:
•Tumor response to therapy, with special emphasis on skin cancer such as melanoma and squamous cell carcinoma where current treatment outcomes are dismal;
•Stem cell and regenerative medicine, we will conduct research to investigate novel mechanisms of stem cell biology so that knowledge gained can be translated into regenerative medicine;
•Mechanisms of carcinogenesis, with emphasis on skin cancers, so that better strategies could be devised to prevent and treat these cancers.

Within these broad areas we have different ongoing research projects. Examples of some of the research projects include:

Unconventional roles of caspases in tumor response to chemotherapy or radiotherapy. A recent area of our laboratory has been the relationship of cell death and repopulation in tumors undergoing radiation and chemotherapy. In our studies, we discovered that cell death is a key trigger for tumor cell repopulation in radiation and chemotherapy. Unexpectedly, caspase 3, which is an executioner in cell death, positively regulate paracrine signaling from dying cells to stimulate proliferation of surviving tumor cells. Furthermore, we found that higher levels of pretreat caspase 3 activation is correlated with worse outcome in head and neck and breast cancers. This is again quite unexpected and contrary to established paradigm. We are currently actively studying the relevance of this mechanism in other malignancies including melanoma. We believe such studies will not only yield promising novel treatments for cancer but also new biomarkers of diagnostic or prognostic values.

Positive roles of apoptosis in wound healing and tissue regeneration. Another area of our research is the relationship between apoptosis and wound healing/tissue regeneration. In our recent research we discovered that cellular apoptosis, in particular, apoptotic caspases 3&7, play key roles in promoting skin wound healing and tissue regeneration. We named this pathway the “Phoenix Rising” pathway for wound healing and tissue regeneration. We are actively studying this mechanism with the hope that knowledge gained could be used for regenerative medicine.

Molecular factors involved in stem cell biology regulation and trans-differentiation. Recently our lab started to investigate molecular mechanisms involved in the maintenance and self-renewal of stem cells. Our efforts led to the discovery that caspases 8&3 play critical roles in the induction of pluripotent stem cells from human fibroblasts. We are in the process of dissecting additional roles of caspases in embryonic stem cells.

Direct reprogramming of one differentiated cell type into another differentiated cell type. Recently, we have been able to directly reprogram human fibroblast cells into dopaminergic neurons, which have great potential in Parksinson’s Disease. We are actively pursuing similar studies to reprogram skin fibroblasts into various cells of interest, including other skin cells, through direct reprogramming.

Positions:

Professor of Dermatology

Dermatology
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

Education:

B.S. 1987

B.S. — Chinese Academy of Sciences (China)

D.Sc. 1992

D.Sc. — Harvard University

Grants:

Necroptotic genes in cancer cellular response to radiation

Administered By
Dermatology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
March 13, 2017
End Date
February 28, 2022

Organization and Function of Cellular Structure

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1975
End Date
June 30, 2020

Exploring BCL-XL addiction in pancreatic ductal adenocarcinoma

Administered By
Pharmacology & Cancer Biology
AwardedBy
National Institutes of Health
Role
Co-Sponsor
Start Date
April 01, 2016
End Date
March 31, 2019

Pro-oncogenic roles of apoptotic caspases

Administered By
Dermatology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
May 08, 2014
End Date
February 28, 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
Collaborator
Start Date
September 15, 2016
End Date
August 31, 2018

Duke University Program in Environmental Health

Administered By
Environmental Sciences and Policy
AwardedBy
National Institute of Environmental Health Sciences
Role
Mentor
Start Date
July 01, 2013
End Date
June 30, 2018

The "Phoenix Rising" pathway of tumor repopulation during radiotherapy

Administered By
Dermatology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 01, 2011
End Date
July 31, 2017

Mechanisms involved in HP802-mediated wound healing

Administered By
Dermatology
AwardedBy
Smith & Nephew, Inc
Role
Principal Investigator
Start Date
May 13, 2014
End Date
May 12, 2016

Molecular Mechanisms of Tumor Response to Cytotoxic Chemotherapy

Administered By
Dermatology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 01, 2011
End Date
April 30, 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

HIF Genes in Head and Neck Cancer Radiotherapy

Administered By
Dermatology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
January 01, 2012
End Date
December 31, 2015

A mechanistic investigation of space radiation-induced carcinogensis

Administered By
Dermatology
AwardedBy
National Aeronautics and Space Administration
Role
Principal Investigator
Start Date
January 01, 2012
End Date
October 31, 2013

Mechanisms of HZE Particle-Induced Genetic Instability/Carcinogenic Transformation

Administered By
Radiation Oncology
AwardedBy
National Aeronautics and Space Administration
Role
Principal Investigator
Start Date
June 01, 2003
End Date
November 30, 2007

Imaging Tumor Hypoxia in a Transgenic Mouse Model

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 16, 2003
End Date
August 31, 2007

Molecular Characterization of the Role of SOD Genes in Mammalian Cellular Response: Low Dose Ionizing Radiation

Administered By
Radiation Oncology
AwardedBy
Department of Energy
Role
Principal Investigator
Start Date
September 01, 2003
End Date
August 31, 2007

Hyperthemia-Mediated Gene Therapy Approach for Cancer

Administered By
Radiation Oncology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
April 02, 1999
End Date
September 01, 2006

Cell Viability in Implantable Diffusion Chambers

Administered By
Surgery, Plastic, Maxillofacial, and Oral Surgery
AwardedBy
National Institutes of Health
Role
Collaborator
Start Date
August 15, 2000
End Date
July 31, 2005
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Publications:

Self-inflicted DNA double-strand breaks sustain tumorigenicity and stemness of cancer cells.

DNA double-strand breaks (DSBs) are traditionally associated with cancer through their abilities to cause chromosomal instabilities or gene mutations. Here we report a new class of self-inflicted DNA DSBs that can drive tumor growth irrespective of their effects on genomic stability. We discover a mechanism through which cancer cells cause DSBs in their own genome spontaneously independent of reactive oxygen species or replication stress. In this mechanism, low-level cytochrome c leakage from the mitochondria leads to sublethal activation of apoptotic caspases and nucleases, which causes DNA DSBs. In response to these spontaneous DNA DSBs, ATM, a key factor involved in DNA damage response, is constitutively activated. Activated ATM leads to activation of transcription factors NF-κB and STAT3, known drivers of tumor growth. Moreover, self-inflicted DNA DSB formation and ATM activation are important in sustaining the stemness of patient-derived glioma cells. In human tumor tissues, elevated levels of activated ATM correlate with poor patient survival. Self-inflicted DNA DSBs therefore are functionally important for maintaining the malignancy of cancer cells.Cell Research advance online publication 24 March 2017; doi: 10.1038/cr.2017.41.

Authors
Liu, X; Li, F; Huang, Q; Zhang, Z; Zhou, L; Deng, Y; Zhou, M; Fleenor, DE; Wang, H; Kastan, MB; Li, C-Y
MLA Citation
Liu, X, Li, F, Huang, Q, Zhang, Z, Zhou, L, Deng, Y, Zhou, M, Fleenor, DE, Wang, H, Kastan, MB, and Li, C-Y. "Self-inflicted DNA double-strand breaks sustain tumorigenicity and stemness of cancer cells." Cell research (March 24, 2017).
PMID
28337983
Source
epmc
Published In
Cell Research
Publish Date
2017
DOI
10.1038/cr.2017.41

Dying glioma cells establish a proangiogenic microenvironment through a caspase 3 dependent mechanism.

Vascular recovery or re-angiogenesis after radiotherapy plays a significant role in tumor recurrence, whereas molecular mechanisms of this process remain elusive. In this work, we found that dying glioma cells promoted post-irradiation angiogenesis through a caspase 3 dependent mechanism. Evidence in vitro and in vivo indicated that caspase 3 inhibition undermined proangiogenic effects of dying glioma cells. Proteolytic inactivation of caspase 3 in glioma cells reduced tumorigenicity. Importantly, we identified that NF-κB/COX-2/PGE2 axis acted as downstream signaling of caspase 3, mediating proangiogenic response after irradiation. Additionally, VEGF-A, regulated by caspase 3 possibly through phosphorylated eIF4E, was recognized as another downstream factor participating in the proangiogenic response. In conclusion, these data demonstrated that caspase 3 in dying glioma cells supported the proangiogenic response after irradiation by governing NF-κB/COX-2/PGE2 axis and p-eIF4E/VEGF-A signaling. While inducing caspase 3 activation has been a generally-adopted notion in cancer therapeutics, our study counterintuitively illustrated that caspase 3 activation in dying glioma cells unfavorably supported post-irradiation angiogenesis. This double-edged role of caspase 3 suggested that taming caspase 3 from the opposite side, not always activating it, may provide novel therapeutic strategies due to restricted post-irradiation angiogenesis.

Authors
Feng, X; Yu, Y; He, S; Cheng, J; Gong, Y; Zhang, Z; Yang, X; Xu, B; Liu, X; Li, C-Y; Tian, L; Huang, Q
MLA Citation
Feng, X, Yu, Y, He, S, Cheng, J, Gong, Y, Zhang, Z, Yang, X, Xu, B, Liu, X, Li, C-Y, Tian, L, and Huang, Q. "Dying glioma cells establish a proangiogenic microenvironment through a caspase 3 dependent mechanism." Cancer letters 385 (January 2017): 12-20.
PMID
27826040
Source
epmc
Published In
Cancer Letters
Volume
385
Publish Date
2017
Start Page
12
End Page
20
DOI
10.1016/j.canlet.2016.10.042

Rapid Reprogramming of Primary Human Astrocytes into Potent Tumor-Initiating Cells with Defined Genetic Factors.

Cancer stem-like cells (CSC) are thought to drive brain cancer, but their cellular and molecular origins remain uncertain. Here, we report the successful generation of induced CSC (iCSC) from primary human astrocytes through the expression of defined genetic factors. Combined transduction of four factors, Myc, Oct-4, p53DD, and Ras, induced efficient transformation of primary human astrocytes into malignant cells with powerful tumor-initiating capabilities. Notably, transplantation of 100 transduced cells into nude mice was sufficient for tumor formation. The cells showed unlimited self-renewal ability with robust telomerase activities. In addition, they expressed typical glioma stem-like cell markers, such as CD133, CD15, and CD90. Moreover, these cells could form spheres in culture and differentiate into neuron-like, astrocyte-like, and oligodendrocyte-like cells. Finally, they also displayed resistance to the widely used brain cancer drug temozolomide. These iCSCs could provide important tools for studies of glioma biology and therapeutics development. Cancer Res; 76(17); 5143-50. ©2016 AACR.

Authors
Li, F; Liu, X; Sampson, JH; Bigner, DD; Li, C-Y
MLA Citation
Li, F, Liu, X, Sampson, JH, Bigner, DD, and Li, C-Y. "Rapid Reprogramming of Primary Human Astrocytes into Potent Tumor-Initiating Cells with Defined Genetic Factors." Cancer research 76.17 (September 2016): 5143-5150.
PMID
27364552
Source
epmc
Published In
Cancer Research
Volume
76
Issue
17
Publish Date
2016
Start Page
5143
End Page
5150
DOI
10.1158/0008-5472.can-16-0171

eIF4E-phosphorylation-mediated Sox2 upregulation promotes pancreatic tumor cell repopulation after irradiation.

Pancreatic cancer is a devastating disease characterized by treatment resistance and high recurrence rate. Repopulation of surviving tumor cells undergoing radiotherapy is one of the most common reasons for recurrence. Our previous studies have discovered a novel mechanism for repopulation after irradiation that activation of caspase-3 in irradiated tumor cells activates PKCδ/p38 axis to transmit proliferation signals promoting repopulation of surviving tumor cells. Here we found Sox2 expression is up-regulated in irradiated pancreatic cancer cells, which played a major role in tumor cell repopulation after irradiation. Over-expression of Sox2 strongly enhanced the growth-stimulating effect of irradiated dying tumor cells on living tumor cells through a paracrine modality. Furthermore, we identified activated eIF4E, which is phosphorylated by MNK1, as a regulator of Sox2 expression after irradiation, and pharmacologic inhibition of eIF4E with CGP57380 and Ribavirin significantly weakened Sox2-mediated tumor cell repopulation. Finally, we showed the activation of caspase 3/PKCδ/p38/MNK1 signal pathway in irradiated pancreatic tumor cells. Together, we showed a novel pathway regulating Sox2 expression and Sox2 may be a promising target to reduce recurrence due to repopulation of surviving tumor cells after radiotherapy.

Authors
Yu, Y; Tian, L; Feng, X; Cheng, J; Gong, Y; Liu, X; Zhang, Z; Yang, X; He, S; Li, C-Y; Huang, Q
MLA Citation
Yu, Y, Tian, L, Feng, X, Cheng, J, Gong, Y, Liu, X, Zhang, Z, Yang, X, He, S, Li, C-Y, and Huang, Q. "eIF4E-phosphorylation-mediated Sox2 upregulation promotes pancreatic tumor cell repopulation after irradiation." Cancer letters 375.1 (May 2016): 31-38.
PMID
26945967
Source
epmc
Published In
Cancer Letters
Volume
375
Issue
1
Publish Date
2016
Start Page
31
End Page
38
DOI
10.1016/j.canlet.2016.02.052

Redefining the roles of apoptotic factors in carcinogenesis.

In a recent study we reported that mammalian cells exposed to stress such as ionizing radiation can survive with activation of caspase-3 or caspase-7. We found that sublethal activation of the executioner caspases promotes chemical- and radiation-induced genetic instability and carcinogenesis, in contrast to their perceived roles as tumor suppressors.

Authors
Liu, X; He, Y; Li, F; Huang, Q; Kato, TA; Hall, RP; Li, C-Y
MLA Citation
Liu, X, He, Y, Li, F, Huang, Q, Kato, TA, Hall, RP, and Li, C-Y. "Redefining the roles of apoptotic factors in carcinogenesis." Molecular & cellular oncology 3.3 (May 2016): e1054550-.
PMID
27314073
Source
epmc
Published In
Molecular & cellular oncology
Volume
3
Issue
3
Publish Date
2016
Start Page
e1054550
DOI
10.1080/23723556.2015.1054550

Roles of caspases in melanoma response to cytotoxic treatment

Authors
Li, F; Li, C
MLA Citation
Li, F, and Li, C. "Roles of caspases in melanoma response to cytotoxic treatment." May 2016.
Source
wos-lite
Published In
Journal of Investigative Dermatology
Volume
136
Issue
5
Publish Date
2016
Start Page
S21
End Page
S21

Key roles of necroptotic factors in promoting tumor growth.

Necroptotic factors are generally assumed to play a positive role in tumor therapy by eliminating damaged tumor cells. Here we show that, contrary to expectation, necroptotic factors RIPK1, RIPK3, and MLKL promote tumor growth. We demonstrate that genetic knockout of necroptotic genes RIPK1, RIPK3, or MLKL in cancer cells significantly attenuated their abilities to grow in an anchorage-independent manner. In addition, they exhibited significantly enhanced radiosensitivity. The knockout cells also showed greatly reduced ability to form tumors in mice. Moreover, necrosulfonamide (NSA), a previously identified chemical inhibitor of necroptosis, could significantly delay tumor growth in a xenograft model. Mechanistically, we show that necroptoic factors play a significant role in maintaining the activity of NF-κB. Finally, we found that high levels of phosphorylated MLKL in human esophageal and colon cancers are associated with poor overall survival. Taken together, we conclude that pro-necroptic factors such as RIPK1, RIPK3, and MLKL may play a role in supporting tumor growth, and MLKL may be a promising target for cancer treatment.

Authors
Liu, X; Zhou, M; Mei, L; Ruan, J; Hu, Q; Peng, J; Su, H; Liao, H; Liu, S; Liu, W; Wang, H; Huang, Q; Li, F; Li, C-Y
MLA Citation
Liu, X, Zhou, M, Mei, L, Ruan, J, Hu, Q, Peng, J, Su, H, Liao, H, Liu, S, Liu, W, Wang, H, Huang, Q, Li, F, and Li, C-Y. "Key roles of necroptotic factors in promoting tumor growth." Oncotarget 7.16 (April 2016): 22219-22233.
PMID
26959742
Source
epmc
Published In
Oncotarget
Volume
7
Issue
16
Publish Date
2016
Start Page
22219
End Page
22233
DOI
10.18632/oncotarget.7924

Caspase 3 in dying tumor cells mediates post-irradiation angiogenesis.

Cytotoxic radiotherapy unfavorably induces tumor cells to generate various proangiogenic substances, promoting post-irradiation angiogenesis (PIA), which is one of major causes of radiotherapy failure. Though several studies have reported some mechanisms behind PIA, they have not yet described the beginning proangiogenic motivator buried in the irradiated microenvironment. In this work, we revealed that dying tumor cells induced by irradiation prompted PIA via a caspase 3 dependent mechanism. Proteolytic inactivation of caspase 3 in dying tumor cells by transducing a dominant-negative version weakened proangiogenic effects in vitro and in vivo. In addition, inhibition of caspase 3 activity suppressed tumor angiogenesis and tumorigenesis in xenograft mouse model. Importantly, we identified vascular endothelial growth factor (VEGF)-A as a downstream proangiogenic factor regulated by caspase 3 possibly through Akt signaling. Collectively, these findings indicated that besides acting as a key executioner in apoptosis, caspase 3 in dying tumor cells may play a central role in driving proangiogenic response after irradiation. Thus, radiotherapy in combination with caspase 3 inhibitors may be a novel promising therapeutic strategy to reduce tumor recurrence due to restrained PIA.

Authors
Feng, X; Tian, L; Zhang, Z; Yu, Y; Cheng, J; Gong, Y; Li, C-Y; Huang, Q
MLA Citation
Feng, X, Tian, L, Zhang, Z, Yu, Y, Cheng, J, Gong, Y, Li, C-Y, and Huang, Q. "Caspase 3 in dying tumor cells mediates post-irradiation angiogenesis." Oncotarget 6.32 (October 2015): 32353-32367.
PMID
26431328
Source
epmc
Published In
Oncotarget
Volume
6
Issue
32
Publish Date
2015
Start Page
32353
End Page
32367
DOI
10.18632/oncotarget.5898

Abstract LB-087: A facilitative role for caspase 3 in promoting genetic instability and carcinogenesis

Authors
LIU, XINJIAN; Li, F; Li, C-Y
MLA Citation
LIU, XINJIAN, Li, F, and Li, C-Y. "Abstract LB-087: A facilitative role for caspase 3 in promoting genetic instability and carcinogenesis." August 1, 2015.
Source
crossref
Published In
Cancer Research
Volume
75
Issue
15 Supplement
Publish Date
2015
Start Page
LB-087
End Page
LB-087
DOI
10.1158/1538-7445.AM2015-LB-087

Increased HMGB1 and cleaved caspase-3 stimulate the proliferation of tumor cells and are correlated with the poor prognosis in colorectal cancer.

Dying tumor cells after irradiation could promote the proliferation of living tumor cells might cause tumor relapse and treatment failure. Our previous study showed that activated caspase-3 after irradiation probably participates in tumor repopulation. In this study, we investigated whether high mobility group box 1(HMGB1) is also involved in tumor repopulation.Colorectal tumor cells were irradiated. The cleaved caspase-3 (CC3) in irradiated tumor cells and HMGB1 in the supernatant of irradiated tumor cells were detected by Western blot. A large number of irradiated colorectal tumor cells (feeder cells) were then co-cultured with a small number of luciferase-labeled living colorectal tumor cells (reporter cells) and proliferation of reporter cells was measured by bioluminescence imaging. The CC3 and HMGB1 protein expression in colorectal tumor and peritumoral tissues were detected by immunohistochemistry and their correlation with prognosis were analyzed.The irradiated colorectal tumor cells underwent apoptosis and necrosis and produced CC3 in tumor cells and HMGB1 in the supernatant of cultured cells. The increased expression of secretory HMGB1 correlated with CC3 level and proliferating cell nuclear antigen (PCNA) after irradiation in vitro. The irradiated dying cells remarkably stimulated living tumor cell proliferation. Interestedly, immunohistochemistry staining showed that positive HMGB1, CC3, and Ki67 expression were significantly higher in colorectal tumor tissues than in peritumoral tissues (p <0.01). The Kaplan-Meier survival analysis revealed that high HMGB1, CC3, and Ki67 levels were significantly associated with poor prognosis (p <0.05, p <0.01). Multivariate analysis using Cox proportional hazards model showed that TNM staging and HMGB1 were independent prognostic factors in patients with colorectal cancer (CRC) (p <0.01, p <0.001).Both apoptotic and necrotic cells could stimulate proliferation of living tumor cells, and the increased expression of CC3 and HMGB1 in tumor cells could be new markers for poor prognosis in colorectal cancer patients.

Authors
Zhang, Z; Wang, M; Zhou, L; Feng, X; Cheng, J; Yu, Y; Gong, Y; Zhu, Y; Li, C; Tian, L; Huang, Q
MLA Citation
Zhang, Z, Wang, M, Zhou, L, Feng, X, Cheng, J, Yu, Y, Gong, Y, Zhu, Y, Li, C, Tian, L, and Huang, Q. "Increased HMGB1 and cleaved caspase-3 stimulate the proliferation of tumor cells and are correlated with the poor prognosis in colorectal cancer." Journal of experimental & clinical cancer research : CR 34 (May 20, 2015): 51-.
PMID
25986235
Source
epmc
Published In
Journal of Experimental and Clinical Cancer Research
Volume
34
Publish Date
2015
Start Page
51
DOI
10.1186/s13046-015-0166-1

Caspase-3 promotes genetic instability and carcinogenesis.

Apoptosis is typically considered an anti-oncogenic process since caspase activation can promote the elimination of genetically unstable or damaged cells. We report that a central effector of apoptosis, caspase-3, facilitates rather than suppresses chemical- and radiation-induced genetic instability and carcinogenesis. We found that a significant fraction of mammalian cells treated with ionizing radiation can survive despite caspase-3 activation. Moreover, this sublethal activation of caspase-3 promoted persistent DNA damage and oncogenic transformation. In addition, chemically induced skin carcinogenesis was significantly reduced in mice genetically deficient in caspase-3. Furthermore, attenuation of EndoG activity significantly reduced radiation-induced DNA damage and oncogenic transformation, identifying EndoG as a downstream effector of caspase-3 in this pathway. Our findings suggest that rather than acting as a broad inhibitor of carcinogenesis, caspase-3 activation may contribute to genome instability and play a pivotal role in tumor formation following damage.

Authors
Liu, X; He, Y; Li, F; Huang, Q; Kato, TA; Hall, RP; Li, C-Y
MLA Citation
Liu, X, He, Y, Li, F, Huang, Q, Kato, TA, Hall, RP, and Li, C-Y. "Caspase-3 promotes genetic instability and carcinogenesis." Molecular cell 58.2 (April 9, 2015): 284-296.
PMID
25866249
Source
epmc
Published In
Molecular Cell
Volume
58
Issue
2
Publish Date
2015
Start Page
284
End Page
296
DOI
10.1016/j.molcel.2015.03.003

Dying tumor cells stimulate proliferation of living tumor cells via caspase-dependent protein kinase Cδ activation in pancreatic ductal adenocarcinoma

© 2014 Federation of European Biochemical Societies.Pancreatic cancer is one of the most lethal human cancers, and radiotherapy is often implemented for locally advanced pancreatic ductal adenocarcinoma. Tumor cell repopulation is a major challenge in treating cancers after radiotherapy. In order to address the problem of tumor repopulation, our previous studies have demonstrated that dying cells stimulate the proliferation of living tumor cells after radiotherapy. In particular, dying cells undergoing apoptosis also activate survival or proliferation signals and release growth factors to surrounding living cells. In the present study, we used an invitro model to examine the possible mechanisms for dying cell stimulated tumor repopulation in pancreatic cancer. In this model, a small number of living, luciferase-labeled pancreatic cancer cells (reporter) were seeded onto a layer of a much larger number of irradiated, unlabeled pancreatic cancer cells and the growth of the living cells was measured over time as a gage of tumor repopulation. Our results indicate that irradiated, dying Panc1 feeder cells significantly stimulated the proliferation of living Panc1 reporter cells. Importantly, we identified that the percentage of apoptotic cells and the cleavage of caspases 3 and 7 and protein kinase Cδ (PKCδ) were increased in irradiated Panc1 cells. We presumed that caspases 3 and 7 and PKCδ as integral mediators in the process of dying pancreatic cancer cell stimulation of living tumor cell growth. In order to demonstrate the importance of caspases 3, 7 and PKCδ, we introduced dominant-negative mutants of caspase 3 (DN_C3), caspase 7 (DN_C7), or PKCδ (DN_PKCδ) into Panc1 cells using lentiviral vectors. The stably transduced Panc1 cells were irradiated and used as feeders and we found a significant decrease in the growth of living Panc1 reporter cells when compared with irradiated wild-type Panc1 cells as feeders. Moreover, the role of PKCδ in the growth stimulation of living tumor cells was further confirmed using a pan PKC inhibitor GF109203x and a specific PKCδ inhibitor, rottlerin. Additionally, we found significantly increased phosphorylation of Akt, p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase/stress-activated protein kinase (JNK1/2) in the irradiated Panc1 cells. Mechanistically, PKCδ cleavage was attenuated in both DN_C3 and DN_C7 transduced Panc1 cells, and both Akt and p38 MAPK phosphorylation were attenuated in DN_PKCδ transduced Panc1 cells following radiation. Thus, this report suggests a novel finding that cellular signaling caspase 3/7-PKCδ-Akt/p38 MAPK is crucial to the repopulation in Panc1 cells after radiotherapy.

Authors
Cheng, J; Tian, L; Ma, J; Gong, Y; Zhang, Z; Chen, Z; Xu, B; Xiong, H; Li, C; Huang, Q
MLA Citation
Cheng, J, Tian, L, Ma, J, Gong, Y, Zhang, Z, Chen, Z, Xu, B, Xiong, H, Li, C, and Huang, Q. "Dying tumor cells stimulate proliferation of living tumor cells via caspase-dependent protein kinase Cδ activation in pancreatic ductal adenocarcinoma." Molecular Oncology 9.1 (January 1, 2015): 105-114.
Source
scopus
Published In
Molecular Oncology
Volume
9
Issue
1
Publish Date
2015
Start Page
105
End Page
114
DOI
10.1016/j.molonc.2014.07.024

Caspase-3 Promotes Genetic Instability and Carcinogenesis

© 2015 Elsevier Inc.Apoptosis is typically considered an anti-oncogenic process since caspase activation can promote the elimination of genetically unstable or damaged cells. We report that a central effector of apoptosis, caspase-3, facilitates rather than suppresses chemical- and radiation-induced genetic instability and carcinogenesis. We found that a significant fraction of mammalian cells treated with ionizing radiation can survive despite caspase-3 activation. Moreover, this sublethal activation of caspase-3 promoted persistent DNA damage and oncogenic transformation. In addition, chemically induced skin carcinogenesis was significantly reduced in mice genetically deficient in caspase-3. Furthermore, attenuation ofEndoG activity significantly reduced radiation-induced DNA damage and oncogenic transformation, identifying EndoG as a downstream effector of caspase-3 in this pathway. Our findings suggest that rather than acting as a broad inhibitor of carcinogenesis, caspase-3 activation may contribute to genome instability and play a pivotal role in tumor formation following damage.

Authors
Liu, X; He, Y; Li, F; Huang, Q; Kato, TA; Hall, RP; Li, CY
MLA Citation
Liu, X, He, Y, Li, F, Huang, Q, Kato, TA, Hall, RP, and Li, CY. "Caspase-3 Promotes Genetic Instability and Carcinogenesis." Molecular Cell 58.2 (January 1, 2015): 284-296.
Source
scopus
Published In
Molecular Cell
Volume
58
Issue
2
Publish Date
2015
Start Page
284
End Page
296
DOI
10.1016/j.molcel.2015.03.003

Dying tumor cells stimulate proliferation of living tumor cells via caspase-dependent protein kinase Cδ activation in pancreatic ductal adenocarcinoma.

Pancreatic cancer is one of the most lethal human cancers, and radiotherapy is often implemented for locally advanced pancreatic ductal adenocarcinoma. Tumor cell repopulation is a major challenge in treating cancers after radiotherapy. In order to address the problem of tumor repopulation, our previous studies have demonstrated that dying cells stimulate the proliferation of living tumor cells after radiotherapy. In particular, dying cells undergoing apoptosis also activate survival or proliferation signals and release growth factors to surrounding living cells. In the present study, we used an in vitro model to examine the possible mechanisms for dying cell stimulated tumor repopulation in pancreatic cancer. In this model, a small number of living, luciferase-labeled pancreatic cancer cells (reporter) were seeded onto a layer of a much larger number of irradiated, unlabeled pancreatic cancer cells and the growth of the living cells was measured over time as a gage of tumor repopulation. Our results indicate that irradiated, dying Panc1 feeder cells significantly stimulated the proliferation of living Panc1 reporter cells. Importantly, we identified that the percentage of apoptotic cells and the cleavage of caspases 3 and 7 and protein kinase Cδ (PKCδ) were increased in irradiated Panc1 cells. We presumed that caspases 3 and 7 and PKCδ as integral mediators in the process of dying pancreatic cancer cell stimulation of living tumor cell growth. In order to demonstrate the importance of caspases 3, 7 and PKCδ, we introduced dominant-negative mutants of caspase 3 (DN_C3), caspase 7 (DN_C7), or PKCδ (DN_PKCδ) into Panc1 cells using lentiviral vectors. The stably transduced Panc1 cells were irradiated and used as feeders and we found a significant decrease in the growth of living Panc1 reporter cells when compared with irradiated wild-type Panc1 cells as feeders. Moreover, the role of PKCδ in the growth stimulation of living tumor cells was further confirmed using a pan PKC inhibitor GF109203x and a specific PKCδ inhibitor, rottlerin. Additionally, we found significantly increased phosphorylation of Akt, p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase/stress-activated protein kinase (JNK1/2) in the irradiated Panc1 cells. Mechanistically, PKCδ cleavage was attenuated in both DN_C3 and DN_C7 transduced Panc1 cells, and both Akt and p38 MAPK phosphorylation were attenuated in DN_PKCδ transduced Panc1 cells following radiation. Thus, this report suggests a novel finding that cellular signaling caspase 3/7-PKCδ-Akt/p38 MAPK is crucial to the repopulation in Panc1 cells after radiotherapy.

Authors
Cheng, J; Tian, L; Ma, J; Gong, Y; Zhang, Z; Chen, Z; Xu, B; Xiong, H; Li, C; Huang, Q
MLA Citation
Cheng, J, Tian, L, Ma, J, Gong, Y, Zhang, Z, Chen, Z, Xu, B, Xiong, H, Li, C, and Huang, Q. "Dying tumor cells stimulate proliferation of living tumor cells via caspase-dependent protein kinase Cδ activation in pancreatic ductal adenocarcinoma." Molecular oncology 9.1 (January 2015): 105-114.
PMID
25156550
Source
epmc
Published In
Molecular Oncology
Volume
9
Issue
1
Publish Date
2015
Start Page
105
End Page
114
DOI
10.1016/j.molonc.2014.07.024

Dissecting the roles of E1A and E1B in adenoviral replication and RCAd-enhanced RDAd transduction efficacy on tumor cells.

Oncolytic viruses have recently received widespread attention for their potential in innovative cancer therapy. Many telomerase promoter-regulated oncolytic adenoviral vectors retain E1A and E1B. However, the functions of E1A and E1B proteins in the oncolytic role of replication-competent adenovirus (RCAd) and RCAd enhanced transduction of replication defective adenoviruses (RDAd) have not been addressed well. In this study, we constructed viruses expressing E1A alone, E1A plus E1B-19 kDa, and E1A plus E1B-19 kDa/55 kDa. We then tested their roles in oncolysis and replication of RCAd as well as their roles in RCAd enhanced transfection rate and transgene expression of RDAd in various cancer cells in vitro and in xenografted human NCI-H460 tumors in nude mice. We demonstrated that RCAds expressing E1A alone and plus E1B-19 kDa exhibited an obvious ability in replication and oncolytic effects as well as enhanced RDAd replication and transgene expression, with the former showed more effective oncolysis, while the latter exhibited superior viral replication and transgene promotion activity. However, RCAd expressing both E1A and E1B-19 kDa/55 kDa was clearly worst in all these abilities. The effects of E1A and E1B observed through using RCAd were further validated by using plasmids expressing E1A alone, E1A plus E1B-19 kDa, and E1A plus E1B-19 kDa/55 kDa proteins. Our study provided evidence that E1A was essential for inducing replication and oncolytic effects of RCAd as well as RCAd enhanced RDAd transduction, and expression of E1B-19 kDa other than E1B-55 kDa could promote these effects. E1B-55 kDa is not necessary for the oncolytic effects of adenoviruses and somehow inhibits RCAd-mediated RDAd replication and transgene expression.

Authors
Wei, F; Wang, H; Chen, X; Li, C; Huang, Q
MLA Citation
Wei, F, Wang, H, Chen, X, Li, C, and Huang, Q. "Dissecting the roles of E1A and E1B in adenoviral replication and RCAd-enhanced RDAd transduction efficacy on tumor cells." Cancer biology & therapy 15.10 (October 2014): 1358-1366.
PMID
25019940
Source
epmc
Published In
Cancer Biology and Therapy
Volume
15
Issue
10
Publish Date
2014
Start Page
1358
End Page
1366
DOI
10.4161/cbt.29842

Enhancing the efficiency of direct reprogramming of human primary fibroblasts into dopaminergic neuron-like cells through p53 suppression.

Dopaminergic (DA) neuron-like cells obtained through direct reprogramming of primary human fibroblasts offer exciting opportunities for treatment of Parkinson's disease. A significant obstacle is the low efficiency of conversion during the reprogramming process. Here, we demonstrate that the suppression of p53 significantly enhances the efficiency of transcription factor-mediated conversion of human fibroblasts into functional dopaminergic neurons. In particular, blocking p53 activity using a dominant-negative p53 (p53-DN) in IMR90 cells increases the conversion efficiency by 5-20 fold. The induced DA neuron-like cells exhibit dopamine neuron-specific gene expression, significant dopamine uptake and production capacities, and enables symptomatic relief in a rat Parkinson's disease model. Taken together, our findings suggest that p53 is a critical barrier in direct reprogramming of fibroblast into dopaminergic neurons.

Authors
Liu, X; Huang, Q; Li, F; Li, C-Y
MLA Citation
Liu, X, Huang, Q, Li, F, and Li, C-Y. "Enhancing the efficiency of direct reprogramming of human primary fibroblasts into dopaminergic neuron-like cells through p53 suppression." Science China. Life sciences 57.9 (September 2014): 867-875.
PMID
25129808
Source
epmc
Published In
Science in China Series C: Life Sciences
Volume
57
Issue
9
Publish Date
2014
Start Page
867
End Page
875
DOI
10.1007/s11427-014-4730-2

Caspase 3 promotes surviving melanoma tumor cell growth after cytotoxic therapy.

Metastatic melanoma often relapses despite cytotoxic treatment, and hence the understanding of melanoma tumor repopulation is crucial for improving our current therapies. In this study, we aim to define the role of caspase 3 in melanoma tumor growth after cytotoxic therapy. We examined a paradigm-changing hypothesis that dying melanoma cells undergoing apoptosis during cytotoxic treatment activate paracrine signaling events that promote the growth of surviving tumor cells. We propose that caspase 3 has a key role in the initiation of the release of signals from dying cells to stimulate melanoma tumor growth. We created a model for tumor cell repopulation in which a small number of luciferase-labeled, untreated melanoma cells are seeded onto a layer of a larger number of unlabeled, lethally treated melanoma cells. We found that dying melanoma cells significantly stimulate the growth of living melanoma cells in vitro and in vivo. Furthermore, we observed that caspase 3 gene knockdown attenuated the growth-stimulating effect of irradiated, dying cells on living melanoma cell growth. Finally, we showed that caspase 3-mediated dying melanoma cell stimulation of living cell growth involves secreted prostaglandin E2 (PGE2). Our study therefore suggests a counterintuitive strategy to inhibit caspase 3 for therapeutic gain in melanoma treatment.

Authors
Donato, AL; Huang, Q; Liu, X; Li, F; Zimmerman, MA; Li, C-Y
MLA Citation
Donato, AL, Huang, Q, Liu, X, Li, F, Zimmerman, MA, and Li, C-Y. "Caspase 3 promotes surviving melanoma tumor cell growth after cytotoxic therapy." The Journal of investigative dermatology 134.6 (June 2014): 1686-1692.
PMID
24434746
Source
epmc
Published In
Journal of Investigative Dermatology
Volume
134
Issue
6
Publish Date
2014
Start Page
1686
End Page
1692
DOI
10.1038/jid.2014.18

Caspase 3 Promotes Surviving Melanoma Tumor Cell Growth after Cytotoxic Therapy

Authors
Donato, AL; Huang, Q; Liu, X; Li, F; Zimmerman, MA; Li, C-Y
MLA Citation
Donato, AL, Huang, Q, Liu, X, Li, F, Zimmerman, MA, and Li, C-Y. "Caspase 3 Promotes Surviving Melanoma Tumor Cell Growth after Cytotoxic Therapy." Journal of Investigative Dermatology 134.6 (June 2014): 1686-1692.
Source
crossref
Published In
Journal of Investigative Dermatology
Volume
134
Issue
6
Publish Date
2014
Start Page
1686
End Page
1692
DOI
10.1038/jid.2014.18

Mathematical modeling of the Phoenix Rising pathway.

Apoptosis is a tightly controlled process in mammalian cells. It is important for embryogenesis, tissue homoeostasis, and cancer treatment. Apoptosis not only induces cell death, but also leads to the release of signals that promote rapid proliferation of surrounding cells through the Phoenix Rising (PR) pathway. To quantitatively understand the kinetics of interactions of different molecules in this pathway, we developed a mathematical model to simulate the effects of various changes in the PR pathway on the secretion of prostaglandin E2 (PGE2), a key factor for promoting cell proliferation. These changes include activation of caspase 3 (C3), caspase 7 (C7), and nuclear factor κB (NFκB). In addition, we simulated the effects of cyclooxygenase-2 (COX2) inhibition and C3 knockout on the level of secreted PGE2. The model predictions on PGE2 in MEF and 4T1 cells at 48 hours after 10-Gray radiation were quantitatively consistent with the experimental data in the literature. Compared to C7, the model predicted that C3 activation was more critical for PGE2 production. The model also predicted that PGE2 production could be significantly reduced when COX2 expression was blocked via either NFκB inactivation or treatment of cells with exogenous COX2 inhibitors, which led to a decrease in the rate of conversion from arachidonic acid to prostaglandin H2 in the PR pathway. In conclusion, the mathematical model developed in this study yielded new insights into the process of tissue regrowth stimulated by signals from apoptotic cells. In future studies, the model can be used for experimental data analysis and assisting development of novel strategies/drugs for improving cancer treatment or normal tissue regeneration.

Authors
Liu, C; Li, C-Y; Yuan, F
MLA Citation
Liu, C, Li, C-Y, and Yuan, F. "Mathematical modeling of the Phoenix Rising pathway." PLoS computational biology 10.2 (February 6, 2014): e1003461-.
PMID
24516373
Source
epmc
Published In
PLoS computational biology
Volume
10
Issue
2
Publish Date
2014
Start Page
e1003461
DOI
10.1371/journal.pcbi.1003461

A novel EGFR isoform confers increased invasiveness to cancer cells.

As a validated therapeutic target in several human cancers, the EGF receptor (EGFR) provides a focus to gain deeper insights into cancer pathophysiology. In this study, we report the identification of a naturally occurring and widely expressed EGFR isoform termed EGFRvA, which substitutes a Ser/Thr-rich peptide for part of the carboxyl-terminal regulatory domain of the receptor. Intriguingly, EGFRvA expression relates more closely to histopathologic grade and poor prognosis in patients with glioma. Ectopic expression of EGFRvA in cancer cells conferred a higher invasive capacity than EGFR in vitro and in vivo. Mechanistically, EGFRvA stimulated expression of STAT3, which upregulated heparin-binding EGF (HB-EGF). Reciprocally, HB-EGF stimulated phosphorylation of EGFRvA at Y845 along with STAT3, generating a positive feedback loop that may reinforce invasive function. The significance of EGFRvA expression was reinforced by findings that it is attenuated by miR-542-5p, a microRNA that is a known tumor suppressor. Taken together, our findings define this newfound EGFR isoform as a key theranostic molecule.

Authors
Zhou, M; Wang, H; Zhou, K; Luo, X; Pan, X; Shi, B; Jiang, H; Zhang, J; Li, K; Wang, H-M; Gao, H; Lu, S; Yao, M; Mao, Y; Wang, H-Y; Yang, S; Gu, J; Li, C; Li, Z
MLA Citation
Zhou, M, Wang, H, Zhou, K, Luo, X, Pan, X, Shi, B, Jiang, H, Zhang, J, Li, K, Wang, H-M, Gao, H, Lu, S, Yao, M, Mao, Y, Wang, H-Y, Yang, S, Gu, J, Li, C, and Li, Z. "A novel EGFR isoform confers increased invasiveness to cancer cells." Cancer Res 73.23 (December 1, 2013): 7056-7067.
PMID
24240702
Source
pubmed
Published In
Cancer Research
Volume
73
Issue
23
Publish Date
2013
Start Page
7056
End Page
7067
DOI
10.1158/0008-5472.CAN-13-0194

Preface

Authors
Zhou, D; Li, CY
MLA Citation
Zhou, D, and Li, CY. "Preface." Translational Cancer Research 2.5 (October 1, 2013): 370-371.
Source
scopus
Published In
Translational cancer research
Volume
2
Issue
5
Publish Date
2013
Start Page
370
End Page
371
DOI
10.3978/j.issn.2218-676X.2013.10.06

Cell death-stimulated cell proliferation: a tissue regeneration mechanism usurped by tumors during radiotherapy.

The death of all the cancer cells in a tumor is the ultimate goal of cancer therapy. Therefore, much of the current effort in cancer research is focused on activating cellular machinery that facilitates cell death such as factors involved in causing apoptosis. However, recently, a number of studies point to some counterintuitive roles for apoptotic caspases in radiation therapy as well as in tissue regeneration. It appears that a major function of apoptotic caspases is to facilitate tissue regeneration and tumor cell repopulation during cancer therapy. Because tumor cell repopulation has been shown to be important for local tumor relapse, understanding the molecular mechanisms behind tumor repopulation would be important to enhance cancer radiotherapy. In this review, we discuss our current knowledge of these potentially paradigm-changing phenomena and mechanisms in various organisms and their implications on the development of novel cancer therapeutics and strategies.

Authors
Zimmerman, MA; Huang, Q; Li, F; Liu, X; Li, C-Y
MLA Citation
Zimmerman, MA, Huang, Q, Li, F, Liu, X, and Li, C-Y. "Cell death-stimulated cell proliferation: a tissue regeneration mechanism usurped by tumors during radiotherapy." Semin Radiat Oncol 23.4 (October 2013): 288-295. (Review)
PMID
24012343
Source
pubmed
Published In
Seminars in Radiation Oncology
Volume
23
Issue
4
Publish Date
2013
Start Page
288
End Page
295
DOI
10.1016/j.semradonc.2013.05.003

Apoptosis and caspase 3 stimulate melanoma tumor repopulation during vemurafenib and PD0325901 therapy

Authors
Donato, AL; Huang, Q; Li, F; Liu, X; Li, C
MLA Citation
Donato, AL, Huang, Q, Li, F, Liu, X, and Li, C. "Apoptosis and caspase 3 stimulate melanoma tumor repopulation during vemurafenib and PD0325901 therapy." May 2013.
Source
wos-lite
Published In
Journal of Investigative Dermatology
Volume
133
Publish Date
2013
Start Page
S222
End Page
S222

Relationship of oral glycine with radiation-induced HIF1-alpha and tumor growth delay in a prostate cancer xenograft

Authors
Kessler, ER; Su, L-J; Yang, X; Altunbas, C; Flaig, TW; Li, C-Y; Kavanagh, BD
MLA Citation
Kessler, ER, Su, L-J, Yang, X, Altunbas, C, Flaig, TW, Li, C-Y, and Kavanagh, BD. "Relationship of oral glycine with radiation-induced HIF1-alpha and tumor growth delay in a prostate cancer xenograft." February 20, 2013.
Source
wos-lite
Published In
Journal of Clinical Oncology
Volume
31
Issue
6
Publish Date
2013

Pharmacokinetics of combined gene therapy expressing constitutive human GM-CSF and hyperthermia-regulated human IL-12.

BACKGROUND: An adenovirus that expresses both interleukin (IL)-12 and granulocyte-macrophage colony-stimulating-factor (GM-CSF) has been proven to be very effective in treating several tumors, but causes serious normal tissue toxicities. METHODS: In this study, a novel adenoviral vector was constructed by placing the human GM-CSF gene under the control of the CMV-IE promoter and human IL-12 gene under the control of heat shock protein 70B gene promoter. Both hGM-CSF and hIL-12 expressions in virus-infected tumor cells were analyzed in vitro and in vivo when underlying single or multiple rounds of hyperthermia. RESULTS: We observed constitutive high expression of human GM-CSF and heat-induced expression of human IL-12 after a single round of hyperthermia post viral infection. The heat-induced hIL-12 expression exhibited a pulse-like pattern with a peak at 24 hrs followed by a decline 48 hrs post heat stress. Repeated heat treatment was more effective in inducing hIL-12 expression than a one-time heat treatment. Interestedly, we also observed that constitutive expression of hGM-CSF could be stimulated by heat stress in tested tumor cells. CONCLUSION: Our study provided a novel strategy for combined gene therapy that allows constitutive expression of a non-toxic gene such as GM-CSF and heat-induced expression of a toxic gene such as IL-12. In addition, our study also showed that hyperthermia can be used to trigger gene expression in temporal and special manner.

Authors
Wei, F; Wang, H; Zhang, J; Chen, X; Li, C; Huang, Q
MLA Citation
Wei, F, Wang, H, Zhang, J, Chen, X, Li, C, and Huang, Q. "Pharmacokinetics of combined gene therapy expressing constitutive human GM-CSF and hyperthermia-regulated human IL-12. (Published online)" J Exp Clin Cancer Res 32 (January 26, 2013): 5-.
PMID
23352035
Source
pubmed
Published In
Journal of Experimental & Clinical Cancer Research
Volume
32
Publish Date
2013
Start Page
5
DOI
10.1186/1756-9966-32-5

Identification of novel predictive markers for the prognosis of pancreatic ductal adenocarcinoma

Pancreatic cancer is a disease with poor prognosis and high mortality. To identify novel molecular markers that could predict the prognosis of pancreatic ductal adenocarcinoma, a total of 114 pancreatic ductal adenocarcinomas and 99 peritumoral tissues were collected. Protein levels of cleaved caspase-3, cyclin D1, epidermal growth factor receptor and Her-2 (human epidermal growth factor receptor 2) were measured by immunohistochemistry. Molecular abnormalities of cyclin D1/q11, Her-2/q17, and epidermal growth factor receptor/p7 were detected using fluorescence in situ hybridization. Results demonstrated that the protein levels of cleaved caspase-3, epidermal growth factor receptor, Her-2, and cyclin D1 were significantly higher in pancreatic ductal adenocarcinoma than that in peritumoral tissues (P =.000). Significantly more amplifications of epidermal growth factor receptor, Her-2, and cyclin D1 were observed in pancreatic ductal adenocarcinoma patients than in peritumoral tissues. In addition, 51.8% of pancreatic ductal adenocarcinoma tumors showed polysomy 7, 50% showed polysomy 11, and 40.4% showed polysomy 17. However, no polysomy was observed in peritumoral tissues. Her-2 amplification and polysomy 17 significantly correlated with poor prognosis of pancreatic ductal adenocarcinoma (P =.008 and P =.005, respectively). Interestingly, only cleaved caspase-3 protein level significantly correlated with poor survival in pancreatic ductal adenocarcinoma patients (P =.000). We also observed significant correlations of cleaved caspase-3 level with epidermal growth factor receptor, Her-2, and cyclin D1 protein levels and the molecular abnormalities of Her-2 and cyclin D1. Conclusively, cleaved caspase-3 level is an ideal biomarker to predict prognosis in pancreatic ductal adenocarcinoma patients and might be a better target for pancreatic ductal adenocarcinoma treatment than epidermal growth factor receptor/Her-2 and cyclin D1. © 2013 Elsevier Inc. All rights reserved.

Authors
Luo, Y; Qiu, Z; Tian, L; Zhu, G; Feng, Y; Yi, M; Chen, X; Wang, L; Li, C; Huang, Q
MLA Citation
Luo, Y, Qiu, Z, Tian, L, Zhu, G, Feng, Y, Yi, M, Chen, X, Wang, L, Li, C, and Huang, Q. "Identification of novel predictive markers for the prognosis of pancreatic ductal adenocarcinoma." Human Pathology 44.1 (2013): 69-76.
PMID
22939953
Source
scival
Published In
Human Pathology
Volume
44
Issue
1
Publish Date
2013
Start Page
69
End Page
76
DOI
10.1016/j.humpath.2012.04.014

Molecular markers of therapeutic resistance in breast cancer

Resistance to chemotherapy and endocrine therapy is a serious obstacle in the treatment of breast cancer. Highly specific biomarkers for predicting therapeutic resistance have not yet been identified. In this study, the amounts of aldehyde dehydrogenase 1, cleaved caspase 3, cyclooxygenase 2, phosphorylated Akt, Ki-67, and H2AX proteins were measured by immunohistochemical staining in 113 breast cancer tissues, and their predictive ability for therapeutic resistance was investigated. The patients were receiving chemotherapy (n = 30), endocrine therapy (n = 22), or combined chemotherapy and endocrine therapy (n = 61). Expression of aldehyde dehydrogenase 1, cleaved caspase 3, and cyclooxygenase 2 correlated significantly with a higher relapse rate (P < .05 or P < .01) and shorter survival (P < .01 or P < .001) in triple-negative patients receiving chemotherapy. In addition, cyclooxygenase 2 expression was an independent predictor of a poor prognosis (P < .05). On the other hand, aldehyde dehydrogenase 1 expression correlated significantly with shorter survival in patients receiving combined therapy (P < .01) but showed no association with relapse. No correlation was observed between Ki-67, phosphorylated Akt, and H2AX expression and survival or relapse in any group of patients. These data suggest that aldehyde dehydrogenase 1, cleaved caspase 3, and cyclooxygenase 2 are useful markers for therapeutic resistance in breast cancer. © 2012 Elsevier Inc. All rights reserved.

Authors
Zhou, L; Luo, Y; Li, K; Tian, L; Wang, M; Li, C; Huang, Q
MLA Citation
Zhou, L, Luo, Y, Li, K, Tian, L, Wang, M, Li, C, and Huang, Q. "Molecular markers of therapeutic resistance in breast cancer." Human Pathology (2013).
PMID
23434145
Source
scival
Published In
Human Pathology
Publish Date
2013
DOI
10.1016/j.humpath.2012.10.027

Diphtheria toxin-epidermal growth factor fusion protein DAB 389EGF for the treatment of bladder cancer

Purpose: The novel fusion protein, DAB389EGF, is composed of both the catalytic and the translocation domains of diphtheria toxin that are fused to the human EGF, providing a targeting and a toxicity component. We tested DAB389EGF for antitumor activity in both in vitro and in vivo urinary bladder cancer models. Experimental Design: Human bladder cancer lines were treated with DAB389EGF and assessed for growth inhibition and clonogenic suppression. Using 6- to 8-week-old female athymic nude mice implanted orthotopically with HTB9 cells, DAB389EGF was administered intravesically twice weekly for 2 weeks. The response of the luciferase-expressing HTB9 cells was monitored via bioluminescence as the primary endpoint. Results: Treatment response with DAB389EGF was specific and robust, with an IC50 ranging from 0.5 to 15 ng/mL in eight tested bladder cancer cell lines, but greater than 50 ng/mL in the EGF receptor (EGFR)-negative H520 control cell line. Simulating short-duration intravesical therapy used clinically, a 2-hour treatment exposure of DAB 389EGF (10 ng/mL) produced clonogenic suppression in three selected bladder cancer cell lines. In vivo, luciferase activity was suppressed in five of six mice treated with DAB389EGF [70 μL (1 ng/μL) per mouse], as compared with only one of six mice treated with a control diphtheria toxin (DT) fusion protein. Histologic assessment of tumor clearance correlated with the bioluminescent changes observed with DAB389EGF treatment. Immunocompetent mice treated with intravesical DAB389EGF did not show any nonspecific systemic toxicity. Conclusions: The intravesical delivery of targeted toxin fusion proteins is a novel treatment approach for non-muscle-invasive urinary bladder cancer. With appropriate targeting, the treatments are effective and well-tolerated in vivo. ©2012 AACR.

Authors
Yang, X; Kessler, E; Su, L-J; Thorburn, A; Frankel, AE; Li, Y; Rosa, FGL; Shen, J; Li, C-Y; Varella-Garcia, M; Glodé, LM; Flaig, TW
MLA Citation
Yang, X, Kessler, E, Su, L-J, Thorburn, A, Frankel, AE, Li, Y, Rosa, FGL, Shen, J, Li, C-Y, Varella-Garcia, M, Glodé, LM, and Flaig, TW. "Diphtheria toxin-epidermal growth factor fusion protein DAB 389EGF for the treatment of bladder cancer." Clinical Cancer Research 19.1 (2013): 148-157.
PMID
23172881
Source
scival
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
19
Issue
1
Publish Date
2013
Start Page
148
End Page
157
DOI
10.1158/1078-0432.CCR-12-1258

Molecular markers of therapeutic resistance in breast cancer

Resistance to chemotherapy and endocrine therapy is a serious obstacle in the treatment of breast cancer. Highly specific biomarkers for predicting therapeutic resistance have not yet been identified. In this study, the amounts of aldehyde dehydrogenase 1, cleaved caspase 3, cyclooxygenase 2, phosphorylated Akt, Ki-67, and H2AX proteins were measured by immunohistochemical staining in 113 breast cancer tissues, and their predictive ability for therapeutic resistance was investigated. The patients were receiving chemotherapy (n = 30), endocrine therapy (n = 22), or combined chemotherapy and endocrine therapy (n = 61). Expression of aldehyde dehydrogenase 1, cleaved caspase 3, and cyclooxygenase 2 correlated significantly with a higher relapse rate (P <.05 or P <.01) and shorter survival (P <.01 or P <.001) in triple-negative patients receiving chemotherapy. In addition, cyclooxygenase 2 expression was an independent predictor of a poor prognosis (P <.05). On the other hand, aldehyde dehydrogenase 1 expression correlated significantly with shorter survival in patients receiving combined therapy (P <.01) but showed no association with relapse. No correlation was observed between Ki-67, phosphorylated Akt, and H2AX expression and survival or relapse in any group of patients. These data suggest that aldehyde dehydrogenase 1, cleaved caspase 3, and cyclooxygenase 2 are useful markers for therapeutic resistance in breast cancer. © 2013 Elsevier Inc.

Authors
Zhou, L; Luo, Y; Li, K; Tian, L; Wang, M; Li, C; Huang, Q
MLA Citation
Zhou, L, Luo, Y, Li, K, Tian, L, Wang, M, Li, C, and Huang, Q. "Molecular markers of therapeutic resistance in breast cancer." Human Pathology 44.7 (2013): 1421-1428.
Source
scival
Published In
Human Pathology
Volume
44
Issue
7
Publish Date
2013
Start Page
1421
End Page
1428
DOI
10.1016/j.humpath.2012.10.027

Sonic Hedgehog Signaling Pathway Supports Cancer Cell Growth during Cancer Radiotherapy

Tumor growth after radiotherapy is a commonly recognized cause of therapeutic failure. In this way, we examined tumor cell growth after radiotherapy by establishing a cancer cell growth model in vitro. We accomplished this model by seeding non-irradiated firefly luciferase2 and green fluorescent protein fusion gene (Fluc) labeled living cancer reporter cells onto a feeder layer of irradiated cancer cells. The living tumor cell growth was monitored by bioluminescence imaging. The living reporter cells grew faster when seeded onto lethally irradiated feeder cells than when seeded onto non-irradiated feeder cells or when seeded in the absence of feeder cells. We found that the expression levels of the Shh and Gli1 proteins, both of which are critical proteins in Sonic hedgehog (SHH) signaling, were increased after irradiation and that this expression was positively correlated with reporter cell growth. Moreover, the dying cell stimulation of living tumor cell growth was enhanced by the addition of SHH signaling agonists and inhibited by SHH signaling antagonists. SHH agonists also enhanced reporter cell growth in the absence of irradiated feeder cells, suggesting this mechanism plays a role in feeder cell growth stimulation. Given these results, we conclude that SHH signaling activation plays an important role during tumor repopulation after radiotherapy. © 2013 Huang et al.

Authors
Ma, J; Tian, L; Cheng, J; Chen, Z; Xu, B; Wang, L; Li, C; Huang, Q
MLA Citation
Ma, J, Tian, L, Cheng, J, Chen, Z, Xu, B, Wang, L, Li, C, and Huang, Q. "Sonic Hedgehog Signaling Pathway Supports Cancer Cell Growth during Cancer Radiotherapy." PLoS ONE 8.6 (2013).
PMID
23762282
Source
scival
Published In
PloS one
Volume
8
Issue
6
Publish Date
2013
DOI
10.1371/journal.pone.0065032

Novel prognostic markers for patients with triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by poor prognosis. Currently, no reliable markers have been identified as having a predictive role for the prognosis of TNBC patients. In this study, 119 breast cancer samples, including 31 TNBC and 89 non-TNBC subtypes, were collected. The protein levels of cleaved caspase-3 (CC3), aldehyde dehydrogenase 1 (ALDH1), cyclooxygenase-2, Ki-67, H2A histone family member X, and phosphorylated protein kinase B protein were measured by immunohistochemical staining. The percentage of positive CC3 (P = .017), ALDH1 (P = .015), Ki-67 (P = .001), and H2A histone family member X (P = .016) staining was significantly higher in TNBC than in non-TNBC cases. Positive CC3 and ALDH1 staining significantly correlated with poor prognosis of breast cancer, the TNBC subtype and non-TNBC subtype. Positive cyclooxygenase-2 expression significantly correlated with the survival of patients with TNBC. Multivariate analysis demonstrated that CC3 and ALDH1 are independent prognostic factors for BC and non-TNBC. ALDH1 is a prognostic marker for TNBC patients. © 2013 Elsevier Inc. All rights reserved.

Authors
Zhou, L; Li, K; Luo, Y; Tian, L; Wang, M; Li, C; Huang, Q
MLA Citation
Zhou, L, Li, K, Luo, Y, Tian, L, Wang, M, Li, C, and Huang, Q. "Novel prognostic markers for patients with triple-negative breast cancer." Human Pathology (2013).
PMID
23845466
Source
scival
Published In
Human Pathology
Publish Date
2013
DOI
10.1016/j.humpath.2013.03.021

Novel prognostic markers for patients with triple-negative breast cancer

Summary Triple-negative breast cancer (TNBC) is a subtype of breast cancer characterized by poor prognosis. Currently, no reliable markers have been identified as having a predictive role for the prognosis of TNBC patients. In this study, 119 breast cancer samples, including 31 TNBC and 89 non-TNBC subtypes, were collected. The protein levels of cleaved caspase-3 (CC3), aldehyde dehydrogenase 1 (ALDH1), cyclooxygenase-2, Ki-67, H2A histone family member X, and phosphorylated protein kinase B protein were measured by immunohistochemical staining. The percentage of positive CC3 (P =.017), ALDH1 (P =.015), Ki-67 (P =.001), and H2A histone family member X (P =.016) staining was significantly higher in TNBC than in non-TNBC cases. Positive CC3 and ALDH1 staining significantly correlated with poor prognosis of breast cancer, the TNBC subtype and non-TNBC subtype. Positive cyclooxygenase-2 expression significantly correlated with the survival of patients with TNBC. Multivariate analysis demonstrated that CC3 and ALDH1 are independent prognostic factors for BC and non-TNBC. ALDH1 is a prognostic marker for TNBC patients. © 2013 Elsevier Inc.

Authors
Zhou, L; Li, K; Luo, Y; Tian, L; Wang, M; Li, C; Huang, Q
MLA Citation
Zhou, L, Li, K, Luo, Y, Tian, L, Wang, M, Li, C, and Huang, Q. "Novel prognostic markers for patients with triple-negative breast cancer." Human Pathology 44.10 (2013): 2180-2187.
Source
scival
Published In
Human Pathology
Volume
44
Issue
10
Publish Date
2013
Start Page
2180
End Page
2187
DOI
10.1016/j.humpath.2013.03.021

Inhibitors of DNA repair for cancer therapy, ready for prime time?

© 2011 - 2016 Translational Cancer Research. All rights reserved.Genomic DNA is the central storage place for cellular information in DNA-based life forms. However, its integrity is under constant threat from errors in the replication process and damage from environmental insults. To neutralize these threats, our cells have developed elaborate mechanisms to repair DNA damage.

Authors
Li, CY
MLA Citation
Li, CY. "Inhibitors of DNA repair for cancer therapy, ready for prime time?." Translational Cancer Research 1.1 (June 1, 2012): 4-5.
Source
scopus
Published In
Translational cancer research
Volume
1
Issue
1
Publish Date
2012
Start Page
4
End Page
5
DOI
10.3978/j.issn.2218-676X.2012.05.08

Oncolytic virus-mediated tumor radiosensitization in mice through DNA-PKcs-specific shRNA.

One of the key issues in cancer radiotherapy research is to sensitize tumor cells to the cell killing effects of ionizing radiation while leaving normal tissues intact. One potential approach to achieve this is through tumor-specific targeting of DNA repair genes. In this study, we engineered a replication-deficient adenovirus encoding a mini shRNA gene targeted to the DNA-PKcs gene, which is involved in double strand break DNA repair, and evaluated its anti-tumor efficacy in combination with radiotherapy. Our shRNA-encoding adenovirus showed significant efficacy in down-regulating the levels of the DNA-PKcs protein that was accompanied by increased radiation sensitivity in the human HCT116 colon cancer cells. However, when delivered intratumorally to xenograft human tumors, minimal anti-tumor effects of the virus were seen either alone or in combination with radiation therapy, suggesting an inefficiency of the non-replicative adenovirus in delivering shRNA genes to the tumor mass. When a conditionally replicative adenovirus targeted to telomerase-positive tumor cells was used in conjunction with the DNA-PKcs-targeted shRNA-encoding non-replicative adenovirus, the efficiency of tumor-specific anti-DNA-PKcs shRNA gene expression was enhanced significantly. Most importantly, this enhanced shRNA expression led to significant anti-tumor efficacy of concurrently delivered radiation therapy. Our results suggest our shRNA-based DNA-PKcs- targeting approach in combination with tumor-targeting replicative adenovirus is a promising method to sensitize solid tumors to radiation therapy.

Authors
Kon, T; Zhang, X; Huang, Q; Yang, Z; Liu, S; Yan, B; Li, F; Wang, H; Li, C-Y
MLA Citation
Kon, T, Zhang, X, Huang, Q, Yang, Z, Liu, S, Yan, B, Li, F, Wang, H, and Li, C-Y. "Oncolytic virus-mediated tumor radiosensitization in mice through DNA-PKcs-specific shRNA." Translational cancer research 1.2 (June 2012): 4-14.
PMID
22924158
Source
epmc
Published In
Translational cancer research
Volume
1
Issue
2
Publish Date
2012
Start Page
4
End Page
14
DOI
10.3978/j.issn.2218-676x.2012.05.02

A facilitative role for caspase 3 & caspase 7 in wound healing and tissue regeneration

Authors
Li, F; Huang, Q; Chen, J; Roop, DR; Li, C
MLA Citation
Li, F, Huang, Q, Chen, J, Roop, DR, and Li, C. "A facilitative role for caspase 3 & caspase 7 in wound healing and tissue regeneration." May 2012.
Source
wos-lite
Published In
Journal of Investigative Dermatology
Volume
132
Publish Date
2012
Start Page
S137
End Page
S137

Direct reprogramming of human fibroblasts int dopaminergic neurons

Authors
Liu, X; Li, F; Stublefield, EA; Blanchard, B; Richards, T; Larson, GA; Huang, Q; Benke, TA; Sladek, JR; Li, C
MLA Citation
Liu, X, Li, F, Stublefield, EA, Blanchard, B, Richards, T, Larson, GA, Huang, Q, Benke, TA, Sladek, JR, and Li, C. "Direct reprogramming of human fibroblasts int dopaminergic neurons." May 2012.
Source
wos-lite
Published In
Journal of Investigative Dermatology
Volume
132
Publish Date
2012
Start Page
S138
End Page
S138

A counter-intuitive role for apoptotic caspase 3 in treatment of melanoma and other cancers

Authors
Huang, Q; Li, F; Liu, X; Li, W; Liu, F; O'Sullivan, B; Wang, X; Li, C
MLA Citation
Huang, Q, Li, F, Liu, X, Li, W, Liu, F, O'Sullivan, B, Wang, X, and Li, C. "A counter-intuitive role for apoptotic caspase 3 in treatment of melanoma and other cancers." May 2012.
Source
wos-lite
Published In
Journal of Investigative Dermatology
Volume
132
Publish Date
2012
Start Page
S124
End Page
S124

Imaging molecular pathways: reporter genes.

Molecular imaging is a rapidly advancing field that allows cancer biologists to look deeper into the complex inner workings of tumor cells, or whole tumors, in a non-invasive manner. In this review, we will summarize some recent advances that enable investigators to study various important biological processes in tumors in vivo. We will discuss novel imaging approaches that allow investigators to visualize and quantify molecular pathways, such as receptor tyrosine kinase activation, hypoxia signal transduction, apoptosis, and DNA double-strand breaks. Select examples of these applications will be discussed. Because of the limited scope of this review, we will only focus on natural reporters, such as bioluminescence and fluorescent proteins.

Authors
Brogan, J; Li, F; Li, W; He, Z; Huang, Q; Li, C-Y
MLA Citation
Brogan, J, Li, F, Li, W, He, Z, Huang, Q, and Li, C-Y. "Imaging molecular pathways: reporter genes." Radiat Res 177.4 (April 2012): 508-513. (Review)
PMID
22348248
Source
pubmed
Published In
Radiation Research
Volume
177
Issue
4
Publish Date
2012
Start Page
508
End Page
513

Heat induces gene amplification in cancer cells

Background: Hyperthermia plays an important role in cancer therapy. However, as with radiation, it can cause DNA damage and therefore genetic instability. We studied whether hyperthermia can induce gene amplification in cancer cells and explored potential underlying molecular mechanisms. Materials and methods: (1) Hyperthermia: HCT116 colon cancer cells received water-submerged heating treatment at 42 or 44. °C for 30. min; (2) gene amplification assay using N-(phosphoacetyl)-l-aspartate (PALA) selection of cabamyl-P-synthetase, aspartate transcarbarmylase, dihydro-orotase (cad) gene amplified cells; (3) southern blotting for confirmation of increased cad gene copies in PALA-resistant cells; (4) γH2AX immunostaining to detect γH2AX foci as an indication for DNA double strand breaks. Results: (1) Heat exposure at 42 or 44. °C for 30. min induces gene amplification. The frequency of cad gene amplification increased by 2.8 and 6.5 folds respectively; (2) heat exposure at both 42 and 44. °C for 30. min induces DNA double strand breaks in HCT116 cells as shown by γH2AX immunostaining. Conclusion: This study shows that heat exposure can induce gene amplification in cancer cells, likely through the generation of DNA double strand breaks, which are believed to be required for the initiation of gene amplification. This process may be promoted by heat when cellular proteins that are responsible for checkpoints, DNA replication, DNA repair and telomere functions are denatured. To our knowledge, this is the first study to provide direct evidence of hyperthermia induced gene amplification. © 2012 Elsevier Inc.

Authors
Yan, B; Ouyang, R; Huang, C; Liu, F; Neill, D; Li, C; Dewhirst, M
MLA Citation
Yan, B, Ouyang, R, Huang, C, Liu, F, Neill, D, Li, C, and Dewhirst, M. "Heat induces gene amplification in cancer cells." Biochemical and Biophysical Research Communications 427.3 (2012): 473-477.
PMID
22975353
Source
scival
Published In
Biochemical and Biophysical Research Communications
Volume
427
Issue
3
Publish Date
2012
Start Page
473
End Page
477
DOI
10.1016/j.bbrc.2012.09.011

Enhancement of rAAV2-mediated transgene expression in retina cells in vitro and in vivo by coadministration of low-Dose chemotherapeutic drugs

Purpose. Recombinant adeno-associated viral vector serotype 2 (rAAV2) has been used with success to deliver retina-targeted gene therapeutics in retinal degeneration. However, one of the major limitations of this approach is the vector's low transduction efficiency. This study is designed to increase AAV2 transduction efficiency in vitro and in vivo. Methods. Green fluorescence protein (GFP) or luciferase reporter gene-carried rAAV2 vectors were applied to cultured human RPE cells (ARPE-19) or animal eyes with or without chemotherapeutic agents. GFP transduction efficiency was evaluated by image, flow cytometry analysis, and Western blot. The ciliary neurotrophic factor (rAAV2-CNTF)-carried AAV2 vector was coinjected to subretinal space with or without chemotherapeutic agent. The therapeutic efficacy was evaluated by counting numbers of remaining photoreceptors in retina sections of treated or untreated eyes. Results. Coadministration of 0.1 lg/mL doxorubicin (DXR), 0.14 lg/mL cytarabine (Ara-C), 1 lg/mL etoposide (VP-16), or 20 lg/mL cisplatin (DDP) significantly increased rAAV2-mediated GFP and/or luciferase expression in cultured hRPE cells without any detectable toxicity. Pretreatment with DXR for 24 h prior to infection was most effective in enhancing rAAV2 transgene expression in hRPE cells. In addition, subretinal coinjection of rAAV2-CMV-ciliary neurotrophic factor (rAAV2-CNTF) and DXR into the eyes of rats with inherited retinal degeneration resulted in an approximately 2-fold increase in photoreceptor layer thickness and cellular density of the outer nuclear layer (ONL) compared to rAAV2-CNTF alone, reflecting a pronounced protection effect mediated by the enhanced expression of CNTF. Conclusions. The method described here to improve rAAV2-based gene delivery is simple and feasible without any detectable toxicity. This strategy might be therapeutically exploited in the gene therapy of degenerative retinal diseases. (Invest Ophthalmol Vis Sci. 2012;53:2675-2684) ©2012 The Association for Research in Vision and Ophthalmology, Inc.

Authors
Zhang, S; Wu, J; Wu, X; Xu, P; Tian, Y; Yi, M; Liu, X; Dong, X; Wolf, F; Li, C; Huang, Q
MLA Citation
Zhang, S, Wu, J, Wu, X, Xu, P, Tian, Y, Yi, M, Liu, X, Dong, X, Wolf, F, Li, C, and Huang, Q. "Enhancement of rAAV2-mediated transgene expression in retina cells in vitro and in vivo by coadministration of low-Dose chemotherapeutic drugs." Investigative Ophthalmology and Visual Science 53.6 (2012): 2675-2684.
PMID
22427581
Source
scival
Published In
Investigative Ophthalmology and Visual Science
Volume
53
Issue
6
Publish Date
2012
Start Page
2675
End Page
2684
DOI
10.1167/iovs.11-8856

A novel immunocompetent murine tumor model for the evaluation of RCAd-enhanced RDAd transduction efficacy

Low gene transfer rate in tumors, high dose-induced acute inflammatory response, and lack of an immunocompetent preclinical animal model to accurately reflect the therapeutic efficacy are prominent reasons for the lack of clinical success of adenoviral (Ad) vectors. In this study, we tested whether human replication-competent adenovirus (RCAd) can replicate in T739 mouse bladder transitional tumor cells (BTT) and lung adenocarcinoma cells (LA795), and whether RCAd can enhance the transduction rate and transgene expression of human replication defective adenoviruses (RDAd) in these tumor cells in vitro and in vivo. We demonstrated that human RCAd exhibited good infectability and cytopathologic effects in mouse BTT and LA795 cells, which was comparable to that in A549 and NCIH460 human tumor cells. In contrast, no infectability and cytopathologic effects were observed in other three mouse tumor cells such as 4T1, B16, and Lewis cells. The combined use of RCAd with RDAd significantly enhanced RDAd transduction efficiency in BTT and LA795 tumor cells in vitro and in vivo. When BTT and LA795 cells were co-infected with RDAd Ad-EGFP and RCAd, a large amount of E1a expression and 2-3 orders of increases in Ad-EGFP genomic DNA were observed. In contrast, the expression of the late gene Hexon is very low, which may explain ineffective packaging of viral particles. In conclusion, our study provided a novel immunocompetent animal model which is useful for evaluating RCAd infectability, cytopathy, and replication. The combined use of RCAd and RDAd provided a new solution for cancer gene therapy. © 2012 International Society of Oncology and BioMarkers (ISOBM).

Authors
Wang, H; Wei, F; Zhang, J; Wang, F; Li, H; Chen, X; Xie, K; Wang, Y; Li, C; Huang, Q
MLA Citation
Wang, H, Wei, F, Zhang, J, Wang, F, Li, H, Chen, X, Xie, K, Wang, Y, Li, C, and Huang, Q. "A novel immunocompetent murine tumor model for the evaluation of RCAd-enhanced RDAd transduction efficacy." Tumor Biology (2012): 1-9.
PMID
22627833
Source
scival
Published In
Tumor Biology
Publish Date
2012
Start Page
1
End Page
9
DOI
10.1007/s13277-012-0374-7

Direct reprogramming of human fibroblasts into dopaminergic neuron-like cells

Transplantation of exogenous dopaminergic neuron (DA neurons) is a promising approach for treating Parkinson's disease (PD). However, a major stumbling block has been the lack of a reliable source of donor DA neurons. Here we show that a combination of five transcriptional factors Mash1, Ngn2, Sox2, Nurr1, and Pitx3 can directly and effectively reprogram human fibroblasts into DA neuron-like cells. The reprogrammed cells stained positive for various markers for DA neurons. They also showed characteristic DA uptake and production properties. Moreover, they exhibited DA neuron-specific electrophysiological profiles. Finally, they provided symptomatic relief in a rat PD model. Therefore, our directly reprogrammed DA neuron-like cells are a promising source of cell-replacement therapy for PD. © 2012 IBCB, SIBS, CAS. All rights reserved.

Authors
Liu, X; Li, F; Stubblefield, EA; Blanchard, B; Richards, TL; Larson, GA; He, Y; Huang, Q; Tan, A-C; Zhang, D; Benke, TA; Sladek, JR; Zahniser, NR; Li, C-Y
MLA Citation
Liu, X, Li, F, Stubblefield, EA, Blanchard, B, Richards, TL, Larson, GA, He, Y, Huang, Q, Tan, A-C, Zhang, D, Benke, TA, Sladek, JR, Zahniser, NR, and Li, C-Y. "Direct reprogramming of human fibroblasts into dopaminergic neuron-like cells." Cell Research 22.2 (2012): 321-332.
PMID
22105488
Source
scival
Published In
Cell Research
Volume
22
Issue
2
Publish Date
2012
Start Page
321
End Page
332
DOI
10.1038/cr.2011.181

A novel immunocompetent murine tumor model for the evaluation of RCAd-enhanced RDAd transduction efficacy.

Low gene transfer rate in tumors, high dose-induced acute inflammatory response, and lack of an immunocompetent preclinical animal model to accurately reflect the therapeutic efficacy are prominent reasons for the lack of clinical success of adenoviral (Ad) vectors. In this study, we tested whether human replication-competent adenovirus (RCAd) can replicate in T739 mouse bladder transitional tumor cells (BTT) and lung adenocarcinoma cells (LA795), and whether RCAd can enhance the transduction rate and transgene expression of human replication defective adenoviruses (RDAd) in these tumor cells in vitro and in vivo. We demonstrated that human RCAd exhibited good infectability and cytopathologic effects in mouse BTT and LA795 cells, which was comparable to that in A549 and NCIH460 human tumor cells. In contrast, no infectability and cytopathologic effects were observed in other three mouse tumor cells such as 4T1, B16, and Lewis cells. The combined use of RCAd with RDAd significantly enhanced RDAd transduction efficiency in BTT and LA795 tumor cells in vitro and in vivo. When BTT and LA795 cells were co-infected with RDAd Ad-EGFP and RCAd, a large amount of E1a expression and 2-3 orders of increases in Ad-EGFP genomic DNA were observed. In contrast, the expression of the late gene Hexon is very low, which may explain ineffective packaging of viral particles. In conclusion, our study provided a novel immunocompetent animal model which is useful for evaluating RCAd infectability, cytopathy, and replication. The combined use of RCAd and RDAd provided a new solution for cancer gene therapy.

Authors
Wang, H; Wei, F; Zhang, J; Wang, F; Li, H; Chen, X; Xie, K; Wang, Y; Li, C; Huang, Q
MLA Citation
Wang, H, Wei, F, Zhang, J, Wang, F, Li, H, Chen, X, Xie, K, Wang, Y, Li, C, and Huang, Q. "A novel immunocompetent murine tumor model for the evaluation of RCAd-enhanced RDAd transduction efficacy." Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine 33.4 (2012): 1245-1253.
Source
scival
Published In
Tumor Biology
Volume
33
Issue
4
Publish Date
2012
Start Page
1245
End Page
1253
DOI
10.1007/s13277-012-0374-7

Non-invasive, quantitative monitoring of hyperthermia-induced EGFR activation in xenograft tumours

Purpose: To examine the molecular mechanism of cellular EGFR activation during hyperthermia treatment. Materials and methods: EGR activities in tumour cells were quantified through the use of a recently developed split-luciferase-based EGFR reporter system which allowed us to monitor EGFR activation in vitro as well as in vivo in a non-invasive manner. Results: We found that hyperthermia treatment of MDA-MB231 breast cancer cells resulted in a strong induction of EGFR activity in tissue culture as well as in xenograft tumours. Furthermore, we found that this induction is mediated by the heat shock protein Hsp90. Administration of the specific Hsp90 inhibitor geldanamycin as well as RNAi directed against HSP90 effectively inhibited EGFR activation, suggesting an essential role for Hsp90 in hyperthermia-induced EGFR activation. In addition, cells treated with geldanamycin were sensitised to heat treatment, suggesting that adding Hsp90 inhibitors to hyperthermia regimens might have a beneficial effect for cancer treatment. Conclusions: Our bioluminescent imaging reporter provided a powerful tool to examine hyperthermia-induced EGFR activation in vitro as well as in vivo. Hsp90 was found to be a key factor mediating heat-induced EGFR activation in tumour cells. © 2011 Informa UK Ltd All rights reserved.

Authors
Wolf, F; Li, W; Li, F; Li, C-Y
MLA Citation
Wolf, F, Li, W, Li, F, and Li, C-Y. "Non-invasive, quantitative monitoring of hyperthermia-induced EGFR activation in xenograft tumours." International Journal of Hyperthermia 27.5 (2011): 427-434.
PMID
21756040
Source
scival
Published In
International Journal of Hyperthermia (Informa)
Volume
27
Issue
5
Publish Date
2011
Start Page
427
End Page
434
DOI
10.3109/02656736.2011.566593

Caspase 3-mediated stimulation of tumor cell repopulation during cancer radiotherapy

In cancer treatment, apoptosis is a well-recognized cell death mechanism through which cytotoxic agents kill tumor cells. Here we report that dying tumor cells use the apoptotic process to generate potent growth-stimulating signals to stimulate the repopulation of tumors undergoing radiotherapy. Furthermore, activated caspase 3, a key executioner in apoptosis, is involved in the growth stimulation. One downstream effector that caspase 3 regulates is prostaglandin E 2 (PGE 2), which can potently stimulate growth of surviving tumor cells. Deficiency of caspase 3 either in tumor cells or in tumor stroma caused substantial tumor sensitivity to radiotherapy in xenograft or mouse tumors. In human subjects with cancer, higher amounts of activated caspase 3 in tumor tissues are correlated with markedly increased rate of recurrence and death. We propose the existence of a cell death-induced tumor repopulation pathway in which caspase 3 has a major role. © 2011 Nature America, Inc. All rights reserved.

Authors
Huang, Q; Li, F; Liu, X; Li, W; Shi, W; Liu, F-F; O'Sullivan, B; He, Z; Peng, Y; Tan, A-C; Zhou, L; Shen, J; Han, G; Wang, X-J; Thorburn, J; Thorburn, A; Jimeno, A; Raben, D; Bedford, JS; Li, C-Y
MLA Citation
Huang, Q, Li, F, Liu, X, Li, W, Shi, W, Liu, F-F, O'Sullivan, B, He, Z, Peng, Y, Tan, A-C, Zhou, L, Shen, J, Han, G, Wang, X-J, Thorburn, J, Thorburn, A, Jimeno, A, Raben, D, Bedford, JS, and Li, C-Y. "Caspase 3-mediated stimulation of tumor cell repopulation during cancer radiotherapy." Nature Medicine 17.7 (2011): 860-866.
PMID
21725296
Source
scival
Published In
Nature Medicine
Volume
17
Issue
7
Publish Date
2011
Start Page
860
End Page
866
DOI
10.1038/nm.2385

Quantitative, noninvasive imaging of radiation-induced DNA double-strand breaks in vivo

DNA double-strand breaks (DSB) are a major form of DNA damage and a key mechanism through which radiotherapy and some chemotherapeutic agents kill cancer cells. Despite its importance, measuring DNA DSBs is still a tedious task that is normally carried out by gel electrophoresis or immunofluorescence staining. Here, we report a novel approach to image and quantify DSBs in live mammalian cells through bifragment luciferase reconstitution. N- and C-terminal fragments of firefly luciferase genes were fused with H2AX and MDC1 genes, respectively. Our strategy was based on the established fact that at the sites of DSBs, H2AX protein is phosphoryated and physically associates with the MDC1 protein, thus bringing together N- and C-luciferase fragments and reconstituting luciferase activity. Our strategy allowed serial, noninvasive quantification of DSBs in cells irradiated with X-rays and 56Fe ions. Furthermore, it allowed for the evaluation of DSBs noninvasively in vivo in irradiated tumors over 2 weeks. Surprisingly, we detected a second wave of DSB induction in irradiated tumor cells days after radiation exposure in addition to the initial rapid induction of DSBs. We conclude that our new split-luciferase-based method for imaging γ-H2AX-MDC1 interaction is a powerful new tool to study DSB repair kinetics in vivo with considerable advantage for experiments requiring observations over an extended period of time. ©2011 AACR.

Authors
Li, W; Li, F; Huang, Q; Shen, J; Wolf, F; He, Y; Liu, X; Hu, YA; Bedford, JS; Li, C-Y
MLA Citation
Li, W, Li, F, Huang, Q, Shen, J, Wolf, F, He, Y, Liu, X, Hu, YA, Bedford, JS, and Li, C-Y. "Quantitative, noninvasive imaging of radiation-induced DNA double-strand breaks in vivo." Cancer Research 71.12 (2011): 4130-4137.
PMID
21527553
Source
scival
Published In
Cancer Research
Volume
71
Issue
12
Publish Date
2011
Start Page
4130
End Page
4137
DOI
10.1158/0008-5472.CAN-10-2540

Novel luciferase-based reporter system to monitor activation of ErbB2/Her2/neu pathway noninvasively during radiotherapy

Purpose: To develop a split-luciferase-based reporter system that allows for noninvasive monitoring of activation of the Her2/neu pathway in vivo in a quantitative and sensitive manner. Methods and Materials: Fusion proteins of the ErbB2/Her2/neu receptor to the N-terminal fragment of luciferase and of its downstream binding partner Shc to the C-terminal fragment of luciferase have been engineered owing to the rationale that on activation and binding of the Her2 receptor molecule to Shc, luciferase function will be reconstituted. Thus, the resulting bioluminescence signals can serve as a surrogate measure of receptor activation. Results: We have shown that our reporter systems functions well in vitro in breast cancer cells and in vivo in xenograft tumors. In particular, the activities of Her2/neu in xenograft tumors could be monitored serially for an extended period after radiotherapy. Conclusions: We believe that the novel ErbB2/Her2/neu reporter we have presented is a powerful tool to study the biology of the Her2-neu pathway in vitro and in vivo. It should also facilitate the development and rapid evaluation of new Her2/neu-targeted therapeutic agents. © 2011 Elsevier Inc. Printed in the USA. All rights reserved.

Authors
Wolf, F; Li, W; Li, F; Li, C-Y
MLA Citation
Wolf, F, Li, W, Li, F, and Li, C-Y. "Novel luciferase-based reporter system to monitor activation of ErbB2/Her2/neu pathway noninvasively during radiotherapy." International Journal of Radiation Oncology Biology Physics 79.1 (2011): 233-238.
PMID
20934271
Source
scival
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
79
Issue
1
Publish Date
2011
Start Page
233
End Page
238
DOI
10.1016/j.ijrobp.2010.08.001

A novel conditionally replicating "armed" adenovirus selectively targeting gastrointestinal tumors with aberrant wnt signaling

Using conditionally replicating adenoviral vectors (CRAds) is a promising strategy in the treatment of solid tumors. The prospective of this study was to design a novel CRAd for the treatment of gastrointestinal cancer and show its efficacy in vitro, as well as in vivo. To determine if aberrant wnt signaling in tumor cells can be used to selectively drive viral replication, we analyzed six colorectal and hepatocellular cell lines, as well as 13 colorectal tumors and 17 gastric tumors, for β-catenin mutation status or aberrant wnt signaling, both of which were found frequently. Based on these findings, a novel CRAd (Ad5F11.wnt-E1A-hIL24) containing an E1A expression cassette driven by an artificial wnt promoter and delivering an apoptosis-inducing gene, interleukin-24 (IL24), was engineered. To enhance infection efficiency, the virus was pseudotyped by replacing adenovirus serotype 5 (Ad5) with Ad11 fiber. Ad5F11.wnt-E1A-hIL24 virus exhibited high selectivity toward cells with aberrant wnt signaling both in vitro and in mouse xenograft tumors. Transduction efficiency was significantly improved compared with that of nonpseudotyped control viruses. The proliferation of tumor cell lines, as well as tumor growth, in mouse xenografts could be profoundly inhibited by viral infection with Ad5F11.wnt-E1A-hIL24. The therapeutic effect was associated with increased apoptosis through caspase-3 activation. In addition, Ad5F11b vector exhibited a more favorable biodistribution, blood clearance, and transgene expression compared with conventional Ad5 vector after systemic or intratumoral injection in human gastrointestinal cancer xenografts. We think that our approach is a promising strategy in the treatment of gastrointestinal cancer, warranting further clinical investigation. © 2011 Mary Ann Liebert, Inc.

Authors
Liu, X; Qian, Q; Xu, P; Wolf, F; Zhang, J; Zhang, D; Li, C; Huang, Q
MLA Citation
Liu, X, Qian, Q, Xu, P, Wolf, F, Zhang, J, Zhang, D, Li, C, and Huang, Q. "A novel conditionally replicating "armed" adenovirus selectively targeting gastrointestinal tumors with aberrant wnt signaling." Human Gene Therapy 22.4 (2011): 427-437.
PMID
20925459
Source
scival
Published In
Human Gene Therapy
Volume
22
Issue
4
Publish Date
2011
Start Page
427
End Page
437
DOI
10.1089/hum.2010.128

Apoptotic caspases regulate induction of iPSCs from human fibroblasts

The molecular mechanisms involved in the derivation of induced pluripotent stem cells (iPSCs) from differentiated cells are poorly understood. Here we report that caspases 3 and 8, two proteases associated with apoptotic cell death, play critical roles in induction of iPSCs from human fibroblasts. Activation of caspases 3 and 8 occurs soon after transduction of iPSC-inducing transcription factors. Oct-4, a key iPSC transcription factor, is responsible for the activation. Inhibition of caspase 3 or 8 in human fibroblast cells partially or completely (respectively) prevents the induction of iPSCs. Furthermore, retinoblastoma susceptibility (Rb) protein appears to be one of the factors that act downstream of the caspases. We propose that caspases are key facilitators of nuclear reprogramming in iPSC induction. © 2010 Elsevier Inc.

Authors
Li, F; He, Z; Shen, J; Huang, Q; Li, W; Liu, X; He, Y; Wolf, F; Li, C-Y
MLA Citation
Li, F, He, Z, Shen, J, Huang, Q, Li, W, Liu, X, He, Y, Wolf, F, and Li, C-Y. "Apoptotic caspases regulate induction of iPSCs from human fibroblasts." Cell Stem Cell 7.4 (2010): 508-520.
PMID
20887956
Source
scival
Published In
Cell Stem Cell
Volume
7
Issue
4
Publish Date
2010
Start Page
508
End Page
520
DOI
10.1016/j.stem.2010.09.003

Need radioprotection? A MEPE/OF45 mimetic may do the job

Authors
Li, C-Y
MLA Citation
Li, C-Y. "Need radioprotection? A MEPE/OF45 mimetic may do the job." Cell Cycle 9.12 (2010): 2271--.
PMID
20581437
Source
scival
Published In
Cell Cycle
Volume
9
Issue
12
Publish Date
2010
Start Page
2271-

Science signaling podcast: 23 February 2010

Authors
Li, C-Y; Hook, AMV
MLA Citation
Li, C-Y, and Hook, AMV. "Science signaling podcast: 23 February 2010." Science Signaling 3.110 (2010): pc5-.
Source
scival
Published In
Science Signaling
Volume
3
Issue
110
Publish Date
2010
Start Page
pc5
DOI
10.1126/scisignal.3110pc5

Apoptotic cells activate the "phoenix rising" pathway to promote wound healing and tissue regeneration

The ability to regenerate damaged tissues is a common characteristic of multicellular organisms. We report a role for apoptotic cell death in promoting wound healing and tissue regeneration in mice. Apoptotic cells released growth signals that stimulated the proliferation of progenitor or stem cells. Key players in this process were caspases 3 and 7, proteases activated during the execution phase of apoptosis that contribute to cell death. Mice lacking either of these caspases were deficient in skin wound healing and in liver regeneration. Prostaglandin E2, a promoter of stem or progenitor cell proliferation and tissue regeneration, acted downstream of the caspases. We propose to call the pathway by which executioner caspases in apoptotic cells promote wound healing and tissue regeneration in multicellular organisms the "phoenix rising" pathway. Copyright 2008 the American Association for the Advancement of Science; all rights reserved.

Authors
Li, F; Huang, Q; Chen, J; Peng, Y; Roop, DR; Bedford, JS; Li, C-Y
MLA Citation
Li, F, Huang, Q, Chen, J, Peng, Y, Roop, DR, Bedford, JS, and Li, C-Y. "Apoptotic cells activate the "phoenix rising" pathway to promote wound healing and tissue regeneration." Science Signaling 3.110 (2010): ra13-.
PMID
20179271
Source
scival
Published In
Science Signaling
Volume
3
Issue
110
Publish Date
2010
Start Page
ra13
DOI
10.1126/scisignal.2000634

Enhanced pancreatic cancer gene therapy by combination of adenoviral vector expressing c-erb-B2 (Her-2=neu)-targeted immunotoxin with a replication-competent adenovirus or etoposide

Pancreatic cancer is the fourth leading cause of cancer-related death in the United States, and even under optimal therapy these patients face a poor prognosis. Here we report a novel gene therapy-based strategy to battle this disease. We show that the majority of pancreatic tumors overexpress c-erb-B2, which therefore might serve as a target for novel therapies. On the basis of these findings, we developed an adenoviral vector [Ad-e23(scFv)- PE40] encoding a c-erb-B2 (Her-2=neu)-targeted immunotoxin. To improve viral gene delivery we coinfected the therapeutic adenovirus with a replication-competent adenovirus (RCAd) at low doses that enhanced the transduction efficiency of the former virus. In addition, we show that target gene expression can be enhanced by adding etoposide (VP16) at nontherapeutic doses. To investigate the therapeutic efficacy of our approach we established a mouse model for advanced pancreatic cancer disease by intraperitoneal injection of pancreatic cancer cell lines, resulting in multifocal peritoneal xenograft tumors. Administration of Ad-e23(scFv)-PE40 in combination with RCAd and VP16 significantly inhibited tumor growth in mice, with no apparent systemic toxicity. In this study we show that c-erb-B2 might be an effective molecular target in the treatment of pancreatic tumors and that coadministration of a therapeutic c-erb-B2-targeted, non-replication-competent adenovirus with an RCAd and VP16 could be a powerful approach to effectively deliver therapeutic genes to tumors. As demonstrated, this strategy can be employed to effectively treat pancreatic cancer in particular, but may be modified to treat other types of cancer as well.

Authors
Liu, X; Li, J; Tian, Y; Xu, P; Chen, X; Xie, K; Qiu, Z; Wang, Y; Zhang, D; Wolf, F; Li, C; Huang, Q
MLA Citation
Liu, X, Li, J, Tian, Y, Xu, P, Chen, X, Xie, K, Qiu, Z, Wang, Y, Zhang, D, Wolf, F, Li, C, and Huang, Q. "Enhanced pancreatic cancer gene therapy by combination of adenoviral vector expressing c-erb-B2 (Her-2=neu)-targeted immunotoxin with a replication-competent adenovirus or etoposide." Human Gene Therapy 21.2 (2010): 157-170.
PMID
19751100
Source
scival
Published In
Human Gene Therapy
Volume
21
Issue
2
Publish Date
2010
Start Page
157
End Page
170
DOI
10.1089/hum.2009.083

Increased skin carcinogenesis in caspase-activated DNase knockout mice.

Caspase-activated DNase (CAD), also called DNA fragmentation factor (DFF), is the enzyme responsible for DNA fragmentation during apoptosis, a hallmark of programmed cell death. CAD/DFF has been shown to suppress radiation-induced carcinogenesis by preventing genomic instability in cells. In this study, we have investigated the role of CAD in chemical carcinogenesis using CAD-null mice and two-stage model of skin carcinogenesis. After topical treatment of mouse skin with dimethylbenz[a]anthracene (DMBA) as an initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as a promoting agent, there was a 4-fold increase in the number of papillomas per mouse and 50.8% increase in the incidence of papilloma formation in the CAD knockout mice compared with wild-type littermates. The papillomas in CAD-null mice grew faster and reached larger sizes. These data indicate that loss of CAD function enhances tumorigenesis induced by a chemical carcinogen in the DMBA/TPA two-stage model of skin carcinogenesis in mice.

Authors
Yan, B; Wang, H; Xie, D; Wakamatsu, N; Anscher, MS; Dewhirst, MW; Mitchel, REJ; Chen, BJ; Li, C-Y
MLA Citation
Yan, B, Wang, H, Xie, D, Wakamatsu, N, Anscher, MS, Dewhirst, MW, Mitchel, REJ, Chen, BJ, and Li, C-Y. "Increased skin carcinogenesis in caspase-activated DNase knockout mice." Carcinogenesis 30.10 (October 2009): 1776-1780.
PMID
19541853
Source
pubmed
Published In
Carcinogenesis
Volume
30
Issue
10
Publish Date
2009
Start Page
1776
End Page
1780
DOI
10.1093/carcin/bgp146

Hyperthermia-induced HIF-1 activation and tumor reoxygenation

Authors
Moon, EJ; Li, C-Y; Batinic-Haberle, I; Dewhirst, M
MLA Citation
Moon, EJ, Li, C-Y, Batinic-Haberle, I, and Dewhirst, M. "Hyperthermia-induced HIF-1 activation and tumor reoxygenation." CANCER RESEARCH 69 (May 1, 2009).
Source
wos-lite
Published In
Cancer Research
Volume
69
Publish Date
2009

Construction and characterization of oncolytic adenovirus controlled under heat shock protein70 gene promoter

As an innovative class of promising cancer therapeutic, oncolytic adenovirus has been commonly used recently due to its ability to infect and lyse cancer cells specifically, while ideally leaving normal cells unharmed. A potential advantage of oncolytic adenoviral vectors over conventional antitumor agents is that viral replication in the tumor will amplify the input virus dose, leading to spread of the virus throughout the tumor. To observe the inhibiting effect of oncolytic adenovirus on the lung cancer cell growth in combination with hyperthermia and to determine whether it can improve the expression levels of therapeutic gene delivered by replication-deficient adenovirus, an oncolytic adenovirus named Ad-HSP70p-ElA was constructed by employing the human HSP70 gene promoter to drive the expression of adenovirus E1A gene. The experimental results show that in vitro, Ad-HSP70p-E1A can replicate in lung carcinoma A549 cell line and destroy those cancer cells to some extent. While combined with hyperthermia, the number of replicative virions released from lung carcinoma increased about 2-10 times and the oncolytic effect on lung carcinoma A549 cell line increased 5 times at least. In addition, when combined with oncolytic adenovirus Ad-HSP70p-E1A, replication-deficient adenoviruses such as AdGFP, Ad-CMV-hGMCSF and Ad-CMV-mIL12 at the moi of 10 are expected to lead to the expression level of therapeutic gene at higher levels. The green fluorescence protein increased 76.64 times, while cytokines GMCSF and IL12 increased 5 times and 7 times respectively.

Authors
Wei, F; Wang, H-P; Chen, X-F; Li, C-Y; Huang, Q
MLA Citation
Wei, F, Wang, H-P, Chen, X-F, Li, C-Y, and Huang, Q. "Construction and characterization of oncolytic adenovirus controlled under heat shock protein70 gene promoter." Progress in Biochemistry and Biophysics 36.12 (2009): 1536-1543.
Source
scival
Published In
Sheng wu hua xue yu sheng wu wu li jin zhan
Volume
36
Issue
12
Publish Date
2009
Start Page
1536
End Page
1543
DOI
10.3724/SP.J.1206.2009.00308

Novel strategies to augment genetically delivered immunotoxin molecular therapy for cancer therapy

Immunotoxin therapy is a promising molecular cancer treatment strategy. Its main advantage is seletive cytotoxicity towards tumor cells and minimal toxicity in normal tissues. However, a short half-life and rapid clearance severely hampers its clinical application. We report here a novel genetic approach in which a recombinant adenovirus vector was used to deliver an immunotoxin gene e23(scFv)-PE40 targeted to the oncogene c-erbB-2 (also known as Her2/neu). This vector, when combined with a low dose of a conditionally replicative adenovirus vector (CRAd), has enhanced tumor-killing ability either alone or in combination with the chemotherapeutic agent etoposide. Our data show that low-dose CRAd facilitated the replication of replication-deficient Ad-e23(scFv)-PE40 up to 6-20 times and the transcription of e23(scFv)-PE40 gene up to 12 times. Moreover, etoposide increased the e23(scFv)-PE40 transcription up to 8.5 times. Furthermore, we show that systemic application of Ad-e23(scFv)-PE40 and enhanced expression of the immunotoxin gene was well tolerated as determined by serum biochemical markers and histological examination of most vital organs. Taken together, our data support a novel genetic immunotoxin delivery approach that may yield enhanced efficacy against a variety of Her2/neu-expressing tumors. © 2009 Nature Publishing Group All rights reserved.

Authors
Liu, X; Wu, J; Zhang, S; Li, C; Huang, Q
MLA Citation
Liu, X, Wu, J, Zhang, S, Li, C, and Huang, Q. "Novel strategies to augment genetically delivered immunotoxin molecular therapy for cancer therapy." Cancer Gene Therapy 16.11 (2009): 861-872.
PMID
19461676
Source
scival
Published In
Cancer Gene Therapy
Volume
16
Issue
11
Publish Date
2009
Start Page
861
End Page
872
DOI
10.1038/cgt.2009.30

Noninvasive visualization of retinoblastoma growth and metastasis via bioluminescence imaging

Purpose. To establish human retinoblastoma (RB) animal models that allows sensitive, noninvasive and continuous monitoring of tumor growth and metastasis in vivo.Methods. The human RB tumor cell lines HXO-Rb44 and Y79 were engineered to express a fusion reporter gene allowing for bioluminescence and fluorescence imaging. Intraocular and met-astatic tumors were induced in immunodeficient nude mice by injection of bioluminescent RB cells into eye compartments and into the left ventricle or tail vein. The growth kinetics of intraocular and metastatic tumors was quantitatively and continuously monitored via bioluminescence imaging (BLI).Results. Intraocular injection of HXO-Rb44-GFP-luc cells resulted in 100%, 80%, and 80% successful RB tumor development in the anterior chamber, vitreal cavity and subretinal space, respectively. The subretinal injection of Y79-GFP-luc cells resulted in 100% tumor development. BLI signal intensity correlated with the number of tumor cells injected as well as the weight of the tumor-bearing eyes. After bilateral subretinal injection of HXO-Rb44-GFP-luc cells, one of six RB tumor mice developed brain metastasis. Intracardiac injection of HXO-Rb44-GFP-luc cells resulted in metastatic disease in 9 of 15 nude mice, whereas tail vein injection resulted in metastasis in 1 of 16. Metastases were developed in multiple organs, including lymph nodes, bone, and brain, resembling the metastatic profile in patients with RB.Conclusions. BLI allowed sensitive, noninvasive, and quantitative localization and monitoring of intraocular and metastatic RB tumor growth in vivo and thus may be a useful tool to study RB biology as well as anti-RB therapies. © Association for Research in Vision and Ophthalmology.

Authors
Ji, X; Cheng, L; Wei, F; Li, H; Wang, M; Tian, Y; Chen, X; Wang, Y; Wolf, F; Li, C; Huang, Q
MLA Citation
Ji, X, Cheng, L, Wei, F, Li, H, Wang, M, Tian, Y, Chen, X, Wang, Y, Wolf, F, Li, C, and Huang, Q. "Noninvasive visualization of retinoblastoma growth and metastasis via bioluminescence imaging." Investigative Ophthalmology and Visual Science 50.12 (2009): 5544-5551.
PMID
19608529
Source
scival
Published In
Investigative Ophthalmology and Visual Science
Volume
50
Issue
12
Publish Date
2009
Start Page
5544
End Page
5551
DOI
10.1167/iovs.08-3258

Oncolytic adenovirus delivering herpes simplex virus thymidine kinase suicide gene reduces the growth of human retinoblastoma in an in vivo mouse model

Oncolytic conditionally replicating adenoviruses (CRAd) can exclusively replicate in and lyse tumor cells and are therefore promising tools in cancer therapy. In this study, we combined the oncolytic potential of a CRAd with its ability to deliver a suicide gene (herpes simplex virus thymidine kinase suicide gene, HSVtk) in order to further enhance tumor cell killing in a human retinoblastoma (RB) mouse model. We could demonstrate that CRAd driven by the human telomerase reverse transcriptase (hTERT) promoter and armed with the HSV thymidine kinase suicide gene/ganciclovir (HSVtk/GCV) could very effectively reduce growth of human RB in an orthotopic nude mouse model. These findings suggest that hTERT promoter-driven CRAd in combination with HSVtk/GCV gene therapy could be a promising new approach for the treatment of RB. In addition, we found that hTERT promoter-driven CRAd replication occurred exclusively in human RB cells but not in primary human retinal pigment epithelial cells (hRPE), indicating that application of hTERT promoter-driven CRAd for the treatment of RB would be safe. © 2009 Elsevier Ltd. All rights reserved.

Authors
Ji, X; Zhang, J; Cheng, L; Wei, F; Li, H; Liu, X; Chen, X; Li, C; Wang, Y; Huang, Q
MLA Citation
Ji, X, Zhang, J, Cheng, L, Wei, F, Li, H, Liu, X, Chen, X, Li, C, Wang, Y, and Huang, Q. "Oncolytic adenovirus delivering herpes simplex virus thymidine kinase suicide gene reduces the growth of human retinoblastoma in an in vivo mouse model." Experimental Eye Research 89.2 (2009): 193-199.
PMID
19328781
Source
scival
Published In
Experimental Eye Research
Volume
89
Issue
2
Publish Date
2009
Start Page
193
End Page
199
DOI
10.1016/j.exer.2009.03.007

The effect of cobalt chloride on adenovirus gene expression

Objective: To investigate the effect of cobalt chloride (CoCl2) on transgene expression and viral particle titers in tumor cells infected by conditionally replicating adenovirus expression vector with hypoxia response elements (HRE)-regulated E1AE1B expression (Ad-5HRE-E1AE1B-RFP) and non-HRE regulated replication-deficient adenovirus expression vector (Ad-EGFP, Ad-Luc) in vitro and in vivo. Methods: Ad-5HRE-E1AE1B-RFP had five duplicated HRE and mini CMV acted as a promoter to drive E1AE1B expression and constitutive expression of RFP as reporter. The hypoxia model was optimized by exposing tumor cells to different concentrations of CoCl2. The hypoxia-inducible factor 1 alpha (HIF-1α) protein expression was determined by Western blotting. Under the optimized hypoxia model, the positive expression of exogenous gene and virus replication of Ad-5HRE-E1AE1B-RFP or Ad-EGFP-infected tumor cells were examined by conversed microscopic observation, FACS analysis and plaques formation test. Furthermore, transgene expression induced by combined application of hypoxia-inducible replicative adenovirus and replication deficient adenovirus (Ad-Luc) was also evaluated by examining the lucifererse activity in xenografted tumor models in nude mice by micro PET. Results: Western blotting results showed that CoCl2 at 0.4 and 0.08 μg/mL could stabilize and acumulate HIF-1α protein in gastric cancer SGC7901 cells, which could better mimic hypoxia condition. The microscopic observation and FACS analysis showed that CoCl2 at 0.4 μg/mL could remarkably increase the transduction efficacy of Ad-5HRE-E1AE1B-RFP, which was verified by significant increase in the percentage of positive expression of exogenous gene RFP and fluorescence intensity. But plaques formation test showed that Ad-5HRE-E1AE1B-RFP had no replication. CoCl2 0.4 μg/mL augmented the tranduction efficacy and expression levels of non-HRE regulated replication deficient adenovirus Ad-EGFP and Ad-Luc. Combined intratumoral injection of Ad-5HRE-E1AE1B-RFP and Ad-Luc significantly increased the expression of Ad-Luc in nude mice. Conclusion: CoCl2 markedly enhances transgene expression of recombinant adenovirus. However, the underlying mechanism is not only related to the CoCl2-induced hypoxia, but also probably related to regulation of gene transcription.

Authors
Liu, X-J; Ji, X-D; Tian, Y-H; Chen, X-F; Xie, K-C; Wu, J-H; Zhang, S-H; Xu, P; Li, C-Y; Huang, Q
MLA Citation
Liu, X-J, Ji, X-D, Tian, Y-H, Chen, X-F, Xie, K-C, Wu, J-H, Zhang, S-H, Xu, P, Li, C-Y, and Huang, Q. "The effect of cobalt chloride on adenovirus gene expression." Tumor 29.7 (2009): 603-610.
Source
scival
Published In
Tumor
Volume
29
Issue
7
Publish Date
2009
Start Page
603
End Page
610
DOI
10.3781/j.issn.1000-7431.2009.07.001

Molecular analysis of genetic instability caused by chronic inflammation.

Genetic instability is a hallmark of human cancers. It is the driving force for tumor development as it facilitates the accumulation of mutations in genes that regulate cell death and proliferation and therefore promotes malignant transformation. Chronic inflammation is a common underlying condition for human tumor development, accounting for approximately 20% of human cancers. TNFalpha is an important inflammation cytokine and is crucial to the development of inflammation-associated cancers. We have shown that TNFalpha can cause DNA damages through reactive oxygen species (ROS). TNFalpha treatment in cultured cells resulted in increased gene mutations, gene amplification, micronuclei formation and chromosomal instability. Antioxidants significantly reduced TNFalpha-induced genetic damage. In addition, TNFalpha treatment alone led to increased malignant transformation of mouse embryo fibroblasts, which could be partially suppressed by antioxidants. Therefore, genetic instability plays an important role in inflammation-associated cancers.

Authors
Yan, B; Peng, Y; Li, C-Y
MLA Citation
Yan, B, Peng, Y, and Li, C-Y. "Molecular analysis of genetic instability caused by chronic inflammation." Methods in molecular biology (Clifton, N.J.) 512 (2009): 15-28.
PMID
19347270
Source
scival
Published In
Methods in molecular biology (Clifton, N.J.)
Volume
512
Publish Date
2009
Start Page
15
End Page
28
DOI
10.1007/978-1-60327-530-9_2

In vivo bioluminescence imaging monitoring of hypoxia-inducible factor 1alpha, a promoter that protects cells, in response to chemotherapy.

OBJECTIVE: Bioluminescence imaging is a powerful technique that has shown that hypoxia-inducible factor 1 (HIF-1), a transcription factor that protects tumor cells from hypoxia, is up-regulated in tumors after radiation therapy. We tested the hypothesis that bioluminescence imaging would successfully and noninvasively depict an increase in HIF-1 in the novel therapeutic environment of chemotherapy and that, as in radiation therapy, the underlying mechanism involves inducible nitric oxide synthase originating in macrophages. Active HIF-1 consists of alpha and beta subunits that bind to promoter sequences in many genes, including those that protect endothelial cells, promote angiogenesis, and alter metastasis and tumor cell metabolism. MATERIALS AND METHODS: We grew 4T1 murine breast carcinoma cells with an HIF-1alpha luciferase reporter construct to 7 mm in the right rear flanks of 18 Balb-C mice. The mice were evenly randomized to receive one of the following single intraperitoneal doses: maximum tolerated dose cyclophosphamide (231.5 mg/kg), maximum tolerated dose paclitaxel (10 mg/kg), or control saline solution. Immunohistochemical analysis of tumor sections from the cyclophosphamide and control groups was performed 10 days after treatment to assess the intensity and distribution of HIF-1alpha expression, hypoxia, macrophage infiltration, and expression of macrophage-derived inducible nitric oxide synthase in tumor tissues treated with maximum tolerated dose cyclophosphamide compared with control tumors. RESULTS: Cyclophosphamide, but not paclitaxel, significantly inhibited tumor growth and caused a significant increase in HIF-1alpha protein levels, which peaked at a 10-fold increase from baseline on day 10 after administration. In contrast, paclitaxel did not have an antitumor effect in this model and did not cause a significant increase in HIF-1alpha. Immunohistochemical analysis showed increased and more evenly dispersed levels of HIF-1alpha protein, macrophage infiltration, and expression of inducible nitric oxide synthase originating in macrophages after cyclophosphamide treatment. CONCLUSION: We successfully monitored increased expression of a tumor protective protein in a noninvasive manner. Such monitoring may be a means of detection of resistance to therapy, and it may be possible to use the monitoring findings to alter treatment strategies in real time. The tumor microenvironment seen at immunohistochemical analysis supports the hypothesized mechanism that the cytotoxic effects of radiation therapy that attract macrophages, causing the release of macrophage-derived inducible nitric oxide synthase and production of HIF-1alpha under aerobic conditions, also underlie chemotherapy. Such noninvasive imaging may be a means to development of therapeutic strategies that prevent HIF-1 up-regulation after chemotherapy treatments.

Authors
Viola, RJ; Provenzale, JM; Li, F; Li, C-Y; Yuan, H; Tashjian, J; Dewhirst, MW
MLA Citation
Viola, RJ, Provenzale, JM, Li, F, Li, C-Y, Yuan, H, Tashjian, J, and Dewhirst, MW. "In vivo bioluminescence imaging monitoring of hypoxia-inducible factor 1alpha, a promoter that protects cells, in response to chemotherapy." AJR Am J Roentgenol 191.6 (December 2008): 1779-1784.
PMID
19020250
Source
pubmed
Published In
AJR. American journal of roentgenology
Volume
191
Issue
6
Publish Date
2008
Start Page
1779
End Page
1784
DOI
10.2214/AJR.07.4060

Induction of the human heat shock promoter HSP70B by nutritional stress: implications for cancer gene therapy.

BACKGROUND: We designed and tested, in vitro, an adenoviral construct containing the feline interleukin-12 (IL-12) gene under control of the heat-inducible promoter HSP70B. This construct, AdhspfIL12, was used in a phase I trial in feline soft tissue sarcomas. During the course of our experiments, we noted that IL-12 was being produced in the transfected Crandell Feline Kidney (CrFK) cells under certain conditions even in the absence of hyperthermia. This observation was further explored to identify the cause of this unintended HSP70B induction. MATERIALS AND METHODS: We used real-time PCR as a sensitive method to quantitatively detect the presence of even small amounts of IL-12 mRNA. This served as a surrogate indicator of HSP70B induction. Various conditions were tested to induce the heat shock promoter, including nutritional deprivation, radiation and changes in pH. RESULTS: Nutritional stresses, specifically the absence of glucose and glutamine, could induce the heat shock promoter, thus, resulting in production of the downstream gene product. Other factors known to trigger the heat shock response, pH change, and reactive oxygen species production were also studied but were not found to contribute to heat shock promoter induction in our setting. CONCLUSIONS: The human heat shock promoter (HSP70B) is reported to be an efficient and tightly regulated promoter. We discovered, using sensitive real-time PCR techniques, that it can also be induced in response to cellular nutrient stresses. The pros and cons of this phenomenon and its implications for cancer gene therapy are discussed.

Authors
Siddiqui, F; Avery, PR; Li, C-Y; Zhang, X; LaRue, SM; Dewhirst, MW; Ullrich, RL
MLA Citation
Siddiqui, F, Avery, PR, Li, C-Y, Zhang, X, LaRue, SM, Dewhirst, MW, and Ullrich, RL. "Induction of the human heat shock promoter HSP70B by nutritional stress: implications for cancer gene therapy." Cancer Invest 26.6 (July 2008): 553-561.
PMID
18584345
Source
pubmed
Published In
Cancer Investigation (Informa)
Volume
26
Issue
6
Publish Date
2008
Start Page
553
End Page
561
DOI
10.1080/07357900701788015

Noninvasive imaging and quantification of epidermal growth factor receptor kinase activation in vivo

Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase (RTK) critical in tumor growth and a major target for anticancer drug development. However, thus far, there is no effective system to monitor its activities in vivo. Here, we report a novel approach to monitor EGFR activation based on the bifragment luciferase reconstitution system. The EGFR receptor and its interacting partner proteins (EGFR, growth factor receptor binding protein 2, and Src homology 2 domain-containing) were fused to NH2 terminal and COOH terminal fragments of the firefly luciferase. After establishing tumor xenograft from cells transduced with the reporter genes, we show that the activation of EGFR and its downstream factors could be quantified through optical imaging of reconstituted luciferase. Changes in EGFR activation could be visualized after radiotherapy or EGFR inhibitor treatment. Rapid and sustained radiation-induced EGFR activation and inhibitor-mediated signal suppression were observed in the same xenograft tumors over a period of weeks. Our data therefore suggest a new methodology where activities of RTKs can be imaged and quantified optically in mice. This approach should be generally applicable to study biological regulation of RTK, as well as to develop and evaluate novel RTK-targeted therapeutics. ©2008 American Association for Cancer Research.

Authors
Li, W; Li, F; Huang, Q; Frederick, B; Bao, S; Li, C-Y
MLA Citation
Li, W, Li, F, Huang, Q, Frederick, B, Bao, S, and Li, C-Y. "Noninvasive imaging and quantification of epidermal growth factor receptor kinase activation in vivo." Cancer Research 68.13 (2008): 4990-4997.
PMID
18593895
Source
scival
Published In
Cancer Research
Volume
68
Issue
13
Publish Date
2008
Start Page
4990
End Page
4997
DOI
10.1158/0008-5472.CAN-07-5984

Distinctive gene transduction efficiencies of commonly used viral vectors in the retina

The transduction efficiency and cell tropism of viral vectors rAAV2/1, rAAV2, Ad5, Ad5/F35, and Lentivirus were evaluated in retina. All viral vectors achieved efficient transduction in living rat retina. However, each vector showed distinctive efficiency in vitro especially for rAAV2/1, which displayed poor transduction in cultured retinal cells. Distinctive cell-specific GFP expression was observed in vivo and in vitro for the same viral vector. The cell-specific tropism was not strictly correlated with the correspondent distribution of viral receptors in retina. These results provided important insights into the selection of appropriate vectors when specific retinal diseases are considered for gene therapy. Copyright © Informa Healthcare USA, Inc.

Authors
Zhang, S-H; Wu, J-H; Wu, X-B; Dong, X-Y; Liu, X-J; Li, C-Y; Huang, Q
MLA Citation
Zhang, S-H, Wu, J-H, Wu, X-B, Dong, X-Y, Liu, X-J, Li, C-Y, and Huang, Q. "Distinctive gene transduction efficiencies of commonly used viral vectors in the retina." Current Eye Research 33.1 (2008): 81-90.
PMID
18214745
Source
scival
Published In
Current Eye Research (Informa)
Volume
33
Issue
1
Publish Date
2008
Start Page
81
End Page
90
DOI
10.1080/02713680701799408

Response of hypoxia-response element in human liver cancer cells to different microenvironments

Objective: Bel-7402 cells were stably transfected with a vector constructed with multiple copies of the hypoxia response- element (HRE) sequence of the human vascular endothelial growth factor (VEGF) gene and with the enhanced green fluorescent protein (EGFP) to establish a human hepatoma cell line Bel-7402/5HRE-EGFP. This paper aimed to study the responses of HRE in human liver cancer cells to different microenvironments by observing the changes in hypoxia-inducible factor 1 (HIF-1α) and vascular endothelial growth factor (VEGF) expression in Bel-7402/5HRE-EGFP cell lines under hypoxic conditions. Methods: The expression vector was constructed with 5 copies of HRE sequence and a minimal cytomegalovirus (CMV) as promoter and green fluorescent protein (GFP) as a reporter gene. The effect of different microenvironments such as hypoxia, H2 O2 or acidic pH on the activity of HRE in Bel-7402 cells and the changes in the expression levels of HIF-1α and VEGF under hypoxic condition were determined by using flow cytometry and immunohistochemical staining method. The association of the staining intensity and the distribution of pimonidazole, a hypoxic probe, with the expression and the distribution of HIF-1α, VEGF, and GFP were analyzed. The influence of hypoxia in tumor tissues of nude mice on the activity of HRE and expression of related genes were observed. Results: The HRE in liver cancer cells was very sensitive to hypoxia, which induces up-regulation of HIF-1α and VEGF expressions in tumor cells or in tumor tissues. Both distribution regions of HIF-1α and VEGF were almost the same. Conclusion: Hypoxia plays a pivotal role in controlling the expression of angiogenesis-related factors in human liver cancer cells.

Authors
Wang, F; Chen, X-F; Wei, F; Wu, J-H; Xie, K-C; Han, Y-H; Yi, M-Y; Li, C-Y; Huang, Q
MLA Citation
Wang, F, Chen, X-F, Wei, F, Wu, J-H, Xie, K-C, Han, Y-H, Yi, M-Y, Li, C-Y, and Huang, Q. "Response of hypoxia-response element in human liver cancer cells to different microenvironments." Tumor 28.5 (2008): 367-371.
Source
scival
Published In
Tumor
Volume
28
Issue
5
Publish Date
2008
Start Page
367
End Page
371
DOI
10.3781/j.issn.1000-7431.2008.05.001

Enhanced transduction and improved photoreceptor survival of retinal degeneration by the combinatorial use of rAAV2 with a lower dose of adenovirus

Recombinant adeno-associated virus (rAAV) is widely used in retinal gene therapy. Enhanced rAAV transduction may be important for better therapeutic effects in some retinal gene therapies. In this study, we examined the effects of adenovirus 5 (Ad5) on retina transduction mediated by rAAV2. Our results provide the first evidence that low levels of either replication-incompetent or conditional replication-competent Ad5 significantly enhance and accelerate transgene expression in human and rat retinal cells. This effect occurs principally at the transcriptional level, rather than through enhanced viral entry or DNA replication. In in vivo analyses with the SD rat, the Balb/c mouse, and the RCS rat, strong enhancement and acceleration of transgene expression, as well as therapeutic effects, were confirmed. Low levels of Ad5 may enhance the utility of rAAV2-mediated transduction strategies in future clinical investigations. © 2008 Elsevier Ltd. All rights reserved.

Authors
Wu, J; Zhang, S; Wu, X; Dong, X; Xu, P; Liu, X; Li, C; Huang, Q
MLA Citation
Wu, J, Zhang, S, Wu, X, Dong, X, Xu, P, Liu, X, Li, C, and Huang, Q. "Enhanced transduction and improved photoreceptor survival of retinal degeneration by the combinatorial use of rAAV2 with a lower dose of adenovirus." Vision Research 48.15 (2008): 1648-1654.
PMID
18513780
Source
scival
Published In
Vision Research
Volume
48
Issue
15
Publish Date
2008
Start Page
1648
End Page
1654
DOI
10.1016/j.visres.2008.04.019

Exploring the role of HIF-1 in early angiogenesis and response to radiotherapy.

The objective of this review is to examine the role that HIF-1 plays in the initiation of angiogenesis and in radiotherapy response. Although these two phenomena may at first seem unrelated, there are parallelisms to be drawn associated with the importance of reactive oxygen species in controlling the transcriptional activity of HIF-1, independently of its main driving force, hypoxia. Knowledge of the mechanisms underlying the control of HIF-1 leads to rationale for its inhibition in a range of clinical scenarios.

Authors
Dewhirst, MW; Cao, Y; Li, CY; Moeller, B
MLA Citation
Dewhirst, MW, Cao, Y, Li, CY, and Moeller, B. "Exploring the role of HIF-1 in early angiogenesis and response to radiotherapy." Radiother Oncol 83.3 (June 2007): 249-255. (Review)
PMID
17560674
Source
pubmed
Published In
Radiotherapy & Oncology
Volume
83
Issue
3
Publish Date
2007
Start Page
249
End Page
255
DOI
10.1016/j.radonc.2007.05.016

Systemic overexpression of angiopoietin-2 promotes tumor microvessel regression and inhibits angiogenesis and tumor growth.

Angiopoietin-2 (Ang-2) is a conditional antagonist and agonist for the endothelium-specific Tie-2 receptor. Although endogenous Ang-2 cooperates with vascular endothelial growth factor (VEGF) to protect tumor endothelial cells, the effect on tumor vasculature of high levels of exogenous Ang-2 with different levels of VEGF has not been studied in detail. Here, we report that systemic overexpression of Ang-2 leads to unexpected massive tumor vessel regression within 24 h, even without concomitant inhibition of VEGF. By impairing pericyte coverage of the tumor vasculature, Ang-2 destabilizes the tumor vascular bed while improving perfusion in surviving tumor vessels. Ang-2 overexpression transiently exacerbates tumor hypoxia without affecting ATP levels. Although sustained systemic Ang-2 overexpression does not affect tumor hypoxia and proliferation, it significantly inhibits tumor angiogenesis, promotes tumor apoptosis, and suppresses tumor growth. The similar antitumoral, antiangiogenic efficacy of systemic overexpression of Ang-2, soluble VEGF receptor-1, and the combination of both suggests that concomitant VEGF inhibition is not required for Ang-2-induced tumor vessel regression and growth delay. This study shows the important roles of Ang-2-induced pericyte dropout during tumor vessel regression. It also reveals that elevated Ang-2 levels have profound pleiotropic effects on tumor vessel structure, perfusion, oxygenation, and apoptosis.

Authors
Cao, Y; Sonveaux, P; Liu, S; Zhao, Y; Mi, J; Clary, BM; Li, C-Y; Kontos, CD; Dewhirst, MW
MLA Citation
Cao, Y, Sonveaux, P, Liu, S, Zhao, Y, Mi, J, Clary, BM, Li, C-Y, Kontos, CD, and Dewhirst, MW. "Systemic overexpression of angiopoietin-2 promotes tumor microvessel regression and inhibits angiogenesis and tumor growth." Cancer Res 67.8 (April 15, 2007): 3835-3844.
PMID
17440098
Source
pubmed
Published In
Cancer Research
Volume
67
Issue
8
Publish Date
2007
Start Page
3835
End Page
3844
DOI
10.1158/0008-5472.CAN-06-4056

Regulation of HIF-1alpha stability through S-nitrosylation.

Hypoxia-inducible factor 1 (HIF-1) is a master transcriptional factor. Under normal oxygen tension, HIF-1 activity is usually suppressed due to the rapid, oxygen-dependent degradation of one of its two subunits, HIF-1alpha. Here we report that normoxic HIF-1 activity can be upregulated through NO-mediated S-nitrosylation and stabilization of HIF-1alpha. In murine tumors, exposure to ionizing radiation stimulated the generation of NO in tumor-associated macrophages. As a result, the HIF-1alpha protein is S-nitrosylated at Cys533 (through "biotin switch" assay) in the oxygen-dependent degradation domain, which prevents its destruction. Importantly, this mechanism appears to be independent of the prolylhydroxylase-based pathway that is involved in oxygen-dependent regulation of HIF-1alpha. Selective disruption of this S-nitrosylation significantly attenuated both radiation-induced and macrophage-induced activation of HIF-1alpha. This interaction between NO and HIF-1 sheds new light on their involvement in tumor response to treatment as well as mammalian inflammation process in general.

Authors
Li, F; Sonveaux, P; Rabbani, ZN; Liu, S; Yan, B; Huang, Q; Vujaskovic, Z; Dewhirst, MW; Li, C-Y
MLA Citation
Li, F, Sonveaux, P, Rabbani, ZN, Liu, S, Yan, B, Huang, Q, Vujaskovic, Z, Dewhirst, MW, and Li, C-Y. "Regulation of HIF-1alpha stability through S-nitrosylation." Mol Cell 26.1 (April 13, 2007): 63-74.
PMID
17434127
Source
pubmed
Published In
Molecular Cell
Volume
26
Issue
1
Publish Date
2007
Start Page
63
End Page
74
DOI
10.1016/j.molcel.2007.02.024

A phase I trial of hyperthermia-induced interleukin-12 gene therapy in spontaneously arising feline soft tissue sarcomas.

Interleukin-12 (IL-12), a proinflammatory cytokine, shows anticancer properties. Systemically administered IL-12 causes dose-dependent toxicity. To achieve localized intratumoral gene expression, an adenoviral gene therapy vector with IL-12 controlled by a heat-inducible promoter (heat shock promoter 70B) was developed and tested in a phase I clinical trial in cats with spontaneously arising soft tissue sarcoma. A feasibility study was done in 16 cats with soft tissue sarcoma using murine IL-12 and/or enhanced green fluorescent protein adenoviral vectors under cytomegalovirus or heat shock promoter 70 control. Subsequently, we conducted a phase I clinical trial using an adenoviral feline IL-12 construct in 13 cats with soft tissue sarcoma. The soft tissue sarcomas were irradiated (48 Gy/16 fractions) followed by intratumoral injection of adenovirus. Twenty-four hours postinjection, tumors were heated (41 degrees C, 60 min). Tumor expression of feline IL-12 and IFN-gamma was determined. Cats were monitored for systemic toxicity. For the murine IL-12 construct, an association was noted between viral dose and murine IL-12 levels within tumor, whereas serum levels were minimal. Mild toxicity was noted at 10(11) plaque-forming units (pfu). With the feline IL-12 construct, high levels of feline IL-12 mRNA were detected in tumor biopsies with low or absent IFN-gamma mRNA following gene therapy. Hematologic and hepatic toxicities were noted at the highest viral doses and were associated with detection of IFN-gamma mRNA in tumor. It is possible to localize gene expression and limit systemic toxicity of IL-12 using the hyperthermia-induced gene therapy approach. The maximum tolerated dose of the feline IL-12 adenoviral vector was 10(10) pfu/tumor as dose-limiting toxicities were noted at the 4 x 10(10) pfu dose.

Authors
Siddiqui, F; Li, C-Y; Larue, SM; Poulson, JM; Avery, PR; Pruitt, AF; Zhang, X; Ullrich, RL; Thrall, DE; Dewhirst, MW; Hauck, ML
MLA Citation
Siddiqui, F, Li, C-Y, Larue, SM, Poulson, JM, Avery, PR, Pruitt, AF, Zhang, X, Ullrich, RL, Thrall, DE, Dewhirst, MW, and Hauck, ML. "A phase I trial of hyperthermia-induced interleukin-12 gene therapy in spontaneously arising feline soft tissue sarcomas." Mol Cancer Ther 6.1 (January 2007): 380-389.
PMID
17237297
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
6
Issue
1
Publish Date
2007
Start Page
380
End Page
389
DOI
10.1158/1535-7163.MCT-06-0342

Regulation of mammalian horizontal gene transfer by apoptotic DNA fragmentation.

Previously it was shown that horizontal DNA transfer between mammalian cells can occur through the uptake of apoptotic bodies, where genes from the apoptotic cells were transferred to neighbouring cells phagocytosing the apoptotic bodies. The regulation of this process is poorly understood. It was shown that the ability of cells as recipient of horizontally transferred DNA was enhanced by deficiency of p53 or p21. However, little is known with regard to the regulation of DNA from donor apoptotic cells. Here we report that the DNA fragmentation factor/caspase-activated DNase (DFF/CAD), which is the endonuclease responsible for DNA fragmentation during apoptosis, plays a significant role in regulation of horizontal DNA transfer. Cells with inhibited DFF/CAD function are poor donors for horizontal gene transfer (HGT) while their ability of being recipients of HGT is not affected.

Authors
Yan, B; Wang, H; Li, F; Li, C-Y
MLA Citation
Yan, B, Wang, H, Li, F, and Li, C-Y. "Regulation of mammalian horizontal gene transfer by apoptotic DNA fragmentation." Br J Cancer 95.12 (December 18, 2006): 1696-1700.
PMID
17146478
Source
pubmed
Published In
British Journal of Cancer
Volume
95
Issue
12
Publish Date
2006
Start Page
1696
End Page
1700
DOI
10.1038/sj.bjc.6603484

Tumor necrosis factor-alpha is a potent endogenous mutagen that promotes cellular transformation.

Tumor necrosis factor-alpha (TNF-alpha) is an important inflammation cytokine without known direct effect on DNA. In this study, we found that TNF-alpha can cause DNA damages through reactive oxygen species. The mutagenic effect of TNF-alpha is comparable with that of ionizing radiation. TNF-alpha treatment in cultured cells resulted in increased gene mutations, gene amplification, micronuclei formation, and chromosomal instability. Antioxidants significantly reduced TNF-alpha-induced genetic damage. TNF-alpha also induced oxidative stress and nucleotide damages in mouse tissues in vivo. Moreover, TNF-alpha treatment alone led to increased malignant transformation of mouse embryo fibroblasts, which could be partially suppressed by antioxidants. As TNF-alpha is involved in chronic inflammatory diseases, such as chronic hepatitis, ulcerative colitis, and chronic skin ulcers, and these diseases predispose the patients to cancer development, our results suggest a novel pathway through which TNF-alpha promotes cancer development through induction of gene mutations, in addition to the previously reported mechanisms, in which nuclear factor-kappaB activation was implicated.

Authors
Yan, B; Wang, H; Rabbani, ZN; Zhao, Y; Li, W; Yuan, Y; Li, F; Dewhirst, MW; Li, C-Y
MLA Citation
Yan, B, Wang, H, Rabbani, ZN, Zhao, Y, Li, W, Yuan, Y, Li, F, Dewhirst, MW, and Li, C-Y. "Tumor necrosis factor-alpha is a potent endogenous mutagen that promotes cellular transformation." Cancer Res 66.24 (December 15, 2006): 11565-11570.
PMID
17178846
Source
pubmed
Published In
Cancer Research
Volume
66
Issue
24
Publish Date
2006
Start Page
11565
End Page
11570
DOI
10.1158/0008-5472.CAN-06-2540

Anti-angiogenic effects of interleukin-12 delivered by a novel hyperthermia induced gene construct.

PURPOSE: Interleukin-12 (IL-12) is a pro-inflammatory cytokine possessing anti-cancer and anti-angiogenic properties. This study quantitatively assessed the anti-angiogenic effect of IL-12 delivered using an adenoviral vector with murine IL-12 placed under control of a heat shock promoter. This approach limits systemic toxicity by restricting IL-12 delivery locally to the tumour. The kinetics of the downstream cytokines interferon-gamma (IFN-gamma) and interferon inducible protein-10 (IP-10) and other molecules affecting angiogenesis, vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) were also studied. MATERIALS AND METHODS: 4T1 tumours were grown in Balb/C mice and the AdhspmIL-12 construct was injected intra-tumourally. The tumours were heated after 24 h using a water bath. At various time points post-heating the tumours were collected and quantitatively assessed for cytokine production and vascularity. RESULTS: A significant reduction was seen in the tumour vasculature of the treated group vs. the control group mice. Systemic effects of IL-12 were limited to generalized immunostimulation. No hepatoxicity was noted. CONCLUSIONS: This study suggests that IL-12 can be effectively delivered using a gene-based approach with a heat shock promoter. This results in quantitatively measurable anti-angiogenesis and general immunostimulation. The complex inter-play of other pro- and anti-angiogenic factors (IFN-gamma, IP-10, VEGF and PAI-1) was also studied.

Authors
Siddiqui, F; Ehrhart, EJ; Charles, B; Chubb, L; Li, C-Y; Zhang, X; Larue, SM; Avery, PR; Dewhirst, MW; Ullrich, RL
MLA Citation
Siddiqui, F, Ehrhart, EJ, Charles, B, Chubb, L, Li, C-Y, Zhang, X, Larue, SM, Avery, PR, Dewhirst, MW, and Ullrich, RL. "Anti-angiogenic effects of interleukin-12 delivered by a novel hyperthermia induced gene construct." Int J Hyperthermia 22.7 (November 2006): 587-606.
PMID
17079216
Source
pubmed
Published In
International Journal of Hyperthermia (Informa)
Volume
22
Issue
7
Publish Date
2006
Start Page
587
End Page
606
DOI
10.1080/02656730600983063

Apoptotic DNA fragmentation factor maintains chromosome stability in a P53-independent manner.

DNA fragmentation factor (DFF)/caspase-activated DNase (CAD) is responsible for DNA fragmentation, a hallmark event during apoptosis. Although DNA fragmentation is an evolutionarily conserved process across species, its biological function is not clearly understood. In this study, we constructed cell lines expressing a mutant ICAD (inhibitor of CAD) protein that is resistant to caspase cleavage and therefore constantly binds to DFF/CAD and inhibits DNA fragmentation. We found that irradiation of these cells led to increased chromosome aberrations and aneuploidy when compared with their parental controls. The increased chromosome instability is observed irrespective of cellular P53 status, suggesting that the effect of DFF/CAD is independent of P53. Inhibition of apoptotic DNA fragmentation resulted in increased clonogenic survival of irradiated cells and a delay in removal of cells with DNA damages induced by radiation, an effect similar to that in cells with p53 mutations. Consistent with DFF/CAD's effect on clonogenic survival, tumors established from cells deficient in DNA fragmentation showed enhanced growth in nude mice. Therefore, our results suggest that DFF/CAD plays an important and P53-independent role in maintaining chromosome stability and suppressing tumor development.

Authors
Yan, B; Wang, H; Wang, H; Zhuo, D; Li, F; Kon, T; Dewhirst, M; Li, C-Y
MLA Citation
Yan, B, Wang, H, Wang, H, Zhuo, D, Li, F, Kon, T, Dewhirst, M, and Li, C-Y. "Apoptotic DNA fragmentation factor maintains chromosome stability in a P53-independent manner." Oncogene 25.39 (August 31, 2006): 5370-5376.
PMID
16619042
Source
pubmed
Published In
Oncogene: Including Oncogene Reviews
Volume
25
Issue
39
Publish Date
2006
Start Page
5370
End Page
5376
DOI
10.1038/sj.onc.1209535

High intensity focused ultrasound-induced gene activation in solid tumors.

In this work, the activation of heat-sensitive trans-gene by high-intensity focused ultrasound (HIFU) in a tumor model was investigated. 4T1 cancer cells (2 x 10(6)) were inoculated subcutaneously in the hind limbs of Balb/C mice. The tumors were subsequently transducted on day 10 by intratumoral injection of a heat-sensitive adenovirus vector (Adeno-hsp70B-Luc at 2 x 10(8) pfu/tumor). On day 11, the tumors were heated to a peak temperature of 55, 65, 75, or 85 degrees C within 10-30 s at multiple sites around the center of the tumor by a 1.1- or 3.3-MHz HIFU transducer. Inducible luciferase gene expression was increased from 15-fold to 120-fold of the control group following 1.1-MHz HIFU exposure. Maximum gene activation (120-fold) was produced at a peak temperature of 65-75 degrees C one day following HIFU exposure and decayed to baseline within 7 days. HIFU-induced gene activation (75 degrees C-10 s) could be further improved by using a 3.3-MHz transducer and a dense scan strategy to 170-fold. Thermal stress, rather than nonthermal mechanical stress, was identified as the primary physical mechanism for HIFU-induced gene activation in vivo. Overall, these observations open up the possibility for combining HIFU thermal ablation with heat-regulated gene therapy for cancer treatment.

Authors
Liu, Y; Kon, T; Li, C; Zhong, P
MLA Citation
Liu, Y, Kon, T, Li, C, and Zhong, P. "High intensity focused ultrasound-induced gene activation in solid tumors." J Acoust Soc Am 120.1 (July 2006): 492-501.
PMID
16875245
Source
pubmed
Published In
The Journal of the Acoustical Society of America
Volume
120
Issue
1
Publish Date
2006
Start Page
492
End Page
501

A novel role of DNA fragmentation factor as a tumor suppressor through maintaining genomic stability.

Authors
Yan, B; Wang, H; Bedford, JS; Dewhirst, MW; Li, C
MLA Citation
Yan, B, Wang, H, Bedford, JS, Dewhirst, MW, and Li, C. "A novel role of DNA fragmentation factor as a tumor suppressor through maintaining genomic stability." June 20, 2006.
Source
wos-lite
Published In
Journal of Clinical Oncology
Volume
24
Issue
18
Publish Date
2006
Start Page
546S
End Page
546S

A novel role of DNA fragmentation factor as a tumor suppressor through maintaining genomic stability.

10023 Background: DNA fragmentation is a hallmark of apoptosis. However, the biological function of apoptotic DNA fragmentation remains unclear. Genes encoding the nuclease responsible for DNA fragmentation, DFF40/CAD and DFF45/ICAD, are deleted, mutated, or aberrantly expressed in many human tumor types. Abnormalities in this gene are associated with aggressive tumors and poor prognosis in cancer patients. Tumor-specific DFF45 gene mutations were identified in human tumors, indicating the involvement of this gene in tumor development.We studied genetic instability, cellular transformation and tumorigenesis in cells and mice deficient in DNA fragmentation. We applied two methods to inhibit DNA fragmentation, overexpressing a modified ICAD which inhibits DNA fragmentation during apoptosis in stable cell lines and disrupting cad gene in transgenic mice. Genetic instability was studied by gene amplification assay, mutation assay and cytogenetic analysis including chromosomal aberrations and translocations. Cellular transformation was studied by soft agar assay using CAD-/- MEF cells. Tumorigenesis in DFF/CAD-knockout mice was studied by radiation carcinogenesis and two-stage skin chemical carcinogenesis.(1) Human and mouse cancer cell lines with their CAD activity inhibited exhibited significantly more genetic instability under spontaneous or mutagen (ionizing radiation) induced conditions. These are reflected as elevated frequencies of chromosomal aberrations, gene amplifications, and gene mutations; (2) Mouse cells with targeted disruption of the cad gene exhibit a similar, increased level of genetic instability when the host animal is irradiated; (3) Mechanistically, CAD maintains genetic instability through the removal of cells with DNA damage, a role that is similar to genomic "gatekeepers" like p53; (4) CAD-null mouse embryo fibroblasts exhibited enhanced cellular transformation; (5) Significantly enhanced susceptibility to chemical and radiation-induced tumor development was observed in mice with targeted disruption of the CAD gene, indicating that it plays a role in suppressing tumor development.CAD plays an important role in maitaining genetic stability and suppressing tumor development. No significant financial relationships to disclose.

Authors
Yan, B; Wang, H; Bedford, JS; Dewhirst, MW; Li, C
MLA Citation
Yan, B, Wang, H, Bedford, JS, Dewhirst, MW, and Li, C. "A novel role of DNA fragmentation factor as a tumor suppressor through maintaining genomic stability." Journal of clinical oncology : official journal of the American Society of Clinical Oncology 24.18_suppl (June 2006): 10023-.
PMID
27955376
Source
epmc
Published In
Journal of Clinical Oncology
Volume
24
Issue
18_suppl
Publish Date
2006
Start Page
10023

Adenovirus Mediated GRP94/gp96 Expression in Treatment of Neuroblastoma

Authors
Liu, S; Zhu, J; Wang, H; Kon, T; Li, C-Y
MLA Citation
Liu, S, Zhu, J, Wang, H, Kon, T, and Li, C-Y. "Adenovirus Mediated GRP94/gp96 Expression in Treatment of Neuroblastoma." MOLECULAR THERAPY 13 (May 2006): S164-S164.
Source
wos-lite
Published In
Molecular Therapy
Volume
13
Publish Date
2006
Start Page
S164
End Page
S164

High Intensity Focused Ultrasound (HIFU) Induced Trans-Gene Activation in Solid Tumors

Authors
Liu, Y; Hu, Z; Lu, X; Kon, T; Li, C; Zhong, P
MLA Citation
Liu, Y, Hu, Z, Lu, X, Kon, T, Li, C, and Zhong, P. "High Intensity Focused Ultrasound (HIFU) Induced Trans-Gene Activation in Solid Tumors." MOLECULAR THERAPY 13 (May 2006): S368-S368.
Source
wos-lite
Published In
Molecular Therapy
Volume
13
Publish Date
2006
Start Page
S368
End Page
S368

Characterization of a recombinant adenovirus vector encoding heat-inducible feline interleukin-12 for use in hyperthermia-induced gene-therapy.

Interleukin-12 (IL-12) is a pro-inflammatory cytokine that has shown great promise as a therapeutic agent in experimental models of infectious disease and cancer. However, it is also a highly toxic molecule and for that reason has not been accepted readily into the clinic. A replication-deficient adenoviral vector was designed to deliver the feline interleukin-12 gene into tumour cells. The interleukin-12 gene has been placed under control of a heat inducible promoter, human heat shock promoter 70b, with the intent of spatially and temporally controlling the expression of IL-12, thus limiting its toxicity. In vitro, the transfection efficiency of the adenoviral vector, the effect of multiplicity of infection and the production of biologically active feline IL-12 were studied in the infected cells in response to a range of temperatures. This adenoviral vector will be a useful tool to examine the effects of intra-tumoural IL-12 delivery in a spontaneously occurring feline soft tissue sarcoma model.

Authors
Siddiqui, F; Li, C-Y; Zhang, X; Larue, SM; Dewhirst, MW; Ullrich, RL; Avery, PR
MLA Citation
Siddiqui, F, Li, C-Y, Zhang, X, Larue, SM, Dewhirst, MW, Ullrich, RL, and Avery, PR. "Characterization of a recombinant adenovirus vector encoding heat-inducible feline interleukin-12 for use in hyperthermia-induced gene-therapy." Int J Hyperthermia 22.2 (March 2006): 117-134.
PMID
16754596
Source
pubmed
Published In
International Journal of Hyperthermia (Informa)
Volume
22
Issue
2
Publish Date
2006
Start Page
117
End Page
134
DOI
10.1080/02656730500462309

A comparison of antiangiogenic therapies for the prevention of liver metastases.

Angiogenesis is essential for solid tumor growth. Although successful antiangiogenic therapies have been demonstrated in animal models, a systematic comparison of the efficacy of different antiangiogenic factors has not been described in the hepatic environment. To address this issue, CT26 murine colon carcinoma cells were transfected with retroviral vectors encoding murine endostatin (mEndostatin), human angiostatin (hAngiostatin), murine-soluble vascular endothelial growth factor receptor-2, (msFlk-1), or murine-soluble Tie2 (msTie2). The transfected cells were then subjected to another round of transfection with a luciferase cDNA-encoding retroviral vector. Expression of these putative antiangiogenic proteins inhibited the proliferation of human umbilical vein endothelial cells in vitro but not tumor cells. To examine effects on tumor growth in vivo, modified cells were delivered via intrasplenic injection into BALB/c mice to induce liver metastases. Tumor burden was measured weekly by bioluminescence. Growth of hepatic metastases in vivo was significantly reduced in mice that were administered cells expressing msTie2 (76% reduction compared with control cells 21 days after intrasplenic inoculation; P < 0.05). Similar results were observed with cells that expressed msFlk-1 and hAngiostatin. However, expression of mEndostatin had no significant effect on the growth of liver metastases compared with control animals. These findings indicate that multiple antiangiogenic pathways are necessary for the growth of hepatic metastases, and each of these pathways is a potential clinically relevant antiangiogenic target for the treatment of this disease.

Authors
Mi, J; Sarraf-Yazdi, S; Zhang, X; Cao, Y; Dewhirst, MW; Kontos, CD; Li, C-Y; Clary, BM
MLA Citation
Mi, J, Sarraf-Yazdi, S, Zhang, X, Cao, Y, Dewhirst, MW, Kontos, CD, Li, C-Y, and Clary, BM. "A comparison of antiangiogenic therapies for the prevention of liver metastases." J Surg Res 131.1 (March 2006): 97-104.
PMID
16242720
Source
pubmed
Published In
Journal of Surgical Research
Volume
131
Issue
1
Publish Date
2006
Start Page
97
End Page
104
DOI
10.1016/j.jss.2005.09.008

Effects of rate, volume, and dose of intratumoral infusion on virus dissemination in local gene delivery.

Recent studies have shown that up to 90% of viral vectors could disseminate to normal organs following intratumoral infusion. The amount of dissemination might be dependent on the infusion conditions. Therefore, we investigated the effects of infusion rate, volume, and dose on transgene expression in liver and tumor tissues after intratumoral infusion of an adenoviral vector encoding luciferase. Luciferase expression was determined through bioluminescence intensity measurement. We observed that the luciferase expression in the liver was independent of the infusion rate but increased with the infusion dose, whereas the luciferase expression in the tumor was a bell-shaped function of the infusion rate. The latter observation was consistent with the distribution pattern of Evans blue-labeled albumin after its solution was infused into tumors at the same infusion rates. We also observed that the infusion volume could affect luciferase expression in the tumor but not in the liver. These observations implied that virus dissemination was determined mainly by the infusion dose, whereas the amount of transgene expression in the tumor depended on the distribution volume of viral vectors in the tumor as well as the infusion dose.

Authors
Wang, Y; Wang, H; Li, C-Y; Yuan, F
MLA Citation
Wang, Y, Wang, H, Li, C-Y, and Yuan, F. "Effects of rate, volume, and dose of intratumoral infusion on virus dissemination in local gene delivery." Mol Cancer Ther 5.2 (February 2006): 362-366.
PMID
16505110
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
5
Issue
2
Publish Date
2006
Start Page
362
End Page
366
DOI
10.1158/1535-7163.MCT-05-0266

Pim-1 kinase inhibits the activation of reporter gene expression in Elk-1 and c-Fos reporting systems but not the endogenous gene expression: an artifact of the reporter gene assay by transient co-transfection.

We have studied the molecular mechanism and signal transduction of pim-1, an oncogene encoding a serine-threonine kinase. This is a true oncogene which prolongs survival and inhibits apoptosis of hematopoietic cells. In order to determine whether the effects of Pim-1 occur by regulation of the mitogen-activated protein kinase pathway, we used a transcriptional reporter assay by transient co-transfection as a screening method. In this study, we found that Pim-1 inhibited the Elk-1 and NFkappaB transcriptional activities induced by activation of the mitogen-activated protein kinase cascade in reporter gene assays. However, Western blots showed that the induction of Elk-1-regulated expression of endogenous c-Fos was not affected by Pim-1. The phosphorylation and activation of neither Erk1/2 nor Elk-1 was influenced by Pim-1. Also, in the gel shift assay, the pattern of endogenous NFkappaB binding to its probe was not changed in any manner by Pim-1. These data indicate that Pim-1 does not regulate the activation of Erk1/2, Elk-1 or NFkappaB. These contrasting results suggest a pitfall of the transient co-transfection reporter assay in analyzing the regulation of transcription factors outside of the chromosome context. It ensures that results from reporter gene expression assay should be verified by study of endogenous gene expression.

Authors
Yan, B; Wang, H; Kon, T; Li, C-Y
MLA Citation
Yan, B, Wang, H, Kon, T, and Li, C-Y. "Pim-1 kinase inhibits the activation of reporter gene expression in Elk-1 and c-Fos reporting systems but not the endogenous gene expression: an artifact of the reporter gene assay by transient co-transfection." Braz J Med Biol Res 39.2 (February 2006): 169-176.
PMID
16470303
Source
pubmed
Published In
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas / Sociedade Brasileira de Biofisica ... [et al.]
Volume
39
Issue
2
Publish Date
2006
Start Page
169
End Page
176

A unique role of the DNA fragmentation factor in maintaining genomic stability.

DNA fragmentation is a hallmark of apoptosis (programmed cell death). However, the biological function of apoptotic DNA fragmentation remains unclear. Here, we show that DNA fragmentation factor plays an important role for maintaining genomic stability. Inhibition or loss of the DNA fragmentation factor (DFF)/caspase-activated DNase (CAD), whose nuclease activity is responsible for digesting genomic DNA during apoptosis, led to significant increases in spontaneous or induced gene mutations, gene amplifications, and chromosomal instability in primary mouse cells and transformed human cell lines. The mechanism underlying genetic instability in DFF/CAD-deficient cells, at least in part, involves a small but significant elevation in the survival of cells exposed to ionizing radiation, suggesting that apoptotic DNA fragmentation factor contributes to genomic stability by ensuring the removal of cells that have suffered DNA damage. In support of this hypothesis are the observations of increased cellular transformation of mouse embryonic cells from the DFF/CAD-null mice and significantly enhanced susceptibility to radiation-induced carcinogenesis in these mice. These data, in combination with published reports on the existence of tumor-specific gene mutations/deletions in the DFF/CAD genes in human cancer samples, suggest that apoptotic DNA fragmentation factor is required for the maintenance of genetic stability and may play a role in tumor suppression.

Authors
Yan, B; Wang, H; Peng, Y; Hu, Y; Wang, H; Zhang, X; Chen, Q; Bedford, JS; Dewhirst, MW; Li, C-Y
MLA Citation
Yan, B, Wang, H, Peng, Y, Hu, Y, Wang, H, Zhang, X, Chen, Q, Bedford, JS, Dewhirst, MW, and Li, C-Y. "A unique role of the DNA fragmentation factor in maintaining genomic stability." Proc Natl Acad Sci U S A 103.5 (January 31, 2006): 1504-1509.
PMID
16432220
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
103
Issue
5
Publish Date
2006
Start Page
1504
End Page
1509
DOI
10.1073/pnas.0507779103

High intensity focused ultrasound induced gene activation in solid tumors

In this work, the feasibility of using high intensity focused ultrasound (HIFU) to activate trans-gene expression in a mouse tumor model was investigated. 4T1 cancer cells were implanted subcutaneously in the hind limbs of Balb/C mice and adenovirus luciferase gene vectors under the control of heat shock protein 70B promoter (Adeno-hsp70B-Luc) were injected intratumoraly for gene transfection. One day following the virus injection, the transfected tumors were heated to a peak temperature of 55, 65, 75, and 85°C, respectively, in 10s at multiple sites around the center of the tumor using a HIFU transducer operated at either 1.1-MHz (fundamental) or 3.3-MHz (3 rd harmonic) frequency. Inducible luciferase gene expression was found to vary from 15-fold to 120-fold of the control group following 1.1-MHz HIFU exposure. The maximum gene activation was produced at a peak temperature of 65∼75°C one day following HIFU exposure and decayed gradually to baseline level within 7 days. The inducible gene activation produced by 3.3-MHz HIFU exposure (75°C-10s) was found to be comparable to that produced by hyperthermia (42°C-30min). Altogether, these results demonstrate the feasibility of using HIFU as a simple and versatile physical means to regulate trans-gene expression in vivo. This unique feature may be explored in the future for a synergistic combination of HIFU-induced thermal ablation with heat-induced gene therapy for improved cancer therapy. © 2006 American Institute of Physics.

Authors
Liu, Y; Kon, T; Li, C; Zhong, P
MLA Citation
Liu, Y, Kon, T, Li, C, and Zhong, P. "High intensity focused ultrasound induced gene activation in solid tumors." AIP Conference Proceedings 829 (2006): 588-592.
Source
scival
Published In
AIP Conference Proceedings
Volume
829
Publish Date
2006
Start Page
588
End Page
592
DOI
10.1063/1.2205542

Abnormal gene expression profiles in unaffected parents of patients with hereditary-type retinoblastoma

The hereditary form of retinoblastoma (Rb) is associated with a germ line mutation in one RB allele and is characterized by the occurrence of multiple, bilateral Rb tumors and a predisposition to the development of second cancers. In an earlier study, we observed an unexpected hypersensitivity to ionizing radiation in skin fibroblasts derived from unaffected parents of children with hereditary Rb. In at least four of these five families, there was no family history of Rb, indicating a new germ line mutation. We hypothesize that the increased parental cell sensitivity to radiation may reflect the presence of an as yet unrecognized genetic abnormality occurring in one or both parents of children with Rb. In the present study, we use DNA microarray technology to determine whether differences in gene expression profiles occurred in the unaffected parents of patients with hereditary Rb relative to normal individuals. Microarray analyses were validated by quantitative reverse transcription-PCR measurements. A distinct difference was observed in the patterns of gene expression between unaffected Rb parents and normal controls. By use of the prediction analysis for microarrays and principal component analysis methodologies, significant differences between the two groups were identified when as few as nine genes were analyzed. Further study of this phenomenon may offer a new insight into the genetic mechanisms of Rb and perhaps more broadly in cancer biology. ©2006 American Association for Cancer Research.

Authors
Chuang, EY; Chen, X; Tsai, M-H; Yan, H; Li, C-Y; Mitchell, JB; Nagasawa, H; Wilson, PF; Peng, Y; Fitzek, MM; Bedford, JS; Little, JB
MLA Citation
Chuang, EY, Chen, X, Tsai, M-H, Yan, H, Li, C-Y, Mitchell, JB, Nagasawa, H, Wilson, PF, Peng, Y, Fitzek, MM, Bedford, JS, and Little, JB. "Abnormal gene expression profiles in unaffected parents of patients with hereditary-type retinoblastoma." Cancer Research 66.7 (2006): 3428-3433.
PMID
16585164
Source
scival
Published In
Cancer Research
Volume
66
Issue
7
Publish Date
2006
Start Page
3428
End Page
3433
DOI
10.1158/0008-5472.CAN-05-2847

High intensity focused ultrasound-induced gene activation in sublethally injured tumor cells in vitro.

Cultured human cervical cancer (HeLa) and rat mammary carcinoma (R3230Ac) cells were transfected with vectors encoding green fluorescent protein (GFP) under the control of hsp70B promoter. Aliquots of 10-microl transfected cells (5 x 10(7) cells/ml) were placed in 0.2-ml thin-wall polymerase chain reaction tubes and exposed to 1.1-MHz high intensity focused ultrasound (HIFU) at a peak negative pressure P- = 2.68 MPa. By adjusting the duty cycle of the HIFU transducer, the cell suspensions were heated to a peak temperature from 50 to 70 degrees C in 1-10 s. Exposure dependent cell viability and gene activation were evaluated. For a 5-s HIFU exposure, cell viability dropped from 95% at 50 degrees C to 13% at 70 degrees C. Concomitantly, gene activation in sublethally injured tumor cells increased from 4% at 50 degrees C to 41% at 70 degrees C. A similar trend was observed at 60 degrees C peak temperature as the exposure time increased from 1 to 5 s. Further increase of exposure duration to 10 s led to significantly reduced cell viability and lower overall gene activation in exposed cells. Altogether, maximum HIFU-induced gene activation was achieved at 60 degrees C in 5 s. Under these experimental conditions, HIFU-induced gene activation was found to be produced primarily by thermal rather than mechanical stresses.

Authors
Liu, Y; Kon, T; Li, C; Zhong, P
MLA Citation
Liu, Y, Kon, T, Li, C, and Zhong, P. "High intensity focused ultrasound-induced gene activation in sublethally injured tumor cells in vitro." J Acoust Soc Am 118.5 (November 2005): 3328-3336.
PMID
16334906
Source
pubmed
Published In
The Journal of the Acoustical Society of America
Volume
118
Issue
5
Publish Date
2005
Start Page
3328
End Page
3336

Enhancement of cancer radiation therapy by use of adenovirus-mediated secretable glucose-regulated protein 94/gp96 expression.

Tumor-derived glucose-regulated protein 94 (GRP94/gp96) has shown great promise as a tumor vaccine. However, current protein-based approaches require the availability of large quantities of tumor tissue, which are often not possible. In addition, the efficacy of immunotherapy is often not ideal when used alone. In this study, we explored the therapeutic efficacy of a combined GRP94/gp96-based genetic immunotherapy and radiation therapy strategy in the weakly immunogenic and highly metastatic 4T1 murine mammary cancer model. An adenovirus encoding a modified, secretable form of GRP94 gene (AdsGRP94) was constructed and evaluated in various antitumor experiments. Lethally irradiated, virus-infected cells were used as vaccines. Adenoviral vectors were also injected directly into tumors in conjunction with tumor irradiation. Vaccination with lethally irradiated, AdsGRP94-infected 4T1 cells completely prevented subsequent tumor growth from challenge inoculations of as many as 10(7) cells per mouse. In established tumor models, vaccinations alone had minimal effect on local and metastatic tumor growth. However, when vaccination was combined with radiation therapy and i.t. AdsGRP94 injections, local tumor growth and pulmonary metastasis were markedly inhibited. In some cases, complete tumor regression was observed. In these cases, the mice were resistant to subsequent tumor challenge and remain tumor free up to 10 months after initial therapy. Our results indicate that combined AdsGRP94-based immunotherapy and radiation therapy may be a potentially effective strategy for cancer treatment.

Authors
Liu, S; Wang, H; Yang, Z; Kon, T; Zhu, J; Cao, Y; Li, F; Kirkpatrick, J; Nicchitta, CV; Li, C-Y
MLA Citation
Liu, S, Wang, H, Yang, Z, Kon, T, Zhu, J, Cao, Y, Li, F, Kirkpatrick, J, Nicchitta, CV, and Li, C-Y. "Enhancement of cancer radiation therapy by use of adenovirus-mediated secretable glucose-regulated protein 94/gp96 expression." Cancer Res 65.20 (October 15, 2005): 9126-9131.
PMID
16230366
Source
pubmed
Published In
Cancer Research
Volume
65
Issue
20
Publish Date
2005
Start Page
9126
End Page
9131
DOI
10.1158/0008-5472.CAN-05-0945

A novel method for viral gene delivery in solid tumors.

Intratumoral infusion is the most commonly used method for viral gene delivery in clinical trials for cancer treatment. However, a potential problem in this approach is that viral vectors may disseminate from tumor to normal tissues during and after the infusion. To reduce the dissemination, we developed a novel method based on a biocompatible polymer, poloxamer 407, which could significantly increase the viscosity of virus suspension when the temperature was changed from 4 degrees C to 37 degrees C. With this method, we could significantly increase transgene expression in solid tumors and reduce virus dissemination by 2 orders of magnitude after intratumoral infusion of adenoviral vectors. The mechanism of reduction was likely to be that the viscous poloxamer solution blocked convection of viral vectors in the interstitial space and the lumen of microvessels in the vicinity of the infusion site. This method has a potential to be used in the clinic for enhancing efficacy and reducing toxicity in viral gene therapy.

Authors
Wang, Y; Liu, S; Li, C-Y; Yuan, F
MLA Citation
Wang, Y, Liu, S, Li, C-Y, and Yuan, F. "A novel method for viral gene delivery in solid tumors." Cancer Res 65.17 (September 1, 2005): 7541-7545.
PMID
16140915
Source
pubmed
Published In
Cancer Research
Volume
65
Issue
17
Publish Date
2005
Start Page
7541
End Page
7545
DOI
10.1158/0008-5472.CAN-05-1112

Pleiotropic effects of HIF-1 blockade on tumor radiosensitivity.

We have previously shown that radiation increases HIF-1 activity in tumors, causing significant radioprotection of the tumor vasculature. The impact that HIF-1 activation has on overall tumor radiosensitivity, however, is unknown. We reveal here that HIF-1 plays an important role in determining tumor radioresponsiveness through regulating four distinct processes. By promoting ATP metabolism, proliferation, and p53 activation, HIF-1 has a radiosensitizing effect on tumors. Through stimulating endothelial cell survival, HIF-1 promotes tumor radioresistance. As a result, the net effect of HIF-1 blockade on tumor radioresponsiveness is highly dependent on treatment sequencing, with "radiation first" strategies being significantly more effective than the alternative. These data provide a strong rationale for pursuing sequence-specific combinations of HIF-1 blockade and conventional therapeutics.

Authors
Moeller, BJ; Dreher, MR; Rabbani, ZN; Schroeder, T; Cao, Y; Li, CY; Dewhirst, MW
MLA Citation
Moeller, BJ, Dreher, MR, Rabbani, ZN, Schroeder, T, Cao, Y, Li, CY, and Dewhirst, MW. "Pleiotropic effects of HIF-1 blockade on tumor radiosensitivity." Cancer Cell 8.2 (August 2005): 99-110.
PMID
16098463
Source
pubmed
Published In
Cancer Cell
Volume
8
Issue
2
Publish Date
2005
Start Page
99
End Page
110
DOI
10.1016/j.ccr.2005.06.016

Observation of incipient tumor angiogenesis that is independent of hypoxia and hypoxia inducible factor-1 activation.

It is well established that hypoxia potently stimulates tumor angiogenesis by activating hypoxia inducible factor-1 (HIF-1)-induced proangiogenic factors, such as vascular endothelial growth factor. However, very little is known about the role of hypoxia in incipient angiogenesis in avascular tumors during their early stages of growth. To noninvasively investigate the functional significance of hypoxia and HIF-1 activation in incipient tumor angiogenesis, we genetically engineered HCT116 human colon carcinoma cells and 4T1 mouse mammary carcinoma cells with constitutively expressed red fluorescence protein as a tumor marker and green fluorescence protein (GFP) as a reporter for hypoxia and HIF-1 activation. The accuracy of GFP fluorescence in reporting hypoxia was confirmed by flow cytometry analysis and by immunohistochemical comparison with pimonidazole, a well-established hypoxia marker drug. Mouse dorsal skin-fold window chambers showed that incipient angiogenesis preceded a detectable level of hypoxia. The detectable levels of hypoxia were spatially and temporally related with more intensive secondary angiogenesis following the initial onset of new vessel formation. Selective killing of hypoxic cells by tirapazamine efficiently eliminated or delayed the detection of hypoxic cells, but it did not significantly delay the onset of incipient angiogenesis. These findings provide the first in vivo evidence that incipient tumor angiogenesis may not depend on hypoxia or HIF-1 activation. This is in contrast to the clear role of hypoxia in driving angiogenesis once initial tumor microvessel formation has occurred.

Authors
Cao, Y; Li, C-Y; Moeller, BJ; Yu, D; Zhao, Y; Dreher, MR; Shan, S; Dewhirst, MW
MLA Citation
Cao, Y, Li, C-Y, Moeller, BJ, Yu, D, Zhao, Y, Dreher, MR, Shan, S, and Dewhirst, MW. "Observation of incipient tumor angiogenesis that is independent of hypoxia and hypoxia inducible factor-1 activation." Cancer Res 65.13 (July 1, 2005): 5498-5505.
PMID
15994919
Source
pubmed
Published In
Cancer Research
Volume
65
Issue
13
Publish Date
2005
Start Page
5498
End Page
5505
DOI
10.1158/0008-5472.CAN-04-4553

Expression of dominant negative Rho-binding domain of Rho-kinase in organ cultured human eye anterior segments increases aqueous humor outflow.

PURPOSE: Based on pharmacological inhibition of activity, a role has been proposed for Rho-kinase in the modulation of aqueous outflow and intraocular pressure (IOP). This study employed a molecular approach to specifically address the role of Rho-kinase in the modulation of aqueous humor outflow. METHODS: Adenoviral vectors expressing green fluorescent protein alone (Ad-GFP) or the dominant negative Rho-binding domain of Rho-kinase and GFP (Ad-DNRK-GFP) were utilized in these experiments. Human and porcine primary trabecular meshwork (TM) cells were infected with 30 MOI (multiplicity of infection) of Ad-GFP alone or with Ad-DNRK-GFP. Changes in cell shape, actomyosin cytoskeletal integrity, and the status of myosin light chain (MLC) phosphorylation were evaluated. The aqueous outflow facility was determined in organ cultured anterior segments of human cadaver eyes infected with 10(7) pfu adenoviral vectors (Ad-GFP or Ad-DNRK-GFP) using a constant flow perfusion system. RESULTS: Expression of DNRK resulted in changes in cell shape (cell rounding, cell-cell detachment) and decreased actin stress fiber and focal adhesion staining in TM cells. These cellular changes were associated with substantially reduced myosin light chain phosphorylation. Additionally, organ cultured human eye anterior segments infected with Ad-DNRK-GFP exhibited a significant increase in the outflow facility (80%, n=9) compared to control anterior segments infected with Ad-GFP (5%). CONCLUSIONS: This study demonstrated that specific inhibition of Rho-kinase activity in trabecular meshwork cells led to alterations in cell shape and presumed contractile properties, and we hypothesize that these morphological and contractile events underlie the observed effects of dominant negative Rho-kinase on the aqueous humor outflow facility. These data provide molecular evidence for the hypothesis of Rho-kinase being a potential cellular target involved in the regulation of aqueous humor outflow resistance, with implications for novel glaucoma therapy.

Authors
Rao, PV; Deng, P; Maddala, R; Epstein, DL; Li, C-Y; Shimokawa, H
MLA Citation
Rao, PV, Deng, P, Maddala, R, Epstein, DL, Li, C-Y, and Shimokawa, H. "Expression of dominant negative Rho-binding domain of Rho-kinase in organ cultured human eye anterior segments increases aqueous humor outflow. (Published online)" Mol Vis 11 (April 27, 2005): 288-297.
PMID
15889013
Source
pubmed
Published In
Molecular vision
Volume
11
Publish Date
2005
Start Page
288
End Page
297

Characterisation of systemic dissemination of nonreplicating adenoviral vectors from tumours in local gene delivery.

Systemic virus dissemination is a potential problem during local gene delivery in solid tumours. However, the kinetics and pathways of the dissemination have not been well characterised during the first 24 h after the infusion is started. To this end, we infused adenoviral vectors for luciferase or enhanced green fluorescence protein into three different tumour models in mice. During and/or after the infusion, we determined the amount of adenoviruses in the tumour, blood, and liver, and examined the transgene expression in the liver, lung, blood, and tumour. In addition, we intravenously injected tumour cells expressing luciferase and examined the biodistribution of these cells in the body. We observed transgene expression in the liver and tumour at 24 h after the infusion, but could not detect transgene expression in the blood and lung. The peak concentration of viral vectors in the plasma occurred during the intratumoral infusion. At 10 min after the infusion, few viral vectors remained in the blood and the ratio of copy numbers of adenoviruses between liver and tumour was > 2 in 80% and > or = 10 in 40% of the mice. Most tumour cells injected intravenously accumulated in the lung within the first 24 h. Taken together, these data indicated that systemic virus dissemination occurred mainly during the first 10 min after the intratumoral infusion was started, and that the dissemination was due to infusion-induced convective transport of viral vectors into leaky tumour microvessels.

Authors
Wang, Y; Yang, Z; Liu, S; Kon, T; Krol, A; Li, C-Y; Yuan, F
MLA Citation
Wang, Y, Yang, Z, Liu, S, Kon, T, Krol, A, Li, C-Y, and Yuan, F. "Characterisation of systemic dissemination of nonreplicating adenoviral vectors from tumours in local gene delivery." Br J Cancer 92.8 (April 25, 2005): 1414-1420.
PMID
15812558
Source
pubmed
Published In
British Journal of Cancer
Volume
92
Issue
8
Publish Date
2005
Start Page
1414
End Page
1420
DOI
10.1038/sj.bjc.6602494

Focal gene induction in the liver of rats by a heat-inducible promoter using focused ultrasound hyperthermia: Preliminary results

Objective: We sought to examine high-intensity focused ultrasound (HIFU)-induced hyperthermia in the liver of a rat model to focally induce green-fluorescent protein (GFP). Materials and Methods: A total of 25 Copenhagen rats were included in this study. Rats were divided into groups treated with an adenovirus coding for green fluorescent protein (GFP) under the control of a hsp70B promoter and a CMV promoter. Ad-CMV-GFP-treated rats served as positive control. Untreated controls only subjected to MRI ± HIFU-treatment served to find out optimal power of HIFU in the target area of the liver. Temperature was noninvasively monitored by temperature sensitive magnetic resonance imaging (MRI). Results: Rats treated with Ad-hsp70B-GFP demonstrated localized gene induction within the liver parenchyma, in good correlation with MRI and histology. Applying an acoustic power of 1.92 W a relatively uniform focal temperature up to 42 ± 5°C within the liver parenchyma could be documented. 3 × 109 plaque-forming units proved to account for a very homogeneous liver infection. Number of fluorescent cells in the region of hyperthermia was similar to the control group treated with Ad-CMV-GFP. Conclusion: Using the introduced parameters spatially controlled gene induction within a parenchymal organ such as the liver in rats using HIFU under control of MRI is feasible. Copyright © 2005 by Lippincott Williams & Wilkins.

Authors
Plathow, C; Lohr, F; Divkovic, G; Rademaker, G; Farhan, N; Peschke, P; Zuna, I; Debus, J; Claussen, CD; Kauczor, H-U; Li, CY; Jenne, J; Huber, P
MLA Citation
Plathow, C, Lohr, F, Divkovic, G, Rademaker, G, Farhan, N, Peschke, P, Zuna, I, Debus, J, Claussen, CD, Kauczor, H-U, Li, CY, Jenne, J, and Huber, P. "Focal gene induction in the liver of rats by a heat-inducible promoter using focused ultrasound hyperthermia: Preliminary results." Investigative Radiology 40.11 (2005): 729-735.
PMID
16230906
Source
scival
Published In
Investigative Radiology
Volume
40
Issue
11
Publish Date
2005
Start Page
729
End Page
735
DOI
10.1097/01.rli.0000184763.62578.06

Cytokine and immuno-gene therapy for solid tumors.

Despite recent progress in our understanding of cancer biology and in many areas of cancer treatment, the success rate for cancer therapy remains dismal. Immunotherapy for cancer has long been an exciting field for many cancer researchers due to the possibility to mobilize the body's own immune system to eradicate cancer not only locally but also systemically. Since its initial discovery, cytokine-based immunotherapy has been vigorously and extensively investigated for cancer treatment due to the perception of it as a relatively easily purifiable, injectable form of cancer treatment agent. However, so far most cytokine-based therapy trials have fallen short of expectations. One of main obstacles is the difficulty to achieve therapeutically relevant dosage in patients without generating excessive normal tissue toxicity. The emergence of novel gene therapy approach to deliver therapeutic cytokine to tumors locally generated great excitement since it has the potential of generating sustained high local concentration of immunostimulatory cytokine without raising the systemic levels of the cytokines, which is responsible for most of the observed toxicity. In this review, we will attempt to provide an overview of the field and discuss some of the problems associated with cytokine-based immuno-gene therapy and potential solutions.

Authors
Li, C-Y; Huang, Q; Kung, H-F
MLA Citation
Li, C-Y, Huang, Q, and Kung, H-F. "Cytokine and immuno-gene therapy for solid tumors." Cellular & molecular immunology. 2.2 (2005): 81-91.
PMID
16191413
Source
scival
Published In
Cellular & molecular immunology.
Volume
2
Issue
2
Publish Date
2005
Start Page
81
End Page
91

Enhancement of hypoxia-induced tumor cell death in vitro and radiation therapy in vivo by use of small interfering RNA targeted to hypoxia-inducible factor-1alpha.

Hypoxia-inducible factor-1alpha (HIF-1alpha) is an important transcriptional factor that is activated when mammalian cells experience hypoxia, a tumor microenvironmental condition that plays pivotal roles in tumor progression and treatment. In this study, we examined the idea of down-regulating HIF-1alpha in tumor cells for therapeutic gain. We show that the expression levels of HIF-1alpha can be significantly attenuated by use of the recently established small interfering RNA technology in combination with adenovirus-mediated gene transfer. Down-regulation of the HIF-1alpha protein enhanced hypoxia-mediated tumor cell apoptosis in vitro. Subcutaneous tumor growth was also prevented from cells with attenuated HIF-1alpha expression. In addition, intratumoral injection of adenovirus encoding the HIF-1alpha-targeted small interfering RNA had a small but significant effect on tumor growth when combined with ionizing radiation. Therefore, our results provide proof of HIF-1alpha as an effective target for anticancer therapy. They also suggest that an adenovirus-based small interfering RNA gene transfer approach may be a potentially effective adjuvant strategy for cancer treatment.

Authors
Zhang, X; Kon, T; Wang, H; Li, F; Huang, Q; Rabbani, ZN; Kirkpatrick, JP; Vujaskovic, Z; Dewhirst, MW; Li, C-Y
MLA Citation
Zhang, X, Kon, T, Wang, H, Li, F, Huang, Q, Rabbani, ZN, Kirkpatrick, JP, Vujaskovic, Z, Dewhirst, MW, and Li, C-Y. "Enhancement of hypoxia-induced tumor cell death in vitro and radiation therapy in vivo by use of small interfering RNA targeted to hypoxia-inducible factor-1alpha." Cancer Res 64.22 (November 15, 2004): 8139-8142.
PMID
15548675
Source
pubmed
Published In
Cancer Research
Volume
64
Issue
22
Publish Date
2004
Start Page
8139
End Page
8142
DOI
10.1158/0008-5472.CAN-03-2301

The relationship between hypoxia and angiogenesis.

Recent studies have generated a large amount of data supporting the hypothesis that hypoxia drives tumor angiogenesis. The relationship between the two is often considered a matter of supply and demand: ineffectively-vascularized tumor tissue becomes hypoxic, stimulating neoangiogenesis to improve the influx of oxygen, thereby diminishing the angiogenic drive. Although this paradigm is logically pleasing, much of what is known about tumor biology argues against such a straightforward relationship. In fact, some preclinical data convincingly shows that tumor hypoxia and angiogenesis do not always go hand in hand. It is important to begin to explore means of reconciling these discrepancies. Although poor oxygenation is a strong stimulus for tumor angiogenesis, (1) the pathogenesis of tumor hypoxia is much more complicated than the supply-demand paradigm lets on and (2) hypoxia is not necessarily sufficient or necessary for neovascularization to occur. These subtleties may help to explain why so much data disagrees with the current hypoxia-angiogenesis model and may begin to build a better understanding of the role hypoxia plays in tumor vascularization. This article will review what is known about hypoxia and angiogenesis in nononcological processes and will apply these lessons to tumor biology to more deeply describe their relationship.

Authors
Moeller, BJ; Cao, Y; Vujaskovic, Z; Li, CY; Haroon, ZA; Dewhirst, MW
MLA Citation
Moeller, BJ, Cao, Y, Vujaskovic, Z, Li, CY, Haroon, ZA, and Dewhirst, MW. "The relationship between hypoxia and angiogenesis." Semin Radiat Oncol 14.3 (July 2004): 215-221. (Review)
PMID
15254864
Source
pubmed
Published In
Seminars in Radiation Oncology
Volume
14
Issue
3
Publish Date
2004
Start Page
215
End Page
221
DOI
10.1016/j.semradonc.2004.04.005

Antitumoral action of interferons and interleukins in combination with radiotherapy. Part II: Radiobiological and immunologic strategies

Background: Combined tumor treatment with cytokines, e.g., interferons (IFN), and radiotherapy was initially of phenomenological nature but has increasingly been based on a radiobiological rationale. However, an improved understanding of the complex interactions of the cytokine network within the immune system warrants the rationale for such studies to be reviewed. Methods: Based on published clinical studies, the results of treatment with interferons in combination with radiotherapy are reviewed. New strategies for antitumoral application of cytokines, illustrated by interleukin-(IL-)2 and IL-12 in preclinical and clinical studies, are presented. Results: The initially high expectations regarding the antitumoral action of IFN-α, IFN-β and IFN-γ in combination with radiotherapy have, with few exceptions, not been fulfilled. In particular, toxicity has been a problem after systemic application. Recent advances in immunology, however, have emphasized the importance of local interactions between antigen-presenting cells and effector cells such as natural killer (NK) cells and cytotoxic T-lymphocytes in the immune reaction against tumors. Preclinical studies with IL-2 und IL-12 have shown efficacy mainly against early metastases, but immune reactions against primary tumors have also been observed. Furthermore, the method and timing of the application have proven to be critical. Conclusion: A few positive clinical studies give cause for hope that a therapeutic benefit may be achieved by targeted, local application of cytokines. Recent preclinical studies indicate the importance of cellular cytokine production in the interaction between the components of the immune system. Gene therapy might contribute to reduce the toxicity associated with cytokine treatment.

Authors
Herskind, C; Fleckenstein, K; Lohr, J; Li, CY; Wenz, F; Lohr, F
MLA Citation
Herskind, C, Fleckenstein, K, Lohr, J, Li, CY, Wenz, F, and Lohr, F. "Antitumoral action of interferons and interleukins in combination with radiotherapy. Part II: Radiobiological and immunologic strategies." Strahlentherapie und Onkologie 180.6 (June 1, 2004): 331-339. (Review)
PMID
15175867
Source
scopus
Published In
Strahlentherapie und Onkologie
Volume
180
Issue
6
Publish Date
2004
Start Page
331
End Page
339
DOI
10.1007/s00066-004-8119-1

Radiation activates HIF-1 to regulate vascular radiosensitivity in tumors: role of reoxygenation, free radicals, and stress granules.

Through a poorly understood mechanism, tumors respond to radiation by secreting cytokines capable of inhibiting apoptosis in endothelial cells, thereby diminishing treatment response by minimizing vascular damage. We reveal here that this pathway is governed by a major angiogenesis regulator, HIF-1. Following radiotherapy, tumor reoxygenation leads to: (1) nuclear accumulation of HIF-1 in response to reactive oxygen, and (2) enhanced translation of HIF-1-regulated transcripts secondary to stress granule depolymerization. The resulting increase in HIF-1-regulated cytokines enhances endothelial cell radioresistance. Inhibiting postradiation HIF-1 activation significantly increases tumor radiosensitivity as a result of enhanced vascular destruction. These data describe novel pathways contributing significantly to our understanding of HIF-1 regulation which may be major determinants of tumor radiosensitivity, potentially having high clinical relevance.

Authors
Moeller, BJ; Cao, Y; Li, CY; Dewhirst, MW
MLA Citation
Moeller, BJ, Cao, Y, Li, CY, and Dewhirst, MW. "Radiation activates HIF-1 to regulate vascular radiosensitivity in tumors: role of reoxygenation, free radicals, and stress granules." Cancer Cell 5.5 (May 2004): 429-441.
PMID
15144951
Source
pubmed
Published In
Cancer Cell
Volume
5
Issue
5
Publish Date
2004
Start Page
429
End Page
441

GW112, a novel antiapoptotic protein that promotes tumor growth.

GW112 is a novel gene that has little homology to other known genes. It is overexpressed in a number of human tumor types, especially in those of the digestive system. We show here that GW112 is associated with GRIM-19, a protein known to be involved in regulating cellular apoptosis. Functionally, GW112 could significantly attenuate the ability of GRIM19 to mediate retinoic acid-IFN-beta-mediated cellular apoptosis and apoptosis-related gene expression. In addition, GW112 demonstrated strong antiapoptotic effects in tumor cells treated with other stress exposures such as hydrogen peroxide. Finally, forced overexpression of GW112 in murine prostate tumor cells led to more rapid tumor formation in a syngeneic host. Taken together, our data suggest that GW112 is an important regulator of cell death that plays important roles in tumor cell survival and tumor growth.

Authors
Zhang, X; Huang, Q; Yang, Z; Li, Y; Li, C-Y
MLA Citation
Zhang, X, Huang, Q, Yang, Z, Li, Y, and Li, C-Y. "GW112, a novel antiapoptotic protein that promotes tumor growth." Cancer Res 64.7 (April 1, 2004): 2474-2481.
PMID
15059901
Source
pubmed
Published In
Cancer Research
Volume
64
Issue
7
Publish Date
2004
Start Page
2474
End Page
2481

Antitumoral Action of Interferons and Interleukins in Combination with Radiotherapy. Part I: Immunologic Basis

Background: During the last 2 decades, cytokines such as interferons (IFN) have been used to modulate tumor response in radiotherapy. Initially, the focus was on antiviral and radiosensitizing effects of interferons but increasingly, the function of interferons and interleukins (IL) within the immune response to tumor cells is becoming important. Method: The cellular immune response toward tumor cells is reviewed. The role of cytokines in antigen presentation and activation of effector cells and their interactions with radiation are described. Preclinical strategies of the antitumor actions of cytokines are presented and discussed based on the induction of IFN-γ by IL-12. Results: Recent advances in immunology have demonstrated the importance of local interactions between antigen-presenting cells (APC) and effector cells such as natural killer (NK) cells and T-lymphocytes for an effective immune reaction against tumors. Interferons stimulate such interactions, while IL-2 plays a central role in the activation of NK cells and T-lymphocytes. The interactions between APC and effector cells are suppressed by many tumors but can be stimulated by irradiation. Since systemic applications of interferons is quite toxic, present strategies aim at local expression, e.g., the induction of IFN-γ expression in Th1 cells by IL-12. Conclusion: The improved understanding of immunologic mechanisms has emphasized the role of the cytokine network in the interaction between tumor cells and effector cells such as NK cells and T-lymphocytes. This opens new possibilities for the application of cytokines as biological response modifiers, which may eventually help widening the therapeutic window in radiotherapy.

Authors
Herskind, C; Fleckenstein, K; Lohr, J; Li, CY; Wenz, F; Lohr, F
MLA Citation
Herskind, C, Fleckenstein, K, Lohr, J, Li, CY, Wenz, F, and Lohr, F. "Antitumoral Action of Interferons and Interleukins in Combination with Radiotherapy. Part I: Immunologic Basis." Strahlentherapie und Onkologie 180.4 (April 1, 2004): 187-193. (Review)
PMID
15057428
Source
scopus
Published In
Strahlentherapie und Onkologie
Volume
180
Issue
4
Publish Date
2004
Start Page
187
End Page
193
DOI
10.1007/s00066-004-9119-x

A novel conditionally replicative adenovirus vector targeting telomerase-positive tumor cells.

PURPOSE: To develop a novel conditionally replicative adenovirus vector that targets telomerase-positive cancer cells. EXPERIMENTAL DESIGN: A telomerase gene-derived promoter was used to control the expression of the E1a gene so that the E1a gene is only expressed in telomerase-positive tumor cells. In addition, a reporter gene was also engineered into the vector so that its infection and replication can be monitored easily. RESULTS: A novel recombinant adenovirus vector that could selectively replicate in telomerase-positive cancer cells was made successfully. This vector showed active replication in a panel of cancer cells and minimal replication in normal human fibroblast or epithelial cells. The recombinant vector could effectively lyse various cultured tumor cells even at very low multiplicity of infection. The replication efficiency in tumor cells is over 10(3)-fold more than normal fibroblast and epithelial cells. In s.c. tumor models, the newly developed telomerase-selective adenovirus vectors exhibited significantly more virus replication and reporter gene expression. CONCLUSIONS: The telomerase-targeted adenovirus vector has significant potential as an oncolytic virus as well as a tumor-specific therapeutic gene delivery vehicle.

Authors
Huang, Q; Zhang, X; Wang, H; Yan, B; Kirkpatrick, J; Dewhrist, MW; Li, C-Y
MLA Citation
Huang, Q, Zhang, X, Wang, H, Yan, B, Kirkpatrick, J, Dewhrist, MW, and Li, C-Y. "A novel conditionally replicative adenovirus vector targeting telomerase-positive tumor cells." Clin Cancer Res 10.4 (February 15, 2004): 1439-1445.
PMID
14977847
Source
pubmed
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
10
Issue
4
Publish Date
2004
Start Page
1439
End Page
1445

Responses of vascular endothelial cells to angiogenic signaling are important for tumor cell survival.

Neoplastic cells overexpress several angiogenic cytokines, which stimulate neovascularization. Whether the responses of the host endothelial cells to these signaling molecules affect tumor cells during early tumorigenesis has not been investigated. We investigated pre-angiogenic tumor cell survival and angiogenesis initiation by two murine tumor lines (4T1 mammary carcinoma and B16 melanoma), which constitutively expressed GFP, in dorsal skin-fold window chambers of mice treated with extracellular domain of Tie-2 (ExTek) or bFGF. ExTek reduced tumor cell survival, retarded tumor growth, and inhibited angiogenesis onset compared with controls. bFGF increased tumor cell survival and promoted earlier angiogenesis and tumor growth. Neither bFGF nor ExTek affected cell proliferation in vitro. RT-PCR showed mRNA expression of bFGF receptor 2 (FGFR2) IIIb, which does not bind bFGF efficiently, by 4T1 cells and B16 cells express FGFR1 but not FGFR2. B16 cells expressed angiopoietin (Ang) 2, but neither cell line expresses Ang1. Both tumor lines express VEGF. These findings suggested that effects of bFGF and ExTek on tumor cell survival and angiogenesis were not due to direct action but were instead a result of paracrine factors secreted by endothelial cells. These subsequent signals from endothelial cells promote early survival and proliferation of disseminated tumor cells before onset of angiogenesis.

Authors
Shan, S; Robson, ND; Cao, Y; Qiao, T; Li, CY; Kontos, CD; Garcia-Blanco, M; Dewhirst, MW
MLA Citation
Shan, S, Robson, ND, Cao, Y, Qiao, T, Li, CY, Kontos, CD, Garcia-Blanco, M, and Dewhirst, MW. "Responses of vascular endothelial cells to angiogenic signaling are important for tumor cell survival." FASEB J 18.2 (February 2004): 326-328.
PMID
14688196
Source
pubmed
Published In
The FASEB journal : official publication of the Federation of American Societies for Experimental Biology
Volume
18
Issue
2
Publish Date
2004
Start Page
326
End Page
328
DOI
10.1096/fj.03-0765fje

Antitumoral action of interferons and interleukins in combination with radiotherapy. Part II: Radiobiological and immunologic strategies

Background: Combined tumor treatment with cytokines, e.g., interferons (IFN), and radiotherapy was initially of phenomenological nature but has increasingly been based on a radiobiological rationale. However, an improved understanding of the complex interactions of the cytokine network within the immune system warrants the rationale for such studies to be reviewed. Methods: Based on published clinical studies, the results of treatment with interferons in combination with radiotherapy are reviewed. New strategies for antitumoral application of cytokines, illustrated by interleukin-(IL-)2 and IL-12 in preclinical and clinical studies, are presented. Results: The initially high expectations regarding the antitumoral action of IFN-α, IFN-β and IFN-γ in combination with radiotherapy have, with few exceptions, not been fulfilled. In particular, toxicity has been a problem after systemic application. Recent advances in immunology, however, have emphasized the importance of local interactions between antigen-presenting cells and effector cells such as natural killer (NK) cells and cytotoxic T-lymphocytes in the immune reaction against tumors. Preclinical studies with IL-2 und IL-12 have shown efficacy mainly against early metastases, but immune reactions against primary tumors have also been observed. Furthermore, the method and timing of the application have proven to be critical. Conclusion: A few positive clinical studies give cause for hope that a therapeutic benefit may be achieved by targeted, local application of cytokines. Recent preclinical studies indicate the importance of cellular cytokine production in the interaction between the components of the immune system. Gene therapy might contribute to reduce the toxicity associated with cytokine treatment.

Authors
Herskind, C; Fleckenstein, K; Lohr, J; Li, CY; Wenz, F; Lohr, F
MLA Citation
Herskind, C, Fleckenstein, K, Lohr, J, Li, CY, Wenz, F, and Lohr, F. "Antitumoral action of interferons and interleukins in combination with radiotherapy. Part II: Radiobiological and immunologic strategies." Strahlentherapie und Onkologie 180.6 (2004): 331-339.
Source
scival
Published In
Strahlentherapie und Onkologie
Volume
180
Issue
6
Publish Date
2004
Start Page
331
End Page
339
DOI
10.1007/s00066-004-8119-1

Antitumoral Action of Interferons and Interleukins in Combination with Radiotherapy. Part I: Immunologic Basis

Background: During the last 2 decades, cytokines such as interferons (IFN) have been used to modulate tumor response in radiotherapy. Initially, the focus was on antiviral and radiosensitizing effects of interferons but increasingly, the function of interferons and interleukins (IL) within the immune response to tumor cells is becoming important. Method: The cellular immune response toward tumor cells is reviewed. The role of cytokines in antigen presentation and activation of effector cells and their interactions with radiation are described. Preclinical strategies of the antitumor actions of cytokines are presented and discussed based on the induction of IFN-γ by IL-12. Results: Recent advances in immunology have demonstrated the importance of local interactions between antigen-presenting cells (APC) and effector cells such as natural killer (NK) cells and T-lymphocytes for an effective immune reaction against tumors. Interferons stimulate such interactions, while IL-2 plays a central role in the activation of NK cells and T-lymphocytes. The interactions between APC and effector cells are suppressed by many tumors but can be stimulated by irradiation. Since systemic applications of interferons is quite toxic, present strategies aim at local expression, e.g., the induction of IFN-γ expression in Th1 cells by IL-12. Conclusion: The improved understanding of immunologic mechanisms has emphasized the role of the cytokine network in the interaction between tumor cells and effector cells such as NK cells and T-lymphocytes. This opens new possibilities for the application of cytokines as biological response modifiers, which may eventually help widening the therapeutic window in radiotherapy.

Authors
Herskind, C; Fleckenstein, K; Lohr, J; Li, CY; Wenz, F; Lohr, F
MLA Citation
Herskind, C, Fleckenstein, K, Lohr, J, Li, CY, Wenz, F, and Lohr, F. "Antitumoral Action of Interferons and Interleukins in Combination with Radiotherapy. Part I: Immunologic Basis." Strahlentherapie und Onkologie 180.4 (2004): 187-193.
Source
scival
Published In
Strahlentherapie und Onkologie
Volume
180
Issue
4
Publish Date
2004
Start Page
187
End Page
193
DOI
10.1007/s00066-004-9119-x

Systemic virus dissemination during local gene delivery in solid tumors and its control with an alginate solution.

Intratumoral infusion, a routine method for local gene delivery in solid tumors, may cause a systemic dissemination of gene vectors. This is because tumor vessels are intrinsically leaky and intratumoral injection can also result in damage of tumor vessels. To this end, we investigated the extent of virus dissemination during and after local infusion of adenoviral vectors into a murine adenocarcinoma (4T1) transplanted in mice. Three different vectors were used in this study, they contained genes encoding either mouse interleukin-12 (IL-12), luciferase, or enhanced green fluorescence protein (EGFP). The virus distribution in the body was determined as the transgene expression in normal and tumor tissues. Our data demonstrated that a large fraction of injected viral vectors disseminated into liver tissues. To reduce the dissemination problem, we developed a novel method for viral vector delivery based on an alginate solution. We observed that this vehicle could significantly reduce virus dissemination without compromising the therapeutic efficacy of adenoviral vectors. Taken together, the data suggests that systemic virus dissemination is a serious problem in local gene therapy in tumors and that the dissemination can be significantly reduced by an alginate-based polymeric vehicle.

Authors
Wang, Y; Li, C-Y; Yuan, F
MLA Citation
Wang, Y, Li, C-Y, and Yuan, F. "Systemic virus dissemination during local gene delivery in solid tumors and its control with an alginate solution." Conf Proc IEEE Eng Med Biol Soc 5 (2004): 3524-3526.
PMID
17271050
Source
pubmed
Published In
Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
Volume
5
Publish Date
2004
Start Page
3524
End Page
3526
DOI
10.1109/IEMBS.2004.1403991

A phase I hyperthermia-induced interleukin-12 gene-therapy trial in a spontaneously arising feline soft tissue sarcoma model

Authors
Siddiqui, F; Avery, PR; LaRue, SM; Hauck, ML; Dewhirst, MW; Li, C; Ullrich, RL
MLA Citation
Siddiqui, F, Avery, PR, LaRue, SM, Hauck, ML, Dewhirst, MW, Li, C, and Ullrich, RL. "A phase I hyperthermia-induced interleukin-12 gene-therapy trial in a spontaneously arising feline soft tissue sarcoma model." 2004.
Source
wos-lite
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
60
Issue
1
Publish Date
2004
Start Page
S577
End Page
S577

Systemic dissemination of viral vectors during intratumoral injection.

Intratumoral injection is a routine method for local viral gene delivery that may improve interstitial transport of viral vectors in tumor tissues and reduce systemic toxicity. However, the concentration of transgene products in normal organs, such as in the liver, may still exceed normal tissue tolerance if the products are highly toxic. The elevated concentration in normal tissues is likely to be caused by the dissemination of viral vectors from the tumor. Therefore, we investigated transgene expression in the liver, the serum, and a mouse mammary carcinoma (4T1) in mice after intratumoral injection of adenoviral vectors for mouse interleukin-12, luciferase, enhanced green fluorescence protein, or beta-galactosidase. We also performed numerical simulations of virus transport in tumors after intratumoral injection, based on the Krogh cylinder model. Our experimental data and numerical simulations demonstrated that virus dissemination was significant in mice and it occurred mainly during the intratumoral injection. To reduce virus dissemination, we mixed these vectors with a viscous alginate solution and injected the mixture into the tumors. Our data showed that the alginate solution could significantly reduce virus dissemination while having minimal effects on transgene expression in tumors and on interleukin-12-induced tumor growth delay. These data suggest that virus dissemination is a potential problem in local viral gene therapy of cancer and that the dissemination could be significantly reduced by the alginate solution without compromising the efficacy of gene therapy.

Authors
Wang, Y; Hu, JK; Krol, A; Li, Y-P; Li, C-Y; Yuan, F
MLA Citation
Wang, Y, Hu, JK, Krol, A, Li, Y-P, Li, C-Y, and Yuan, F. "Systemic dissemination of viral vectors during intratumoral injection." Mol Cancer Ther 2.11 (November 2003): 1233-1242.
PMID
14617797
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
2
Issue
11
Publish Date
2003
Start Page
1233
End Page
1242

Soluble TGFbeta type II receptor gene therapy ameliorates acute radiation-induced pulmonary injury in rats.

PURPOSE: To assess whether administration of recombinant human adenoviral vector, which carries soluble TGFbeta1 Type II receptor (TbetaRII) gene, might reduce the availability of active TGFbeta1 and thereby protect the lung from radiation-induced injury. METHODS AND MATERIALS: Female Fisher 344 rats were given a single 30 Gy dose of right hemithoracic irradiation 24 h after the injections of control (AdGFP) or treatment (AdexTbetaRII-Fc) vectors. Different end points were assessed to look for lung tissue damage. RESULTS: There was a significant increase in the plasma level of soluble TbetaRII 24 h and 48 h after injection of treatment vector. In the radiation (RT) + AdexTbetaRII-Fc group, there was a significant reduction in respiratory rate at 4 weeks after treatment as compared to the RT-alone group. Histologic results revealed a significant reduction in lung damage and decrease in the number and activity of macrophages in the RT + AdexTbetaRII-Fc group as compared to the RT-alone group. The tissue level of active TGFbeta1 was significantly reduced in rats receiving RT + AdexTbetaRII-Fc treatment. There was also an upregulation of transmembrane TbetaRII in lung tissue in the RT-alone group as compared to the RT + gene therapy rats. CONCLUSIONS: This study shows the ability of AdexTbetaRII-Fc gene therapy to induce an increase in circulating levels of soluble receptors, to reduce the tissue level of active TGFbeta1, and consequently to ameliorate acute radiation-induced lung injury.

Authors
Rabbani, ZN; Anscher, MS; Zhang, X; Chen, L; Samulski, TV; Li, C-Y; Vujaskovic, Z
MLA Citation
Rabbani, ZN, Anscher, MS, Zhang, X, Chen, L, Samulski, TV, Li, C-Y, and Vujaskovic, Z. "Soluble TGFbeta type II receptor gene therapy ameliorates acute radiation-induced pulmonary injury in rats." Int J Radiat Oncol Biol Phys 57.2 (October 1, 2003): 563-572.
PMID
12957270
Source
pubmed
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
57
Issue
2
Publish Date
2003
Start Page
563
End Page
572

Adenovirus dissemination in convention-enhanced delivery and its control with a polymeric vehicle.

Authors
Wang, Y; Li, CY
MLA Citation
Wang, Y, and Li, CY. "Adenovirus dissemination in convention-enhanced delivery and its control with a polymeric vehicle." September 2003.
Source
wos-lite
Published In
ACS National Meeting Book of Abstracts
Volume
226
Publish Date
2003
Start Page
U468
End Page
U468

Increased resistance of tumor cells to hyperthermia mediated by integrin-linked kinase.

PURPOSE: Integrin-linked kinase (ILK) is a serine-threonine kinase associated with anchorage-independent growth and tumorigenic transformation. Previous studies indicate that overexpression of ILK is common among several types of tumors, and it is involved in the regulation of tumor cell survival under stress. In this study, we examined the effects of ILK expression on tumor cellular response to hyperthermia. EXPERIMENTAL DESIGN: We used an adenovirus-mediated approach to overexpress the ILK gene in a prostate cancer cell line and examine its effects on heat stress-induced cell death. Clonogenic survival, as well as apoptosis, was evaluated in cells that overexpress ILK. In addition, the ability to form tumors in vivo was examined in syngeneic hosts. Finally, potential molecular mechanisms of ILK-mediated resistance to heat were examined by determining the status of a variety of signal transduction pathways. RESULTS: ILK overexpression made tumor cells significantly more resistant to the cell-killing effects of hyperthermia. This was correlated at the molecular level with the down-regulation of hyperthermia-induced activation of stress-activated protein kinase/c-Jun-NH(2)-terminal kinase, p38 mitogen-activated protein kinase activities, and caspase 9. The overexpression of ILK was also shown to induce a more rapid tumor growth in a murine prostate cancer cell line CONCLUSION: ILK plays an important role in tumor growth and tumor response to hyperthermia treatment.

Authors
Zhang, X; Li, Y; Huang, Q; Wang, H; Yan, B; Dewhirst, MW; Li, C-Y
MLA Citation
Zhang, X, Li, Y, Huang, Q, Wang, H, Yan, B, Dewhirst, MW, and Li, C-Y. "Increased resistance of tumor cells to hyperthermia mediated by integrin-linked kinase." Clin Cancer Res 9.3 (March 2003): 1155-1160.
PMID
12631621
Source
pubmed
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
9
Issue
3
Publish Date
2003
Start Page
1155
End Page
1160

Role of VEGF in the growth and metastasis of a murine bladder carcinoma

Bladder transitional cell carcinoma is the most common form of carcinoma in the urinary system. Although overexpression of VEGF has been identified in tissue, serum, and urine of patients with bladder cancer, the role of VEGF in transitional cell carcinoma of the bladder has not been clearly elucidated. Here, we dissected the effect of VEGF during bladder tumor growth and progression by modifying a BBN (N-butyl-N-(4-hydroxybutyl) nitrosamine) induced mouse bladder transitional cell carcinoma cell line BTT-T739 by stable transfection of antisense VEGF121 cDNA. The transfection resulted in more than 80% reduction in VEGF production. The growth of the transduced tumor cells in vitro was not affected, however, these cells formed small or no tumors in vivo. Even in the tumors formed, there were minimal vascularization, extensive necrosis and longer latency compared to those formed by parental cells. The permeability of tumor vasculature and metastatic tumor growth were also significantly suppressed in antisense VEGF cDNA transfected cells. In addition, the transfer of anti-angiogenic gene in a combination of sFlk-1 and ExTek with electroporation can suppress the tumor growth efficiently. Taken together, these results demonstrated that VEGF plays an important role in bladder tumor angiogenesis and angiogencsis plays an important role in bladder tumor growth and metastasis.

Authors
Wang, F; Wu, J; Tian, Y; Chen, X; Hu, H; Wu, W; Li, C; Huang, Q
MLA Citation
Wang, F, Wu, J, Tian, Y, Chen, X, Hu, H, Wu, W, Li, C, and Huang, Q. "Role of VEGF in the growth and metastasis of a murine bladder carcinoma." Chinese Science Bulletin 48.22 (2003): 2404-2410.
Source
scival
Published In
Chinese Science Bulletin
Volume
48
Issue
22
Publish Date
2003
Start Page
2404
End Page
2410
DOI
10.1360/03wc0210

GRP94 (gp96) and GRP94 N-terminal geldanamycin binding domain elicit tissue nonrestricted tumor suppression.

In chemical carcinogenesis models, GRP94 (gp96) elicits tumor-specific protective immunity. The tumor specificity of this response is thought to reflect immune responses to GRP94-bound peptide antigens, the cohort of which uniquely identifies the GRP94 tissue of origin. In this study, we examined the apparent tissue restriction of GRP94-elicited protective immunity in a 4T1 mammary carcinoma model. We report that the vaccination of BALB/c mice with irradiated fibroblasts expressing a secretory form of GRP94 markedly suppressed 4T1 tumor growth and metastasis. In addition, vaccination with irradiated cells secreting the GRP94 NH(2)-terminal geldanamycin-binding domain (NTD), a region lacking canonical peptide-binding motifs, yielded a similar suppression of tumor growth and metastatic progression. Conditioned media from cultures of GRP94 or GRP94 NTD-secreting fibroblasts elicited the up-regulation of major histocompatibility complex class II and CD86 in dendritic cell cultures, consistent with a natural adjuvant function for GRP94 and the GRP94 NTD. Based on these findings, we propose that GRP94-elicited tumor suppression can occur independent of the GRP94 tissue of origin and suggest a primary role for GRP4 natural adjuvant function in antitumor immune responses.

Authors
Baker-LePain, JC; Sarzotti, M; Fields, TA; Li, C-Y; Nicchitta, CV
MLA Citation
Baker-LePain, JC, Sarzotti, M, Fields, TA, Li, C-Y, and Nicchitta, CV. "GRP94 (gp96) and GRP94 N-terminal geldanamycin binding domain elicit tissue nonrestricted tumor suppression." J Exp Med 196.11 (December 2, 2002): 1447-1459.
PMID
12461080
Source
pubmed
Published In
The Journal of Experimental Medicine
Volume
196
Issue
11
Publish Date
2002
Start Page
1447
End Page
1459

Hyperthermia-regulated immunogene therapy.

One of the key milestones that must be reached before gene therapy becomes feasible for clinical cancer treatment is to be able to regulate therapeutic gene expression. This is true for most current cancer gene therapy approaches, since the majority of therapeutic genes are toxic to both tumour and normal tissues. Among the wide array of strategies available for regulating gene expression, hyperthermia represents a unique approach. Hyperthermic regulation of gene therapy is feasible because of the widely conserved heat shock response, which allows therapeutic gene expression to be elevated to thousands of fold higher than background when temperature reaches 3-5 degrees C over physiological temperature (37 degrees C). In addition, because of the long history of experimental research on the use of hyperthermia as an approach for cancer therapy, it is now quite feasible to apply hyperthermia to a number of tumour sites and to achieve temperatures that are sufficient to induce a heat shock response. This review will attempt to discuss the current status of hyperthermia-regulated gene therapy, with special emphasis on hyperthermia-regulated immunogene therapy.

Authors
Li, CY; Dewhirst, MW
MLA Citation
Li, CY, and Dewhirst, MW. "Hyperthermia-regulated immunogene therapy." Int J Hyperthermia 18.6 (November 2002): 586-596. (Review)
PMID
12537757
Source
pubmed
Published In
International Journal of Hyperthermia (Informa)
Volume
18
Issue
6
Publish Date
2002
Start Page
586
End Page
596
DOI
10.1080/0265673021000017082

Electromobility of plasmid DNA in tumor tissues during electric field-mediated gene delivery.

Interstitial transport is a crucial step in plasmid DNA-based gene therapy. However, interstitial diffusion of large nucleic acids is prohibitively slow. Therefore, we proposed to facilitate interstitial transport of DNA via pulsed electric fields. To test the feasibility of this approach to gene delivery, we developed an ex vivo technique to quantify the magnitude of DNA movement due to pulsed electric fields in two tumor tissues: B16.F10 (a mouse melanoma) and 4T1 (a mouse mammary carcinoma). When the pulse duration and strength were 50 ms and 233 V/cm, respectively, we found that the average plasmid DNA movements per 10 pulses were 1.47 microm and 0.35 microm in B16.F10 and 4T1 tumors, respectively. The average plasmid DNA movements could be approximately tripled, ie to reach 3.69 microm and 1.01 microm, respectively, when the pulse strength was increased to 465 V/cm. The plasmid DNA mobility was correlated with the tumor collagen content, which was approximately eight times greater in 4T1 than in B16.F10 tumors. These data suggest that electric field can be a powerful driving force for improving interstitial transport of DNA during gene delivery.

Authors
Zaharoff, DA; Barr, RC; Li, C-Y; Yuan, F
MLA Citation
Zaharoff, DA, Barr, RC, Li, C-Y, and Yuan, F. "Electromobility of plasmid DNA in tumor tissues during electric field-mediated gene delivery." Gene Ther 9.19 (October 2002): 1286-1290.
PMID
12224011
Source
pubmed
Published In
Gene Therapy
Volume
9
Issue
19
Publish Date
2002
Start Page
1286
End Page
1290
DOI
10.1038/sj.gt.3301799

Intravital fluorescence facilitates measurement of multiple physiologic functions and gene expression in tumors of live animals.

The purpose of this report is to present an overview of the use of fluorescence imaging in vivo, with particular emphasis on oncology. It is important to note, however, that many of the methods described herein have been applied to the study of non-malignant tissues as well. Modern medicine and biology research has benefited greatly from an ever-expanding assortment of fluorescent markers and labels. These markers and labels have allowed investigators to observe the behavior and properties of cell and molecular entities of interest in the context of complicated biological systems such as a mammalian cell or a whole mouse. Methods developed to image fluorescence in whole mice have been valuable in studying patterns of tumor growth and metastases. Alternatively, more detailed information and a wide variety of endpoints can be obtained using "intravital" preparations. This review focuses on use of fluorescence imaging for intravital preparations. For detail on fluorescence imaging of whole animals, refer to reviews on this subject [1,2]. For oncologic applications, studies have focused primarily on window chamber preparations that allow for real-time visualization of tumor growth, vascularity, vascular responses to stimulation, vascular permeability, vascular orientation, flow instability, and the like. These endpoints have been used to show that there are functional differences between tumor and normal tissues with respect to these functions under baseline conditions and after therapeutic manipulation. Examples of some of these differences are provided in this review as a means to illustrate how they can be used.

Authors
Dewhirst, MW; Shan, S; Cao, Y; Moeller, B; Yuan, F; Li, C-Y
MLA Citation
Dewhirst, MW, Shan, S, Cao, Y, Moeller, B, Yuan, F, and Li, C-Y. "Intravital fluorescence facilitates measurement of multiple physiologic functions and gene expression in tumors of live animals." Dis Markers 18.5-6 (2002): 293-311. (Review)
PMID
14646042
Source
pubmed
Published In
Disease markers
Volume
18
Issue
5-6
Publish Date
2002
Start Page
293
End Page
311

Target gene transfer mediated by electroporation for cancer therapy in vivo

A plasmid encoding green florescent protein (GFP) was first used to test efficiency of electroporation and optimize parameters for electroporation in vivo. GFP plasmid was efficiently delivered into muscle by electroporation and robust GFP expression in muscle could be observed more than three weeks. While much less GFP positive cells were observed in tumor and GFP expression could only last 6 days but tumors treated with high voltage/short pulse showed about 2.68 fold more GFP positive cells than tumors treated with low voltage/long pulses. The optimized electroporation parameters was used to mediate therapeutic gene transfer into subcutaneous tumors which derived from T739 mice bladder transitional cell carcinoma cell line (BTT-gfp), human mammary carcinoma cell line (MCF-7) and human hepatoma cell line (SMMC 7721-gfp). Those therapeutic genes included immune reaction regulation factors interleukin12, interleukin2 and GM-CSF or anti-angiogenesis factors such as antisense VEGF121cDNA, soluble form of VEGF receptor (sFlk-1) and Tie2 (ExTek). Inhibition of tumor growth and metastasis were observed in T739 mice carried bladder transitional cell carcinoma and nude mice carried either human breast cancer or liver cancer which were treated with multiple transfers of plasmid encoding interleukine12 mediated by electroporation. MCF-7 and SMMC 7721-gfp derived tumor showed sensitive to single anti-angiogenesis gene therapy, yet definite suppression of growth and metastasis of BTT-gfp tumor was resulted from co-tranfer of sFlk-1 and ExTek gene mediated by electroporation. The results suggest that electroporation is a high efficient, safe and economical method for gene transfer in vivo and electro-gene therapy would be a useful method for solid tumor.

Authors
Wang, F; Chen, X-F; Tian, Y-H; Wu, J-H; Li, L; Li, C-Y; Huang, Q
MLA Citation
Wang, F, Chen, X-F, Tian, Y-H, Wu, J-H, Li, L, Li, C-Y, and Huang, Q. "Target gene transfer mediated by electroporation for cancer therapy in vivo." Progress in Biochemistry and Biophysics 29.5 (2002): 734-740.
Source
scival
Published In
Progress in Biochemistry and Biophysics
Volume
29
Issue
5
Publish Date
2002
Start Page
734
End Page
740

Inhibitation of tumor angiogenesis, growth and metastasis by blocking VEGF paracrine pathway

Solid tumors require an adequate vascular supply to grow beyond a certain dimension. It is known that formation of new blood vessels in tumor is mediated by unbalanced expression of angiogenic factors and their inhibitors. Among the former, the vascular endothelial growth factor (VEGF) has been assumed prime candidacy as a major positive physiological effector. To investigate the role of VEGF in angiogenesis associated with development of breast cancer, a sense VEGF and an anti-sense VEGF expression plasmids were constructed, and then were introduced into a human breast carcinoma cell line, MCF-7, expressing middle level of endogenous VEGF. Anti-sense VEGF121 transfected MCF-7 cells that expressed reduced constitutive levels of VEGF and showed the same growing potential as untransfected MCF-7 cells in vitro, but it showed longer latency, smaller tumor, slower growth and prolonged survival time compared to parental or sense VEGF165 transfected MCF-7 cells in vivo. Moreover, the tumors derived from anti-sense VEGF121 transfected MCF-7 cells characterized by minimal vascularization and extensive necrosis. Finally, mice with primary subcutaneous tumors treated with intratumoral administration of anti-sense VEGF, or the plasmid expressing extracellular domain of the Flk-1 VEGF receptor (sFlk-1) followed by electroporation, showed significant tumor suppression. These results suggest that VEGF plays a major angiogenic role in breast cancer and a strategy, which blocks the VEGF paracrine pathway, may provide a means to control tumor growth topically without the risk of systemic antiangiogenesis.

Authors
Wang, F; Tian, Y-H; Li, L; Chen, X-F; Hu, H-H; Li, C-Y; Huang, Q
MLA Citation
Wang, F, Tian, Y-H, Li, L, Chen, X-F, Hu, H-H, Li, C-Y, and Huang, Q. "Inhibitation of tumor angiogenesis, growth and metastasis by blocking VEGF paracrine pathway." Acta Biochimica et Biophysica Sinica 34.2 (2002): 165-170.
PMID
12006990
Source
scival
Published In
Acta Biochimica et Biophysica Sinica
Volume
34
Issue
2
Publish Date
2002
Start Page
165
End Page
170

Cell cycle deregulation and xeroderma pigmentosum group C cell transformation

We previously described a genetically unstable human fibroblast cell strain (GM2995), isolated from normal appearing skin of a xeroderma pigmentosum group C patient that repeatedly underwent changes characteristic of the transformed phenotype upon serial cultivation in vitro. In order to gain information concerning genetic changes associated with the transformation of this xeroderma pigmentosum group C cell strain, we examined the expression/function of several cell cycle regulators during its serial cultivation. A mutation in exon 8 of the P53 gene was associated with loss of function of the p53 protein and appeared at about the same time that transformation occurred. Abnormal P53 function was confirmed by the lack of upregulation of p53 as well as activation of its downstream effectors p21Waf1 and HDM2 in high passage cells exposed to either c irradiation or ultraviolet C irradiation. Consistent with deregulation in cell cycle control, persistent hyperphosphorylation of the retinoblastoma protein and lack of a decrease in p34cdc2 were observed in irradiated cells. Furthermore, retinoblastoma protein remained hyperphosphorylated in control high passage confluent cultures that were serum starved for 72 h. Compared with low passage cells, the expression levels of the cyclin-dependent kinase inhibitor p27Kip1 were significantly reduced and the pattern of expression of the von Hippel-Lindau protein was aberrant. These data indicate that the process of cellular transformation of this xeroderma pigmentosum group C cell strain involves the progressive acquisition of mutations and abnormalities in the expression/function of several cell cycle regulators.

Authors
Azzam, EI; Nagasawa, H; Yu, Y; Li, C-Y; Little, JB
MLA Citation
Azzam, EI, Nagasawa, H, Yu, Y, Li, C-Y, and Little, JB. "Cell cycle deregulation and xeroderma pigmentosum group C cell transformation." Journal of Investigative Dermatology 119.6 (2002): 1350-1354.
PMID
12485438
Source
scival
Published In
Journal of Investigative Dermatology
Volume
119
Issue
6
Publish Date
2002
Start Page
1350
End Page
1354
DOI
10.1046/j.1523-1747.2002.19628.x

Reducing systemic toxicity in local tumor gene therapy using an alginate solution

To reduce dissemination of viral vectors and their gene products during and after local gene therapy, we mixed adenoviral vectors with an alginate solution and subsequently injected the mixture into mouse tumors. We found that the alginate solution significantly reduced the dissemination of adenoviral vectors for EGFP and IL-12 into the liver and the IL-12 concentration in the serum. On the other hand, the alginate solution had no effects on EGFP and IL-12 expressions in tumors as well as the growth of IL-12 vector treated tumors.

Authors
Wang, Y; Hu, JK; Krol, A; Li, Y-P; Li, C-Y; Yuan, F
MLA Citation
Wang, Y, Hu, JK, Krol, A, Li, Y-P, Li, C-Y, and Yuan, F. "Reducing systemic toxicity in local tumor gene therapy using an alginate solution." Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings 1 (2002): 565--.
Source
scival
Published In
Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
Volume
1
Publish Date
2002
Start Page
565-

A novel model for visualization of tumor cell-induced angiogenesis in vivo

The bladder transitional cell carcinoma cell line, BTT739 from the T739 mouse, was transfected with a plasmid that encoded an enhanced green fluorescence protein (GFP) and the cells stably expressing GFP were selected and subcloned. 1 × 103-1 × 104 GFP-labeled BTT739 cells were injected under the skin of ear of T739 mice. On day 2-5 post injection, the most interesting manifestations observed were the chemotaxis-like movement of the tumor cells toward the pre-existing host vasculature, host vessel dilation and tortuosity and increased extravasation. On day 10 or later, the sprout from pre-existing host vasculature was observed. Once angiogenesis was triggered on, the tumor cells grew more rapidly and exhibited a specific growth pattern where tumor cells always associated with or surrounded the vessels. The newly formed microvessels always showed heavy extravasation. Immunohistochemistry staining revealed strong VEGF and VEGFR2 (Flk-1) expression in tumor cells. Angiography using Rhodamin-labeled dextran showed neovascularization with unprecedented clarity. However, the tumor mass, even bigger than 2 mm and being neovascularized, shrunk and then disappear in 3-5 days and left only delicated host vessels and recovered extravasation. The evidence from this observation indicated that angiogenesis induced by tumor cells after implantation into the host begins at very early stage. The micrometastases foci could not form or survive without vigorous and continuous angiogenesis. Furthermore, there was active VEGF paracrine and autocrine expression in tumor and high level VEGF secretion by tumor cells plays an important role in initiating angiogenesis and supporting micrometastases.

Authors
Li, L; Xu, P; Hu, H-H; Liu, W-W; Yi, M-Y; Li, C-Y; Huang, Q
MLA Citation
Li, L, Xu, P, Hu, H-H, Liu, W-W, Yi, M-Y, Li, C-Y, and Huang, Q. "A novel model for visualization of tumor cell-induced angiogenesis in vivo." Acta Biochimica et Biophysica Sinica 34.1 (2002): 21-27.
PMID
11958129
Source
scival
Published In
Acta Biochimica et Biophysica Sinica
Volume
34
Issue
1
Publish Date
2002
Start Page
21
End Page
27

Protection against oxidized low-density lipoprotein-induced vascular endothelial cell death by integrin-linked kinase.

BACKGROUND: Integrin-linked kinase (ILK) is a protein that plays important roles in extracellular matrix-mediated signaling. It has been shown that ILK is expressed preferentially in cardiac and skeletal muscles. Evidence points to its role as an upstream regulator of protein kinase B, a critical player in apoptosis. Because oxidized LDL (oxLDL) is thought to promote atherogenesis by causing the apoptosis of endothelial cells, we investigated the potential roles that ILK may play in oxLDL-induced apoptosis in vascular endothelial cells. METHODS AND RESULTS: Transcriptional and translational levels of ILK were investigated with reverse-transcriptase polymerase chain reaction and Western analysis. oxLDL treatment induced both the transcription and the translation of the ILK gene in endothelial cells. A recombinant adenovirus vector encoding the ILK gene was constructed to investigate its potential role in oxLDL-induced apoptosis in human umbilical vein endothelial cells and mouse lymphoid vein endothelial cells transformed by simian virus 40. In both types of cells, overexpression of the ILK gene significantly prevented oxLDL-induced apoptosis or cell death, as evaluated by 2 independent assay methods. Furthermore, we showed that ILK could inhibit oxLDL-induced upregulation of the kinase activity of p38 mitogen-activated protein kinase, which is often associated with stress-induced pro-apoptotic signal transduction. Finally, examination of other factors, such as bcl-2, bcl-xl, caspase 3, and caspase 9, demonstrated significant changes that were correlated with oxLDL treatment and ILK overexpression. CONCLUSIONS: ILK may be an important factor involved in the regulation of oxLDL-induced apoptosis in vascular endothelial cells. Modifying its activity may be a useful approach for prevention of endothelial cell injury in oxLDL-induced atherosclerosis.

Authors
Zhang, X; Hu, K; Li, CY
MLA Citation
Zhang, X, Hu, K, and Li, CY. "Protection against oxidized low-density lipoprotein-induced vascular endothelial cell death by integrin-linked kinase." Circulation 104.23 (December 4, 2001): 2762-2766.
PMID
11733391
Source
pubmed
Published In
Circulation
Volume
104
Issue
23
Publish Date
2001
Start Page
2762
End Page
2766

Systemic vector leakage and transgene expression by intratumorally injected recombinant adenovirus vectors.

Interleukin 12 is a heterodimeric cytokine that exhibits potent immunostimulatory effects. It has shown some promise in preclinical and clinical studies but was accompanied by serious systemic toxicity such as flu-like syndromes, a rapid transient leukopenia, elevated liver transaminases, gastrointestinal toxicity, and/or liver dysfunction. Gene therapy with intratumorally injected recombinant adenoviral vectors offers the potential to restrict therapeutic gene expression in the tumor. Here we show that a substantial amount of adenoviral vectors disseminates into the systemic circulation and infects parenchymal organs. We further show that this results in high systemic levels of potentially toxic transgene products. To reduce potential toxicity, we tested an inducible promoter based on the heat shock proteins (hsp70B) and present evidence that high intratumoral levels of a therapeutic transgene can be obtained while systemic expression is reduced to a minimum, increasing the safety of adenovirus-based tumor gene therapy.

Authors
Lohr, F; Huang, Q; Hu, K; Dewhirst, MW; Li, CY
MLA Citation
Lohr, F, Huang, Q, Hu, K, Dewhirst, MW, and Li, CY. "Systemic vector leakage and transgene expression by intratumorally injected recombinant adenovirus vectors." Clin Cancer Res 7.11 (November 2001): 3625-3628.
PMID
11705885
Source
pubmed
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
7
Issue
11
Publish Date
2001
Start Page
3625
End Page
3628

Effects of soluble Tie-2 receptor and bFGF on GFP-4T1 tumor growth and initiation of angiogenesis in BALB/C mouse dorsal skinfold window chamber.

Authors
Shan, S; Hu, K; Saito, W; Li, C; Dewhirst, MW
MLA Citation
Shan, S, Hu, K, Saito, W, Li, C, and Dewhirst, MW. "Effects of soluble Tie-2 receptor and bFGF on GFP-4T1 tumor growth and initiation of angiogenesis in BALB/C mouse dorsal skinfold window chamber." CLINICAL CANCER RESEARCH 7.11 (November 2001): 3658S-3658S.
Source
wos-lite
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
7
Issue
11
Publish Date
2001
Start Page
3658S
End Page
3658S

Generation of recombinant adeno-associated virus vectors by a complete adenovirus-mediated approach.

An efficient approach to the large-scale production of rAAV will significantly facilitate the application of this promising gene delivery vector in human gene therapy applications. In this study, we report a novel approach to rAAV production that is based exclusively on the adenovirus vector, without the need for plasmid transfections and special packaging cell lines. All components required for rAAV production, including the rep and cap genes, and the therapeutic gene(s) are delivered to the widely used 293 packaging cell line by adenovirus vectors. High-titer rAAV vectors (200-600 infectious units/producer cell) were obtained by use of this approach. As adenovirus vectors can be produced to high titers and they can infect cells in suspension efficiently, this approach may be amenable to scaled-up production of rAAV vectors.

Authors
Zhang, X; Li, CY
MLA Citation
Zhang, X, and Li, CY. "Generation of recombinant adeno-associated virus vectors by a complete adenovirus-mediated approach." Mol Ther 3.5 Pt 1 (May 2001): 787-792.
PMID
11356083
Source
pubmed
Published In
Molecular Therapy
Volume
3
Issue
5 Pt 1
Publish Date
2001
Start Page
787
End Page
792
DOI
10.1006/mthe.2001.0306

Effective tumor therapy with plasmid-encoded cytokines combined with in vivo electroporation.

Plasmids may have unique advantages as a gene delivery system. However, a major obstacle is the low in vivo transduction efficiency. In this study, an electroporation-based gene transduction approach was taken to study the effect of interleukin (IL)-2 or IL-12 gene transduction on the growth of experimental murine tumors. Significant intratumoral gene transduction was achieved by electroporation of tumors that had been injected with naked plasmids encoding reporter genes and cytokine genes (IL-2 and IL-12) under the control of a constitutive cytomegalovirus promoter. In addition, significant tumor growth delay could be achieved in a murine melanoma line B16.F10 with the cytokine genes. Most importantly, systemic transgene levels were negligible when compared with intratumoral adenovirus-mediated IL-12 gene delivery, which leads to significantly higher systemic cytokine levels. Therefore, naked plasmid- and in vivo electroporation-mediated cancer gene therapy may be therapeutically efficacious while maintaining low systemic toxicity.

Authors
Lohr, F; Lo, DY; Zaharoff, DA; Hu, K; Zhang, X; Li, Y; Zhao, Y; Dewhirst, MW; Yuan, F; Li, CY
MLA Citation
Lohr, F, Lo, DY, Zaharoff, DA, Hu, K, Zhang, X, Li, Y, Zhao, Y, Dewhirst, MW, Yuan, F, and Li, CY. "Effective tumor therapy with plasmid-encoded cytokines combined with in vivo electroporation." Cancer Res 61.8 (April 15, 2001): 3281-3284.
PMID
11309280
Source
pubmed
Published In
Cancer Research
Volume
61
Issue
8
Publish Date
2001
Start Page
3281
End Page
3284

Persistent genetic instability in cancer cells induced by non-DNA-damaging stress exposures.

A hallmark of cancer cells is their pronounced genetic instability, which has been implicated in both tumor development and negative treatment outcomes. Recently, it has been reported that ionizing radiation may induce a persistent state of hypermutability in mammalian cells that lasts for many (>30) cell divisions. In this study, we examined whether other stress signals (both DNA-damaging non-DNA-damaging) can initiate a similar process. We show that persistent genetic instability was induced by nongenotoxic stress exposures such as heat treatment, serum starvation, or the tumor microenvironment, as well as genotoxic stresses such as ionizing radiation and exposure to hydrogen peroxide. Progeny of 10-20% of surviving cells exhibited persistent and pronounced genetic instability at both an artificially transfected gene and a genomic minisatellite locus 23 cell divisions after the initial exposure. Stress-induced persistent genetic instability may be a general response of tumor cells to a wide range of genotoxic or nongenotoxic stress conditions.

Authors
Li, CY; Little, JB; Hu, K; Zhang, W; Zhang, L; Dewhirst, MW; Huang, Q
MLA Citation
Li, CY, Little, JB, Hu, K, Zhang, W, Zhang, L, Dewhirst, MW, and Huang, Q. "Persistent genetic instability in cancer cells induced by non-DNA-damaging stress exposures." Cancer Res 61.2 (January 15, 2001): 428-432.
PMID
11212225
Source
pubmed
Published In
Cancer Research
Volume
61
Issue
2
Publish Date
2001
Start Page
428
End Page
432

Preparation of green fluorescent protein retrovirus and its application in mediating gene transfer into retinal pigment epithelial cells

OBJECTIVE: To determine whether human retinal pigment epithelial (RPE) cells can be infected by retrovirus and modified by retrovirus-mediated gene transfer. METHODS: Recombination retroviral vector pLNCX-GFP (green fluorescent protein, GFP) was generated by inserting 780 bp GFP cDNA fragment into the MCS site of pLNCX. pLNCX-GFP was transfected into ecotropic packaging cell line PhiX-Eco and amphotropic packaging cell line PhiX-Ampho and PA317. Retroviral titer was tested by counting GFP expression of NIH3T3 cells. Then RPE cells were infected by using GFP retrovirus-containing supernatant. RESULTS: GFP was expressed and retrovirus was produced upon pLNCX-GFP being transfected into packaging cell line. The GFP retrovirus was able to infect primary cultured human RPE cells and immortalized RPE cell line. CONCLUSION: The retrovirus can introduce a foreign gene into RPE cells efficiently, thereby it can be used as an important tool to deliver gene into RPE for therapy of fundus diseases.

Authors
Huang, Q; Xu, P; Liu, W; Wang, F; Gu, Q; Tian, S; Fan, Y; Xig, K; Chen, X; Li, C
MLA Citation
Huang, Q, Xu, P, Liu, W, Wang, F, Gu, Q, Tian, S, Fan, Y, Xig, K, Chen, X, and Li, C. "Preparation of green fluorescent protein retrovirus and its application in mediating gene transfer into retinal pigment epithelial cells." [Zhonghua yan ke za zhi] Chinese journal of ophthalmology 37.4 (2001): 248-251.
PMID
11864429
Source
scival
Published In
[Zhonghua yan ke za zhi] Chinese journal of ophthalmology
Volume
37
Issue
4
Publish Date
2001
Start Page
248
End Page
251

Using Hsp70 promoter to regulate target gene expression in tumor

OBJECTIVE: To regulate gene expression in the desired tumor cells both in vitro and in vivo. METHODS: Heat inducible green fluorescent protein (GFP) expression plasmid and adenovirus were built by using different sizes of 5' end regulating sequence from human heat shock protein (Hsp) gene as promoter and GFP cDNA as report gene. GFP expression turned on by heating was observed in the cultured cells and the tumor grown in the dorsal skin window chamber. RESULTS: A 400 bp of Hsp gene 5' end regulating sequence can be activated by heating and it can drive report gene expression effectively both in vitro and in vivo. CONCLUSIONS: Heating can selectively induce gene expression in the targeted tumor. It provides an useful tool for cancer gene therapy because it possibly maximizes tumor cell killing and minimizes normal tissue damage.

Authors
Huang, Q; Li, C
MLA Citation
Huang, Q, and Li, C. "Using Hsp70 promoter to regulate target gene expression in tumor." Zhonghua bing li xue za zhi Chinese journal of pathology 30.3 (2001): 198-201.
PMID
11866978
Source
scival
Published In
Zhonghua bing li xue za zhi Chinese journal of pathology
Volume
30
Issue
3
Publish Date
2001
Start Page
198
End Page
201

Control of gene therapy by the heat shock promoter

Authors
Li, CY; Dewhirst, MW
MLA Citation
Li, CY, and Dewhirst, MW. "Control of gene therapy by the heat shock promoter." 2001.
Source
wos-lite
Published In
PROGRESS IN RADIO-ONCOLOGY VII, PROCEEDINGS
Publish Date
2001
Start Page
577
End Page
586

Enhancement of radiotherapy by hyperthermia-regulated gene therapy.

PURPOSE: Interleukin 12 (IL-12) has shown strong antitumoral effects in numerous pre-clinical studies and appears to act synergistically with radiation in murine tumors. The major impediment to its clinical use has been its systemic toxicity. While using intratumorally injected viral gene therapy vectors encoding IL-12 reduces systemic side effects substantially, elevated systemic transgene levels are still observed because adenovirus can reach the circulation. Further restricting IL-12 expression in the tumor is therefore desirable in a combined radiation and adenovirus mediated cancer gene therapy regimen. METHODS AND MATERILAS: Hyperthermia-regulated gene therapy was tested in a nonimmunogenic B16.F10 melanoma line that is syngeneic with C57BL/6 mice. For hyperthermic gene therapy, an adenoviral vector coding for IL-12 under the control of the promoter of the human heat shock protein 70B (hsp70B) was used. One week after transplantation (at a 5-7 mm diameter), tumors were irradiated with 3 x 11 Gy (mo-we-fri). Adenovirus was injected at 3 x 10(8) pfu/tumor 24 h before the last radiation fraction or 3 days afterwards. Hyperthermia was performed 24 h later at 42.5 degrees C. Growth delay to reaching 3 times initial tumor volume was chosen as the biologic endpoint. IL-12 levels in tumor and serum were determined by using the enzyme-linked immunosorbant assay (ELISA). RESULTS: Adenovirus mediated intratumoral expression of IL-12 under the control of a heat inducible promoter in combination with hyperthermia is almost as effective as that under the control of a constitutive cytomegaly virus (CMV) promoter while systemic transgene levels are substantially reduced with the heat inducible promoter. The response to radiotherapy is improved considerably when combined with heat inducible gene therapy without apparent systemic toxicity. When used as a single dose, applying IL-12 gene therapy after completion of radiotherapy appears to be beneficial. CONCLUSIONS: Hyperthermia-regulated gene therapy in combination with radiation is feasible and therapeutically effective in murine tumors with no apparent systemic toxicity.

Authors
Lohr, F; Hu, K; Huang, Q; Zhang, L; Samulski, TV; Dewhirst, MW; Li, CY
MLA Citation
Lohr, F, Hu, K, Huang, Q, Zhang, L, Samulski, TV, Dewhirst, MW, and Li, CY. "Enhancement of radiotherapy by hyperthermia-regulated gene therapy." Int J Radiat Oncol Biol Phys 48.5 (December 1, 2000): 1513-1518.
PMID
11121657
Source
pubmed
Published In
International Journal of Radiation Oncology, Biology, Physics
Volume
48
Issue
5
Publish Date
2000
Start Page
1513
End Page
1518

RESPONSE: re: initial stages of tumor cell-induced angiogenesis: evaluation via skin window chambers in rodent models

Authors
Li, CY; Shan, S; Huang, Q; Dewhirst, MW
MLA Citation
Li, CY, Shan, S, Huang, Q, and Dewhirst, MW. "RESPONSE: re: initial stages of tumor cell-induced angiogenesis: evaluation via skin window chambers in rodent models." J Natl Cancer Inst 92.17 (September 6, 2000): 1445-1446.
PMID
10974088
Source
pubmed
Published In
Journal of the National Cancer Institute
Volume
92
Issue
17
Publish Date
2000
Start Page
1445
End Page
1446

Combination treatment of murine tumors by adenovirus-mediated local B7/IL12 immunotherapy and radiotherapy.

Failure of local tumor control still poses a problem for radiotherapy and translates into reduced survival. Combining radiation with chemotherapy or other newer modalities has shown promising results. Immunological approaches to tumor therapy have found renewed interest due to improved insight into mechanisms involved in the immune response to tumors. In this paper, we studied tumor growth delay after various combination regimens of locally injected adenovirus constitutively expressing IL12 and B7.1 (AdIL12/B7.1) and fractionated radiotherapy in two nonimmunogenic murine tumor models, 4T1 and B16.F10. Effects of radiation and virus infection on surface antigen expression in these tumor lines were assessed. Mechanisms of action of AdIL12/B7.1 were studied by conducting additional experiments with and without depletion of NK-cells and/or T-cells, and by cytotoxic T-lymphocyte assays, and immunohistochemical evaluation of tumor blood vessels. Both B7.1 and IL12 were effectively expressed in both irradiated and unirradiated 4T1 and B16.F10 tumor cells but did not add significantly to radiation-induced cell killing in vitro. However, local tumor infection by AdIL12/B7.1 after irradiation significantly increases the effectiveness of radiotherapy when applied after completion of radiotherapy. The mechanism appears to be complicated, involving a host of factors that included the ability of IL12 to activate T-cells and NK-cells and to inhibit angiogenesis and the ability of radiation to induce apoptosis or necrosis among tumor cells. These data support the combination of radiotherapy with adenovirus-mediated immunotherapy and suggest that the concept of adding genetic immunotherapy after radiotherapy in a combined regimen merits further study.

Authors
Lohr, F; Hu, K; Haroon, Z; Samulski, TV; Huang, Q; Beaty, J; Dewhirst, MW; Li, CY
MLA Citation
Lohr, F, Hu, K, Haroon, Z, Samulski, TV, Huang, Q, Beaty, J, Dewhirst, MW, and Li, CY. "Combination treatment of murine tumors by adenovirus-mediated local B7/IL12 immunotherapy and radiotherapy." Mol Ther 2.3 (September 2000): 195-203.
PMID
10985949
Source
pubmed
Published In
Molecular Therapy
Volume
2
Issue
3
Publish Date
2000
Start Page
195
End Page
203
DOI
10.1006/mthe.2000.0114

Heat-induced gene expression as a novel targeted cancer gene therapy strategy.

One of the main advantages of gene therapy over traditional therapy is the potential to target the expression of therapeutic genes in desired cells or tissues. To achieve targeted gene expression, we experimented with a new approach based on the long-established phenomenon of the heat shock response. By using the green fluorescence protein as a reporter gene, it was demonstrated that expression of a heterologous gene with a heat shock protein 70 promoter could be elevated to 500-1000-fold over background by moderate hyperthermia (39 degrees C to 43 degrees C) in tissue cultured cells. The heat-induced green fluorescence protein expression was first detectable at 3 h after heating and reached a maximum at 18-24 h. The expression dropped back to baseline within 72 h. In addition, when cells were infected with adenovirus vectors containing the heat-inducible interleukin 12 or tumor necrosis factor alpha genes and then heated (42 degrees C, 30 min), expression was at least 13,600- or 6.8 x 10(5)-fold over background, respectively. Intralesion injection of the interleukin-12-carrying adenovirus vector in a mouse melanoma tumor model caused significant tumor growth delay only with hyperthermia treatment. Our results therefore support heat-induced gene expression as a feasible approach for targeted cancer gene therapy.

Authors
Huang, Q; Hu, JK; Lohr, F; Zhang, L; Braun, R; Lanzen, J; Little, JB; Dewhirst, MW; Li, CY
MLA Citation
Huang, Q, Hu, JK, Lohr, F, Zhang, L, Braun, R, Lanzen, J, Little, JB, Dewhirst, MW, and Li, CY. "Heat-induced gene expression as a novel targeted cancer gene therapy strategy." Cancer Res 60.13 (July 1, 2000): 3435-3439.
PMID
10910053
Source
pubmed
Published In
Cancer Research
Volume
60
Issue
13
Publish Date
2000
Start Page
3435
End Page
3439

Initial stages of tumor cell-induced angiogenesis: evaluation via skin window chambers in rodent models.

BACKGROUND: There is a paucity of information about events that follow immediately after tumor cells are triggered to initiate the process of angiogenesis (the formation of new blood vessels). Such information is relevant to the issue of when micrometastases vascularize and has implications for the accessibility of micrometastases to various treatments. In this study, we attempted to monitor events at the initiation of angiogenesis at the earliest possible stage of tumor growth in vivo. METHODS: Two different rodent mammary tumor cell lines, R3230Ac from the Fischer 344 rat and 4T1 from the BALB/c mouse, were stably transfected with a gene that encodes an enhanced version of green fluorescence protein (GFP). GFP-labeled R3230Ac or 4T1 cells (about 20-50 cells) were implanted into dorsal skinfold window chambers of Fischer 344 rats or BALB/c mice, respectively. Tumor angiogenesis was then monitored serially and noninvasively for up to 4 weeks. RESULTS: Clear evidence of modification of the host vasculature was observed when tumor mass reached approximately 60-80 cells, and functional new blood vessels were seen when tumor mass reached roughly 100-300 cells. Individual tumor cells exhibited a chemotaxis-like growth pattern toward the pre-existing host vasculature. When ex-flk1 (a soluble, truncated vascular endothelial cell growth factor receptor protein known to be antiangiogenic) was injected with the tumor cells, the initial angiogenic and tumor growth activities were inhibited considerably, indicating that angiogenesis inhibitors may halt tumor growth even before the onset of angiogenesis. CONCLUSION: Angiogenesis induced by tumor cells after implantation in the host begins at a very early stage, i.e., when the tumor mass contains roughly 100-300 cells. Identification of chemotactic signals that initiate tumor cell migration toward the existing vasculature may provide valuable targets for preventing tumor progression and/or metastases.

Authors
Li, CY; Shan, S; Huang, Q; Braun, RD; Lanzen, J; Hu, K; Lin, P; Dewhirst, MW
MLA Citation
Li, CY, Shan, S, Huang, Q, Braun, RD, Lanzen, J, Hu, K, Lin, P, and Dewhirst, MW. "Initial stages of tumor cell-induced angiogenesis: evaluation via skin window chambers in rodent models." J Natl Cancer Inst 92.2 (January 19, 2000): 143-147.
PMID
10639516
Source
pubmed
Published In
Journal of the National Cancer Institute
Volume
92
Issue
2
Publish Date
2000
Start Page
143
End Page
147

Role of incipient angiogenesis in cancer metastasis.

Metastasis is the primary cause of mortality in cancer patients. Angiogenesis is intimately involved in metastasis at the site of entry of tumor cells into the vasculature and at the site of eventual metastasis growth. In this commentary, we review current paradigms regarding angiogenesis in metastatic sites. Recent discoveries challenge some of the existing paradigms. Significant prior data suggest that successful formation of metastases requires: 1) angiogenesis in the primary tumor site; 2) downregulation of cohesive molecules and tumor cell increased motility, resulting in invasion into neovessels; 3) tumor cell embolism; 4) arrest and attachment in capillary beds of distant organs; 5) extravasation and proliferation in the organ parenchyma; and 6) re-establishment of angiogenesis when the tumor reaches > 1-2 mm in size [1]. While most recent data largely confirm the aforementioned sequence of events, a few reports have revealed new knowledge about the earliest phases of angiogenesis of metastases. Of particular importance has been the ability to create tumor cell lines that are stably transfected with reporter genes, such as green fluorescence protein. With these tools it is now literally possible to monitor tumor formation from a single cell [2-7].

Authors
Li, CY; Shan, S; Cao, Y; Dewhirst, MW
MLA Citation
Li, CY, Shan, S, Cao, Y, and Dewhirst, MW. "Role of incipient angiogenesis in cancer metastasis." Cancer Metastasis Rev 19.1-2 (2000): 7-11. (Review)
PMID
11191066
Source
pubmed
Published In
Cancer and Metastasis Reviews
Volume
19
Issue
1-2
Publish Date
2000
Start Page
7
End Page
11

Mobility of plasmid DNA subject to pulsed electric fields

The mobility of plasmid DNA in high amplitude/low duration electric fields was assessed. The influences of pulse amplitude, pulse duration and agarose gel concentration on mobility were compared. Movement of plasmid DNA in an electroporation setting was increased over diffusion one to two orders of magnitude, depending on pulse duration and frequency.

Authors
Zaharoff, D; Barr, R; Li, CY; Yuan, F
MLA Citation
Zaharoff, D, Barr, R, Li, CY, and Yuan, F. "Mobility of plasmid DNA subject to pulsed electric fields." Annals of Biomedical Engineering 28.SUPPL. 1 (2000): S-25.
Source
scival
Published In
Annals of Biomedical Engineering
Volume
28
Issue
SUPPL. 1
Publish Date
2000
Start Page
S
End Page
25

Re: Initial stages of tumor cell-induced angiogenesis: Evaluation via skin window chambers in rodent models [3] (multiple letters)

Authors
Hoffman, RM; Li, C-Y; Shan, S; Huang, Q; Dewhirst, MW
MLA Citation
Hoffman, RM, Li, C-Y, Shan, S, Huang, Q, and Dewhirst, MW. "Re: Initial stages of tumor cell-induced angiogenesis: Evaluation via skin window chambers in rodent models [3] (multiple letters)." Journal of the National Cancer Institute 92.17 (2000): 1445-1446.
PMID
10974089
Source
scival
Published In
Journal of the National Cancer Institute
Volume
92
Issue
17
Publish Date
2000
Start Page
1445
End Page
1446

Delivery of plasmid DNA through intratumoral infusion and electroporation

We investigated DNA transport in the interstitial space and across cell membrane facilitated by intratumoral infusion and in vivo electroporation, respectively. In the study, a rat fibrosarcoma was perfused ex vivo, and apparent hydraulic conductivity (Kapp) was quantified under different perfusion conditions. In addition, three plasmid DNA vectors were infused into solid tumors. Immediately after infusion, tumors were treated with or without electric pulses. Gene expression and tumor growth delay were determined at different time points after electroporation. We found that Kapp was very sensitive to the perfusion pressure, presumably due to perfusion-induced tissue deformation. Treatment of tumors with electric pulse facilitated gene expression in vivo. The growth of tumors treated with plasmid DNA encoding interleukin 12 (IL-12) and electric pulses was slower than those treated with IL-12 or electric pulses alone. These data suggest that gene delivery in solid tumors could be improved significantly through combination of intratumoral infusion and in vivo electroporation.

Authors
Yuan, F; Zaharoff, D; Zhang, X-Y; Lohr, F; Dewhirst, MW; Li, C-Y
MLA Citation
Yuan, F, Zaharoff, D, Zhang, X-Y, Lohr, F, Dewhirst, MW, and Li, C-Y. "Delivery of plasmid DNA through intratumoral infusion and electroporation." American Society of Mechanical Engineers, Bioengineering Division (Publication) BED 48 (2000): 173-176.
Source
scival
Published In
American Society of Mechanical Engineers, Bioengineering Division (Publication) BED
Volume
48
Publish Date
2000
Start Page
173
End Page
176

Noninvasive visualization of tumors in rodent dorsal skin window chambers.

Authors
Huang, Q; Shan, S; Braun, RD; Lanzen, J; Anyrhambatla, G; Kong, G; Borelli, M; Corry, P; Dewhirst, MW; Li, CY
MLA Citation
Huang, Q, Shan, S, Braun, RD, Lanzen, J, Anyrhambatla, G, Kong, G, Borelli, M, Corry, P, Dewhirst, MW, and Li, CY. "Noninvasive visualization of tumors in rodent dorsal skin window chambers." Nat Biotechnol 17.10 (October 1999): 1033-1035.
PMID
10504711
Source
pubmed
Published In
Nature Biotechnology
Volume
17
Issue
10
Publish Date
1999
Start Page
1033
End Page
1035
DOI
10.1038/13736

Deletions and point mutations of p16,p15 gene in primary tumors and tumor cell lines.

Aberrations of chromosome 9 p21-22 are involved in the genesis of many forms of cancer. The gene p16 and p15 have been assigned to this region. Both p16 and p15 are an inhibitor of cyclin D-cdk4,cyclin D-cdk6 complex and have been implicated in a wide variety of cancer types, including the germline of patients with familial melanoma. In order to investigate and compare the status of p16,p15 gene in primary tumors and cell lines, we examined 357 primary tumors and 29 cell lines derived from diverse tumor types. In addition to analysis of these primary tumors and cell lines, blood specimens from 91 patients either with sporadic multiple cancers or from cancer-prone families were also analyzed. The data showed the following: 1) Homozygous deletions of p16,p15 were comparatively rare and far less common than previously reported, although hemizygous deletions were observed in a significant fraction of many tumor types; 2) the incidence of p16,p15 deletions (either homozygous deletions or heterozygous deletions) varied significantly among different tumor types; 3) most deletions involved in both p16 and p15 genes; 4) sequence variations in the coding sequence of p16,p15 were comparatively rare among these tumor types, though mutations and polymorphisms were identified; 5) some tumors which showed LOH at 9p, containing p16 and p15 gene, did not show deletions or point mutations in the p16,p15 gene. 6) In a subset of retinoblastoma and osteosarcoma where no Rb gene mutations were present a significant fraction was found to contain p16,p15 gene deletions.

Authors
Yonghao, T; Qian, H; Chuanyuan, L; Yandell, DW
MLA Citation
Yonghao, T, Qian, H, Chuanyuan, L, and Yandell, DW. "Deletions and point mutations of p16,p15 gene in primary tumors and tumor cell lines." Chinese medical sciences journal = Chung-kuo i hsueh ko hsueh tsa chih / Chinese Academy of Medical Sciences 14.4 (1999): 200-205.
PMID
12894891
Source
scival
Published In
Chinese medical sciences journal = Chung-kuo i hsueh ko hsueh tsa chih / Chinese Academy of Medical Sciences
Volume
14
Issue
4
Publish Date
1999
Start Page
200
End Page
205

Influence of p53 expression on radiosensitivity of human normal and tumor cells

The radiosensitivity of normal human fibroblasts is p53 dependent and associated with the loss of cells from the cycling population as the result of an irreversible G1 arrest; cells lacking normal p53 function show no arrest and are more radioresistant. Under conditions in which the repair of potentially lethal radiation damage is facilitated, the fraction of cells arrested in G1 is reduced and survival is enhanced. The response of human tumor cells differs significantly. The radiation-induced G1 arrest is minimal or absent in p53+ tumor cells, and loss of normal p53 function has no consistent effect on their radiosensitivity. These results suggest that p53 status may not be a useful predictive marker for the response of human solid tumors to radiation therapy.

Authors
Little, JB; Li, CY; Nagasawa, H; Huang, H
MLA Citation
Little, JB, Li, CY, Nagasawa, H, and Huang, H. "Influence of p53 expression on radiosensitivity of human normal and tumor cells." Journal de Chimie Physique et de Physico-Chimie Biologique 95.4 (1998): 820-829.
Source
scival
Published In
Journal de Chimie Physique et de Physico-Chimie Biologique
Volume
95
Issue
4
Publish Date
1998
Start Page
820
End Page
829

Abrogation of p53 function by HPV16 E6 gene delays apoptosis and enhances mutagenesis but does not alter radiosensitivity in TK6 human lymphoblast cells

In order to gain a better understanding of the role of p53 in radiation-induced mitotic failure, apoptosis and mutagenesis, we introduced the HPV16 E6 gene via a retroviral vector into the TK6 human lymphoblast cell line which expresses wild type p53. Abrogation of p53 function by E6 resulted in a delayed and reduced apoptotic response and a moderate increase in the frequency of mutations at the thymidine kinase (tk) locus following γ-irradiation, but failed to alter radiosensitivity. The apoptotic response of the E6-transduced line was intermediate between that of wild type TK6 and the WTK1 cell line. WTK1 is derived from the same parental cell line as TK6 but expresses mutant p53. The spontaneous and γ-ray-induced mutation frequencies in E6-transduced TK6 cells, although higher than that of the parental TK6 cell line, were still much lower than that of the WTK1 line. No effect on apoptosis, radiosensitivity or mutability was observed when the HPV16 E6 gene was introduced into the WTK1 cells. These results indicate that p53 does not regulate the radiosensitivity of TK6 cells through the apoptotic pathway. Furthermore, the previously observed enhanced radioresistance and mutability in WTK1 cells must be attributed to a more complex mechanism than p53 status alone.

Authors
Yu, Y; Li, C-Y; Little, JB
MLA Citation
Yu, Y, Li, C-Y, and Little, JB. "Abrogation of p53 function by HPV16 E6 gene delays apoptosis and enhances mutagenesis but does not alter radiosensitivity in TK6 human lymphoblast cells." Oncogene 14.14 (1997): 1661-1667.
PMID
9135067
Source
scival
Published In
Oncogene: Including Oncogene Reviews
Volume
14
Issue
14
Publish Date
1997
Start Page
1661
End Page
1667

Genomic instability and radiation mutagenesis

An increase in the frequency of spontaneous mutations occurs in some cell populations arising from single cells surviving radiation exposure. This mutator phenotype may persist over many cell divisions. The spectrum of DNA structural changes at the hprt locus observed in these delayed mutations differs significantly from that occurring in direct X-ray-induced mutations. In other experiments, an increased frequency of coincident, second-site mutations was found in minisatellite and microsatellite loci in cells selected for mutations of the thymidine kinase (tk) gene. Together these results suggest that radiation may induce a genome-wide mutational process that can persist over many generations of cell replication. It is tempting to speculate that such a global, trans-acting mutagenic process would enhance the possibility of the occurrence of mutational events at the multiple loci required for the development of cancer.

Authors
Little, JB; Li, C; Nagasawa, H; Pfenning, T; Vetrovs, H
MLA Citation
Little, JB, Li, C, Nagasawa, H, Pfenning, T, and Vetrovs, H. "Genomic instability and radiation mutagenesis." Journal de Chimie Physique et de Physico-Chimie Biologique 93.1 (December 1, 1996): 157-164.
Source
scopus
Published In
Journal de chimie physique et de physicochimie biologique
Volume
93
Issue
1
Publish Date
1996
Start Page
157
End Page
164

Radio-induced modulation of transforming growth factor beta1 sensitivity in a p53 wild-type human colorectal-cancer cell line.

Unlike normal intestinal cells, colorectal-carcinoma cell lines are usually not responsive to transforming growth factor beta1. The cyclin-dependent kinase inhibitor p21 that is induced by X irradiation in cells expressing normal p53 can also be induced by TGF-beta1 by a p53-independent pathway. We have investigated possible interactions between ionizing radiation and TGF-beta1, using a panel of 8 human colorectal-cancer cell lines varying in p53 status and sensitivity to the cyto-inhibitory effect of TGF-beta1. Heterogeneity in the radiosensitivity of these cell lines was observed, with SF2 (surviving fraction after irradiation with 2 Gy) ranging from 0.19 to 0.82. Radioresistance (high SF2 values) was in general associated with abnormal expression of p53. An effect of TGF-beta1 treatment on radiosensitivity was observed with one cell line only (LS513), and manifested by enhancement of the cytotoxic effect of radiation. In an experiment with fractionated irradiation during continuous exposure to TGF-beta1, there was no change in the intrinsic radiosensitivity of LS513 cells, though irradiated cells treated with TGF-beta1 were more sensitive to the first radiation dose. Irradiated LS513 colorectal-cancer and Mv-1-Lu epithelial cells were significantly more sensitive to TGF-beta1 than were unirradiated controls, whereas no change was observed in the TGF-beta1 sensitivity of irradiated LS1034 cells. Radio-induced modulation of TGF-beta1 sensitivity was transitory and declined before the decline to baseline level of p21 mRNA expression. On the basis of these results, we postulate that radiation-induced sensitization to TGF-beta1 occurs in TGF-beta1-sensitive cells expressing wild-type p53.

Authors
Suardet, L; Li, C; Little, JB
MLA Citation
Suardet, L, Li, C, and Little, JB. "Radio-induced modulation of transforming growth factor beta1 sensitivity in a p53 wild-type human colorectal-cancer cell line." International journal of cancer 68.1 (September 1996): 126-131.
PMID
8895552
Source
epmc
Published In
International Journal of Cancer
Volume
68
Issue
1
Publish Date
1996
Start Page
126
End Page
131
DOI
10.1002/(sici)1097-0215(19960927)68:1<126::aid-ijc22>3.0.co;2-8

Abrogation of p53 function by transfection of HPV16 E6 gene does not enhance resistance of human tumour cells to ionizing radiation

Suppression of wild-type p53 expression has been shown to enhance the radiation resistance of human diploid fibroblasts, but results concerning the role oil p53 expression m the sensitivity of human tumour cells have been conflicting. In order to address this question, we transfected four human tumour cell lines with the human papilloma virus 16 E6 gene and compared the radiosensitivity of subclones expressing E6 with that of subclones transfected with the neo gene alone. E6 binds to wild-type p53 promoting its degradation and abrogating its function. Two of these cell lines, one derived from a squamous cell carcinoma and the other an osteogenic sarcoma, expressed mild-type p53. The other two cell lines were of similar origins and histologies but expressed mutant or no p53 (null). Insertion of E6 into the cell was accomplished by two techniques: (1) to-transfection of plasmid vectors containing neo and E6; (2) infection with a retroviral vector containing neo and E6. Multiple transfected subclones were examined for each cell line. Transfection with E6 and abrogation of p53 function had no significant influence on the radiosensitivity of any of the cell lines tested. In particular, there was no evidence that loss of wild type p53 function increased the resistance of these human tumour cell lines to ionizing radiation.

Authors
Huang, H; Li, C-Y; Little, JB
MLA Citation
Huang, H, Li, C-Y, and Little, JB. "Abrogation of p53 function by transfection of HPV16 E6 gene does not enhance resistance of human tumour cells to ionizing radiation." International Journal of Radiation Biology 70.2 (1996): 151-160.
PMID
8794844
Source
scival
Published In
International Journal of Radiation Biology (Informa)
Volume
70
Issue
2
Publish Date
1996
Start Page
151
End Page
160
DOI
10.1080/095530096145148

Radio-induced modulation of transforming growth factor β1 sensitivity in a p53 wild-type human colorectal-cancer cell line

Unlike normal intestinal cells, colorectal-carcinoma cell lines are usually not responsive to transforming growth factor pi. The cyclin-dependent kinase inhibitor p21 that is induced by X irradiation in cells expressing normal p53 can also be induced by TGF-β1 by a p53-independent pathway. We have investigated possible interactions between ionizing radiation and TGF-β1, using a panel of 8 human colorectal-cancer cell lines varying in p53 status and sensitivity to the cyto-inhibitory effect of TGF-β1. Heterogeneity in the radiosensitivity of these cell lines was observed, with SF2 (surviving fraction after irradiation with 2 Gy) ranging from 0.19 to 0.82. Radioresistance (high SF2 values) was in general associated with abnormal expression of p53. An effect of TGF-β1 treatment on radiosensitivity was observed with one cell line only (LS513), and manifested by enhancement of the cytotoxic effect of radiation. In an experiment with fractionated irradiation during continuous exposure to TGF-β1, there was no change in the intrinsic radiosensitivity of LS513 sells, though irradiated cells treated with TGF-β1 were more sensitive to the first radiation dose. Irradiated LS513 colorectal-cancer and Mv-1-Lu epithelial cells were significantly more sensitive to TGF-β1 than were unirradiated controls, whereas no change was observed in the TGF-β1 sensitivity of irradiated LS1034 cells. Radio-induced modulation of TGF-β1 sensitivity was transitory and declined before the decline to baseline level of p21 mRNA expression. On the basis of these results, we postulate that radiation-induced sensitization to TGF-β1 occurs in TGF-β1-sensitive cells expressing wild-type p53.

Authors
Suardet, L; Chuan, LI; Little, JB
MLA Citation
Suardet, L, Chuan, LI, and Little, JB. "Radio-induced modulation of transforming growth factor β1 sensitivity in a p53 wild-type human colorectal-cancer cell line." International Journal of Cancer 68.1 (1996): 126-131.
Source
scival
Published In
International Journal of Cancer
Volume
68
Issue
1
Publish Date
1996
Start Page
126
End Page
131
DOI
10.1002/(SICI)1097-0215(19960927)68:1<126::AID-IJC22>3.0.CO;2-8

Role of tumor suppressor genes in determining radiation-induced G1 arrest and transformation in human cells

Authors
Li, C-Y; Nagasawa, H; Little, JB
MLA Citation
Li, C-Y, Nagasawa, H, and Little, JB. "Role of tumor suppressor genes in determining radiation-induced G1 arrest and transformation in human cells." Radiation Oncology Investigations 3.6 (1996): 268-271.
Source
scival
Published In
Radiation Oncology Investigations
Volume
3
Issue
6
Publish Date
1996
Start Page
268
End Page
271

Radiation-induced irreversible G(0)/G(1) block is abolished in human diploid fibroblasts transfected with the human papilloma virus E6 gene: Implication of the p53-Cip1/WAF1 pathway

It has been shown previously with human diploid fibroblasts that a fraction of cells remains irreversibly blocked in the G(0)/G(1) phase of the cell cycle when the cells are irradiated in confluent, density-inhibited cultures and released by subculture to low density. In the present study we demonstrate that this G(0)/G(1) block is abolished when a human fibroblast cell strain is transfected with the human papilloma virus 16 E6 gene. Corresponding to the abolition of the G(0)/G(1) block in the E6-transfected cells, the expression of both the p53 and WAF1 genes is also abolished, suggesting that the p53 pathway of DNA damage response may be involved in this phenomenon.

Authors
Li, C; Nagasawa, H; Tsang, NM; Little, JB
MLA Citation
Li, C, Nagasawa, H, Tsang, NM, and Little, JB. "Radiation-induced irreversible G(0)/G(1) block is abolished in human diploid fibroblasts transfected with the human papilloma virus E6 gene: Implication of the p53-Cip1/WAF1 pathway." International Journal of Oncology 6.1 (January 1, 1995): 233-236.
Source
scopus
Published In
International journal of oncology
Volume
6
Issue
1
Publish Date
1995
Start Page
233
End Page
236

Absence of radiation-induced G1 arrest in two closely related human lymphoblast cell lines that differ in p53 status

In order to examine more precisely the role of p53 in the activation of the G1/S checkpoint by ionizing radiation, we examined two human lymphoblast cell lines derived from the same donor. The TK6 line had a doubling time of 12.2 h and expressed wild type p53, while the WTK1 line had a doubling time of 12.7 h and expressed mutant p53. The two lines differ significantly in their susceptibility to radiation-induced cell killing and apoptosis. Cells were examined by flow cytometry at regular intervals from 0 to 12 h after irradiation with two different doses designed to yield equivalent survival levels in both cell lines. In some experiments, cells were incubated with colcemid to block them in the first postirradiation mitosis and prevent contamination of the flow cytometric profiles with second cycle cells. There was no significant difference between the two cell lines in the progression of irradiated cells out of G1 and into the S and G2 phases of the cell cycle. In particular, there was no evidence for a prolonged arrest in G1 in the TK6 cell line expressing wild type p53. Furthermore, expression of the p53 downstream genes WAF1/CIP1 and RB appeared normal in TK6 cells. These results suggest that factors other than those in the p53 signal transduction pathway alone may be required to activate the G1/S checkpoint in irradiated human cells and that apoptosis and G1 arrest may utilize different pathways.

Authors
Little, JB; Nagasawa, H; Keng, PC; Yu, Y; Li, C-Y
MLA Citation
Little, JB, Nagasawa, H, Keng, PC, Yu, Y, and Li, C-Y. "Absence of radiation-induced G1 arrest in two closely related human lymphoblast cell lines that differ in p53 status." Journal of Biological Chemistry 270.19 (1995): 11033-11036.
PMID
7744731
Source
scival
Published In
Journal of Biological Chemistry
Volume
270
Issue
19
Publish Date
1995
Start Page
11033
End Page
11036
DOI
10.1074/jbc.270.19.11033

Relationship between radiation-induced G1 phase arrest and p53 function in human tumor cells

Three widely studied cell lines were used to examine the nature of the G1 arrest induced in human tumor cells by ionizing radiation and its relation to p53 status. Cell lines MCF-7 and RKO express wild-type p53, whereas HT29 expresses mutant p53. Exponentially growing cells were irradiated with 6 Gy, and the progression of G1 cells into S phase was monitored at regular intervals by flow microfluorimetric and continuous labeling autoradiographic techniques. In some experiments, cells were incubated with Colcemid prior to irradiation in order to block them in mitosis and to prevent the accumulation of cells in the second postirradiation G1 phase. No evidence of a significant arrest at the first post-irradiation G1-S checkpoint was observed in any of the three cell lines. These results suggest that p53 function alone does not control the progression of irradiated human tumor cells from G1 into S during the first post-irradiation cell cycle. In particular, we found no evidence that radiation induced a prolonged G1 arrest in tumor cells expressing wild-type p53 as has been reported by some investigators.

Authors
Nagasawa, H; Li, C-Y; Maki, CG; Imrich, AC; Little, JB
MLA Citation
Nagasawa, H, Li, C-Y, Maki, CG, Imrich, AC, and Little, JB. "Relationship between radiation-induced G1 phase arrest and p53 function in human tumor cells." Cancer Research 55.9 (1995): 1842-1846.
PMID
7728750
Source
scival
Published In
Cancer Research
Volume
55
Issue
9
Publish Date
1995
Start Page
1842
End Page
1846

Abrogation of p53 function by transfection of HPV16 E6 gene enhances the resistance of human diploid fibroblasts to ionizing radiation

In order to examine the role of p53 expression on the sensitivity of cells to radiation-induced reproductive failure, we examined the radiosensitivity of a human diploid fibroblast cell strain (AG1521) before and after transfection with the E6 or E6/E7 genes of human papillomavirus 16 (HPV16). HPV E6 binds to p53, promoting its degradation and abrogating wild-type p53 function. AG1521 cells transfected with either E6 or E6/E7 showed no radiation induction of either p53 or WAF1/Cip1. The radioresistance of these cells were significantly increased; the D0 of the survival curves rose from 130 ± 4 cGy for wild type (neo-transfected) cells to 178-192 cGy for three subclones transfected with E6 alone, and 151-218 cGy for eight subclones transfected with E6/E7. The change in radiosensitivity took place before the process of cellular immortalization and transformation produced by transfection with these genes. Thus, the effect on radiosensitivity appears to be an early effect of the loss of p53 function in non-transformed cells, perhaps related to the loss of the G1 checkpoint and of the capacity for programmed death amongst radiation damaged cells.

Authors
Tsang, N-M; Nagasawa, H; Li, C; Little, JB
MLA Citation
Tsang, N-M, Nagasawa, H, Li, C, and Little, JB. "Abrogation of p53 function by transfection of HPV16 E6 gene enhances the resistance of human diploid fibroblasts to ionizing radiation." Oncogene 10.12 (1995): 2403-2408.
PMID
7784090
Source
scival
Published In
Oncogene: Including Oncogene Reviews
Volume
10
Issue
12
Publish Date
1995
Start Page
2403
End Page
2408

Potential role of WAF1/Cip1/p21 as a mediator of TGF-β cytoinhibitory effect

Transforming growth factor-β (TGF-β) inhibits cell cycle progression of many types of human cells by arresting them in the G1 phase of the cell cycle. The arrest is mediated through interactions of various cyclin- dependent protein kinases (CDKs) and their inhibitors. We demonstrate that treatment with TGF-β induces increased levels of WAF1/Cip1/p21, a potent inhibitor of various cyclin-CDK kinase activities, in two colon cancer cell lines (LS1034 and LS513), which are sensitive to TGF-β-induced growth arrest. The induction in at least one of these cells lines (LS1034, p53-) is p53-independent. No WAF1 induction was observed after TGF-β treatment in a third cell line (HT-29), which is completely insensitive to the cytoinhibitory effect of TGF-β. In both LS513 and LS1034, WAF1 induction correlated with reduced cyclin E-associated kinase activity in vitro and suppression of the retinoblastoma susceptibility gene (Rb) protein phosphorylation in vivo. In addition, WAF1 was physically associated with cyclin E in the two sensitive cell lines. These results suggest that WAF1/Cip1/p21 is a mediator of cellular sensitivity to TGF-β.

Authors
Li, C-Y; Suardet, L; Little, JB
MLA Citation
Li, C-Y, Suardet, L, and Little, JB. "Potential role of WAF1/Cip1/p21 as a mediator of TGF-β cytoinhibitory effect." Journal of Biological Chemistry 270.10 (1995): 4971-4974.
PMID
7890601
Source
scival
Published In
Journal of Biological Chemistry
Volume
270
Issue
10
Publish Date
1995
Start Page
4971
End Page
4974
DOI
10.1074/jbc.270.10.4971

Diminished capacity for p53 in mediating a radiation-induced G1 arrest in established human tumor cell lines

It has been reported that the p53 gene mediates an ionizing radiation-induced G1 arrest in mammalian cells. To further characterize this important phenomenon, a panel of seven human diploid fibroblast cell strains and 14 human tumor cell lines from a variety of sources with both wild-type and mutant p53 status were assayed for their susceptibility to G1 arrest after γ-ray irradiation by a continuous labeling [3H]thymidine incorporation technique. An irreversible G1-block involving 20-70% of the cell population was observed in diploid fibroblasts irradiated with 4 Gy. The block was abolished by transfection with the Human Papilloma Virus E6 gene and in an ataxia telangiectasia (AT) cell line, indicating a role for the AT and p53 genes respectively in this process. In contrast to wild-type normal fibroblast cell strains, the G1-block in all tumor cell lines was significantly reduced, irrespective of their p53 status. None of the nine human tumor cell lines with mutant p53 genes showed a significant G1-block following irradiation with 4 Gy. Among the five tumor cell lines expressing wild-type p53, two showed no apparent G1-block. The remaining three showed a G1-block involving only 8-15% of the cell population, a block much smaller in magnitude than that seen in diploid fibroblasts. Finally, a diploid fibroblast cell strain and a tumor cell line, both showing a normal p53 and p21/WAF1 expression pattern, were examined for pRb phosphorylation before and after irradiation. The diploid fibroblast cell strain showed a significant G1-arrest and a clear inhibition of pRb phosphorylation by irradiation whereas the tumor cells showed no G1-arrest and no inhibition of pRb phosphorylation. These results suggest that (1) multiple genetic factors may modulate the occurrence and magnitude of the G1-arrest induced by exposure to ionizing radiation, (2) the capacity for p53 to mediate a radiation-induced G1 arrest is significantly reduced in tumor cells, (3) the disruption of G1-block modulating factor(s) other than p53 may be an important step in carcinogenesis.

Authors
Li, C-Y; Nagasawa, H; Dahlberg, WK; Little, JB
MLA Citation
Li, C-Y, Nagasawa, H, Dahlberg, WK, and Little, JB. "Diminished capacity for p53 in mediating a radiation-induced G1 arrest in established human tumor cell lines." Oncogene 11.9 (1995): 1885-1892.
PMID
7478618
Source
scival
Published In
Oncogene
Volume
11
Issue
9
Publish Date
1995
Start Page
1885
End Page
1892

Elevated frequency of microsatellite mutations in TK6 human lymphoblast clones selected for mutations at the thymidine kinase locus

A major question in carcinogenesis is, How can a normal cell accumulate multiple mutations in different genes on different chromosomes, when the mutation rate of each gene is in the range of 10-8 to 10-5 per cell division? We hypothesize that many mutations may not be isolated events but rather are accompanied by concomitant mutations elsewhere in the genome. To test this hypothesis, 331 independent clones selected for new mutations at the thymidine kinase (TK) locus on chromosome 17q, and 243 nonselected control clones were examined for mutations in 12 random microsatellite loci dispersed throughout the genome. A total of 24 second-site mutations were identified in the TK mutant clones, compared with 3 in the control clones not selected for mutations at TK. The mutations include small deletions, insertions, and loss of heterozygosity. These results provide evidence that a global trans-acting mutagenic process exists in human cells. The activation of this process could be responsible for causing multiple essential mutations in tumor cells.

Authors
Li, C-Y; Yandell, DW; Little, JB
MLA Citation
Li, C-Y, Yandell, DW, and Little, JB. "Elevated frequency of microsatellite mutations in TK6 human lymphoblast clones selected for mutations at the thymidine kinase locus." Molecular and Cellular Biology 14.7 (1994): 4373-4379.
PMID
8007946
Source
scival
Published In
Molecular and Cellular Biology
Volume
14
Issue
7
Publish Date
1994
Start Page
4373
End Page
4379

Brief report: Lymphoma of donor origin occurring in the porta hepatis of a transplanted liver

Authors
Spiro, IJ; Yandell, DW; Li, C; Saini, S; Ferry, J; Powelson, J; Katkov, WN; Cosimi, AB
MLA Citation
Spiro, IJ, Yandell, DW, Li, C, Saini, S, Ferry, J, Powelson, J, Katkov, WN, and Cosimi, AB. "Brief report: Lymphoma of donor origin occurring in the porta hepatis of a transplanted liver." New England Journal of Medicine 329.1 (1993): 27-29.
PMID
8505941
Source
scival
Published In
New England Journal of Medicine
Volume
329
Issue
1
Publish Date
1993
Start Page
27
End Page
29
DOI
10.1056/NEJM199307013290105

Immature teratomas of different origin carried by a pregnant mother and her fetus

We describe the case of a pregnant mother and her fetus who both carried teratomas during the pregnancy. The fetus was diagnosed at 38 weeks' gestation to have an intracranial mass, which was later determined to be an immature teratoma. During a cesarean section delivery, an ovarian tumor was found in the 27-year-old mother that was also diagnosed to be an immature teratoma. Because of the similar histology of the tumors carried by both mother and child, a single clonal origin was suspected. Using polymerase chain reaction (PCR) and electrophoresis of highly polymorphic DNA satellite sequences, we determined that the origin of the intracranial teratoma carried by the child was independent of the mother's tumor. We also examined the p53 tumor suppressor gene in constitutional cells from both mother and child for the possible presence of a cancer-predisposing inherited mutation, but none was found. To our knowledge, this is the first report of the simultaneous occurrence of independent malignant immature teratomas in a mother and child during pregnancy.

Authors
Poremba, C; Dockhorn-Dworniczak, B; Merritt, V; Li, CY; Heidl, G; Tauber, PF; Bocker, W; Yandell, DW
MLA Citation
Poremba, C, Dockhorn-Dworniczak, B, Merritt, V, Li, CY, Heidl, G, Tauber, PF, Bocker, W, and Yandell, DW. "Immature teratomas of different origin carried by a pregnant mother and her fetus." Diagnostic Molecular Pathology 2.2 (1993): 131-136.
Source
scival
Published In
Diagnostic Molecular Pathology
Volume
2
Issue
2
Publish Date
1993
Start Page
131
End Page
136

Evidence for coincident mutations in human lymphoblast clones selected for functional loss of a thymidine kinase gene

A mitotic 'recombination-competent state' inducible by x-irradiation is thought to exist in yeast. We sought evidence for such a process in mammalian cells by examining the occurrence of mutations at unlinked loci in clones derived from a human lymphoblast cell line. A total of 169 independent clones that arose spontaneously or after exposure to x-rays or ethyl methanesulfonate were selected for new somatic mutations at the thymidine kinase gene on chromosome 17q. They were subsequently screened for coincident mutations by use of variable-number-of-tandem-repeat probes located on different chromosomes. Three coincident mutations were positively identified by Southern analysis on chromosomes 7 and 14; they included one that produced a new allele and two that caused loss of allele heterozygosity. Densitometric analysis of the latter two indicated the presence of two copies of the remaining allele. Several possible coincident genetic events were also observed on chromosome 17. These findings revealed a coincident mutant fraction of about 10-2/cell, whereas the expected mutation fraction at these loci is less than 10-4/cell. These results may thus provide the first molecular evidence that a 'global' mutational process capable of inducing genetic instability exists in mammalian cells.

Authors
Li, CY; Yandell, DW; Little, JB
MLA Citation
Li, CY, Yandell, DW, and Little, JB. "Evidence for coincident mutations in human lymphoblast clones selected for functional loss of a thymidine kinase gene." Molecular Carcinogenesis 5.4 (1992): 270-277.
Source
scival
Published In
Molecular Carcinogenesis
Volume
5
Issue
4
Publish Date
1992
Start Page
270
End Page
277
DOI
10.1002/mc.2940050407

Molecular mechanisms of spontaneous and induced loss of heterozygosity in human cells in vitro

The human TK6 lymphoblast cell line is heteroallelic at the thymidine kinase (TK) locus, with one functional and one nonfunctional allele. Cells that have undergone loss of heterozygosity (LOH) at TK can be selected and cloned in an in vitro assay. In order to study the extent of LOH, we have analyzed a total of 166 thymidine kinase-deficient mutants that arose either spontaneously or following induction by X-ray or ethyl methane sulfonate (EMS) using DNA probes in and around the TK gene on chromosome 17. Two distinct groups of mutants with different doubling times were identified. Among slow-growth mutants, the predominant change for both spontaneous and induced mutants was LOH that generally extended through the entire TK gene to both proximal and distal markers on 17q. While the majority of both spontaneous and X-ray-induced normal-growth mutants showed LOH, this was considerably more localized in scale for X-ray-induced mutants, which rarely involved the distal marker. LOH was rare among EMS-induced normal-growth mutants. LOH was never observed with a 17p marker, indicating that nondisjunctional events were not involved in any of the mutant clones examined. Densitometric analysis of the LOH mutants indicated mitotic recombination was a likely mechanism in more than half the spontaneous LOH mutants in both groups, whereas most induced mutants appeared to arise from simple deletions. © 1992 Plenum Publishing Corporation.

Authors
Li, C-Y; Yandell, DW; Little, JB
MLA Citation
Li, C-Y, Yandell, DW, and Little, JB. "Molecular mechanisms of spontaneous and induced loss of heterozygosity in human cells in vitro." Somatic Cell and Molecular Genetics 18.1 (1992): 77-87.
PMID
1546370
Source
scival
Published In
Somatic cell and molecular genetics
Volume
18
Issue
1
Publish Date
1992
Start Page
77
End Page
87
DOI
10.1007/BF01233450
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