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Devi, Gayathri R.

Overview:

Dr. Devi’s research interests include functional genomics, anti-cancer drug discovery and development, mechanisms of cancer cell signaling, tumor immunity and applications thereof for overcoming therapeutic resistance in cancer.

The lab has established prostate, inflammatory breast cancer and ovarian cellular and tumor models.

Positions:

Associate Professor in Surgery

Surgery, Surgical Sciences
School of Medicine

Associate Professor in Pathology

Pathology
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

Ph.D. 1998

Ph.D. — University of Nebraska College of Medicine

News:

Grants:

Translational Research in Surgical Oncology

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

Neonatal Porcine Islet Xenografts for the Treatment of Type 1 Diabetes

Administered By
Surgery, Abdominal Transplant Surgery
AwardedBy
National Institutes of Health
Role
Co Investigator
Start Date
September 01, 2014
End Date
August 31, 2020

Viral Oncology Training Grant

Administered By
Molecular Genetics and Microbiology
AwardedBy
National Institutes of Health
Role
Participating Faculty Member
Start Date
July 01, 1980
End Date
June 30, 2019

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

Novel Immune Modulating Cellular Vaccine for Prostate Cancer Immunotherapy

Administered By
Surgery, Surgical Sciences
AwardedBy
Department of Defense
Role
Investigator
Start Date
September 30, 2013
End Date
September 29, 2017

Developing a HER3 Vaccine to Prevent Resistance to Endocrine Therapy

Administered By
Surgery, Surgical Sciences
AwardedBy
Department of Defense
Role
Co Investigator
Start Date
September 30, 2012
End Date
September 29, 2017

GLI1 Inhibition to Enhance Chemo- and Targeted-Therapies in Inflammatory Breast Cancer

Administered By
Surgery, Surgical Sciences
AwardedBy
North Carolina Central University
Role
Principal Investigator
Start Date
August 15, 2013
End Date
August 14, 2017

Resveratrol, Carbohydrate Restriction and Prostate Cancer Progression

Administered By
Surgery, Urology
AwardedBy
National Institutes of Health
Role
Investigator
Start Date
September 15, 2008
End Date
July 31, 2014

Role of XIAP in Therapeutic Resistance in Inflammatory Breast Cancer

Administered By
Surgery
AwardedBy
Dept. of the Army -- USAMRAA
Role
Principal Investigator
Start Date
July 01, 2008
End Date
August 31, 2010
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Publications:

Abstract LB-015: XIAP induction by the MAPK-eIF4G1 pathway drives NFκB activation in inflammatory breast cancer growth and therapeutic resistance

Authors
Evans, MK; Geradts, J; Edwards, C; Price, A; Arora, AJ; Aldrich, AJ; Ramirez, A; Robinson, TJ; Vermeulen, PB; van Laere, S; Devi, GR
MLA Citation
Evans, MK, Geradts, J, Edwards, C, Price, A, Arora, AJ, Aldrich, AJ, Ramirez, A, Robinson, TJ, Vermeulen, PB, van Laere, S, and Devi, GR. "Abstract LB-015: XIAP induction by the MAPK-eIF4G1 pathway drives NFκB activation in inflammatory breast cancer growth and therapeutic resistance." July 15, 2016.
Source
crossref
Published In
Cancer Research
Volume
76
Issue
14 Supplement
Publish Date
2016
Start Page
LB-015
End Page
LB-015
DOI
10.1158/1538-7445.AM2016-LB-015

Three-dimensional culture systems in cancer research: Focus on tumor spheroid model.

Cancer cells propagated in three-dimensional (3D) culture systems exhibit physiologically relevant cell-cell and cell-matrix interactions, gene expression and signaling pathway profiles, heterogeneity and structural complexity that reflect in vivo tumors. In recent years, development of various 3D models has improved the study of host-tumor interaction and use of high-throughput screening platforms for anti-cancer drug discovery and development. This review attempts to summarize the various 3D culture systems, with an emphasis on the most well characterized and widely applied model - multicellular tumor spheroids. This review also highlights the various techniques to generate tumor spheroids, methods to characterize them, and its applicability in cancer research.

Authors
Nath, S; Devi, GR
MLA Citation
Nath, S, and Devi, GR. "Three-dimensional culture systems in cancer research: Focus on tumor spheroid model." Pharmacology & therapeutics 163 (July 2016): 94-108.
PMID
27063403
Source
epmc
Published In
Pharmacology & Therapeutics
Volume
163
Publish Date
2016
Start Page
94
End Page
108
DOI
10.1016/j.pharmthera.2016.03.013

X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity.

Inflammatory breast cancer (IBC) is the deadliest, distinct subtype of breast cancer. High expression of epidermal growth factor receptors [EGFR or human epidermal growth factor receptor 2 (HER2)] in IBC tumors has prompted trials of anti-EGFR/HER2 monoclonal antibodies to inhibit oncogenic signaling; however, de novo and acquired therapeutic resistance is common. Another critical function of these antibodies is to mediate antibody-dependent cellular cytotoxicity (ADCC), which enables immune effector cells to engage tumors and deliver granzymes, activating executioner caspases. We hypothesized that high expression of anti-apoptotic molecules in tumors would render them resistant to ADCC. Herein, we demonstrate that the most potent caspase inhibitor, X-linked inhibitor of apoptosis protein (XIAP), overexpressed in IBC, drives resistance to ADCC mediated by cetuximab (anti-EGFR) and trastuzumab (anti-HER2). Overexpression of XIAP in parental IBC cell lines enhances resistance to ADCC; conversely, targeted downregulation of XIAP in ADCC-resistant IBC cells renders them sensitive. As hypothesized, this ADCC resistance is in part a result of the ability of XIAP to inhibit caspase activity; however, we also unexpectedly found that resistance was dependent on XIAP-mediated, caspase-independent suppression of reactive oxygen species (ROS) accumulation, which otherwise occurs during ADCC. Transcriptome analysis supported these observations by revealing modulation of genes involved in immunosuppression and oxidative stress response in XIAP-overexpressing, ADCC-resistant cells. We conclude that XIAP is a critical modulator of ADCC responsiveness, operating through both caspase-dependent and -independent mechanisms. These results suggest that strategies targeting the effects of XIAP on caspase activation and ROS suppression have the potential to enhance the activity of monoclonal antibody-based immunotherapy.

Authors
Evans, MK; Sauer, SJ; Nath, S; Robinson, TJ; Morse, MA; Devi, GR
MLA Citation
Evans, MK, Sauer, SJ, Nath, S, Robinson, TJ, Morse, MA, and Devi, GR. "X-linked inhibitor of apoptosis protein mediates tumor cell resistance to antibody-dependent cellular cytotoxicity." Cell death & disease 7 (January 28, 2016): e2073-.
Website
http://hdl.handle.net/10161/12402
PMID
26821068
Source
epmc
Published In
Cell Death and Disease
Volume
7
Publish Date
2016
Start Page
e2073
DOI
10.1038/cddis.2015.412

Delivery of Synthetic mRNA Encoding FOXP3 Antigen into Dendritic Cells for Inflammatory Breast Cancer Immunotherapy.

Dendritic cell (DC)-based vaccines are commonly used for cancer immunotherapy. To prepare vaccines, DCs are pulsed or transfected with either: (a) defined peptides of tumor-associated antigens, (b) total protein isolated from the tumor cell, (c) autologous total RNA isolated from the tumor cell, (d) synthetic tumor-antigen-encoding mRNA, or (e) genes that encode for specific tumor-associated antigens. Introduction of tumor-associated antigen(s) and subsequent generation of mature DCs that can stimulate tumor-antigen-specific cytotoxic T lymphocytes comprise the critical steps of cancer vaccine preparation. Here, we described a method of: (a) preparing and delivering synthetic FOXP3 mRNA into human DCs, (b) generating mature DCs,

Authors
Devi, GR; Nath, S
MLA Citation
Devi, GR, and Nath, S. "Delivery of Synthetic mRNA Encoding FOXP3 Antigen into Dendritic Cells for Inflammatory Breast Cancer Immunotherapy." Methods in molecular biology (Clifton, N.J.) 1428 (January 2016): 231-243.
PMID
27236803
Source
epmc
Published In
Methods in molecular biology (Clifton, N.J.)
Volume
1428
Publish Date
2016
Start Page
231
End Page
243
DOI
10.1007/978-1-4939-3625-0_15

Disulfiram (DSF) acts as a copper ionophore to induce copper-dependent oxidative stress and mediate anti-tumor efficacy in inflammatory breast cancer.

Cancer cells often have increased levels of reactive oxygen species (ROS); however, acquisition of redox adaptive mechanisms allows for evasion of ROS-mediated death. Inflammatory breast cancer (IBC) is a distinct, advanced BC subtype characterized by high rates of residual disease and recurrence despite advances in multimodality treatment. Using a cellular model of IBC, we identified an oxidative stress response (OSR) signature in surviving IBC cells after administration of an acute dose of an ROS inducer. Metagene analysis of patient samples revealed significantly higher OSR scores in IBC tumor samples compared to normal or non-IBC tissues, which may contribute to the poor response of IBC tumors to common treatment strategies, which often rely heavily on ROS induction. To combat this adaptation, we utilized a potent redox modulator, the FDA-approved small molecule Disulfiram (DSF), alone and in combination with copper. DSF forms a complex with copper (DSF-Cu) increasing intracellular copper concentration both in vitro and in vivo, bypassing the need for membrane transporters. DSF-Cu antagonized NFκB signaling, aldehyde dehydrogenase activity and antioxidant levels, inducing oxidative stress-mediated apoptosis in multiple IBC cellular models. In vivo, DSF-Cu significantly inhibited tumor growth without significant toxicity, causing apoptosis only in tumor cells. These results indicate that IBC tumors are highly redox adapted, which may render them resistant to ROS-inducing therapies. DSF, through redox modulation, may be a useful approach to enhance chemo- and/or radio-sensitivity for advanced BC subtypes where therapeutic resistance is an impediment to durable responses to current standard of care.

Authors
Allensworth, JL; Evans, MK; Bertucci, F; Aldrich, AJ; Festa, RA; Finetti, P; Ueno, NT; Safi, R; McDonnell, DP; Thiele, DJ; Van Laere, S; Devi, GR
MLA Citation
Allensworth, JL, Evans, MK, Bertucci, F, Aldrich, AJ, Festa, RA, Finetti, P, Ueno, NT, Safi, R, McDonnell, DP, Thiele, DJ, Van Laere, S, and Devi, GR. "Disulfiram (DSF) acts as a copper ionophore to induce copper-dependent oxidative stress and mediate anti-tumor efficacy in inflammatory breast cancer." Molecular oncology 9.6 (June 2015): 1155-1168.
PMID
25769405
Source
epmc
Published In
Molecular Oncology
Volume
9
Issue
6
Publish Date
2015
Start Page
1155
End Page
1168
DOI
10.1016/j.molonc.2015.02.007

Abstract P6-14-05: A novel link between anti-apoptotic signaling, NFκB, and SMAD7 in IBC pathobiology

Authors
Evans, MK; Sauer, SJ; Aldrich, AJ; Geradts, J; Vermeulen, P; Dirix, L; Van Laere, S; Devi, GR
MLA Citation
Evans, MK, Sauer, SJ, Aldrich, AJ, Geradts, J, Vermeulen, P, Dirix, L, Van Laere, S, and Devi, GR. "Abstract P6-14-05: A novel link between anti-apoptotic signaling, NFκB, and SMAD7 in IBC pathobiology." May 1, 2015.
Source
crossref
Published In
Cancer Research
Volume
75
Issue
9 Supplement
Publish Date
2015
Start Page
P6-14-05
End Page
P6-14-05
DOI
10.1158/1538-7445.SABCS14-P6-14-05

Modulation of murine breast tumor vascularity, hypoxia and chemotherapeutic response by exercise.

Exercise has been shown to improve postischemia perfusion of normal tissues; we investigated whether these effects extend to solid tumors. Estrogen receptor-negative (ER-, 4T1) and ER+ (E0771) tumor cells were implanted orthotopically into syngeneic mice (BALB/c, N = 11-12 per group) randomly assigned to exercise or sedentary control. Tumor growth, perfusion, hypoxia, and components of the angiogenic and apoptotic cascades were assessed by MRI, immunohistochemistry, western blotting, and quantitative polymerase chain reaction and analyzed with one-way and repeated measures analysis of variance and linear regression. All statistical tests were two-sided. Exercise statistically significantly reduced tumor growth and was associated with a 1.4-fold increase in apoptosis (sedentary vs exercise: 1544 cells/mm(2), 95% CI = 1223 to 1865 vs 2168 cells/mm(2), 95% CI = 1620 to 2717; P = .048), increased microvessel density (P = .004), vessel maturity (P = .006) and perfusion, and reduced intratumoral hypoxia (P = .012), compared with sedentary controls. We also tested whether exercise could improve chemotherapy (cyclophosphamide) efficacy. Exercise plus chemotherapy prolonged growth delay compared with chemotherapy alone (P < .001) in the orthotopic 4T1 model (n = 17 per group). Exercise is a potential novel adjuvant treatment of breast cancer.

Authors
Betof, AS; Lascola, CD; Weitzel, D; Landon, C; Scarbrough, PM; Devi, GR; Palmer, G; Jones, LW; Dewhirst, MW
MLA Citation
Betof, AS, Lascola, CD, Weitzel, D, Landon, C, Scarbrough, PM, Devi, GR, Palmer, G, Jones, LW, and Dewhirst, MW. "Modulation of murine breast tumor vascularity, hypoxia and chemotherapeutic response by exercise." Journal of the National Cancer Institute 107.5 (May 2015).
Website
http://hdl.handle.net/10161/12580
PMID
25780062
Source
epmc
Published In
Journal of the National Cancer Institute
Volume
107
Issue
5
Publish Date
2015
DOI
10.1093/jnci/djv040

Determination of an oxidative stress gene signature in inflammatory breast cancer patient tumors and development of a novel redox modulatory strategy in overcoming chemotherapy resistance and mediating anti-tumor efficacy

Authors
Devi, GR; Allensworth, JL; Evans, M; Ueno, N; McDonnell, D; Bertucci, F; Van Laere, S
MLA Citation
Devi, GR, Allensworth, JL, Evans, M, Ueno, N, McDonnell, D, Bertucci, F, and Van Laere, S. "Determination of an oxidative stress gene signature in inflammatory breast cancer patient tumors and development of a novel redox modulatory strategy in overcoming chemotherapy resistance and mediating anti-tumor efficacy." November 2014.
Source
wos-lite
Published In
European Journal of Cancer
Volume
50
Publish Date
2014
Start Page
31
End Page
31

Bisphenol a Interacts with Gper, Activates EGFR and ERK Signaling and Antagonizes Efficacy of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Breast Cancer Cells

Authors
Sauer, SJ; Davis, JB; Lyerly, HK; Shah, I; Williams, KP; Devi, GR
MLA Citation
Sauer, SJ, Davis, JB, Lyerly, HK, Shah, I, Williams, KP, and Devi, GR. "Bisphenol a Interacts with Gper, Activates EGFR and ERK Signaling and Antagonizes Efficacy of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Breast Cancer Cells." ENDOCRINE REVIEWS 35.3 (June 2014).
Source
wos-lite
Published In
Endocrine reviews
Volume
35
Issue
3
Publish Date
2014

The Role of Oxidative Stress in Breast Cancer

Breast cancer is the most common cancer in women worldwide and it accounts for the second highest morbidity and mortality. Disease etiology and progression is multifactorial and several risk factors associated with breast cancer exert their effects by modulation of oxidative stress status in the cells. Oxidative stress occurs due to an imbalance between reactive species and antioxidant defenses in the cells. Excess reactive species are deleterious in normal cells, while in cancer cells, they can lead to accelerated growth and survival correlating with an aggressive and therapy-resistant phenotype. Specifically, risk factors and their effect on the oxidative stress response are associated with breast cancer development, progression, and treatment outcome.This chapter provides a review of the accepted concepts, recent findings, and limitations in the understanding of the cross-talk between antioxidant capacity, redox-sensitive transcription factors, and cell survival/death signaling in oxidative stress response and redox adaptation in breast cancer. Addressing these matters and identifying pathway dysregulation is required for a rational basis to improve the design of redox-related therapeutics and clinical trials in breast cancer. © 2014 Elsevier Inc. All rights reserved.

Authors
Devi, GR; Allensworth, JL; Evans, MK; Sauer, SJ
MLA Citation
Devi, GR, Allensworth, JL, Evans, MK, and Sauer, SJ. "The Role of Oxidative Stress in Breast Cancer." Cancer: Oxidative Stress and Dietary Antioxidants. April 1, 2014. 3-14.
Source
scopus
Publish Date
2014
Start Page
3
End Page
14
DOI
10.1016/B978-0-12-405205-5.00001-5

Mn porphyrin in combination with ascorbate acts as a pro-oxidant and mediates caspase-independent cancer cell death.

Resistance to therapy-mediated apoptosis in inflammatory breast cancer, an aggressive and distinct subtype of breast cancer, was recently attributed to increased superoxide dismutase (SOD) expression, glutathione (GSH) content, and decreased accumulation of reactive species. In this study, we demonstrate the unique ability of two Mn(III) N-substituted pyridylporphyrin (MnP)-based SOD mimics (MnTE-2-PyP(5+) and MnTnBuOE-2-PyP(5+)) to catalyze oxidation of ascorbate, leading to the production of excessive levels of peroxide, and in turn cell death. The accumulation of peroxide, as a consequence of MnP+ascorbate treatment, was fully reversed by the administration of exogenous catalase, showing that hydrogen peroxide is essential for cell death. Cell death as a consequence of the action of MnP+ascorbate corresponded to decreases in GSH levels, prosurvival signaling (p-NF-κB, p-ERK1/2), and in expression of X-linked inhibitor of apoptosis protein, the most potent caspase inhibitor. Although markers of classical apoptosis were observed, including PARP cleavage and annexin V staining, administration of a pan-caspase inhibitor, Q-VD-OPh, did not reverse the observed cytotoxicity. MnP+ascorbate-treated cells showed nuclear translocation of apoptosis-inducing factor, suggesting the possibility of a mechanism of caspase-independent cell death. Pharmacological ascorbate has already shown promise in recently completed phase I clinical trials, in which its oxidation and subsequent peroxide formation was catalyzed by endogenous metalloproteins. The catalysis of ascorbate oxidation by an optimized metal-based catalyst (such as MnP) carries a large therapeutic potential as an anticancer agent by itself or in combination with other modalities such as radio- and chemotherapy.

Authors
Evans, MK; Tovmasyan, A; Batinic-Haberle, I; Devi, GR
MLA Citation
Evans, MK, Tovmasyan, A, Batinic-Haberle, I, and Devi, GR. "Mn porphyrin in combination with ascorbate acts as a pro-oxidant and mediates caspase-independent cancer cell death." Free Radic Biol Med 68 (March 2014): 302-314.
PMID
24334253
Source
pubmed
Published In
Free Radical Biology and Medicine
Volume
68
Publish Date
2014
Start Page
302
End Page
314
DOI
10.1016/j.freeradbiomed.2013.11.031

A randomized phase II study of immunization with dendritic cells modified with poxvectors encoding CEA and MUC1 compared with the same poxvectors plus GM-CSF for resected metastatic colorectal cancer.

OBJECTIVE: To determine whether 1 of 2 vaccines based on dendritic cells (DCs) and poxvectors encoding CEA (carcinoembryonic antigen) and MUC1 (PANVAC) would lengthen survival in patients with resected metastases of colorectal cancer (CRC). BACKGROUND: Recurrences after complete resections of metastatic CRC remain frequent. Immune responses to CRC are associated with fewer recurrences, suggesting a role for cancer vaccines as adjuvant therapy. Both DCs and poxvectors are potent stimulators of immune responses against cancer antigens. METHODS: Patients, disease-free after CRC metastasectomy and perioperative chemotherapy (n = 74), were randomized to injections of autologous DCs modified with PANVAC (DC/PANVAC) or PANVAC with per injection GM-CSF (granulocyte-macrophage colony-stimulating factor). Endpoints were recurrence-free survival overall survival, and rate of CEA-specific immune responses. Clinical outcome was compared with that of an unvaccinated, contemporary group of patients who had undergone CRC metastasectomy, received similar perioperative therapy, and would have otherwise been eligible for the study. RESULTS: Recurrence-free survival at 2 years was similar (47% and 55% for DC/PANVAC and PANVAC/GM-CSF, respectively) (χ P = 0.48). At a median follow-up of 35.7 months, there were 2 of 37 deaths in the DC/PANVAC arm and 5 of 37 deaths in the PANVAC/GM-CSF arm. The rate and magnitude of T-cell responses against CEA was statistically similar between study arms. As a group, vaccinated patients had superior survival compared with the contemporary unvaccinated group. CONCLUSIONS: Both DC and poxvector vaccines have similar activity. Survival was longer for vaccinated patients than for a contemporary unvaccinated group, suggesting that a randomized trial of poxvector vaccinations compared with standard follow-up after metastasectomy is warranted. (NCT00103142).

Authors
Morse, MA; Niedzwiecki, D; Marshall, JL; Garrett, C; Chang, DZ; Aklilu, M; Crocenzi, TS; Cole, DJ; Dessureault, S; Hobeika, AC; Osada, T; Onaitis, M; Clary, BM; Hsu, D; Devi, GR; Bulusu, A; Annechiarico, RP; Chadaram, V; Clay, TM; Lyerly, HK
MLA Citation
Morse, MA, Niedzwiecki, D, Marshall, JL, Garrett, C, Chang, DZ, Aklilu, M, Crocenzi, TS, Cole, DJ, Dessureault, S, Hobeika, AC, Osada, T, Onaitis, M, Clary, BM, Hsu, D, Devi, GR, Bulusu, A, Annechiarico, RP, Chadaram, V, Clay, TM, and Lyerly, HK. "A randomized phase II study of immunization with dendritic cells modified with poxvectors encoding CEA and MUC1 compared with the same poxvectors plus GM-CSF for resected metastatic colorectal cancer." Ann Surg 258.6 (December 2013): 879-886.
PMID
23657083
Source
pubmed
Published In
Annals of Surgery
Volume
258
Issue
6
Publish Date
2013
Start Page
879
End Page
886
DOI
10.1097/SLA.0b013e318292919e

Quantitative high-throughput efficacy profiling of approved oncology drugs in inflammatory breast cancer models of acquired drug resistance and re-sensitization.

Although there is no standard treatment protocol for inflammatory breast cancer (IBC), multi-modality treatment has improved survival. In this study we profiled the NCI approved oncology drug set in a qHTS format to identify those that are efficacious in basal type and ErbB2 overexpressing IBC models. Further, we characterized the sensitivity of an acquired therapeutic resistance model to the oncology drugs. We observed that lapatinib-induced acquired resistance in SUM149 cells led to cross-resistance to other targeted- and chemotherapeutic drugs. Removal of the primary drug to which the model was developed led to re-sensitization to multiple drugs to a degree comparable to the parental cell line; this coincided with the cells regaining the ability to accumulate ROS and reduced expression of anti-apoptotic factors and the antioxidant SOD2. We suggest that our findings provide a unique IBC model system for gaining an understanding of acquired therapeutic resistance and the effect of redox adaptation on anti-cancer drug efficacy.

Authors
Williams, KP; Allensworth, JL; Ingram, SM; Smith, GR; Aldrich, AJ; Sexton, JZ; Devi, GR
MLA Citation
Williams, KP, Allensworth, JL, Ingram, SM, Smith, GR, Aldrich, AJ, Sexton, JZ, and Devi, GR. "Quantitative high-throughput efficacy profiling of approved oncology drugs in inflammatory breast cancer models of acquired drug resistance and re-sensitization." Cancer Lett 337.1 (August 28, 2013): 77-89.
PMID
23689139
Source
pubmed
Published In
Cancer Letters
Volume
337
Issue
1
Publish Date
2013
Start Page
77
End Page
89
DOI
10.1016/j.canlet.2013.05.017

Novel adenoviral vector induces T-cell responses despite anti-adenoviral neutralizing antibodies in colorectal cancer patients.

First-generation, E1-deleted adenovirus subtype 5 (Ad5)-based vectors, although promising platforms for use as cancer vaccines, are impeded in activity by naturally occurring or induced Ad-specific neutralizing antibodies. Ad5-based vectors with deletions of the E1 and the E2b regions (Ad5 [E1-, E2b-]), the latter encoding the DNA polymerase and the pre-terminal protein, by virtue of diminished late phase viral protein expression, were hypothesized to avoid immunological clearance and induce more potent immune responses against the encoded tumor antigen transgene in Ad-immune hosts. Indeed, multiple homologous immunizations with Ad5 [E1-, E2b-]-CEA(6D), encoding the tumor antigen carcinoembryonic antigen (CEA), induced CEA-specific cell-mediated immune (CMI) responses with antitumor activity in mice despite the presence of preexisting or induced Ad5-neutralizing antibody. In the present phase I/II study, cohorts of patients with advanced colorectal cancer were immunized with escalating doses of Ad5 [E1-, E2b-]-CEA(6D). CEA-specific CMI responses were observed despite the presence of preexisting Ad5 immunity in a majority (61.3 %) of patients. Importantly, there was minimal toxicity, and overall patient survival (48 % at 12 months) was similar regardless of preexisting Ad5 neutralizing antibody titers. The results demonstrate that, in cancer patients, the novel Ad5 [E1-, E2b-] gene delivery platform generates significant CMI responses to the tumor antigen CEA in the setting of both naturally acquired and immunization-induced Ad5-specific immunity.

Authors
Morse, MA; Chaudhry, A; Gabitzsch, ES; Hobeika, AC; Osada, T; Clay, TM; Amalfitano, A; Burnett, BK; Devi, GR; Hsu, DS; Xu, Y; Balcaitis, S; Dua, R; Nguyen, S; Balint, JP; Jones, FR; Lyerly, HK
MLA Citation
Morse, MA, Chaudhry, A, Gabitzsch, ES, Hobeika, AC, Osada, T, Clay, TM, Amalfitano, A, Burnett, BK, Devi, GR, Hsu, DS, Xu, Y, Balcaitis, S, Dua, R, Nguyen, S, Balint, JP, Jones, FR, and Lyerly, HK. "Novel adenoviral vector induces T-cell responses despite anti-adenoviral neutralizing antibodies in colorectal cancer patients." Cancer Immunol Immunother 62.8 (August 2013): 1293-1301.
PMID
23624851
Source
pubmed
Published In
Cancer Immunology, Immunotherapy
Volume
62
Issue
8
Publish Date
2013
Start Page
1293
End Page
1301
DOI
10.1007/s00262-013-1400-3

Abstract 951: Cross-resistance and re-sensitization to multiple drugs in an IBC model of lapatinib acquired resistance parallels redox adaptation.

Authors
Devi, GR; Allensworth, JL; Ingram, SM; Smith, GR; Aldrich, AJ; Williams, KP
MLA Citation
Devi, GR, Allensworth, JL, Ingram, SM, Smith, GR, Aldrich, AJ, and Williams, KP. "Abstract 951: Cross-resistance and re-sensitization to multiple drugs in an IBC model of lapatinib acquired resistance parallels redox adaptation." April 15, 2013.
Source
crossref
Published In
Cancer Research
Volume
73
Issue
8 Supplement
Publish Date
2013
Start Page
951
End Page
951
DOI
10.1158/1538-7445.AM2013-951

Smac mimetic Birinapant induces apoptosis and enhances TRAIL potency in inflammatory breast cancer cells in an IAP-dependent and TNF-α-independent mechanism.

X-linked inhibitor of apoptosis protein (XIAP), the most potent mammalian caspase inhibitor, has been associated with acquired therapeutic resistance in inflammatory breast cancer (IBC), an aggressive subset of breast cancer with an extremely poor survival rate. The second mitochondria-derived activator of caspases (Smac) protein is a potent antagonist of IAP proteins and the basis for the development of Smac mimetic drugs. Here, we report for the first time that bivalent Smac mimetic Birinapant induces cell death as a single agent in TRAIL-insensitive SUM190 (ErbB2-overexpressing) cells and significantly increases potency of TRAIL-induced apoptosis in TRAIL-sensitive SUM149 (triple-negative, EGFR-activated) cells, two patient tumor-derived IBC models. Birinapant has high binding affinity (nM range) for cIAP1/2 and XIAP. Using isogenic SUM149- and SUM190-derived cells with differential XIAP expression (SUM149 wtXIAP, SUM190 shXIAP) and another bivalent Smac mimetic (GT13402) with high cIAP1/2 but low XIAP binding affinity (K (d) > 1 μM), we show that XIAP inhibition is necessary for increasing TRAIL potency. In contrast, single agent efficacy of Birinapant is due to pan-IAP antagonism. Birinapant caused rapid cIAP1 degradation, caspase activation, PARP cleavage, and NF-κB activation. A modest increase in TNF-α production was seen in SUM190 cells following Birinapant treatment, but no increase occurred in SUM149 cells. Exogenous TNF-α addition did not increase Birinapant efficacy. Neutralizing antibodies against TNF-α or TNFR1 knockdown did not reverse cell death. However, pan-caspase inhibitor Q-VD-OPh reversed Birinapant-mediated cell death. In addition, Birinapant in combination or as a single agent decreased colony formation and anchorage-independent growth potential of IBC cells. By demonstrating that Birinapant primes cancer cells for death in an IAP-dependent manner, these findings support the development of Smac mimetics for IBC treatment.

Authors
Allensworth, JL; Sauer, SJ; Lyerly, HK; Morse, MA; Devi, GR
MLA Citation
Allensworth, JL, Sauer, SJ, Lyerly, HK, Morse, MA, and Devi, GR. "Smac mimetic Birinapant induces apoptosis and enhances TRAIL potency in inflammatory breast cancer cells in an IAP-dependent and TNF-α-independent mechanism." Breast Cancer Res Treat 137.2 (January 2013): 359-371.
Website
http://hdl.handle.net/10161/12454
PMID
23225169
Source
pubmed
Published In
Breast Cancer Research and Treatment
Volume
137
Issue
2
Publish Date
2013
Start Page
359
End Page
371
DOI
10.1007/s10549-012-2352-6

Immunologic targeting of FOXP3 in inflammatory breast cancer cells.

The forkhead transcription factor FOXP3 is necessary for induction of regulatory T lymphocytes (Tregs) and their immunosuppressive function. We have previously demonstrated that targeting Tregs by vaccination of mice with murine FOXP3 mRNA-transfected dendritic cells (DCs) elicits FOXP3-specific T cell responses and enhances tumor immunity. It is clear that FOXP3 expression is not restricted to T-cell lineage and herein, using RT-PCR, flow cytometry, and western immunoblot we demonstrate for the first time that FOXP3 is expressed in inflammatory breast cancer (IBC) cells, SUM149 (triple negative, ErbB1-activated) and SUM190 (ErbB2-overexpressing). Importantly, FOXP3-specific T cells generated in vitro using human FOXP3 RNA-transfected DCs as stimulators efficiently lyse SUM149 cells. Interestingly, an isogenic model (rSUM149) derived from SUM149 with an enhanced anti-apoptotic phenotype was resistant to FOXP3-specific T cell mediated lysis. The MHC class I cellular processing mechanism was intact in both cell lines at the protein and transcription levels suggesting that the resistance to cytolysis by rSUM149 cells was not related to MHC class I expression or to the MHC class I antigen processing machinery in these cells. Our data suggest that FOXP3 may be an effective tumor target in IBC cells however increased anti-apoptotic signaling can lead to immune evasion.

Authors
Nair, S; Aldrich, AJ; McDonnell, E; Cheng, Q; Aggarwal, A; Patel, P; Williams, MM; Boczkowski, D; Lyerly, HK; Morse, MA; Devi, GR
MLA Citation
Nair, S, Aldrich, AJ, McDonnell, E, Cheng, Q, Aggarwal, A, Patel, P, Williams, MM, Boczkowski, D, Lyerly, HK, Morse, MA, and Devi, GR. "Immunologic targeting of FOXP3 in inflammatory breast cancer cells." PLoS One 8.1 (2013): e53150-.
PMID
23341929
Source
pubmed
Published In
PloS one
Volume
8
Issue
1
Publish Date
2013
Start Page
e53150
DOI
10.1371/journal.pone.0053150

Co-delivery of antigen and IL-12 by Venezuelan equine encephalitis virus replicon particles enhances antigen-specific immune responses and antitumor effects.

We recently demonstrated that Venezuelan equine encephalitis virus-based replicon particle (VRPs) encoding tumor antigens could break tolerance in the immunomodulatory environment of advanced cancer. We hypothesized that local injection of VRP-expressing interleukin-12 (IL-12) at the site of injections of VRP-based cancer vaccines would enhance the tumor-antigen-specific T cell and antibody responses and antitumor efficacy. Mice were immunized with VRP encoding the human tumor-associated antigen, carcinoembryonic antigen (CEA) (VRP-CEA(6D)), and VRP-IL-12 was also administered at the same site or at a distant location. CEA-specific T cell and antibody responses were measured. To determine antitumor activity, mice were implanted with MC38-CEA-2 cells and immunized with VRP-CEA with and without VRP-IL-12, and tumor growth and mouse survival were measured. VRP-IL-12 greatly enhanced CEA-specific T cell and antibody responses when combined with VRP-CEA(6D) vaccination. VRP-IL-12 was superior to IL-12 protein at enhancing immune responses. Vaccination with VRP-CEA(6D) plus VRP-IL-12 was superior to VRP-CEA(6D) or VRP-IL-12 alone in inducing antitumor activity and prolonging survival in tumor-bearing mice. Importantly, local injection of VRP-IL-12 at the VRP-CEA(6D) injection site provided more potent activation of CEA-specific immune responses than that of VRP-IL-12 injected at a distant site from the VRP-CEA injections. Together, this study shows that VRP-IL-12 enhances vaccination with VRP-CEA(6D) and was more effective at activating CEA-specific T cell responses when locally expressed at the vaccine site. Clinical trials evaluating the adjuvant effect of VRP-IL-12 at enhancing the immunogenicity of cancer vaccines are warranted.

Authors
Osada, T; Berglund, P; Morse, MA; Hubby, B; Lewis, W; Niedzwiecki, D; Yang, XY; Hobeika, A; Burnett, B; Devi, GR; Clay, TM; Smith, J; Kim Lyerly, H
MLA Citation
Osada, T, Berglund, P, Morse, MA, Hubby, B, Lewis, W, Niedzwiecki, D, Yang, XY, Hobeika, A, Burnett, B, Devi, GR, Clay, TM, Smith, J, and Kim Lyerly, H. "Co-delivery of antigen and IL-12 by Venezuelan equine encephalitis virus replicon particles enhances antigen-specific immune responses and antitumor effects." Cancer Immunol Immunother 61.11 (November 2012): 1941-1951.
PMID
22488274
Source
pubmed
Published In
Cancer Immunology, Immunotherapy
Volume
61
Issue
11
Publish Date
2012
Start Page
1941
End Page
1951
DOI
10.1007/s00262-012-1248-y

Smac Mimetic Induces Apoptosis and Synergizes with TRAIL in Inflammatory Breast Cancer Cells in an IAP-Dependent and TNF-a-Independent Mechanism

Authors
Devi, GR; Allensworth, JL; Sauer, SJ; Morse, MM; Lyerly, HK
MLA Citation
Devi, GR, Allensworth, JL, Sauer, SJ, Morse, MM, and Lyerly, HK. "Smac Mimetic Induces Apoptosis and Synergizes with TRAIL in Inflammatory Breast Cancer Cells in an IAP-Dependent and TNF-a-Independent Mechanism." November 2012.
Source
wos-lite
Published In
European Journal of Cancer
Volume
48
Publish Date
2012
Start Page
32
End Page
32

Differential effects of arsenic trioxide on chemosensitization in human hepatic tumor and stellate cell lines.

BACKGROUND: Crosstalk between malignant hepatocytes and the surrounding peritumoral stroma is a key modulator of hepatocarcinogenesis and therapeutic resistance. To examine the chemotherapy resistance of these two cellular compartments in vitro, we evaluated a well-established hepatic tumor cell line, HepG2, and an adult hepatic stellate cell line, LX2. The aim was to compare the chemosensitization potential of arsenic trioxide (ATO) in combination with sorafenib or fluorouracil (5-FU), in both hepatic tumor cells and stromal cells. METHODS: Cytotoxicity of ATO, 5-FU, and sorafenib, alone and in combination against HepG2 cells and LX2 cells was measured by an automated high throughput cell-based proliferation assay. Changes in survival and apoptotic signaling pathways were analyzed by flow cytometry and western blot. Gene expression of the 5-FU metabolic enzyme, thymidylate synthase, was analyzed by real time PCR. RESULTS: Both HepG2 and LX2 cell lines were susceptible to single agent sorafenib and ATO at 24 hr (ATO IC(50): 5.3 μM in LX2; 32.7 μM in HepG2; Sorafenib IC(50): 11.8 μM in LX2; 9.9 μM in HepG2). In contrast, 5-FU cytotoxicity required higher concentrations and prolonged (48-72 hr) drug exposure. Concurrent ATO and 5-FU treatment of HepG2 cells was synergistic, leading to increased cytotoxicity due in part to modulation of thymidylate synthase levels by ATO. Concurrent ATO and sorafenib treatment showed a trend towards increased HepG2 cytotoxicity, possibly due to a significant decrease in MAPK activation in comparison to treatment with ATO alone. CONCLUSIONS: ATO differentially sensitizes hepatic tumor cells and adult hepatic stellate cells to 5-FU and sorafenib. Given the importance of both of these cell types in hepatocarcinogenesis, these data have implications for the rational development of anti-cancer therapy combinations for the treatment of hepatocellular carcinoma (HCC).

Authors
Rangwala, F; Williams, KP; Smith, GR; Thomas, Z; Allensworth, JL; Lyerly, HK; Diehl, AM; Morse, MA; Devi, GR
MLA Citation
Rangwala, F, Williams, KP, Smith, GR, Thomas, Z, Allensworth, JL, Lyerly, HK, Diehl, AM, Morse, MA, and Devi, GR. "Differential effects of arsenic trioxide on chemosensitization in human hepatic tumor and stellate cell lines. (Published online)" BMC Cancer 12 (September 10, 2012): 402-.
PMID
22963400
Source
pubmed
Published In
BMC Cancer
Volume
12
Publish Date
2012
Start Page
402
DOI
10.1186/1471-2407-12-402

XIAP inhibition and generation of reactive oxygen species enhances TRAIL sensitivity in inflammatory breast cancer cells.

We recently identified superoxide dismutase (SOD) overexpression and decreased induction of reactive oxygen species (ROS)-mediated apoptosis in models of inflammatory breast cancer (IBC) cells with acquired therapeutic resistance. This population of cells has high expression of X-linked inhibitor of apoptosis protein (XIAP), which inhibits both extrinsic and intrinsic apoptosis pathways. We therefore wanted to evaluate the effect of classical apoptosis-inducing agent TRAIL, a proapoptotic receptor agonist that selectively triggers death receptor (DR)-mediated apoptosis in cancer cells, in the IBC acquired resistance model. XIAP levels and subsequent inhibition of caspase activity inversely correlated with TRAIL sensitivity in our models of IBC. These include SUM149, a basal-type cell line isolated from primary IBC tumors and isogenic SUM149-derived lines rSUM149 and SUM149 wtXIAP, models of acquired therapeutic resistance with endogenous and exogenous XIAP overexpression, respectively. Inhibition of XIAP function using embelin, a plant-derived cell permeable small molecule, in combination with TRAIL caused a synergistic decrease in cell viability. Embelin treatment resulted in activation of extracellular signal-regulated kinase (ERK)1/2 and ROS accumulation, which correlated with downregulation of antioxidant protein SOD1 and consumption of redox modulator reduced glutathione in the XIAP-overexpressing cells. Simultaneous treatment with an SOD mimic, which protects against ROS accumulation, reversed the decrease in cell viability caused by embelin + TRAIL treatment. Embelin primes IBC cells for TRAIL-mediated apoptosis by its direct action on the anti-caspase activity of XIAP and by shifting the cellular redox balance toward oxidative stress-mediated apoptosis. Thus, ROS modulators represent a novel approach to enhance efficacy of TRAIL-based treatment protocols in IBC.

Authors
Allensworth, JL; Aird, KM; Aldrich, AJ; Batinic-Haberle, I; Devi, GR
MLA Citation
Allensworth, JL, Aird, KM, Aldrich, AJ, Batinic-Haberle, I, and Devi, GR. "XIAP inhibition and generation of reactive oxygen species enhances TRAIL sensitivity in inflammatory breast cancer cells." Mol Cancer Ther 11.7 (July 2012): 1518-1527.
PMID
22508521
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
11
Issue
7
Publish Date
2012
Start Page
1518
End Page
1527
DOI
10.1158/1535-7163.MCT-11-0787

X-linked inhibitor of apoptosis protein-mediated attenuation of apoptosis, using a novel cardiac-enhanced adeno-associated viral vector.

Successful amelioration of cardiac dysfunction and heart failure through gene therapy approaches will require a transgene effective at attenuating myocardial injury, and subsequent remodeling, using an efficient and safe delivery vehicle. Our laboratory has established a well-curated, high-quality repository of human myocardial tissues that we use as a discovery engine to identify putative therapeutic transgene targets, as well as to better understand the molecular basis of human heart failure. By using this rare resource we were able to examine age- and sex-matched left ventricular samples from (1) end-stage failing human hearts and (2) nonfailing human hearts and were able to identify the X-linked inhibitor of apoptosis protein (XIAP) as a novel target for treating cardiac dysfunction. We demonstrate that XIAP is diminished in failing human hearts, indicating that this potent inhibitor of apoptosis may be central in protecting the human heart from cellular injury culminating in heart failure. Efforts to ameliorate heart failure through delivery of XIAP compelled the design of a novel adeno-associated viral (AAV) vector, termed SASTG, that achieves highly efficient transduction in mouse heart and in cultured neonatal rat cardiomyocytes. Increased XIAP expression achieved with the SASTG vector inhibits caspase-3/7 activity in neonatal cardiomyocytes after induction of apoptosis through three common cardiac stresses: protein kinase C-γ inhibition, hypoxia, or β-adrenergic receptor agonist. These studies demonstrate the potential benefit of XIAP to correct heart failure after highly efficient delivery to the heart with the rationally designed SASTG AAV vector.

Authors
Piacentino, V; Milano, CA; Bolanos, M; Schroder, J; Messina, E; Cockrell, AS; Jones, E; Krol, A; Bursac, N; Mao, L; Devi, GR; Samulski, RJ; Bowles, DE
MLA Citation
Piacentino, V, Milano, CA, Bolanos, M, Schroder, J, Messina, E, Cockrell, AS, Jones, E, Krol, A, Bursac, N, Mao, L, Devi, GR, Samulski, RJ, and Bowles, DE. "X-linked inhibitor of apoptosis protein-mediated attenuation of apoptosis, using a novel cardiac-enhanced adeno-associated viral vector." Hum Gene Ther 23.6 (June 2012): 635-646.
PMID
22339372
Source
pubmed
Published In
Human Gene Therapy
Volume
23
Issue
6
Publish Date
2012
Start Page
635
End Page
646
DOI
10.1089/hum.2011.186

ErbB1/2 tyrosine kinase inhibitor mediates oxidative stress-induced apoptosis in inflammatory breast cancer cells.

Overexpression of epidermal growth factor receptors (ErbB) is frequently seen in inflammatory breast cancer (IBC). Treatment with ErbB1/2-targeting agents (lapatinib) mediates tumor apoptosis by downregulating ErbB1/2 phosphorylation and downstream survival signaling. In this study, using carboxy-H(2)DCFDA, DHE, and MitoSOX Red to examine changes in hydrogen peroxide radicals, cytoplasmic and mitochondrial superoxide, respectively, we observed that GW583340 (a lapatinib-analog) increases reactive oxygen species (ROS) in two models of IBC (SUM149, SUM190) that are sensitive to ErbB1/2 blockade. This significant increase in ROS levels was similar to those generated by classical oxidative agents H(2)O(2) and paraquat. In contrast, minimal to basal levels of ROS were measured in a clonal population of GW583340-resistant IBC cells (rSUM149 and rSUM190). The GW583340-resistant IBC cells displayed increased SOD1, SOD2, and glutathione expression, which correlated with decreased sensitivity to the apoptotic-inducing effects of GW583340, H(2)O(2), and paraquat. The ROS increase and cell death in the GW583340-sensitive cells was reversed by simultaneous treatment with a superoxide dismutase (SOD) mimic. Additionally, overcoming the high levels of antioxidants using redox modulators induced apoptosis in the GW583340-resistant cells. Taken together, these data demonstrate a novel mechanism of lapatinib-analog-induced apoptosis and indicate that resistant cells have increased antioxidant potential, which can be overcome by treatment with SOD modulators.

Authors
Aird, KM; Allensworth, JL; Batinic-Haberle, I; Lyerly, HK; Dewhirst, MW; Devi, GR
MLA Citation
Aird, KM, Allensworth, JL, Batinic-Haberle, I, Lyerly, HK, Dewhirst, MW, and Devi, GR. "ErbB1/2 tyrosine kinase inhibitor mediates oxidative stress-induced apoptosis in inflammatory breast cancer cells." Breast Cancer Res Treat 132.1 (February 2012): 109-119.
PMID
21559822
Source
pubmed
Published In
Breast Cancer Research and Treatment
Volume
132
Issue
1
Publish Date
2012
Start Page
109
End Page
119
DOI
10.1007/s10549-011-1568-1

Depleting regulatory T cells with arginine-rich, cell-penetrating, peptide-conjugated morpholino oligomer targeting FOXP3 inhibits regulatory T-cell function.

CD4+CD25+regulatory T cells (T(reg)) impair anti-tumor and anti-viral immunity. As there are higher T(reg) levels in cancer patients compared with healthy individuals, there is considerable interest in eliminating them or altering their function as part of cancer or viral immunotherapy strategies. The scurfin transcriptional regulator encoded by the member of the forkhead winged helix protein family (FOXP3) is critical for maintaining the functions of T(reg). We hypothesized that targeting FOXP3 expression with a novel arginine-rich, cell-penetrating, peptide-conjugated phosphorodiamidate morpholino (PPMO) based antisense would eliminate T(reg) and enhance the induction of effector T-cell responses. We observed that the PPMO was taken up by activated T cells in vitro and could downregulate FOXP3 expression, which otherwise increases during antigen-specific T-cell activation. Generation of antigen-specific T cells in response to peptide stimulation was enhanced by pre-treatment of peripheral blood mononuclear cells with the FOXP3-targeted PPMO. In summary, modulation of T(reg) levels using the FOXP3 PPMO antisense-based genomic strategy has the potential to optimize immunotherapy strategies in cancer and viral immunotherapy.

Authors
Morse, MA; Hobeika, A; Serra, D; Aird, K; McKinney, M; Aldrich, A; Clay, T; Mourich, D; Lyerly, HK; Iversen, PL; Devi, GR
MLA Citation
Morse, MA, Hobeika, A, Serra, D, Aird, K, McKinney, M, Aldrich, A, Clay, T, Mourich, D, Lyerly, HK, Iversen, PL, and Devi, GR. "Depleting regulatory T cells with arginine-rich, cell-penetrating, peptide-conjugated morpholino oligomer targeting FOXP3 inhibits regulatory T-cell function." Cancer Gene Ther 19.1 (January 2012): 30-37.
PMID
21997230
Source
pubmed
Published In
Cancer Gene Therapy
Volume
19
Issue
1
Publish Date
2012
Start Page
30
End Page
37
DOI
10.1038/cgt.2011.63

Cytotoxic effects of Mn(III) N-alkylpyridylporphyrins in the presence of cellular reductant, ascorbate.

Due to the ability to easily accept and donate electrons Mn(III)N-alkylpyridylporphyrins (MnPs) can dismute O(2)(·-), reduce peroxynitrite, but also generate reactive species and behave as pro-oxidants if conditions favour such action. Herein two ortho isomers, MnTE-2-PyP(5+), MnTnHex-2-PyP(5+), and a meta isomer MnTnHex-3-PyP(5+), which differ greatly with regard to their metal-centered reduction potential, E(1/2) (Mn(III)P/Mn(II)P) and lipophilicity, were explored. Employing Mn(III)P/Mn(II)P redox system for coupling with ascorbate, these MnPs catalyze ascorbate oxidation and thus peroxide production. Consequently, cancer oxidative burden may be enhanced, which in turn would suppress its growth. Cytotoxic effects on Caco-2, Hela, 4T1, HCT116 and SUM149 were studied. When combined with ascorbate, MnPs killed cancer cells via peroxide produced outside of the cell. MnTE-2-PyP(5+) was the most efficacious catalyst for peroxide production, while MnTnHex-3-PyP(5+) is most prone to oxidative degradation with H(2) , and thus the least efficacious. A 4T1 breast cancer mouse study of limited scope and success was conducted. The tumour oxidative stress was enhanced and its microvessel density reduced when mice were treated either with ascorbate or MnP/ascorbate; the trend towards tumour growth suppression was detected.

Authors
Ye, X; Fels, D; Tovmasyan, A; Aird, KM; Dedeugd, C; Allensworth, JL; Kos, I; Park, W; Spasojevic, I; Devi, GR; Dewhirst, MW; Leong, KW; Batinic-Haberle, I
MLA Citation
Ye, X, Fels, D, Tovmasyan, A, Aird, KM, Dedeugd, C, Allensworth, JL, Kos, I, Park, W, Spasojevic, I, Devi, GR, Dewhirst, MW, Leong, KW, and Batinic-Haberle, I. "Cytotoxic effects of Mn(III) N-alkylpyridylporphyrins in the presence of cellular reductant, ascorbate." Free Radic Res 45.11-12 (November 2011): 1289-1306.
PMID
21859376
Source
pubmed
Published In
Free Radical Research (Informa)
Volume
45
Issue
11-12
Publish Date
2011
Start Page
1289
End Page
1306
DOI
10.3109/10715762.2011.616199

Targeting GLI1 expression in human inflammatory breast cancer cells enhances apoptosis and attenuates migration.

BACKGROUND: Inflammatory breast cancer (IBC) is an aggressive subtype of breast cancer with distinct molecular profiles. Gene expression profiling previously identified sonic hedgehog (SHH) as part of a gene signature that is differentially regulated in IBC patients. METHODS: The effects of reducing GLI1 levels on protein expression, cell proliferation, apoptosis and migration were determined by immunoblots, MTT assay, Annexin-V/PI assay and conventional and automated cell migration assays. RESULTS: Evaluation of a panel of breast cancer cell lines revealed elevated GLI1 expression, typically a marker for hedgehog-pathway activation, in a triple-negative, highly invasive IBC cell line, SUM149 and its isogenic-derived counterpart rSUM149 that has acquired resistance to ErbB1/2 targeting strategies. Downregulation of GLI1 expression in SUM149 and rSUM149 by small interfering RNA or a small molecule GLI1 inhibitor resulted in decreased proliferation and increased apoptosis. Further, GLI1 suppression in these cell lines significantly inhibited cell migration as assessed by a wound-healing assay compared with MCF-7, a non-invasive cell line with low GLI1 expression. A novel high-content migration assay allowed us to quantify multiple effects of GLI1 silencing including significant decreases in cell distance travelled and linearity of movement. CONCLUSION: Our data reveal a role for GLI1 in IBC cell proliferation, survival and migration, which supports the feasibility of targeting GLI1 as a novel therapeutic strategy for IBC patients.

Authors
Thomas, ZI; Gibson, W; Sexton, JZ; Aird, KM; Ingram, SM; Aldrich, A; Lyerly, HK; Devi, GR; Williams, KP
MLA Citation
Thomas, ZI, Gibson, W, Sexton, JZ, Aird, KM, Ingram, SM, Aldrich, A, Lyerly, HK, Devi, GR, and Williams, KP. "Targeting GLI1 expression in human inflammatory breast cancer cells enhances apoptosis and attenuates migration." Br J Cancer 104.10 (May 10, 2011): 1575-1586.
PMID
21505458
Source
pubmed
Published In
British Journal of Cancer
Volume
104
Issue
10
Publish Date
2011
Start Page
1575
End Page
1586
DOI
10.1038/bjc.2011.133

Polyclonal immune responses to antigens associated with cancer signaling pathways and new strategies to enhance cancer vaccines.

Aberrant signaling pathways are a hallmark of cancer. A variety of strategies for inhibiting signaling pathways have been developed, but monoclonal antibodies against receptor tyrosine kinases have been among the most successful. A challenge for these therapies is therapeutic unresponsiveness and acquired resistance due to mutations in the receptors, upregulation of alternate growth and survival pathways, or inadequate function of the monoclonal antibodies. Vaccines are able to induce polyclonal responses that can have a multitude of affects against the target molecule. We began to explore therapeutic vaccine development to antigens associated with these signaling pathways. We provide an illustrative example in developing therapeutic cancer vaccines inducing polyclonal adaptive immune responses targeting the ErbB family member HER2. Further, we will discuss new strategies to augment the clinical efficacy of cancer vaccines by enhancing vaccine immunogenicity and reversing the immunosuppressive tumor microenvironment.

Authors
Clay, TM; Osada, T; Hartman, ZC; Hobeika, A; Devi, G; Morse, MA; Lyerly, HK
MLA Citation
Clay, TM, Osada, T, Hartman, ZC, Hobeika, A, Devi, G, Morse, MA, and Lyerly, HK. "Polyclonal immune responses to antigens associated with cancer signaling pathways and new strategies to enhance cancer vaccines." Immunol Res 49.1-3 (April 2011): 235-247.
PMID
21136201
Source
pubmed
Published In
Immunologic Research
Volume
49
Issue
1-3
Publish Date
2011
Start Page
235
End Page
247
DOI
10.1007/s12026-010-8186-6

Low-dose fractionated radiation potentiates the effects of cisplatin independent of the hyper-radiation sensitivity in human lung cancer cells.

In this study, the role of hyper-radiation sensitivity (HRS) in potentiating the effects of cisplatin by low-dose fractionated radiation (LDFRT) was evaluated in four human non-small cell lung cancer cell lines. Presence of HRS and cisplatin enhancement ratio (CER) by LDFRT/2 Gy was assessed using colony-forming and apoptotic assays. Cell-cycle disturbances were studied by flow cytometry. Expression of genes involved in apoptosis was assessed using real-time reverse transcriptase PCR arrays. H-157 cells showed a distinct HRS region, followed by UKY-29 and A549 cells, whereas it was absent in H460 cells, which when lack HRS showed maximum CER with LDFRT (4 × 0.5 Gy) both by clonogenic inhibition and by apoptosis compared with single fraction of 2 Gy whereas the most radioresistant A549 cells had the least CER, with no significant differences between LDFRT or 2 Gy. Interestingly, in H-157 cells, a more pronounced CER was observed with LDFRT when assessed by apoptosis but clonogenic inhibition-CER was higher with 2 Gy than with LDFRT. Excluding H-157 cells, the CER by LDFRT was inversely proportional to radioresistance [(determined by D(0), the dose to reduce survival by 67% from any point on the linear portion of the survival curve or surviving fraction (SF) at 2 Gy (SF(2))] of the cells. LDFRT alone or in combination with cisplatin induced larger number of proapoptotic genes than 2 Gy or cisplatin + 2 Gy in cells showing HRS when compared to H460 cells that lack HRS. These findings indicate that chemopotentiation by LDFRT is correlated more with the intrinsic radiation sensitivity of the non-small lung cancer cells than the HRS phenomenon whereas the mode of cell killing is both through apoptosis and clonogenic inhibition.

Authors
Gupta, S; Koru-Sengul, T; Arnold, SM; Devi, GR; Mohiuddin, M; Ahmed, MM
MLA Citation
Gupta, S, Koru-Sengul, T, Arnold, SM, Devi, GR, Mohiuddin, M, and Ahmed, MM. "Low-dose fractionated radiation potentiates the effects of cisplatin independent of the hyper-radiation sensitivity in human lung cancer cells." Mol Cancer Ther 10.2 (February 2011): 292-302.
PMID
21216938
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
10
Issue
2
Publish Date
2011
Start Page
292
End Page
302
DOI
10.1158/1535-7163.MCT-10-0630

Abstract P1-04-01: X-Linked Inhibitor of Apoptosis Protein (XIAP) Regulates TRAIL-Induced Apoptosis in Inflammatory Breast Cancer Cells

Authors
Allensworth, JL; Aird, KM; Murray, MB; Devi, GR
MLA Citation
Allensworth, JL, Aird, KM, Murray, MB, and Devi, GR. "Abstract P1-04-01: X-Linked Inhibitor of Apoptosis Protein (XIAP) Regulates TRAIL-Induced Apoptosis in Inflammatory Breast Cancer Cells." Cancer Research 70.24 Supplement (December 15, 2010): P1-04-01-P1-04-01.
Source
crossref
Published In
Cancer Research
Volume
70
Issue
24 Supplement
Publish Date
2010
Start Page
P1-04-01
End Page
P1-04-01
DOI
10.1158/0008-5472.SABCS10-P1-04-01

An alphavirus vector overcomes the presence of neutralizing antibodies and elevated numbers of Tregs to induce immune responses in humans with advanced cancer.

Therapeutic anticancer vaccines are designed to boost patients' immune responses to tumors. One approach is to use a viral vector to deliver antigen to in situ DCs, which then activate tumor-specific T cell and antibody responses. However, vector-specific neutralizing antibodies and suppressive cell populations such as Tregs remain great challenges to the efficacy of this approach. We report here that an alphavirus vector, packaged in virus-like replicon particles (VRP) and capable of efficiently infecting DCs, could be repeatedly administered to patients with metastatic cancer expressing the tumor antigen carcinoembryonic antigen (CEA) and that it overcame high titers of neutralizing antibodies and elevated Treg levels to induce clinically relevant CEA-specific T cell and antibody responses. The CEA-specific antibodies mediated antibody-dependent cellular cytotoxicity against tumor cells from human colorectal cancer metastases. In addition, patients with CEA-specific T cell responses exhibited longer overall survival. These data suggest that VRP-based vectors can overcome the presence of neutralizing antibodies to break tolerance to self antigen and may be clinically useful for immunotherapy in the setting of tumor-induced immunosuppression.

Authors
Morse, MA; Hobeika, AC; Osada, T; Berglund, P; Hubby, B; Negri, S; Niedzwiecki, D; Devi, GR; Burnett, BK; Clay, TM; Smith, J; Lyerly, HK
MLA Citation
Morse, MA, Hobeika, AC, Osada, T, Berglund, P, Hubby, B, Negri, S, Niedzwiecki, D, Devi, GR, Burnett, BK, Clay, TM, Smith, J, and Lyerly, HK. "An alphavirus vector overcomes the presence of neutralizing antibodies and elevated numbers of Tregs to induce immune responses in humans with advanced cancer." J Clin Invest 120.9 (September 2010): 3234-3241.
Website
http://hdl.handle.net/10161/4330
PMID
20679728
Source
pubmed
Published In
Journal of Clinical Investigation
Volume
120
Issue
9
Publish Date
2010
Start Page
3234
End Page
3241
DOI
10.1172/JCI42672

Synergism from combined immunologic and pharmacologic inhibition of HER2 in vivo.

The monoclonal antibody trastuzumab and the EGFR/HER2 tyrosine kinase inhibitor lapatinib improve the clinical outcome of patients with HER2-overexpressing breast cancer. However, the majority of metastatic cancers will eventually progress, suggesting the need for other therapies. Because HER2 overexpression persists, we hypothesized that the anti-HER2 immune response induced by cancer vaccines would be an effective strategy for treating trastuzumab- and lapatinib-refractory tumors. Furthermore, we hypothesized that the antibody response could synergize with lapatinib to enhance tumor inhibition. We developed a recombinant adenoviral vector expressing a kinase-inactive HER2 (Ad-HER2-ki) to use as a cancer vaccine. Vaccine-induced polyclonal HER2-specific antiserum was analyzed for receptor internalization and signaling effects alone and in combination with lapatinib. Ad-HER2-ki vaccine-induced potent T cell and antibody responses in mice and the vaccine-induced polyclonal HER2-specific antiserum mediated receptor internalization and degradation much more effectively than trastuzumab. Our in vitro studies demonstrated that HER2 vaccine-induced antibodies effectively caused a decrease in HER2 expression, but when combined with lapatinib caused significant inhibition of HER2 signaling, decreased pERK and pAKT levels and reduced breast tumor cell proliferation. In addition, a known mechanism of resistance to lapatinib, induction of survivin, was inhibited. The combination of Ad-HER2-ki plus lapatinib also showed superior antitumor efficacy in vivo. Based on these results, we feel clinical studies using this approach to target HER2-overexpressing breast cancer, including trastuzumab- and lapatinib-resistant tumors is warranted.

Authors
Morse, MA; Wei, J; Hartman, Z; Xia, W; Ren, X-R; Lei, G; Barry, WT; Osada, T; Hobeika, AC; Peplinski, S; Jiang, H; Devi, GR; Chen, W; Spector, N; Amalfitano, A; Lyerly, HK; Clay, TM
MLA Citation
Morse, MA, Wei, J, Hartman, Z, Xia, W, Ren, X-R, Lei, G, Barry, WT, Osada, T, Hobeika, AC, Peplinski, S, Jiang, H, Devi, GR, Chen, W, Spector, N, Amalfitano, A, Lyerly, HK, and Clay, TM. "Synergism from combined immunologic and pharmacologic inhibition of HER2 in vivo." Int J Cancer 126.12 (June 15, 2010): 2893-2903.
PMID
19856307
Source
pubmed
Published In
International Journal of Cancer
Volume
126
Issue
12
Publish Date
2010
Start Page
2893
End Page
2903
DOI
10.1002/ijc.24995

X-linked inhibitor of apoptosis protein inhibits apoptosis in inflammatory breast cancer cells with acquired resistance to an ErbB1/2 tyrosine kinase inhibitor.

Inflammatory breast cancer (IBC) is a highly aggressive subtype of breast cancer that is often characterized by ErbB2 overexpression. ErbB2 targeting is clinically relevant using trastuzumab (anti-ErbB2 antibody) and lapatinib (small-molecule ErbB1/2 inhibitor). However, acquired resistance is a common outcome even in IBC patients who show an initial clinical response, which limits the efficacy of these agents. In the present study, using a clonal population of GW583340 (lapatinib analogue, ErbB1/2 inhibitor)-resistant IBC cells, we identified the overexpression of an antiapoptotic protein, X-linked inhibitor of apoptosis protein (XIAP), in acquired resistance to GW583340 in both ErbB2-overexpressing SUM190 and ErbB1-activated SUM149 cell lines derived from primary IBC tumors. A marked decrease in p-ErbB2, p-ErbB1, and downstream signaling was evident in the GW583340-resistant cells (rSUM190 and rSUM149) similar to parental counterparts treated with the drug, suggesting that the primary mechanism of action of GW583340 was not compromised in resistant cells. However, rSUM190 and rSUM149 cells growing in GW583340 had significant XIAP overexpression and resistance to GW583340-mediated apoptosis. Additionally, stable XIAP overexpression using a lentiviral system reversed sensitivity to GW583340 in parental cells. The observed overexpression was identified to be caused by IRES-mediated XIAP translation. XIAP downregulation in rSUM190 and rSUM149 cells using a small-molecule inhibitor (embelin), which abrogates the XIAP/procaspase-9 interaction, resulted in decreased viability, showing that XIAP is required for survival of cells with acquired resistance to GW583340. These studies establish the feasibility of development of an XIAP inhibitor that potentiates apoptosis for use in IBC patients with resistance to ErbB2-targeting agents.

Authors
Aird, KM; Ghanayem, RB; Peplinski, S; Lyerly, HK; Devi, GR
MLA Citation
Aird, KM, Ghanayem, RB, Peplinski, S, Lyerly, HK, and Devi, GR. "X-linked inhibitor of apoptosis protein inhibits apoptosis in inflammatory breast cancer cells with acquired resistance to an ErbB1/2 tyrosine kinase inhibitor." Mol Cancer Ther 9.5 (May 2010): 1432-1442.
PMID
20406946
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
9
Issue
5
Publish Date
2010
Start Page
1432
End Page
1442
DOI
10.1158/1535-7163.MCT-10-0160

An adenoviral vaccine encoding full-length inactivated human Her2 exhibits potent immunogenicty and enhanced therapeutic efficacy without oncogenicity.

PURPOSE: Overexpression of the breast cancer oncogene HER2 correlates with poor survival. Current HER2-directed therapies confer limited clinical benefits and most patients experience progressive disease. Because refractory tumors remain strongly HER2+, vaccine approaches targeting HER2 have therapeutic potential, but wild type (wt) HER2 cannot safely be delivered in immunogenic viral vectors because it is a potent oncogene. We designed and tested several HER2 vaccines devoid of oncogenic activity to develop a safe vaccine for clinical use. EXPERIMENTAL DESIGN: We created recombinant adenoviral vectors expressing the extracellular domain of HER2 (Ad-HER2-ECD), ECD plus the transmembrane domain (Ad-HER2-ECD-TM), and full-length HER2 inactivated for kinase function (Ad-HER2-ki), and determined their immunogenicity and antitumor effect in wild type (WT) and HER2-tolerant mice. To assess their safety, we compared their effect on the cellular transcriptome, cell proliferation, anchorage-dependent growth, and transformation potential in vivo. RESULTS: Ad-HER2-ki was the most immunogenic vector in WT animals, retained immunogenicity in HER2-transgenic tolerant animals, and showed strong therapeutic efficacy in treatment models. Despite being highly expressed, HER2-ki protein was not phosphorylated and did not produce an oncogenic gene signature in primary human cells. Moreover, in contrast to HER2-wt, cells overexpressing HER2-ki were less proliferative, displayed less anchorage-independent growth, and were not transformed in vivo. CONCLUSIONS: Vaccination with mutationally inactivated, nononcogenic Ad-HER2-ki results in robust polyclonal immune responses to HER2 in tolerant models, which translates into strong and effective antitumor responses in vivo. Ad-HER2-ki is thus a safe and promising vaccine for evaluation in clinical trials.

Authors
Hartman, ZC; Wei, J; Osada, T; Glass, O; Lei, G; Yang, X-Y; Peplinski, S; Kim, D-W; Xia, W; Spector, N; Marks, J; Barry, W; Hobeika, A; Devi, G; Amalfitano, A; Morse, MA; Lyerly, HK; Clay, TM
MLA Citation
Hartman, ZC, Wei, J, Osada, T, Glass, O, Lei, G, Yang, X-Y, Peplinski, S, Kim, D-W, Xia, W, Spector, N, Marks, J, Barry, W, Hobeika, A, Devi, G, Amalfitano, A, Morse, MA, Lyerly, HK, and Clay, TM. "An adenoviral vaccine encoding full-length inactivated human Her2 exhibits potent immunogenicty and enhanced therapeutic efficacy without oncogenicity." Clin Cancer Res 16.5 (March 1, 2010): 1466-1477.
PMID
20179231
Source
pubmed
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
16
Issue
5
Publish Date
2010
Start Page
1466
End Page
1477
DOI
10.1158/1078-0432.CCR-09-2549

Metastatic colorectal cancer cells from patients previously treated with chemotherapy are sensitive to T-cell killing mediated by CEA/CD3-bispecific T-cell-engaging BiTE antibody.

BACKGROUND: Novel technologies to redirect T-cell killing against cancer cells are emerging. We hypothesised that metastatic human colorectal cancer (CRC) previously treated with conventional chemotherapy would be sensitive to T-cell killing mediated by carcinoembryonic antigen (CEA)/CD3-bispecific T-cell-engaging BiTE antibody (MEDI-565). METHODS: We analysed proliferation and lysis of CEA-positive (CEA+) CRC specimens that had survived previous systemic chemotherapy and biologic therapy to determine whether they could be killed by patient T cells engaged by MEDI-565 in vitro. RESULTS: At low concentrations (0.1-1 ng ml(-1)), MEDI-565+ T cells caused reduced proliferation and enhanced apoptosis of CEA+ human CRC specimens. High levels of soluble CEA did not impair killing by redirected T cells and there was no increase in resistance to T-cell killing despite multiple rounds of exposure. CONCLUSIONS: This study shows for the first time that metastatic CRC specimens derived from patients previously treated with conventional chemotherapy can be lysed by patient T cells. Clinical testing of cancer immunotherapies, such as MEDI-565 that result in exposure of tumours to large numbers of T cells, is warranted.

Authors
Osada, T; Hsu, D; Hammond, S; Hobeika, A; Devi, G; Clay, TM; Lyerly, HK; Morse, MA
MLA Citation
Osada, T, Hsu, D, Hammond, S, Hobeika, A, Devi, G, Clay, TM, Lyerly, HK, and Morse, MA. "Metastatic colorectal cancer cells from patients previously treated with chemotherapy are sensitive to T-cell killing mediated by CEA/CD3-bispecific T-cell-engaging BiTE antibody." Br J Cancer 102.1 (January 5, 2010): 124-133.
PMID
19953093
Source
pubmed
Published In
British Journal of Cancer
Volume
102
Issue
1
Publish Date
2010
Start Page
124
End Page
133
DOI
10.1038/sj.bjc.6605364

Cellular uptake of neutral phosphorodiamidate morpholino oligomers.

Phosphorodiamidate morpholino oligomers (PMO), which have a neutral chemistry, are extensively being used as tools for selective inhibition of gene expression in cell culture models and are currently in human clinical trials. Unlike phosphorothioates (PS ODN) and other charged oligonucleotides, little is known about the uptake characteristics of neutral oligomers. The purpose of this study was to understand the kinetics of PMO transport in cells and correlate with antisense activity. In contrast to primary cells and some transformed cell lines which were uptake permissive, established cancer cell lines showed very poor uptake with an occasional diffuse intracellular pattern. Differential PMO uptake was also observed in immune cells, with dendritic cells and monocytes showing highest uptake compared to T and B cells. In addition, PMO localization was observed to be heterogeneous within a population of uptake permissive cells. Unassisted PMO delivery targeting specific genes was correlated with functional antisense efficacy in experiments showing correction of pre-mRNA missplicing and inhibition of target enzyme activity in cells in culture. PMO internalization in uptake-permissive cells was identified to be specific, saturable, and energy-dependent, suggesting a receptor mediated uptake mechanism. Understanding PMO transport should facilitate the design of more effective synthetic antisense oligomers as therapeutic agents.

Authors
Iversen, PL; Aird, KM; Wu, R; Morse, MM; Devi, GR
MLA Citation
Iversen, PL, Aird, KM, Wu, R, Morse, MM, and Devi, GR. "Cellular uptake of neutral phosphorodiamidate morpholino oligomers." Curr Pharm Biotechnol 10.6 (September 2009): 579-588.
PMID
19619124
Source
pubmed
Published In
Current Pharmaceutical Biotechnology
Volume
10
Issue
6
Publish Date
2009
Start Page
579
End Page
588

MLH1 expression sensitises ovarian cancer cells to cell death mediated by XIAP inhibition.

BACKGROUND: The X-linked inhibitor of apoptosis protein (XIAP), an endogenous apoptosis suppressor, can determine the level of caspase accumulation and the resultant response to apoptosis-inducing agents such as cisplatin in epithelial ovarian cancer (EOC). In addition, the mismatch repair protein, hMLH1, has been linked to DNA damage-induced apoptosis by cisplatin by both p53-dependent and -independent mechanisms. METHODS: In this study, hMLH1 expression was correlated with clinical response to platinum drugs and survival in advanced stage (III-IV) EOC patients. We then investigated whether MLH1 loss was a determinant in anti-apoptosis response to cisplatin mediated by XIAP in isogenic and established EOC cell lines with differential p53 status. RESULTS: The percentage of cells undergoing cisplatin-induced cell killing was higher in MLH1-proficient cells than in MLH1-defective cells. In addition, the presence of wild-type hMLH1 or hMLH1 re-expression significantly increased sensitivity to 6-thioguanine, a MMR-dependent agent. Cell-death response to 6-thioguanine and cisplatin was associated with significant proteolysis of MLH1, with XIAP destabilisation and increased caspase-3 activity. The siRNA-mediated inhibition of XIAP increased MLH1 proteolysis and cell death in MLH1-proficient cells but not in MLH1-defective cells. CONCLUSION: These data suggest that XIAP inhibitors may prove to be an effective means of sensitising EOC to MLH1-dependent apoptosis.

Authors
Ding, X; Mohd, AB; Huang, Z; Baba, T; Bernardini, MQ; Lyerly, HK; Berchuck, A; Murphy, SK; Buermeyer, AB; Devi, GR
MLA Citation
Ding, X, Mohd, AB, Huang, Z, Baba, T, Bernardini, MQ, Lyerly, HK, Berchuck, A, Murphy, SK, Buermeyer, AB, and Devi, GR. "MLH1 expression sensitises ovarian cancer cells to cell death mediated by XIAP inhibition." Br J Cancer 101.2 (July 21, 2009): 269-277.
PMID
19603033
Source
pubmed
Published In
British Journal of Cancer
Volume
101
Issue
2
Publish Date
2009
Start Page
269
End Page
277
DOI
10.1038/sj.bjc.6605180

The effects of varying dietary carbohydrate and fat content on survival in a murine LNCaP prostate cancer xenograft model.

PURPOSE: Numerous dietary factors elevate serum levels of insulin and insulin-like growth factor I (IGF-I), both potent prostate cancer mitogens. We tested whether varying dietary carbohydrate and fat, without energy restriction relative to comparison diets, would slow tumor growth and reduce serum insulin, IGF-I, and other molecular mediators of prostate cancer in a xenograft model. EXPERIMENTAL DESIGN: Individually caged male severe combined immunodeficient mice (n = 130) were randomly assigned to one of three diets (described as percent total calories): very high-fat/no-carbohydrate ketogenic diet (NCKD: 83% fat, 0% carbohydrate, 17% protein), low-fat/high-carbohydrate diet (LFD: 12% fat, 71% carbohydrate, 17% protein), or high-fat/moderate-carbohydrate diet (MCD: 40% fat, 43% carbohydrate, 17% protein). Mice were fed to maintain similar average body weights among groups. Following a preliminary feeding period, mice were injected with 1 x 10(6) LNCaP cells (day 0) and sacrificed when tumors were >or=1,000 mm(3). RESULTS: Two days before tumor injection, median NCKD body weight was 2.4 g (10%) and 2.1 g (8%) greater than the LFD and MCD groups, respectively (P < 0.0001). Diet was significantly associated with overall survival (log-rank P = 0.004). Relative to MCD, survival was significantly prolonged for the LFD (hazard ratio, 0.49; 95% confidence interval, 0.29-0.79; P = 0.004) and NCKD groups (hazard ratio, 0.59; 95% confidence interval, 0.37-0.93; P = 0.02). Median serum insulin, IGF-I, IGF-I/IGF binding protein-1 ratio, and IGF-I/IGF binding protein-3 ratio were significantly reduced in NCKD relative to MCD mice. Phospho-AKT/total AKT ratio and pathways associated with antiapoptosis, inflammation, insulin resistance, and obesity were also significantly reduced in NCKD relative to MCD tumors. CONCLUSIONS: These results support further preclinical exploration of carbohydrate restriction in prostate cancer and possibly warrant pilot or feasibility testing in humans.

Authors
Mavropoulos, JC; Buschemeyer, WC; Tewari, AK; Rokhfeld, D; Pollak, M; Zhao, Y; Febbo, PG; Cohen, P; Hwang, D; Devi, G; Demark-Wahnefried, W; Westman, EC; Peterson, BL; Pizzo, SV; Freedland, SJ
MLA Citation
Mavropoulos, JC, Buschemeyer, WC, Tewari, AK, Rokhfeld, D, Pollak, M, Zhao, Y, Febbo, PG, Cohen, P, Hwang, D, Devi, G, Demark-Wahnefried, W, Westman, EC, Peterson, BL, Pizzo, SV, and Freedland, SJ. "The effects of varying dietary carbohydrate and fat content on survival in a murine LNCaP prostate cancer xenograft model." Cancer Prev Res (Phila) 2.6 (June 2009): 557-565.
PMID
19470786
Source
pubmed
Published In
Cancer Prevention Research
Volume
2
Issue
6
Publish Date
2009
Start Page
557
End Page
565
DOI
10.1158/1940-6207.CAPR-08-0188

Delivery of phosphorodiamidate morpholino antisense oligomers in cancer cells.

Phosphorodiamidate morpholino oligomers (PMO), which have a neutral chemistry, are extensively being used as tools for selective inhibition of gene expression in cell culture models and are currently in human clinical trials. PMO oligomers possess a unique structure, in which the deoxyribose moiety of DNA is replaced with a six-membered morpholine ring and the charged phosphodiester internucleoside linkages are replaced with neutral phosphorodiamidate linkages. PMO internalization in uptake-permissive cells has been observed to be specific, saturable, and energy-dependent, suggesting a receptor-mediated uptake mechanism. Understanding PMO transport should facilitate the design of more effective synthetic antisense oligomers as therapeutic agents.

Authors
Devi, GR
MLA Citation
Devi, GR. "Delivery of phosphorodiamidate morpholino antisense oligomers in cancer cells." Methods Mol Biol 542 (2009): 351-361.
PMID
19565912
Source
pubmed
Published In
Methods in molecular biology (Clifton, N.J.)
Volume
542
Publish Date
2009
Start Page
351
End Page
361
DOI
10.1007/978-1-59745-561-9_19

Immune Cells and the Tumor Microenvironment

Authors
Hsu, DS; Morse, M; Clay, T; Devi, G; Lyerly, HK
MLA Citation
Hsu, DS, Morse, M, Clay, T, Devi, G, and Lyerly, HK. "Immune Cells and the Tumor Microenvironment." 2009. 818-829.
Source
scival
Publish Date
2009
Start Page
818
End Page
829
DOI
10.1016/B978-0-12-369420-1.00068-8

c-MYC antisense phosphosphorodiamidate morpholino oligomer inhibits lung metastasis in a murine tumor model.

BACKGROUND: c-MYC amplification and overexpression has been correlated with progression and chemotherapy resistance in lung cancer. AVI-4126, a neutral antisense phosphorodiamidate morpholino oligomer (PMO) has been identified to specifically inhibit c-MYC expression in multiple disease models and identified in Phase I clinical studies to be safe and bioavailable in solid tumors. The present study evaluates AVI-4126 on the development of lung metastasis in the LLC1 syngeneic murine tumor model. Further, this is the first study to show in vivo mis-splicing of c-MYC post-AVI-4126 treatment. METHODS AND RESULTS: Subcutaneous administration of AVI-4126 at local tumor site (50 microg/day) for 3 cycles of 5 days a week starting day 1 post-tumor cell implantation showed significantly decreased tumor burden, number of tumorlets formed in the lung in comparison to saline or control PMO treatment groups, although no significant reduction of the subcutaneous tumor was observed. AVI-4126 treated lung had markedly reduced mitotic activity but higher rate of apoptosis compared to the controls. HPLC-based analysis of tumor and lung lysates confirmed the presence of intact PMO. In addition to decrease in c-MYC expression, a moderate reduction in the levels of MMP-9 mRNA, a pro-angiogenic extracellular matrix protein postulated to be involved in extravasation of cells from the localized tumor or implantation into the distant metastatic site was observed in the LLC1 tumor tissue of AVI-4126 treated animals. CONCLUSIONS: The study results are significant in the development of novel anti-tumoral therapeutic strategies directed to c-MYC-overexpressing tumors and establish AVI-4126 as a strong clinical candidate for metastatic disease.

Authors
Sekhon, HS; London, CA; Sekhon, M; Iversen, PL; Devi, GR
MLA Citation
Sekhon, HS, London, CA, Sekhon, M, Iversen, PL, and Devi, GR. "c-MYC antisense phosphosphorodiamidate morpholino oligomer inhibits lung metastasis in a murine tumor model." Lung Cancer 60.3 (June 2008): 347-354.
PMID
18096271
Source
pubmed
Published In
Lung Cancer
Volume
60
Issue
3
Publish Date
2008
Start Page
347
End Page
354
DOI
10.1016/j.lungcan.2007.10.028

Trastuzumab signaling in ErbB2-overexpressing inflammatory breast cancer correlates with X-linked inhibitor of apoptosis protein expression.

Inflammatory breast cancer (IBC) patients show poor survival and a significant incidence of epidermal growth factor receptor-2 (ErbB2) overexpression. A distinct mechanism involving increased expression of X-linked inhibitor of apoptosis protein (XIAP) and survivin, key members of the inhibitor of apoptosis protein (IAP) family, was observed post-trastuzumab (an ErbB2 monoclonal antibody) treatment in an ErbB2-overexpressing, estrogen receptor negative, IBC cellular model, SUM190PT, isolated from a primary IBC tumor. In contrast, a decrease in the IAP expression was observed in the non-IBC, ErbB2-overexpressing SKBR3 cells in which trastuzumab treatment also decreased p-AKT and cell viability. Further, in SUM190PT cells, therapeutic sensitivity to GW583340 (a dual epidermal growth factor receptor/ErbB2 kinase inhibitor) corresponded with XIAP down-regulation and abrogation of XIAP inhibition on active caspase-9 release. Specific small interfering RNA-mediated XIAP inhibition in combination with trastuzumab caused decrease in inactive procaspase-9 and inhibition of p-AKT corresponding with 45% to 50% decrease in cell viability in the SUM190PT cells, which have high steady-state p-AKT levels. Further, embelin, a small-molecule inhibitor that abrogates binding of XIAP to procaspase-9, caused significant decrease in SUM190PT viability. However, embelin in combination with trastuzumab failed to affect SUM190PT viability because it has no direct effect on XIAP, which is induced by trastuzumab treatment. These data have identified a novel functional link between ErbB2 signaling and antiapoptotic pathway mediated by XIAP. Blockade of the IAP antiapoptotic pathway alone or in combination would be an attractive strategy in IBC therapy.

Authors
Aird, KM; Ding, X; Baras, A; Wei, J; Morse, MA; Clay, T; Lyerly, HK; Devi, GR
MLA Citation
Aird, KM, Ding, X, Baras, A, Wei, J, Morse, MA, Clay, T, Lyerly, HK, and Devi, GR. "Trastuzumab signaling in ErbB2-overexpressing inflammatory breast cancer correlates with X-linked inhibitor of apoptosis protein expression." Mol Cancer Ther 7.1 (January 2008): 38-47.
PMID
18202008
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
7
Issue
1
Publish Date
2008
Start Page
38
End Page
47
DOI
10.1158/1535-7163.MCT-07-0370

Long term disease-free survival and T cell and antibody responses in women with high-risk Her2+ breast cancer following vaccination against Her2.

BACKGROUND: The HER2-inhibiting antibody trastuzumab, in combination with chemotherapy, significantly improves survival of women with resected, HER2-overexpressing breast cancers, but is associated with toxicities including a risk of cardiomyopathy. Additionally, the beneficial effect of trastuzumab is expected to decrease once the drug is discontinued. We proposed to address these concerns by using cancer vaccines to stimulate HER2 intracellular domain (ICD)-specific T cell and antibody responses. METHODS: Subjects with stage II (> or = 6 +LN), III, or stage IV breast cancer with > 50% HER2 overexpressing tumor cells who were disease-free after surgery and adjuvant therapy were eligible. Vaccines consisted of immature, cultured DC (n = 3), mature cultured DC (n = 3), or mature Flt3-ligand mobilized peripheral blood DC (n = 1) loaded with ICD, or tetanus toxoid, keyhole limpet hemocyanin or CMV peptide as controls, and were administered intradermally/subcutaneously four times at 3 week intervals. ICD-specific T cell and antibody responses were measured. Cardiac function was determined by MUGA or ECHO; long term disease status was obtained from patient contact. RESULTS: All seven patients successfully underwent DC generation and five received all 4 immunizations. There were no toxicities greater than grade 1 or ejection fraction decrements below normal. Delayed-type hypersensitivity (DTH) reactions at the injection site occurred in 6/7 patients and HER2 specificity was detected by cytokine flow cytometry or ELISPOT in 5 patients. At more than 5 years of follow-up, 6/7 had detectable anti-ICD antibodies. One patient experienced a pulmonary recurrence at 4 years from their study immunizations. This recurrence was resected and they are without evidence of disease. All patients are alive and disease-free at 4.6-6.7 years of follow-up. CONCLUSION: Although this was a small pilot study, the well-tolerated nature of the vaccines, the lack of cardiac toxicity, significant immunogenicity, and a 100% 4.5-year survival rate suggest that vaccination with HER2 ICD protein-containing DC is appropriate for further study in this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT00005956.

Authors
Morse, MA; Hobeika, A; Osada, T; Niedzwiecki, D; Marcom, PK; Blackwell, KL; Anders, C; Devi, GR; Lyerly, HK; Clay, TM
MLA Citation
Morse, MA, Hobeika, A, Osada, T, Niedzwiecki, D, Marcom, PK, Blackwell, KL, Anders, C, Devi, GR, Lyerly, HK, and Clay, TM. "Long term disease-free survival and T cell and antibody responses in women with high-risk Her2+ breast cancer following vaccination against Her2. (Published online)" J Transl Med 5 (September 6, 2007): 42-.
PMID
17822557
Source
pubmed
Published In
Journal of Translational Medicine
Volume
5
Publish Date
2007
Start Page
42
DOI
10.1186/1479-5876-5-42

siRNA-based approaches in cancer therapy.

The availability of the human genome sequence has revolutionized the strategy of employing nucleic acids with sequences complementary to specific target genes to improve drug discovery and target validation. Development of sequence-specific DNA or RNA analogs that can block the activity of selected single-stranded genetic sequences offers the possibility of rational design with high specificity, lacking in many current drug treatments for various diseases including cancer, at relatively inexpensive costs. Antisense technology is one such example that has shown promising results and boasts of yielding the only approved drug to date in the genomics field. However, in vivo delivery issues have yet to be completely overcome for widespread clinical applications. In contrast to antisense oligonucleotides, the mechanism of silencing an endogenous gene by the introduction of a homologous double-stranded RNA (dsRNA), transgene or virus is called post-transcriptional gene silencing (PTGS) or RNA interference. PTGS is a natural mechanism whereby metazoan cells suppress expansion of genes when they come across dsRNA molecules with the same sequence. Short interfering RNA is currently the fastest growing sector of this antigene field for target validation and therapeutic applications. Although, in theory, the development of genomics-based agents to inhibit gene expression is simple and straightforward, the fundamental concern relies upon the capacity of the oligonucleotide to gain access to the target RNA. This paper summarizes the advances in the last decade in the field of PTGS using RNA interference approaches and provides relevant comparisons with other oligonucleotide-based approaches with a specific focus on oncology applications.

Authors
Devi, GR
MLA Citation
Devi, GR. "siRNA-based approaches in cancer therapy." Cancer Gene Ther 13.9 (September 2006): 819-829. (Review)
PMID
16424918
Source
pubmed
Published In
Cancer Gene Therapy
Volume
13
Issue
9
Publish Date
2006
Start Page
819
End Page
829
DOI
10.1038/sj.cgt.7700931

In vivo bioavailability and pharmacokinetics of a c-MYC antisense phosphorodiamidate morpholino oligomer, AVI-4126, in solid tumors.

Phosphorodiamidate morpholino oligomers (PMO) inhibit targeted gene expression by preventing ribosomal assembly, thereby preventing mRNA translation. AVI-4126, a PMO targeted against c-MYC, has been extensively characterized in multiple cancer and other disease models and is currently in human clinical trials. A phase I clinical study was conducted to address the issue of PMO bioavailability in malignant tumors surgically excised from patients with adenocarcinoma of prostate and breast 1 day after i.v. administration of a single dose of 90 mg AVI-4126 PMO. The study objectives were to evaluate safety, to determine AVI-4126 concentration in tissue samples of the tumors, and to examine the distribution of AVI-4126 (margin versus tumor core). Significant concentrations of intact PMO similar to the animal models were detected in both human prostate and breast tumor tissues with increased distribution in the tumor core for the vascular breast tumors. No serious adverse events (graded according to National Cancer Institute Common Toxicity Criteria) were reported. Another phase I study was conducted in normal human volunteers to assess AVI-4126 plasma pharmacokinetics following single i.v. administration of 90 mg AVI-4126. Data from both human studies indicated similar plasma concentration-time profile. These studies show PMO bioavailability in tumor tissue and establish the feasibility of using PMO targeting specific genes in human cancer clinical trials.

Authors
Devi, GR; Beer, TM; Corless, CL; Arora, V; Weller, DL; Iversen, PL
MLA Citation
Devi, GR, Beer, TM, Corless, CL, Arora, V, Weller, DL, and Iversen, PL. "In vivo bioavailability and pharmacokinetics of a c-MYC antisense phosphorodiamidate morpholino oligomer, AVI-4126, in solid tumors." Clin Cancer Res 11.10 (May 15, 2005): 3930-3938.
PMID
15897595
Source
pubmed
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
11
Issue
10
Publish Date
2005
Start Page
3930
End Page
3938
DOI
10.1158/1078-0432.CCR-04-2091

Neutrally charged phosphorodiamidate morpholino antisense oligomers: uptake, efficacy and pharmacokinetics.

Antisense technology constitutes development of sequence-specific DNA or RNA analogs that can block the activity of selected single-stranded genetic sequences and offer the potential of high specificity lacking in many current drug treatments. The sequencing of the human genome has greatly increased the potential of this approach. Antisense oligonucleotides, the most commonly used antisense approach, are unmodified or chemically modified single stranded RNA or DNA molecules specifically designed to hybridize to corresponding RNA by Watson-Crick binding. Phosphorodiamidate Morpholino oligomers (PMO) are a novel class of non-ionic antisense agents that inhibit gene expression by binding to RNA and sterically blocking processing or translation. PMOs have shown excellent efficiency and safety profile via various routes of administration in multiple animal and human studies. This review will summarize the preclinical studies with PMOs on the road to their development as therapeutic agents with particular emphasis on in vivo biodistribution and pharmacokinetics.

Authors
Arora, V; Devi, GR; Iversen, PL
MLA Citation
Arora, V, Devi, GR, and Iversen, PL. "Neutrally charged phosphorodiamidate morpholino antisense oligomers: uptake, efficacy and pharmacokinetics." Curr Pharm Biotechnol 5.5 (October 2004): 431-439.
PMID
15544491
Source
pubmed
Published In
Current Pharmaceutical Biotechnology
Volume
5
Issue
5
Publish Date
2004
Start Page
431
End Page
439

Genomics-based anti-cancer drug discovery - Preface

Authors
Devi, GR
MLA Citation
Devi, GR. "Genomics-based anti-cancer drug discovery - Preface." CURRENT PHARMACEUTICAL BIOTECHNOLOGY 5.5 (October 2004).
Source
wos-lite
Published In
Current Pharmaceutical Biotechnology
Volume
5
Issue
5
Publish Date
2004

Androgen receptor down-regulation in prostate cancer with phosphorodiamidate morpholino antisense oligomers.

PURPOSE: Androgen receptor (AR) has a pivotal role in the growth and proliferation of prostate cancer (PCa). Even in advanced stages of PCa AR continues to be expressed and appears to be functional. Since the mechanisms of AR activation in androgen independent PCa have yet to be clearly defined, the decrease in AR protein by antisense compounds is an attractive therapeutic option. In this study we evaluated a novel antisense phosphorodiamidate morpholino oligomer (PMO) targeting the translational start site of AR mRNA in vitro and in vivo in a PCa xenograft and murine prostate. MATERIALS AND METHODS: AR antisense PMOs targeting the AR initiation AUG were tested in vitro and in LNCaP cells, and in vivo in LAPC-4 xenografts and normal mouse prostate. Effects on AR protein and PSA expression were assessed. RESULTS: AR antisense PMOs specifically down-regulated AR protein levels in a plasmid based screening system and also decreased endogenous AR levels in androgen responsive LNCaP cells in culture compared to control nonspecific PMOs. Pretreatment and posttreatment biopsies in the LAPC-4 xenograft model demonstrated that the antisense AR PMO administered intraperitoneally specifically decreased AR protein levels and serum PSA. Analysis of tissue distribution of the AR PMO by high performance liquid chromatography based methodology showed significant PMO levels in tumor tissue and mouse prostate, and there was a dose dependent decrease in AR protein levels in murine AR antisense PMO treated mouse prostates. CONCLUSIONS: An AR antisense PMO with unique chemical properties administered once daily can decrease AR protein levels and PSA in vivo. The reduction of AR protein with an antisense PMO may be an effective method of interfering with AR mediated growth in advanced human PCa.

Authors
Ko, Y-J; Devi, GR; London, CA; Kayas, A; Reddy, MT; Iversen, PL; Bubley, GJ; Balk, SP
MLA Citation
Ko, Y-J, Devi, GR, London, CA, Kayas, A, Reddy, MT, Iversen, PL, Bubley, GJ, and Balk, SP. "Androgen receptor down-regulation in prostate cancer with phosphorodiamidate morpholino antisense oligomers." J Urol 172.3 (September 2004): 1140-1144.
PMID
15311058
Source
pubmed
Published In
The Journal of Urology
Volume
172
Issue
3
Publish Date
2004
Start Page
1140
End Page
1144
DOI
10.1097/01.ju.0000134698.87862.e6

X-linked inhibitor of apoptosis protein inhibition induces apoptosis and enhances chemotherapy sensitivity in human prostate cancer cells.

Androgen-insensitive prostate cancer cells are highly resistant to several chemotherapeutic drugs and are characterized by the appearance of apoptosis-resistant cells. In this study, we identified the critical role of X-linked inhibitor of apoptosis protein (XIAP), a potent antiapoptotic factor, in conferring chemotherapy resistance in an androgen-insensitive DU145 human prostate cancer cell line. Results reveal that DU145 cells were highly resistant to cisplatin, but this resistance was overridden when the cells were treated for a prolonged time (>96 hours) with cisplatin (IC(50) = 27.5 to 35.5 micromol/L). A decrease in levels of XIAP and Akt/phospho-Akt and an increase in caspase-3 activity were identified to be key factors in cisplatin sensitivity (40% to 55% decrease in cell viability) at later time points. In contrast, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) treatment caused a 40% to 50% decrease in cell viability within 6 hours (IC(50) = 135 to 145 ng/mL). However, increasing concentrations or prolonged treatment with TRAIL did not change drug potency. A significant increase in caspase-3 activity was observed with TRAIL treatment with no apparent change in XIAP levels. Specific inhibition of XIAP expression using an antisense XIAP phosphorodiamidate morpholino oligomer induced apoptosis and increased caspase-3 activity. Combination of cisplatin with XIAP antisense potentiated cisplatin sensitivity by decreasing the IC(50) from >200 micromol/L with cisplatin alone to 9 to 20 micromol/L and decreasing incubation time required for activity from 96 to 24 hours. Similarly, TRAIL in combination with XIAP antisense phosphorodiamidate morpholino oligomer enhanced TRAIL potency by 12- to 13-fold. In conclusion, abrogation of XIAP expression is essential for therapeutic apoptosis and enhanced chemotherapy sensitization in androgen-refractory prostate cancer cells.

Authors
Amantana, A; London, CA; Iversen, PL; Devi, GR
MLA Citation
Amantana, A, London, CA, Iversen, PL, and Devi, GR. "X-linked inhibitor of apoptosis protein inhibition induces apoptosis and enhances chemotherapy sensitivity in human prostate cancer cells." Mol Cancer Ther 3.6 (June 2004): 699-707.
PMID
15210856
Source
pubmed
Published In
Molecular cancer therapeutics
Volume
3
Issue
6
Publish Date
2004
Start Page
699
End Page
707

XIAP as target for therapeutic apoptosis in prostate cancer.

Progression to androgen independence combined with chemotherapy resistance remains one of the primary obstacles to the improvement of quality of life and survival for patients with advanced prostate cancer. One unique feature of the androgen-independent cell population is that they still retain the appropriate machinery for apoptosis. Therefore, identifying a cure for prostate cancer requires identification and reversal of the antiapoptotic mechanisms responsible for drug resistance and/or newer therapies that bypass the apoptosis-resistance pathways. The key element in the apoptotic pathway is the processing and activation of caspases by either a mitochondrial-dependent or -independent cascade of events. XIAP, a member of the inhibitor of apoptosis family of proteins (IAP), has been identified as a potent caspase inhibitor. XIAP expression seems to be regulated by the presence of a rare sequence, internal ribosome entry sequence (IRES) in its 5' untranslated region (5' UTR) which facilitates its antiapoptotic function during any kind of induced-cellular stress like radiation and chemotherapy, making it an attractive therapeutic target. This review attempts to present an overview of the interaction between cell survival and death pathways, mechanism of XIAP action and recent studies supporting XIAP as an emerging therapeutic target.

Authors
Devi, GR
MLA Citation
Devi, GR. "XIAP as target for therapeutic apoptosis in prostate cancer." Drug News Perspect 17.2 (March 2004): 127-134. (Review)
PMID
15098067
Source
pubmed
Published In
Drug news & perspectives
Volume
17
Issue
2
Publish Date
2004
Start Page
127
End Page
134

Preface

Authors
Devi, GR
MLA Citation
Devi, GR. "Preface." Current Pharmaceutical Biotechnology 5.5 (2004): xxx-.
Source
scival
Published In
Current Pharmaceutical Biotechnology
Volume
5
Issue
5
Publish Date
2004
Start Page
xxx

Androgen receptor downregulation in prostate cancer with phosphorodiamidate morpholino antisense oligomers.

Authors
Ko, YJ; Devi, GR; London, CA; Kayas, A; Reddy, MT; Iverson, PL; Bubley, GJ; Balk, SP
MLA Citation
Ko, YJ, Devi, GR, London, CA, Kayas, A, Reddy, MT, Iverson, PL, Bubley, GJ, and Balk, SP. "Androgen receptor downregulation in prostate cancer with phosphorodiamidate morpholino antisense oligomers." December 1, 2003.
Source
wos-lite
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
9
Issue
16
Publish Date
2003
Start Page
6084S
End Page
6084S

A novel antisense inhibitor of MMP-9 attenuates angiogenesis, human prostate cancer cell invasion and tumorigenicity.

Androgen deprivation therapy causes a paradoxical elevation of matrix metalloproteinases (MMPs) including MMP-9 resulting in aggressive tumor phenotype in many patients with prostate cancer. In this study, we have evaluated a novel antisense phosphorodiamidate Morpholino oligomer (PMO) targeted against MMP-9 in models of angiogenesis and in human prostate xenograft in athymic mice. The treatment of androgen-independent DU145 human prostate cells with a 21-mer MMP-9 antisense PMO caused a dose-dependent inhibition of cell proliferation compared to scrambled or MMP-2 antisense PMO at similar concentrations. This was associated with decreases in MMP-9 expression, gelatinolytic activity and increased stability of the insulin-like growth factor-binding protein (IGFBP-3), a proapoptotic factor and MMP-9 substrate. In vitro invasion assays revealed a 40-60% inhibition of DU145 cell invasion in the presence of 25 microM MMP-9 antisense PMO. A significant decrease in endothelial cell migration and vascularization was observed in the Matrigel plug assay in mice when treated intraperitoneally with 300 microg/day MMP-9 antisense for 21 days. In the highly vascular DU145 tumor xenografts, MMP-9 inhibition caused decreased tumor growth with regression in 50% of the animals. Histological analysis revealed increased apoptosis and fibrous tissue deposits in the MMP-9 antisense-treated tumors compared to the scrambled and saline controls. No apparent toxicity or mortality was associated with the MMP-9 PMO treatment. In summary, the MMP-9 antisense PMO inhibited in vitro prostate cancer cell proliferation, invasion and in vivo angiogenesis. These data establish the feasibility of developing a site-directed, nontoxic antisense therapeutic agent for inhibiting local invasion and metastasis.

Authors
London, CA; Sekhon, HS; Arora, V; Stein, DA; Iversen, PL; Devi, GR
MLA Citation
London, CA, Sekhon, HS, Arora, V, Stein, DA, Iversen, PL, and Devi, GR. "A novel antisense inhibitor of MMP-9 attenuates angiogenesis, human prostate cancer cell invasion and tumorigenicity." Cancer Gene Ther 10.11 (November 2003): 823-832.
PMID
14605668
Source
pubmed
Published In
Cancer Gene Therapy
Volume
10
Issue
11
Publish Date
2003
Start Page
823
End Page
832
DOI
10.1038/sj.cgt.7700642

Efficacy of antisense morpholino oligomer targeted to c-myc in prostate cancer xenograft murine model and a Phase I safety study in humans.

PURPOSE: The overexpression of c-myc associated with uncontrolled cell proliferation is a frequent genetic event in androgen-refractory prostatic neoplasia. The purpose of this study was to evaluate the bioavailability and efficacy of a novel antisense phosphorodiamidate morpholino oligomer directed against c-myc, AVI-4126, in PC-3 androgen-independent human prostate cancer xenograft murine model and its safety in a Phase I human clinical study. EXPERIMENTAL DESIGN: AVI-4126 administration in athymic mice bearing s.c. PC-3 xenografts was carried out to determine the bioavailability, tolerance, antitumor activity, and histological changes induced by targeted inhibition of c-Myc expression using a specific morpholine antisense oligomer. The Phase I safety study involved a single center, open label, dose-escalating design in healthy volunteers after i.v. administration of AVI-4126. RESULTS: The data reveal that AVI-4126 targets and inhibits c-myc translation in a sequence-specific manner and causes significant growth inhibition and apoptosis in prostate cancer cells and in s.c. tumor xenografts. A 75-80% reduction in tumor burden was observed in AVI-4126-treated animals compared with the scrambled oligomer and saline control groups. Histologically, tumors grown in the athymic mice treated with AVI-4126 were less cellular and vascular than those in control mice and showed an increased level of cellular degeneration, cytoplasmic vacuoles, and hyperchromatic nuclei. Phase I safety trials in humans via i.v. route of administration showed no toxicity or serious adverse events. CONCLUSIONS: The present study demonstrates that inhibition of c-Myc expression by antisense phosphorodiamidate morpholino oligomer is a promising new and safe therapeutic strategy for prostate cancer.

Authors
Iversen, PL; Arora, V; Acker, AJ; Mason, DH; Devi, GR
MLA Citation
Iversen, PL, Arora, V, Acker, AJ, Mason, DH, and Devi, GR. "Efficacy of antisense morpholino oligomer targeted to c-myc in prostate cancer xenograft murine model and a Phase I safety study in humans." Clin Cancer Res 9.7 (July 2003): 2510-2519.
PMID
12855625
Source
pubmed
Published In
Clinical cancer research : an official journal of the American Association for Cancer Research
Volume
9
Issue
7
Publish Date
2003
Start Page
2510
End Page
2519

Resistance to chemotherapeutic drugs overcome by c-Myc inhibition in a Lewis lung carcinoma murine model.

Chemotherapy resistance is a significant obstacle in lung cancer therapy, and has been found to frequently correlate with amplification and overexpression of the c-myc oncogene. Earlier studies have shown that c-Myc inhibition alone is not always effective in cancer models. The purpose of this study was to test different dosing regimen, which included commonly used chemotherapeutic drugs in combination with c-Myc inhibition in a Lewis lung syngeneic drug-resistant murine tumor model. Inhibition of c-myc was specifically achieved by using phosphorodiamidate Morpholino oligomer (PMOs), a novel, non-toxic antisense DNA chemistry for inhibition of gene expression by an RNase H-independent mechanism. When administration of cisplatin overlapped with c-myc PMO (AVI-4126) treatment there was no additional effect on tumor growth inhibition compared to cisplatin alone. In contrast, using a dosing regimen in which cisplatin or taxol treatment preceded AVI-4126, a dramatic decrease in tumor growth rate was observed with tumor areas less then 0.5 cm2 in 60% of the animals at the end of the study. This effect was specific to c-Myc inhibition as other antisense PMOs against p21 or Rad51 showed no such effect in combination with chemotherapy. Immunoblot and HPLC-based analysis of tumor lysates at the end of the study confirmed c-Myc inhibition and detection of intact AVI-4126, respectively. In conclusion, AVI-4126 potentiates the efficacy of chemotherapeutic drugs in a manner that is schedule dependent.

Authors
Knapp, DC; Mata, JE; Reddy, MT; Devi, GR; Iversen, PL
MLA Citation
Knapp, DC, Mata, JE, Reddy, MT, Devi, GR, and Iversen, PL. "Resistance to chemotherapeutic drugs overcome by c-Myc inhibition in a Lewis lung carcinoma murine model." Anticancer Drugs 14.1 (January 2003): 39-47.
PMID
12544257
Source
pubmed
Published In
Anti-Cancer Drugs
Volume
14
Issue
1
Publish Date
2003
Start Page
39
End Page
47

In vivo efficacy of phosphorodiamidate morpholino-based antisense oligomers in tumor and angiogenesis models

Authors
London, CA; Knapp, DC; Ko, YJ; Balk, S; DeSouza, M; Farrell, DH; Iversen, PL; Devi, GR
MLA Citation
London, CA, Knapp, DC, Ko, YJ, Balk, S, DeSouza, M, Farrell, DH, Iversen, PL, and Devi, GR. "In vivo efficacy of phosphorodiamidate morpholino-based antisense oligomers in tumor and angiogenesis models." January 2003.
Source
wos-lite
Published In
Cancer Gene Therapy
Volume
10
Publish Date
2003
Start Page
S3
End Page
S4

Gene Therapy of Cancer - 11th International Conference: 12-14 December 2002, San Diego, USA

At this excellent meeting, preclinical, phase I and some phase II data were presented concerning significant advances with various viral and non-viral-based vectors. In addition, a few talks discussed genomic-based therapies such as those involving antisense oligomers with novel chemistries and backbone modifications. The presentations covered some of the common issues concerning gene therapy, which include bioavailability, delivery strategies, toxicity and dosing schedules.

Authors
Devi, G
MLA Citation
Devi, G. "Gene Therapy of Cancer - 11th International Conference: 12-14 December 2002, San Diego, USA." 2003.
Source
scival
Published In
IDrugs
Volume
6
Issue
2
Publish Date
2003
Start Page
104
End Page
106

Morpholino antisense oligomer to integrin alpha, inhibits angiogenesis in a mouse model of retinopathy of prematurity.

Authors
De Sousa, MA; Davies, MH; London, CA; Powers, MR; Devi, GR; Farrell, DH
MLA Citation
De Sousa, MA, Davies, MH, London, CA, Powers, MR, Devi, GR, and Farrell, DH. "Morpholino antisense oligomer to integrin alpha, inhibits angiogenesis in a mouse model of retinopathy of prematurity." November 16, 2002.
Source
wos-lite
Published In
Blood
Volume
100
Issue
11
Publish Date
2002
Start Page
680A
End Page
680A

Inhibition of human chorionic gonadotropin beta-subunit modulates the mitogenic effect of c-myc in human prostate cancer cells.

BACKGROUND: Amplification of the proto-oncogene c-myc has been identified as one of the most common genetic alterations in prostate cancer, thus making it an attractive therapeutic target. However, certain prostate cancer cells are unresponsive to c-Myc inhibition. The purpose of this study was to test the hypothesis that effective growth inhibition in the refractory cancer cells can be achieved by blocking c-myc along with a growth factor using a novel phosphorodiamidate morpholino antisense oligomer-based approach. Human chorionic gonadotropin, a growth factor implicated in neoplasm, causes activation of c-myc through a G-protein-coupled pathway of signal transduction. METHODS: In this study, the effect of inhibition of beta-hCG and c-myc singly or in combination was evaluated in DU145 (RB -/-, p53-/-, androgen-independent) and LNCaP (Rb+/+, p53 +/+, androgen-sensitive) human prostate cancer cell lines and in a DU145 subcutaneous xenograft murine model. RESULTS: Antisense phosphorodiamidate morpholino oligomers directed against beta-hCG and c-myc caused a specific decrease of the target protein levels. Unlike LNCaP cells, DU145 cell growth was refractory to c-Myc inhibition. Unresponsiveness to c-myc inhibition in DU145 cells was overcome by targeting both beta-hCG and c-myc genes, resulting in potentiation of the antiproliferative effect seen with inhibition of beta-hCG alone. CONCLUSIONS: The inhibition of beta-hCG sensitizes prostate cancer cells to the antiproliferative effects of c-Myc inhibition, including tumors that are refractory to c-Myc decrease alone.

Authors
Devi, GR; Oldenkamp, JR; London, CA; Iversen, PL
MLA Citation
Devi, GR, Oldenkamp, JR, London, CA, and Iversen, PL. "Inhibition of human chorionic gonadotropin beta-subunit modulates the mitogenic effect of c-myc in human prostate cancer cells." Prostate 53.3 (November 1, 2002): 200-210.
PMID
12386920
Source
pubmed
Published In
The Prostate
Volume
53
Issue
3
Publish Date
2002
Start Page
200
End Page
210
DOI
10.1002/pros.10151

Insulin-like growth factor binding protein-3 induces early apoptosis in malignant prostate cancer cells and inhibits tumor formation in vivo.

BACKGROUND: Insulin-like growth factor binding protein (IGFBP-3) levels are significantly reduced in malignant prostate epithelial cells. In this study, we evaluated the role of endogenous IGFBP-3 on prostate cancer cell growth and tumorigenesis. METHODS: IGFBP-3 was re-expressed by stable transfection of human IGFBP-3 cDNA in a model of human prostate cancer, M12, a malignant subline in which IGFBP-3 levels are undetectable in comparison to the parent epithelial cell, P69. Effect of IGFBP-3 re-expression (M12-BP-3) on growth kinetics, morphology, propensity to apoptosis, and in vivo tumor formation were studied. RESULTS: M12-BP-3 cells secreted IGFBP-3 and growth arrested at a cell density that was threefold lower than control cells and this was associated with marked alteration in cell morphology. Control cells when grown in conditioned media secreted by M12-BP-3 also showed altered morphology compared to when cultured in IGFBP-3-immunodepleted conditioned media. The M12-BP-3 clones showed altered mitochondrial membrane potential, increased PARP cleavage, increase in sub-G1 peak, decreased levels of neuron specific enolase, and decreased tumor formation in athymic, nude mice. CONCLUSIONS: These data suggest that IGFBP-3 induces early apoptosis and has potential tumor suppressive effect in prostate cancer. Prostate 51: 141-152, 2002.

Authors
Devi, GR; Sprenger, CC; Plymate, SR; Rosenfeld, RG
MLA Citation
Devi, GR, Sprenger, CC, Plymate, SR, and Rosenfeld, RG. "Insulin-like growth factor binding protein-3 induces early apoptosis in malignant prostate cancer cells and inhibits tumor formation in vivo." Prostate 51.2 (May 1, 2002): 141-152.
PMID
11948969
Source
pubmed
Published In
The Prostate
Volume
51
Issue
2
Publish Date
2002
Start Page
141
End Page
152
DOI
10.1002/pros.10068

Inhibition of tumor growth using an antisense morpholino oligomer to integrin alpha(v) subunit

Authors
De Sousa, MA; Bird, JD; London, CA; Iversen, PL; Devi, GR; Farrell, DH
MLA Citation
De Sousa, MA, Bird, JD, London, CA, Iversen, PL, Devi, GR, and Farrell, DH. "Inhibition of tumor growth using an antisense morpholino oligomer to integrin alpha(v) subunit." May 2002.
Source
wos-lite
Published In
Arteriosclerosis, Thrombosis, and Vascular Biology
Volume
22
Issue
5
Publish Date
2002
Start Page
A15
End Page
A15

Prostate cancer: status of current treatments and emerging antisense-based therapies.

Prostate cancer, like most other solid tumors, represents a heterogeneous entity consisting of a mixture of androgen-dependent and androgen-independent cells. Although proliferation of prostate tumor cells is often initially androgen-dependent, the inevitable development of androgen-insensitivity in late-stage prostate cancer renders androgen-suppressing treatments ultimately ineffective. Non-hormonal chemotherapy induces apoptosis in actively proliferating cells and is typically of little value, since prostate cancer demonstrates very slow growth kinetics. Objective response rates of < 10% and no improved survival rates have been observed in several hundred clinical studies using both experimental and approved chemotherapeutic agents. An improved understanding of the molecular mechanisms responsible for the onset of the disease, as well as the factors that control the proliferation of prostate cancer cells, have identified key changes in gene expression during cancer progression, especially from androgen-dependent to androgen-independent status. Manipulation of the genes implicated in disease progression represent an important approach for therapeutic intervention. This review summarizes recent progress that has been made with the use of antisense technology with various chemistries to modify gene expression, a strategy that seems to hold great promise for prostate cancer therapy.

Authors
Devi, GR
MLA Citation
Devi, GR. "Prostate cancer: status of current treatments and emerging antisense-based therapies." Curr Opin Mol Ther 4.2 (April 2002): 138-148. (Review)
PMID
12044035
Source
pubmed
Published In
Current Opinion in Molecular Therapeutics
Volume
4
Issue
2
Publish Date
2002
Start Page
138
End Page
148

Inhibition of human chorionic gonadotropin beta-subunit modulates the mitogenic effect of c-myc in human prostate cancer cells

Authors
Devi, GR; Oldenkamp, JR; Iversen, PL
MLA Citation
Devi, GR, Oldenkamp, JR, and Iversen, PL. "Inhibition of human chorionic gonadotropin beta-subunit modulates the mitogenic effect of c-myc in human prostate cancer cells." December 2001.
Source
wos-lite
Published In
Cancer Gene Therapy
Volume
8
Publish Date
2001
Start Page
S6
End Page
S6

Effect of IGFBP-3 on IGF- and IGF-analogue-induced insulin-like growth factor-I receptor (IGFIR) signalling.

Insulin-like growth factor binding protein-3 (IGFBP-3) binds IGF-I and IGF-II with high affinity, at least an order of magnitude higher than the affiniy of the IGFs for the IGFIR. It has been hypothesized that IGFBP-3 inhibits IGF binding to the IGFIR via a mechanism independent of its ability to sequester IGFs. In the present study, we examined the effects of IGFBP-3 and its proteolytic fragments on the initial events of the IGFIR signalling pathway. IGFBP-3 inhibited IGF-I-, IGF-II-, Des(1-3)IGF-I- and Long(R3)IGF-I-induced IGFIR phosphorylation in a dose-dependent manner at similar concentration range but not QAYL-induced IGFIR-P. The((1-97))IGFBP-3 fragment was able to inhibit only IGF-I-induced IGFIR-P. The((1-97))IGFBP-3 fragment but not intact IGFBP-3 inhibited insulin-induced IGFIR-P. Monolayer cross-linking with [(125)I]IGFBP-3 indicated that there is no direct interaction of IGFBP-3 with the IGFIR. This study demonstrates that the effect on the initial step of IGFIR signalling by IGFBP-3 is largely due to its ability to sequester IGF and the IGF analogues in the extracellular milieu and not the result of any interaction of IGFBP-3 with the IGFIR or a mechanism independent of its ability to bind IGFs.

Authors
Devi, GR; Graham, DL; Oh, Y; Rosenfeld, RG
MLA Citation
Devi, GR, Graham, DL, Oh, Y, and Rosenfeld, RG. "Effect of IGFBP-3 on IGF- and IGF-analogue-induced insulin-like growth factor-I receptor (IGFIR) signalling." Growth Horm IGF Res 11.4 (August 2001): 231-239.
PMID
11735239
Source
pubmed
Published In
Growth Hormone & IGF Research
Volume
11
Issue
4
Publish Date
2001
Start Page
231
End Page
239
DOI
10.1054/ghir.2001.0231

Characterization of Insulin-Like Growth Factor-Binding Protein-Related Proteins (IGFBP-rPs) 1, 2, and 3 in Human Prostate Epithelial Cells: Potential Roles for IGFBP-rP1 and 2 in Senescence of the Prostatic Epithelium.

Authors
Lo Pez-Bermejo, A; Buckway, CK; Devi, GR; Hwa, V; Plymate, SR; Oh, Y; Rosenfeld, RG
MLA Citation
Lo Pez-Bermejo, A, Buckway, CK, Devi, GR, Hwa, V, Plymate, SR, Oh, Y, and Rosenfeld, RG. "Characterization of Insulin-Like Growth Factor-Binding Protein-Related Proteins (IGFBP-rPs) 1, 2, and 3 in Human Prostate Epithelial Cells: Potential Roles for IGFBP-rP1 and 2 in Senescence of the Prostatic Epithelium." Endocrinology 141.11 (November 2000): 4072-4080.
PMID
28200881
Source
epmc
Published In
Endocrinology
Volume
141
Issue
11
Publish Date
2000
Start Page
4072
End Page
4080

Differential Effects of Insulin-Like Growth Factor (IGF)-Binding Protein-3 and Its Proteolytic Fragments on Ligand Binding, Cell Surface Association, and IGF-I Receptor Signaling* * This research was supported by US Army Grants DAMD17-991-9522 (to G.R.D.) and DAMD17-96-1-6204 and DAMD17-96-1-7204 (to Y.O.H.) and by NIH Grants R01-DK-51513 (to R.G.R.) and CA-58110 (to R.G.R.).

Authors
Devi, GR; Yang, D-H; Rosenfeld, RG; Oh, Y
MLA Citation
Devi, GR, Yang, D-H, Rosenfeld, RG, and Oh, Y. "Differential Effects of Insulin-Like Growth Factor (IGF)-Binding Protein-3 and Its Proteolytic Fragments on Ligand Binding, Cell Surface Association, and IGF-I Receptor Signaling* * This research was supported by US Army Grants DAMD17-991-9522 (to G.R.D.) and DAMD17-96-1-6204 and DAMD17-96-1-7204 (to Y.O.H.) and by NIH Grants R01-DK-51513 (to R.G.R.) and CA-58110 (to R.G.R.)." Endocrinology 141.11 (November 2000): 4171-4179.
PMID
28200747
Source
epmc
Published In
Endocrinology
Volume
141
Issue
11
Publish Date
2000
Start Page
4171
End Page
4179

Characterization of insulin-like growth factor-binding protein-related proteins (IGFBP-rPs) 1, 2, and 3 in human prostate epithelial cells: potential roles for IGFBP-rP1 and 2 in senescence of the prostatic epithelium.

Insulin-like growth factor (IGF)-binding protein (IGFBP)-related proteins (IGFBP-rPs) are newly described cysteine-rich proteins that share significant aminoterminal structural similarity with the conventional IGFBPs and are involved in a diversity of biological functions, including growth regulation. IGFBP-rP1 (MAC25/Angiomodulin/prostacyclin-stimulating factor) is a potential tumor-suppressor gene that is differentially expressed in meningiomas, mammary and prostatic cancers, compared with their malignant counterparts. We have previously shown that IGFBP-rP1 is preferentially produced by primary cultures of human prostate epithelial cells (HPECs) and by poorly tumorigenic P69SV40T cells, compared with the cancerous prostatic LNCaP, DU145, PC-3, and M12 cells. We now show that IGFBP-rP1 increases during senescence of HPEC. IGFBP-rP2 (also known as connective tissue growth factor), a downstream effector of transforming growth factor (TGF)-beta and modulator of growth for both fibroblasts and endothelial cells, was detected in most of the normal and malignant prostatic epithelial cells tested, with a marked up-regulation of IGFBP-rP2 during senescence of HPEC. Moreover, IGFBP-rP2 noticeably increased in response to TGF-beta1 and all-trans retinoic acid (atRA) in HPEC and PC-3 cells, and it decreased in response to IGF-I in HPEC. IGFBP-rP3 [nephroblastoma overexpressed (NOV)], the protein product of the NOV protooncogene, was not detected in HPEC but was expressed in the tumorigenic DU145 and PC-3 cells. It was also synthesized by the SV40-T antigen-transformed P69 and malignant M12 cells, where it was down-regulated by atRA. These observations suggest biological roles of IGFBP-rPs in the human prostate. IGFBP-rP1 and IGFBP-rP2 are likely to negatively regulate growth, because they seem to increase during senescence of the prostate epithelium and in response to growth inhibitors (TGF-beta1 and atRA). Although the data collected on IGFBP-rP3 in prostate are modest, its role as a growth stimulator and/or protooncogene is supported by its preferential expression in cancerous cells and its down-regulation by atRA.

Authors
López-Bermejo, A; Buckway, CK; Devi, GR; Hwa, V; Plymate, SR; Oh, Y; Rosenfeld, RG
MLA Citation
López-Bermejo, A, Buckway, CK, Devi, GR, Hwa, V, Plymate, SR, Oh, Y, and Rosenfeld, RG. "Characterization of insulin-like growth factor-binding protein-related proteins (IGFBP-rPs) 1, 2, and 3 in human prostate epithelial cells: potential roles for IGFBP-rP1 and 2 in senescence of the prostatic epithelium." Endocrinology 141.11 (November 2000): 4072-4080.
PMID
11089538
Source
pubmed
Published In
Endocrinology
Volume
141
Issue
11
Publish Date
2000
Start Page
4072
End Page
4080
DOI
10.1210/endo.141.11.7783

Differential effects of insulin-like growth factor (IGF)-binding protein-3 and its proteolytic fragments on ligand binding, cell surface association, and IGF-I receptor signaling.

Insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3), the predominant IGF carrier protein in circulation, is posttranslationally modified in vivo by IGFBP-3 protease(s) into a number of fragments. Based on the ascertained and predicted recognition sites for known IGFBP-3 proteases, FLAG-epitope tagged intact IGFBP-3, NH2-terminal (1-97), intermediate fragment (88-148), and COOH-terminal fragments (98-264) and (184-264) were generated in a baculovirus and/or Escherichia coli expression system and examined, by Western ligand blot and affinity cross-linking assays, for their ability to bind IGF and insulin. The NH2- and COOH-terminal fragments bound both IGF and insulin specifically (albeit with significantly reduced affinity) for IGF but higher affinity for insulin, when compared with intact IGFBP-3. The effect of IGFBP-3 and the fragments on IGF-I receptor (IGFIR) signaling pathways was studied by testing IGF-I-induced receptor autophosphorylation in IGFIR-overexpressing NIH-3T3 cells. IGFBP-3 showed a dose-dependent inhibition of autophosphorylation of the beta-subunit of IGFIR. The (1-97)NH2-terminal fragment inhibited IGFIR autophosphorylation at high concentrations, and this effect seems largely attributable to sequestration of IGF-I. In contrast, no inhibition of IGF-I-induced IGFIR autophosphorylation was detectable with the (98-264) and (184-264) COOH-terminal fragments, despite their ability to bind IGF. However, unlike the (1-97)NH2-terminal fragment, the COOH-terminal fragments of IGFBP-3 retained their ability to associate with the cell surface, and this binding was competed by heparin, similar to intact IGFBP-3.

Authors
Devi, GR; Yang, DH; Rosenfeld, RG; Oh, Y
MLA Citation
Devi, GR, Yang, DH, Rosenfeld, RG, and Oh, Y. "Differential effects of insulin-like growth factor (IGF)-binding protein-3 and its proteolytic fragments on ligand binding, cell surface association, and IGF-I receptor signaling." Endocrinology 141.11 (November 2000): 4171-4179.
PMID
11089550
Source
pubmed
Published In
Endocrinology
Volume
141
Issue
11
Publish Date
2000
Start Page
4171
End Page
4179
DOI
10.1210/endo.141.11.7781

The insulin-like growth factor binding protein superfamily: new perspectives.

The insulin-like growth factor (IGF) binding proteins (IGFBPs) were initially identified as carrier proteins for IGF-I and IGF-II in a variety of biologic fluids. Their presumed function was to protect IGF peptides from degradation and clearance, increase the half-life of the IGFs, and deliver them to appropriate tissue receptors. The concept of IGFBPs as simple carrier proteins has been complicated, however, by a number of observations: 1) the six IGFBPs vary in their tissue expression and their regulation by other hormones and growth factors; 2) the IGFBPs are subjected to proteolytic degradation, thereby altering their affinities for the IGFs; 3) IGFBP-3 and IGFBP-5, in addition to binding IGFs, also can associate with an acid-labile subunit, thereby increasing further the half-life of the IGFs; 4) in addition to modifying the access of IGF peptides to IGF and insulin receptors, several of the IGFBPs may be capable of increasing IGF action; 5) some of the IGFBPs may be capable of IGF-independent regulation of cell growth; 6) some of the IGFBPs are associated with cell membranes or possibly with membrane receptors; and 7) some of the IGFBPs have nuclear recognition sites and may be found within the nucleus. Additionally, a number of cDNAs identified recently have been found to encode proteins that bind IGFs, but with substantially lower affinities than is the case with IGFBPs. The N-terminal regions of the predicted proteins are structurally homologous to the classic IGFBPs, with conservation of the cysteine-rich region. These observations suggest that these low-affinity binders are members of an IGFBP superfamily, capable of regulating cell growth by both IGF-dependent and IGF-independent mechanisms.insulin-like growth factor, insulin-like growth factor binding proteins.

Authors
Rosenfeld, RG; Hwa, V; Wilson, L; Lopez-Bermejo, A; Buckway, C; Burren, C; Choi, WK; Devi, G; Ingermann, A; Graham, D; Minniti, G; Spagnoli, A; Oh, Y
MLA Citation
Rosenfeld, RG, Hwa, V, Wilson, L, Lopez-Bermejo, A, Buckway, C, Burren, C, Choi, WK, Devi, G, Ingermann, A, Graham, D, Minniti, G, Spagnoli, A, and Oh, Y. "The insulin-like growth factor binding protein superfamily: new perspectives." Pediatrics 104.4 Pt 2 (October 1999): 1018-1021.
PMID
10506255
Source
pubmed
Published In
Pediatrics
Volume
104
Issue
4 Pt 2
Publish Date
1999
Start Page
1018
End Page
1021

Altered ligand binding by insulin-like growth factor II/mannose 6-phosphate receptors bearing missense mutations in human cancers.

The M6P/IGF2R gene, encoding the insulin-like growth factor II (IGF-II)/mannose 6-phosphate receptor (IGF2R), is frequently inactivated during carcinogenesis. M6P/IGF2R is postulated to be a tumor suppressor gene due to its ability to bind and degrade the mitogen IGF-II, promote activation of the growth inhibitor transforming growth factor beta, and regulate the targeting of lysosomal enzymes. In this study, we determined the effects of four M6P/IGF2R missense mutations associated with loss of heterozygosity in hepatocellular and breast cancers on the ligand binding properties of full-length membrane-bound receptors. Site-directed mutagenesis was used to prepare COOH-terminal, c-myc epitope-tagged human IGF2R cDNA expression constructs bearing point mutations that lead to the substitutions I1572T, G1464E, G1449V, and Q1445H, all of which are located in the receptor's extracytoplasmic domain. Ligand binding was measured in plasma membranes from 293T cells expressing full-length receptors. No binding of 125I-IGF-II to I1572T mutant receptors was observed. Binding to G1449V mutant receptors was decreased by 50% relative to wild-type (WT). However, IGF-II binding to the G1464E and Q1445H mutant receptors was equivalent to WT when plasma membranes were assayed immediately after preparation. The phosphomannosylated pseudoglycoprotein pentamannose 6-phosphate-BSA (PMP-BSA) was synthesized as a ligand for the M6P binding site. Binding of 125I-PMP-BSA was equivalent to WT for the I1572T, G1464E, and Q1445H mutations, but there was a 60% reduction in PMP-BSA binding to the G1449V mutant receptor. Thus, several missense mutations in M6P/IGF2R disrupt the ligand binding functions of the intact IGF2R, lending further support to the hypothesis that the M6P/IGF2R is a tumor suppressor gene.

Authors
Devi, GR; De Souza, AT; Byrd, JC; Jirtle, RL; MacDonald, RG
MLA Citation
Devi, GR, De Souza, AT, Byrd, JC, Jirtle, RL, and MacDonald, RG. "Altered ligand binding by insulin-like growth factor II/mannose 6-phosphate receptors bearing missense mutations in human cancers." Cancer Res 59.17 (September 1, 1999): 4314-4319.
PMID
10485478
Source
pubmed
Published In
Cancer Research
Volume
59
Issue
17
Publish Date
1999
Start Page
4314
End Page
4319

Disruption of ligand binding to the insulin-like growth factor II/mannose 6-phosphate receptor by cancer-associated missense mutations.

The insulin-like growth factor II/mannose 6-phosphate receptor (IGF2R) carries out multiple regulatory and transport functions, and disruption of IGF2R function has been implicated as a mechanism to increase cell proliferation. Several missense IGF2R mutations have been identified in human cancers, including the following amino acid substitutions occurring in the extracytoplasmic domain of the receptor: Cys-1262 --> Ser, Gln-1445 --> His, Gly-1449 --> Val, Gly-1464 --> Glu, and Ile-1572 --> Thr. To determine what effects these mutations have on IGF2R function, mutant and wild-type FLAG epitope-tagged IGF2R constructs lacking the transmembrane and cytoplasmic domains were characterized for binding of insulin-like growth factor (IGF)-II and a mannose 6-phosphate-bearing pseudoglycoprotein termed PMP-BSA (where PMP is pentamannose phosphate and BSA is bovine serum albumin). The Ile-1572 --> Thr mutation eliminated IGF-II binding while not affecting PMP-BSA binding. Gly-1449 --> Val and Cys-1262 --> Ser each showed 30-60% decreases in the number of sites available to bind both (125)I-IGF-II and (125)I-PMP-BSA. In addition, the Gln-1445 --> His mutant underwent a time-dependent loss of IGF-II binding, but not PMP-BSA binding, that was not observed for wild type. In all, four of the five cancer-associated mutants analyzed demonstrated altered ligand binding, providing further evidence that loss of IGF2R function is characteristic of certain cancers.

Authors
Byrd, JC; Devi, GR; de Souza, AT; Jirtle, RL; MacDonald, RG
MLA Citation
Byrd, JC, Devi, GR, de Souza, AT, Jirtle, RL, and MacDonald, RG. "Disruption of ligand binding to the insulin-like growth factor II/mannose 6-phosphate receptor by cancer-associated missense mutations." J Biol Chem 274.34 (August 20, 1999): 24408-24416.
PMID
10446221
Source
pubmed
Published In
The Journal of biological chemistry
Volume
274
Issue
34
Publish Date
1999
Start Page
24408
End Page
24416

An insulin-like growth factor II (IGF-II) affinity-enhancing domain localized within extracytoplasmic repeat 13 of the IGF-II/mannose 6-phosphate receptor.

Insulin-like growth factor II (IGF-II) and phosphomannosylated glycoproteins bind to distinct sites on the same receptor, the IGF-II/mannose 6-phosphate receptor (IGF2R). Analysis of truncated receptors (minireceptors) has been used to map the IGF-II binding site within the receptor's extracytoplasmic domain, which consists of 15 homologous repeats. A minireceptor consisting of repeat 11 contained the minimal elements for binding IGF-II, but with 5- to 10-fold lower relative binding affinity than the full-length receptor. We hypothesized that the complete, high-affinity IGF-II binding site is formed by interaction between the primary site in repeat 11 and a putative affinity-enhancing domain. To determine the minimum portion of the IGF2R's extracytoplasmic domain needed for expression of high-affinity IGF-II binding, a nested set of FLAG epitope-tagged minireceptors encompassing repeats 11 through 15 was prepared and transiently expressed in 293T cells. Minireceptors containing repeats 11-13 or 11-15 exhibited high affinity, comparable to the full-length receptor (IC50 = 1-2 nM), whereas constructs containing repeat 11 only or repeats 11-12 did not (IC50 = 10-20 nM). These data suggested that the affinity-enhancing domain is located within repeat 13, which contains a unique 43-residue insert that has approximately 50% sequence identity to the type II repeat of fibronectin. Although a repeat 13 minireceptor did not bind IGF-II on its own, an 11-13 minireceptor containing a deletion of the 43-residue insert exhibited low IGF-II binding affinity (IC50 = 10-20 nM). Expression of mutant receptors from a full-length IGF2R construct bearing a deletion of the 43-residue insert was very low relative to wild type. Depletion assays using IGF-II-Sepharose showed that the mutant receptor had lower affinity for IGF-II than the wild-type receptor. This study reveals that two independent receptor domains are involved in the formation of a high-affinity binding site for IGF-II, and that a complete repeat 13 is required for high-affinity IGF-II binding.

Authors
Devi, GR; Byrd, JC; Slentz, DH; MacDonald, RG
MLA Citation
Devi, GR, Byrd, JC, Slentz, DH, and MacDonald, RG. "An insulin-like growth factor II (IGF-II) affinity-enhancing domain localized within extracytoplasmic repeat 13 of the IGF-II/mannose 6-phosphate receptor." Mol Endocrinol 12.11 (November 1998): 1661-1672.
PMID
9817593
Source
pubmed
Published In
Molecular endocrinology (Baltimore, Md.)
Volume
12
Issue
11
Publish Date
1998
Start Page
1661
End Page
1672
DOI
10.1210/mend.12.11.0192

Truncated forms of the insulin-like growth factor II (IGF-II)/mannose 6-phosphate receptor encompassing the IGF-II binding site: characterization of a point mutation that abolishes IGF-II binding.

Complete understanding of the functional significance of insulin-like growth factor II (IGF-II) binding by the IGF-II/mannose-6-phosphate (Man-6-P) receptor requires mapping and ultimately mutational analysis of the receptor's IGF-II binding domain. Recent advances have localized the IGF-II binding site to extracytoplasmic repeats 10-11. To improve resolution of the binding site map, a nested set of epitope-tagged, truncated forms of the human IGF-II/Man-6-P receptor were transiently expressed in COS-7 cells. The IGF-II binding properties of truncated receptors immunoprecipitated from cell lysates and conditioned media were determined by affinity cross-linking. From the largest truncated receptor, encompassing extracytoplasmic repeats 8-11 (M(r) 68 K), through the smallest, comprised primarily of repeat 11 (M(r) 23 K), all were able to bind and cross-link to IGF-II. As a group, the truncated receptors had similar affinities for IGF-II, but with relative binding affinities 5-to 10-fold lower than those of full-length receptors. A point mutation substituting threonine for isoleucine at residue 1572, located in the NH2-terminal half of repeat 11, completely abolished IGF-II binding. We conclude that repeat 11 of the IGF-II/Man-6-P receptor's extracytoplasmic domain contains the minimal elements required for binding and cross-linking to IGF-II, and that lle1572 and other residues within the NH2-terminal half of repeat 11 are particularly important for IGF-II interaction.

Authors
Garmroudi, F; Devi, G; Slentz, DH; Schaffer, BS; MacDonald, RG
MLA Citation
Garmroudi, F, Devi, G, Slentz, DH, Schaffer, BS, and MacDonald, RG. "Truncated forms of the insulin-like growth factor II (IGF-II)/mannose 6-phosphate receptor encompassing the IGF-II binding site: characterization of a point mutation that abolishes IGF-II binding." Mol Endocrinol 10.6 (June 1996): 642-651.
PMID
8776724
Source
pubmed
Published In
Molecular endocrinology (Baltimore, Md.)
Volume
10
Issue
6
Publish Date
1996
Start Page
642
End Page
651
DOI
10.1210/mend.10.6.8776724
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