bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3613: Down regulation of LIM kinase1 enhances taxane sensitivity of cancer cells
Authors: Ottman Richard , Chakrabarti Ratna
Published: June 2012

Taxane compounds, such as docetaxel and paclitaxel, are microtubule-targeted tubulin-polymerizing agents and have proven to be the first line of treatment choice for castration-resistant prostate cancer and tamoxifen-resistant breast cancer cells. However resistance to taxane compounds develops commonly due to altered beta tubulin isotypes or development of multidrug resistance (MDR) through activation of p-glycoprotein drug efflux pump. In addition there are serious side effects and systemic toxicity encountered with docetaxel treatment. There is a need to enhance the efficacy of the taxane compounds by identifying novel targets, inhibition of which would induce mitotic arrest and apoptosis. LIM kinase1 (LIMK1) is a serine/threonine kinase, which coordinates microtubule stability and reorganization of actin cytoskleton through inactivating phosphorylation of cofilin, and is involved in regulation of the mitotic process. LIMK1 is overexpressed in breast and prostate tumors and in breast and prostate cancer cells in culture. Ectopic expression of LIMK1 promotes altered cell cycle progression and mitotic defects. Furthermore, LIMK1 expression prevents normal cellular response to paclitaxel in prostate epithelial cells, such as metaphase arrest and retarded cell growth. In this study, we show that ectopic expression of LIMK1 in BPH-1 cells decreased cytotoxic effects of paclitaxel through reduction of the number of apoptotic cells. Cell viability analysis using MTT assay showed that LIMK1 expressing cells maintained a higher viable cell density compared to control cells following paclitaxel treatment. LIMK1 expression in BPH-1 cells also increased BCL2 expression and decreased translocation of BAX to mitochondria compared to control cells. siRNA-induced down regulation of LIMK1 expression increased docetaxel sensitivity of breast and prostate cancer cells. Flow cytometric analysis of LIMK1 siRNA treated cells showed increased percentage of apoptotic cells compared to control RNA treated cells. Western blot analysis showed increased cleavage of apoptotic markers PARP, caspase 3 and caspase 9 in LIMK1 shRNA transfected prostate cancer cells upon docetaxel treatment compared to cells transfected with scrambled shRNA. Our study suggests that targeted inhibition of LIMK1 expression may potentiate the effects of taxane compounds on breast and prostate cancer cells. This study will have a broad impact on management of castration-resistant prostate and tamoxifen-resistant/ER-apha negative breast cancer cells with increased sensitivity of taxane compounds at a lower dose and hence less systemic toxicity, which could be applicable to other types of cancers as well.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3613. doi:10.1158/1538-7445.AM2011-3613
Abstract 3626: Targeting of essential gene products in breast cancer with cell penetrating neutralizing antibodies
Authors: Agnes Richard S. , Wang Jing , Basilion James P.
Published: June 2012

We present a novel nuclear, targeted therapeutic strategy that disrupts intracellular essential gene products selectively in tumors. Therapeutic antibodies against external cell surface receptors are effective. However, the limited permeability of antibodies through cellular and nuclear membranes restricts their use as therapeutics for targeting intracellular gene products of cancer cells. Many of the oldest and most efficacious cancer chemotherapeutic agents target cellular elements essential to the growth and proliferation of all cells (e.g. DNA with alkylating agents or dihydrofolate reductase with methotrexate) accentuating the utility of targeting essential gene products. However, the toxicity of traditional broad-based drugs to normal cells is high, limiting its utility. Thus, we seek to inactivate essential gene products by selectively delivering targeted biologic therapeutics, i.e. neutralizing monoclonal antibodies, against specific intracellular essential gene products thereby killing cancer cells. To selectively target tumors, we are employing tumor-associated protease “activatable” cell penetrating peptide (CPP) motif described by Tsein and co-workers. To demonstrate our novel approach, we are initially focusing on the intracellular delivery of RPA70 which is an essential gene product that functions in DNA replication and is found to be an attractive therapeutic target in breast and prostate cancers. Thus far, we synthesized a cell penetrating peptide (CPP) and a tumor-associated “activatable” CPP that can be conjugated to IgGs. We screened various bioconjugation techniques and found that thiolation of IgG with thiolane followed by incubation with CPP-maleimide was the most efficient with good CPP-to-antibody ratio. With these antibody bioconjugates, we are able to show that anti-RPA70 and control antibodies were taken up to the cytoplasm as well as into the nucleus of cells. Monitoring of cell growth and proliferation of cancer cell lines in the presence of CPP-anti-RPA70 are underway. Progress in these studies will also be presented.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3626. doi:10.1158/1538-7445.AM2011-3626
Abstract 3641: Breaking through the ceiling: A program to significantly increase efficacy in KRAS and BRAF mutant colorectal cancer xenograft tumors whose growth is arrested by Cetuximab + irinotecan therapy
Authors: Corcoran Erik , Pennello Anthony , Surguladze David , Paz Keren , Tonra James
Published: June 2012

Cetuximab has significant clinical benefits alone or in combination with irinotecan in metastatic colorectal cancer (mCRC) patients with KRAS wild type tumors, but efficacy in patients with KRAS mutant tumors has thus far been elusive. Mutant BRAF in mCRC tumors may also predict for reduced benefit with EGFR antibodies. Interestingly, in preclinical CRC models, cetuximab, alone or in combination with irinotecan, has significant efficacy in tumor models with mutant KRAS or BRAF. Here we examine if this preclinical efficacy can be significantly increased in a screen for add-on therapies that may provide clinically meaningful efficacy in mCRC patients requiring an EGFR antibody.

HT-29 (BRAF mutant-V600E) and HCT-116 (KRAS mutant-G38D) cell lines were utilized as models of CRC. We screened 14 compounds that could potentially add to the effects of cetuximab+irinotecan (C+I) treatment, including inhibitors of inflammation, enzymes, receptor tyrosine kinases, HSP90, cyclins, mTOR, an ATP mimetic, activators of apoptosis and PPARγ.

Of the compounds evaluated only 17-AAG (HSP90 inhibitor), everolimus(mTOR inhibitor) and DC101 (antibody targeting murine VEGFR2) significantly broke the ceiling of tumor stasis established with C+I treatment alone in both models. 17-AAG+C+I resulted in T/C% values of 14 and 32% in HCT-116 and HT-29, respectively, compared to 25 and 62% in the C+I treatment group. Follow up studies showed this benefit to be due to an additive interaction between 17-AAG and irinotecan, which was also associated with significant weight loss. Everolimus+C+I treatment resulted in a T/C% of 15 and 22% in HCT-116 and HT-29, respectively, compared to 22 and 35% in the C+I treatment group. The benefits of everolimus+C+I on the other hand required all three agents. The combination of DC101+C+I was significantly more efficacious than C+I in both models, with a T/C% of 11 and 33% in HCT-116 and HT-29, respectively, compared to 19 and 53% in C+I treatment group. In contrast to these three therapies, all other compounds evaluated did not improve the antitumor effects of C+I alone.

Results demonstrate a ceiling effect in CRC models with KRAS or BRAF gene mutations that may be associated with the limited clinical benefits observed with cetuximab in patients. The fact that this ceiling can be broken with everolimus in a manner that requires cetuximab, supports the potential utility of cetuximab in these patients in a combination approach.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3641. doi:10.1158/1538-7445.AM2011-3641
Abstract 3657: Upregulation of PD-1 and Tim-3 expression on tumor antigen-specific CD4+ T cells is associated with reversible T cell dysfunction in patients with advanced melanoma
Authors: Fourcade Julien , Sun Zhaojun , Guillaume Philippe , Luescher Immanuel F. , Sander Cindy , Kirkwood John M. , Kuchroo Vijay , Zarour Hassane M.
Published: June 2012

The paradoxical coexistence of spontaneous tumor antigen-specific immune T cell responses with progressive disease in cancer patients furthers the need to dissect the molecular pathways involved in tumor-induced T cell dysfunction and exhaustion. We have previously observed in patients with advanced melanoma that the cancer-germline antigen NY-ESO-1 stimulates spontaneous NY-ESO-1-specific CD8+ T cells that upregulate PD-1 expression and that a fraction of PD-1+ NY-ESO-1-specific CD8+ T cells upregulates Tim-3 expression. We have found that Tim-3+PD-1+ NY-ESO-1-specific CD8+ T cells represent highly dysfunctional T cells in terms of cytokine production and proliferation. Importantly, Tim-3/Tim-3L blockade together with PD-1/PD-L1 blockade enhanced cytokine production and proliferation of NY-ESO-1-specific CD8+ T cells upon prolonged antigen stimulation. Whether the upregulation of PD-1 and Tim-3 is associated with tumor antigen-specific CD4+ T cell dysfunction/exhaustion in patients with advanced melanoma remains unknown. Here, our findings show that in contrast to EBV-specific, CMV-specific and total CD4+ T cells, PD-1 and Tim-3 expression is upregulated by NY-ESO-1-specific CD4+ T cells isolated from peripheral blood lymphocytes of patients with advanced melanoma. Interestingly, PD-1/PD-L1 blockade synergized with Tim-3/Tim-3L pathway blockade to restore the numbers of cytokine-producing and proliferating NY-ESO-1-specific CD4+ T cells. Collectively, our findings support the use of Tim-3/Tim-3L blockade in association with PD-1/PD-L1 blockade to reverse tumor-induced CD8+ and CD4+ T cell exhaustion/dysfunction in patients with advanced melanoma. Our findings have significant implication in terms of novel immunotherapeutic strategies aiming at promoting T cell-mediated tumor regression in patients with advanced cancers.

This work was supported by NIH/NCI Grants CA90360 and CA112198 (HMZ) and Cancer Research Institute grant (HMZ).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3657. doi:10.1158/1538-7445.AM2011-3657
Abstract 3661: The impact of tumor-infiltrating natural killer cells on ovarian cancer progression
Authors: El-gazzar Ahmed , Eckelhart Eva , Perco Paul , Horvat Reinhard , Sexl Veronika , Krainer Michael
Published: June 2012

Cancers adopt diverse strategies to safeguard their survival by evading tumor surveillance. Natural killer (NK) cells and CD8 T-lymphocytes are capable of destroying tumor cells thus playing a critical role in tumor immunity. In previous studies, we showed that NK cell derived TRAIL is essential for the cytotoxic activity of the DR5 agonistic antibody AD5-10, since depletion of NK cells abolished the antitumor activity of AD5-10 in a xenograft ovarian cancer (OC) mouse model. In the present study, we investigated whether NK cells are associated with clinical outcome as well as with the immune infiltrate showing anti-tumor immunity in OC. We analyzed NK cell infiltration in human primary ovarian tumor tissues using immunohistochemical analysis of a representative population of OC patients on a tissue microarray. NK tumor-infiltrating cells were detected within tumor tissues, whereas CD3 tumor-infiltrating T-lymphocytes were almost undetectable. NK cells in addition inversely correlated with FIGO stage (r=−0.51, p<0.001) and tumor grade (r=−0.3, p=0.03). These data indicate that the presence of intratumoral NK cells correlates with improved clinical outcome in OC.

When we analyzed the cytotoxic capacity of human NK cells against OC cells in vitro, we found that human NK cells were capable to induce apoptosis in a concentration-and time-dependent manner in several OC cell lines. Interestingly, the addition of the DR5 agonistic antibody AD5-10 sensitized TRAIL resistant OC cell lines to NK cells mediated cytolysis.

To study tumor surveillance of OC in vivo, we are currently setting up mouse models. Transformed murine ovarian surface epithelial (MOSE) cell lines derived from C57BL/6 mice have been implanted intraperitoneally into syngenic wild type, RAG2 -/-, RAG2 -/- γ -/-, NK depleted, CD8 depleted C57BL/6 recipient mice. The outcome of these studies will be presented.

In summary, our findings point at a critical role for NK cell mediated tumor surveillance for OC development. Importantly, NK cell infiltration correlates with prognosis in human ovarian carcinoma. Thus, our study may open novel therapeutic opportunities by interfering with host immunity in the future.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3661. doi:10.1158/1538-7445.AM2011-3661
Abstract 3662: Absence of leukotriene B4 receptor-1 (BLT1) protects against lung cancer
Authors: Satpathy Shuchismita R. , Krishnan Elangovan , Sharma Rajesh K. , Jala Venkatakrishna R. , McGregor W. Glenn , Bodduluri Haribabu
Published: June 2012

Chemokines direct leukocyte trafficking, which plays a major role in immune and inflammatory responses, thus contributing to (or) modulating a number of disease conditions. During carcinogenesis leukocytes infiltrate the site of the tumor microenvironment and could exert a major influence on promotion or suppression of cancer depending on their activation status. Leukotriene B4, a pro-inflammatory lipid chemokine, mediates many of its activities through BLT1, a high affinity G-protein coupled receptor. BLT1 is expressed on an array of immune cells and has been implicated to play a critical role in many inflammatory diseases. We investigated whether BLT1 also influences lung carcinogenesis, the leading cause of cancer-related deaths worldwide. In this study, we used BLT1-deficient mice (BLT1-/-) to determine their susceptibility to lung cancer development in a transgenic model expressing an oncogenic form of K-ras (K-ras LA1) as well as in carcinogen (3-Methylcholanthrene; 3MCA)-induced and inflammation (butylated hydroxy toluene; BHT) – promoted murine lung cancer model. We found that in the activated K-ras transgenic background the BLT1-/- mice showed fewer and smaller lung tumors as compared to the BLT1+/+ mice. In the MCA-BHT induced lung cancer model also the BLT1-/- mice showed fewer and smaller lung tumors than the BLT1+/+ mice. Lung lesions in BLT1-/- mice were more of adenomatous hyperplasia type and fewer adenomas when compared to those in BLT1+/+ mice. Moreover, the frequency of induced mutations in cells derived from the lungs of BLT1-/- mice was greatly reduced compared to BLT1+/+ mice. Pulmonary inflammation was assessed in bronchoalveolar lavage (BAL) fluids following one, three or six weekly injections of BHT. At one and three week time points macrophages, and at six weeks lymphocytes constituted the predominant leukocyte subtypes in the BAL fluids of BLT1+/+ mice. In BLT1-/- mice both of these responses were significantly attenuated leading to an overall reduction in pulmonary inflammation. Based on these results, we conclude that BLT1 mediated pulmonary inflammation has a promoting role in lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3662. doi:10.1158/1538-7445.AM2011-3662
Abstract 3667: Reduction of in vivo tumor growth and angiogenesis by a humanized IgG4 monoclonal antibody to SEMA4D
Authors: Jonason Alan S. , Fisher Terrence L. , Torno Sebold , Bussler Holm , Winter Laurie A. , Kirk Renee , Howell Alan , Caplan Jeff , Kenney Patrick , Reilly Christine , Scrivens Maria , Huang He , Croy Leslie , Evans Elizabeth E. , Paris Mark , Watkins Raymond , Zauderer Maurice , Leonard John E. , Smith Ernest S.
Published: June 2012

Semaphorin 4D (SEMA4D; CD100) has been implicated in several key mechanisms of tumor progression, including neovascularization, tumor invasion, and metastasis. SEMA4D binding to its receptor plexin-B1 (PLXNB1) on endothelial cells transactivates MET and promotes formation of new blood vessels and tumor growth in vivo. SEMA4D is over-expressed in a wide array of tumor types, and is also produced by recruited inflammatory cells present in the tumor microenvironment. Several recent papers have shown that in an environment lacking SEMA4D, the ability of mouse cancer cells to originate tumor masses and metastases is severely impaired. Furthermore, SEMA4D produced by tumor-associated macrophages has been shown to support tumor angiogenesis and growth.

In addition to its effects on endothelial cells, SEMA4D has a direct effect on tumor invasive growth and migration. A recent clinical study in soft tissue sarcomas correlates strong SEMA4D expression in tumors with a higher mitotic count and poor prognosis. SEMA4D binding to PLXNB1 on tumor cells results in MET transactivation and migration of tumor cells. It has been further reported that overexpression of PLXNB1 and MET in breast and ovarian cancers is a negative prognostic factor. Tumors co-expressing PLXNB1 and MET were characterized as having a higher grade and an increased frequency of metastases.

Collectively, these results suggest that expression of SEMA4D, either by tumor cells or by tumor associated inflammatory cells, functions as a crucial factor in tumor neovascularization, and that expression of the SEMA4D and/ or its high affinity receptor in tumors may further induce tumor growth rate and metastatic potential.

Antibody neutralization of SEMA4D thus may represent a new therapeutic strategy for cancer treatment. We selected a humanized IgG4 antibody that binds with high affinity to rat, mouse, primate, and human SEMA4D, and utilized several in vitro functional assays to demonstrate that this antibody blocks SEMA4D – PLXNB1 interactions. Using syngeneic, xenograft and orthotopic tumor models we demonstrated that antibody mediated neutralization of SEMA4D in vivo inhibits tumor growth and tumor angiogenesis. This humanized antibody has successfully completed IND-enabling toxicology testing and we anticipate the initiation of human clinical trials in early 2011.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3667. doi:10.1158/1538-7445.AM2011-3667
Abstract 368: MUC1-targeted gold nanoparticle-based theranostic approach
Authors: Danysh Brian P. , Constantinou Pamela E. , Lukianova-Hleb Ekaterina , Broaddus Russell , Carson Daniel D.
Published: June 2012

MUC1 is a large transmembrane glycoprotein, extending 200-400 nm from the apical surface of normal polarized epithelial cells in a variety of mucosal tissues. The large ectodomain contains a series of heavily glycosylated tandem repeats and serves as a protective barrier to enzymatic degradation and microbial attack, as well as prevents embryo attachment during the non-receptive phase in the uterus. Many cancers, including endometrial carcinomas, overexpress MUC1 which is believed to promote tumor progression by protecting tumor cells from the immune system, inhibiting apoptosis, and increasing resistance to various chemotherapeutic agents. The availability of MUC1 glycoform-specific antibodies creates an opportunity to exploit the increased or aberrant MUC1 expression in carcinoma cells by creating MUC1-targeted therapies. Gold nanoparticles (AuNPs) conjugated to a human MUC1 ectodomain specific antibody (214D4) are readily endocytosed by MUC1 expressing human endometrial cells (HES) in vitro and, following exposure to a short laser pulse, can be used to form transient vapor bubbles (plasmonic nanobubbles) capable of destroying a cell by mechanically disrupting the cell membrane. In this work, we compare the selective targeting capabilities of MUC1-targeted AuNPs using the human endometrial epithelial cell line HES and endometrial carcinoma cell lines HEC1A and HEC1B. In addition, we have used human MUC1-expressing transgenic mouse lines to examine the feasibility of using AuNP-214D4 targeting in mouse endometrium. These results demonstrate the potential use of MUC1-targetted AuNPs to detect and destroy, as well as deliver cargo, to MUC1 expressing tumors. (Supported by NIH grants HD29963 to DDC, and MD Anderson Gynecologic SPORE for Uterine Cancers 2 P50 CA098258-06 to DDC and RB).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 368. doi:10.1158/1538-7445.AM2011-368
Abstract 3685: C-Jun modulates alcohol-induced RNA Pol III-dependent transcription through Brf1 and TBP pathway
Authors: Zhang Qingsong , Evans Austin G. , Levy Daniel , Zhong Shuping
Published: June 2012

Cancer cells have a consistent cytological feature of nucleolar hypertrophy, enlarged nucleoli, where RNA polymerase III genes (Pol III genes) are transcripted. This implies that transformation in situ is closely linked to the deregulation of Pol III gene transcription, because the size of the nucleolus reflects the levels of rRNA synthesis. Deregulation of Pol III genes is tightly associated cell transformation and tumorgenesis. However, very little is known about whether alcohol consumption affects Pol III gene transcription. By using cell culture model and animal model, we have found, for the first time that alcohol induces Pol III gene transcription in JNK1 and ADH dependent manner. Alcohol increases c-Jun expression in HepG2-ADH cells. To determine whether the alcohol-mediated increases c-jun required to stimulate TBP and Brf1 expression are due to enhance occupancy of c-jun at their promoters, chromatin immunoprecipitation (ChIP) assays were performed. Ethanol induces a marked increase in the recruitment of c-jun to the TBP promoter, while a modest increase in the occupancy of both c-fos and Elk-1 was observed. These results support the idea that alcohol mediates an increase in TBP expression primarily through enhanced expression of c-jun and its recruitment to the TBP promoter. Sequence analysis reveals both putative AP-1 and Elk-1 binding sites in regions 5’ of the transcription start site of the Brf1 gene. ChIP analysis reveals that ethanol induces an increase in the occupancy of c-jun to the region containing an AP-1 binding site, while no significant increase in binding of Elk-1 to the Elk-1 binding site is observed. Interestingly, c-jun, c-fos and Elk-1 are also found to occupy the tRNALeu gene. Upon ethanol treatment, an increase in TBP recruitment to the tRNALeu gene is observed, as well as a marked increase in the occupancy of c-jun. However, alcohol does not induce any apparent change in recruitment of either c-fos or Elk-1 to the tRNA gene. These results suggest that c-jun may function directly at sequences near tRNA genes to induce transcription. Together, these results support the idea that alcohol enhances expression of TBP, Brf1, and tRNA gene by facilitating c-jun recruitment to these promoters.

*: This project was supported by NIH grant AA017288 to S.Z.

**: Corresponding author: szhong@usc.edu. Tel: 626-628-7693 or 323-442-114

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3685. doi:10.1158/1538-7445.AM2011-3685
Abstract 3688: Role of inhibitor of apoptosis family proteins in diallyl trisulfide-induced apoptotic cell death in human prostate cancer cells
Authors: Bommareddy Ajay , Kim Su Hyeong , Singh Shivendra V.
Published: June 2012

Diallyl trisulfide (DATS) is a promising cancer chemopreventive constituent of processed garlic. The DATS administration not only inhibits chemical carcinogenesis in experimental rodents but also affords significant protection against cancer development in a transgenic mouse model of prostate cancer. We have shown previously that DATS inhibits growth of human prostate cancer cells by causing apoptosis, but the mechanism of cell death is not fully understood. Inhibitor of apoptosis (IAP) family proteins has emerged as critical regulators of apoptosis. In this study, we investigated the role of IAP family proteins in DATS-mediated apoptosis using PC-3 (an androgen-independent cell line lacking functional p53) and LNCaP (an androgen-responsive cell line with wild-type p53) human prostate cancer cells as a model. Protein level of X-linked inhibitor of apoptosis (XIAP) was decreased markedly upon 8-hour treatment with 20 and 40 µmol/L DATS in both PC-3 and LNCaP cells but this effect was somewhat reversible at the 16-hour time point. The DATS-mediated suppression of XIAP protein was not due to a decrease in its mRNA expression. Instead, the DATS-mediated decline in XIAP protein level was reversed in the presence of proteasomal inhibitor MG132. Ectopic expression of XIAP in PC-3 cells conferred modest yet statistically significant protection against DATS-induced apoptosis. Interestingly, the DATS treatment resulted in a marked and sustained induction of survivin protein in both cell types. The DATS-mediated induction of survivin protein correlated with an increase in its mRNA levels in PC-3 and LNCaP cells. RNA interference of survivin resulted in increased apoptosis even in absence of DATS treatment in PC-3 cells. However, the DATS-induced apoptosis was only marginally affected by siRNA knockdown of survivin. Inhibition of prostate cancer development in Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) mice by p.o. gavage with DATS correlated with a statistically significant decrease in the levels of XIAP protein and induction of survivin protein expression. The results of the present study indicate differential effect of DATS treatment on IAP family protein expression, which may serve as biomarkers of DATS response. This study was supported by the USPHS grant 2 RO1 CA113363-06, awarded by the National Cancer Institute.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3688. doi:10.1158/1538-7445.AM2011-3688
Abstract 3692: Allyl isothiocyanate arrests bladder cancer cells in mitosis, and mitotic arrest in turn leads to apoptosis via Bcl-2 phosphorylation
Authors: Geng Feng , Tang Li , Zhang Yuesheng
Published: June 2012

Allyl isothiocyanate (AITC) occurs in many common cruciferous vegetables, and was recently shown to be selectively delivered to bladder cancer tissues through urinary excretion and to inhibit bladder cancer development in an orthotopic rat bladder cancer model. Here, we show that AITC arrests human bladder cancer cells in mitosis and induces apoptosis. Mitotic arrest by AITC was associated with significant down regulation of both α-tubulin and β-tubulin which are essential for mitosis. AITC also induced mitochondria-mediated apoptosis, including cytochrome c release from mitochondria to cytoplasm, cleavage of caspase-9 and caspase-3, cleavage of poly (ADP-ribose) polymerase (PARP) and lamin B1, and formation of TUNEL-positive cells. Both a general caspase inhibitor (Z-VAD-FMK) and a caspase-9 inhibitor (Z-LEHD-FMK) attenuated AITC-induced apoptosis. Moreover, we found that apoptosis induction by AITC resulted from mitotic arrest and was mediated via Bcl-2 phosphorylation at Ser70. Thus, AITC-induced mitotic arrest was accompanied by a strong Bcl-2 phosphorylation, while Bcl-2 expression was not affected. Pre-arresting cells in G1 phase using hydroxyurea abrogated both mitotic arrest and Bcl-2 phosphorylation in cells treated with AITC. Overexpression of a Bcl-2 mutant (loop domain deleted, removing Ser70) prevented AITC from inducing apoptosis. AITC-induced Bcl-2 phosphorylation appears to be mediated by c-Jun N-terminal kinase (JNK), as AITC activated JNK but a JNK inhibitor (SP600125) abolished Bcl-2 phosphorylation in AITC-treated cells. In summary, AITC is a highly promising agent for bladder cancer prevention and treatment, and the present study reveals a novel anticancer mechanism of AITC in human bladder cancer cell.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3692. doi:10.1158/1538-7445.AM2011-3692
Abstract 3694: Activation of ASK1 by capsaicin mediates apoptosis in pancreatic cancer cells
Authors: Pramanik Kartick C. , Srivastava Sanjay K.
Published: June 2012

Apoptosis signal-regulating kinase 1 (ASK1), a member of the mitogen-activated protein kinase (MAPK) kinase kinase family plays an essential role in reactive oxygen species (ROS) induced cellular response. Thioredoxin (Trx), a redox sensitive protein binds to ASK1 and inhibits its activation. In our previous study, we have shown that capsaicin induced apoptosis in pancreatic cancer cells was associated with the generation of ROS and persistent disruption of mitochondrial membrane potential. In the present study, we evaluated the interaction of thioredoxin/ASK1 in pancreatic cancer cells. In a concentration dependent study, we observed that capsaicin treatment down regulated thioredoxin and increased the phosphorylation (activation) of ASK1 at Thr845 in AsPC-1 and BxPC-3 cells. ASK1 has been shown to activate JNK, which in turn activates MKK4/7 resulting in the cleavage of caspase-9, and caspase-3. In agreement, our results reveal that capsaicin treatment activated JNK, MKK4/7, caspase-9 and caspase-3. Interestingly, treatment of cells with antioxidants such as tiron or catalase blocked the activation of ASK1 cascade by capsaicin and protected the cells from apoptosis indicating the involvement of ROS in the activation of ASK1. To confirm the interaction of Trx/ASK1 and the dissociation of ASK1 by capsaicin in our model, BxPC-3 cell were transiently transfected with contructs encoding ASK1 fused to C-terminal hemaggutinin (HA) and flag tagged Trx. Our results reveal that Trx over expression suppressed the effects of capsaicin whereas ASK1 over expression enhanced the apoptosis-inducing effects of capsaicin. Taken together, our results suggest that ROS generated by capsaicin reduce Trx expression resulting in the activation of ASK1 and downstream effectors leading to apoptosis in pancreatic cancer cells. [Supported in part by R01 grants CA106953 and CA129038 (to S.K.S) awarded by the National Cancer Institute].

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3694. doi:10.1158/1538-7445.AM2011-3694
Abstract 3732: Inflammatory breast cancer rates among different ethnic and racial groups in the United States
Authors: Reihani Sharareh , Akushevich Igor , Schildkraut Joellen , Il'yasova Dora
Published: June 2012

Inflammatory breast cancer (IBC) is considered to be the most aggressive form of breast cancer. In the US, the proportion of incidences of IBC cases ranges from 2% to 5%. Understanding the determinants of IBC rates among different populations may help to design prevention strategies. Internationally, IBC rates have been linked to socioeconomic status (SES). In the US, the analysis of the National Cancer Institute Surveillance Epidemiology and End Results (SEER) data for the period of 1988-2000, and data for 1994-1998 from the North American Association of Central Cancer Registries demonstrated greater IBC rates among Blacks compared to Whites and similar rates among Whites and Hispanics. However, the Hispanic population in the US has grown significantly in the last decade and its SES status is generally lower compared to non-Hispanic Whites. Therefore, we hypothesized that IBC rates in Hispanics have increased since the reported rates from 1994-1998 and are higher than among Whites.

We used the SEER database to estimate age-adjusted and age-specific rates of IBC among ages 20-84 in three racial/ethnic groups: Whites, Blacks, and Hispanics (including both Whites and Blacks). IBC cases were categorized using Common Stage Extension Codes 71-73. Age-specific IBC rates were estimated for three age-groups: 20-45 (pre-menopausal), 45-60 (peri-menopausal), and 60-84 (post-menopausal).

During 2004-2007, a total of 3107 IBC cases were diagnosed among the 20-84 year old population covered by the SEER registries. Among them, 2436 cases were diagnosed in Whites, 470 in Blacks, and 403 in Hispanics. Age-adjusted rates among Blacks were ∼ 1.4-fold greater than in Whites, whereas rates among Hispanics were ∼1.4-fold lower than Whites and ∼2-fold lower than Blacks. Age-specific rates among Blacks were greater than among Whites at all ages. Age-specific rates among Hispanics in pre- and peri-menopausal groups were similar to Whites, but became lower after menopause, which could account for overall lower age-adjusted rates among Hispanics.

In summary, our analysis indicates different IBC rates in Whites, Blacks, and Hispanics. New information about lower IBC rates among Hispanics poses a question of what accounts for these differences. Further investigations of the ethnic/racial rates disparities may elucidate the underlying risk factors for IBC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3732. doi:10.1158/1538-7445.AM2011-3732
Abstract 3735: Mathematical modeling of the inflammatory breast cancer age-patterns indicates its unique biology
Authors: Il'yasova Dora , Akushevich Igor , Siamakpour-Reihani Sharareh , Spector Neil , Schildkraut Joellen
Published: June 2012

Introduction: Inflammatory breast cancer (IBC) is the most fatal form of breast cancer (BC) with unknown etiology. IBC is characterized by rapid onset (3-6 month) with unusual clinical presentation (redness, edema, warmth, and pain), sometimes without an underlying tumor mass, whereas non-inflammatory BC most often presents as painless breast mass. IBC also presents with higher nuclear grade, more frequent involvement of lymph nodes, and negative hormone receptor status than non-inflammatory locally-advanced BC (NI-LABC). Finally, the incidence age-pattern of IBC has been shown to be distinctly different from NI-LABC. The differences in the cancer incidence age-patterns, as hypothesized by Armitage and Doll, reflect different number of successive cellular transitions necessary for the development of a clinically significant malignancy. We used extended Armitage-Doll model and SEER data for 2004-2007 to describe age-patterns of IBC and NI-LABC incidence and to estimate the number of cellular transitions involved in the development of these two BC types. Also, it was important to compare earlier described IBC age-patterns to the most recent as coding of IBC has been changed since 2004.

Methods: Using SEER data for 2004-2007, we estimated age-specific incidence rates of IBC and NI-LABC for ages 20-84. IBC cases were defined as having Common Stage Extension Codes 71-73. Incidence rates were modeled using extended Armitage-Doll model with four parameters reflecting the baseline hazard, the number cellular transitions, and properties of the distribution of individual predisposition.

Results and Conclusions: As expected, IBC incidence age-pattern was distinctly different from that of NI-LABC and similar to the earlier described by Hance et al. Specifically, the IBC incidence increased with age and peaked between ages 50 and 60 with obvious deceleration after 60. In contrast, NI-LABC incidence continued to increase after 50 years of age without a peak or deceleration. The number of estimated cellular transitions was ∼7 for IBC and ∼ 9 for NI-LABC; this difference in cellular transition number was statistically significant. In theory, each transition represents a distinct stage with a rate-limiting event. We discuss different interpretations of the lower transition steps estimated for IBC in light of its unique presentation and age-pattern. Finally, the similarity of age-patterns with the previously published analysis of SEER data confirms the validity the new definition of IBC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3735. doi:10.1158/1538-7445.AM2011-3735
Abstract 3740: Low carbohydrate diets, DASH-style diet and risk of post-menopausal breast cancer
Authors: Fung Teresa , Hu Frank , Hankinson Susan , Willett Walter , Holmes Michelle
Published: June 2012

Background: Low carbohydrate diets and the DASH-style diet have not been evaluated for their association with breast cancer.

Methods: We prospectively examined the association between the DASH score, overall, animal, and vegetable low carbohydrate diet scores and risk of postmenopausal breast cancer in 86,621 women in the Nurses’ Health Study. Diet scores were calculated from up to 7 food frequency questionnaires (FFQ) during up to 26 years of follow-up. We also examined the association with major plant food groups. Analysis was separately conducted for estrogen receptor status (ER) positive and negative tumors.

Results: We ascertained 5,522 incident cases of breast cancer, including 3,314 ER+ and 826 ER- cancers. After adjusting for potential confounders, the DASH score was associated with a lower risk of ER- cancer (RR comparing extreme quintiles=0.80, 95% CI=0.64-1.01, p trend=0.02). However, this is largely explained by higher fruits and vegetables intake. An inverse association was also observed with the vegetable low carbohydrate score (corresponding RR=0.81, 95% CI=0.65-1.01, p trend=0.03). Total fruits and low protein vegetables were association with a lower risk of ER- cancer (RR comparing extreme quintiles=0.71, 95%CI=0.55-0.90, p trend=0.005).

Conclusion: A diet high in fruits and vegetables, such as one represented by the DASH score was associated with a lower risk of ER- breast cancer. In addition, a diet high in plant protein and fat and moderate in carbohydrate content is also associated with a lower risk of ER- cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3740. doi:10.1158/1538-7445.AM2011-3740
Abstract 3745: IL-10 polymorphisms, smoking, and Helicobacter pylori infection on the risk of noncardia gastric cancer in Koreans
Authors: Kim Jeongseon , Cho Young Ae , Shin Aesun , Cho Soo-Jeong , Kim Chan Gyoo , Lee Jong Yeul , Kim Young-Woo , Choi Il-Ju
Published: June 2012

Background: Genetic variations of interleukin-10 (IL-10) and environmental factors are assumed to influence inflammation and gastric carcinogenesis. Therefore, we aimed to investigate the association between IL-10 polymorphisms, smoking, and Helicobacter pylori (H. pylori) infection on the noncardia gastric carcinogenesis in Koreans.

Methods: We genotyped 3 promoter polymorphisms (−1082 A>G, -819T>C, -592A>C) on the IL-10 gene in 495 noncardia gastric cancer patients and 495 sex- and age-matched controls. Multiple logistic regression models were used to detect the effects of IL-10 genetic variants, smoking, and H. pylori infection on gastric cancer risk, stratified by histological type of gastric cancer.

Results: The IL-10-819C allele and -592C allele are in complete linkage disequilibrium, and IL-10-819C/-592C carriers are associated with a higher risk of noncardia gastric cancer, particularly with a risk of intestinal type cancer (OR [95% CI] = 1.50 [1.08−2.08]), than those with the wild type homozygote genotypes. Compared to nonsmokers carrying the wild type homozygotes, current smokers carrying IL-10-1082G and -819C/-592C showed 4.91 (95% CI = 2.49−9.69) and 6.82 (95% CI = 2.94−15.84) times increased risk of intestinal type gastric cancer, respectively. In addition, smokers with H. pylori infection were in the highest risk of intestinal gastric cancer compared with non-smokers without H. pylori infection, and this association was particularly stronger among IL-10-1082G carriers than AA carriers (OR [95% CI] = 15.54 [5.52−43.72]).

Conclusion: Inflammation-related genetic variants may interact with smoking and H. pylori infection on the risk of noncardia gastric cancer, particularly intestinal type. Therefore, high risk group may reduce the risk of gastric cancer by modifying their lifestyles.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3745. doi:10.1158/1538-7445.AM2011-3745
Abstract 3749: Polymorphisms in metabolism genes may mediate the effect of dietary intake on pancreatic cancer risk
Authors: Jansen Rick , Robinson Dennis , Stolzenberg-Solomon Rachael , Bamlet William , Cunningham Julie , Rider David , Oberg Ann , Hammer Traci , Rabi Kari , Anderson Kristin , Olson Janet , Sinha Rashmi , Petersen Gloria
Published: June 2012

Background: The role of dietary fruit, vegetable, fiber, and whole grain intake is implicated as a potential protective factor against pancreatic cancer, but studies are inconsistent. A possible explanation for the variability is that individuals who carry constitutional metabolism gene variants (minor alleles) may differentially benefit compared to those who are homozygous for the major allele, which over a life-time could lead to altered pancreatic cancer risk. Methods: We genotyped 70 SNPs that tag ten candidate metabolism genes (CAT, GAA, GCK, MT1E, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT2B4, and UGT2B7) involved in the metabolism of components of fruits, vegetables, fibers, and whole grains to test if differential associations exist with pancreatic adenocarcinoma. We used a clinic-based case-control design, excluding participants who reported changing their diet within 5 years prior to entering the study. Three hundred eighty-four rapidly ascertained cases and nine hundred eighty-three non-cases from a primary care clinic (frequency matched on age at recruitment (+ 5 years), race, sex, and region of residence) provided blood samples for DNA and completed epidemiologic surveys plus a 144-item food frequency questionnaire developed by the National Cancer Institute. We used a dominant model to code SNPs and split dietary intake categories based on the sex-specific median intake level among non-cases. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals, adjusted for age, sex, family-history of pancreatic cancer, smoking (never/ former/ current), body mass index, energy intake, and alcohol consumption. The reference group was defined as carriers of no minor alleles in the lowest intake category. Results: The greatest benefit was observed for carriers of no minor alleles, for rs11032702 (CAT) with higher insoluble dietary fiber intake (OR [95%CI]: 0.515 [0.37, 0.71]); for rs735670 (GCK) with higher soluble dietary intake (0.473 [0.34, 0.67]); for rs2070971 (GCK) and rs2268569 (GCK) with higher fruit intake not from citrus, melon, and berries (0.513 [0.36, 0.73] and 0.554 [0.40, 0.78]); and for rs17832252 (GCK) with higher whole grain intake (0.530 [0.37, 0.76]); all comparisons had a reference group of no minor alleles with low dietary intake and a p-value for interaction <0.001. Conclusions: Inter-individual variation in metabolism of fruits, vegetables, fiber, and whole grain via metabolism gene variants may influence pancreatic cancer risk.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3749. doi:10.1158/1538-7445.AM2011-3749
Abstract 3776: Bone marrow stromal cell paracrine signaling and IL-6 induce autophagy in bone metastatic prostate cancer cells
Authors: Delk Nikki A. , Farach-Carson Mary C.
Published: June 2012

Prostate cancer (PCa) is the second leading cause of death in North American men, where 80% of PCa mortality is due to bone metastasis. It is imperative to understand the biology of PCa cells in bone, especially as related to the role of the microenvironment in cellular adapation. Our lab recently published data revealing that bone marrow stromal cell (BMSC) paracrine signaling induces apoptosis in co-cultured bone metastatic PCa cells. However, a subpopulation of the bone metastatic PCa cells can avoid apoptotic cell death and undergo neuroendocrine differentiation (NED), a phenotype that contributes to tumor growth and is correlated with poor prognosis. One process that mediates cell survival and differentiation is autophagy, a process of sequestering cytoplasmic components for degradation and recycling to maintain cellular homeostasis. Autophagy provides a long term survival and growth advantage for cancer cells by relieving metabolic stress. Neuronal differentiation with cytoplasmic reduction is one adaptive response that can involve autophagy. Thus, we hypothesize that autophagy is a cytoprotective mechanism for PCa cell survival and NED in the bone microenvironment. To address this, we assessed the paracrine effect of BMSC on bone metastatic PCa cell autophagy and identified interleukin-6 (IL-6) as a BMSC paracrine factor that can induce PCa autophagy. We provide experimental data showing that IL-6 can protect PCa cells from apoptosis and simultaneously induce PCa NED. Current experiments are underway to determine if IL-6-induced autophagy functions upstream of bone metastatic PCa cell survival and NED and to dissect the IL-6 signaling pathway responsible for autophagy induction in PCa cells. These studies will identify IL-6 pathway components as molecular targets to attenuate cytoprotective autophagy in PCa cells in the bone microenvironment, providing new avenues for long term treatment of bone lesions in PCa patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3776. doi:10.1158/1538-7445.AM2011-3776