bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4533: Interaction between androgen receptor and its corepressor SLIRP is regulated by Ack1 tyrosine kinase
Authors: Zhang Zhentao , De Silva Dinuka , Liu Yuanbo , Earp H. Shelton , Whang Young E.
Published: June 2012

Reactivation of androgen receptor (AR) is critical to castration resistant progression of prostate cancer. We previously demonstrated that Ack1 (activated cdc42-associated kinase) promotes growth of prostate xenograft tumors in castrated animals by activation of AR through phosphorylation of the Tyr-267 site. However, the molecular mechanisms underlying activation of AR by Ack1 need to be fully elucidated. Using the proteomics-based approach of Differential In-Gel Electrophoresis, we searched for proteins whose interaction with AR was regulated by Ack1 by characterizing proteins coimmunoprecipitating with AR in transfected 293T cells in the absence or in the presence of activated Ack1 kinase. SLIRP (SRA stem-loop interacting RNA binding protein) was identified as a candidate protein. We confirmed that the interaction between AR and SLIRP is abrogated by Ack1 expression and dihydrotestosterone (DHT) in 293T cells and in LNCaP prostate cancer cells. Additionally, treatment with heregulin, a ligand activating HER-2/HER-3 and Ack1 downstream, also led to dissociation of AR and SLIRP in LNCaP cells. Tyrosine kinase activity of Ack1 was shown to be required for its ability to dissociate AR and SLIRP through the use of a kinase-dead mutant in 293T cells and the use of an Ack1 inhibitor dasatinib in LNCaP cells treated with heregulin. However, disruption of interaction between AR and SLIRP by Ack1 cannot be attributed to any known AR tyrosine phosphorylation sites since Ack1 expression led to disruption of binding between SLIRP and AR Y267F, Y363F, and Y534F mutants. Since SLIRP does not contain tyrosine residues, the substrate of Ack1 involved in AR-SLIRP dissociation is not known yet. We showed that SLIRP functions as a physiologically relevant corepressor of AR in prostate cancer cells. Chromatin immunoprecipitation analysis demonstrated that SLIRP was bound to the androgen regulated enhancers of AR target genes in the absence of androgen and that androgen or heregulin treatment led to loss of SLIRP binding at the androgen regulated enhancers. AR-dependent reporter activity was inhibited by overexpression of SLIRP and was increased by SLIRP knockdown. SLIRP knockdown also increased the expression of endogenous AR target mRNA levels of PSA and hK2. In summary, our data suggest that Ack1 kinase inhibits the interaction between AR and the SLIRP corepressor and causes dissociation of SLIRP from the AR target gene enhancers and thereby enhance AR transcriptional activity.

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 4533. doi:10.1158/1538-7445.AM2011-4533
Abstract 4534: Lung cancer epidermal growth factor receptors are transactivated by neurotensin
Authors: Moody Terry W. , Osefo Nauramy , Sancho Veronica , DiFlorio Alessia , Mantey Samuel , Jensen Robert T.
Published: June 2012

Neurotensin (NT) is an autocrine growth factor for some lung cancer cells (Moody et al., Life Sci 36:1727(1985)). The NTS1 receptor (R), which causes phosphatidylinositol turnover, elevates cytosolic Ca2+ and increases proliferation of lung cancer cells, is blocked by SR48692 (Moody et al., Peptides 22:109 (2001)). Previously we found that NT caused tyrosine phosphorylation of focal adhesion kinase in non-small cell lung cancer (NSCLC) cells (Leyton et al., Eur. J. Pharm. 442:179 (2002)). Here the ability of NT to cause tyrosine phosphorylation of the epidermal growth factor (EGF)R in lung cancer cells was investigated. NT and NT8-13 but not NT1-8 caused tyrosine phosphorylation of the EGFR using NCI-H1299 or H345 cells. The transactivation of the EGFR caused by NT addition to lung cancer cells was inhibited by SR48692 (NTS1R antagonist) or gefitinib (EGFR tyrosine kinase inhibitor). NT significantly increased EGFR tyrosine phosphorylation (4-fold) after 0.5 min in a dose-dependent manner. The ability of NT to increase EGFR or ERK tyrosine phosphorylation was inhibited by PP2 (Src inhibitor), GM6001 (matrix metalloprotease inhibitor), or antibody to transforming growth factor (TGF) α. By ELISA, NT stimulated significantly the release of TGFα from NCI-H838 cells. NT stimulation of EGFR tyrosine phosphorylation was inhibited by addition of N-acetylcysteine (anti-oxidant), tiron (superoxide scavenger), DPI (NADPH oxidase inhibitor). These results indicate that NT causes transactivation of lung cancer EGFR in an oxygen-dependent, Src-dependent manner resulting in activation of matrix metalloprotease and release of TGFα.

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 4534. doi:10.1158/1538-7445.AM2011-4534
Abstract 4538: Small ubiquitin-related modifier-1 (SUMO-1) modification of retinoic acid receptor α (RARα) regulates its nuclear localization and metabolic stability
Authors: Fang Yanfen , Zhang Lei , Yan Yan , Yang Bo , He Qiaojun
Published: June 2012

Retinoic acid receptor α (RARα) has been demonstrated to be one of the most important retinoic acid receptors through which all-trans retinoic acid (ATRA) exerts its biologic effects on differentiation of leukemic cells. Previous studies have demonstrated that RARα is subject to several post-translational modifications that regulate its functions, including phosphorylation and ubiquitination. Here we are the first to show a small ubiquitin-related modifier-1 (SUMO-1) modification of RARα, and this modification might play an essential role in ATRA-induced differentiation of acute myeloid leukemia cells (HL60 and NB4) and osteosarcoma cells (U2OS). We found that SUMO-1 covalently modified RARα both in vivo and in vitro, and lysine 399 is the modification site as mutation of lysine 399 to arginine in RARα completely abolished the conjugation of SUMO-1 to RARα. We then observed that covalent modification by SUMO-1 led to the nuclear localization of RARα after ATRA treatment. Either mutation of RARα at lysine 399 or silencing of SUMO-1 could significantly block ATRA-induced RARα nuclear localization. We further found that SUMO-1 also regulated the functions of RARα by controlling RARα metabolic stability. The conjugation of ubiquitin to RARα was markedly enhanced when the lysine 399 site of RARα was mutated into arginine. Moreover, the half-life of the wild type RARα was much longer (approximate 3-fold) than the lysine 399 mutant form. These two lines of evidence indicated that SUMO-1 modification protected RARα from ubiquitin-dependent degradation. Furthermore, we observed that RARα with the deficient of SUMO-1 modification could not exert its function to regulate ATRA-induced differentiation of leukemia cells and osteosarcoma cells, which was evidenced by the decreased expression of the differentiation markers. Taken together, our data presented for the first time that sumoylation of RARα proteins at lysine 399 by SUMO-1 contributed to the nuclear localization and stability of the nuclear receptor, which might facilitate the ATRA signal transduction. Our study reveals a novel molecular mechanism for the regulation of RARα in ATRA-induced differentiation of tumor cells.

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 4538. doi:10.1158/1538-7445.AM2011-4538
Abstract 454: Targeting macrophages in a preclinical model of malignant mesothelioma
Authors: Blakely Collin M. , Kolhatkar Nikita , Johansson Magnus , Beltran Adam , Barbone Dario , Bueno Raphael , Sugarbaker David , Jahan Thierry , Jablons David , Broaddus V. Courtney , Coussens Lisa M.
Published: June 2012

Malignant pleural mesothelioma (MPM) is a debilitating, incurable cancer that exhibits a high degree of resistance to standard chemotherapy; thus, we sought to identify novel therapeutic targets for treatment. In the vast majority of cases, MPM is associated with exposure to asbestos fibers, which result in a chronic pro-inflammatory state. As such, we hypothesized that MPMs were infiltrated by leukocytes possessing tumor-potentiating activities. To address this, we evaluated MPMs, resected from 26 patients, by flow cytometry and found that tumors were highly infiltrated with macrophages (31 ± 4.6% of total CD45+), a percentage that is significantly higher that that observed in other thoracic malignancies (NSCLC cancer, 9%; esophageal, 4%). Since recent experimental data has revealed that tumor-associated macrophages (TAMs) secrete proangiogenic, prosurvival, and proinvasive factors that foster tumor progression, we evaluated macrophage-depletion in MPM as a novel therapeutic strategy. Using a syngeneic murine transplantation model and liposomal-encapsulated clodronate that efficiently deplete phagocytic macrophages, as monotherapy, and in combination with chemotherapy, we revealed a significant decrease in tumor growth and a decrease in tumor-burden in tumor-bearing mice depleted of macrophages. Furthermore, when macrophage-depletion was combined with the cytotoxic agents gemcitabine and TRAIL, an even greater reduction in tumor burden was observed as compared to mice treated with either agent alone. These studies indicate that: 1) mesothelioma-associated macrophages provide a protumor function, and 2) depletion of mesothelioma-associated macrophages may improve efficacy of cytotoxic chemotherapy. Ongoing studies to reveal the effect of macrophage-depletion plus chemotherapy in limiting MPM development in NF2ko/+ mice exposed to asbestos are underway.

This work was supported by an NIH T32 training grant to Dr. Blakely, and by a DoD Mesothelioma Program grant (PR080717) to Drs. Broaddus and Coussens.

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 454. doi:10.1158/1538-7445.AM2011-454
Abstract 4543: Nuclear receptor estrogen-related receptor alpha promotes hypoxic growth prostate cancer cells
Authors: Zou Chang , Yu Shan , Yew David T. , Chan Franky L.
Published: June 2012

Estrogen-related receptors (ERRα,β,γ) which share significant homology with estrogen receptors, are orphan nuclear receptors and constitutively transactivated without estrogen-binding. Among the three subtypes, ERRα has been characterized to play a pivotal role in diverse aspects of energy homeostasis, including oxidative phosphorylation and mitochondrial biogenesis, via its transcriptional regulation of target genes. Expression studies in clinical tumor tissues show that ERRα expression is positively associated with a few hormone-dependent cancers, including breast, ovarian and endometrial cancers, and has been proposed to be useful as a prognostic marker for these cancers. We have previously reported that ERRα displays a ubiquitous expression pattern in various prostatic cell lines and an apparent elevated expression in high grade prostate cancer. However, its exact functional roles and prognostic value in prostate cancer still remains unclear. In this study, we analyzed the functional significance of ERRα in prostate cancer cell growth regulation by its stable expression in a hormone-sensitive prostate cancer cell line LNCaP. Our results showed that stable expression of ERRα in LNCaP cells could enhance their in vitro cell proliferation, adhesion to fibronectin, invasion and colony formation capacities of LNCaP cells under both normoxia and hypoxia condition (1% O2), while such in vitro growth phenotypes could be suppressed by an ERRα specific antagonist XCT790, suggesting that ERRα-induced growth phenotypes were ERRα specific. Moreover, under hypoxia condition, stable ERRα over-expression could stabilize HIF1α protein, up-regulate VEGF expression with an ERRα dose dependent pattern.

Taken together, our results showed that ERRα over expression promotes hypoxic growth of prostate cancer cells.

(This study is supported by a RGC General Research Fund CUHK461009)

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 4543. doi:10.1158/1538-7445.AM2011-4543
Abstract 4544: The induction of KLF5 transcription factor by progesterone contributes to progesterone-induced breast cancer cell proliferation and de-differentiation
Authors: Liu Rong , Zhao Dong , Zhou Zhongmei , Chen Ceshi
Published: June 2012

Progesterone (Pg) promotes normal breast development during pregnancy and lactation and increases the risk of developing basal-type invasive breast cancer. However, the mechanism of action of Pg has not been fully understood. In this study, we demonstrate that the mRNA and protein expression of Klf5, a pro-proliferation and pro-survival transcription factor in breast cancer, was dramatically up-regulated in mouse pregnant and lactating mammary glands. Pg, but not estrogen and prolactin, induced the expression of KLF5 in multiple Pg receptor (PR)-positive breast cancer cell lines. Pg induced the KLF5 transcription is through PR in the PR-positive T47D breast cancer cells. Importantly, Pg failed to promote T47D cell proliferation when the KLF5 induction was blocked by siRNA. In addition, KLF5 overexpression was sufficient to induce the cytokeratin 5 (CK5) expression and the induction of CK5 by Pg was partially abrogated by KLF5 siRNA. Consistently, the expression of KLF5 was positively correlated with that of CK5 in a panel of breast cancer cell lines. Taken together, we conclude that KLF5 is a Pg-induced gene that contributes to Pg-mediated breast epithelial cell proliferation and de-differentiation. This work was supported by a grant from the American Cancer Society (RSG-08-199-01) and a grant from the Department of Defense (W81XWH-07-1-0191).

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 4544. doi:10.1158/1538-7445.AM2011-4544
Abstract 4548: The role of GPR30/G-protein coupled estrogen receptor (GPER) in lung cancer development
Authors: Jala Venkatakrishna R. , Bodduluri Haribabu , Radde Brandie , Klinge Carolyn M.
Published: June 2012

Lung cancer is currently the leading cause of cancer deaths both in men and women. Estrogens, including 17β-estradiol (E2), are known to promote various cancers including breast, endometrial, and ovarian cancers. Women are at higher risk for lung adenocarcinoma than men, implying a potential role for estrogens in lung cancer. E2 mediates its genomic effects through two well-characterized nuclear receptors, estrogen receptor α (ERα) and estrogen receptor β (ERβ), both of which are expressed in normal lung and lung adenocarcinomas. In addition to genomic estrogen action, i.e., transcriptional regulation of gene expression, estrogens activate rapid, non-genomic responses such as intracellular calcium release, cAMP production, MAPK and PI3K/AKT phosphorylation, and up regulation of c-fos transcription. These observations prompted a search for new estrogen receptors and culminated in the discovery of GPR30 (GPER) as a bona fide estrogen receptor that mediates some of the membrane actions of E2. GPR30 is a seven transmembrane G-protein coupled receptor (GPCR) unrelated to nuclear ERα and ERβ. Although GPR30 is expressed in healthy lung, its expression in lung tumors/lung cancer cell lines as well as its functional activities has not been investigated. In the current study, we investigated the expression of GPR30 in human and murine lung cancer cell lines and tumor tissues both at the transcript and protein levels. Our analyses demonstrated for the first time that GPR30 expression is significantly increased (2 to140 fold) in lung cancer cells lines (A549, H1435, H1395, H1944, H1792, H1793, H2073, H23, H1299, LLC) compared to immortalized normal human bronchioepithelial cells (HBEC3-ET, HBEC2-E, HBEC2-KT). The expression of GPR30 in lung tissue microarrays (LC242, LC1005 from USBiomax) containing 87 cases of lung cancer tissues along with normal and cancer adjacent tissues were analyzed by immunohistochemnistry (IHC). IHC scores confirm that GPR30 is significantly overexpressed in more than 80% of lung adenocarcinomas (p<0.0001), 75% of large cell carcinoma (p<0.0001) and 60% in squamous cell carcinoma (SCC) (p<0.0001). These observations suggest that E2, as well as other GPER ligands, signaling through GPR30 might play a critical role in lung carcinogenesis independent of the classical ERα and ERβ. Given the cross-talk between GPR30, ERα and epidermal growth factor receptor (EGFR) reported in other cell types, we suggest that blocking the signaling activities of GPR30, ERα, and EGFR may synergize to provide a better therapeutic option for treating 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 4548. doi:10.1158/1538-7445.AM2011-4548
Abstract 4549: Expression and localization of progesterone receptor membrane component 1 and 2 in normal and malignant endometrial cells
Authors: Kavandi Leyla , Ivanova Vessela S. , Nguyen Huyen , Syed Viqar
Published: June 2012

Recently, two progesterone receptor membrane components (PGRMC) have been identified. PGRMC-1 protein has been shown to be overexpressed in breast, colon, and thyroid cancers, whereas far less is known about PGRMC2. The purpose of this study was to assess the expression, localization and hormonal regulation of PGRMC-1 and PGRMC-2 in normal and malignant endometrial tissues and cell lines. Immunohistochemical analysis showed a high expression of PGRMC-1 in normal tissues and a stage dependent decrease was observed in endometrial cancer tissues. A progressive decrease of PGRMC-2 expression was evident in endometrial cancer tissues but was not as marked as in PGRMC-1. Dual immunofluorescent confocal microscopy demonstrated colocalization of PGRMC-1 and PGRMC-2 in the cytoplasm and nucleus of endometrial cancer (Ishikawa and ACI-126) cells. Of significance, in normal epithelial endometrial (NEE) cells PGRMC-2 was predominantly localized in the membrane, whereas PGRMC-1 showed cytoplasmic and nuclear expression. Treatment of cancer cells with progesterone (P4) translocated both PGRMCs to the nucleus, while in normal cells PGRMC-1, but not PGRMC2 was translocated to the nucleus of cells. The results suggest that expression of PGRMCs is regulated by P4 and the dynamic pattern of PGRMC1 and PGRMC2 expression in normal and malignant cells implicate their role in tumorigenesis.

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 4549. doi:10.1158/1538-7445.AM2011-4549
Abstract 4556: AR intragenic rearrangement and altered androgen receptor mRNA splicing in castration-resistant prostate cancer
Authors: Li Yingming , Alsagabi Majid , Tewfik Ahmed , Dehm Scott M.
Published: June 2012

Androgen depletion for advanced prostate cancer (PCa) targets activity of the androgen receptor (AR), a steroid receptor transcription factor required for PCa growth. The emergence of lethal castration-resistant PCa (CRPCa) is marked by aberrant re-activation of the AR despite ongoing androgen depletion. Recently, alternative splicing has been described as a mechanism giving rise to COOH-terminally truncated, constitutively active AR isoforms that can support the CRPCa phenotype. However, the pathologic origin of these truncated AR isoforms has not been described. The goal of this study was to investigate alterations in AR expression arising in a cell-based model of PCa progression driven by truncated AR isoform activity. We demonstrate that stable, high-level expression of truncated AR isoforms in 22Rv1 CRPCa cells coincides with intragenic rearrangement of a ∼35kb AR genomic segment, which contains several alternative AR exons. Analysis of metastatic CRPCa tissues indicated that related AR copy number alterations are frequent and often occur in conjunction with high-level AR amplification. Nucleotide-level resolution of the break fusion junction in 22Rv1 cells revealed a DNA repair signature consistent with a microhomology-mediated, replication-based mechanism of origin. Together, these data provide the first report of AR intragenic rearrangements in CRPCa and a link with pathologic expression of truncated AR isoforms in a cell-based model of PCa progression.

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 4556. doi:10.1158/1538-7445.AM2011-4556
Abstract 4558: Synergistic effect of alcohol and estradiol in breast cancer
Authors: Singh Ajeet , Shanmugam Arulkumaran , Rajoria Shilpi , George Andrea , Suriano Robert
Published: June 2012

Breast cancer is the most common malignancy and the second leading cause of death among women in the United States. In addition to the various risks associated with breast cancer development, an interesting epidemiological observation exists, which is an increase in breast cancer incidence with increased alcohol consumption. Post-menopausal women on estrogen replacement therapy are at an even greater risk suggesting a synergistic interplay between estrogen and alcohol. Since the risk of alcohol for breast cancer can be partly attributed to circulating estrogens, the alcohol-estrogen axis, currently understudied at the biological level, is a viable breast cancer etiological agent. The precise cellular and biochemical mechanism for the role of the estrogen- alcohol axis in breast cancer progression is poorly understood. To investigate this, an in-vitro study was performed using 4T1 breast cancer cell line. The breast cancer cells were treated with alcohol (0.5%), estradiol (E2, 10-8 M) and with combination of alcohol and E2. Alcohol and E2 treatment modulates activation of cell surface receptors, specifically the epidermal growth factor receptor 2 (Erb2), which subsequently affects signaling through downstream pathways, such as Akt and mTOR. Akt/mTOR pathways are related to tumor development, and are target for any therapeutic agent. Alcohol, E2 and the combination treatments elicited a significant stimulation of estrogen receptor (ERα), Erb2, Akt and mTOR in 4T1 breast cancer cells. Accordingly, our data suggest that ERα, Erb2, Akt and mTOR may serve as key regulators that are involved in alcohol induced breast cancer progression. Thus the present study reveals the key pathways for alcohol-mediated promotion of cancer that could be targeted for therapy or prevention of alcohol-related cancers.

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 4558. doi:10.1158/1538-7445.AM2011-4558
Abstract 4574: Towards a new targeted therapy for ovarian cancer : Development of an anti-human müllerian inhibiting substance type II receptor humanized antibody
Authors: Jacquet Alexandra , Kersual Nathalie , Garambois Véronique , Colombo Pierre-Emmanuel , Goncalvez Rui-Bras , Theillet Charles , Gaucher Christine , Fournier Nathalie , De Romeuf Christophe , Prost Jean-François , Urbain Rémi , Pèlegrin André , Teulon-Navarro Isabelle
Published: June 2012

Asymptomatic in early stages, ovarian cancer is a “silent killer” corresponding to the 5th cause of female deaths in US. In 2010 it is estimated that 21,880 women in US will be diagnosed with ovarian cancer. Due to the limitations of the current therapeutic approaches, there is a strong need for novel, more efficient, therapies. We describe here a humanized monoclonal antibody 3C23K targeting the human Müllerian Inhibiting Substance type II Receptor (MISRII), expressed on most ovarian cancer subtypes, including epithelial ovarian cancer (EOC) representing more than 90% of ovarian cancers.

Starting from murine monoclonal antibody 12G4, 3C23K was obtained following chimerization, humanization by CDR grafting and affinity maturation. Moreover, 3C23K displays a particular glycosylation profile known to favor effector recruitment in vitro and in vivo (EMABling®). Assessed on MISRII transfected cells (cov434-MISRII), 3C23K was characterized by an affinity constant to the antigen increased by 3 fold as compared to murine 12G4. In order to evaluate 3C23K efficacy in vitro and in vivo, we have established several MISRII expressing cell lines derived from patient primary EOC tumors. Functional characterization of 3C23K has been carried out in vitro, including antibody-dependent cell-mediated cytotoxicity (ADCC), complement dependent cytotoxicity, apoptosis and intracellular signaling. In particular, 3C23K was found to display a higher ADCC activity on MISRII expressing cell lines as compared to the same sequence expressed in CHO cells. In vivo, 3C23K exhibited a significant effect on tumor growth against several ovarian tumor xenografted models derived from patient primary EOC tumors.

Altogether these data strongly suggest that humanized monoclonal antibody 3C23K may represent a promising candidate for ovarian cancer immunotherapy.

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 4574. doi:10.1158/1538-7445.AM2011-4574
Abstract 4584: Pre-clinical studies of a novel antibody to treat pancreatic and colorectal cancers
Authors: Bristol Andrew , Kantor Judith , Luka Janos , Stafford Joe , Gupta Rishab , Arlen Philip
Published: June 2012

Introduction:

NPC-1C is a chimeric monoclonal antibody being developed as a novel biological treatment for pancreatic and colorectal cancers. NPC-1C appears to recognize a variant form of MUC5AC expressed specifically by human pancreatic and colorectal tumor tissues and cell lines. Here we show pre-clinical studies in preparation for testing this therapeutic for a Phase I clinical trial.

Methods:

The NPC-1C antibody was selected from a panel of hybridomas generated from mice immunized with semi-purified membrane-associated proteins derived from biologically screened, pooled human allogeneic colon cancer tissues. In vitro assays and in vivo studies were performed to characterize the GMP-grade antibody.

Results:

Here we show that NPC-1C reacts with colorectal and pancreatic tumor tissues, but does not cross-react with normal human tissues, except for occasional, weak binding to certain GI tract tissues, which may indicate a pre-malignant state. The NPC-1C antibody exhibits cell-specific binding and ADCC activity against human colorectal and pancreatic tumor cells, but not against control tumor cell lines. In vivo, the anti-tumor efficacy of NPC-1C was tested using pre-established subcutaneous human tumor xenograft models. The data showed significant, and reproducible, anti-tumor action, including some complete tumor regressions. The pre-clinical toxicity profile of NPC-1C in normal BALB/c mice demonstrated little, if any, toxicity following single or multiple intravenous injections. The bio-distribution of radiolabeled NPC-1C in mice with pre-established human tumors revealed specific accumulation of NPC-1C at the tumor site, with little or no binding or accumulation in several major organ systems. Finally, the cytokine and antibody responses to NPC-1C were studied in the pre-clinical mouse model. Although anti-NPC-1C antibodies were detected (as expected) in a time-dependent fashion, there were no changes detect in Type I and Type II cytokines either 3 days or 14 days after intravenous administration.

Conclusions:

The pre-clinical development of NPC-1C indicates that it is safe and efficacious, and suggests that it may have clinical activity in patients whose tumor expresses the variant MUC5AC epitope. The potential clinical application for this antibody was bolstered by showing approximately 50-70% of human pancreatic and colon tumor tissues stained positively with NPC-1C. The therapeutic antibody is now being tested in a Phase I clinical trial in patients with advanced pancreatic and colorectal 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 4584. doi:10.1158/1538-7445.AM2011-4584
Abstract 4586: Essential role of fibroblast growth factor receptor 2 (FGFR2) in tumorigenesis of human cancers with activated FGFR2 signaling demonstrated by functional blocking antibodies
Authors: Bai Ailin , Meetze Kristan , Vo Nhi Y. , Kollipara Sriram , Mazsa Elizabeth K. , Winston William M. , Weiler Solly , Poling Laura L. , Chen Ting , Haserlat Sara , Abbott Sandra , Tissire Hamid , DiPrima Michael , Ismail Nesreen S. , Jiang Jinwei , Lerner Lorena , Gyuris Jeno , Weng Zhigang
Published: June 2012

Aberrant activation of fibroblast growth factor receptor 2 (FGFR2) signaling, through overexpression of FGFR2 and/or its ligands, mutations, and receptor amplification have been found in a variety of human tumors. We generated monoclonal antibodies against the extracellular ligand binding domain of FGFR2 to address the role of FGFR2 in tumorigenesis and to explore the potential of FGFR2 as a novel therapeutic target. We identified a broad panel of human cancer cell lines with dysregulated FGFR2 signaling and examined the sensitivity of these human cell lines to monoclonal antibodies specifically targeting FGFR2. These FGFR2 antibodies potently suppressed ligand-induced phosphorylation of FGFR2 and downstream signaling, as well as cell proliferation in vitro. The administration of FGFR2 monoclonal antibodies in mice significantly inhibited the growth of human cancer xenografts harboring activated FGFR2 signaling. Our findings support that dysregulated FGFR2 signaling is one of the critical oncogenic pathways involved in the initiation and/or maintenance of tumors. Cancer patients with aberrantly activated/amplified FGFR2 signaling could potentially benefit from therapeutic intervention with FGFR2-targeting antibodies.

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 4586. doi:10.1158/1538-7445.AM2011-4586
Abstract 4589: Gamma-tocopherol and mixed tocopherols inhibit AOM-induced colon carcinogenesis that was promoted by moderate but not severe colon inflammation caused by dextran sodium sulfate
Authors: Jiang Qing , Jiang Ziying , Moreland Michelle
Published: June 2012

Our previous studies indicate that specific forms of vitamin E such as gamma-tocopherol (gT), the predominant form of vitamin E in US diets, have anti-inflammatory activities by inhibition of proinflammatory eicosanoids including prostaglandin E2 and leucotriene B4. These eicosanoids are known to promote carcinogenesis of different types of cancer including colon cancer. We therefore hypothesize that gT may be an effective anticancer agent against colon cancer. In male BALC mice, we examined potential effect of gT and mixed tocopherols at 1000mg/kg diet on AOM induced colon carcinogenesis which was promoted by 3-cycle DSS (dextrane sodium sulfate, 1.5%, 2.5% and 2%). The results show that two months after carcinogenesis was induced, all the AOM-DSS mice developed tumors located in the distal colon with ∼12 tumors per mouse. Supplementation of gT or gT-rich mixed tocopherols had no significant effects on tumor incidence or tumor size. In a subsequent study, potential effect of gT and gT rich mixed tocopherols were examined in the AOM induced colon cancer that was promoted by moderate colon inflammation caused by one-cycle 1.5% DSS. GT supplementation, although had no effects on total tumor incidence, significantly (P < 0.05) suppressed the incidence of large tumor (>2 mm2) by 60%. Mixed tocopherols showed strong tendency in attenuation of tumor development (50%, P = 0.06). Interestingly, gT but not mixed tocopherols significantly attenuated DSS-induced colon inflammation. These results indicate that gT appears to have anticancer activities via anti-inflammatory mechanisms.

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 4589. doi:10.1158/1538-7445.AM2011-4589
Abstract 459: Activation of macrophages by IL-4 and other cytokines: priming for protumoral functions
Authors: Wang Hao-Wei , Gocheva Vasilena , Joyce Johanna A.
Published: June 2012

While macrophages are a fundamental constituent of the host immune system, tumor-associated macrophages (TAMs) have been shown to fuel tumorigenesis, although there remain many critical open questions regarding how TAMs acquire their tumor-promoting functions and how they actually facilitate tumor growth and progression. Previously, we have shown that TAM-supplied cysteine cathepsin proteases play critical roles in several steps of carcinogenesis including cell proliferation, angiogenesis and invasion. We have also identified interleukin-4 (IL-4) as a key tumor-derived factor which induces high cathepsin activity in TAMs. Here we set out to investigate the mechanisms underlying the induction of cathepsin activity in TAMs by IL-4, and to identify other factors that act in concert with IL-4 to trigger this activity switch.

Using a cell-based model, we have demonstrated that IL-4 upregulates the transcription of several cathepsins in bone marrow-derived macrophages (BMDMs) through a STAT6-dependent mechanism. In addition, by using an activity-based probe for cathepsin proteases, we have also shown that IL-4 can induce the secretion of active cathepsins from BMDMs. Moreover, several other cytokines that are expressed in the tumor microenvironment can act redundantly or synergistically with IL-4 to induce cathepsin expression and secretion. In sum, our data indicate that complex cytokine signaling pathways in the tumor microenvironment are capable of shaping the tumor-promoting phenotypes of TAMs in part through the induction of cathepsin activity.

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 459. doi:10.1158/1538-7445.AM2011-459
Abstract 4610: NO-NSAIDs inhibit colon tumor cell growth by a cGMP-independent mechanism
Authors: Gurpinar Evrim , Sun Yanjie , Keeton Adam , Tinsley Heather , Gary Bernard , Butler Braeden L. , Binkowski Brock F. , Kopelovich Levy , Athar Mohammad , Piazza Gary A.
Published: June 2012

Nitric oxide-releasing NSAIDs (NO-NSAIDs) were originally developed as prodrugs to reduce the gastrointestinal toxicity of conventional NSAIDs and were found to have improved potency to inhibit tumor growth compared with the parent NSAID. Although different mechanisms have been proposed for their potent anticancer properties, the role of the NO-moiety has not been clearly defined. We have investigated whether the NO group contributes to the anticancer properties of NO-NSAIDs by inducing soluble guanylyl cyclase and elevating intracellular cGMP levels, effects that are associated with the activity of NO donors. We confirmed the increased potency of the NO-derivatives of sulindac, aspirin (o-, p- and m- isomers), exisulind and naproxen with respect to the parent compounds for inhibiting growth of HCT116, SW480 and COLO741 human colon tumor cells. The two derivatives with the lowest IC50 values, NO-sulindac (16.50 µM) and NO-ASA(o) (8 µM) were also tested for cGMP elevation using a novel cGMP biosensor assay in live cells. In brief, HEK293 cells were transfected with a biosensor construct containing cGMP binding domains fused to the modified firefly luciferase gene (Promega) which produces bioluminescence in the cGMP-bound or ‘activated’ state. Cells were treated with NO-Sulindac, NO-ASA(o) and known NO-donors, NOR-3 and SNP as positive controls. Chemiluminescence was measured over a period of 1h. A strong and sustained signal was obtained with the NO-donors, SNP and NOR-3 (50 µM), although no induction was observed with NO-NSAID treatment (50 µM). In addition, SW480 colon tumor cells were treated with 50 µM NO-Sulindac, NO-ASA(o) or NOR-3 and levels of phosphorylated vasoactivator stimulated phosphoproteins (p-VASP), an intracellular marker of cGMP signaling activity, were measured by Western Blotting. NOR-3 caused a time-dependent increase in p-VASP expression, whereas the NO-NSAIDs had no such effect. Since sulindac and certain derivatives have previously been reported to inhibit cGMP-phosphodiesterase (PDE) and inhibit tumor cell growth by a mechanism involving cGMP elevation, we also determined if NO-NSAIDS can inhibit cGMP PDE activity. NO-NSAIDs did not inhibit cGMP hydrolysis by either recombinant PDE5 or in lysates from colon tumor cells, although sulindac sulfide was an effective inhibitor as previously reported. These results suggest that mechanisms other than cGMP elevation explain the anticancer properties of NO-NSAIDs. Funding provided by NIH/NCI grants CA131378 and CA148817.

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 4610. doi:10.1158/1538-7445.AM2011-4610
Abstract 4614: The organic panic
Authors: Jensen Jacob , Garrett Andrew , O'Neill Kim , Robison Richard
Published: June 2012

In today's market place organic foods have become a very popular topic of discussion. Some studies have compared the different benefits of organic foods vs. conventional foods in disease prevention, including cancer. Although differences have been examined, no broad or concrete conclusions have been reached. Studies have shown that consumption of antioxidants can decrease the risk of oxidative damage, degenerative conditions, and cancer. In this study, antioxidant levels between organic blueberries and conventional blueberries were analyzed and compared in their skin, seed, and juice using the Oxygen Radical Absorbance Capacity assay (ORAC). Data indicate that, in each sample category, conventional samples showed higher antioxidant activities overall when compared to organic samples. 15 organic samples and 15 conventional samples were taken for measurement of antioxidant activity. All values are reported as Trolox Equivalents per 100 grams sample (TE/100g). Conventional blueberry skin revealed highest overall antioxidant activity (7258 TE/100g, s=1024), while organic blueberry seed revealed the lowest (494 TE/100g, s=160). Conventional skin (7258 TE/100g, s=1024) revealed higher values than organic skin (3891 TE/100g, s=288). Conventional seed (1308 TE/100g, s=597) revealed higher values than organic seed (494 TE/100g, s=160). Conventional juice (5077 TE/100g) revealed higher values than organic juice (2205 TE/100g, s=276). Student's t-test analysis revealed statistically significant differences between conventional and organic samples in all three groups (organic vs. conventional skin, p=1.3×10-5, organic vs. conventional seed, p=0.008; organic vs. conventional juice, p=0.022). Data from this study suggest that consumption of organic fruits may not provide higher antioxidant protection when compared to consumption of conventional samples; consumption on conventional blueberries may prove to be most beneficial. Further studies on other fruit samples may provide additional insight on the antioxidant benefits of organic and conventional fruits and vegetables.

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 4614. doi:10.1158/1538-7445.AM2011-4614
Abstract 4618: Oral administration of bitter melon extract prevents initiation of prostate cancer in TRAMP model
Authors: Ray Ratna B. , Ru Peng , Steele Robert , Oshima Kikyoko , Phillips Nancy , Nerurkar Pratibha
Published: June 2012

Prostate cancer remains the second leading cause of cancer deaths among American men. Earlier diagnosis increases survival rate in patients. However, treatments for advanced disease are limited to hormone ablation techniques and palliative care. Thus, new methods of treatment and prevention are necessary for inhibiting progression of the disease to a hormone refractory state. For centuries, Ayurveda has recommended the use of bitter melon (Momordica charantia) as a functional food to prevent and treat human health related issues. We have recently discovered an anti-proliferative effect of bitter melon extract (BME) in a number of cancer cell lines, including prostate, without affecting normal cell growth. Treatment of prostate cancer cells with bitter melon extract modulated Bax expression and induced poly(ADP-ribose) polymerase cleavage. TRAMP (transgenic adenocarcinoma of mouse prostate) male mice display prostatic intraepithelial neoplasia (PIN) at 10-12 weeks of age. We examined whether oral administration of BME as a dietary compound inhibits or delay the conversion of normal prostate to PIN in these mice. We have observed prevention of PIN in BME-fed mice as compared to untreated control. Further tissues analyses for mechanism of cancer prevention are in progress and the results will be discussed.

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 4618. doi:10.1158/1538-7445.AM2011-4618
Abstract 463: The role of cysteinyl leukotriene receptors and tumour associated macrophages in colon cancer progression
Authors: Zhang Yuan , Sime Wondossen , Sjölander Anita
Published: June 2012

The pro-inflammatory cysteinyl leukotrienes (CysLT) have been implicated to play a role in colon cancer. The biological effects of CysLTs are mainly mediated through two different G-protein coupled receptors CysLT1 and CysLT2. We have shown that LTD4 signaling via CysLT1 receptors is linked to tumourigenic processes in cancer cells1. On the other hand, signaling via CysLT2 receptors is involved in cancer cell differentiation2. Colon cancer patients with high CysLT1R and low CysLT2R expression demonstrate poor prognosis3. Tumor-associated macrophages (TAMs, M2 phenotype, CD68+) are not only a source of CysLTs in tumor tissue, but also promote cancer cell invasion. High macrophage content is associated with poor patient prognosis in many tumors. In breast carcinoma, EGF is secreted by activated macrophages, but not by normal or malignant epithelial cells4. CD47, expressed on tumor cells, is capable of interacting with its receptor Signal-regulatory protein α (SIRPα) on macrophages to negatively regulate phagocytosis.

Our aim is to investigate how TAMs affect tumor behavior, and to investigate the role of CysLT1 and CysLT2 receptor-switch, which might be caused by EGF, in cancer progression.

Our preliminary data shows that TAMs are the source of EGF in cancer patient tissue. EGF up-regulates CysLT1R and downregulates CysLT2R expression. Migration of colon cancer cell is enhanced by M2 compared to M1 macrophages in wound healing-assay. Boyden Chamber-assay shows that conditioned medium from colon cancer cells cultured enhances migration of M2 (150%) but not M1 macrophages. We are now investigating the influence of the CysLT1R activity on phagocytosis and proliferation.

These findings suggest TAMs secret various molecular factors, which potentially influence the overall process of tumor initiation. TAMs may also change the balance between CysLT1R and CysLT2R, and there by play an important role in colon cancer progression.

References

1 Öhd JF, Nielsen CK, Campbell J, Landberg G, Löfberg H, Sjölander A. Gastroenterology. 2003 124:57-70.

2 Magnusson C, Ehrnstrom R, Olsen J, Sjölander A. Cancer Res 2007 67:9190-8.

3 Magnusson C, Mezhybovska M, Lörinc E, Fernebro E, Nilbert M, Sjölander A. Eur J Cancer. 2010 46:826-35.

4 O'Sullivan C, Lewis CE, Harris AL, McGee JO. Lancet. 1993 342:148-9.

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 463. doi:10.1158/1538-7445.AM2011-463