bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 971: Identification of BCL6 targeted therapies for breast cancer through gene expression networks
Authors: Walker Sarah R. , Cerchietti Leandro C. , Nicolais Maria C. , Yuan Guo-Cheng , Melnick Ari , Frank David A.
Published: August 2012

Breast cancer remains a deadly disease for countless women, thus new treatment strategies must be developed. Since inappropriate activation of transcription factors is a common pathogenic event in breast cancer, targeting these proteins may be a tractable new strategy. In particular, we have found that the BCL6 transcriptional modulator is expressed in 11 out of 12 breast cancer cell lines. In addition, BCL6 has been reported to be expressed in the majority of high-grade ductal carcinomas. Importantly, inhibiting BCL6 expression by RNA interference reduced cell survival. We hypothesized that BCL6 target gene expression profiles could be used to identify compounds with BCL6 inhibitory activity. To generate a breast cancer specific BCL6 gene signature, we employed the combination of gene expression microarrays and BCL6 binding sites identified by ChIP-seq in breast cancer cells. These BCL6 target gene profiles were then used to interrogate the Connectivity Map, a compilation of gene expression signatures reflecting the effects of more than 1300 compounds. This allowed us to identify compounds whose gene expression signature was the inverse of that mediated by BCL6, and might thereby function as BCL6 inhibitors. We screened six of these compounds for BCL6 inhibitory activity using a BCL6-specific reporter which identified disulfiram, celastrol, and harmol as inhibitors of the transcriptional repressor effects of BCL6. Importantly, treating breast cancer cells with these compounds reduced the viability of these cells. Moreover, combining these compounds with cytotoxic agents used in breast cancer therapy enhanced cell killing. In addition, combining these agents with a peptidomimetic of BCL6 also enhanced cell killing. Taken together, these studies show that BCL6 is a key therapeutic target in breast cancer, and that gene signature analysis can be used to identify novel inhibitors of this protein that have activity in breast cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 971. doi:1538-7445.AM2012-971
Abstract 974: New target discovery for oncology utilizing phenotypic selection and primary NSCLC patient tumors
Authors: Holoweckyj Nicholas M. , Sandercock Alan , Guillard Sandrine , Rust Steven , Hay Carl , Brand Erin , Meekin John , Huang Qihui , Sachsenmeier Kris , Hollingsworth Robert E. , Minter Ralph , Bowden Emma
Published: August 2012

Lung cancer is the most common type of cancer, with approximately 222,000 new cases expected each year in the United States. Approximately 72% of the individuals diagnosed with lung cancer will fall victim to the disease. Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, but current treatments will not cure the disease for most patients. In an effort to identify novel therapeutics to address this unmet need, a phenotypic screening campaign was initiated. This type of target identification approach allows the discovery of novel drug targets by selection of antibodies based on their ability to elicit a specific desired phenotype. Once antibodies with the desired function are isolated, the targets to which the “hit” antibodies bind can be identified using a variety of approaches including IP-mass spec. Although phenotypic screens have been performed previously, the current effort has important advantages over those described previously. Specifically, this included the use of several unique screening assays run in parallel to allow the evaluation of multiple phenotypes simultaneously. Also unique was the use of primary material from NSCLC patients for both selection and functional screening. Specifically, we demonstrate the use of primary tumor cells in high throughput screening assays. We show the utility of incorporating novel screening assays including anoikis and spheroids with multiple endpoint readouts. Finally we provide data describing a series of “hit” antibodies isolated in the screen which had a variety of activities across the screening assays. These studies show the utility of function-first screening in the identification of unique potential therapeutic targets for oncology.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 974. doi:1538-7445.AM2012-974
Abstract 980: AMG 511, a potent and selective class I PI3K inhibitor, suppresses the growth of Kras mutant lung tumors in mice
Authors: Estrada Juan , Ungersma Sharon , Kaufman Stephen , Yerby Brittany , Zhang Nancy , Freeman Daniel , Hughes Paul , Silva Matthew , Coxon Angela
Published: August 2012

Background: Somatic activating mutations of KRAS are the most frequent genetic event in lung cancer, occurring in approximately 20% of NSCLC. KRAS activates two major oncogenic signaling pathways, the PI3K pathway and the MAPK pathway. Studies have suggested that blockade of both pathways is required to inhibit the growth of tumors driven by KRAS mutation. In this study, we investigated the effect of inhibiting solely the PI3K pathway on the growth of Kras G12D lung tumors in mice using AMG 511, a potent and selective class I PI3K inhibitor. To track tumor growth in this genetically engineered mouse model of lung carcinoma, we performed longitudinal monitoring of lung tumor burden during treatment using magnetic resonance imaging (MRI). Methods: Lox-stop-lox (LSL) Kras G12D mice were infected with Ad-Cre by intra-tracheal injection. Eight weeks after administration of virus, mice were randomized into two treatment groups and treated daily with 10 mg/kg AMG 511 or vehicle (N=11 per group). At 8, 11, and 14 weeks post-infection, mice were imaged using ultra-short echo time (UTE) MRI (N=6 vehicle, N=5 AMG 511). UTE MRI was performed with 30, 75, 150, 500, and 1000 αs echo times to visualize lung and tumor tissue. Lung borders were traced manually on MR images, and lung tumor volume was determined within the identified lung region using an intensity threshold to segment denser tumor tissue from normal lung tissue. At 14 weeks, lungs were harvested, weighed, and processed for histological analysis. Lung tissue area fraction was determined histomorphometrically from multiple step sections. UTE MRI images were correlated with histological sections from the same animal. Body weights were recorded. Results: Once daily treatment with AMG 511 at 10 mg/kg significantly inhibited the development of Kras G12D mutant lung tumors. Lung tumor volume, as assessed by UTE MRI, was reduced by 64% at 11 weeks (P<0.05) and 68% at 14 weeks (P<0.0005) post Ad-Cre infection, relative to vehicle-treated animals. The morphometric analysis of the same tissue showed a significant reduction in lung tissue area fraction that was consistent with the imaging results (up to 30% reduction, P<0.005). At the time of harvest, wet lung weights were also significantly reduced after treatment with AMG 511 (60% inhibition; P< 0.0001). AMG 511 had no effect on the bodyweights of the treated animals over the duration of the study. Conclusions: AMG 511 significantly inhibits the growth of Kras mutant lung tumors in mice, supporting the investigation of PI3K inhibition in patients with KRAS mutant tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 980. doi:1538-7445.AM2012-980
Abstract 983: Wnt pathway activation involves inhibition of β-catenin ubiquitination within the endogenous Axin1 complex
Authors: Li Vivian SW , Ng Ser Sue , Karthaus Wouter R. , Gerlach Jan P. , Mohammed Shabaz , Heck Albert , Maurice Madelon M. , Mahmoudi Tokameh , Clevers Hans
Published: August 2012

Degradation of cytosolic β-catenin by the APC/Axin1 Destruction Complex represents the key regulated step of the Wnt pathway. It is incompletely understood how the Axin1 complex exerts its Wnt-regulated function. We have now examined the compositional change of the endogenous Axin1 complex in HEK293T cells upon Wnt signaling. Our results demonstrate that not only phosphorylation, but also ubiquitination and proteasomal degradation of β-catenin occur within the Axin1 complex. In disagreement with current views, we find neither a disassembly of the complex, nor an inhibition of phosphorylation of Axin1-bound β-catenin upon Wnt signaling. Comparable observations are made in primary intestinal epithelium and in colorectal cancer cell lines carrying activating Wnt pathway mutations. Wnt signaling induces the loss of the dedicated E3 ligase α-TrCP from the complex, leading to complex saturation by accumulated phospho-β-catenin. Subsequently, newly synthesized β-catenin can accumulate in a free cytosolic form, travel to the nucleus and engage the TCF Wnt effector transcription factors. In contrast to current belief, the Axin complex remains compositionally intact in APC-mutant colorectal cancer. Rather, failure of β-catenin ubiquitination is the principle biochemical activating event in these malignant cells. Together we demonstrate a novel mechanism of the destruction complex for Wnt signal activation in both physiological and malignant states.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 983. doi:1538-7445.AM2012-983
Abstract CT-03: Aberrations in translational regulation are associated with poor prognosis in hormone receptor-positive breast cancer
Authors: Meric-Bernstam Funda , Chen Huiqin , Akcakanat Argun , Do Kim-Anh , Lluch Ana , Hennessy Bryan , Hortobagyi Gabriel , Mills Gordon , Gonzalez-Angulo Ana
Published: August 2012

Purpose: Translation initiation is activated in cancer through increase in eukaryotic initiation factor 4E (eIF4E), eIF4G, phosphorylated eIF4E-binding protein (p4E-BP1) and ribosomal protein S6 (pS6), and decreased programmed cell death protein 4 (pdcd4), a translational inhibitor. Further, translation elongation is deregulated though alterations in eukaryotic elongation factor 2 (eEF2) and eEF2 kinase (eEF2K). We sought to determine the association of these translational aberrations with clinical-pathologic factors and survival outcomes in hormone receptor-positive breast cancer. Methods: Primary tumors were collected from 190 patients with stage I-III hormone receptor-positive breast cancer. Expression of eIF4E, eIF4G, 4E-BP1, p4E-BP1 T37/46, p4E-BP1 S65, p4E-BP1 T70, S6, pS6 S235/236, pS6 S240/244, pdcd4, eEF2 and eEF2K was assessed by reverse phase protein arrays.: Univariable and multivariable analyses for recurrence-free survival (RFS) and overall survival (OS) were performed. Results: High eEF2, S6, pS6 S240/244, p4E-BP1 T70, and low pdcd4 were significantly associated with node-positivity. Median follow-up for alive patients was 96 months. High p4E-BP1 T36/47, p4E-BP1 S65, p4E-BP1 T70 and 4E-BP1 were associated with worse RFS. High p4E-BP1 T70 and pS6 S235/236, and low pdcd4, were associated with worse OS. In multivariable analysis, in addition to positive nodes, p4E-BP1 S65 remained a significant predictor of RFS (HR=1.62, 95%CI=1.13-2.31; P=0.008). In addition to age, pS6 S235/236 (HR=1.73, 95%CI=1.03-2.90, P=0.039), eEF2K (HR=2.19, 95%CI=1.35-3.56, P=0.002) and pdcd4 (HR=0.42, 95%CI=0.25-0.70, P=0.001) were associated with OS. Conclusions: Increased pS6, p4E-BP1, eEF2K and decreased pdcd4 are associated with poor prognosis in hormone receptor-positive breast cancer; suggesting their role as prognostic markers and therapeutic targets.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr CT-03. doi:1538-7445.AM2012-CT-03
Abstract LB-101: Quantitative imaging of protein expression using multiplex quantum dot immunohistochemistry
Authors: Cooper Lee A.D. , Yacoub Rami , Gutman David A. , Wang Fusheng , Moreno Carlos S. , Brat Daniel J. , Bostick Roberd M. , Saltz Joel H.
Published: August 2012

Introduction: Immunohistochemistry (IHC) is an important tool for studying protein expression in the tumor microenvironment. Advances in imaging hardware now permit an entire slide to be digitized at high magnification so that software can analyze protein expression within individual cells across the entire tissue section. The chromaphores and organic fluorescent probes used in traditional IHC limit the utility of quantitative IHC, since only relatively few proteins can be measured simultaneously. A new class of fluorescent labels made of semiconductor nanocrystals, known as quantum dots (QD) has unique optical properties that have the potential to overcome limitations of traditional IHC techniques and expand the usefulness of quantitative image analysis approaches. The narrowband emission spectra of these novel probes enable them to be highly multiplexed without significant spectral overlap, providing independent measurements of protein expression with minimal crosstalk. Methods: We have developed a collection of software algorithms around the QD-IHC protocol to analyze protein expression, co-expression, and subcellular localization in whole-slide QD-IHC images. This system segments the digitized tissue into individual cells, their subcellular compartments and multicellular structures to generate comprehensive digital descriptions. Features are calculated for each cell to represent the morphology, protein expression, co-expression, and subcellular localization. Each cell is mapped to their closest multicellular structure, enabling protein expression features to be analyzed as a function of distance to vessels, necrosis, etc. We evaluated the use of QD-IHC for analysis of formalin-fixed, paraffin-embedded glioblastoma tissues against known pathways using streptavidin-biotin detection and applied our software system to analyze expression and co-expression patterns. Features of protein expression were calculated for individual cells along with distance-to-vessel measurements. Results: A five-plex staining was achieved and sections were stained and digitized on a whole-slide scanner (Pannoramic from 3D Histech). The digitized tissues were analyzed using our software system to generate measurements of protein expression in millions of cells. These measurements were used to generate visualizations, including analyses of the variations of expression with respect to distance-to-nearest-vessel. We are continuing to enhance our software capabilities to include statistical tests and updated imaging and analysis capabilities will be presented.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-101. doi:1538-7445.AM2012-LB-101
Abstract LB-115: NAC1 is an actin binding protein essential for the cytokinesis of cancer cells and plays a role in the patterning of murine vertebral axis
Authors: Yap Kai Lee , Fraley Stephanie I. , Shah Polina Sysa , Wang Fengying , Thiaville Michelle M. , Jinawath Natini , Nakayama Kentaro , Wang Jianlong , Brayton Cory , Bolon Brad , Gabrielson Kathleen , Wirtz Denis , Wang Tian-Li , Shih Ie-Ming
Published: August 2012

Nucleus accumbens-associated protein 1 (NAC1) is a member of the BTB (Bric-a-Brac Tramtrack Broad complex) family of proteins. Recent studies have demonstrated NAC1 expression is essential for sustaining cancer cell proliferation and migration, but its molecular mechanisms remain elusive. In this report, we show that NAC1 is an actin monomer binding protein with a Kd of 0.78 μM, and the BTB domain is the actin-binding domain. Disrupting NAC1 protein complex function using a dominant-negative construct or RNA-interference resulted in reduced traction and incomplete abscission during late stage cytokinesis leading to multi-nucleation of cancer cells. We examined the phenotype of Nac1 knockout mice, and discovered the loss in expression of the Nac1 protein led to a patterning defect of the vertebral skeletal axis. Nac1-null mice were correlated with morphological transformation of the sixth lumbar vertebra into a sacral identity; a decreased total number of pre-sacral vertebrae elements from 26 in wild type mice to 25. Taken together, we explored the role of NAC1 as an actin binding protein essential for the cytokinesis of cancer cells, and its effects on patterning of the murine vertebral axis. These findings advance our knowledge of this physiologically-relevant protein in the field of mammalian development and cancer biology.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-115. doi:1538-7445.AM2012-LB-115
Abstract LB-160: CYP4F isoform expression and 20-HETE synthesis in prostate cancer cells are regulated by androgen and contribute to growth
Authors: Wu Cheng-Chia , Liu Yunmeng , Chen Jonathan , Gotlinger Katherine H. , Ramu Errabelli , Falck John R. , Schwartzman Michal L.
Published: August 2012

20-hydroxyeicosatetraenoic acid (20-HETE), a CYP450-derived arachidonic acid metabolite in the microcirculation, contributes to vascular tone and stimulates vascular and epithelial cell proliferation, angiogenesis and inflammation, all of which play a role in cancer progression. Our laboratory identified 20-HETE as the mediator of androgen-induced hypertension. Given that androgen contributes to the pathogenesis of prostate cancer, we examined the presence and function of 20-HETE in human prostate cancer cells. Androgen-responsive prostate cancer cells, LNCaP, produced 2-fold more 20-HETE compared to androgen-nonresponsive C4-2 cells (565±139 pg/mg protein vs 223±50 pg/mg protein). Both C4-2 and LNCaP produced greater amount of 20-HETE compared with U87 glioma, MCF-7 breast cancer and ML-1 thyroid cancer cells. 20-HETE levels in prostate primary stromal cells and epithelial RWPE-1 cells were barely detected (16±26 and 23±40 pg/mg protein respectively). Treatment of LNCaP with 5 alpha-dihydrotestosterone (DHT) stimulated 20-HETE production by 65% when compared to vehicle control. DHT treatment did not alter 20-HETE levels in C4-2. Treatment of C4-2 and LNCaP with HET0016, an inhibitor of 20-HETE synthesis, selectively decreased endogenous 20-HETE production while inhibiting cell growth in a dose-dependent manner. Further addition of exogenous 20-HETE stimulated growth. CYP4F2, CYP4F3 and CYP4F8 mRNA levels were several fold higher in LNCaP compared with C4-2, while levels of CYP4A11 and CYP4A22 mRNA were unchanged. In LNCaP, DHT increased CYP4F isoform expression without altering the CYP4A expression; flutamide abrogated DHT-induced expression of CYP4F2 and CYP4F3 but did not affect expression of CYP4F8. Importantly, flutamide inhibited DHT-stimulated 20-HETE production. These results suggest that 20-HETE has an important role in cancer cell proliferation and CYP4F2/3 might be the source of androgen-driven 20-HETE synthesis via androgen receptor dependent pathway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-160. doi:1538-7445.AM2012-LB-160
Abstract LB-178: A novel chemopreventive molecular mechanism of selenium: p53-mediated DNA repair
Authors: Seo Young Rok
Published: August 2012

Selenium is an essential trace element which has been considered as chemopreventive agent against cancer, due to its antioxidant activity. Among several selenium compounds, selenomethionine (SeMet) has significant protective effect toward various genotoxic stresses via stimulating DNA repair process. However, its mechanism is still not well elucidated. In this study, we examined the mechanism of SeMet in terms of p53-mediated base excision repair (BER). Our data showed that the amount of DNA damage was rapidly decreased in the presence of SeMet when methyl methanesulfonate (MMS), a BER-inducing agent, was treated in the cells. In addition, the removal of apurinic/apyrimidinic sites was significantly enhanced in p53 wild type cells in response to SeMet. Furthermore, we observed the Gadd45a, known to involve BER as one of the p53 downstream genes, was accumulated by SeMet in p53 wild-type RKO cells. Indeed the interaction of BER-mediated repair proteins including PCNA (proliferating cell nucleus antigen) and APE/Ref-1 with Gadd45a was notably decreased by SeMet in p53 siRNA-treated cells. In in vivo study, the frequency and size of polyp in AOM/DSS model as an animal model for colitis-related carcinogenesis was decreased in response to SeMet. Moreover, proteins related with DNA repair including Trx (thioredoxin), p53 and Gadd45a were increased in SeMet treated AOM/DSS model. Those results suggested that BER activity might be dependent on wild-type p53 under the modulation of protein complexes with Gadd45a and repair protein including PCNA and APE/Ref-1 as a distinct chemopreventive mechanism of SeMet. Our study might provide an important evidence to develop the chemopreventive strategies against various oxidative stresses.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-178. doi:1538-7445.AM2012-LB-178
Abstract LB-19: Interaction of GPR56 with TG2 regulates melanoma progression
Authors: Yang Liquan , Friedland Scott , Mohanty Sonali , Xu Lei
Published: August 2012

GPR56 is a member of a newly described adhesion G protein-coupled receptor family. We previously reported that the expression of GPR56 significantly inhibited tumor progression of human melanoma cells, and its N-terminus binds to tissue transglutaminase (TG2), a major crosslinking enzyme in ECM. To investigate the contribution of TG2 to GPR56-regulated melanoma progression, we analyzed the tumor growth of the melanoma cell line, MC-1, in the presence or absence of TG2. Our data showed that ectopic GPR56 expression abolished the influence of TG2 on tumor growth, whereas knocking down GPR56 in tumor cells dramatically enhanced TG2's tumor promoting effect. Consistently, interrupting the interaction of constitutive GPR56 with TG2 by overexpression of a free GPR56-N fragment significantly increased tumor growth. However, removing TG2 almost completely blocked tumor formation from GPR56-knocking down cells but not from control or GPR56-overexpressing cells. Collectively, our data revealed a model in which GPR56 plays dual roles during melanoma progression: it antagonizes the tumor-promoting effects of TG2 but positively regulates the tumor initiation/maintenance of melanomas. To investigate further how GPR56 might antagonize the function of TG2 in melanoma progression, we examined the expression/deposition of ECM components in cells and in tumor. Our data demonstrated that GPR56 regulates the distribution of TG2 and its partners in tumor ECM in vivo. Taken together, we present evidence here that a novel adhesion receptor, GPR56, regulates melanoma progression by modulating TG2 in the tumor microenvironment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-19. doi:1538-7445.AM2012-LB-19
Abstract LB-194: The Wnt inhibitor VS-507 reduces cancer stem cell (CSC) function in vitro and tumorigenicity in mice
Authors: Pachter Jonathan A. , Ring Jennifer , Neill Alissa , Vidal Christian , Sullivan Brian T. , Sprott Kevin T. , Padval Mahesh , Xu Qunli
Published: August 2012

VS-507 was previously identified as a selective inhibitor of cancer stem cells (Gupta et al., Cell, 2009) using a high throughput screen that capitalized on the cancer stem cell (CSC) phenotype of cells pushed through EMT (epithelial-mesenchymal transition). We have now characterized the mechanism, CSC selectivity and anti-tumor activity of VS-507. In Wnt3A-stimulated MDA-MB-231 breast cancer cells, VS-507 was found to preferentially inhibit β-catenin signaling in a dose-dependent manner as indicated by a TOP-Flash reporter assay. Inhibition of β-catenin signaling in VS-507-treated cells correlated with decreased protein expression of LRP6, the common co-receptor of the Wnt signaling pathway. Since human mammary cells driven through EMT by stable overexpression of the transcription factor Twist have been shown to demonstrate the hallmarks of CSCs, we used HMLE-Twist cells to assess selectivity of VS-507 for CSC inhibition. In proliferation assays, VS-507 showed 10-fold greater potency against CSC-like mesenchymal HMLE-Twist cells as compared to non-CSC-like epithelial control HMLE cells. In addition, VS-507 induced dose-dependent inhibition of tumorsphere formation by MDA-MB-231 cells, further indicating inhibition of the CSC phenotype. The preferential effects of VS-507 on mesenchymal breast cancer cell lines relative to epithelial breast cancer cell lines was further probed among a panel of 13 adherent human breast cancer cell lines. In general, triple negative mesenchymal breast cancer cell lines such as MDA-MB-436 or HCC1395 were more potently inhibited by VS-507 than were epithelial breast cancer cell lines such as MCF7 or HCC1937. Finally, efficacy of VS-507 was characterized upon systemic administration of the compound to mice. Inhibition of both primary tumor growth and experimental metastasis were observed in triple negative breast cancer models. These observations suggest that VS-507 is a potent anti-tumor agent that attenuates Wnt/β-catenin signaling, cancer stem cell self-renewal, tumor growth and metastasis. These results support clinical development of VS-507 for the treatment of triple negative breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-194. doi:1538-7445.AM2012-LB-194
Abstract LB-323: Self-reported sleep duration and subsequent risk of colorectal cancer in two large cohorts of women and men
Authors: Zhang Xuehong , Giovannucci Edward , Wu Kana , Gao Xiang , Hu Frank , Ogino Shuji , Schernhammer Eva , Fuchs Charles , Pollak Michael , Willett Walter , Ma Jing
Published: August 2012

Background: Short sleep duration was associated with an increased risk of colorectal adenomas in a recent report. To date, no data are available on the relationship between sleep duration and colorectal cancer risk. Method: We prospectively followed 76,368 women aged 40 to 73 years in the Nurses’ Health Study and 28,676 men aged 41 to 79 years in the Health Professionals Follow-up Study who reported their habitual sleep duration in the mid-1980s. We used Cox proportional hazards regression models to estimate multivariable relative risks (MV RRs) and 95% confidence intervals (CIs) adjusting for known risk factors (dietary and non-dietary) for colorectal cancer. Results: A total of 1,925 incident colorectal cancer cases (1,264 in women and 661 in men) were documented during up to 22 years of follow-up. The median of sleep duration was 7 hours in both cohorts and was used as the reference group. In both age-adjusted and the multivariate models, long sleep duration (i.e., at least 9 hours of sleep) was significantly positively associated with risk of colorectal cancer in men (MV RR=1.49; 95%CI: 1.10, 2.03) but not in women (MV RR=1.10; 95%CI: 0.85, 1.43). However, for the same comparison (i.e., at least 9 hours vs. 7 hours of sleep), among overweight (body mass index at least 25 kg/m2) individuals, we found significant positive associations for both men (MV RR=2.66; 95%CI: 1.81, 3.90) and women (MV RR=1.42; 95%CI: 1.01, 1.99). Short sleep duration (i.e., 5 hours or less of sleep) was not associated with colorectal cancer risk in either men (MV RR=0.65; 95%CI: 0.33, 1.28) or women (MV RR=1.14; 95%CI: 0.88, 1.48). Results were essentially unchanged when we excluded cases occurred in the first 4 years of follow-up. In addition, the association was not significantly modified by physical activity, alcohol consumption, endoscopy screening, family history of colorectal cancer, menopausal status, or shift work (women only). Conclusion: These prospective data from two large cohorts suggest that overweight men and women with a sleep duration of 9 or longer hours had a significantly increased risk of developing colorectal cancer when compared to those with 7 hours of sleep, which cannot be explained by known risk factors or reverse causality. The potential mechanisms behind this association deserve further investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-323. doi:1538-7445.AM2012-LB-323
Abstract LB-333: A case-parent-triad approach in assessing risk of osteosarcoma associated with genetic variation in insulin-like growth factor 1/growth hormone axis genes: a Children's Oncology Group (COG) study
Authors: Musselman Jessica , Bergemann Tracy , Krailo Mark , Malkin David , Ross Julie , Savage Sharon , Nagarajan Rajaram , Sklar Charles , Spector Logan
Published: August 2012

Osteosarcoma (OS) is a rare malignant bone tumor with an overall incidence rate of 4.6 cases per million children aged 0-19 years in the United States. OS incidence peaks sharply in adolescence coinciding with the pubertal growth spurt. While the etiology of OS is largely unknown, its distinctive age-incidence pattern suggests that growth and development is crucial in the genesis of OS. Prior studies have suggested that variants in genes in the insulin-like growth factor 1 (IGF1)/growth hormone (GH) axis pathway are associated with OS. We assessed this hypothesis by examining 307 single nucleotide polymorphisms (SNPs) in 12 genes from this pathway (GHRH, GH1, GHR, GHRHR, IGF1, IGF1R, IGF2, IGF2R, IGFBP1, IGFBP3, IGFBP6, AND IGFALS) in a case-parent-triad study of cases and their biological parents. The sample included 229 complete triads and 56 dyads diagnosed during 2008-2011 at Children's Oncology Group institutions. Buccal cell samples were collected via the Oragene kit (DNA Genotek, Ottawa, Ontario) and returned by mail; genotyping was conducted by Sequenom iPLEX Gold method. We used log-linear models to estimate relative risks (RR) and 95% confidence intervals (CI) associated with transmitting one or two copies of the variant compared to no copies. After Bonferroni correction, 2 SNPs in IGFBP1 (rs10231774: RR = 1.44 and 0.07 for 1 and 2 vs. 0 copies, respectively; p < 0.001) and IGFALS (rs2575352: RR = 2.82 and 0.22 for 1 and 2 vs. 0 copies, respectively; p < 0.001), both in the upstream coding regions of IGF pathway genes, were significantly associated with OS incidence. These results confirm previous findings that variation in the IGF1/GH axis influence OS risk and further support the axis’ biologically and epidemiologically plausible role in OS development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-333. doi:1538-7445.AM2012-LB-333
Abstract LB-344: Emergence of carcinoma resistance to EGFR blockade via an integrin avb3/RalB/NFkB signaling axis
Authors: Seguin Laetitia J. , Mielgo Ainhoa , Huang Miller , Camargo Fernanda Camargo , Lesperance Jacqueline , Weis Sara M. , Desgrosellier Jay S. , Cheresh David A.
Published: August 2012

EGFR inhibitors have been used to treat several cancers including pancreatic, breast, lung and colorectal cancers. However, resistance to EGFR inhibitors has emerged as a significant clinical problem. KRAS activation in cancer has been associated with tumor cell resistance to EGFR inhibition. Here we identify integrin αvβ3 as a marker for tumors that are resistant to EGFR blockade. In addition, we find that tumor cells initially lacking or expressing low levels of integrin αvβ3 specifically upregulate this integrin upon treatment with EGFR inhibitors. Surprisingly, αvβ3, even in the unligated state, interacts with and promotes a specific KRAS ependent function leading to the EGFR independent growth of various tumors. Specifically, αvβ3 promotes KRAS dependent activation of RalB and its downstream effectors TBK1/NFkB and Src leading to tumor growth in the presence of EGFR inhibitors. Accordingly, knockdown of RalB sensitizes αvβ3-expressing tumors to EGFR blockade while expression of an active RalB mutant promotes resistance of αvβ3 negative tumor cells to EGFR blockade. These findings reveal a new role for integrin αvβ3 in mediating tumor cell resistance to EGFR inhibition through activation of a specific KRAS dependent function. Our findings suggest a new way to circumvent EGFR resistance of a wide range of cancers by targeting the αvβ3/KRAS signaling pathway and its downstream effectors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-344. doi:1538-7445.AM2012-LB-344
Abstract LB-346: EGF receptor, Jaks and Stat3 crosstalk promote enhanced colony-forming, motility, migration, and invasive phenotype of cisplatin-resistant ovarian cancer cells
Authors: Yue Peibin , Zhang Xiaolei , Paladino David , Sengupta Bhaswati , Ahmad Sarfraz , Holloway Robert W. , Ingersoll Susan B. , Turkson James
Published: August 2012

Majority of the ovarian cancer patients who initially respond to cisplatin therapy develop recurrent and resistant disease that is mechanistically not well understood. To define the biological presentations and the molecular phenotype of cisplatin resistant ovarian cancer, we subjected the sensitive A2780S ovarian cancer line to multiple rounds of cisplatin treatments, followed by recovery and derived the lines, A2780S/CP1 (S/CP1), A2780S/CP3 (S/CP3), and A2780S/CP5 (S/CP5), which are resistant to 1, 3, and 5 μM cisplatin, respectively. In vitro studies show the three resistant lines have increased colony-forming ability and altered morphology consistent with enhanced motility, migration, and invasiveness. The malignant phenotype progresses with increasing resistance and is associated with hyperactive epidermal growth factor receptor (EGFR)/extracellular signal-regulated kinase 1/2 and Janus kinases (Jaks), and aberrant Signal Transducer and Activator of Transcription (Stat) 3 activation. Elevated expression of survivin and vascular endothelial growth factor (VEGF), and enhanced matrix metalloproteinase activities are evident in the resistant cells, together with increased vimentin and snail expression, and E-cadherin downregulation, indicative of epithelial-mesenchymal transition (EMT). The inhibition of EGFR or Stat3 activity in the resistant cells repressed the enhanced colony-forming, motility, and migratory phenotype, downregulated survivin, VEGF and vimentin expression, and sensitized the resistant cells to cisplatin. In vivo studies using intra-peritoneal xenograft models in nude mice revealed the resistant lines have a high tumor incidence and formed small, cisplatin-resistant tumor nodules at several locations on the small-intestine and colon, compared to the sensitive A2780S line that exhibited low tumor incidence and formed exclusively ovarian tumors. Treatment with EGFR or Stat3 inhibitor sensitized the resistant tumor nodules to cisplatin. Studies together indicate hyperactive EGFR and Jak signaling predominantly through the induction of aberrantly-active Stat3 promote EMT during cisplatin resistance development. Collectively, these events serve as critical mediators of the invasive phenotype associated with cisplatin resistant ovarian cancer and hence, are targets for preventing the development of resistance and the recurrent disease during cisplatin therapy in ovarian cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-346. doi:1538-7445.AM2012-LB-346
Abstract LB-349: ZO1 gene represents a chemosensitivity gene in multiple myeloma
Authors: Yang Lin , Orlowski Robert , Zhang Xingding , Meng Huimin , An Gangli , Wang Hua
Published: August 2012

Chemotherapy agents are extremely important in the treatment of liquid malignancies, such as multiple myeloma (MM). Unfortunately, chemotherapy resistance in MM therapy is the most significant cause of treatment failure. The ability to predict, treat, or circumvent resistance is extremely likely to improve clinical outcomes. Thus, identification of novel genes that play a crucial role in MM progression and chemosensitivity is necessary to understand this disease better at the molecular level. Moreover, these genes and their products may serve as new therapeutic targets for MM, whose expression could improve patient outcomes or served as a predictor for chemotherapy outcome. To identify potential chemosensitivity genes, establishing a high-throughput method for validation of targets becomes urgently needed. Toward this purpose, we have successfully developed a high-throughput siRNA based functional target validation approach and identified a group of potential chemosensitivity genes. Our preliminary studies focusing on one of the candidate gene, ZO1 (zonula occludens 1), suggested that targeting ZO1 led to tumor cell resistant to several chemotherapy agents, including doxorubicin (Dox), cisplatin (Cis), methotrexate (MTX), and bortezomib. Further analysis with 264 bortezomib treated MM patients indicated that expression level of ZO1 correlated with patient response to bortezomib treatment. Two clones and pooled RPMI 8226 MM cell line, which were developed against bortezomib treatment in our lab, showed loss of ZO1 expression, suggesting a role of ZO1 may play in bortezomib resistance development. More importantly, ZO1 targeting in myeloma cells resulted in cell resistance to bortezomib treatment. Taken together, our studies reveal a novel chemosensitivity gene, which may lay the foundation for further clinical studies. Moreover, in the clinical arena, it may form a basis for algorithms to help predict chemosensitivity based on baseline gene expression profiles in the future, and may provide the strategies aimed at enhancing chemosensitivity by increasing expression of target genes of interest.[[Unsupported Character -  ]]

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-349. doi:1538-7445.AM2012-LB-349
Abstract LB-363: Intravesical delivery of lipid nanoparticle formulated p21(Waf1/Cip1) activating dsRNA induces tumor regression and enhances animal survival in a orthotopic bladder cancer model
Authors: Kang MooRim , Yang Glen , Charisse Klaus , Epstein-Barash Hila , Manoharan Muthiah , Li Long-Cheng
Published: August 2012

Small RNA molecules are a promising new class of drugs by offering expanded targets not druggable by conventional therapies with high target specificity and low toxicity. However, their clinical use is significantly hindered by the lack of vehicles that deliver the molecules efficiently to target tissues and cells. The bladder is an easily accessible hollow organ and is ideal for local delivery of drugs or molecules such as small RNA. RNA activation (RNAa) is a newly discovered mechanism of gene induction triggered by promoter targeted double-stranded RNA, also known as small activating RNA (saRNA). In this study, we investigate, in an orthotopic bladder cancer model, antitumor effects of a saRNA (dsP21) targeting the promoter of the p21WAF1/CIP1 (p21) gene, a key negative regulator of the cell cycle rarely mutated or deleted in bladder cancer. Introducing dsP21 into bladder cancer cells activated p21 expression with subsequent inhibition of cell proliferation, arrest of the cell cycle and induction of apoptosis accompanied by the activation of caspase 3 and PARP. Chemical modification (2′-Fluoro) and subsequent formulation of dsP21 in lipid nanoparticles (LNPs) retained its RNAa activity with minimal immunostimulatory effect and extended its stability in urine, and when delivered intravesically it could well diffuse into the bladder wall. Delivery of LNP-formulated dsP21 (LNP-dsP21) into mouse bladder with established human bladder cancer significantly inhibited tumor growth and extended animal survival with demonstrated p21 activation in vivo. Of particular significance, LNP-dsP21 treatment caused the regression or disappearance of established tumors in 30% of the treated mice. Our results provide proof-of-principle that targeted activation of p21 can be applied to the treatment of bladder cancer and LNP-formulated small RNA can be successfully delivered to the bladder by intravesical instillation. Further clinical development of RNAa-based intravesical therapy is warranted for the treatment of residual and recurring bladder cancer in humans. Acknowledgement: financial support from the AACR Henry Shepard Bladder Cancer Research Grants (09-60-30-LI).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-363. doi:1538-7445.AM2012-LB-363
Abstract LB-369: Coxsackievirus B3 is an immunostimulatory oncolytic virus active against lung adenocarcinoma
Authors: Miyamoto Shohei , Inoue Hiroyuki , Wang Beibei , Yasunari Keisuke , Nakamura Takafumi , Yamada Meiko , Urata Yasuo , Marumoto Tomotoshi , Takahashi Atsushi , Takayama Koichi , Nakanishi Yoichi , Shimizu Hiroyuki , Tani Kenzaburo
Published: August 2012

Although oncolytic virotherapy is a promising anticancer therapy, antitumor efficacies are hampered by low tumor selectivity. To identify a potent and selective oncolytic virus, we performed large-scale two-step screening of 28 enteroviral strains and found that coxsackievirus B3 (CVB3) possessed specific oncolytic activity against nine human non-small cell lung cancer (NSCLC) cell lines. CVB3-mediated cytotoxicity was positively correlated with the expression of viral receptors, CAR and DAF, on NSCLC cells, and attenuated by loss of CAR expression by siRNA transfection on NSCLC cells. In vitro assays revealed that CVB3 induced apoptosis and PI3K/Akt and MEK/ERK survival signaling pathways, leading to cytotoxicity and regulation of CVB3 replication. Intratumoral injections of CVB3 elicited remarkable regression of pre-established tumors in vivo. Furthermore, administration of CVB3 into xenografts on the right flank resulted in significantly durable regression of uninjected xenografts on the left flank, where replication-competent CVB3 was detected. All treatments with CVB3 were well-tolerated without treatment-related deaths. In addition, intratumoral CVB3 administration markedly recruited NK cells and granulocytes, both of which expressed cytolytic degranulation marker CD107a and contributed to the antitumor effects as demonstrated by depletion assays, macrophages, and mature dendritic cells (DCs) into tumor tissues. Furthermore, we found that CVB3 infection induced abundant calreticulin (CRT) exposure, known as a major checkpoint of immunogenic cell death, on the cell surface of NSCLC cells, as well as extranuclear high mobility group box 1 (HMGB1) translocation from the nuclei to the cytosol in NSCLC cells. Altogether, our findings suggest that CVB3 is a potent and well-tolerated oncolytic agent with immunostimulatory properties active against both localized and metastatic NSCLC and may yield a unique and more effective antitumor activity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-369. doi:1538-7445.AM2012-LB-369
Abstract LB-397: Deep sequencing of Xenografts and case-matched blood and primary tumors reveals a 20 folds enrichment of loss of heterozygosity versus somatic mutations suggesting LOH plays an ever important role in tumorigenesis
Authors: Xu Qiang , Wang Guan , Fang Douglas D. , Gao Yibo , Chen Yundi , Sun lele , Yan Xuelan , Li Ou , Yang Quanyu , Qian Maoxiang , Zhang Bin , Chen Zhaoli , Chan Chi-Chung , Sun Hongye , He Jie
Published: August 2012

The double hits theory suggests a major mechanism of tumorigenesis. However, compared to the somatic mutations, the loss of heterozygosity (LOH) was not frequently identified in many sequencing projects. Unlike the somatic mutations that were detected by the evidence of novel alleles in tumor tissue, the alleles involving in the LOH are present in normal tissues as well. Given the high level of tissue heterogeneity of primary tumors, including both tumorous cells and normal stroma cells, at whole tissue or million cells level LOH can only be detected as a quantitative change between tumor and normal samples, which are not easily distinguished from potential sequencing errors or other artifacts especially with low depth sequencing. By applying whole exome capture deep sequencing on case-matched primary tumor, blood and xenograft samples, we found that xenografts represent a much purer human tumor cell population than primary tumor tissues. These tumor cells growing in mice not only contain the majority of somatic mutations in the primary tumors (>95%), but also reveal a >20 folds enrichment of somatic LOH events, which were not categorized as LOH in primary tumors, versus somatic mutations. All these findings were detected after removing mouse sequence contaminations, which if included will induce about half of the total variations observed in the xenograft samples. We found that these LOH events affect both tumor suppressor genes and oncogenes. Given that driver mutations or other variations that are implicated in oncogenesis are most likely preserved in xenografted tumor cells in immunedeficient mice, we hypothesize that the bigger range of somatic LOH events that we observed in xenograft samples play a potential ever important role in tumorigenesis than what we thought previously. Our finding also sheds a new light on a novel approach for the discovery of potential drug targets by sequencing xenograft samples.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-397. doi:1538-7445.AM2012-LB-397