bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2633: Single nucleotide polymorphisms in one carbon metabolism genes are associated with methylation patterns and plasma metabolites in high risk smokers based on gender
Authors: Flores Kristina G. , Stidley Christine A. , Picchi Maria A. , Mackey Amanda J. , Stabler Sally P. , Byers Tim , Berwick Marianne , Belinsky Steven A. , Leng Shuguang
Published: August 2012

Lung cancer is the leading cause of cancer related deaths and most lung cancers are detected at a late stage. Gene promoter hypermethylation is now regarded as a promising biomarker to identify early risk and progression of lung cancer. The one carbon metabolism pathway is postulated to affect DNA methylation because it is necessary for the generation of S-adenosyl methionine or (SAM), the methyl donor for cellular DNA methylation reactions, through complex interactions with metabolites including folate, homocysteine, and methionine. This study investigated the association of single nucleotide polymorphisms (SNPs) in one carbon metabolism related genes with DNA promoter hypermethylation in sputum cell DNA from current and former smokers in the Lovelace Smokers Cohort (n=907). The association of SNPs with methylation was analyzed by logistic regression using gender specific high and low methylation cutoffs from a 12 gene methylation panel as the outcome. SNPs in the cystathionine beta-synthase (CBS) and 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) genes were found to be statistically associated with methylation in a gender specific fashion (CBS SNP, OR=4.9; CI: 1.98, 12.2, p=.0006 in males) and (MTRR SNP, OR= 0.57, CI: 0.42, 0.77, p=0.0003 in females). Plasma homocysteine levels and the ratio of homocysteine to cystathionine increased in male samples with heterozygous or homozygous minor alleles of the CBS SNP compared to male samples with homozygous common alleles (n=86). This study suggests that SNPs in the CBS and MTRR genes are associated with methylation patterns in smokers by gender. The CBS SNP may be important in regulating plasma homocysteine and cystathionine levels that could theoretically mediate the aberrant DNA methylation in smokers at high risk to develop lung cancer. Grant Support: This work is supported by K01CA128823 NCI (Flores) and R01CA097356 NCI (Belinsky).

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 2633. doi:1538-7445.AM2012-2633
Abstract 2636: Nonmelanoma skin cancer as a marker of a cancer-prone phenotype: Potential role of DNA repair gene variants
Authors: Ruczinski Ingo , Jorgensen Timothy , Shugart Yin Yao , Berthier-Schaad Yvette , Kessing Bailey , Hoffman-Bolton Judithh , Helzlsouer Kathy , Kao W.H. Linda , Wheless Lee , Francis Lesley , Alani Rhoda , Strickland Paul , Smith Michael , Alberg Anthony J.
Published: August 2012

Purpose: For unknown reasons, nonmelanoma skin cancer (NMSC) is associated with increased risk of other malignancies. This study tested the hypothesis that DNA repair gene variants contribute to the increased cancer risk associated with a personal history of NMSC. Methods: From the parent CLUE II cohort study, established in 1989 in Washington County MD, the study consisted of a cancer-free control group (n=2,296) compared to three mutually exclusive groups of cancer cases ascertained through 2007: 1) Other (non-NMSC) cancer only (n=2,349); 2) NMSC only (n=694); and 3) NMSC plus other cancer (n=577). The frequency of minor alleles in 759 DNA repair single nucleotide polymorphisms (SNPs) was compared in these four groups. Results: Comparing those with both NMSC and other cancer versus those with no cancer, 10 SNPs had additive model p-values<0.01. The two top-ranked SNPs were both within the thymine DNA glycosylase gene (TDG). One was a nonsynonymous coding SNP (rs2888805) (per allele odds ratio (OR) 1.40, 95% confidence interval (CI) 1.16-1.70; p-value=0.0006) and the other was an intronic SNP in high linkage disequilibrium with rs2888805 (rs4135150). Conclusion: The results pinpoint DNA repair genes most likely to contribute to the NMSC cancer-prone phenotype. A promising lead is genetic variants in TDG, important not only in base excision repair but also in regulating the epigenome and gene expression, which may contribute to the NMSC-associated increase in overall cancer risk.

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 2636. doi:1538-7445.AM2012-2636
Abstract 2641: Polymorphisms in pattern recognition genes in the innate immunity system and risk of non-Hodgkin lymphoma
Authors: Hu Wei , Xu Jun , Bassig Bryan A. , Zheng Tongzhang , Zhang Yawei , Berndt Sonja I. , Holford Theodore R. , Hosgood H. Dean , Leaderer Brian , Menashe Idan , Boyle Peter , Chanock Stephen , Lan Qing , Rothman Nathaniel
Published: August 2012

The pattern recognition pathway plays an important role in infection recognition and immune responses, and previous studies have suggested an association between genetic variation in innate immunity genes and non-Hodgkin lymphoma (NHL). We evaluated NHL risk associated with the common genetic variation in pattern recognition genes using data from a case-control study of NHL conducted in Connecticut women. Single nucleotide polymorphisms (SNPs) in 27 pattern recognition genes were genotyped in 432 Caucasian incident NHL cases and 494 frequency-matched controls. Unconditional logistic regression was used to compute odds ratios (ORs) for NHL and four major NHL subtypes in relation to individual SNPs and haplotypes. A gene-based analysis that adjusted for the number of tagSNPs genotyped in each gene showed significant association with overall NHL for the MBP gene (p=0.028), with DLBCL subtype for the MASP2 gene (p=0.011), and with FL subtype for the DEFB126 (p=0.041). A SNP-based analysis showed that MBP rs8094402 was associated with decreased risks of overall NHL (allele risk OR=0.72, p-trend=0.0018), DLBCL (allele risk OR=0.72, p-trend=0.036), and FL (allele risk OR=0.67, p-trend=0.021). MASP2 rs12711521 was associated with a decreased risk of DLBCL (allele risk OR=0.57, p-trend=0.0042). We also observed an increased risk of FL for DEFB126 rs6054706 (allele risk OR=1.39, p-trend=0.033). Our results are suggestive of a potential role of the pattern recognition in susceptibility to NHL but require replication in larger studies.

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 2641. doi:1538-7445.AM2012-2641
Abstract 2643: Interactions between polycyclic aromatic hydrocarbon exposure and genetic polymorphisms on benzo(a)pyrene-DNA adducts in a Polish cohort of mothers and newborns
Authors: Iyer Shoba , Xiong Wei , Tang Deliang , Jedrychowski Wieslaw , Chanock Stephen , Wang Shuang , Stigter Laura , Mroz Elzbieta , Perera Frederica
Published: August 2012

Background Polycyclic aromatic hydrocarbons (PAHs) are a class of chemicals common in the environment. Major sources of PAHs include fossil fuel combustion and cigarette smoking. Certain PAHs are carcinogenic, though the degree to which genetic variation influences susceptibility to PAH exposure remains unclear. Benzo(a)pyrene (BaP) is a well-studied PAH that is classified as a probable human carcinogen. Here, we evaluated single nucleotide polymorphism (SNP) frequency in genes related to PAH metabolism and detoxification, and explored the interactions between PAH exposure and SNPs on BaP-DNA adducts, an established cancer risk marker, in umbilical cord white blood cells (WBCs). Methods Maternal and umbilical cord blood were collected at delivery from participants in a longitudinal cohort study of Polish mothers and newborns in Krakow, Poland. WBC DNA was isolated from cord blood, and genetic polymorphisms and BaP-DNA cord adducts were then measured in 503 mothers and 445 newborns. Maternal PAH exposure was measured during pregnancy with a personal air exposure monitor. For this study 7 maternal and newborn genes related to PAH metabolism, detoxification and repair were selected for SNP analyses: CYP1A1, CYP1A2, CYP1B1, GSTM3, GSTT2, NQO1 and XRCC1. SNP x PAH interactions on logarithmic (ln)-transformed BaP-DNA adduct levels were explored. Results We observed a number of significant interactions between high PAH exposure and SNPs in both mothers and newborns on BaP-DNA adducts in cord blood. For example, the interaction between a CYP1A2 SNP (rs2069514) and high PAH exposure on cord BaP-DNA adducts in newborns was significant (α=−1.34, p<0.01). We will present significant interaction results from analyses performed on both maternal and newborn CYP1A1, CYP1A2, GSTM3, GSTT2, NQO1 and XRCC1 SNPs. Discussion It is biologically plausible that an individual's abilities to metabolically activate and detoxify BaP and repair DNA damage play a role in susceptibility to DNA adduct formation following prenatal PAH exposure. Ultimately, this susceptibility could correlate with future risk of cancer development. Our findings of several SNP x PAH exposure interactions on cord BaP-DNA adducts support the hypothesis that genetic variability can contribute to susceptibility and potential cancer risk from prenatal PAH exposures.

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 2643. doi:1538-7445.AM2012-2643
Abstract 2650: A combined bioinformatics and GWAS approach identifies a functional 3′UTR insertion/deletion in YES1 associated with bladder cancer risk
Authors: Wei Hua , Hildebrandt Michelle AT , Gu Jian , Ye Yuanqing , Huang Maosheng , Dinney Colin P. , Wu Xifeng
Published: August 2012

Bladder cancer (BC) is diagnosed in over 70,000 individuals each year and its incidence is rising. There is a need for biomarkers to identify those at high risk, as well as for early detection. Large genome-wide association studies have identified multiple susceptibility loci; however, individually and combined, these variants only explain a small portion of the variation in BC risk. One possibility to explain the missing heritability is the effect of small insertions and deletions (INDELs). Because of the nature of these variations, they have a high likelihood for functional effects. Therefore, the purpose of study was to determine whether common INDELs are associated with BC risk. We retrieved 0.73 million INDELs and 7.72 million single nucleotide polymorphisms (SNPs) from the 1000 Genomes Pilot Project. Tagging-SNPs were identified for 0.48 million of these INDELs with r2 > 0.80 by PLINK. We then evaluated each tagging-SNP for association with BC risk in 969 BC cases and 957 controls. Using this approach, 5,110 INDELs were shown to be associated with BC risk (P < 0.05). We next focused on potentially functional INDELs located in exons, 3′ UTRs, 5′ UTRs or promoters. Approximately 50 INDELs fit this criterion, with a 2 basepair INDEL rs56342716 (-/AT) located in the 3′ UTR of YES1, a src kinase oncogene, being highly significant. The tagging-SNP for this INDEL, rs3786347, was associated with a 1.27-fold increase in BC risk (OR 1.27, 95% CI, 1.10-1.43, P = 6.08x10−4). These results were confirmed by direct genotyping of the INDEL in 822 BC cases and 802 healthy controls (OR 1.20, 95% CI, 1.04-1.38, P = 0.01). Reporter gene assay results revealed that the variant allele (AT) of rs56342716 disrupted the inhibitory effects of three microRNAs (miR-548e, miR-548f, and miR-548a-3p), providing a potential biological mechanism for the association with BC risk through increased YES1 levels. Together, these results provide evidence supporting a connection between a functional INDEL and BC risk while implicating YES1 in bladder cancer pathogenesis through a microRNA-mediated mechanism.

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 2650. doi:1538-7445.AM2012-2650
Abstract 2697: Role of a novel flavonoid enriched in ocimum sanctum linn for prostate cancer chemoprevention and therapy
Authors: Singhal Sharad S. , Nagaprashantha Lokesh , Singhal Jyotsana , Awasthi Sanjay
Published: August 2012

The present study was conducted to determine the efficacy of novel flavonoid vicenin-2 (VCN-2), an active constituent of the medicinal herb Ocimum Sanctum Linn or Tulsi, as a single agent and in combination with docetaxel (DTL) in carcinoma of prostate (CaP). VCN-2 effectively induced anti-proliferative, anti-angiogenic and pro-apoptotic effect in CaP cells (PC-3, DU-145 and LNCaP) irrespective of their androgen responsiveness or p53 status. VCN-2 inhibited EGFR/Akt/mTOR/ p70S6K pathway along with decreasing c-Myc, cyclin D1, cyclin B1, CDK4, PCNA and hTERT in vitro. VCN-2 reached a level of 2.6 + 0.3 μM in serum after oral administration in mice which reflected that VCN-2 is orally absorbed. The i.v. administration of docetaxel (DTL), current drug of choice in androgen-independent CaP, is associated with dose-limiting toxicities like febrile neutropenia which has lead to characterization of alternate routes of administration and potential combinatorial regimens. In this regard, VCN-2 in combination with DTL synergistically inhibited the growth of prostate tumors in vivo with a greater decrease in the levels of AR, pIGF1R, pAkt, PCNA, cyclin D1, Ki67, CD31, and increase in E-cadherin. VCN-2 has been investigated for radio-protection and anti-inflammatory properties. This is the first study on the anti-cancer effects of VCN-2. In conclusion, our investigations collectively provide strong evidence that VCN-2 is effective against CaP progression along with indicating that VCN-2 and DTL co-administration is more effective than either of the single agents in androgen-independent prostate cancer. (Supported in part by NIH grant CA 77495)

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 2697. doi:1538-7445.AM2012-2697
Abstract 2715: Treatment of disseminated HER-2 carcinomas with a HER-2-retargeted oncolytic herpes virus
Authors: Lollini Pier-Luigi , Menotti Laura , Giovanni Carla De , Ianzano Marianna , Palladini Arianna , Grosso Valentina , Croci Stefania , Nicoletti Giordano , Landuzzi Lorena , Gatta Valentina , Fiume Gabriella Campadelli , Nanni Patrizia
Published: August 2012

Oncolytic viruses hold the promise to spare normal cells and to selectively seek and destroy tumor cells within the body. Until now numerous viruses where successfully engineered to confer or enhance tumor selectivity, however the effective targeting of disseminated tumor cells in vivo remains a major hurdle. We have retargeted herpes simpex virus (HSV) through the replacement of key gD sequences with sequences encoding a HER-2-specific single chain antibody derived from trastuzumab. The HER-2 retargeted virus (designated here as HER2-HSV) did not bind HSV natural receptors (HVEM and nectin-1), and exclusively infected and killed tumor cells expressing high levels of human HER-2 oncoprotein p185 (PNAS, 106: 9039, 2009). Intratumor injection of HER2-HSV inhibited the growth of HER-2+ human ovarian and breast carcinomas in immunodeficient mice. The aim of the present work was to assess the curative potential of HER2-HSV against disseminated tumors in realistic mouse models reflecting tumor spread in human patients. Human ovarian carcinoma SK-OV-3 cells implanted intraperitoneally in immunodeficient Rag2−/−;Il2rg−/− mice give rise to a progressive peritoneal carcinomatosis similar to the fatal condition developing in advanced human patients. Intraperitoneal (i.p.) administrations of HER2-HSV (108 pfu weekly for 4 weeks) strongly inhibited carcinomatosis resulting in 60% of mice free from peritoneal diffusion, and 95% reduction in the total weight of neoplastic nodules. Visceral organs are a common target of metastatic spread of breast cancer, therefore we studied whether HER2-HSV administred i.p. could treat visceral metastases of HER-2+ MDA-MB-453 breast carcinomas in Rag2−/−;Il2rg−/− mice. The incidence of ovarian metastases was reduced from 89% to 30% by HER2-HSV treatment. Interestingly, the antimetastatic activity of HER2-HSV was not confined to the peritoneal cavity. In the same mice we found also a significant reduction in brain metastases but not in bone marrow infiltration. In practice, HER2-HSV administered i.p. inhibited both visceral (ovary) and distant (brain) HER-2+ breast cancer metastases, presumably reflecting both intraperitoneal diffusion of the virus and the neurotropism of herpesviruses. We are currently studying whether the intravenous administration of HER2-HSV could achieve a more widespread control of metastatic growth.In conclusion, the results show that a HER-2-redirected oncolytic herpesvirus could effectively target disseminated ovarian and breast carcinomas.

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 2715. doi:1538-7445.AM2012-2715
Abstract 2717: Reolysin: A novel reovirus-based agent that induces endoplasmic reticular stress in RAS-activated pancreatic cancer
Authors: Carew Jennifer S. , Espitia Claudia M. , Kelly Kevin R. , Coffey Matt , Freeman James W. , Nawrocki Steffan T.
Published: August 2012

Mutations in the RAS oncogene are associated with transformation and proliferation and are prevalent in many tumor types. Since RAS is frequently hyperactivated in pancreatic cancer and plays an essential role in tumor progression, it is an ideal therapeutic target. Reoviruses are naturally occurring viruses that are non-pathogenic and have been reported to specifically replicate in cancer cells with an activated RAS pathway, but not in normal tissue. To take advantage of this observation therapeutically, the reovirus-based anticancer agent Reolysin was recently developed. Reolysin has already progressed into clinical trials, but its mechanisms of action have not been fully elucidated. We hypothesized that Reolysin exposure would result in the production of viral products, stimulate endoplasmic reticular (ER) stress, and induce apoptosis. Reolysin treatment triggered the selective replication of reoviruses as visualized by immunocytochemistry and electron microscopy in KRAS-transformed immortalized human pancreatic duct epithelial cells and in a panel of pancreatic cancer cell lines. Reovirus accumulation was associated with an increase in the expression of ER stress-related genes as assessed by microarray and quantitative RT-PCR analyses, cleavage of caspase-4, and induction of apoptosis. In support of our hypothesis that Reolysin induces ER stress-mediated apoptosis, co-treatment with tunicamycin or brefeldin A further augmented Reolysin-induced cell death. Previous studies have demonstrated that the proteasome inhibitor bortezomib causes ER stress-mediated apoptosis. Here we show that co-treatment with bortezomib and Reolysin stimulates the simultaneous accumulation of ubiquitinated and viral proteins resulting in enhanced levels of ER stress-related gene expression, caspase-4 cleavage, and apoptosis. The role of caspase-4 as a regulator of therapeutic sensitivity to these agents was investigated by targeting caspase-4 expression with siRNA. Knockdown of caspase-4 blunted apoptosis stimulated by Reolysin, bortezomib, and the combination. Importantly, bortezomib also dramatically augmented the anticancer activity of Reolysin in xenograft models of pancreatic cancer in vivo. Analysis of tumor specimens from mice treated with Reolysin and bortezomib displayed reovirus accumulation, enhanced expression of GRP78/Bip, a marker of ER stress and increased levels of apoptosis. Collectively, our results demonstrate that the abnormal protein accumulation induced by Reolysin and bortezomib promotes heightened ER stress and apoptosis in pancreatic 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 2717. doi:1538-7445.AM2012-2717
Abstract 2800: Dual PI3K/mTOR inhibitor NVP BEZ-235 suppresses translation of hypoxia-inducible factor (HIF)-1α and increases cell death under hypoxia
Authors: Karar Jayashree , Cerniglia George J. , Koumenis Constantinos , Maity Amit
Published: August 2012

Our goal was to investigate the effects of the Novartis compound NVP-BEZ235, a dual PI3K/mTOR inhibitor, on hypoxia-inducible factor-1 alpha (HIF-1α) expression. NVP-BEZ235 was much more potent than either the mTOR inhibitor rapamycin or the PI3K inhibitor LY294002 in blocking the hypoxic induction of HIF-1α in vitro, due to decreased protein translation. 7-methyl GTP chromatography showed that NVP-BEZ235 led to a robust recruitment of 4E-BP1 to eIF4E and a near absence of binding of eIF4G, consistent with inhibition of protein translation. NVP-BEZ235 also decreased expression of several proteins regulated by eIF4E including cyclin B1 and D1, survivin, and vascular endothelial growth factor. NVP-BEZ235 specifically decreased eIF4G but not eIF4E expression. As HIF-1α has been associated with adaptation under hypoxia, we examined the effect of NVP-BEZ235 on cell survival in low pO2 conditions. The drug increased killing of cells under hypoxia as measured by both short-term (MTT) and long-term (clonogenic) assays. To understand the mechanism behind this observation, we performed immunoblotting for factors associated with cell survival. In normoxia, Akt S473 phosphorylation decreased within an hour of NVP-BEZ235 treatment, but then increased by 24 hours. In contrast, under hypoxia, NVP-BEZ235 caused a prolonged suppression of Akt phosphorylation. Furthermore, we found a greater increase in PARP cleavage in hypoxic cells treated 1-16 hours after drug treatment than in normoxic cells, consistent with increased apoptosis. This was confirmed using an ELISA assay that measures cytoplasmic oligonucleosomes. We also found that NVP-BEZ235 increases autophagy as measured by (i) LC3-I to LC3-II conversion on immunoblotting, (ii) degradation of p62 and (iii) GFP-LC3 subcellular localization detected by immunofluorescence. Treatment of cells with the drug under hypoxia further increased autophagy, although it is unclear at this point whether this actually contributes to cell death or is a pro-survival mechanism. In conclusion, we have found that NVP-BEZ235 blocks HIF-1α induction and increases cell killing under hypoxia, which may have important implications for the use of this drug in cancer therapy.

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 2800. doi:1538-7445.AM2012-2800
Abstract 2806: BRAF and MEK inhibitor profiling across 240 tumor cell lines to correlate with sensitivity and resistant biomarkers
Authors: Bernards Karen , Ovechkina Yulia , Cheng Jushun , Kushleika John , Angione Alison , Hnilo James , O'Day Christine
Published: August 2012

Activated kinases that induce cell proliferation have been attractive targets for targeted cancer therapy development. Cancer cells could become dependent on tumor-specific activated kinases and this tendency has been coined oncogene addiction. Here, we investigated three activated kinase inhibitors: BRAF inhibitor, PLX-4032 analog, and the MEK inhibitors, CI1040 and PD0325901. We established a high throughput cellular approach to profile 240 human tumor cell lines identifying genotype-correlated sensitivity or resistance. Proliferative, apoptotic and cell cycle arrest responses were measured using multiplexed high content screening with automated fluorescence microscopy and image analysis based technology. Growth index was measured using nuclear dye. Activated caspase 3 antibodies were used for the apoptosis induction detection. Phospho-histone H3 antibodies were used to measure the cell cycle block. We generated cell line profiles to reveal drug sensitivity and resistance patterns that may correlate with the clinical genotype responses. Cell lines with BRAFV600E mutations showed overlapping sensitivity to all three MEK and BRAF inhibitors. RAS mutations confer resistance to the BRAF inhibitor and confer sensitivity to both MEK inhibitors. In addition, we used Alphascreen technology to measure phosphoERK across the 240 non-treated tumor cell line panel. We found that the majority of PLX-4032 sensitive cell lines expressed high levels of phosphoERK. In addition, we investigated BRAF, MEK and EGFR inhibitor combinations to evaluate potential synergies. This preclinical approach can be used to predict mechanisms of susceptibility or resistance to these agents which in turn could be used for the optimization of targeted cancer therapeutics.

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 2806. doi:1538-7445.AM2012-2806
Abstract 2823: PHA-739358, a pan-Aurora kinase inhibitor, induces apoptosis and inhibits invasion in melanoma cell lines
Authors: Xie Lifang , Meyskens Frank
Published: August 2012

Cutaneous melanoma (CM) is the most lethal form of skin cancer and is highly invasive and markedly resistant to conventional therapy. The incidence of malignant melanoma has been increasing worldwide for the past three decades, however, the standard care for patients with metastatic melanoma has not changed significantly, therefore, new strategies for treatment of metastatic melanoma are urgently needed. Significant insights have recently been gained into the molecular events underpinning the development of melanoma. Aurora kinases play an essential role as key mitotic regulators, controlling chromosome alignment, segregation, centrosomal maturation, mitotic spindle formation, and cytokinesis during mitosis, and are frequently overexpressed in various human cancers including that of CM making them ideal targets for anti-cancer therapy. Several small molecule inhibitors of the aurora kinases have been developed and tested in vivo and in vitro, and some of them have shown promising clinical efficacy in a number of early phaseI/II clinical trials. Among those, one of the most advanced clinical compounds currently is PHA-739358 (PHA). The goal of this study is to investigate the anti-proliferative and anti-invasive features of PHA in three melanoma cell lines including WM3211, Lu1205, and SK-Mel28. The results showed a time- and dose- dependent growth inhibition in all the cell lines tested with low μM IC50s upon PHA treatment, and significant induction of caspase activity was observed as well. FACScan cell cycle analysis showed significant induction of G2/M population of cells in all three cell lines and increased polyploidy proportion of cells in WM3211 cell line. For the first time, we showed that PHA inhibits melanoma cell invasion in a dose- and time- dependent manor using a Matrigel Invasion Assay. More interestingly, addition of PHA enhanced Temozolomide (TMZ)-induced caspase activation in melanoma cell lines indicating a potential combination therapeutic strategy for the treatment of melanoma. Thus, targeting aurora kianses with PHA is a promising therapeutic strategy administered alone or in combination with TMZ for patients with advanced stages of CM.

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 2823. doi:1538-7445.AM2012-2823
Abstract 2837: Assay development for the discovery of semaphorin 3B-inducing agents from natural product sources
Authors: Yong Yeonjoong , Pan Li , Ren Yulin , Kinghorn A. Douglas , Swanson Steven M. , de Blanco Esperanza J. Carcache
Published: August 2012

The family of semaphorins has been found to regulate cell adhesion and cell motility, the immune response, angiogenesis, and tumor progression. The semaphorins are emerging as regulators of key processes of tumor progression. Semaphorin 3B, in particular, has been found to inhibit proliferation and promote apoptosis. Since there is yet no screening assay available to be used in drug discovery for this crucial target, the present study focuses on the development of a new absorbance-based bioassay to search for new semaphorin 3B inducers from natural sources. Among the parameters considered include the type of cancer cell line, the time of incubation, the type of lysis buffer, secondary effects that affect absorbance levels, and ways to minimize false positives. Vitamin D and actinomycin are being used as controls in this assay. Vitamin D acts as a positive control since it is a semaphorin 3B inducer. Comparison of the levels of induction of the active substances to that of the positive control provides an indication about the level of potential a hit will have if being developed as a drug. Actinomycin inhibits transcription by binding to DNA at the transcription initiation level. When using actinomycin in this assay, its effect is considered to be proportional to that of semaphorin 3B inhibitors. Hence, actinomycin serves as a negative control to discriminate inducers from inhibitors of semaphorin 3B. The use of both controls, therefore, offers the opportunity to discover selective and highly potent semaphorin 3B inducers of natural origin. The assay has been standardized in a 96-well plate format to optimize sensitivity, selectivity, accuracy, robustness, and cost effectiveness. A library of natural product compounds isolated from higher plants, filamentous fungi, and cyanobacteria is currently being screened using this new bioassay. A total of 50 samples have been tested already with two samples exhibiting low induction levels. The most active substances will be further tested using a series of immunoblot secondary assays to validate the potential hits. Additionally, the screening assay presented could be modified to discover new small molecules or drug-like scaffolds as inhibitors or inducers of other semaphorins. Thus, an assay to identify compounds that selectively and potently affect this pathway may lead to new ways of understanding the cell signaling mechanism of these agents, which could be beneficial for the discovery of new natural product leads for cancer treatment. Program project grant P01-CA125066-S1 funded by the National Cancer Institute, NIH.

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 2837. doi:1538-7445.AM2012-2837
Abstract 284: 17β-estradiol-induced expression of αEF1 confers tamoxifen resistance in breast cancer
Authors: Guo Shaocong , Hu Fen , Gao Yang , Zhu Tianhui , Yang Shuang
Published: August 2012

Background: Resistance to tamoxifen therapy is one of the major barriers to the successful treatment of breast cancer, and ER-α expression is currently the main biomarker of response to tamoxifen treatment. Elucidating the regulation of ER-α expression may provide new therapeutic targets for overcoming tamoxifen resistance. Materials and Methods: Quantitative RT-PCR, immunoblotting, and immunofluorescence were used to determine 17β-estradiol-induced expression of αEF1 and ER-α at the mRNA and protein levels in the presence or absence of ICI 182,780, PI-103, PKI, or BAY 11-7082. Luciferase assay was used to determine αEF1-driven transcriptional activities of the wild-type and mutant human ER-α promoters. Quantitative CHIP assay was used to detect the direct association of αEF1 with the wild-type human ER-α proximal promoter. Immunohistochemistry was used to determine the expression of αEF1 and ER-α protein in breast cancer specimens. Results: We found that 17β-estradiol up-regulated αEF1 expression in a dose- and time-dependent manner in MCF-7 breast cancer cells. Down-regulation of the ER-α significantly abolished this effect, showing that 17β-estradiol-induced expression of αEF1 is ER-dependent. Blockade of the PI3K or NF-κB pathway resulted in an interference on the up-regulation of αEF1 by 17β-estradiol. Interestingly, ectopic expression of αEF1 exhibited a repression on ER-α expression in MCF-7 cells. Luciferase and CHIP assays further confirmed that αEF1 transcriptionally inhibited the promoter activity of human ER-α by binding to its E2-box (CACCTG). Importantly, up-regulation of αEF1 expression rendered MCF-7 cells less sensitive to tamoxifen treatment, whereas adding ER-α comprised the effect of αEF1 on the cell sensitivity to tamoxifen. Through the study of breast cancer specimens, we found a strong inverse correlation between αEF1 and ER-α protein expression, further supporting the contribution of estrogen/αEF1/ER cascade to tamoxifen resistance in breast cancer. Conclusions: Our data indicates a key role of αEF1 in developing tamoxifen resistance in breast cancer, by altering ER-α expression. Given that re-expressing ER-α in ER-α-negative breast cancer can restore tamoxifen sensitivity, restoring ER-α expression by inhibiting αEF1 provides a potential new strategy for overcoming endocrine resistance.

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 284. doi:1538-7445.AM2012-284
Abstract 2862: Deregulated GSK3β sustains gastrointestinal cancer cells by modulating hTERT and telomerase
Authors: Minamoto Toshinari , Mai Wei , Kyo Satoru , Shakoori Abbas , Miyashita Katsuyoshi , Yokoi Kenji , Shimasaki Takeo , Motoo Yoshiharu , Kawakami Kazuyuki
Published: August 2012

Purpose: Glycogen synthase kinase-3β (GSK3β) regulates multiple cell signaling pathways and has been implicated in glucose intolerance, neurodegenerative disorders, and inflammation. We investigated the expression, activity, and putative pathologic role of GSK3β in gastrointestinal, pancreatic, and liver cancers. Experimental Design: Colon, stomach, pancreatic, and liver cancer cell lines; nonneoplastic HEK293 cells; and matched pairs of normal and tumor tissues of stomach and colon cancer patients were examined for GSK3β expression and its phosphorylation at serine 9 (inactive form) and tyrosine 216 (active form) by Western immunoblotting and for GSK3β activity by in vitro kinase assay. The effects of small-molecule GSK3β inhibitors and of RNA interference on cell survival, proliferation, and apoptosis were examined in vitro and on human colon cancer cell xenografts in athymic mice. The effects of GSK3β inhibition on human telomerase reverse transcriptase (hTERT) expression and telomerase activity were compared between colon cancer and HEK293 cells. Results: Cancer cell lines and most cancer tissues showed increased GSK3β expression and increased tyrosine 216 phosphorylation and activity but decreased serine 9 phosphorylation compared with HEK293 cells and nonneoplastic tissues. Inhibition of GSK3β resulted in attenuated cell survival and proliferation and increased apoptosis in most cancer cell lines and in HT-29 xenografts in rodents but not in HEK293 cells. GSK3β inhibition in colon cancer cells was associated with decreased hTERT expression and telomerase activity. Conclusion: The results indicate that deregulated GSK3β sustains gastrointestinal cancer cells survival through modulation of hTERT and telomerase.

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 2862. doi:1538-7445.AM2012-2862
Abstract 2868: Pancreatic tumor stromal cells express high levels of α-glutamyl transferase that may be employed to deliver a metabolism inhibitor to the tumor mass
Authors: Ramsay Emma E. , Decollogne Stéphanie , Joshi Swapna , Corti Alessandro , Pompella Alfonso , Apte Minoti , Hogg Philip J. , Dilda Pierre J.
Published: August 2012

Tumors of the pancreas have the most prominent stromal/desmoplastic reaction of all epithelial tumors. This reaction is mediated by the cancer-associated stellate cells. These cells interact closely with pancreatic cancer cells to promote cancer cell survival, local tumor growth and distant metastasis (1). We have found that cancer-associated human pancreatic stellate cells express up to 30-fold higher levels of α-glutamyl transferase (≥GT) on their surface than normal pancreatic stellate cells. βGT catalyzes the transfer of the α-glutamyl moiety of glutathione to an acceptor that may be an amino acid, a peptide or water (forming glutamate). This observation suggests that this enzyme could be used to deliver a αGT-activated prodrug to the tumor mass. We have tested this theory using the glutathionylated arsenical, GSAO. GSAO is converted to GCAO by cell surface αGT, which then crosses the plasma membrane and inactivates the mitochondrial inner-membrane transporter, adenine nucleotide translocase (2). The mitochondrial perturbation leads to proliferation arrest and then cell death. GSAO was converted to GCAO by cancer-associated stellate cells and this metabolism was blocked by the αGT inhibitor, ABBA. The activated GSAO inhibited proliferation of both tumor and endothelial cells by 43 to 100% and 41 to 75%, respectively. We also observed a positive correlation (R2=0.883) between the αGT activity of pancreatic tumor cells and proliferation arrest of co-cultured endothelial cells by GSAO. We have established an orthotopic model of human pancreatic cancer in mice where tumor cells are implanted without or with cancer-associated stellate cells. The anti-tumor efficacy of systemically administered GSAO is currently being evaluated in this model. These observations suggest that the high expression of αGT on pancreatic tumor stromal cells may be employed to deliver a αGT-activated prodrug to the tumor mass. 1. Vonlaufen, A., Phillips, P. A., Xu, Z., Goldstein, D., Pirola, R. C., Wilson, J. S., and Apte, M. V. (2008) Cancer Res. 68, 7707-7710 2. Dilda, P. J., Ramsay, E. E., Corti, A., Pompella, A., and Hogg, P. J. (2008) J. Biol. Chem. 283, 35428-35434

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 2868. doi:1538-7445.AM2012-2868
Abstract 2878: Anticancer effects of c-Met inhibitors in esophageal squamous cell carcinoma
Authors: Tzao Ching , Wang Chun-Ya , Lee Meng-Ching , Chen Ban-Hen , Sun Guang-Huan
Published: August 2012

Background: c-Met is a receptor tyrosine kinase (RTK) that has been shown to be a potential target of therapy in a variety of human cancers. We investigated if c-Met served as a potential therapeutic target in esophageal squamous cell cancer (ESCC). Methods: Cytotoxicity (MTT) assay, cell migration assay and cell cycle analysis by flow cytometry were conducted in KYSE 510 and 170 ESCC cell lines (kindly provided by Dr. Yutaka Shimada) in response to various concentrations of c-met inhibitors, SU11274 and PHA665752. Apoptosis of ESCC cell lines was detected by TUNEL assay. Cell cycle regulatory proteins, cyclin A and B1, tumor suppressors including Rb, p53 p21 and p27, and intrinsic apoptotic factors were determined by Western blot analysis. Mice inoculated with KYSE 170 ESCC cell line were used to test therapeutic response of c-met inhibitors in vivo. Results: SU11274 and PHA665752 significantly suppressed viability and migration of KYSE 170 and 510 ESCC cells with decreased expression of phosphorylated c-Met (p-c-Met). Expression of p21, p27, p53 and Rb was upregulated in ESCC cell lines treated with c-Met inhibitors while inducing G1/G2 cell cycle arrest and apoptosis. Tumor growth in vivo was significantly suppressed in response to treatment with c-Met inhibitors with decreased expression of p-c-Met within the mice tumors. Conclusion: c-Met inhibitors exerted significant anticancer effects in vitro and in vivo for ESCC cell lines, suggesting that c-Met may serve as a potential therapeutic target for ESCC.

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 2878. doi:1538-7445.AM2012-2878
Abstract 2882: Therapeutic effects of ormeloxifene on cervical cancer
Authors: Chauhan Neeraj , Maher Diane M. , Yallapu Murali M. , Ebeling Mara C. , Jaggi Meena , Chauhan Subhash C.
Published: August 2012

Background: Cervical cancer is one of the most common and deadly cancers among women worldwide and is strongly associated with persistent Human Papillomavirus (HPV) infection. HPV E6/E7 oncoproteins are well known to interfere with p53 and retinoblastoma (Rb) proteins and drive the development of cervical cancer. While screening for cervical cancer can reduce the incidence and mortality, treatment of advanced stage cervical cancer is difficult and often unsuccessful. Therefore, there is an urgent need for the development of additional treatment modalities. Ormeloxifene is a non-hormonal anti-estrogen oral contraceptive for human use and it effectively suppresses the highly proliferative decidual cells in the endometrium to inhibit egg implantation. Considering its strong anti-proliferative effect, we hypothesized that ormeloxifene may inhibit the growth of cervical cancer cells and may suppress the expression of HPV oncoproteins E6/E7. Methods: The effect of ormeloxifene on the proliferation of various cervical cancer cell lines (Caski, SiHa, C33A, and HT3) was determined by MTS and colony formation assay. Annexin V/7AAD and propidium iodide (PI) staining was analyzed by flow cytometry to determine ormeloxifene's effect on apoptosis and cell cycle inhibition, respectively. The expression of apoptotic proteins such as poly (ADP-ribose) polymerase (PARP), Caspase 3 and Caspase 9 was determined by immunoblotting. The potential of ormeloxifene to repress the expression of HPV E6/E7 oncogenes was determined by quantitative RT-PCR and immunoblotting analyses. Further, the efficacy of ormeloxifene to restore tumor suppressor proteins, such as p53 and Rb, was also determined by immunoblotting. Results: In all 4 cell lines, ormeloxifene effectively inhibited cervical cancer cell growth. Ormeloxifene treatment induced apoptosis in cervical cancer cells as determined by staining for Annexin V/7AAD and immunoblotting for cleaved PARP, Caspase 3, and Caspase 9. PI staining also clearly revealed that ormeloxifene treatment arrests Caski cells in the G0-G1 phase. Additionally, ormeloxifene treatment caused a marked decrease in the levels of HPV E6 and E7 oncogenes and restored the levels of p53 and Rb proteins in Caski cells. Conclusion: Our findings show that ormeloxifene significantly inhibits cervical cancer cell growth and down-regulates HPV E6/E7 oncogenes, therefore; ormeloxifene may be novel chemo-preventive and treatment method for the management of cervical 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 2882. doi:1538-7445.AM2012-2882
Abstract 2886: Carbon nanotube-mediated siRNA for gastrin-releasing peptide receptor silencing in neuroblastoma
Authors: Qiao Jingbo , Hong Tu , Paul Pritha , Lee Sora , Triana Taylor , Xu Ya-qiong , Chung Dai H.
Published: August 2012

Small interfering RNA (siRNA) has the potential to influence gene expression with a high degree of target gene specificity, making siRNA-mediated therapeutic approaches very promising in biomedicine. However, the clinical applications of siRNA therapeutics have been impeded by its poor intracellular uptake, instability in vivo, and non-specific immune stimulations. In this study, we have aimed to resolve these difficulties in the applications of siRNA, we developed a magneto-fluorescent carbon nanotube (CNT) platform to deliver siRNA into neuroblastoma and down-regulate gastrin-releasing peptide receptor (GRP-R) expression in vitro and in vivo. METHODS. Human neuroblastoma BE(2)-C cells were used in this study. siRNA oligos were custom synthesized by Thermo Scientific (Dharmacon). CNTs were produced by a high-pressure CO (HiPco) at Rice University. PEG-N (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy (polyethylene glycol)-5000]) was purchased from Avanti Polar Lipids Inc. (Alabaster, AL). Target gene expression was measured with Western blotting and immunohistochemical staining. siRNA stability was examined by agarose gel. The cytotoxicity of CNT was evaluated by measuring cell viability. RESULTS. We have developed a magneto-fluorescent carbon nanotube (CNT) platform to deliver siRNA into neuroblastoma and to down-regulate GRP-R expression in vitro and in vivo. We have systematically investigated the optical and magnetic properties of CNTs with different functional groups and have found that the functional groups on CNTs play an important role on the magnetic resonance imaging (MRI) and near-infrared fluorescence (NIRF) imaging of CNTs. Moreover, we have shown that CNT-mediated siRNA (CNT-siRNA) can silence GRP-R with efficiency up to 92%, which is much higher than that of siRNA mediated by the commercial transfection reagent, and effectively reduce downstream targets of GRP-R. This high efficiency may result from the enhanced stability of CNT-siRNA after transfection. We have also demonstrated the universal siRNA delivery efficiency by knocking down AKT2 in neuroblastoma cells and GRP-R in human breast cancer cells. In addition, we have found that CNT-siRNA can significantly silence GRP-R in in vivo subcutaneous mouse models. CONCLUSIONS. Our findings demonstrate that functionalized-CNTs mediated siRNA delivery caused high gene silencing efficiency of in vitro and in vivo. In addition, our results showed CNT produced MRI and NIRF imaging in cells. These fundamental studies offer a way to develop a multifunctional CNT delivery system with INTRINSIC MRI and NIRF imaging to evaluate the treatment effect simultaneously.

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 2886. doi:1538-7445.AM2012-2886