bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2739: DNA repair genotype-phenotype correlation and interplay between different DNA repair pathways
Authors: Allione Alessandra , Guarrera Simonetta , Polidoro Silvia , Rosa Fabio , Ricceri Fulvio , Voglino Floriana , Russo Alessia , Gaetano Cornelia Di , Simonelli Valeria , Mazzei Filomena , Porcedda Paola , Giachino Claudia , Vineis Paolo , Dogliotti Eugenia , Matullo Giuseppe
Published: June 2012

Individual DNA repair capacity is modulated by the genetic background to which hundreds of single nucleotide polymorphisms (SNPs) or haplotype combinations in DNA repair genes are likely to contribute. A large number of studies have been published on the association between DNA repair gene polymorphisms and cancer risk, whereas only few small studies investigated the relation between DNA repair phenotypic assays and cancer risk or DNA repair polymorphisms. In order to identify functional SNPs/haplotypes modulating DNA repair phenotypes and to investigate their potential impact on cancer risk, we have performed a genotype-phenotype correlation study evaluating levels of DNA damage and DNA repair capacity in blood cells treated at low doses of different DNA damaging agents. We investigated the association between genotypes/haplotypes and the DNA repair capacity measured with the following DNA repair phenotypic assays on cryopreserved lymphocytes from 225 healthy individuals: Comet assay after treatment with BPDE, phosphorylation of histone H2AX after treatment with γ-rays, OGG1 glycosylase activity, OGG1 and ERCC1 expression levels. Sixty-five DNA repair genes and a total of 768 SNPs have been selected and analysed on the 225 DNA samples by using a custom GoldenGate SNP chip (Illumina). Genotype-phenotype correlation analysis identified some new possible functional variants and haplotypes. We also tested gene-gene interactions, comparing results with existing prior knowledge from different publicly available databases and crossing functional evidence with information on gene expression levels and protein-protein interaction. A confirmation of some already described interplays between different DNA repair pathways have been obtained from SNP analysis and a suggestion of new possible cross-talks have been identified that need further experimental validation. Our results can contribute to identify subjects carrying combinations of less efficient DNA repair variants/haplotypes possibly at increased cancer risk or who can better benefit from anti-cancer therapies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2739. doi:10.1158/1538-7445.AM2011-2739
Abstract 2741: Applying a biological pathway-based approach to interrogate the genome-wide association data on prostate cancer
Authors: Feng Junjie , Sun Jielin , Zhang Zheng , Zhu Yi , Xu Jianfeng
Published: June 2012

Genome-wide association studies (GWAS) have been successful in identifying common susceptibility loci for several complex diseases, yet the massive amounts of data generated from GWAS have not been maximally leveraged. We have applied a previously reported pathway-based approach to analyze the prostate cancer (PCa) GWAS data from the Cancer Genetic Markers of Susceptibility (CGEMS) project. This approach examines whether the cumulative contribution of a set of SNPs that occur on genes within a predefined biological pathway is greater than expected by chance, and thus may provide important novel biological insights that have been missed by most current GWAS. Out of the 555 pathways analyzed from the Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology, and BioCarta databases, a total of 32 pathways reached a nominal P < 0.05 in their associations with PCa. Among these notably include six KEGG-defined cancer pathways (thyroid, prostate, renal, and pancreatic cancer, non-small cell lung cancer, and acute myeloid leukemia), three well-established cancer-related molecular pathways (ATR-BRCA, ionizing radiation response, and apoptosis), and three pathways that have cancer implications (glycolysis, calcium-dependent cell-cell adhesion, and regulation of actin cytoskeleton), which together constitute more than one third of the top-ranked pathways. Of closest relevance is the prostate cancer pathway (hsa05215), which was ranked the third highest (nominal P = 0.01) in our analysis. However, no associations of these top pathways remained significant after correction for multiple testing, indicating that the common variants involved in PCa risk are likely to occur in genes from multiple pathways. This genome-wide pathway analysis supports a model that alterations from multiple pathways may combinatorially contribute to the etiology of PCa.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2741. doi:10.1158/1538-7445.AM2011-2741
Abstract 2747: Application of a novel multi-locus test for genetic association incorporating gene-gene interaction suggests functionality for multiple susceptibility loci for prostate cancer
Authors: Ciampa Julia G. , Holmes Chris , Chatterjee Nilanjan
Published: June 2012

The discovery of gene-gene interactions in genome-wide association studies (GWAS) can generate hypotheses about the biologic process through which multiple susceptibility loci influence the pathogenesis of disease. We present an extension of a previously proposed score-test for disease association that allows for interaction between sets of biologically similar single nucleotide polymorphism (SNPs). The score-test gains power over alternative methods by incorporating a parsimonious one-degree-of-freedom model for gene-gene interaction. Our proposed extension allows for additional power gains in case-control studies via use of a retrospective likelihood that can exploit an assumption of gene-gene independence for the underlying population between unlinked sets of SNPs. Simulation studies were used to validate the performance of this method. It was found to maintain type I error and to gain power over alternative methods. We used it in a prostate cancer (PRCA) application with data from Stage II of the Cancer Genetic Markers of Susceptibility GWAS that includes 27,383 SNPs in 3941 cases and 3964 controls. We performed two genome scans, conditioning on established susceptibility SNPs for PRCA. Both analyses identified a high-ranking SNP notable for its biology and worthy of follow-up study. The first scan involved a sub-region of 8q24 that contains independent susceptibility loci specific to PRCA, as well as androgen-receptor (AR) binding sites and androgen-responsive enhancer elements. The analysis highlights rs748120 intronic to NR2C2 which produces an AR co-regulator such that, when NR2C2 binds AR, expression of their target genes decreases. The observed interaction suggests NR2C2 may contribute to the androgen sensitivity of this 8q24 gene desert in the etiology of PRCA. The second scan involved the JAZF1 and HNF1B genes regions that are associated with both PRCA and type 2 diabetes, which itself is associated with PRCA risk. The analysis highlights rs4810671 intronic to SULF2 which has demonstrated oncogenic properties in several cancers. It is regulated by insulin, the hormone thought to mediate the association of type 2 diabetes with PRCA. The observed interaction suggests abnormal insulin function may affect PRCA risk through dysregulation of SULF2. In summary, we propose an innovative multi-locus test for disease association that gains power over alternative methods and we describe promising results from a PRCA GWAS that suggest functionality for susceptibility regions.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2747. doi:10.1158/1538-7445.AM2011-2747
Abstract 2750: Associations between genetic variability in folate metabolism and breast cancer survival
Authors: Das Nandita , Baumgartner Kathy B. , Kerber Richard A. , Rai Shesh N. , Ulrich Cornelia M. , Neuhouser Marian L. , Bernstein Leslie , Tiernan Anne Mc , Ballard-Barbash Rachel , Baumgartner Richard N.
Published: June 2012

Methylenetetrahydrofolate reductase(MTHFR) is a key enzyme in folate metabolism that is critical for DNA methylation, synthesis and repair. Since genetic polymorphisms may modify the efficiency of this enzyme, we tested the hypothesis that MTHFR modifies breast cancer (BC) survival using data from the Health, Eating, Activity and Lifestyle (HEAL) Study for 772 incident primary invasive cases (Stage I-IIIA). Over the 5-year follow-up there were 50 women diagnosed with a recurrence and 39 with a new primary. Over 7-years of follow-up, there were 160 deaths; 97 due to BC. In Cox proportional-hazards analysis, carriers of variant alleles of MTHFR polymorphisms, C677T (HR = 0.76, 95% confidence interval [CI]: 0.51, 1.14) and A1298C (HR = 0.66, 95% CI: 0.44, 1.00), had reduced mortality rates, adjusting for ER status and stage. In women with more severe disease who received chemotherapy, the HR was 5.6(95% CI: 2.8-10.9) for those without the T allele, and 4.3(95% CI: 2.1-9.1) for those with it present (p = 0.09) compared to those without the T allele and no chemotherapy treatment (Table 1). No interaction with chemotherapy was observed for A1298C. C677T may modify the association of chemotherapy in predicting BC survival. There is strong linkage disequilibrium between C677T and A1298C (Lewontin's D’ = 0.94) suggesting two different inheritance patterns; however, recombination between them is documented to be rare. These results should be explored further in clinical populations. Study of interactions with other genes in the folate metabolism pathway (BHMT, TS, MTR, MTRR, SHMT) with BC survival is under investigation

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2750. doi:10.1158/1538-7445.AM2011-2750
Abstract 2767: Genetic variation in obesity-related genes ADBR2, ADBR3, GHRL, HSD11B1, and SHC1 and risk of prostate cancer: A VA case-control study
Authors: Masko Elizabeth M. , Moreira Daniel M. , Banez Lionel L. , Hoyo Cathrine , Grant Delores J. , Calloway Elizabeth E. , Shuler Kathleen H. , Newman Kathryn A. , Gaines Alexis R. , Taylor Loretta A. , Robertson Cary N. , Freedland Stephen J.
Published: June 2012

INTRODUCTION: Single nucleotide polymorphisms (SNPs) are single nucleotide variations that occur within alleles among individuals. It is believed that SNPs may predispose a person to diseases such as obesity or cancer. One study showed that SNPs within genes linked with obesity were also associated with breast cancer risk. As prostate cancer (PC) mortality is linked with obesity, we determined if SNPs within 5 obesity-related genes were also linked to PC risk in a similar manner to the breast cancer study.

METHODS: A total of 53 SNPs were tagged in the genes ADBR2, ADBR3, GHRL, HSD11B1, and SHC1 using the program HAPMAP. DNA collected from 216 subjects (108 incident cases, 108 “healthy” controls) from the Durham VA Hospital were then genotyped for these SNPs. Cases and controls were frequency matched on age and BMI. Logistic regression models were used to determine the risk of obesity (BMI >30 kg/m2) and PC (and high-grade defined as Gleason >7 vs. low-grade/control) for each SNP, adjusting for age and race.

RESULTS: In our study population, 83 men were Caucasian and 133 African American. There was no significant differences in age (p=0.18), race (p=0.96), and BMI (p=0.12) for cases and controls. Among the 53 SNPs genotyped, 5 SNPs in ADRB2, ADRB3, and SHC1 were associated with an increased risk of PC (OR 1.88-2.21; p=0.01-0.04), particularly high-grade disease (OR 2.50-3.26; p=0.0004-0.05). Another 4 SNPs in ADRB2 and HSD11B1 were associated with a decreased risk of PC (p=0.01-0.05). A total of 7 SNPs were associated with an increased risk of obesity (p=0.004-0.02).

CONCLUSION: In this small pilot study, we found 14 of the 53 analyzed single SNPs in genes previously linked with obesity that were associated with PC risk, both positively and negatively at an alpha of <0.05. This is more than the 3 SNPs that would be predicted based upon random chance. Future studies will validate these results in an independent cohort, with the hope of further confirming SNPs that may be used for personalized medicine as well as providing a genetic link between obesity and PC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2767. doi:10.1158/1538-7445.AM2011-2767
Abstract 2776: Prostate cancer and dietary calcium: Effect modification by the vitamin D receptor Cdx-2 polymorphism in the California Collaborative Prostate Cancer Study
Authors: Rowland Glovioell W. , Ingles Sue A.
Published: June 2012

Background: Calcium is classified as a probable cause of prostate cancer by the World Cancer Research Fund. We previously showed that the relationship between dietary calcium intake and prostate cancer risk was modified by a the vitamin D receptor, Cdx-2 polymorphism among African Americans. The high absorption A allele increases calcium absorption and is common among African Americans. The A alleles is less common among Caucasians, who have a lower incidence of prostate cancer compared to African Americans.

Methods: We examined Caucasian and African American prostate cancer cases and controls from the California Collaborative Prostate Cancer Study. Of 1854 cases, 1140 were advanced stage at diagnosis and 714 were localized; 500 were African American and 1354 were Caucasian. Dietary calcium was assessed from a 74-item modified Block food frequency questionnaire. The VDR Cdx-2 genotype was measured by TaqMan assay. Main effects of genotype and of dietary calcium, and diet-gene interactions were estimated using conditional logistic regression, adjusting for study site (Northern/Southern California), Hispanic ancestry, socio-economic status, age, and family history of prostate cancer.

Results: Analysis of race-specific quartiles of calcium intake showed that intake of more than 680 mg/day (above the median for African Americans or above the first quartile for whites) was associated with increased prostate cancer risk (odds ratio 1.48, 95% confidence interval 1.25 – 1.77). The effect of calcium intake on risk of advanced (but not localized) prostate cancer was modified by the VDR Cdx-2 genotype for both African Americans and whites. High calcium intake (>680 mg/day) was significantly associated with increased risk only among those with the VDR Cdx-2 GG low calcium absorption genotype (OR=1.90, 95% CI 1.40 – 2.57). High absorption genotypes (GA and AA) were associated with increased risk only among those consuming less than 680 mg/day of calcium. Odds ratios were 1.24 (95% CI: 0.82 – 1.87) for genotype GA and 1.69 (95% CI: 1.05 – 2.74) for genotype AA compared to genotype GG.

Conclusions: Our findings suggest that genetically-determined high calcium absorption among African Americans could contribute to racial ethnic disparities in prostate cancer incidence.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2776. doi:10.1158/1538-7445.AM2011-2776
Abstract 2796: Suppressive effect of DNA hypomethylation on gastric carcinogenesis
Authors: Tomita Hiroyuki , Hirata Akihiro , Yamada Yasuhiro , Hara Akira
Published: June 2012

Global DNA hypomethylation and concomitant site-specific gene hypermethylation are among the most common molecular alterations in human neoplasia. Although site-specific DNA hypermethylation has been shown to be associated with the development of various tumors accompanied by transcriptional silencing of target genes, the functional significance of global DNA hypomethylation in tumorigenesis remains unclear. Previous studies have revealed that a genetic reduction of the DNA methylation levels leads to opposing effects on tumor development, depending on the tumor cell type and the stage of tumorigenesis. In the present study, we investigated the effect of DNA hypomethylation on gastric carcinogenesis in mice. DNA methyltransferase 1 (Dnmt1) hypomorphic mice, which showed that Dnmt1 hypomorphic alleles induced global DNA hypomethylation in the gastric mucosa, were used in this study. The genetic reduction of DNA methylation levels suppressed the incidence, number and size of gastric tumors in two different mouse models for gastric tumorigenesis: the N-methyl-N-nitrosourea (MNU)-induced model and the Apc (Min/+) mouse model that spontaneously develops gastric tumors with aging. Histological analyses revealed DNA hypomethylation to completely inhibit the development of invasive gastric tumors. In the MNU model, DNA hypomethylation reduced the persistent increase in the cell proliferative activity in the non-cancerous gastric mucosa exposed to MNU. However, the aberrant site-specific methylations were not found in MNU-induced mouse gastric tumors unlike in the case of human gastric tumors, thus indicating that the pattern of the site-specific aberrant methylations in mouse gastric tumors is distinctly different from that in human gastric cancers. Taken together, these findings indicate that the reduction of DNA methylation levels suppresses gastric carcinogenesis and suggest that DNA methylation is closely associated with gastric tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2796. doi:10.1158/1538-7445.AM2011-2796
Abstract 2802: Evaluation of metabolic changes induced by loss of extracellular matrix attachment using 13C Flux analysis
Authors: Grassian Alexandra R. , Metallo Christian M. , Stephanopoulos Gregory , Brugge Joan S.
Published: June 2012

Recent studies from our laboratory revealed the importance of extracellular matrix in regulating cellular metabolism. Briefly, detachment of mammary epithelial cells from extracellular matrix (ECM) causes a significant reduction in ATP levels due to reduced glucose uptake. ErbB2 overexpression restores ATP levels by maintaining glucose uptake in ECM detached cells. The loss of glucose uptake also increases ROS levels, and unexpectedly, antioxidants rescue the metabolic defect, by relieving an ROS-mediated inhibition of ATP generation by fatty acid oxidation.

These findings suggest that ECM contact is an important regulator of cellular metabolism, and that tumor cells may be able to circumvent the requirement for ECM-attachment via overexpression of certain oncogenes. We used 13C metabolic flux analysis to more thoroughly investigate the metabolic changes induced by ECM detachment and ErbB2 overexpression in the immortalized, non-transformed human mammary epithelial cell-line, MCF10A. Our results show that matrix-detachment leads to a dramatic decrease in nutrient uptake, including glucose, glutamine and pyruvate. Interestingly, we found that there is a substantial decrease in glucose flux to the tricarboxylic acid (TCA) cycle; this is due both to the decreased glucose uptake, as well as an increased diversion of glucose towards lactate production (aerobic glycolysis). ErbB2 overexpression partially reverses these defects in the ECM-detached cells. Glucose entrance to the TCA cycle is regulated by pyruvate dehydrogenase (PDH), which are in turn negatively regulated by PDH kinases (PDK1-4). Interesting, we find a dramatic increase in PDK4 levels in ECM-detached cells, which is partially prevented by ErbB2 overexpression. While PI3K signaling has previously been shown to negatively regulate PDK4 expression, we find that Mek, but not PI3K, regulates PDK4 levels in our system. Ongoing studies will further examine the regulation of glucose and pyruvate metabolism by ErbB2 and ECM. These analyses will allow us to identify unpredictable nodes of metabolic regulation by ErbB2 and ECM and may provide rational treatment approaches for targeting tumor metabolism.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2802. doi:10.1158/1538-7445.AM2011-2802
Abstract 2815: Urine TMPRSS2:ERG for prostate cancer risk stratification in men with elevated serum PSA
Authors: Tomlins Scott A. , Aubin Sheila , Siddiqui Javed , Lonigro Robert , Sefton-Miller Laurie , Miick Siobhan , Williamsen Sarah , Hodge Petrea , Meinke Jessica , Blase Amy , Penabella Yvonne , Day John , Rhodes Daniel R. , Sakamoto Kyoko , Silberstein Jonathan , Fradet Yves , Amberson James B. , Meyers Stephanie , Rittenhouse Harry , Wei John T. , Groskopf Jack , Chinnaiyan Arul M.
Published: June 2012

Background: Over 1,000,000 men undergo prostate biopsy each year in the U.S., most for “elevated” serum PSA. Given the lack of sensitivity and specificity, and unclear mortality benefit of PSA testing, methods to individualize management of elevated PSA are needed. We evaluated urine expression of TMPRSS2:ERG, a gene fusion occurring in 50% of prostate cancers, for risk-stratifying men presenting for biopsy.

Methods: TMPRSS2:ERG was measured by a clinical grade, transcription-mediated-amplification assay in prospectively collected whole-urine from 1,094 men undergoing biopsy at 10 academic and community clinics.

Findings: Urine TMPRSS2:ERG was associated with indicators of clinically significant cancer at biopsy and prostatectomy, including tumor size, high prostatectomy Gleason score and upgrading at prostatectomy. TMPRSS2:ERG in combination with urine PCA3, improved the multivariate PCPT risk calculator performance for predicting cancer on biopsy (AUC in test set, 0.79 vs. 0.64, p<0.001). Using a three-class stratification, men in the highest and lowest TMPRSS2:ERG+PCA3 score groups had markedly different rates of cancer (69% vs. 21%, p<0.001), clinically significant cancer by Epstein criteria (61% vs. 15%, p<0.001) and high grade cancer (40% vs. 7%, p<0.001) on biopsy.

Interpretation: Urine TMPRSS2:ERG, in combination with urine PCA3, enhances the utility of serum PSA for predicting prostate cancer and clinically relevant cancer on biopsy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2815. doi:10.1158/1538-7445.AM2011-2815
Abstract 282: PAI-2 promotes astrocyte differentiation from glial precursor cells via enhancing STAT3 signaling
Authors: Li Zaibo , Proschel Chris , Noble Mark
Published: June 2012

Regulation of the generation of astrocytes and oligodendrocytes is a key process in the development of normal central nervous system (CNS) and glial tumors including oligodendrocytoma, astrocytoma and glioblastoma. Glial cell differentiation occurs in two sequentially generated glial progenitor cells, the glial-restricted precursor (GRP) cells and the oligodendrocyte-type-2 astrocyte (O-2A) progenitor cells. The molecular mechanisms of cell generation in these precursor cells are only incompletely understood.

In this study, PAI-2 (Plasminogen Activator inhibitor-2) was identified to be upregulated during glial cell differentiation. Ectopic expression of PAI-2 induced GRP cells to differentiate into astrocytes and inhibited their proliferation. In contrast, suppression of endogenous PAI-2 by small interfering RNA in GRP cells promoted cell proliferation and inhibited their ability to differentiate into astrocytes. More interestingly, we observed a higher Rb protein level and a correlated lower E2F1 transcriptional activity during glial differentiation due to increased PAI-2 protein level. In consistent with these findings, ectopic expression of PAI-2 indeed stabilized Rb protein.

We also found that PAI-2 upregulated GFAP expression in glial progenitor cells, an antigenic marker for astrocytes. Astrocytogenesis is controlled by two different signaling, the IL-6, LIF or CNTF-induced STAT3 pathway and the BMP-4-induced SMAD1 pathway. Interestingly, PAI-2 significantly enhanced CNTF, LIF or IL-6-induced GFAP expression as illustrated by both reporter assay and immunostaining, but not BMP4-induced GFAP expression. Furthermore, We demonstrated that PAI-2 could enhance CNTF-induced STAT3 phosphorylation and the complex formation between STAT3 and p300. It has also been reported that Rb could enhance the transcriptional activity of several transcription factors via enhancing p300/CBP activity by releasing them from some inhibitory transcriptional repressors such as EID1 (E1A-like inhibitor of differentiation). Indeed, suppression of Rb by small interfering RNA or overexpression of EID1 abrogated PAI-2's effect on STAT3 activity. Also, suppression of endogenous EID1 by small interfering RNA could further enhance PAI-2's effect. Finally, we illustrated Glial precursor cells from PAI-2 knockout mice are less responsive to CNTF and IL-6 than wild-type cells. Based on these data, we concluded that PAI-2 promotes glial progenitor cells to differentiate into astrocytes via stabilizing Rb, which can abrogate EID's inhibitory effect, and then enhancing STAT3 transcriptional activity induced by CNTF or IL-6.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 282. doi:10.1158/1538-7445.AM2011-282
Abstract 2844: Systems biology analysis of tumor and stromal genes in different metastatic microenvironments
Authors: Sevenich Lisa , Mason Steve , Rapaport Franck , Massague Joan , Leslie Christina , Joyce Johanna
Published: June 2012

Metastasis is a multistage process that requires cancer cells to escape from the primary tumor, survive in the circulation, seed at distant sites and colonize these foreign tissue environments. Each of these processes involves rate-limiting steps that are influenced by stromal cells of the tumor microenvironment.

Our goal is to dissect organ-site specific signatures of tumor-stroma interactions in metastasis. In this approach we devised an experimental and computational strategy to enable the simultaneous analysis of tumor and stromal genes in lesions from three distinct metastatic microenvironments. We took advantage of a recently developed system where organ-site specific metastatic variants were selected in vivo from a parental breast cancer cell line and home to the brain, the bone and the lung in xenografted animals. An important technological advance is the HuMu ProtIn (Protease/Inhibitor) array that was designed to distinguish between human (Hu) and mouse (Mu) gene expression. By using the HuMu ProtIn array we can determine whether differentially expressed proteases and endogenous protease inhibitors are of tumor (human) or stromal (mouse) origin. This allowed us to simultaneously capture the tumor and stromal contributions in intact tumors.

After profiling of brain, bone and lung metastases at different stages of development we employed knock-down and knock-out strategies to experimentally validate the biological relevance of predicted candidate genes including the serine protease Htra1 and the cysteine protease cathepsin S. Cathepsin S represents an interesting example as the expression of tumor-derived cathepsin S decreases during the progression from early to late brain metastasis, whereas the expression of stromal-derived cathepsin S increases over time. Targeting either tumor- or stromal derived cathepsin S did not significantly prolong tumor-free survival, however the combined ablation of tumor- and stromal derived cathepsin S resulted in a dramatic impairment of brain metastasis formation.

This study emphasizes the need for a better understanding of the complex reciprocal interactions between tumor cells and stromal cells with the ultimate goal to improve the predictive value of prognostic evaluation and to develop combination therapies that target the tumor along with its microenvironment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2844. doi:10.1158/1538-7445.AM2011-2844
Abstract 2861: The C/EBPbeta isoform, liver-inhibitory protein (LIP), induces autophagy in breast cancer cell lines
Authors: Abreu Maria M. , Sealy Linda
Published: June 2012

Autophagy is an evolutionarily conserved cellular process involving the bulk degradation of cellular components in the cytoplasm via the lysosomal degradation pathway. Autophagy manifests a protective role in stressful conditions such as nutrient or growth factor depletion; however, extensive degradation of regulatory molecules or organelles essential for survival can lead to the demise of the cell, or autophagy-mediated cell death. The role of autophagy in cancer is controversial with roles in both tumor suppression and tumor promotion proposed.

Here we report that an isoform of the C/EBPbeta transcription factor, liver-enriched inhibitory protein (LIP), stimulates autophagy and induces cell death in human breast cancer cells. LIP overexpression is incompatible with cell growth and when cell cycle analysis was performed, a DNA profile of cells undergoing apoptosis was not observed. Instead, LIP expressing cells appeared to have large autophagic vesicles when examined via electron microscopy. Autophagy was further assessed in LIP expressing cells by monitoring the development of acidic vesicular organelles and conversion of LC3 from the cytoplasmic form to the membrane-bound form. Our work shows that C/EBPbeta isoform, LIP, is another member of the group of transcription factors, including E2F1 and p53, which are capable of playing a role in autophagy. Knowledge of the mechanisms controlling autophagy and identifying new agents capable of inducing cell death has vast potential to improve cancer therapeutics by enabling effective induction of an alternative death pathway, especially in, but not limited to, tumor cells that are resistant to apoptosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2861. doi:10.1158/1538-7445.AM2011-2861
Abstract 2892: Glycogen synthase kinase-3α regulates cell proliferation in pancreatic cancer cells by regulating constitutive TAK1 and NF-κB signaling
Authors: Bang Deepali , Wilson Willie , Yeh Jen Jen , Baldwin Albert S.
Published: June 2012

Pancreatic ductal adenocarinoma (PDA) represents the fourth leading cause of cancer-related deaths in the United States with a 5-year patient survival rate less than 5%. The transcription factor NF-κB is constitutively active and contributes to cell survival and cancer therapy resistance in these tumors. Previous reports have linked constitutive IκB kinase (IKK) activity to canonical NF-κB signaling in human pancreatic cancer cells. However, the signaling events that drive IKK activity remain poorly understood. TGF-β activated kinase 1 (TAK1) is an established regulator of IKK activity and has been shown to be active in human cancer cell lines. Moreover, we previously reported that glycogen synthase kinase-3 (GSK-3) signals through IκB kinase (IKK) to facilitate downstream pro-survival NF-κB signaling and inhibition of GSK-3 suppressed cell proliferation in pancreatic cancer cells. Here, we investigate the status of TAK1 activity in pancreatic cancer cells and explore the potential regulation of constitutive TAK1-IKK signaling by GSK-3.

We observed elevated levels of TAK1 phosphorylation and its association with TAB1 in a panel of pancreatic cancer cell lines. Genetic ablation of TAK1 in Panc-1 and MiaPaCa-2 cell lines resulted in decreased pro-survival NF-κB signaling. TAK1 was found to interact with GSK-3α in co-immunoprecipitation studies and both the genetic ablation and inhibition of GSK-3α suppressed NF-κB activity, TAK1 levels and growth of pancreatic cancer cells. We also observed reduction in the levels of TAB1 and TAB2, binding partners of TAK1, upon pharmacological inhibition of GSK-3. Additionally, pharmacological inhibition of GSK-3 significantly suppressed the levels of TAK1 and the growth of human pancreatic tumor explants in mice. Recently non-canonical or IKK- independent NF-κB signaling was also observed to be constitutively active and contributing to cell survival in pancreatic cancer cells. Preliminary data from si-RNA mediated knockdown studies suggests a positive regulation of non-canonical NF-κB signaling by GSK-3α. Overall, our data suggests that constitutive TAK1/TAB1-IKK and non-canonical NF-κB signaling in pancreatic cancer is driven by novel GSK-3α dependent mechanisms. These data provide new insight into our understanding of constitutive NF-κB regulation in pancreatic cancer and presents TAK1 as a potential new therapeutic target for this disease. Further investigation is required to understand the mechanism of GSK-3α-TAK1/TAB1 and GSK-3α-non canonical NF-κB regulation and their effect on pro-survival NF-κB signaling in pancreatic cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2892. doi:10.1158/1538-7445.AM2011-2892
Abstract 2928: Regulation of MST1 and MST2 by mTOR and androgen receptor signaling in prostate cancer
Authors: Collak Filiz Kisaayak , Luthringer Daniel , Kim Hyung L. , Chung Leland , Cinar Bekir
Published: June 2012

The serine/threonine kinases MST1 and MST2 (hippo in Drosophila) were originally identified as pro-apoptotic proteins. In addition to their pro-apoptotic functions, evidence suggests that deficiency in MST1 and MST2 and their downstream effectors has been linked to developmental defects, tissue overgrowth, and cancer, including prostate cancer (PCa). However, the molecular mechanism that may modulate MST1 or MST2 signaling in PCa cells remains unknown. Here we investigate the impact of androgen receptor (AR) and PI3K-AKT-mTOR signaling on MST1 or MST2. We used biochemical, mutagenesis, histochemical, and pharmacological approaches to carry out this investigation. First, we demonstrate that AR and MST1 co-localize and form protein complexes in cell nuclei. Androgen further stimulates the interaction between the two proteins and reduces MST1 kinase activity in LNCaP PCa cells, suggesting that AR may sequester MST1 in an inactive form. Second, we showed that MST1 at Threonine120 (T120) was exclusively phosphorylated in cell nuclei, whereas MST2 at Threonine117 (T117), corresponding to MST1-T120, was phosphorylated only in the cytoplasm, although MST1 and MST2 were found in both locations. Similar phosphorylation patterns were also observed in prostate cancer tissue samples. Third, we have found that the T120 is not a physiologic target of AKT kinase in vivo, because the inhibition of AKT activity by a specific PI3K inhibitor, LY294002, had no effect on the phosphorylation of MST1 at the T120 site, but it did inhibit MST1-T117 phosphorylation. Furthermore, attenuation of mTOR activity by Ku0063794, a specific mTOR1 and mTOR2 inhibitor, abolished MST2-T117 phosphorylation, but without having an effect on the levels of phospho-MST1-Thr120. Lastly, the use of combined LY294002 and Ku0063794 compounds synergistically inhibited PCa cell growth, relative to a single compound. Our data suggest that AR and mTOR pathway signaling may oppose MST1 and MST2 in discrete cell locations. Thus, understanding the functional relationship between these signal networks in the context of cell proliferation and cell death may have important therapeutic implications in prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2928. doi:10.1158/1538-7445.AM2011-2928
Abstract 2933: Inhibition of MAPK signaling prevents Fra-1-mediated CD44 expression in human brain tumor cells
Authors: Beasley Selina A. , Raines Timothy A. , Martin Patrick M.
Published: June 2012

Glioblastoma multiforme (GBM) is a grade IV brain tumor that exhibits a high growth rate and the capacity to invade surrounding tissue. The invasive capacity displayed by GBM cells is a major reason patients diagnosed with GBMs have poor prognosis. Currently, there are few effective treatment options for GBM. The invasive capacity of GBM cells has been associated with CD44, a transmsmbrane glycoprotein. CD44 is a cell surface receptor for hyaluronic acid (HA) which is a major component of the extracellular matrix that comprises the brain. Recent studies demonstrate that CD44 expression has been associated with fos related antigen 1 (Fra-1) an AP-1 transcription factor in GBM. Specifically, our lab has shown that reducing Fra-1 protein levels with siRNA results in decreased amounts of CD44 protein. To better understand Fra-1 regulation of CD44 we examined the signaling mechanisms that mediate Fra-1-regulated CD44 expression. Several human GBM cell lines (U-251 MG, U-1242 MG, and A-172) were treated with epidermal growth factor (EGF 20ng/ml) at various time points to determine the role of EGF stimulation on Fra-1 and CD44 protein expression. In addition to EGF cells were treated with inhibitors to four known signaling pathways: PI3 kinase (LY 294002, 20µM); mTOR (rapamycin, 25nM); Jun kinase (SB203580, 20 µM); and MAP kinase (U-0126, 20µM) to determine whether these pathways mediate Fra-1-regulated CD44 expression. Western blot analysis was used to determine the level of protein expression of Fra-1 and CD44 following inhibitor treatment. Inhibition of the MAPK pathway demonstrated a significant decrease in Fra-1 and CD44 protein levels while inhibition of the AKT and mTOR signaling pathways respectively, exhibit less regulation of Fra-1 and CD44 levels. In addition to determining the regulation of Fra-1 and CD44 protein expression we also assayed the mRNA levels of Fra-1 and CD44 following inhibitor treatment. Fra-1 and CD44 mRNA levels decreased following U-0126 treatment, correlating the decrease of mRNA levels with the decrease of protein expression described previously. Taken together these data suggest that the MAP kinase pathway is responsible for regulating Fra-1-mediated CD44 mRNA and protein expression in malignant brain tumor cell lines.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2933. doi:10.1158/1538-7445.AM2011-2933
Abstract 296: Characterization of prostate cancer circulating tumor cells using E-selectin coated-microtubes
Authors: Gakhar Gunjan , Geng Yue , Jodari-Karimi Mona , Tagawa Scott , Bander Neil , King Michael , Nanus David
Published: June 2012

Background: Metastasis and invasion is facilitated by adhesion of circulating tumor cells (CTCs) to endothelial cells in the blood vessel. Initial recruitment of CTCs to the blood vessel endothelium is mediated through selectin proteins. We used microtube coated with selectin proteins to simulate CTC adhesion under flow, to elucidate the complex physicochemical dynamics that control CTC adhesion in the bloodstream.

Methods: Sterilized microrenathane microtubes were functionalized by E-selectin +/- anti-PSMA (mAb J591) and anti-EpCAM antibodies. Functionalized microtubes were used to observe the rolling behavior of prostate cancer cell lines MDAPCa2b, LNCaP C4-2, and PC-3. MDAPCa2b cells alone or mixed with normal peripheral blood mononuclear cells (PBMCs) were incubated with fluorescently conjugated mAbJ591, and the mixture flowed through the microtube for identification and capture efficiency. PBMCs isolated from prostate cancer patient's blood were similarly processed.

Results: MDAPCa2b cells showed robust rolling at 1 dyne/cm2 shear stress while LNCaP, C4-2, and PC-3 cells did not exhibit rolling behavior on E-selectin coated microtubes. 7.5 cells were observed rolling at 1 dyne/cm2 compared to 1.5 cells at 8 dyne/cm2 per 100 mm2 area. To determine if prostate cancer cells could be identified in a mixture of PBMCs, MDAPCa2b cells were spiked in PBMCs and labeled with fluorescently conjugated mAb J591. MDAPCa2b cells demonstrated selective fluorescence which did not alter their rolling behavior. A 50% capture efficiency of MDAPCa2b cells spiked in PBMCs was achieved when flowed through E-selectin and anti-PSMA coated microtube. After establishing rolling and selective fluorescence in prostate cancer cell line, we used prostate cancer patient's blood. CTCs in prostate cancer patient's blood showed rolling behavior on E-selectin coated microtube. Further, these CTCs were PSMA-positive after incubation with fluorescently conjugated mAbJ591 and easily identified during the flow through the microtube.

Conclusion: Our data shows that CTCs in prostate cancer patients exhibit rolling behavior, which may facilitate invasion and metastasis. Further, selective ex vivo labeling of CTCs enables rapid identification for subsequent characterization of their adhesion and invasive phenotype.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 296. doi:10.1158/1538-7445.AM2011-296
Abstract 2990: Characterization of a mitotic interaction of ATM with AuroraB
Authors: Danforth Rebecca L. , Tang Xi , Yang Chunying , Xu Bo
Published: June 2012

Ataxia-telangiectasia mutated (ATM) is a protein kinase that plays a pivotal role in DNA damage-induced cell cycle checkpoints and DNA repair. Mutation of ATM leads to the autosomal recessive disorder ataxia-telangiectasia, characterized by comprehensive clinical phenotypes such as cancer predisposition and neurodegeneration. One of the cellular phenotypes of ATM-deficiency is the spindle assembly checkpoint (SAC) defect and aneuploidy, indicating that ATM has a functional role in mitosis. We have recently demonstrated that ATM is activated in mitosis and that ATM is required for SAC. The molecular mechanism of mitotic ATM activation has started to emerge. We show here using coimmunoprecipitation that ATM interacts with Aurora B in unsynchronized cells and that this interaction increases during mitosis. Aurora B is a protein kinase and mitotic chromosomal passenger involved in the progression of mitosis. Although regulation of the Aurora B activity in response to DNA damage is dependent on ATM, Aurora B appears to serve as an upstream element of the mitotic ATM activation pathway. Aurora B phosphorylates ATM at Ser1403 and this phosphorylation event is required for activation of the SAC. We also show that Ser1403 is dephosphorylated by Protein Phosphatase 1 (PP1), thus implicating PP1 in the regulation of mitosis and the SAC. We demonstrate that the interaction between ATM and Aurora B is partially dependent on the enzymatic activity of both proteins. We also characterize the protein domains essential for the interaction of ATM with Aurora B and study the functional significance of this interaction. These data expand to our understanding of the roles of ATM outside of DNA damage repair and link ATM to cell cycle control.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2990. doi:10.1158/1538-7445.AM2011-2990
Abstract 3024: Methylation analysis of the VDR gene in ovarian normal and tumorous tissue
Authors: Poulin Matthew , Meyer Ann , Bartley Andrew , Guo Qin , Xu Jessica , Yan Liying
Published: June 2012

Ovarian cancer remains the most lethal gynaecological cancer. Various molecular changes have been identified and have shown promise for their diagnostic, prognostic and curative capacity but still need further validation. Vitamin D has been shown to play a role in the suppression of tumor growth and in the modification of some properties of fully transformed malignant cells. In light of evidence for promoter methylation of the vitamin D receptor in the control of the expression of this gene, we have designed methylation assays that cover many regions of this gene in order to determine its methylation profile in normal individuals, ovarian tumors and ovarian cell lines. This gene is highly polymorphic and SNP assays were also designed to analyze the genetic variability within the VDR gene as well. In order to determine if the methylation state and/or the genetic make-up within the VDR gene plays a role in ovarian cancer we analyzed 76 CpG sites and 20 SNPs in normal male blood DNA and tumor sample DNA. We determined the base-line methylation and genetic state in a non-cancerous sample and found that the promoter region from -700 from the transcriptional start site, through the 5’UTR and into intron 1 shows very low or no methylation. Conversely the CpG sites at the intron 10/Exon 11 boundaries were very highly methylated in normal blood DNA. We examined these same regions in 10 sets of ovarian tumors and their corresponding normal surrounding tissue. There is a small increase in methylation around -700 region in the tumor tissue compared to the normal blood DNA. Some cell line showed higher levels of methylation as well. COV318 has an elevated level of methylation and so has SKOV, OB58, and OV17r. There was no significant difference, however, between tumor/normal samples starting from -500 into intron 1. The methylation level in these samples is all very low. Within the intron 10/exon 11 region, a majority of the tumors show slightly higher levels of methylation than the normal tissue. The T>C SNP rs731236 at the intron 10/exon 11 boundary is within a CpG site that gives an interesting methylation profile between some of the samples that will be presented.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3024. doi:10.1158/1538-7445.AM2011-3024