bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1745: Pomegranate sensitizes tamoxifen action in breast cancer cells: A novel therapeutic strategy
Authors: Banerjee Shreya , Haque Inamul , Kambhampati Suman , Banerjee Sushanta K.
Published: July 2012

It is estimated that in year 2009 over 1 million women worldwide will be diagnosed with breast cancer. Roughly, 70% of breast cancer will be estrogen receptor-alpha (ER-α) positive, which facilitates their growth in the presence of estrogen. The presence of ER-α is able to determine if tumors will respond to the estrogen-blocking/ER-antagonist drug Tamoxifen (TAM). However, a significant fraction (∼40%) of ER-positive tumors is minimally or completely unable to respond to TAM. However, it is unclear why some breast cancer cells resist TAM and how to make these cells respond. Early evidence suggests Pomegranate fruit extracts (PFEs) exhibit an anticancer effect against some cancers. The hypothesis of the study was that PFEs may able to enhance TAM's effect in ER-positive MCF-7 breast cancer cells. To test the hypothesis, we determined the effect of PFEs on sensitive and TAM-resistant-MCF-7 cell viability and cell death (apoptosis) in the presence or absence of TAM under estrogenic or non-estrogenic culture environment. Cell viability was determined by cell counting using Trypan-blue assay and cell cycle distribution. Apoptosis was determined by Annexin-V-apoptotic-detection assay and immuno-Western blotting of apoptosis-related-genes (i.e., BCl-2 and Bax). The present studies demonstrated that PFEs enhance the TAM action in both sensitive and TAM-resistant MCF-7 cells through the inhibition of cell viability (regular or estrogen-induced) by inducing cell-death machinery. Collectively, the results showed for the first time that pomegranate combined with TAM may represent a novel and powerful approach to enhance TAM action.

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 1745. doi:10.1158/1538-7445.AM2011-1745
Abstract 1746: Modulation of ABCG2 mediated multidrug resistance by xanthine derivatives
Authors: Ding Rui , Shi Jia , Scotto Kathleen W.
Published: July 2012

ABCG2 is an ATP-binding-cassette (ABC) transporter that confers multidrug resistance (MDR) in tumor cells by extruding a broad variety of chemotherapeutic agents, ultimately leading to failure of cancer therapy. Accordingly, the downregulation of ABCG2 expression and/or function has been proposed as part of a regimen to improve cancer therapeutic efficacy. Adenosine receptors (ARs), belong to the G-protein coupled receptor superfamily, and play important roles in stimulating neuronal cells, regulating cell proliferation and controlling immune responses. Adenosine receptor antagonists, a large collection of small molecules mainly composed of methylxanthines and other xanthine derivatives, have been used or implicated in many therapeutic applications, such as treatment of asthma, chronic bronchitis, emphysema and neural degenerative diseases. Previously, we have shown that the non-selective AR antagonist 1,3,7-methyxanthine (caffeine) can dramatically downregulate ABCG2 expression levels in cancer cell lines, increasing the intracellular retention of the ABCG2 specific substrate Mitoxantrone (MX) and markedly sensitizing cells to this chemotherapeutic agent. In order to find more potent and specific modulators of ABCG2 expression, we recently tested other ARs antagonists. Among the compounds we have examined, the non-selective antagonists theophylline, theobromine, paraxanthine, and the A2R selective antagonists 8-(3-chlorostyryl), caffeine (CSC) and 3,7-dimethyl-1-propargylxanthine (DMPX), were capable of downregulating ABCG2 protein levels to varying degrees. An A1R selective antagonist, 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX), currently in clinical trials, also decreased the expression of ABCG2 significantly at physiologically- relevant concentrations. In addition, the natural ligand of the ARs, adenosine, completely blocked the downregulation of ABCG2 by caffeine, suggesting that adenosine receptors and their downstream signaling pathways are involved in the regulation of ABCG2 gene expression. These findings suggest that xanthine adenosine receptor antagonists could be developed as combination therapy to improve the efficacy of drugs that are ABCG2 substrates.

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 1746. doi:10.1158/1538-7445.AM2011-1746
Abstract 1749: Role of eIF3a in DNA repair and lung cancer chemo sensitivity
Authors: Yin Jiye , Dong Zizheng , Liu Zhaoqian , Zhang Jianting
Published: July 2012

Drug resistance is one of the major obstacles in successful chemotherapy of lung cancers. However, the mechanism of resistance is not yet clearly understood. Recently, eIF3a that plays an important role in translational control and regulation of gene expression was found to correlate negatively with prognosis in human cervical and esophageal cancers. We, thus, hypothesize that eIF3a may be an important factor in lung cancer response to chemotherapy by regulating the expression DNA repair proteins. Examination of 211 lung cancer tissue samples revealed that eIF3a expression negatively correlates with responses of the patients to cisplatin treatment. Ectopic over-expression or knockdown of eIF3a reduced or increased cellular resistance, respectively, to cisplatin, doxorubicine, and etoposide (VP-16) in cell lines as determined using MTT assay. Altering eIF3a expression also changed DNA repair activity as well as the expression of DNA repair proteins. We conclude that eIF3a possibly suppresses the synthesis of DNA repair proteins via translational control, which in turn contributes to the increased sensitivity to DNA-damaging anticancer drugs.

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 1749. doi:10.1158/1538-7445.AM2011-1749
Abstract 1888: HPV viral load and alcohol synergize to increase the risk of cervical intraepithelial neoplasia (CIN)1 in HPV positive women: Korean HPV Cohort Study
Authors: Kim Mi Kyung , Lee Sang Hoon , Min Kyung-Jin , Lee Jae Kwan
Published: July 2012

Purpose: To investigate the associations between alcohol and the risk of cervical intraepithelial neoplasia (CIN) and cervical cancer in women with high risk HPV-positive in the Korean HPV cohort study (KHPV).

Subjects and Methods: The KHPV recruited 1,243 women, aged 18-65 from March 2006 up to December 2009, including HPV-positive women with normal cytology (n=147), CIN1 (n=164), CIN2/3 (n=161) and cervical cancer (n=202). Detailed information on consumption of alcoholic beverages at baseline and on other lifestyle factors during lifetime was collected from questionnaires. Multinomial logistic analysis estimated the multivariate-adjusted odds ratio.

Results: Drinkers had an increased risk of CIN1 (OR = 2.16; 95% CI: 1.26 – 3.72) compared to nondrinkers, after adjusting for potential confounders. The amount of alcohol consumption (p for trend = 0.027), and the frequency of alcohol consumption (p for trend = 0.037) were significantly associated with the risk of CIN1. In addition, alcohol drinking had significant effects on the risk of CIN1 in the analyses adjusted for multivariables (OR=19.1, 95% CI=6.60-55.3, interaction p <0.001). The relative excess risk due to interaction was 15.7, and the attributable proportion due to the interaction and synergy index were 0.71, and 3.89, respectively. No associations were found between alcohol drinking and CIN2/3 and cervical cancer.

Conclusion: Our data showed HPV and alcohol synergize to increase the risk of CIN1 among high-risk HPV-positive women.

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 1888. doi:10.1158/1538-7445.AM2011-1888
Abstract 1889: Helicobacter pylori seropositivity and risk of lung cancer
Authors: Koshiol Jill , Flores Roberto , Lam Tram , Taylor Philip R. , Weinstein Stephanie , Virtamo Jarmo , Albanes Demetrius , Perez-Perez Guillermo , Caporaso Neil E. , Blaser Martin J.
Published: July 2012

BACKGROUND: Lung cancer is the leading cause of cancer mortality worldwide. Infections may contribute to lung carcinogenesis. Results from a few small studies have suggested that Helicobacter pylori (HP) may be a potential risk factor. However, these studies have been limited in size and in the evaluation of lung cancer histology and smoking.

METHODS: We conducted a study of 350 lung adenocarcinoma cases, 350 squamous cell carcinoma cases, and 700 controls nested within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC) cohort of male Finnish smokers. Controls were 1 to 1 matched by age (+/- 5 years) at and date (+/- 30 days) of baseline serum draw and had to be alive and cancer free at the date that the corresponding case was diagnosed. We used enzyme linked immunosorbent assays to detect immunoglobulin G antibodies against HP whole-cell and CagA antigens and calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) for associations between HP seropositivity and lung cancer risk using conditional logistic regression.

RESULTS: 79% of cases and 78% of controls were seropositive for whole cell HP, and 43% of cases and 44% of controls were seropositive for the cytotoxin-associated gene (cagA) antigen. Whole cell seropositivity was not associated with lung adenocarcinoma (OR: 1.2, 95% CI: 0.80-1.8) or squamous cell carcinoma (OR: 1.1, 95% CI: 0.73-1.6) after adjusting for age at serum draw, date of serum draw, age at smoking initiation, pack-years, and cigarettes smoked per day. Similarly, CagA seropositivity was not associated with lung adenocarcinoma (OR: 1.1, 95% CI: 0.78-1.5) or squamous cell carcinoma (OR: 0.88, 95% CI: 0.63-1.2).

CONCLUSIONS: Despite earlier small studies suggesting that HP may contribute to lung carcinogenesis, HP seropositivity does not appear to be associated with lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1889. doi:10.1158/1538-7445.AM2011-1889
Abstract 1908: Meta-analysis of prospective epidemiologic studies of red meat intake and colorectal cancer
Authors: Alexander Dominik D. , Cushing Colleen A. , Perez Vanessa , Weed Douglas L.
Published: July 2012

Background: The relationship between red meat consumption and colorectal cancer (CRC) has been the subject of scientific debate. Objective: To estimate the summary association between red meat intake and CRC and to examine sources of heterogeneity, a meta-analysis of prospective studies was conducted. Design: Thirty-four prospective studies of red meat and CRC were identified, of which, 25 represented independent non-overlapping study populations. Summary relative risk estimates (SRREs) for high vs. low intake and dose-response relationships were calculated. Results: In the high vs. low intake meta-analysis, the SRRE was 1.12 (95% CI: 1.04-1.21) with significant heterogeneity (p = 0.014). Summary associations were modified by tumor site and gender. The SRREs for colon cancer and rectal cancer were 1.11 (95% CI: 1.03-1.19) and 1.19 (95% CI: 0.97-1.46), respectively. The SRREs among men and women were 1.21 (95% CI: 1.04-1.42) and 1.01 (95% CI: 0.87-1.17), respectively. Conclusions: The available epidemiologic data are not sufficient to support an independent and unequivocal positive association between red meat intake and CRC. This conclusion is based upon summary associations that are weak in magnitude, heterogeneity across studies, inconsistent patterns of associations across the sub-group analyses, and the likely influence of confounding by other dietary and lifestyle factors.

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 1908. doi:10.1158/1538-7445.AM2011-1908
Abstract 1911: Dietary intake of riboflavin and risk of lung cancer among non-smokers: A prospective cohort study among Chinese women
Authors: Cai Qiuyin , Beeghly-Fadiel Alicia , Shrubsole Martha J. , Shu Xiao-Ou , Yang Gong , Ji Bu-Tian , Li Honglan , Chow Wong-Ho , Gao Yu-Tang , Zheng Wei
Published: July 2012

Lung cancer is the leading cause of cancer death in the United States and many other countries. A significant subset of lung cancers is not associated with smoking, and risk factors for these cancers remain unclear. Riboflavin (vitamin B2), a water-soluble vitamin, is involved in vital metabolic processes and is necessary for normal cell function, growth, and energy production. Riboflavin is the central component of the flavin mononucleotide (FMN) and flavin dinucleotide (FAD), coenzymes for a wide variety of oxidative enzymes. We prospectively examined the association of dietary intake of riboflavin with lung cancer risk in the Shanghai Women's Health Study cohort. A total of 73,237 women aged 40-70 years and free of cancer at enrollment were included in this analysis. Usual dietary intake was assessed at baseline (1997-2000) through in-person interviews by using a validated food-frequency questionnaire. We used Cox proportional hazards regression to estimate the relative risks (RR) and 95% confidence intervals (CI) for the association of lung cancer risk with dietary riboflavin consumption. In 665,554 person-years of follow-up, we identified 328 lung cancer cases, of which 303 were non-smokers. Dietary intake of riboflavin was inversely associated with lung cancer risk. The RRs (95% CI) of developing lung cancer among non-smokers decreased with increasing quintiles of riboflavin intake (P for trend = 0.007) from 1.0 to 1.01 (0.73-1.42), 0.77 (0.53-1.13), 0.81 (0.55-1.20), and 0.51 (0.31-0.83) for the lowest to highest quintiles. Exclusion of 51 cases diagnosed within two years of follow-up did not change the HR estimations appreciably. Further, adjusting for dietary intakes of other B vitamins (B1, B6, B12, niacin, and folate) and methionine did not meaningfully affect the HR estimates. No statistically significant associations were found for other B vitamins. In summary, our findings among non-smoking Chinese women suggest that dietary intake of riboflavin may reduce the risk of lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1911. doi:10.1158/1538-7445.AM2011-1911
Abstract 1914: Consumption of Lake Ontario sport fish and prostate cancer incidence in the New York State Angler Cohort Study (NYSACS)
Authors: Green Joseph W. , Mu Lina , Swanson Mya , Mix Jacqueline , Bonner Matthew R.
Published: July 2012

Fish from the Great Lakes are an important source of exposure to persistent organic pollutants, including polychlorinated biphenyls (PCBs) and organochlorine pesticides (e.g., Mirex and DDT). Some of these pollutants are hypothesized to be hormonally active and therefore may increase the risk of prostate cancer. Conversely, fish are also a source of micro- and macro-nutrients hypothesized to have chemopreventive properties. We investigated the consumption of sport-caught fish from Lake Ontario and the incidence of prostate cancer in the NYSACS, a prospective cohort of 17,110 anglers and their spouses aged 18 to 40 years old at enrollment. Participants completed a mailed self-administered questionnaire upon enrollment in 1991. Demographic factors, smoking history and selected potential confounders were ascertained. The questionnaire also queried for the number of years that fish from Lakes Ontario and Erie were consumed as well as the preparation and cooking practices for sport caught fish. As of December 31, 2008 fifty-eight first primary incident prostate cancers were identified via the New York State Cancer Registry. Vital status was determined by linkage with the Social Security Administration Death file. Of the 10,436 males enrolled at baseline, 10% (n=1,075) were lost to follow-up. Fish consumption was dichotomized into never vs. ever. Duration of consumption was categorized into tertiles based on the distribution among the cases who reported eating L Ontario sport caught fish. Poisson regression was used to calculate rate ratios (RR) and 95% confidence intervals, adjusting for age, education and pack-years of smoking. Ever eating Lake Ontario fish was inversely associated with prostate cancer incidence (RRadjusted=0.5 (95% CI=0.3-0.9)) compared with never consumers. In addition, we found a suggestion of an inverse association with increasing duration of L. Ontario fish consumption (non-eaters RR = 1.0 (ref); 1st tertile RR = 0.6 (95% CI = 0.3-1.3); 2nd tertile RR = 0.4 (95% CI = 0.2-1.0); 3rd tertile RR = 0.5 (95% CI = 0.2-1.0); although the exposure-response gradient was neither monotonic nor significant (ptrend = 0.157). The exposure-response gradients were similar when consumption was lagged 5- and 10-years (5-year lag ptrend = 0.289; 10-year ptrend = 0.269). While interpretation is complicated by a lack of information on family history of prostate cancer, and a small number of cases, these preliminary results are suggestive of an inverse association between Lake Ontario fish consumption and prostate cancer risk.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1914. doi:10.1158/1538-7445.AM2011-1914
Abstract 1918: Type 2 diabetes mellitus and colorectal neoplasia risk in Puerto Rican Hispanics: A case-control study
Authors: Diaz-Algorri Yaritza , Gonzalez Dilka , Lozada Maria E. , Hernandez Jessica , Pedrosa Carmen , Toro Doris H. , Cruz-Correa Marcia
Published: July 2012

Background: Epidemiological studies have provided inconclusive evidence regarding the potential link between type 2 diabetes mellitus (DM) and colorectal cancer (CRC).The association between type 2 DM and colorectal neoplasia (colorectal cancer and/or adenomas) has not been well studied in Hispanics, an ethnic minority at high risk for type 2 DM.

Objective: To evaluate the association between type 2 DM and colorectal neoplasia (CRN) in Puerto Rican Hispanic adults enrolled in the studies Epidemiology of Loss of Imprinting in Colorectal Cancer, Familial Colorectal Cancer Registry and the Type 2 diabetes mellitus and colorectal neoplasia risk in Hispanics: A case-control study at the VA Caribbean Healthcare System.

Methods: The case-control study included patients with incident CRN and controls with negative colonoscopy and without previous history of CRC or adenomas evaluated from January 1, 2005 to December 31, 2009. Diagnosis of type 2 DM was established by previous medical diagnosis and/or anti-diabetic medications use. Unconditional logistic regression was employed to estimate the odds ratio (OR) between type 2 DM and CRN using STATA 10.0.

Results: A total of 422 participants (mean age 60.8 ± 12.1 yrs., 61.1% males), prevalence of type 2 DM was 26.3%. 276 patients with CRN and 146 controls were evaluated. In the cases, the prevalence of colorectal adenomas was 25.4% (70/276) and the prevalence of colorectal cancer was 74.6% (206/276). Colorectal neoplasia were mostly adenocarcinomas (60.4%), located in the distal colon (37.3%), and with TNM stage III (21.4%). Cases were mostly men (p=0.01), had lower education (p<0.001) and reported lower use of aspirin (p=0.02) compared to the controls. Cases and controls did not differ by median age (p=0.52), first degree of family history of CRC (p=0.27), first degree of family history of DM (p=0.33) or obesity (p=0.73). There were no statistical significant associations between DM and CRN (OR=1.41; 95% CI: 0.74-2.68), DM and CRC (OR=1.70; 95% CI: 0.74-3.87) or DM and colorectal adenomas (OR=1.04; 95% CI: 0.45-2.42) after adjusting for gender, age, education, aspirin use, obesity and study center.

Conclusion: We did not observe a statistical significant association between type 2 DM and CRN. Nonetheless, a tendency towards an increase risk of colorectal neoplasia was observed among type 2 DM patients on adjusted analysis. Possible explanation for our lack of association may be related to high prevalence of type 2 DM in cases and controls and/or the high prevalence of obesity in the study sample.

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 1918. doi:10.1158/1538-7445.AM2011-1918
Abstract 1921: Body fatness and sex steroid hormone concentrations in US men – Results from NHANES III
Authors: Rohrmann Sabine , Shiels Meredith S. , Lopez David S. , Rifai Nader , Nelson William G. , Kanarek Norma , Guallar Eliseo , Menke Andy , Joshu Corinne E. , Feinlieb Manning , Sutcliffe Siobhan , Platz Elizabeth A.
Published: July 2012

Background: Obesity is associated with a variety of chronic diseases, including cancer, which may partly be explained by its influence on sex steroid hormone concentrations. However, different measures of obesity are not equally strongly associated with the risk of these diseases, and, thus, might also differently influence circulating levels of sex steroid hormones.

Objective: To estimate and compare the associations of body mass index (BMI), waist circumference, and percent body fat with circulating sex steroid hormone levels.

Methods: In our analysis, we included 1,256 men, aged 20+ years, who attended the morning examination session of the Third National Health and Nutrition Examination Survey (NHANES III; 1988-1991). Serum hormones were measured by immunoassay. Weight, height, and waist circumference were measured by trained staff. Percent body fat was estimated from bioelectrical impedance. Linear regression was used to estimate associations between body fatness measures and hormone levels adjusting for age, race/ethnicity, previously identified correlates of hormone levels, and the other hormones.

Results. Total and free testosterone and sex hormone binding globulin (SHBG) concentrations decreased with increasing BMI, waist circumference, and percent body fat (all p-trend <0.05), whereas total and free estradiol increased with increasing measures of body fatness (all p-trend <0.05). The magnitude of change in any one of these hormones was similar for a one quartile increase in each body fatness measure.

Conclusions: Measured BMI, waist circumference, and percent body fat led to similar inferences about the association between body fatness and hormone levels in men.

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 1921. doi:10.1158/1538-7445.AM2011-1921
Abstract 2003: Role of de novo DNMTs in carcinogen induced transformation of human bronchial epithelial cells
Authors: Teneng Ivo , Tellez Carmen S. , Belinsky Steven A.
Published: July 2012

Malignant tumors and cell lines are characterized by increased expression of DNMT3a and 3b. While evidence suggests that DNMT1, 3a and 3b co-operate in methylation and gene silencing during carcinogenesis, very little is known about targets for DNMT3a and 3b or their impact on the development of adenocarcinoma. We developed an in vitro model using human telomerase /cyclin dependent kinase 4 -immortalized human bronchial epithelial cell lines (HBECs) to identify key molecular changes that drive transformation and clonal outgrowth of preneoplastic lung epithelial cells during exposure to tobacco carcinogens. Carcinogen exposure (0.5µM MNU and 0.05µM BPDE) for 12 weeks induced transformation of HBEC1 and HBEC2 cells and transformation efficiency was associated with DNA repair capacity. A significant increase in DNMT1 protein was observed during carcinogen exposure while moderate increases in DNMT3a and 3b were observed in transformed cells. Increased DNMT3a and 3b levels have been reported in several cancers. We observed 5-20 fold increased expression of DNMT3a and 3b in tumor derived lung cancer cell lines. Therefore we tested the hypothesis that over expressing DNMT3a and 3b would accelerate transformation by targeting specific genes for methylation and promote full malignancy in carcinogen-treated HBECs. HBEC1 and HBEC2 clones that expressed DNMT3a or 3b at levels comparable to those observed in tumor derived cell lines were isolated, expanded and characterized. Over expression of DNMT3a or 3b had no effect on DNA repair capacity, did not affect DNMT1 expression and was not sufficient to drive transformation as evidenced by inability to form colonies on soft agar. Two clones from each cell line over expressing DNMT3a or 3b were treated with carcinogen for one hour, once a week for 12 weeks and analyzed for transformation on soft agar. Studies completed for HBEC1 indicate that expression of DNMT3b increases transformation efficiency. Soft agar analyses for HBEC2 clones are on going. Further studies will characterize the mechanism for increased transformation by examining reprogramming of the epigenome and tumorigenicity of transformed cells in xenografts

This study was supported by R01 ES008801.

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 2003. doi:10.1158/1538-7445.AM2011-2003
Abstract 202: Endogenous c-jun inhibits mammary epithelial cellular apoptosis in vivo
Authors: Katiyar Sanjay , Casimiro Mathew , Dettin Luis , Ju Xiaoming , Wagner Erwin , Tanaka Hirokazu , Pestell Richard
Published: July 2012

c-jun, which is overexpressed in a number of human cancers encodes a critical component of the AP-1 complex. c-jun has been shown to either induce or inhibit cellular apoptosis. Germ line deletion of both c-jun alleles is embryonically lethal. To determine the role of the endogenous c-jun gene in apoptosis, we performed mammary epithelial cell-targeted somatic deletion using floxed c-jun (c-jun f/f) conditional knockout mice. Laser capture microdissection demonstrated endogenous c-jun inhibits expression of apoptosis inducing genes and reactive oxygen species (ROS)-reducing genes (MnSOD, catalase). ROS have been implicated in apoptosis and undergo enzymatic elimination via MnSOD and CuZnSOD with further detoxification via catalase. c-jun-mediated survival was in part dependent on ROS production. c-jun-mediated repression of MnSOD and catalase occurred via mitochondrial complex I and NOX I. Collectively, these studies define a pivotal role of endogenous c-jun in promoting cell survival via maintaining mitochondrial integrity and expression of the key regulators of ROS production.

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 202. doi:10.1158/1538-7445.AM2011-202
Abstract 2035: Activating transcription factor 2 (ATF2) controls tolfenamic acid-induced ATF3 expression via MAP kinase pathways
Authors: Lee Seong-Ho , Bahn Jae Hoon , Whitlock Nichelle , Baek Seung J.
Published: July 2012

Tolfenamic acid (TA) is a non-steroidal anti-inflammatory drug associated with anti-tumorigenic and pro-apoptotic properties in animal and in vitro models of cancer. However, the underlying cellular mechanisms by which TA exerts its effects are only partially understood. Activating transcription factor 3 (ATF3) is a member of the ATF/CREB subfamily of the basic region-leucine zipper family and has been known as a tumor suppressor in human colorectal cancer cells. The present study was performed to observe whether ATF3 mediates TA-induced apoptosis and to elucidate the molecular mechanism of ATF3 transcription induced by TA. TA treatment and ectopic expression of ATF3 increased apoptosis whereas knockdown of ATF3 resulted in significant repression of TA-activated apoptosis. The TA treatment also induced ATF3 promoter activity. Internal deletion and point mutation of the predicted ATF/C/EBP binding site in ATF3 promoter abolished luciferase activation by TA. Overexpression of ATF2 resulted in significant increase of ATF3 promoter activity, and electrophoretic mobility shift assay identified this region as a core sequence to which ATF2 binds. TA treatment resulted in an increase of ATF2 phosphorylation, which was followed by a subsequent increase of ATF3 transcription. Knockdown of ATF2 abolished TA-induced ATF3 expression. We further provide evidence that TA leads to increases of phospho-p38 MAPK, JNK, and ERK levels. Inhibition of these pathways using selective inhibitors and dominant negative constructs ameliorated TA-induced ATF3 expression and promoter activities. The current study demonstrates that TA stimulates ATF3 expression and subsequently induces apoptosis. These pathways are mediated through phosphorylation of ATF2, which is mediated by p38 MAPK, JNK, and ERK-dependent pathways.

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 2035. doi:10.1158/1538-7445.AM2011-2035
Abstract 2040: Gene expression profile of circulating tumor cells in breast cancer by RT-qPCR
Authors: Strati Areti D. , Markou Athina , Parisi Cleio , Politaki Eleni , Mavroudis Dimitris , Georgoulias Vassilis , Lianidou Evi
Published: July 2012

Background: Circulating tumor cells (CTCs) are associated with prognosis and can be used as a liquid biopsy for repeated follow up examinations. Molecular characterization of CTCs is difficult to address since they are very rare and the amount of available sample is very limited.

Patients and methods: We quantified by RT-qPCR CK-19, MAGE-A3, HER-2, TWIST1, hTERT α+β+, and mammaglobin gene transcripts in immunomagnetically positively selected CTCs from 92 breast cancer patients, and 28 healthy individuals. We compared our results with the CellSearch system in 33 patients with early breast cancer.

Results: RT-qPCR is highly sensitive and specific and can detect the expression of each individual gene at the one cell level. None of the genes tested was detected in the group of healthy donors. In 66 operable breast cancer patients, CK-19 was detected in 42.4%, HER-2 in 13.6%, MAGE-A3 in 21.2%, hMAM in 13.6%, TWIST-1 in 42.4%, and hTERT α+β+ in 10.2%. In 26 patients with verified metastasis, CK-19 was detected in 53.8%, HER-2 in 19.2%, MAGE-A3 in 15.4%, hMAM in 30.8%, TWIST-1 in 38.5% and hTERT α+β+in 19.2%. The comparison between RT-qPCR and CellSearch, showed that RT-qPCR was more sensitive than CellSearch.

Discussion: Molecular characterization of CTCs has revealed a remarkable heterogeneity of gene expression between breast cancer patients. In a small percentage of patients, CTCs were positive for all six genes tested, while in some patients only one of these genes was expressed. The clinical significance of these findings in early breast cancer remains to be elucidated when the clinical outcome for these patients is known.

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 2040. doi:10.1158/1538-7445.AM2011-2040
Abstract 2043: BORIS directly regulates in vivo expression of the cancer testis antigen, testes-specific protease 50 (TSP50)
Authors: Suzuki Teruhiko , Kosaka-Suzuki Natsuki , Morse Herbert C. , Loukinov Dmitri , Lobanenkov Victor
Published: July 2012

BORIS (Brother of the Regulator of Imprinted Sites), also known as CTCFL, is a paralogous gene of that encoding the versatile chromatin factor CTCF. While BORIS was initially described as a testis-specific gene, recent reports showed that it is also expressed in various tumors and cancer cell lines at the transcriptional and protein levels indicating that BORIS encodes a cancer testis antigen (CTA). Interestingly, several studies have shown that BORIS regulates the expression of other CTAs including MAGE-A1 and NY-ESO-1. Gene expression profiling of testes derived from BORIS knockout and wild type mice suggested that BORIS regulates the expression of another gene encoding a CTA, testes-specific protease 50 (TSP50), also known as PRSS50. To examine this suggestion, we first performed electrophoretic mobility shift assays (EMSA) and found that the mouse TSP50 promoter region contains two BORIS binding sites. Occupancy of these sites by BORIS was confirmed by ChIP analyses of testicular chromatin. Computer analyses of the human TSP50 promoter revealed extensive homology with the mouse TSP50 promoter within BORIS binding sites. We confirmed BORIS binding to those sites by EMSA. Moreover, ChIP analyses of human cancer cell lines expressing TSP50 also showed that BORIS was bound to the promoter. Luciferase reporter assays demonstrated the importance of BORIS for the regulation of TSP50 promoter. Finally, we found that BORIS-induced expression of TSP50 is epigenetically regulated. These findings represent the first demonstration that the CTA, BORIS, itself regulates the expression of other CTAs in vivo.

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 2043. doi:10.1158/1538-7445.AM2011-2043
Abstract 2046: FoxM1 cooperates with Sp1 to transcriptionally activate the COX-2 promoter
Authors: Xu Kaiming , Shu Hui-Kuo G.
Published: July 2012

Cyclooxygenase-2 (COX-2) induction by epidermal growth factor (EGF) is likely to be an important response to this growth factor in gliomas given its prognostic significance in these tumors. Gaining a greater understanding of the signaling pathway(s) involved in this response may permit development of novel approaches for disrupting this induction with potential therapeutic benefit in such patients. Previously, we showed that p38-MAPK and protein kinase C-delta were required signal transducers in this process that ultimately leads to Sp1-dependent transcriptional activation of the COX-2 promoter in glioma cells. In this current work, we find that the FoxM1 transcription factor is also needed for full induction of COX-2 in response to EGF. Src kinase acts upstream of p38-MAPK to induce both FoxM1 and COX-2 expression. Furthermore, siRNA suppression of FoxM1 significantly reduces COX-2 induction in response to both EGF and the downstream signal transducers Src and p38-MAPK. In addition, increased expression of FoxM1 in an inducible system leads to increased COX-2 expression. Evaluation of the COX-2 promoter in a reporter gene system revealed that while FoxM1 overexpression can have a small effect on promoter activity through the FoxM1 consensus site at approximately -2.5k upstream of the promoter start site, its main activity appears to be through the Sp1 consensus site located from -245 to -240 upstream of the start site. Interestingly, FoxM1 associates with Sp1 by coimmunoprecipitation. In fact, FoxM1 can associate with the Sp1 consensus site both in vitro as assessed by electrophoretic mobility shift assay (EMSA) and in vivo as assessed by a chromatin immunoprecipitation (CHIP) assay. This work demonstrates a novel interaction between Sp1 and FoxM1 whereby FoxM1 can activate transcription of COX-2 through the associated Sp1 factor's consensus site.

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 2046. doi:10.1158/1538-7445.AM2011-2046
Abstract 2062: HIF-1 is required for ErbB2-mediated anoikis resistance
Authors: Whelan Kelly A.
Published: July 2012

We have previously established hypoxia as an inhibitor of anoikis in mammary epithelial cells as exposure to hypoxic conditions results in suppression of anoikis and delays lumen formation in 3D acinar structures. Inhibition of anoikis in this system is dependent upon both maintenance of EGFR-mediated MAPK signaling and the hypoxia-inducible transcription factor HIF-1. In an effort to determine the mechanism through which hypoxic exposure maintains MAPK signaling in MCF-10As, we compared the gene expression profiles of normoxic and hypoxic 3D acinar structures using microarray analysis. Interestingly, of the more than 70 genes found to be significantly upregulated under hypoxic conditions, a subset of genes emerged that have been implicated in oncogenesis as mediated by, a well-established regulator of anoikis resistance in breast cancer cells. Based on this intersection between HIF and ErbB2 in anoikis-associated signaling as well as the fact that oncogenes, including ErbB2, are known to stabilize HIF under normoxic conditions, we sought to determine what role, if any, HIF-1 plays in ErbB2-mediated oncogenesis. MCF-10A cells overexpressing ErbB2 indeed show increased levels of HIF-1α mRNA and protein under normoxic conditions. We show, for the first time, that depletion of HIF-1 from ErbB2-expressing cells using RNAi leads to restoration of anoikis sensitivity which is associated with both decreased Akt and Erk signaling and the induction of the pro-anoikis protein Bim. This effect was specific to anoikis as depletion of HIF-1 had no effect on survival of attached cells. Similar effects of HIF-1 depletion on anoikis resistance were seen in the human breast cancer cell line SK-BR-3 in which ErbB2 is amplified. Further, expression of at least four genes (integrin alpha 5, angiopoeitin-like 4, endothelin 2 and lysyl oxidase) identified in our microarray analysis as being upregulated by hypoxia also show enhanced expression in normoxic ErbB2-overexpressing cells as compared to parental MCF-10A cells. Here, we suggest that HIF-1 stabilization by ErbB2 under normoxic conditions is novel mechanism through which oncogenes protect cells from anoikis and plan to further explore the mechanism through which HIF-1 augments anoikis resistance in ErbB2-overexpressing cells, possibly by regulating metabolic activity. In addition, we predict that genes whose expression is upregulated by both ErbB2 and HIF-1 may serve as potential new therapeutic targets in the treatment of both hypoxic and ErbB2-positive 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 2062. doi:10.1158/1538-7445.AM2011-2062
Abstract 2068: A genome-wide siRNA screen reveals various modulators of the IRE1-XBP-1 signaling branch of the unfolded protein response
Authors: Zhang Jing , Banh Alice , Jayachandran Priya , Wollman Roy , Solow-Codero David E. , Meyer Tobias , Le Quynh-Thu , Koong Albert C.
Published: July 2012

The unfolded protein response (UPR) is an essential cellular mechanism orchestrating endoplasmic reticulum (ER) homeostasis under various cytotoxic stresses. Dysregulation of the UPR signaling pathways is linked to multiple human diseases, including cancer. The inositol requiring kinase 1 (IRE1)-X-box binding protein 1 (XBP-1) pathway is the most evolutionarily conserved signaling branch of the UPR. When activated, the endoribonuclease activity of the IRE1 cleaves the XBP-1 mRNA and generates a spliced form of XBP-1 which transcriptionally regulates cell metabolism, proliferation, survival and apoptosis. Here, we employed a genome-wide siRNA screen to systematically identify genes modulating the IRE1-XBP-1 signaling pathway of the UPR. We induced cellular ER stress with bortezomib, a proteasome inhibitor, and monitored the expression of XBP-1-luciferase fusion protein in which luciferase is fused in-frame with the spliced form of XBP-1. We identified over 100 of genes whose downregulation results in inhibition of bortezomib-induced XBP-1 splicing. These genes include diverse subsets of proteins that are involved in mRNA processing, transcription, cell cycle regulation and cell proliferation and differentiation. Furthermore, the screen reveals a connection of several oncogenes and tumor suppressors, such as Myc, Akt and cyclin K, to the UPR, underlining the important role of the IRE1-XBP-1 signaling branch in human cancers. In summary, our data suggest that the UPR is tightly connected with previously unappreciated pathways regulating various cellular processes.

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 2068. doi:10.1158/1538-7445.AM2011-2068
Abstract 2082: ERK activation mediated by Duox2 expression and reactive oxygen production is responsible for HIF-1α accumulation and VEGF induction in IFN-γ-treated BxPC-3 pancreatic cancer cells
Authors: Wu Yongzhong , Antony Smitha , Lu Jiamo , Juhasz Agnes , Liu Han , Jiang Guojian , Roy Krishnendu , Doroshow James H.
Published: July 2012

Reactive oxygen species (ROS) play an important role in tumor angiogenesis by up-regulating pro-angiogenic effectors such as HIF-1alpha and vascular endothelial growth factor (VEGF). However, the sources of ROS and the pro-angiogenic signaling pathways they target in tumor cells remain incompletely understood. We recently found that several members of the NADPH Oxidase (Nox) gene family are expressed in many human tumors; of these, Duox (Dual oxidase) 2 is highly expressed in tumors of the gastrointestinal tract. Recently, we demonstrated that IFN-gamma treatment of Bx-PC-3 cells upregulates the expression of Duox2 (and its maturation factor DuoxA2; but no other Nox isoform) leading to long-lived production of H2O2. Using this system, we investigated the role of Duox2-mediated ROS in the regulation of HIF-1alpha and VEGF expression. In BxPC-3 cells, IFN-gamma induction of Duox2/A2 expression was accompanied by both intra- and extracellular ROS accumulation, and by the simultaneous upregulation of HIF-1alpha and VEGF. However, in the MIA-PaCa-2 and PANC-1 lines that do not upregulate Duox2 following IFN-gamma exposure, no HIF-1alpha or VEGF induction was observed. In BxPC-3 cells, both the Nox inhibitor diphenylene iodonium and the ROS scavenger N-acetyl-L-cysteine suppressed IFN-gamma-induced HIF-1alpha accumulation and VEGF upregulation, suggesting that Duox2-derived ROS are involved in VEGF induction. Further experiments revealed that IFN-gamma induced a sustained activation of ERK1/2, which subsequently activated p90 ribosomal S6 kinases (RSKs) and the regulator of protein translation, ribosomal protein S6, resulting in enhanced synthesis of HIF-1alpha. ERK activation was required for IFN-gamma-induced HIF-1alpha and VEGF expression, since treatment with the MEK inhibitor U0126 completely abrogated IFN-gamma-induced HIF-1alpha and VEGF expression. Duox2-specific siRNA experiments showed that IFN-gamma-induced ROS, ERK activation, and HIF-1alpha accumulation were significantly attenuated following silencing of Duox2 expression. However, IFN-gamma-induced expression of VEGF was unchanged following Duox2 knockdown. Ongoing studies are evaluating the role of residual Duox2 or Duox2-independent pathways for VEGF activation following IFN-gamma exposure as well as other downstream, pro-angiogenic targets of Duox2-mediated HIF-1alpha expression under normoxic conditions.

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 2082. doi:10.1158/1538-7445.AM2011-2082
Abstract 2090: Investigating peroxiredoxin expression, activity, and potential downstream signaling in cancerous MCF7 and normal MCF10A breast epithelial cells
Authors: Sullivan Katie , Goncalves Kevin , Sumra Maryam , Phelan Shelley A.
Published: July 2012

Peroxiredoxins are thiol-specific antioxidant proteins that protect cells from oxidative stress. They have been implicated in cell signaling, proliferation and apoptosis, and studies have found elevated levels in many types of cancer, suggesting a protective role for these proteins in cancer cells. We previously showed that Prdx1 is overexpressed in the MCF7 breast cancer line as compared to the normal MCF10A line, and that suppression of Prdx1 and/or Prdx6 increases susceptibility to oxidative stress-induced apoptosis, with a more profound effect in MCF10A cells. In the present study, we sought to investigate other differences in peroxiredoxin expression and activity between these lines, as well as potential downstream targets. We found that mRNA levels of Prdxs1-5 were significantly elevated in MCF7 cells, while comparable levels of Prdx6 mRNA were found. A Prdx6 antibody, however, detects two bands by western blot: an upper 30-32 kDa species expressed at equal levels in both lines, and a 24-26 kDa species significantly overexpressed in MCF7 cells. An antibody specific for oxidized Prdx6 detected both products, demonstrating elevated levels in the cancer cells. Interestingly, the two species were differentially affected by siRNA-mediated Prdx1 and/or Prdx6 suppression. We further examined potential downstream targets of peroxiredoxin-regulated signaling. The two lines showed relatively comparable levels of p38, JNK1, ERK2, and c-Abl1b mRNA. In contrast, ERK1 mRNA levels were higher in MCF7 cells, while c-Abl1a was expressed only in the normal line. Peroxiredoxin suppression by siRNA transfection had no significant effect on p38, ERK1, or ERK2 in either cell type, but did lead to a decrease in c-Abl and JNK1 expression differentially in the two lines. Together, these data suggest different roles for Prdx1 and Prdx6 in normal vs. cancerous breast epithelial cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2090. doi:10.1158/1538-7445.AM2011-2090