bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5694: Zapotin mediates its action by inducing p53 in wild-type p53 positive human lung cancer cells
Authors: Kanade Geetanjali G. , Nathani Rajesh , Huma Loredana , Mehta Rajendra G. , Murillo Genoveva
Published: February 2011

Lung cancer is the most common cancer worldwide, accounting for 1.2 million new cases annually. Despite the availability of several novel medications, very few have been found to be widely applicable or effective. Hence, the aim of present study was to assess the efficacy of Zapotin, a phytochemical present in the Mexican fruit Sapote blanco (Casimiroa edulis), in lung epithelial cells. Zapotin was chemically synthesized and the effects were evaluated on several human non-small cell lung cancer cell lines (A549 (p53 wild type), Calu-1(p53 null), H1993 (p53 mutated)) and the Normal Human Bronchial epithelial cell line (BEAS-2b) using cell proliferation assay (MTT Assay & Cell count method), apoptosis assay (TUNEL Assay), western blot analysis and RT-PCR. Significant growth inhibition of 66.91% and apoptosis was found to be induced in the A549 cells when treated with 1 μM zapotin for 72 hrs. On the other hand, no significant growth inhibition was noted for Beas-2b under the same conditions. Furthermore, the western blot analyses indicated that zapotin increased p53 and p21 protein expression in A549 cells but not in Beas-2b cells. Studies for p53 mRNA expression were completed on A549 and Beas-2b subsequent to treatment with zapotin and it showed to have no significant changes. This suggested that the activation of p53 is at protein level instead of transcriptional level. This is the first report to indicate that zapotin acts through p53 mediated pathway in wild-type p53 positive A549 cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5694.
Abstract 5697: Cellular iron depletion weakens isothiocyanate-induced HO-1 upregulation
Authors: Loo George
Published: February 2011

Heme oxygenase-1 (HO-1) is an important cytoprotective gene, whose expression is known to be elevated in various carcinomas. Also, overexpression of HO-1 is known to inhibit apoptosis particularly in cancer cells. Interestingly, exposing cancer cells to certain chemopreventive agents such as isothiocyanates causes induction of HO-1, perhaps as an attempt by the cells to help them survive the stressful situation. However, it is not completely known what nutritive factors or related components in cancer cells influence HO-1 induction as caused by isothiocyanates. Thus, the aim was to test the hypothesis that adequate iron is needed to enable cancer cells to optimally express HO-1 when induced by isothiocyanates. In HCT-116 human colon adenocarcinoma cells, phenethylisothiocyanate and sulforaphane increased expression of HO-1 and also heme oxygenase activity. However, cells made iron-deficient with the iron chelator, desferrioxamine (DFO), and then exposed to isothiocyanates had much lower heme oxygenase activity. This suppressive effect of DFO on isothiocyanate-mediated induction of heme oxygenase activity was in association with repression of HO-1 protein and mRNA expression. The suppression by DFO of isothiocyanate-induced HO-1 upregulation was reversed upon replenishing the iron-deficient cells with the missing iron. Additionally, it was found that thiol antioxidants (glutathione and N-acetylcysteine) inhibited isothiocyanate-induced HO-1 upregulation, implying that the HO-1 upregulation involved an oxidant signaling pathway. Indeed, NADPH oxidase (NOX) inhibitors, namely, diphenyleneiodonium (DPI) and apocynin, and a superoxide scavenger (Tiron) inhibited isothiocyanate-induced upregulation of HO-1 as well. DPI was the most potent and also inhibited nuclear translocation of redox-sensitive Nrf-2, which is known to activate the HO-1 gene. These findings suggest the possibility that adequate amounts of iron, which at the atomic level can serve as the pivotal element of heme in NOX, must be present in the cells to permit what appears to be NOX-dependent upregulation of HO-1 by isothiocyanates. It is concluded that iron-deficient HCT-116 cells are less able to increase expression of cytoprotective HO-1 when exposed to isothiocyanates, which may make the cancer cells more susceptible to killing.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5697.
Abstract 5700: Establishing candidate biomarkers for the pharmacodynamic action of sulforaphane in the breast
Authors: Agyeman Abena , Shaw Patrick , Chaerkady Ragohthama , Tran Quynh , Sutter Thomas , Pandey Akhilesh , Visvanathan Kala , Davidson Nancy , Kensler Thomas
Published: February 2011

The goal of this study is the discovery of biomarkers reflecting the pharmacodynamic action of sulforaphane (SFN), initially in the normal human mammary epithelial MCF10A cell line and then in tissue obtained from healthy patients undergoing reduction mammoplasty surgery. SFN is formed by the hydrolysis of glucoraphanin, a water soluble glucosinolate found in cruciferous vegetables with especially high levels measured in 3 day old broccoli sprouts. Chemoprevention by SFN is achieved in part through the upregulation of cytoprotective enzymes via the Keap1/Nrf2 pathway. Preliminary dose response and time course studies in MCF10A cells established that SFN upregulated cytoprotective genes as indicated by increased levels of NQO1 transcripts, protein and activity. NQO1 induction is dependent on the Keap1/Nrf2 pathway since NQO1 transcripts, protein and activity were enhanced by KEAP1 siRNA knockdown in MCF10As. For the biomarker discovery phase isobaric tag for relative and absolute quantitation (iTRAQ) was used to quantify global protein changes using mass spectrometry. Two independent 8-plex iTRAQ experiments determined the pharmacological actions of SFN on protein expression, compared to a vehicle control, and the genetic regulation of protein expression following knockdown of KEAP1 compared to a non targeting control siRNA. In both experiments protein expression was analyzed at 12, 24, 48, and 72 hour time points after SFN treatment or KEAP1 knockdown. In addition to confirming NQO1 to be a good candidate biomarker, the iTRAQ analysis identified other upregulated candidates to be aldo-keto reductase family 1 member C1 (AKR1C1), DJ-1 protein, and thioredoxin. NQO1 and AKR1C1 transcripts were also elevated in the MCF10A cells, as assessed by microarray assay. Candidate biomarkers identified from microarray and iTRAQ studies reflecting the pharmacodynamic action of SFN in human cells will be analyzed by Western blot, qRT-PCR and enzyme assays in tissue from reduction mammoplasty patients. These women have been randomized in a clinical trial to receive either a broccoli sprout preparation containing 100 micomole SFN or a placebo beverage daily for 10 days prior to surgery. Supported by P50 CA088843, U54 RR020839 and BC073262.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5700.
Abstract 5707: Effects of non-toxic agents and their combinations on genotoxicity-related endpoints, and mutagenesis induced by dimethylbenzanthracene-dihydrodiol in cultured rat mammary cells
Authors: Sacks Peter G. , Zhao Zhong-Lin , Kosinska Wieslawa , He Zhiming , Vucetic Zeljka , Ngai Alvin , Guttenplan Joseph B.
Published: February 2011

As the annual breast cancer incidence in the US is about 200,000, prevention would be of enormous value. There are many leads from studies in isolated cell systems and experimental animals, but when individual putative protective agents have been tested in humans, results have been equivocal or negative. Levels generally present in foods, beverages or supplements may exert only weak protective effects, and combinations of potential chemopreventives may be necessary for effective cancer prevention. Here we investigated combinations of non-toxic nutraceutical agents dosed at or near physiological levels, for their abilities to modulate xenobiotic metabolism, and mutagenesis induced by the proximate rat mammary carcinogen, 7,12-dimethylbenzanthracene-dihydrodiol (DMBAD), in rat mammary epithelial cells. The agents and their 1x concentrations, were: resveratrol (Res), 2.4 μM; sulforaphane (Sul), 0.015 μM; antioxidant mix (α-, γ-tocopherol, 30 μM, Vitamin C, 68 μM (VCE); α-lipoic acid (LA), 2 μM; epigallocatechin gallate, (EGCG) 0.7 μM; and N-acetylcysteine (NAC), 12 μM). All of the single agents were non-toxic at the 1x doses and had no statistically significant effect on cell proliferation. All combinations of the binary agents were non-toxic and several modestly inhibited cell proliferation: EGCG-NAC, 27% inhibition, EGCG-Res, 21% inhibition, EGCG-VCE, 26% inhibition. For protection against oxidative stress, inhibition of the oxidation of dihydrodichlorofluorescinediacetate (DHDCF) was monitored, and NAC and NAC+Res or EGCG produced small (10-20%) inhibition. The effects of the inhibitors on selected phase I and II gene expression were also examined. EGCG, Sul, VCE and Res alone induced NQO1, (often used as a marker of phase II, detoxification activity) expression and did not induce CYP1A1 or 1B1. In mutagenesis experiments most of the individual agents did not result in statistically significant inhibition of mutagenesis, but some led to minor inhibition (ca. 20%). We also tested several binary combinations of agents, and some of these led to significant inhibition of mutagenesis. The combinations, NAC + Sul, NAC + Res, and NAC + LA inhibited mutagenesis by 25 - 50% at or near physiologic levels. In conclusion, several non-toxic agents favorably affected expression of genes involved in polycyclic aromatic hydrocarbon-induced carcinogenesis, and several combinations of these agents inhibited cell proliferation, and mutagenesis in cultured rat mammary cells by DMBAD. Supported by the Susan Komen Foundation grant # KG080836.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5707.
Abstract 5713: Omega-3 fatty acid molecular and cellular modulation of in vitro models of high-risk breast cancer
Authors: Chen Ching Hui , Cavazos David A. , Apte Shruti A. , Fabian Carol , Hursting Stephen , deGraffenried Linda A.
Published: February 2011

Omega-3 (n-3) fatty acids, especially the long-chain polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaonoic acid (DHA), have been shown to have potential antitumor effects for a wide range of cancer types, including breast. Multiple and widely diverse mechanisms have been purported through which n-3 fatty acids act as antitumor agents. Due to this wide range of effects, the n-3 fatty acids EPA and DHA in particular have been extrapolated to be possible chemo-preventive agents. Recent epidemiological studies have demonstrated that high intake of n-3 fatty acids from fish is inversely correlated with breast cancer risk. In this current study, we explore the molecular and cellular effects of EPA and DHA in breast cancer cells demonstrating abnormalities similar to those found in high risk patient populations, including MCF-7 cells with stable suppression of PTEN expression, MDA-MB-231 cells that mimic the triple negative phenotype and mouse epithelial cells that are derived from MMTV-erbB2 mouse breast tumors. Loss of PTEN activity has been reported in as much as 50% of all breast cancers. Triple negative disease exhibits an aggressive and early pattern of metastasis, with limited treatment options and a poor prognosis. ErbB2 is overexpressed in 30% of breast tumors and has been associated with a more aggressive and a pro-inflammatory disease. Based upon the highly inflammatory nature of these three cell types, we hypothesized that omega-3 fatty acids would be effective in modulating cellular processes that promote the more aggressive phenotype associated with these abnormalities. We are investigating the effect of EPA and DHA on survival, proliferation and apoptosis of the three modulated cell lines in comparison to less aggressive cell lines, and the molecular changes that correlate with response. Preliminary data suggest that cell proliferation is not modulated by exposure to either EPA or DHA. However, both EPA and DHA effectively suppressed NF-kB transcriptional activity in these cells. These data suggest that one important mechanism by which omega-3 fatty acids may function as anti-tumor and possibly chemo-preventive agents is through regulation of NF-kB-induced inflammation. Studies are currently on-going to evaluate if modulation of NF-kB is critical for mediating the protective effects of omega-3 fatty acids on breast cancer development and progression and if reduction of inflammatory responses will correlate with a less aggressive disease in these cells that closely reflect high risk patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5713.
Abstract 5715: Green tea polyphenols implants are more effective than oral dosing in inhibiting benzo[a]pyrene-induced DNA adducts
Authors: Cao Pengxiao , Vadhanam Manicka V. , Gupta Ramesh C.
Published: February 2011

Green tea is drawing increasing attention due to its potential chemopreventive effect. The polyphenols, including epigallocatechin gallate, epicatechin gallate, epigallocatechin and epicatechin in green tea, are believed to be the active components. However, epidemiological and clinical studies have shown mixed results presumably due to lack of bioavailability when given orally. In this study, polyphenon E, a standardized green tea extract, was administered by novel polycaprolactone implants (two, 2-cm implants; 20% drug load) grafted subcutaneously or by drinking water (0.8% w/v) to female S/D rats. Animals were then challenged with subcutaneous benzo[a]pyrene (BP) implants (2 cm; 10% load), and euthanized after 1 week. Analysis of the lung DNA by 32P-postlabeling showed a significant reduction (50%; p=0.023) in BP-induced DNA adducts in the implant group. A modest (34%) but statistically insignificant adduct reduction was also observed in the drinking water group. The dose of polyphenon E administered by implants was found to be >100 times lower than that by oral route (15.7 mg vs. 1,632 mg). No evidence of toxicity associated with either the polymeric materials or the compounds was found in all these groups based on the body weight and tissue weights. To determine possible mechanisms of action of polyphenon E, we analyzed CYP1A1, CYP1B1 and GST at mRNA and protein expression levels and for the enzyme activities. However, no evidence was found for favorable modulation of these phase I and phase II enzymes by polyphenon E. In in vitro studies, reaction of benzo[a]pyrene-7,8-diol-9,10-epoxide (anti-BPDE) with DNA was found to be strongly inhibited by individual catechins, particularly epigallocatechin gallate, present in polyphenon E, suggesting quenching of the electrophilic metabolite by the catechins. This notion was confirmed by reaction of anti-BPDE with individual catechins by LC/MS/MS. In conclusion, our study demonstrated that i) the effective dose of polyphenon E administered by polymeric implants was over 100-fold lower than the traditional oral route; and ii) polyphenon E exert their chemopreventive effect, at least, in part, due to direct quenching of anti-BPDE (Supported from CA-118114, KLCRP grant and Agnes Brown Duggan Endowment).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5715.
Abstract 5718: Convergence of vitamin D and PPARγ signaling in human breast cancer cell lines
Authors: Alimirah Fatouma , Mehta Rajendra G. , Peng Xinjian
Published: February 2011

Previous studies have demonstrated a positive interaction between vitamin D and peroxisome proliferator- activated receptor γ (PPARγ) mediated signaling while other studies have shown an inverse relationship between these two pathways. Therefore, we sought to determine the functional interaction between the vitamin D receptor (VDR) and PPARγ in human breast cancer cells. We report the physical interaction and nuclear colocalization of VDR and PPARγ in the T47D human breast cancer cell line as determined by co-immunoprecipitation and immunofluorescence respectively. Furthermore, 1alpha,25-dihydroxyvitamin D3 (1,25D3) treatment of MCF-7 and T47D cells significantly upregulated PPARγ protein expression in a dose and time dependent manner. Conversely, knockdown of unliganded VDR also upregulated PPARγ protein expression, suggesting that it is a potential VDR target gene. Thus, VDR itself in the absence of ligand, can suppress PPARγ basal expression. This paradoxical effect may be due to the differential binding of VDR to its coactivators or corepressors during the liganded and unliganded state. Consistent with this, the basal expression of PPARγ mRNA was inversely correlated with VDR mRNA expression in several human breast cancer cell lines. Reciprocally, a PPARγ agonist attenuated vitamin D mediated upregulation of vitamin D target genes CYP24 and p21. Similarly, the activity of VDRE, a vitamin D responsive reporter was decreased by 2 fold in the presence of the PPARγ agonist. Together, these observations infer that VDR and PPARγ protein interactions negatively influence their respective pathways. (This work was supported by NCI predoctoral fellowship 1F31CA132619 (F.A.) and NCI R03 CA121365 (X.P).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5718.
Abstract 5732: Human papillomavirus infection in Southern Chinese women - a population-based study
Authors: Liu Stephanie S. , Chan Kelvin KY , Leung Rebecca CY , Luk May HM , Lo Sue ST , Fong Daniel YT , Cheung Annie NY , Lin Zhong Qiu , Ngan Hextan YS
Published: February 2011

Cervical cancer is a leading cause of death in women worldwide. Persistent infection of high-risk (HR) type human papillomavirus (HPV) is recognized as a necessary cause of cervical cancer. Additionally, the presence of certain predisposing factors in combination of HPV infection will significantly increase the risk of developing cervical cancer. Previous epidemiological studies showed different HPV genotype prevalence between different geographic regions. The objectives of the present study were to study and compare the prevalence and the spectrum of HPV infection in healthy women living in Hong Kong (HK) and Guangdong (GD) regions of China and the association between the potential risk factors and HPV infection.

This was a cross-sectional study, and 1526 and 1300 healthy women were recruited from HK and GD, respectively. The overall and type-specific HPV prevalence were studied and compared between the two regions. The results showed that healthy women in GD with normal or abnormal cytology had significantly higher HPV prevalence (10% or 54.5%) than those in HK (6.2% or 33%, p≤0.001). The patterns of age-specific HPV prevalence were also different between the two regions. In HK, the highest HPV prevalence was in the youngest (20-30 years) and the eldest (60 and above) age groups, whereas the highest HPV prevalence in GD was observed in the youngest age group (20-30) and declined as the age increased. HPV16 and HPV52 were the most common high-risk type found in HK and GD, respectively. In HK, younger women had significantly higher risk of HPV infection, whereas lifetime number of sexual partner was strongly associated with the risk of HPV infection in GD. Lack of previous cervical screening, current smoker and having previous sexual transmitted diseases had increased risk of HPV infection for women in both regions.

In summary, the overall and type-specific HPV prevalence were found different in healthy women between HK and GD. Together with the understanding of the association between the potential risk factors and HPV infection will be essential for the implementation of effective public health program for prevention of cervical cancer in Southern Chinese women.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5732.
Abstract 5738: Spectrum of malignancies in patients with end-stage renal disease
Authors: Shebl Fatma M. , Engels Eric A.
Published: February 2011

Background: Patients with end-stage renal disease (ESRD) are prone to many complications and high mortality. Overall, ESRD patients are at modestly increased cancer risk. Potential mechanisms by which ESRD might induce cancer include underlying medical conditions, altered immune status due to uremia, and medical treatments. Associations with specific cancers have not been widely studied.

Methods: We conducted a population-based case-control study among elderly U.S. adults using Surveillance, Epidemiology, and End Results (SEER) Medicare linked data. After excluding individuals with HIV or history of organ transplant, the study included 1,029,695 cancer cases (identified in SEER) and 99,610 controls, frequency matched by gender, race, age, and calendar year (1992-2007). ESRD was defined by presence of Medicare claims for dialysis in each of the 3 months prior to selection. Logistic regression was used to calculate odds ratios (ORs) adjusted for matching factors.

Results: ESRD was present in 0.33% of cancer cases vs. 0.31% of controls (OR 1.13; 95%CI 1.0-1.27, p=0.04). We observed significant excess risk of cancers of the stomach (OR 1.67; 95%CI 1.34-2.08), small intestine (2.02; 1.31-3.12), colon (1.29; 1.11-1.51), liver (1.72; 1.38-2.15), pancreas (1.35; 1.09-1.68), lung (1.30; 1.13-1.49), cervix (1.94; 1.25-3.00), vagina (3.08; 1.43-6.64), penis (4.81; 2.60-8.91), bladder (1.37; 1.14-1.65), and kidney (2.58; 2.14-3.11), as well as multiple myeloma (1.92; 1.51-2.44), and chronic myeloid leukemia (2.04; 1.26-3.29). Significantly decreased risk was observed for prostate cancer (OR 0.49, 95%CI 0.41-0.59). Of note, risk of cancer of the colon, liver, vagina, penis, and kidney, and chronic myeloid leukemia increased with duration of dialysis (p-trend<0.01). Additional analyses for histologic subtype will be presented.

Conclusions: ESRD was associated with a slight overall elevation in cancer risk but much stronger increases for specific cancers. Increased risks for infection-related cancers (anogenital, liver, and stomach cancers) may reflect immunodeficiency. Excess risks were observed for malignancies (bladder and kidney cancers, myeloma) that could directly lead to ESRD or are related to such conditions. Associations with prostate and colon cancers could reflect cancer screening patterns. Further investigation of the biological pathways underlying the development of cancer in ESRD is needed.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5738.
Abstract 574: 1,4-phenylenebis(methylene)selenocyanate (p-XSC) inhibits mammalian target of rapamycin complex 2 (mTORC2) signaling in prostate cancer cells
Authors: Facompre Nicole , Sinha Indu , Pinto John , El-Bayoumy Karam , Sinha Raghu
Published: February 2011

The lack of treatment for worried-well patients with high-grade prostatic intraepithelial neoplasia combined with issues of recurrence and hormone resistance in prostate cancer survivors remains a major public health obstacle. The long latency of prostate cancer development provides an opportunity to intervene with mechanistically-based agents at various stages of disease progression. Preclinical studies and immunohistochemical analyses of human prostate adenocarcinoma tissues have implicated the mammalian target of rapamycin (mTOR) signaling pathway in the progression of prostate cancer and its transition to androgen independence, suggesting mTOR as a potential target for new therapies. Preclinical studies in human prostate cancer cells also show that there is cross-talk between mTOR and androgen receptor signaling, a process critical for prostate cancer growth and survival. We have previously shown that the synthetic organoselenium compound p-XSC effectively inhibits cell viability and down-regulates androgen receptor expression and transcriptional activity in androgen responsive (AR) and androgen independent (AI) human prostate cancer cells; the naturally occurring selenomethionine was either ineffective or weakly active at non-physiological levels. Therefore, we focused our study on the effects of p-XSC and we hypothesized that it inhibits prostate cancer cell growth by interfering with mTOR signaling and that inhibition of this pathway may be linked to down-regulation of androgen receptor signaling in these cells. Here we show that p-XSC inhibits phosphorylation of mTOR in both AR LNCaP and AI LNCaP C4-2 human prostate cancer cells. This inhibition is attenuated by stimulation with androgens in AR LNCaP but not AI C4-2 cells, emphasizing a cross-talk between the two pathways. p-XSC also decreases mTOR binding to mTOR complex 2 (mTORC2) protein Rictor in AR LNCaP and AI C4-2 cells and inhibits the phosphorylation of mTORC2 downstream target Akt. Since p-XSC appears to be inhibiting mTORC2 as well as androgen signaling, we further hypothesized that the combination of p-XSC with rapamycin, which primarily targets mTORC1, may be a superior approach to inhibit prostate cancer cell growth than either agent alone. Our data clearly support this hypothesis. Validation of mTOR as a target of selenium in prostate cancer will provide evidence for its potential role against advanced and hormone refractory prostate disease either individually or in combination with therapies that target other signaling pathways. Support: NIH CA111842, DOD W81XWH-08-1-0297

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 574.
Abstract 5746: Circulating cytokine levels, Epstein-Barr viremia and risk of AIDS-related non-Hodgkin lymphoma
Authors: Rabkin Charles S. , Engels Eric A. , Landgren Ola , Schuurman Rob , Goedert James J.
Published: February 2011

BACKGROUND: Human immunodeficiency virus (HIV) infection may lead to cytokine dysregulation and decontrol of Epstein-Barr virus (EBV) latency as potential mechanisms for acquired immunodeficiency syndrome (AIDS)-related non-Hodgkin lymphoma (NHL). We therefore examined pre-diagnosis blood levels in AIDS-related NHL cases from three prospective cohort studies of HIV infection. METHODS: Plasma or serum were obtained from cases (n=66) 0.1 - 2.0 (median 1.0) years pre-NHL and from up to three HIV-positive lymphoma-free controls (n=186) sampled at comparable times, matched for cohort, age, race, sex and CD4 count at time of diagnosis. Cytokine measurements used Millipore 30-plex Luminex assays with values normalized by log-transformation; coefficients of variation for blinded replicate samples ranged from 10% - 46%. EBV free viremia was detected by real-time polymerase chain reaction (PCR) assays for the BNRF p143 gene; plasma samples originally collected with heparin anticoagulation (n=110) could not be assessed because of PCR inhibition. Statistical analyses were performed by conditional logistic regression for matched sets. RESULTS: Fifty-seven cases had at least one matched control, with mean (median) CD4 counts of 172 (86)/mm3 for cases and 174 (85)/mm3 for controls. Cases had significantly higher cytokine levels for nine of the 30 measured cytokines, with p<.01 for granulocyte-monocyte colony-stimulating factor (GM-CSF) and interleukin (IL)-15, and p<.05 for IL-1a, IL-4, IL-6, IL-8, IL-12 p40, IL-12 p70 and IL-13. Stepwise selection of a multivariable conditional model identified GM-CSF, IL-12p70 and IL-15 as the most predictive markers, with matched odds ratios (95% confidence intervals) of 1.5 (0.9 - 2.4), 1.5 (0.9 - 2.5) and 1.3 (0.9 - 1.9), respectively. EBV PCR-positivity had a matched odds ratio of 1.6 (0.5-5.0), based on serum and acid-citrate-dextrose plasma samples only. CONCLUSIONS: We found elevations of T-helper type-(Th)1, Th2 and pro-inflammatory cytokines and growth factors up to two years before AIDS-NHL; EBV viremia was not significantly predictive but statistical power was limited. Cytokine hyperstimulation of B-cell proliferation may be an important etiologic pathway to AIDS-related NHL.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5746.
Abstract 5747: Anti-inflammatory nutrients and prostate cancer survival in the Örebro Prostate Cancer Survivors Cohort
Authors: Meyer Mara S. , Kasperzyk Julie L. , Andrén Ove , Wolk Alicja , Håkansson Niclas , Andersson Swen-Olof , Johansson Jan-Erik , Fall Katja , Mucci Lorelei A.
Published: February 2011

While many studies examine diet and prostate cancer (PCa) risk, few have assessed whether diet could influence prostate cancer-specific survival. Dietary factors that modulate the inflammatory response may alter clinical outcome, as chronic systemic inflammation may enhance PCa progression. As such, dietary zinc and fatty acids affecting the inflammatory response are promising targets for secondary prevention to impact survival after diagnosis.

We studied intake of dietary zinc and fatty acids in relation to cancer survival within the Örebro Swedish Cohort, including 525 confirmed PCa cases living in Örebro County who were diagnosed from 1989 to 1991. At the time of diagnosis, dietary data was collected by food frequency questionnaire specific to the Swedish diet. Use of dietary supplements was negligible in this population, which was assembled before the introduction of PSA testing. We studied intake of zinc and fatty acids (quartiles) and time to death (all cause and PCa-specific through Februrary 2009) using Cox proportional hazards models adjusted for lifestyle and clinical factors. Analyses were also stratified by clinical stage at diagnosis (early: T0-T2/M0, and advanced: T3-T4/M0/M1).

During follow-up, 218 men died from PCa and 257 from other causes. Zinc was not significantly associated with overall PCa-specific mortality, total mortality or in men diagnosed at an advanced stage. Yet among those diagnosed at an early stage, men with the highest zinc intake were 74% less likely to die of PCa (95% CI:0.10-0.68, ptrend=0.005) compared to lowest. High versus low intake of marine omega-3 docosahexaenoic acid (DHA) was associated with a reduced risk of PCa mortality overall (OR: 0.70, 95% CI: 0.47-1.03, ptrend=0.26), particularly among men diagnosed at an early stage (OR: 0.55, 95% CI: 0.23-1.58). DHA was not associated with death from other causes (OR: 1.07, 95% CI: 0.74-1.55, ptrend=0.68). The highest quartiles of saturated (HR: 1.15, 95% CI: 0.78-1.69), monounsaturated (HR: 1.18, 95% CI: 0.80-1.75) and polyunsaturated (HR: 0.90, 95% CI: 0.62-1.31) fatty acids were not associated with PCa survival.

Our results suggest men diagnosed at early stage prostate cancer may be sensitive to dietary zinc levels, which may prolong disease-specific survival. Omega-3 DHA may also be beneficial against prostate cancer-specific mortality, with inflammation being a potential common mechanism. Further research is needed to confirm these findings.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5747.
Abstract 575: A subset of small cell lung cancer (SCLC) cell lines are Mcl-1-dependent and undergo apoptosis in response to Flavopiridol-mediated inhibition of cyclin-dependent kinase (cdk) 9
Authors: Qi Li , Shapiro Geoffrey I.
Published: February 2011

Small cell lung cancer (SCLC) accounts for approximately 13% of lung cancer cases. Although SCLC is initially a chemosensitive disease, the development of resistance is a major obstacle. Recently, multiple SCLC cell lines have been found to be responsive to a Bcl-2/Bcl-xL inhibitor, ABT-737, both in vitro and in vivo (Oltersdorf T et al. Nature. 2005 Jun 2; 435(7042): 677-81). Clinical trials of the related orally-available compound ABT-263 have shown promising activity in SCLC patients. However, a subset of SCLC cell lines that express Mcl-1, another anti-apoptotic protein, are resistant to ABT-737 treatment. Furthermore, SCLC lines have elevated expression of Mcl-1 when they become resistant to ABT-737 (Tahir SK et al. Cancer Res. 2007 Feb 1; 67(3): 1176-83). Therefore drugs targeting Mcl-1 may be particularly useful in this disease. Here, we have investigated dependence of a panel of SCLC cell lines on Mcl-1 for survival, using Mcl-1 knockdown achieved by lentiviral-based shRNA technology. Several SCLC cell lines expressing Mcl-1, including NCI-H82 and SHP77 cells, demonstrate apoptosis by TUNEL assay and reduced viability by MTS assay in response to Mcl-1 depletion. However, other SCLC cell lines, including NCI-H69 and SW1271, are not responsive to Mcl-1 knockdown. We have also investigated the efficacy of Flavopiridol, a potent inhibitor of cdk9, against a panel of SCLC cell lines. Flavopiridol acutely down-regulates Mcl-1 expression in NCI-H82, SHP77, H69 and SW1271 cells. Mcl-1-dependent cell lines, including H82 and SHP77, undergo abrupt apoptosis in response to Flavopiridol. In contrast, H69 and SW1271 cells, which were not found to be Mcl-1-dependent, were not effectively killed by Flavopiridol. These data suggest that Mcl-1-dependent SCLC cells may be particularly sensitive to Flavopiridol treatment to overcome ABT-737 resistance. Finally, we have demonstrated that the combination of Flavopiridol and ABT-737 can synergistically kill both Mcl-1-dependent and -independent SCLC cells, with significantly reduced viability in SHP77 and SW1271 cells compared to treatment with either drug alone. Taken together, our studies suggest Flavopiridol-mediated cdk9 inhibition may effectively target Mcl-1 dependent SCLCs, including those resistant to Bcl-2/Bcl-xL inhibition.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 575.
Abstract 5750: Reproductive factors and risks of biliary tract cancers and stones: population-based study in Shanghai, China
Authors: Andreotti Gabriella , Hsing Ann
Published: February 2011

Biliary tract cancers, encompassing tumors arising from the gallbladder, extrahepatic bile ducts, and ampulla of Vater, are relatively uncommon but highly fatal. Higher parity has been linked to increased risks of gallbladder cancer and gallstones, but the effects of other reproductive factors are less clear. Thus, we examined the association between reproductive factors and the risks of biliary tract cancers and biliary stones among women in a population-based case-control study in Shanghai, China. A total of 361 incident biliary tract cancer cases (269 gallbladder and 92 extrahepatic bile duct), 647 biliary stone cases, and 586 healthy women randomly selected from the population were included. High parity, early age at first birth, and late age at menarche contributed to a higher risk of gallbladder cancer risk, particularly among women with associated biliary stones. Among women with stones, those who had 4 or more children and had their first child before the age of 23 had a 3.3-fold (95% CI 1.06-10.03) risk of gallbladder cancer, while those with menarche at 16 years or later had a 4.0-fold (95% CI 1.19-13.58) risk. Among parous women, breastfeeding was associated with a reduced risk of bile duct cancer (OR=0.40, 95% CI 0.20-0.81). In contrast, menopausal status, age at menopause, duration of menstruation, and oral contraceptive use were not associated with biliary tract cancer risk. No association was found between biliary stones and any of the reproductive factors examined. Our results provide further support for a role of reproductive factors, especially high parity and late age at menarche, in the development of gallbladder cancer among women with biliary stones.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5750.
Abstract 5752: Molecular mechanisms driving oncogenesis in KRAS mutant non-small cell lung cancer
Authors: Holderfield Matthew , McCormick Frank , Nagel Tobi
Published: February 2011

The poor prognosis associated with Non Small Cell Lung Cancers (NSCLC) harboring KRAS mutations (∼20-30% frequency) has highlighted the need for RAS targeted therapeutics in oncology for decades. However, attempts to target RAS directly using small molecule inhibitors have historically proven unsuccessful. Additionally, pre-clinical data repeatedly demonstrates that KRAS mutated cancer cells show variable responses to inhibition of downstream effectors, RAF, MEK and PI3K, suggesting that proliferation and survival may be driven through additional pathways and that the molecular mechanisms through which KRAS drives oncogenesis have yet to be fully elucidated. Moreover, parallel pathways activated in human lung cancer that might cooperate with RAS to maintain a transformed state, likewise remain poorly defined. By screening a panel of KRAS mutant NSCLCs for functional dependence on KRAS by shRNA knockdown, we have identified cell lines that require KRAS for proliferation and suppression of apoptosis. In an effort to identify the signaling pathways that promote cellular proliferation and survival in KRAS-mutant lung cancers we have conducted an unbiased cellular screen to identify shRNAs that mitigate dependence on the KRAS oncoprotein. Using this method we have identified molecular pathways that appear to cooperate with the KRAS oncogene to promote tumorogenesis and contribute to the distinct proliferative and apoptotic phenotypes of KRAS dependent NSCLC cell lines.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5752.
Abstract 5754: Identification of pharmacologically tractable genes that are associated with oncogenic K-Ras dependency in colorectal cancers
Authors: Singh Anurag , Sweeney Michael F. , Greninger Patricia , Settleman Jeffrey E.
Published: February 2011

Summary

We have previously shown that KRAS mutant lung and pancreatic cancer cells can be classified into two broad groups based on their requirement or dependency for sustained K-Ras activity. By supervised gene expression analyses, we derived a gene expression signature associated with K-Ras dependency, components of which represent candidate therapeutic targets. We have applied this strategy to KRAS mutant colorectal cancers (CRCs), which are notoriously refractory to conventional and targeted therapeutics. Moreover, the KRAS gene is now routinely sequenced to identify CRC patients that harbor KRAS mutations. Thus, patients with KRAS mutation-positive CRCs are given little recourse in terms of treatment options. We have found that, like lung and pancreatic cancer cell lines, KRAS mutant can be classified into K-Ras dependent and K-Ras independent groups. However, whereas K-Ras dependency in KRAS mutant lung and pancreatic cancer cells is associated with a well differentiated epithelial-like phenotype, K-Ras dependent CRC cells do not exhibit such an association. As such K-Ras dependent CRC cells exhibit a distinct molecular profile compared to K-Ras dependent lung and pancreatic cancer cells. We have identified a number of distinct kinase genes whose expression is associated with K-Ras dependency specifically in CRCs. Depletion of these genes by RNAi results in selective cytotoxic effects in K-Ras dependent CRC cells, suggesting that these genes may serve as candidate therapeutic targets in a subset of KRAS mutant CRCs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5754.
Abstract 5757: A genome-wide screen for microdeletions reveals disruption of polarity complex genes in diverse human cancers
Authors: Rothenberg Stephen M. , Mohapatra Gayatry , Rivera Miguel N. , Winokur Daniel , Greninger Patricia , Cohen Ezra E.W. , Louis David N. , Settleman Jeffrey , Haber Daniel A.
Published: February 2011

In a genome-wide screen of 684 cancer cell lines, we identified homozygous intragenic microdeletions involving genes encoding components of the apical-basal cell polarity complexes. Among these, PARD3 is disrupted in cell lines and primary tumors from squamous carcinomas and glioblastomas. Reconstituting PARD3 expression in both cell types restores tight junctions and retards contactdependent proliferation. Searching specifically for small intragenic microdeletions using high resolution genomic arrays may be complementary to other genomic deletion screens and resequencing efforts in identifying new tumor suppressor genes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5757.
Abstract 5759: The landscape of copy-number changes across multiple human cancer types
Authors: Beroukhim Rameen , Meyerson Matthew , Garraway Levi , Prensner John
Published: February 2011

Genomic regions undergoing frequent alteration in human cancers often point to genes that play causal roles in oncogenesis. We have performed high-resolution analyses of copy-number alterations from 3131 cancer specimens across multiple histological types. We identified 158 regions of that are significantly altered by focal copy-number changes. Among these, 122 regions cannot be explained by the presence of a known cancer gene. Several gene families are enriched among these regions, including the BCL2 family of apoptosis regulators and the NF-κB pathway. Cell lines with amplifications of the anti-apoptotic genes MCL1 and BCL2L1 depend upon these genes for survival. Finally, we find that the majority of copy-number changes identified in individual cancer types are present across multiple cancer types.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5759.
Abstract 576: Hydrogen peroxide and iron released from nitroprusside cooperate to induce melanoma cell death: role of the p53 genotype
Authors: Gomez Luis A. , Strasberg Mary , Rieber Manuel
Published: February 2011

BACKGROUND. We recently reported that sodium nitroprusside or nitroferricyanide (III) (SNP), an iron nitrosyl complex clinically used as a powerful vasodilator, promotes melanoma cell apoptosis independently of the status of the p53 tumor suppressor gene. This occurred with intact SNP but was delayed when using its light-exhausted form (lex-SNP) devoid of nitric oxide (NO) (1). OBJECTIVES. Since extracellular NO and hydrogen peroxide (H2O2) are increased after SNP treatment (2), to define antitumor effects of H2O2 plus NO or iron, we used sub-toxic exogenous H2O2 singly or together with either: a) SNP; b) lex-SNP; c) potassium ferricyanide or d) ferric ammonium sulphate, against genetically-matched human C8161 melanoma harboring wild type (wt) or mutant p53, since the latter contributes to drug resistance. METHODS. Cell survival was assayed by crystal violet staining or by determining percentage of calcein AM retention and lack of propidium iodide uptake. DNA damage was assessed by laser scanning cytometry and PARP fragmentation was measured by immune blotting. RESULTS. While each treatment alone showed low efficacy, a synergistic cytotoxicity was demonstrated only between either intact or lex-SNP + H2O2. Shorter treatments of these combinations were preferentially cytotoxic against wt p53 melanoma compared to their mutant p53 matched counterparts, in crystal violet survival assays. However, longer treatments with [SNP + H2O2] induced apoptosis-associated PARP cleavage irrespective of cellular p53 genotype. All these changes were antagonized by anti-oxidant N-acetyl cysteine (NAC) or metal chelator o-phenanthroline, suggesting that metal-dependent redox changes are important in this anti-tumor activity. CONCLUSIONS. When using alternative iron sources like those provided by potassium ferricyanide, ferric ammonium sulphate or sodium nitroferricyanide (III) (SNP), we show for the first time that in vitro anti-tumor combination therapy with sub-toxic H2O2 is achieved only with iron made available by SNP, since H2O2 did not synergize with iron provided by potassium ferricyanide or ferric ammonium sulphate. Lex-SNP devoid of NO (1) also potentiated the effect of H2O2, implying that the cooperative effect of [SNP + H2O2] is independent of its NO-donating ability.

REFERENCES

(1) Gomez-Sarosi LA, Strasberg-Rieber M, Rieber M. ERK activation increases nitroprusside induced apoptosis in human melanoma cells irrespective of p53 status: role of superoxide dismutases. Cancer Biol Ther 2009; 8:1173-82. (2) Rabkin SW and Kong JY. Nitroprusside induces cardiomyocyte death: interaction with hydrogen peroxide. Am J Physiol Heart Circ Physiol 2000; 279:H3089-H3100.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 576.