bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A66: Expression and immunotherapeutic targeting of the SSX family of cancer-testis antigens in prostate cancer
Authors: Smith Heath A. , Cronk Robert J. , Lang Joshua M. , McNeel Douglas G.
Published: June 2012

Members of the SSX family of proteins were among the first cancer-testis antigens (CTA) identified. Characterized by tissue-restricted expression to MHC class l-deficient germline cells and frequent ectopic expression in tumors of various histological origin, CTA are highly tumor-specific antigens. SSX proteins comprise a family of ten members with mRNA expression often found in advanced-stage disease and associated with worse patient prognosis. We have previously shown that humoral and cell-mediated immune responses to SSX2 can arise spontaneously in patients with prostate cancer, which combined with the expression of these proteins in MHC class l-negative tissue, makes SSX proteins potentially attractive targets for tumor immunotherapy. In the current study, we evaluated SSX family member expression in prostate cancer cell lines and tumor biopsies to identify therapeutic targets for vaccine therapy in prostate cancer. We found by RT-PCR and qRT-PCR that SSX1, SSX2, and SSX5 were frequently expressed in prostate cancer cell lines and could be induced by treatment with epigenetic modifying agents (EMA) such as 5-aza-2′-deoxycytidine. Furthermore, we observed differential SSX protein expression in paraffin-embedded prostate cancer biopsies on tissue microarray by immunohistochemical staining. Interestingly, SSX expression in patient samples was restricted to metastatic prostate cancer lesions (5/22; 23%), while expression in primary prostate tumors was not observed (0/73). Finally, we determined that it is possible to elicit cross-reactive immune responses to a dominant SSX epitope p103–111 shared by the different SSX family members by immunization of A2/DR1 transgenic mice with SSX peptides or a plasmid DNA vaccine encoding SSX2. Overall, these results suggest that multiple SSX family members are expressed in prostate cancer and can be simultaneously targeted using immunotherapeutic vaccines.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr A66.
Abstract B11: Development and validation of HPV-16 chimeric VLPs and peptide as vaccine candidates against cervical cancer
Authors: Singh Neeta
Published: June 2012

Background: High-risk HPVs such as HPV-16 have been implicated in the pathogenesis of cervical cancer and its premalignant lesions. Prophylactic vaccines derived from the noninfectious protein coat of HPV 16 and 18 are available commercially. However, therapeutic vaccines capable of eliminating HPV-infected cells and clearing HPV-associated tumors are not available. CTLs specific for E6 and E7 act as desirable immune effectors in recognizing and destroying HPV-infected cells and therefore HPV 16, E6, and E7 proteins pose as logical targets for immunotherapy against cervical cancer.

Objective: To develop vaccine strategies which would have both prophylactic and therapeutic potential against HPV16.

Methods: Software predicted synthetic CTL epitope dominant peptide from HPV-16, L1, L2, E6, and E7 region was synthesized (48mer) and its therapeutic vaccine potential evaluated using different adjuvants.

For chimeric VLPs, DNA was isolated from HPV-16-positive cervical cancer, cloning of L1 and E7 was done in appropriate vector, recombinant protein expressed and purified. In vitro assembly of chimeric virus-like particles (CVLPs) done. Immune response to peptide and CVLPs was measured by T cell proliferation assay, cytokine ELISA, cytotoxicity measured using LDH assay, and in vivo tumor induction (using TC-1 cells) and regression analysis done in C57BL/6J mice.

Results: Subcutaneous injection with peptide along with different adjuvants (mycobacterium Mw, alum, PLGA microspheres) enchanced serum IgG levels, showed lymphocyte proliferation, generated peptide-specific CTL-mediated cytotoxic secretion of different cytokines. Regression of tumors on in vivo challenge to TC-1 cells in C57BL6 mice was observed. Among adjuvants, peptide encapsulated in PLGA microspheres showed the best response.

CVLPs showed lymphoproliferative response and CTL generation in vitro against E7 protein and essentially showed Th-1 response. Antitumor efficacy to TC-1 cells induced tumors in C57BL/6 mice was also seen. Seroreactivity of young women with persistent HPV16 infection showed that CVLPs detected neutralizing antibodies against L1 capsid protein. Antibodies against L1 capsid protein were able to inhibit hemaglutination.

Conclusion: The above study has provided a basis for rational design of peptide-based vaccine and protein-based chimeric vaccine for controlling HPV-16 infection and its associated tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr B11.
Abstract A112: Postoperative prognostic predictors of pancreatic ductal adenocarcinoma: Clinical analysis and immunoprofile on tissue microarrays
Authors: Park Joo Kyung , Lee Se Hoon , Ryu Ji Kon , Kim Yong-Tae , Yoon Yong Bum , Kim Min A
Published: June 2012

Background: The most of pancreatic ductal adenocarcinomas metastasize even after curative resection. Our goals were to investigate the important factors affecting metastasis and overall survival. Patients and methods: We studied 88 PDACs with R0 resection and evaluated immunohistochemical markers on tissue microarrays to assess the expression levels of the following: EGFR, amphiregulin, VEGF, p-c-met, MMP2, MMP7, MMP9, CXCR3 and CXCR4.

Results: The median OS in patients who had positive vs. negative expression of AREG and MMP9 were 25 vs. 16mo and 24 vs. 13mo respectively (p=0.03, p=0.006). However, the median OS in patients with positive vs. negative expression of MMP2 was 22 vs. 37mo (p=0.04). Adjuvant treatment, postoperative decrement of CA 19–9, angiolymphatic invasion, AREG and MMP2 were independent prognostic factors affecting OS in multivariate analysis. Immunoprofiles revealed that patients with positive expression of p-c-met or VEGF had significantly shorter distant metastasis free survival.

Conclusions: Immunoprofiles revealed the groups with unfavorable tumor biology: negative expression of AREG and positive expression of MMP2. Also, high immunoreactivity of p-c-met or VEGF can be considered as indicators of early distant organ metastasis. These results may give us useful insights in choosing adjuvant treatment modalities and understanding the patterns of PDAC dissemination.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A112.
Abstract A29: The TMPRSS2:ERG gene fusion, ERG expression and prostate cancer outcomes: A cohort study and meta-analysis
Authors: Graff Rebecca E. , Ligon Azra H. , Suppan Catherine , Flavin Richard , Sesso Howard D. , Rider Jennifer R. , Sweeney Christopher , Stampfer Meir , Fiorentino Michelangelo , Kantoff Philip W. , Sanda Martin , Pettersson Andreas , Giovannucci Edward , Ding Eric L. , Loda Massimo , Mucci Lorelei A. , Bauer Scott R. , Pitt Michael , Lis Rosina T. , Stack Edward C. , Martin Neil E. , Kunz Lauren , Penney Kathryn
Published: June 2012

Background: The TMPRSS2:ERG gene fusion is a common genomic abnormality in prostate cancer that has been studied as a possible biomarker of prognosis.

Methods: We undertook a prospective cohort study and meta-analysis to evaluate whether TMPRSS2:ERG is associated with more aggressive prostate cancers. The cohort consisted of 1,052 men with prostate cancer treated by radical prostatectomy between 1982 and 2005 nested within the Physicians' Health Study and Health Professionals Follow-Up Study. We identified presence of the fusion by immunohistochemical assessment of ERG protein expression. We used Cox proportional hazards models for associations of the fusion with biochemical recurrence and lethal prostate cancer. The meta-analysis included 6,448 subjects with prostate cancer from 43 studies (including our cohort) published since 2005. Studies characterized presence of the fusion by fluorescence in situ hybridization, polymerase chain reaction, or immunohistochemistry.

Results: During a median follow-up of 12.5 years, 245 men in the cohort experienced biochemical recurrence, and 95 developed lethal disease (distant metastases or cancer-specific mortality). Men whose tumors harbored the fusion were more likely to be diagnosed at a higher stage (p=0.02). There was no association, however, between the fusion and Gleason score (Gleason 8–10 vs. 2–6; p=0.45), biochemical recurrence (HR: 0.93; 95% CI: 0.72–1.20), and lethal disease (HR: 0.81; 95% CI: 0.54–1.22). For men treated with radical prostatectomy, the meta-analysis yielded similar results. Fusion status was associated with higher stage at diagnosis (RR: 1.19; 95% CI: 1.11–1.28), but not with Gleason score (RR: 0.91; 95% CI: 0.76–1.10), biochemical recurrence (RR: 1.01; 95% CI: 0.84–1.22) or lethal disease (RR: 0.93; 95% CI: 0.44–1.99).

Conclusions: The results suggest that TMPRSS2:ERG fusion status and ERG expression are associated with higher stage at diagnosis but are not strong predictors of Gleason score, biochemical recurrence or cancer-specific death among men with prostate cancer treated with radical prostatectomy.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A29.
Abstract A3: Premenopausal serum androgens and breast cancer risk: A nested case-control study
Authors: Zeleniuch-Jacquotte Anne , Koenig Karen L. , Afanasyeva Yelena , Kaaks Rudolf , Rinaldi Sabina , Scarmo Stephanie , Liu Mengling , Arslan Alan A. , Toniolo Paolo , Shore Roy E.
Published: June 2012

Introduction: Prospective epidemiologic studies have consistently shown that levels of circulating androgens in postmenopausal women are positively associated with breast cancer risk. However, data in premenopausal women are limited.

Methods: A case-control study nested within a prospective cohort, the NYU Women's Health Study, was conducted. A total of 356 cases (276 invasive and 80 in situ) and 683 individually-matched controls (1:2 matching) were included. Matching variables included age and date of blood donation, as well as phase and day of menstrual cycle. Testosterone, androstenedione, dehydroandrosterone sulfate (DHEAS), and sex hormone-binding globulin (SHBG) were measured using direct radioimmunoassays. Free testosterone was calculated. Samples from a second blood donation at a median of 2 years after the first blood donation were also analyzed for 138 cases and 268 controls.

Results: Premenopausal serum testosterone and free testosterone concentrations were positively associated with subsequent breast cancer risk. In models adjusted for known risk factors of breast cancer (BMI, age at menarche, family history of breast cancer, parity/age at first birth, and history of breast biopsy), the odds ratios for increasing quintiles of testosterone were 1.0 (reference), 1.5 (95% confidence interval (CI), 0.9–2.3), 1.2 (95% CI, 0.7–1.9), 1.4 (95% CI, 0.9–2.3) and 1.8 (95% CI, 1.1–2.9) with the P value for trend of 0.04, and for free testosterone were 1.0 (reference), 1.2 (95% CI, 0.7–1.8), 1.5 (95% CI, 0.9–2.3), 1.5 (95% CI, 0.9–2.3), and 1.8 (95% CI, 1.1–2.8) with a P value for trend of 0.01). A marginally significant positive association was observed with androstenedione (p = 0.07), but no association with DHEAS or SHBG. Results were consistent in analyses stratified by tumor type (invasive, in situ), estrogen receptor status, age at blood donation, and menopausal status at diagnosis. Intra-class correlation coefficients (ICCs) for measurements of serial annual blood donations from the same individual were greater than 0.7 for all biomarkers except for androstenedione (0.57 in controls).

Conclusions: Premenopausal concentrations of testosterone and free testosterone are positively associated with breast cancer risk. Results from other prospective studies are consistent with our results. Testosterone and free testosterone are also highly reliable (i.e. a single measurement is reflective of a woman's average level over time). Future studies should examine the contribution of including testosterone and free testosterone in breast cancer risk prediction models for women between the ages of 40 and 50.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A3.
Abstract A39: EGCG, a green tea polyphenol, can reverse methylation related silencing of genes in human colon carcinomas
Authors: Morris Jay , Moseley Vondina R. , Coleman Katie , Wargovich Michael
Published: June 2012

Silencing of regulatory genes through hypermethylation of CpG islands is an important mechanism in tumorigenesis. In colon cancer, RXRα, an important dimerization partner with other nuclear transcription factors, is silenced through this mechanism. Previous studies from our laboratory have shown that ApcMin/+ mice treated with the carcinogen azoxymethane (AOM) will develop colonic tumors but when treated with green tea a reduction in tumor numbers was found. We found that colon tumors had lower expression of RXR protein but expression levels were restored by treatment with green tea. We also found that the degree of promoter methylation of the RXR gene was reduced. To translate these findings to human colon cancer we treated CpG Island Methylator Phenotype sensitive and insensitive (CIMP+ & CIMP-) human colon cancer cell lines with epigallocatechin gallate (EGCG - major polyphenolic compound in green tea). We hypothesized that CIMP+ cell lines which epigenetically silence key regulatory genes would demonstrate silencing of RXRα and that EGCG would restore its expression. To test this we used the following human colon cancer cell lines: HCT116, SW48, HCT15 - CIMP+; HT29, SW480, SW620 - CIMP- and IEC-6 - normal control. We found EGCG to restore RXR activity levels in the CIMP+ lines, in a dose dependent manner (0, 50, 100 & 150 μM EGCG was tested for 48 and 72 hour durations). EGCG also reduced RXRα promoter methylation in one CpG island from a CIMP+ cell line compared to a CIMP-line. We found that EGCG produced methylation changes in several other colon cancer related genes but did not cause a decrease in global methylation. Numerous epidemiological reports have shown the benefits of green tea consumption in reducing colon cancer risk but to date no studies have shown that some of the risk reduction may be related to the epigenetic regulation of key genes by constituent tea polyphenols. Our results here show that EGCG, a common tea polyphenolic compound, can modulate the reversal of gene-silencing involved colon carcinogenesis and maybe a possible avenue for colon cancer treatment. Supported by USPHS grant CA96694 from the National Cancer Institute.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A39.
Abstract A40: Epigenetic modification of human colon cancer by the green tea polyphenol EGCG
Authors: Moseley Vondina R. , Morris Jay , Wargovich Michael J.
Published: June 2012

Silencing of regulatory genes through hypermethylation of CpG islands is an important mechanism in tumorigenesis of numerous cancers. We have previously shown that Retinoid X Receptor alpha (RXRα) is silenced in tumors of the colon cancer AOM-APC/min+ mouse model. Upon treatment with green tea, RXRα expression was restored and intestinal tumorigenesis was inhibited. We examined human colonic tumor microarrays by immunohistochemcial staining and found a marked decrease in RXR expression in tumor tissue compared to normal matched tissues, inversely β-Catenin levels increased. To determine how RXRα loss is reversed in human cancers by green tea, we treated HT-29 (methylation insensitive) and HCT116 (methylation sensitive) human colon cancer cell lines with different concentrations of Epigallocatechin gallate (EGCG - major polyphenolic compound in green tea). We found by western blotting nuclear protein fractions that EGCG can restore RXRα levels in HCT116 cells in a dose dependant manner. Using these same lysates, we probed for presence of the most common DNA Methyltransferases (DNMTs) and Histone Deacetylases (HDACs). We found that expression of DNMTs as well as HDACs was inhibited in a dose dependent manner following treatment with EGCG. Additionally we examined by real time PCR, the message levels of DNMTs in cells treated with EGCG to determine if they correlate with the observed downregulation in protein expression. We can conclude that the silencing of RXRα may be due in part to by repressing effects of EGCG on DNMT as well as HDAC activity. Our results here show that EGCG, a common dietary compound, can modulate the reversal of gene-silencing involved colon carcinogenesis and maybe a possible avenue for colon cancer therapy and demonstrates be one potential mechanism of cancer chemoprevention in green tea that outlines a new epigenetic pathway.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A40.
Abstract A94: ABO blood group and risk of renal cell cancer
Authors: Joh Hee-Kyung , Cho Eunyoung , Choueiri Toni K.
Published: June 2012

Background: The genetic determinants of sporadic renal cell cancer (RCC) are largely unknown. Previous studies have suggested associations between the ABO blood group and risk of various cancers, however, its relationship to RCC remains unclear.

Methods: We prospectively evaluated the association between the ABO blood group and risk of RCC in two large independent cohorts of women (the Nurses' Health Study) and men (the Health Professionals Follow-up Study) from 1996 to 2008. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models with adjustment for other risk factors for RCC including obesity, smoking, and hypertension. All statistical tests were two-sided.

Results: During 12 years of follow-up of 77,242 women and 29,548 men, 163 cases of incident RCC were documented in women and 84 cases in men. After multivariate adjustment, non-O blood group (combined group of A, AB, and B) was associated with a 1.5-fold elevated risk of RCC (95% CI 1.09–2.09) than O blood group in women. In contrast, no significant associations were observed between the ABO blood group and risk of RCC in men. The associations between the ABO blood group and RCC were consistent across strata of known risk factors including obesity, smoking status, and history of hypertension (Pinteraction ≥ .58) in both cohorts.

Conclusion: We show for the first time that non-O blood group is significantly associated with a higher risk of RCC compared with blood group O in women. Further studies that elucidate the biological mechanisms underlying this association are warranted.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):A94.
Abstract B22: Fatigue among long-term survivors of breast cancer: A prospective cohort study with longitudinal follow-up
Authors: Chen Wendy Y. , Holmes Michelle D. , Hankinson Susan E.
Published: June 2012

Background: Fatigue is a common side effect of cancer treatment, but the longer terms effects of cancer diagnosis and treatment on fatigue are not well quantified. Study population: Participants from the prospective Nurses' Health Study who completed the Medical Outcomes Short-Form-36 (SF36) in 1992, 1996, and 2000. Outcomes: The 5-item Fatigue subscale from the SF36. A score of ≤ 50 is considered to represent fatigue:

Results: 46,851 women without a history of cancer, 1015 women diagnosed with invasive breast cancer between 1984 and 1991, and 187 women diagnosed with in situ breast cancer between 1984 and 1991 were included in this analysis. All fatigue assessments were performed at least one year after diagnosis. Using the three time points, several fatigue trajectories were investigated including: persistently fatigued at all three time points, persistently non-fatigued at all time points, and developing fatigue over time. In age-adjusted analyses, the frequencies of the different fatigue trajectories were similar across the three groups: cancer free women, breast cancer survivors with invasive breast cancer, and survivors with in situ disease. That is, the chances of being persistently fatigued, persistently non-fatigued, or developing fatigue was similar across all three groups (p>0.09). Instead, the strongest predictor of fatigue trajectories was age. The prevalence of persistent fatigue and persistent non-fatigue varied strongly with age with a U-shaped curve (p<0.01). Specifically, the women aged 55–59.9 and 60–64.9 (when categorizing participants by 5 year age groups) had the lowest incidence of persistent fatigue and highest incidence of non-fatigue compared to older (65+) or younger women (<55).

Conclusions: After a cancer diagnosis, the prevalence of persistent fatigue or developing fatigue is similar comparing cancer-free women compared to breast cancer survivors. Self-assessments of fatigue appear to be more strongly related to age. Age needs to be carefully considered in all fatigue analyses and would provide a useful way to target interventions to improve fatigue.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B22.
Abstract B36: Respiratory symptoms after smoking cessation among college students
Authors: Calabro Karen S. , Prokhorov Alexander V.
Published: June 2012

Introduction: Data about respiratory symptoms and lung function are available for middle-aged adults post-cessation. Similar evidence is lacking for those aged 18 to 24 years. This study addresses that gap. Procedures: This report is a secondary analysis of data derived from two randomized controlled smoking cessation trials among a subset of 18- to 24-year-old college students. Data from both studies were combined regardless of treatment condition. Some participants received an active intervention while controls were provided with self-help smoking materials. Self-reported respiratory symptoms were longitudinally analyzed in 273 quitters. The change in respiratory symptoms was calculated by subtracting the final scores from those at baseline.

Summary of Data: The respiratory symptoms of continued smokers were compared to the quitters at the final visit using t-tests. Significant improvements in respiratory symptoms were found among quitters for morning cough, (p =.002) daytime cough, (p =.007), and chest pain (p =.007).

Statement of Conclusions: Young individuals rarely respond to quit-smoking motivation based on long-term health consequences, such as risk of tobacco-attributable cancers. A more appropriate motivational strategy for young adults appears to be emphasizing the existing respiratory symptoms caused by smoking. Clinicians are encouraged to detect and discuss respiratory symptoms with their young tobacco-using patients as a part of smoking cessation counseling and treatment. Highlighting post-cessation reduction in these symptoms is likely to reinforce continued abstinence.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B36.
Abstract B60: Overexpression of VCAM-1 promotes tumor progression and drug resistance in breast cancer
Authors: Kuo Tzu-Lei , Hou Ming-Feng , Cheng Kuang-hung
Published: June 2012

VCAM-1 (CD106) is a transmembrane glycoprotein that is involved in many pathological inflammatory processes. VCAM-1 plays an important role in leukocyte adhesion, leukocyte transendothelial migration and cell activation by binding to integrin VLA-1 (α4β1). In our preliminary data, we first identified that VCAM-1 expression can be induced in many breast cancer epithelial cells by cytokine stimulation and directly correlated with breast tumor progression; however, its mechanism of action in tumor biology remains unknown. Here, we describe the establishment and use of breast cancer cell line model systems to dissect the functional roles of VCAM-1 activation in the manifestation of malignant phenotypes of human breast cancer. We show that VCAM-1 overexpression in the NMuMG breast epithelial cells increase cell adhesion and motility rates and promote chemoresistance to doxorubicin and cisplatin in vitro. Conversely, in an established metastatic breast cancer cell line, MDAMB231, we confirmed that the knockdown of endogenous VCAM-1 expression by small interfering RNA (SiRNA) reduced cell proliferation and inhibited TGFb1 or IL6 mediated cell migration. Furthermore, we also demonstrated that knockdown of endogenous VCAM-1 expression in MDAMB231 cells reduced the tumor formation in an SCID xenograft mouse model. In conclusion, our findings uncover the critical role of VCAM-1 activation in facilitating breast cancer progression by enhancing the malignant properties of breast cancer cells and suggest that targeting of VCAM-1 induced pathways is an attractive strategy for therapeutic intervention.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B60.
Abstract B67: Curcumin induces stabilization of Nrf2 protein by decreasing the activity of Cullin3-Rbx1 E3 ubiquitin ligase
Authors: Shin Jun-Wan , Surh Young-Joon
Published: June 2012

Curcumin, the yellow pigment of tumeric (Curcuma longa L., Zingiberaceae), is one of the most widely used spices in the East Asia. Curcumin has been shown to possess anti-inflammatory, antioxidative and chemopreventive effects. Although a growing body of evidence suggests that the chemopreventive potential of curcumin depends partly on its ability to induce cytoprotective proteins through the activation of nuclear factor erythroid-related factor-2 (Nrf2), the molecular mechanisms remain elusive. The present study was aimed to elucidate the mechanisms underlying the activation of Nrf2 and induction of cytoprotective gene expression by curcumin. Incubation of mouse epidermal (JB6) cells with curcumin resulted in the induction of heme oxygenase-1 (HO-1) and NAD(P)H oxidoreductase 1 (NQO1) at both mRNA and protein levels. Curcumin-induced expression of HO-1 and NQO1 was abrogated in cells transiently transfected with Nrf2 siRNA. Furthermore, embryo fibroblasts from Nrf2 knock-out mice were not responsive to curcumin, compared with those from wild-type animals, in terms of inducing HO-1 and NQO1 expression. While curcumin treatment increased protein expression of Nrf2, it failed to alter the steady-state level of the Nrf2 mRNA transcript, suggesting that protein stabilization might be involved in curcumin-induced Nrf2 accumulation. Treatment of JB6 cells with curcumin did stabilize Nrf2 by inhibiting ubiquitination and subsequent 26S proteasomal degradation of Nrf2. Kelch-like ECH-associated protein-1 (Keap1), a substrate adaptor of Cullin3-Rbx1 E3 ubiquitin ligase complex, has several reactive cysteine residues, and modification of these cysteine residues has been proposed as a molecular mechanism underlying oxidative and electrophilic stress-induced activation of Nrf2. The thiol-reducing agent dithiothreitol abrogated curcumin-induced accumulation of Nrf2 and expression of cytoprotective proteins. In addition, tetrahydrocurcumin, a non-electrophilic analogue of curcumin that lacks the α,β-unsaturated carbonyl group, failed to induce cytoprotective protein expression as well as Nrf2 nuclear translocation, indicative of a pivotal role of cysteine residues of Keap1 in curcumin-induced Nrf2 activation. Cells transfected with a mutant Keap1 protein in which cysteine 151 is replaced by serine exhibited reduction in curcumin-induced Nrf2 activation. Although curcumin did not cause dissociation of Cullin3-Rbx1 E3 ubiquitin ligase complex components, it increased interaction of Nrf2 with the Keap1. Thus, it is likely that curcumin inhibits the ability of the Cullin3-Rbx1 E3 ubiquitin ligase to target Nrf2 for ubiquitination by modifying Keap1 Cys 151 residue. This may change the conformation of the complex and saturates the binding capacity of Keap1 to Nrf2, facilitating nuclear translocation of Nrf2.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B67.
Abstract B69: Cellular neutral lipid content is a novel biomarker of cancer preventive activity
Authors: Uray Ivan P. , Bissonnette Reid , Brown Powel H.
Published: June 2012

Introduction: Commonly used biomarkers to assess the cancer preventive activity of cancer preventive agents include markers of cell proliferation or apoptosis. However, the expression of proliferation or apoptosis markers is highly variable, and measurement is often done using semi-quantitative assays. In addition, cancer preventive agents may act through mechanisms that do not depend on proliferation or apoptosis. Therefore, identification of new biomarkers indicative of the cancer preventive activity of chemopreventive agents is essential for the development of new cancer preventive drugs.

Methods: We applied high-content microscopic analysis to assess the phenotypic changes occurring in normal mammary epithelial cells (HMECs) after treatment with cancer preventive drugs by measuring cell proliferation, DNA and neutral lipid content and localization, as well as cell cycle distribution of the cells. Gene specific knock-down was achieved by transfections with siRNA duplexes. Measurement of transcript levels was performed using quantitative real-time RT-PCR.

Results: Multiparametric analysis of high-throughput image based studies have revealed that anti-proliferative activity of cancer preventive rexinoids is associated with increased formation of cytoplasmic lipid droplets.

Accumulation of cytoplasmic neutral lipids was restricted to cell types that undergo significant growth suppression by bexarotene (HMECs, SUM225, and ZR75.1), but not observed in retinoid-resistant cells (MCF10A, HCC1937, and HCC1143). Other growth suppressive drugs including the kinase inhibitor lapatinib, vitamin D, and certain natural compounds, including epicatechine monogallate, duartin, actinonin and homoisoflavonoids, were also found to increase cellular neutral lipid content in breast cells. The addition of external fatty acids, such as oleic and palmitoleic acids did not result in dose-dependent growth suppression or accumulation of neutral esterified lipid droplets. Lipid accumulation and growth suppression were associated with the up-regulation of genes involved in regulating the formation of neutral lipids, triglycerides and phospholipids, but not genes involved in de novo fatty acid synthesis. Conversely, knock-down of key proteins controlling cellular triglyceride synthesis and storage, diacylglycerol acyltransferase 1 (DGAT1) and adipophyllin (Adfp) increased cell proliferation whereas their induction was associated with growth suppression in HMECs.

Conclusion: These results suggest that increased accumulation of cellular triglycerides may be a useful biomarker to assess the preventive effect of putative cancer preventive agents. These results support the systematic testing of cellular neutral lipid levels in preclinical and clinical models testing novel chemopreventive agents.

This work was supported by the grant RO1 CA 78480 (to P.H.B.).

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B69.
Abstract B70: Inhibition of nuclear bile acid receptor FXR as a target in prevention of esophageal adenocarcinoma
Authors: Guan Baoxiang , Li Hao , Yang Zhengduo , Hoque Ashraful , Xu Xiaochun
Published: June 2012

Incidence of esophageal adenocarcinoma is increasing in the United States and other Western countries. Frequent gastroesophageal reflux or gastroesophageal reflux disease, resulting in Barrett esophagus, may be responsible for the increase. The main function of bile acid is to facilitate the formation of micelles for promotion of the processing and absorption of dietary fat. As surfactants or detergents, bile acids are potentially toxic to the cells, so their concentrations in the small intestine are tightly regulated. However, patients with frequent gastroesophageal reflux will have reflux damage caused by acid and bile acid-containing juice in the distal esophagus, with the result that normal squamous cells around the gastroesophageal junction will change to a new cell phenotype (incomplete intestinal metaplasia), because this type of cell is more resistant to acid and bile-caused injuries; therefore, Barrett esophagus is formed. This study aimed to determine the tumor-promoting effects of bile acid on esophageal cancer cells and the underlying molecular mechanisms. The data showed that different bile acids (i.e., chenodeoxycholic acid, deoxycholic acid, and lithocholic acid) induced COX-2 but inhibited RAR-β2 expression through farnesoid X receptor (FXR) expression in esophageal cancer cell lines. FXR is a nuclear receptor for bile acids functioning as a signaling molecule in the liver and the intestines and frequent gastroesophageal reflux induces FXR expression in esophageal cells. Indeed, the ex vivo data demonstrated that FXR was highly expressed in esophageal adenocarcinoma (81%) tissues and was associated with reduced RAR-β2 expression. Knockdown of FXR expression using FXR shRNA antagonized the effects of bile acid in gene expression and suppressed tumor cell viability in vitro and in nude mouse xenografts. Moreover, guggulsterone, a FXR inhibitor, was able to reduce the viability of esophageal cancer cells in time- and dose-dependent manner in vitro. Apoptosis induced by guggulsterone was through activation of caspase 8, 9, and 3. In conclusion, suppression of FXR expression using FXR shRNA or its inhibitor guggulsterone was able to suppress tumor cell growth in vitro and in vivo and induce apoptosis in vitro. This study demonstrated that inhibition of FXR could be further evaluated as a target in prevention of esophageal adenocarcinoma.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B70.
Abstract B79: Evaluation of active hexose correlated compound (AHCC) for the prevention or delay of tumor growth in human cervical cancer xenograft model
Authors: Smith Judith A. , Mathew Lata , Gaikwad Anjali , Jaffari Mona , Julius Jusitn M. , Julius Jusitn M. , Frumovitz Michael , Dalrymple John L.
Published: June 2012

Purpose: Active hexose correlated compound (AHCC) is a mixture of polysaccharides, amino acids, lipids and minerals extracted from the culture of the basidiomycete mushroom Lentinula edodes (shiitake) that has been proposed to have many health benefits including both immunomodulatory and anti-tumor effects. In clinical studies AHCC has demonstrated numerous immunomodulating and potential restorative effects on natural killer (NK) cells, macrophages and cytokines. The objectives of this study were to evaluate if daily treatment with AHCC would eradicate human papillomavirus (HPV) 16/18 expression and prevent or delay cervical tumor growth using human xenograft mouse model.

Methods: Selected cervical cancer cells, SiHa (HPV 16/18 positive), and C-33A (HPV negative) were treated in vitro with a single dose AHCC 0.42 mg/mL and incubated for 72 hours. In the second study AHCC dose was repeated once every 24 hours for total of seven days. This was followed by a three arm in vivo study in two xenograft cervical cancer mouse models, SiHa (HPV 16/18 positive), and C-33A (HPV negative), in which each cell line had ten mice for the treatment arm, vehicle control arm and no treatment arm. Mice in the treatment arm received 50 mg/kg AHCC in 0.25 mL of sterile water every day for seven days before the injection of the tumor cells and until the completion of the study. Tumors were measured three times per week. After 90 days of treatment, there was a 30 day observation period to evaluate the potential for recurrence of the HPV infection and the impact on tumor growth. At the end of the study, tumors were extracted and RT-PCR was completed on DNA samples from extracted protein to evaluate the HPV expression.

Results: In vitro treatment with a single dose of AHCC for 72 hour incubation suppressed HPV expression in the first 24 hours but then HPV expression recovered by 48 hours. However, with continuous in vitro exposure, sustained HPV suppression was observed. In the in vivo animal studies, expression of HPV was eradicated with once daily AHCC dosing for 90 days and no detection of HPV expression was sustained after 30 days off treatment. In addition, AHCC daily treatment was associated with a 15.9% decrease in SiHa (HPV 16/18 positive) tumor growth compared to the untreated control (P< 0.05). AHCC did impact the growth rate of the C-33A (HPV negative) tumors.

Conclusion: In conclusion, these data suggest daily dosing of AHCC will eradicate HPV 16/18 infections and may have a role in the prevention of HPV-related cervical cancer. Furthermore, there is a potential for the addition of AHCC to primary treatment regimens for cervical cancer, which may potentially improve response rates and prevent recurrence. A confirmatory pilot study in HPV positive women is underway.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B79.
Abstract B83: Isoflavones from phytoestrogens and cervical cancer risk: A nested case-control study
Authors: Ju Woong , Kim Seung Cheol , Kim Nam Hee , Kim Yun Hwan
Published: June 2012

Objective: The effect of soybean products in cervical cancer risk has not been investigated yet. To examine the association between soybean product intake and cervical cancer risk, we measured phytoestrogen biological markers in cervical cancer patients and non-cancer control patients.

Methods: Among patients visit Ewha womans university hospital between October 2007 and October 2010, 143 cases and 143 matched controls as same age distribution were enrolled. The concentrations of the four biomarkers in the plasma samples were measured using time-resolved fluoro-immunoassay. Dose-response relationship was analyzed with restricted cubic spline method. Conditional and unconditional logistic regression models were used to compute the odds ratio (OR) and 95% confidence intervals (CI).

Results: There are linear relationships between two isoflavones concentrations (daidzein, equol) and cervical cancer risk. As daidzein concentration increased by 100 nmol/L, cervical cancer risk significantly increases by 41.4%. (P=0.028) Compared with the reference group, cervical cancer risk increased significantly in higher concentration of daidzein(P=0.04), genistein(3rd and 4th quantile, P=0.03), enterolactone(3rd quantile, P=0.003).

Conclusions: Serum concentrations of daidzein, genistein, and enterolactone were siginificantly associated with a increased risk for cervical cancer.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B83.
Abstract B87: Analgesics use increase the risk of renal cell carcinoma (RCC): Results from a large up-to-date meta-analysis
Authors: Choueiri Toni K. , Je Youjin , Cho Eunyoung
Published: June 2012

Introduction: Analgesics have been linked to an increased risk of developing renal cell carcinoma (RCC), but the evidence is mixed. Using a meta-analysis design of all available studies, we investigated the association between analgesic use and RCC risk.

Methods: We searched the MEDLINE database to identify eligible case-control or cohort studies published in English from 1966 to July 1, 2011 for 3 categories of analgesics: acetaminophen, aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs). Study-specific effect estimates were pooled to compute an overall relative risk (RR) and its 95% confidence interval (CI), using a random effects model, for each category of the analgesics. Analyses were conducted according to regular/any use and high dose or long-duration of use, separately.

Results: We identified 18 studies (12 for acetaminophen, 12 for aspirin, and 5 for other NSAIDs) that were performed in 6 countries. Regular/any use of acetaminophen and other NSAIDs were each associated with an increased risk of RCC: pooled RR, 1.33 (95% CI 1.18–1.49) for acetaminophen and 1.26 (95% CI, 1.09–1.44) for other NSAIDs, respectively. For use of aspirin, we found no significant increased risk (pooled RR, 1.14 [95% CI, 0.98–1.33]). Similar risk trends were seen with high dose of analgesics intake. No significant difference in associations was found by study design (case-control vs. cohort), type of controls in case-control study (population based vs. hospital based), outcome (RCC vs. kidney cancer), and gender (male vs. female). There was no indication of publication bias for the 3 analgesics. Conclusions: In this meta-analysis of analgesics use and RCC risk, we found that use of acetaminophen and non-aspirin NSAIDs was associated with a significant increased risk of developing RCC.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):B87.
Abstract ED04-01: Breast cancer chemoprevention
Authors: Cuzick Jack
Published: June 2012

There is much activity on this front. For the selective estrogen receptor modifiers (SERMs), there is long term data on raloxifene and recent data on new SERMs – (lasofoxilene and arzoxifene). An individual patient overview will be given to update both short-term (< 5 yrs) and long term (5–10 y) efforts.

Results from the MAP3 trial on the aromatase inhibitor exemestane has recently been reported and additional long term data on prevention of contralateral tumours in the adjuvant ATAC trial using anastrozole will be reviewed, as well as the current situation of the IBIS II prevention trial with anastrozole.

There is much interest in nonhormonal agents for breast cancer prevention including metformin, bisphosphonates, aspirin, and the NSAIDs, which will all be reviewed.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):ED04-01.
Abstract PL02-02: Energy balance and cancer prevention: Lessons learned from clinical research
Authors: Goodwin Pamela J.
Published: June 2012

Energy balance is associated with risk of development of many common cancers, and with clinical outcomes after cancer diagnosis in several solid tumors. Higher BMI leads to an increased risk of most solid tumors and hematologic malignancies. Exceptions in both sexes include lung and esophageal cancer; in women they also include premenopausal breast cancer (Renehan et al Lancet 2008). Physical inactivity has been convincingly or probably associated with increased risk of cancer of the breast, colon and endometrial cancer and possibly associated with an increased risk of lung, prostate and ovarian cancers; it has been estimated risk of these cancers might be reduced by 20–30% in active individuals (Friedenreich C et al Eur J Cancer 2010). Furthermore, observational data suggest that cancer risk may be reduced in obese individuals who undergo bariatric surgery (Renehan Lancet Oncology 2009) and that risk of obesity-related cancers (breast, colon, endometrial, any obesity associated cancer) is reduced in individuals reported an intentional weight loss of 20 pounds or more. Similar associations have been reported in patients diagnosed with several common types of cancer. For example, higher BMI has been convincingly associated with poor breast cancer outcomes; meta-analyses suggest relative risk of recurrence or death is increased by 25–40% in obese women. Evidence is less convincing for colorectal cancer; obesity may be associated with prostate cancer having more aggressive characteristics. Higher levels of physical activity pre and/or post diagnosis have been associated with improved outcomes in breast and colorectal cancer. One randomized trial involving 2437 early stage breast cancer patients reported improved relapse free survival (HR 0.96, 95%CI 0.60–0.98) in those randomized to a reduced fat diet (associated with modest weight loss) versus controls. A second RCT in breast cancer survivors failed to identify a prognostic effect of a more complex dietary intervention that lowered fat intake but was not associated with weight loss. Intervention studies have convincingly demonstrated that modification of energy balance (physical activity, dietary change, weight loss) in cancer patients is feasible, particularly in those with breast cancer, but confirmation of beneficial effects on cancer outcomes is lacking. Potential physiologic mediators of prognostic effects of energy balance include members of the insulin/insulin-like growth factor pathway, inflammation, adipocytokines and sex hormones; it is likely the relative importance of these factors varies across tumor types. Large scale intervention studies targeting energy balance, its components (e.g. physical activity) and/or key physiologic mediators are needed to provide high level evidence regarding benefits of modifying energy balance, or its physiologic mediators. One study targeting insulin (MA32) is underway in breast cancer survivors; others have been proposed.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):PL02-02.
Abstract PL03-02: Using technology for early cancer prevention among youth
Authors: Prokhorov Alexander V.
Published: June 2012

Computer and internet technology is becoming widely available and heavily used by youth in the United States. Today's cancer prevention programs geared towards young individuals ought to consider technology as a cost-effective and attractive channel of information delivery. Our investigative team has implemented several technology-assisted early cancer prevention programs aimed at smoking prevention and cessation. Our first large-scale study that used computer technology (CD-ROM) was Project ASPIRE. This interactive multimedia program tailored to the needs of individual user was tested in 16 Houston-area high schools. At 18-month smoking initiation rates were significantly lower in the ASPIRE condition compared to controls (N=1,160; 1.9% vs. 5.9%, p<.05). The additive effects of multiple smoking initiation risks were examined using a cumulative model. As the level of risk increased smoking initiation increased significantly in the control group (2.7% to 17.2%, p<.001), while remaining low and stable in the intervention group. Currently, ASPIRE is being disseminated online among thousands of users in 21 states. Smoking cessation programs for community college students (laptop-assisted Project Look at Your Health) and university students (internet-based Project SUCCESS) were tested in two randomized controlled trials. In Project Look at Your Health (N=326), the cotinine-validated smoking quit rates at 10-month follow-up were 17.2% and 10.2% in the experimental group and standard-care group, respectively (p<.06). Statistically significant results were achieved in the updated and improved online version of the intervention used in Project SUCCESS. At 12 months, (N=236), the intent-to-treat analysis revealed the quit rates of 20% in the experimental condition versus 10% in the standard care, (p<.01). Currently, we are designing the 3rd version of the smoking cessation intervention for college students that systematically addresses depressive symptoms and alcohol use. Our investigative team is among the leaders designing the cutting-edge educational tools for youth in the form of video games. Our DOD-funded prototype tobacco prevention and cessation video game, Escape with Your Life, is using a hospital metaphor in which participants learn about the dangers of tobacco use while visiting various rooms (surgery, patient records, waste disposal, accounting, etc.). This novel educational tool is richly equipped with animations, videos, and interactive features. Escape with Your Life has produced promising preliminary results. Currently, we are in the final stages of designing a tablet computer-based smoking cessation video game for the U.S. Army service members who are at high risk for lifelong nicotine dependence and multiple tobacco-attributable cancers.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):PL03-02.