bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract B77: Pomegranate extract inhibits MMTV-Wnt-1 mammary tumor cell growth and induces apoptosis in vitro
Authors: Dai Zhaoli , Nair Vidhya , Khan Maruf , Ciolino Henry P.
Published: May 2012

In this study we report the effects of a standardized pomegranate extract (PE), as well as individual phytochemicals derived from pomegranate, on the growth of an aggressive, fast-growing mammary tumor cell line derived from the MMTV-Wnt-1 mouse (designated A4). PE caused a concentration- and time-ependent decrease in A4 cell proliferation (IC50 of approximately 25 microg/ml culture medium). PE also caused a concentration-dependent increase in cell death, with an IC50 of 50 microg/ml culture medium. PE caused an increase in caspase-3 activity in a concentration- and time-dependent manner. We also examined the effect of individual phytochemicals present in PE. Ellagic acid, luteolin, and ursolic acid inhibited the proliferation of A4 cells and induced cell death, but caffeic acid had no effect. These results indicate that PE and pomegranate phytochemicals inhibit the growth and are cytotoxic to MMTV-Wnt-1 mammary tumor cells. PE may therefore be natural and safe chemopreventive agent against breast cancer.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B77.
Abstract B78: In vitro cytotoxic and antiproliferative activitiess of marine macroalgae from Yucatan, Mexico
Authors: Moo-Puc Rosa E. , Robledo Daniel , Freile-Pelegrin Yolanda
Published: May 2012

Extracts from 27 marine algal species (14 Rhodophyta, 5 Phaeophyta and 8 Chlorophyta) from the Yucatan peninsula (Mexico) were evaluated for cytotoxic and anti-roliferative activity by 3[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and sulforhodamine B (SRB) assays, respectively. In order to determine the specificity of the cytotoxic activity on tumor cells selective index (SI) was also calculated. The following cancer cell lines were employed: normal canine kidney cells (MDCK), human laryngeal carcinoma (Hep-2), human cervix adenocarcinoma (HeLa) and human nasopharynx carcinoma (KB). The results indicated that 44 and 51% of algal species tested showed cytotoxic and anti-roliferative activity, respectively. Most of the cytotoxic extracts were species belong to Chlorophyta, Udotea flabellum and Udotea conglutinate showed the highest cytotoxic activity on all cancer cell lines. For Rhodophyta, the extract of Bryothamnion triquetrum showed an outstanding selective cytotoxicity against Hep-2 cells (CC50 8.29 µg mL−1 with SI=12.04). Two out of five species of Phaeophyta tested (Lobophora variegata and Dictyota caribaea) showed high cytotoxicity activity on KB cell line. The data show that these extracts are potential source of compounds for prevention of certain cancer diseases.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B78.
Abstract B79: Xanthohumol from hops (Humulus lupulus L.) is a novel antiandrogen
Authors: Strathmann Julia , Diel Patrick , Laudenbacher-Leschowsky Ute , Zierau Oliver , Mikros Emmanuel , Lamprinidis Giorgos , Gerhauser Clarissa
Published: May 2012

Xanthohumol (XN), a prenylated chalcone from hops, possesses a broad spectrum of chemopreventive actions, including anti-inflammatory, antioxidant, and anti-estrogenic mechanisms, and inhibits tumor growth in vitro and in vivo.

This study aimed to investigate the anti-androgenic potential of XN with regard to prostate carcinogenesis. In hormone-depleted, androgen-sensitive LNCaP human prostate cancer cells, XN at a concentration of 10 µM inhibited prostate specific antigen (PSA) secretion induced by 25 nM dihydrotestosterone (DHT) by more than 90% (p<0.001) after 24, 48 and 72 h of incubation. In a concentration range of 0.4 to 50 µM, XN dose-dependently inhibited PSA secretion (p<0.001) with a halfmaximal inhibitory concentration of 3.1 ± 0.32 µM after 48 h of incubation. Also, DHT-PSA-and insulin like growth factor (IGF-1) mRNA expression was dose-dependently inhibited by increasing XN concentrations (p<0.05), measured by quantitative RT-PCR. Western Blot analyses of cytosolic and nuclear protein lysates revealed that XN inhibited DHT-induced nuclear translocation of the androgen receptor (AR). Furthermore, in a yeast AR assay, XN inhibited AR-transcription at concentrations of 10 to 100 µM. Docking calculations of XN to the AR indicate steric interactions between the prenyl moiety of XN and Trp741, which could destabilize the AR C-terminal helix 12 and thus further explain the antagonist activity of XN.

To investigate anti-androgenic action of XN in vivo, a Hershberger assay with male orchiectomizedWistar rats was performed. Prostate and seminal vesicle weight gain was stimulated by subcutaneous application of 0.2 mg/kg body weight (bw) testosterone propionate (TP). After 12 days, no significant inhibitory effects of oral XN (10 and 30 mg/kg bw) on prostate weights was observed, whereas the anti-androgen flutamide used as a positive control inhibited the 1.2-fold induction of prostate weights by 78% (p<0.001). However, seminal vesicle weight gain induced by TP was significantly reduced by 56 and 29% by XN treatment (10 and 30 mg/kg bw), respectively, and by 92% by flutamide application. Quantitative RT-PCR analyses of prostate RNA confirmed the anti-androgenic effects of XN in vivo. XN and flutamide significantly reduced the expression of androgen-dependent target genes PSA, AR, IGF-1, prostate binding protein C3, myostatin and tyrosine aminotransferase (p<0.05).

Taken together, in the present study XN was identified as a potent novel anti-androgen, which might be of use for future prostate cancer prevention trials.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B79.
Abstract B80: Role for sphingosine kinase 1 in colon carcinogenesis
Authors: Kawamori Toshihiko , Furuya Hideki , Wada Masayuki , Bielawski Jacek , Hannun Yusuf A. , Obeid Lina M.
Published: May 2012

Colorectal cancer remains the 2nd leading cause of cancer-related deaths in the US despite recent advances in screening and therapeutic technology. Recent studies suggest that bioactive sphingolipids are key in regulating the arachidonic acid cascade of inflammation, which is significant in colon cancer pathogenesis. Sphingolipid metabolites such as ceramide, sphingosine, and sphingosine-1-phosphate (S1P) are a new class of lipid messengers that regulate cell functions. Sphingosine kinase 1 (SphK1), phosphorylates sphingosine to form S1P, is a critical regulator of sphingolipid-mediated functions, as it not only produces the pro-growth, anti-apoptotic messenger S1P, but also decreases pro-apoptotic ceramide and sphingosine. Our previous studies implicated the SphK1/S1P pathway in induction of the arachidonic acid cascade, a major inflammatory pathway involved in colon carcinogenesis (FASEB J., 20: 386–388, 2006). Then, we investigated whether the SphK1/S1P pathway is necessary for mediating carcinogenesis in vivo. We report that 89% (n=47) of human colon cancer samples stained positively for SphK1 whereas normal colon mucosa had negative or weak staining. Adenomas had higher SphK1 expression versus normal mucosa, and metastatic colon cancers had higher SphK1 expression than those without metastases. In an azoxymethane (AOM) murine model of colon cancer, SphK1 and S1P were significantly elevated in colon cancer tissues compared to normal mucosa. Moreover, blood levels of S1P were higher in mice with colon cancers than in those without cancers. Importantly, SphK1−/− mice subjected to AOM had significantly less aberrant crypt foci (ACF) formation and significantly reduced colon cancer development. These results suggest that the SphK1/S1P pathway contributes to colon carcinogenesis and that inhibition of this pathway is a potential target for chemoprevention. In this paper, we discuss more details of the role of the SphK1/S1P pathway in colon carcinogenesis and the effects of SphK1 inhibition in cardiovascular risk.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B80.
Abstract B82: The TASK2 potassium ion channel is differentially expressed in ER-negative breast cancer
Authors: Shen Qiang , Brown Powel
Published: May 2012

Current use of selective estrogen receptor modulators (SERMs) such as tamoxifen and raloxifene, and aromatase inhibitors has reduced breast cancer incidence in high-risk women to develop ER-positive breast cancer. However, a significant portion of ER-positive and all ER-negative breast cancers (both count for ∼60% of all breast cancer) are not prevented with these preventive drugs. Thus, new targets and more effective agents for the prevention of ER-positive and especially ER-negative breast cancer are urgently needed. Ion channels are specific cellular membrane proteins that transport inorganic ions in and out of cells to maintain membrane integrity, cell polarity and cellular homeostasis and may therefore play critical role in transforming normal epithelial cells into malignant cells. The ion channels for transporting Na+, Ca2+, and K+ ions are deregulated in many cancer types including breast cancer. Potassium ion channels are essential in non-excitable cells for regulation of cell volume, secretion of ions and hormones, and are required for maintaining cellular homeostasis. A number of potassium channels such as TASKs, GIRK1, Kca1.1, Kv1.1 and Kv1.3 are differentially expressed in normal breast tissue and breast cancer tissues. We hypothesized that TASKs may be involved in the development of ER-negative breast cancer. We first examined the public microarray databases which contain the mRNA expression profiles from multiple series of human breast cancer samples (http://www.oncomine.org). Transcription of the majority of ion channels for sodium, potassium and calcium were compared in intra-database and inter-database manners. Most of the ion channels show insignificant variations comparing ER-positive versus ER-negative breast cancers. However, TASK2 of the TASKs potassium ion channel family is overexpressed in human breast carcinomas but not in normal mammary gland tissue in three studies. Furthermore, TASK2 is significantly up-regulated in ER-negative vs ER-positive breast cancers in two studies. We then examined expression of TASK2 protein among breast cancer cell lines. TASK2 protein level was undetectable in four ER-positive breast cancer cell lines, while medium/high expression in majority of ER-negative breast cancer cells (all Basal A and Basal B subtypes). We are now investigating the phenotypic alterations in normal and malignant breast cells after overexpressing or knocking down TASK2 gene. Current results suggest that TASK2 may play a role in malignant transformation of breast cells into ER-negative breast cancer cells and maintenance of an ER-negative phenotype. Thus, TASK2 is a potential novel target for future preventive intervention of breast cancer.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B82.
Abstract B86: JS-K, a nitric oxide-donating prodrug, modulates β-catenin/TCF signaling in leukemic Jurkat cells through S-nitrosylation
Authors: Chattopadhyay Mitali , Goswami Satindra , Nath Niharika , Rodes Deborah B. , Saavedra Joseph E. , Keefer Larry K. , Kashfi Khosrow
Published: May 2012

Introduction: Leukemia is the most common form of cancer in children and acute lymphoblastic leukemia (ALL) is the primary cause of cancer-related mortality. The deregulation of theWnt signaling cascade and its components has been implicated in T-cell ALL as well as in B-cell chronic lymphocytic leukemia (CLL). The protein β-catenin has a central role in Wnt signaling pathway and may promote leukemia cell proliferation and differentiation. β-catenin is expressed in T- ALL cells, tumor lines of hematopoietic origin and primary leukemia cells but is undetectable in normal peripheral blood T cells. Among the leukemic cell lines, β-catenin is expressed in high levels in Jurkat T-cells. JS-K [O2-(2,4-dinitrophenyl)1-[(4-ethoxycarbonyl)piperazin-1yl]diazen-1-ium-1,2-diolate] is a prodrug of the diazeniumdiolate class that releases NO through a reaction catalyzed by GST utilizing glutathione. This agent has been shown to inhibit the growth of various cancer cell lines. This report highlights the effects of JSK on the growth properties of human Jurkat T-acute lymphoblastic leukemia cells, the β-catenin signaling pathway, and protein S-nitrosylation.

Methods: JS-K: synthesized by us. Cell growth: MTT; cell cycle phase distribution: flow cytometry; apoptosis: subdiploid (sub-G0/G1) peak in DNA content histograms. Transient transfection: luciferase reporter constructs TOPflash or FOPflash. Luciferase activity: kit per manufacturer's instructions. Protein S-nitrosylation: Biotin switch assay (Jaffrey et al, Nature Cell Biology, 2001, 3, 193–197); β-catenin and biotinylated protein levels: immunoblotting.

Results: JS-K inhibited the growth of Jurkat cells, IC50s of 12 ± 3 µM and 7 ± 1 µM at 24 h and 48 hr, respectively. This effect was due, in part, to a dose-dependent induction of apoptosis and alterations in the distribution of the cells in the cell cycle, arrest was in G0/G1. JS-K dose-dependently inhibited β-catenin/TCF-4 signaling by reporter assays, and reduced β-catenin levels in the nucleus and cytoplasm. JS-K treatment for 24 hr at 0.5 × IC50, 1 × IC50 and 2 × IC50 caused an increase in total S-nitrosylated proteins and also caused a reduction in S-nitrosylated β-catenin expression. These effects were reversed by carboxy-PTIO (an NO scavenger).

Conclusions: These findings establish a strong inhibitory effect of JS-K in human Jurkat T-acute lymphoblastic leukemia cells, an effect that is through inhibition of Wnt/β-catenin/TCF-4 signaling and through induction of apoptosis modulated by protein S-nitrosylation.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B86.
Abstract B88: Local delivery of breast cancer chemopreventives using mesenchymal stem cells
Authors: Greene Amy , Parke Donna , Gingery Anne , Zhdankin Olga , Skildum Andrew , Holy Jon , Perkins Edward , Rose-Hellekant Teresa A.
Published: May 2012

The overall goal of this study is to evaluate the ability of bone marrow mesenchymal stem cells (MSCs) to act as vehicles for local delivery of chemopreventives in mice that develop mammary cancer. Recently, efforts to use adult-derived stem cells to deliver therapeutic agents to tumor sites have shown great promise and we currently are extending this concept to include the delivery of gene therapy in the form of chemopreventives. Our goals in this initial project were to (1) isolate and study the behavior of transplanted MSCs in mammary glands of mice and (2) develop a gene expression system which robustly produces gene therapeutics. For gene therapy we aimed to target epidermal growth factor (EGFR/ErbB1/HER1) because activation of this growth factor pathway is a frequent component driving breast cancer proliferation and survival and recent evidence demonstrated that the EGFR pathway is more active in hyperplastic enlarged lobules compared with normal terminal ductal lobular units (AJP 2007 171, 253–262), indicating that EGFR activation is a very early event that precedes cancer development and therefore inhibiting EGFR may abrogate cancer development. To carry out this goal we developed an expression system that produces the natural inhibitory ligand of EGFR, decorin. Decorin is a small leucine rich proteoglycan with known effects in extracellular matrix assembly as well as growth inhibition via reduction in levels and activity of EGFR along with other signaling molecules. Thus far we have demonstrated the ability to isolate, culture and maintain murine MSCs from the FVB/N strain in an undifferentiated state. In addition, these MSCS do not form tumors upon transplantation into mammary glands of syngeneic mice. Furthermore, we have produced secreted decorin in Chinese hamster ovarian cells and MSCs. Finally, we demonstrate the ability of conditioned media containing decorin to inhibit mammary tumor cell proliferation in vitro. Our long-term goal is to test the efficacy of decorin-engineered MSCs as a breast cancer prevention modality in mouse models.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B88.
Abstract B9: Geographic disparity in HPV vaccination among girls in six U.S. states
Authors: Pruitt Sandi L. , Schootman Mario
Published: May 2012

Introduction: The human papillomavirus (HPV) vaccine was approved by the Food and Drug Administration in 2006. Since that time, limited research has examined HPV vaccine uptake among adolescent females and no studies have examined the role of disparities in HPV vaccination. The purpose of this study is to examine geographic disparity in the prevalence of HPV vaccination and to examine individual-, county-, and state-level correlates of vaccination.

Methods: Three-level random intercept logistic regression models were fitted to data from 1,709 girls aged 13–17 living in 6 U.S. states using 2008 Behavioral Risk Factor Surveillance System and 2000 U.S. Census data.

Results: Overall, 34.4% of girls were vaccinated. Significant geographical disparity across states (Var: 0.134 SE: 0.065) and counties (Var: 0.146 SE: 0.063) was present, which was partially explained by state- and county-level poverty rates. Independent of individual-level factors, poverty had differing effects at the state- and county-level: girls in higher poverty states were less likely while girls in higher poverty counties were more likely to be vaccinated. Household income demonstrated a similar pattern to that of county-level poverty: compared to girls in the highest income families, girls in the lowest income families were more likely to be vaccinated.

Conclusions: The results of this study suggest geographic disparity in HPV vaccination and area-level effects of poverty that have not previously been studied. The higher odds of vaccination among girls living in higher poverty counties and low income families may indicate the success of publicly-funded vaccination efforts targeting the underserved or a bias against vaccination among higher income groups. Overall vaccination rates continue to be sub-optimal however, and future research is needed to examine the impact of state- and local-area policies and to increase vaccination among eligible girls.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B9.
Abstract B90: Doses of selective estrogen receptor modulations (SERMs) required for prevention and therapy of chemically induced mammary cancers
Authors: Heckman-Stoddard Brandy M. , Grubbs Clinton , Lubet Ronald
Published: May 2012

Selective Estrogen Receptor Modulators (SERMs) interfere with the activity of estrogen. SERMs have been shown to be effective for both treatment and prevention of breast cancer. Here we examine the ability of Tamoxifen and Arzoxifene, a more easily absorbed form of Raloxifene, to prevent mammary tumors at a significantly lower dosage than those used for treatment. For prevention studies, treatment of female Sprague-Dawley rats (50 days of age) with a single dose of MNU resulted in the development of multiple ER-positive mammary tumors beginning 7 weeks after carcinogen treatment. When examined in a chemoprevention setting, rats were administered the preventive agent beginning five days after carcinogen administration. When the agents were tested at does varying between 0.15–3.3 ppm in the diet, both agents caused a dose dependent increase in preventive activity. The highest doses of tamoxifen (3.3 ppm) and Arzoxifene (3.0 ppm) both decreased tumor multiplicity greater than 90%. Both of these doses are less than one-fifth the human equivalent dose (HED) based on standard FDA scaling factors. Both doses also resulted in substantial decreases in mammary gland development. These dosages were then used in a therapy setting to compare the efficacy. For these studies, MNU treated rats were allowed to develop their first palpable mammary tumor (70–150 mm2) before initiating treatment. Tumor growth or regression was followed by caliper measurements. Neither of the higher preventive doses of these SERMs exhibited substantial therapeutic activity, although substantially higher doses of tamoxifen (33 or 100 ppm) were relatively effective. These results are in contrast to our prior findings with other classes of agents (RXR agonists, EGFR inhibitors, and aromatase inhibitors) in which highly effective preventive doses were effective as the therapeutic doses in this model. These results demonstrate the unique dose differential regarding prevention and therapy with SERMs. It raises the question of whether this class of agents might be used at significantly lower doses in a pure prevention setting.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B90.
Abstract B91: Induction of RXR transcriptional activity and consequent upregulation of p21 by 3-amino-6-(3-aminopropyl)-5,6-dihydro-5, 11-dioxo-11H-indeno[1,2-c]isoquinoline dihydrochloride in MCF-7 breast cancer cells
Authors: Park Eun-Jung , Kondratyuk Tamara , Morrell Andrew , Kiselev Evgeny , Cushman Mark , Pezzuto John
Published: May 2012

Retinoid X receptor (RXR) is known to play various roles in embryogenesis, metabolic processes, differentiation, and apoptosis. Recently, RXR has been studied as a target for cancer chemoprevention and treatment. To discover potential cancer chemopreventive agents acting through RXRs, we developed a cell line-based RXR response element (RXRE)-luciferase reporter gene assay system. Following extensive screening, 3-amino-6-(3aminopropyl)-5,6-dihydro-5,11-dioxo-11H-indeno[1,2-c]isoquinoline dihydrochloride (AM6-36) was found to induce RXRE-luciferase activities in a dose-dependent manner. Subsequently, the substance was found to inhibit the proliferation of MCF-7 breast cancer cells in a concentration-dependent manner. Prompted by these results, we examined the underlying mechanism of AM6-36 anti-proliferative activity using MCF-cells as a model. In brief, at lower concentrations, G2/M arrest was observed, and S phase arrest was enhanced at higher concentrations. Based on DNA microarray analysis, AM6-36 was found to up-regulate the expression of CDKN1A, a target gene of RXR, by ∼40-fold. In accordance with this response, the protein level of CDKN1A (p21WAF1/CIP1) was increased in the presence of AM6-36. Induction of p21 by AM6-36 was abrogated following transient transfection of RXR siRNA, demonstrating the effect of AM6-36 on the expression of p21 is closely related to modulation of RXR transcriptional activity. These data suggest AM6-36 is a promising lead compound for the treatment or prevention of breast cancer. A synthetic procedure has been devised for large-scale production, moderate absorption and slow metabolism has been demonstrated with rats (p.o. administration), and more advanced anti-tumor evaluation is underway. (Supported by program project P01 CA48112 awarded by the National Cancer Institute.)

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B91.
Abstract B92: Combating prostate cancer by targeting androgen receptor with phytochemical resveratrol
Authors: Zhang Dianzheng
Published: May 2012

The chemopreventive effects of resveratrol (RSV) on prostate cancer have been well established; the androgen receptor (AR) plays pivotal roles in prostatic tumorigenesis. However, the exact underlying molecular mechanisms about the effects of RSV on AR have not been fully elucidated. A model system is needed to determine whether and how RSV represses AR transcriptional activity. The AR cDNA was first cloned into the retroviral vector pOZ-N and then integrated into the genome of AR-negative HeLa cells to generate the AR(+) cells. The constitutively expressed AR was characterized by monitoring hormone-stimulated nuclear translocation, DNA binding, and transcriptional activation, with the AR(−) cells serving as controls. AR(+) cells were treated with RSV, and both AR protein levels and AR transcriptional activity were measured simultaneously. Chromatin immunoprecipitation (ChIP) assays were used to detect the effects of RSV on the recruitment of AR to its cognate element (ARE). AR in the AR (+) stable cell line functions in a manner similar to that of endogenously expressed AR. Using this model system we clearly demonstrated that RSV represses AR transcriptional activity independently of any effects on AR protein levels. However, neither the hormone-mediated nucleus translocation nor the AR/ARE interaction was affected by RSV treatment. We demonstrated unambiguously that RSV regulates AR target gene expression, at least in part, by repressing AR transcriptional activity. Repressive effects of RSV on AR activity result from mechanisms other than the affects of AR nuclear translocation or DNA binding.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B92.
Abstract B93: Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers may decrease cancer-related mortality in patients with small-cell lung cancer
Authors: Arnaout Karim , Farhan Shatha , Rana Jatin , Jankowski Michelle , Wang Ding
Published: May 2012

Introduction: Small-cell lung cancer (SCLC) is the most aggressive type of lung cancer. The overall survival at five years for patients with SCLC is estimated to be five to ten percent. Angiotensin-Converting Enzyme (ACE) inhibitors and Angiotensin Receptor Blockers (ARBs) have been reported to decrease the risk of lung cancer. The aim of this retrospective study was to investigate the association between ACE inhibitors and ARBs and cancerrelated mortality in patients with SCLC.

Methods: In this study, we retrospectively reviewed the charts of 360 patients diagnosed with SCLC in our institution between 1995 and 2004. 199 patients with advanced SCLC, deceased at the time of this report, and for whom the cause of death was known, were identified. Within this group, cancer-related mortality in patients who were on ACE inhibitors and/or ARBs was compared to that of patients not on these medications.

Results: Out of 199 patients, 58 (29%) were on ACE inhibitors and/or ARBs, 141 (71%) were not. In ACE inhibitor and/or ARB users, cancer was the cause of death in 34 patients. In patients not on ACE inhibitors and/or ARBs, 103 died from cancer. Patients on ACE inhibitors and/or ARBs had a 14% decrease in cancer-related mortality compared to patients who were not on these medications (59% versus 73% respectively, P= 0.046).

Conclusion: Our data support the fact that ACE inhibitors and ARBs may be associated with a decrease in cancer-related mortality in patients with SCLC. This could be related to their inhibitory effects on angiogenesis and tumor growth, by blocking angiotensin II and increasing the levels of angiotensin (1–7). However, prospective studies are needed to establish the effect of ACE inhibitors and ARBs on cancer-related mortality in patients with SCLC.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B93.
Abstract B96: Phylogenetic relatedness and novel mutations in the whole genomes of genotype A (subgenotype A1) of HBV isolates from a north Indian population
Authors: Singh Jasbir , Pahal Vikas , Kumar Rajesh
Published: May 2012

Hepatitis B virus (HBV) has been classified into eight genotypes (A to H). The predominant genotypes in India are genotype D followed by genotype A and C. Our laboratory has first time reported genotypes E and F in India. In the present study, whole genome (approximately 3.2 kb long) was amplified from five chronic HBV patients, who are HBeAg negative and having nearly normal ALT/AST levels. The samples were sequenced to complete length and sequences were compared to wild type sequences from database. Phylogenetic analysis shows high degree of closeness of our strains with Philippines and eastern Indian strains. Our study confirmed 33–35 point mutations out of already reported 38 subgenotype A1 specific point mutations and which are distributed throughout the genome including enhancer I–X promoter, enhancer II-Core promoter, encapsidation signal, S1 and S2 promoter regions etc. In addition to this, novel Kozak sequence mutations like CCTT at positions 1809/10/11/1812 in place of regular TCAT sequence were also observed. This region comprises the Enhancer II-Core promoter region and mutations of this region results in decreased production of HBeAg. 1041G was present in place of 1041T in Enhancer I–X promoter region. It has been observed that Genotype A has G1896A mutation when preceded by a C1858T mutation, thus conserving the structural stability of the encapsidation signal. One sample shows the presence of 1858T with 1896G mutation, which results in weakness of structural stability of encapsidation signal. In addition, our samples show presence of 1862T which is a missense mutation and responsible for val to leu/phe amino acid substitution. This mutation is responsible for low production of HBeAg protein and found mainly in HBeAg negative patient. Samples also showed the deletion at 19 novel sites and addition at 5 novel sites when compared with the whole genome from database. The significance of these deletion and addition mutations and their effects on the disease progression to hepatocellularcarcinoma is active area of research in our laboratory.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B96.
Abstract B97: Alcoholic beverages and prostate cancer in a prospective U.S. cohort study
Authors: Watters Joanne , Park Yikyung , Hollenbeck Albert , Schatzkin Arthur , Albanes Demetrius
Published: May 2012

Higher alcohol consumption has been shown to be a risk factor for many cancers, yet despite a number of investigations, its relation to prostate cancer has not been established. We investigated the association between alcohol consumption and risk of prostate cancer in a large prospective study of dietary and environmental cancer risk factors among 294,707 men aged 50–71 years old upon enrollment in 1995–1996. Cox proportional hazards regression models with hazard ratios (HR) and 95% confidence intervals (95% CI) were adjusted for several characteristics including age, race, body mass index, physical activity, family history of prostate cancer, and PSA and DRE testing. There were 15,327 nonadvanced and 1,900 advanced incident prostate cancers identified through 2003 and 514 men died of prostate cancer through 2005. Risk of nonadvanced prostate cancer was 25% higher in men consuming 6 or more drinks per day (HR= 1.25, 95% CI: 1.13 – 1.37), 19% higher in men consuming between 3 and 6 drinks per day (HR= 1.19, 95% CI: 1.11 – 1.29), and 6% higher in men consuming up to 3 drinks per day compared to nondrinkers (HR= 1.06, 95% CI: 1.00 – 1.12). The lowest risk of nonadvanced prostate cancer was seen among nondrinkers. We observed no association between alcohol intake and advanced cancers and a possible association against fatal prostate cancer among a small number of heavy drinkers with 6+ drinks daily (HR= 0.45, 95% CI: 0.25 – 0.81). There were similar associations observed for all types of alcoholic beverages (i.e., wine, beer, liquor). In this large prospective study, we found that alcohol consumption modestly increased the risk of nonadvanced prostate cancers.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B97.
Abstract B98: Dietary fiber is associated with circulating concentrations of inflammatory markers among breast cancer survivors
Authors: Villaseñor Adriana , Ambs Anita , Ballard-Barbash Rachel , Baumgartner Kathy B. , Coronado Gloria , McTiernan Anne , Ulrich Cornelia M. , Neuhouser Marian L.
Published: May 2012

Introduction: An association between high intake of dietary fiber and low circulating concentrations of inflammatory markers has been suggested by previous research. However, epidemiological data from cohort studies of breast cancer survivors are sparse.

Methods: We examined associations between dietary fiber and serum concentrations of CRP and SAA, among 698 female breast cancer survivors from the Health, Eating, Activity, and Lifestyle (HEAL) Study. Data are from an interview conducted 24 months after study enrollment. Multivariate-adjusted linear regression estimated the association of total, soluble and insoluble fiber with serum concentrations of CRP and SAA. Logistic regression estimated the odds of elevated CRP (defined as >3.0 mg/L) across tertiles of fiber intake.

Results: Mean total dietary fiber intake was 13.96 ± 6.38 gm/day. Mean CRP and SAA were 3.32 ± 3.66 mg/L and 7.73 ± 10.23 mg/L, respectively. After controlling for potential confounders, including age, body mass index (BMI), smoking, physical activity, total caloric intake, alcohol consumption, fat intake, postmenopausal status, inflammatory-related diseases, medication use, disease stage and adjuvant treatment, we observed an inverse association between intake of total dietary fiber intake and CRP concentrations (β, −0.029; 95% CI, −0.049, −0.008). SAA was not associated with fiber intake (β, −0.002; 95% CI, −0.016, 0.012). Among the various fiber fractions of dietary fiber, only insoluble fiber was inversely associated with circulating concentrations of CRP (β, −0.039; 95% CI, −0.064, −0.013). The likelihood of elevated CRP concentrations was lower (OR, 0.57; 95% CI, 0.30, 1.07) among participants who consumed >16 g/day total dietary fiber compared with consumption of 15.5 g/day of insoluble dietary fiber compared to those who reported <5.4 g/day with moderate significance (p = 0.053).

Conclusion: Our results suggest that diets high in fiber may be of benefit to breast cancer survivors due to fiber's correlation with lower circulating concentrations of CRP, recently shown to affect breast cancer survival.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B98.
Abstract CN04-03: Esophageal cancer and the tumor microenvironment
Authors: Rustgi Anil K. , Stairs Douglas B. , Grugan Katharine D. , Wong Gabrielle S. , Vega Maria E. , Kalabis Jiri , Nakagawa Hiroshi , Gimotty Phyllis A. , Klein-Szanto Andres J. , Diehl J.Alan , Herlyn Meenhard
Published: May 2012

Squamous cell cancers are the most common type of epithelially derived human cancers and arise from a number of diverse sites. They share a number of common genetic alterations and environmental exposures. Employing oral and esophageal cancers as prototypes, we have developed three-dimensional (3D) or organoptypic models that represent a form of human tissue engineering (Genes and Development 2007; Journal of Clinical Investigation 2008). These approaches underscore the combinatorial roles of EGFR signaling and p53 mutation in fostering tumor cell migration and invasion in the microenvironment. Microarray analyses reveal specific effectors in the adhesion family of genes that might be exploited as biomarkers for detection and targets for new therapeutics. We have also generated genetically engineered mouse models that reveal the effects of cyclin D1 overexpression in concert with p53 loss, as well as the role of p120-catenin loss in the initiation and progression of cancer.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):CN04-03.
Abstract CN05-02: Energy balance and cancer at the bench: What's new?
Authors: Thompson Henry J.
Published: May 2012

Evidence is strong that a reduction in risk for certain types of cancer is associated with moderate to vigorous physical activity (PA); however, there is limited understanding of the role of type, intensity, duration, and frequency of PA and their mechanisms in accounting for this health benefit. The objective of this presentation is to provide insights from preclinical investigations of PA and breast cancer that inform the general understanding of candidate mechanisms that may account for both the energy dependent and independent effects of PA. Hypotheses about cellular mechanisms will be linked to hypotheses to about systemic effects of PA. Issues considered will include: 1) what contracting muscle releases into circulation or removes from circulation that would directly modulate the carcinogenic process in epithelial cells; 2) whether the effects of muscle contraction on epithelial cell carcinogenesis are exerted in an endocrine, paracrine, autocrine, or intracrine manner; and 3) if the effects of muscle contraction on malignant cells differ from effects on normal or premalignant cells that do not manifest the hallmarks of malignancy.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):CN05-02.
Abstract CN07-03: Polymorphisms in miRNA binding sites as risk factors for cancer development
Authors: Weidhaas Joanne B.
Published: May 2012

Purpose: Ovarian cancer is the single most deadly form of cancer specific to women, largely due to a lack of known risk factors or genetic markers. The KRAS oncogene and altered levels of the microRNA let-7 are associated with increased risk of developing solid tumors, such as ovarian cancer. We investigated a single nucleotide variant (rs61764370) that disrupts a let-7 microRNA binding site in the KRAS oncogene as a biomarker of ovarian cancer risk.

Methods: Specimens were obtained from non-selected ovarian cancer patients in three independent cohorts (n = 445) and two independent ovarian case-control studies. Specimens from ovarian cancer patients with hereditary breast and ovarian cancer (HBOC) syndrome (n = 52) and their family members were also collected.

Results: rs61764370 is in greater than 30% of non-selected ovarian cancer cases and is a marker for a significant increased risk of developing ovarian cancer by case control analysis (n = 201, OR = 2.46, CI = 1.14–5.29, p = .020). This was validated in a second independent ovarian case-control (n = 648). Furthermore, rs61764370 was identified in 58% of HBOC patients without BRCA1 or BRCA2 mutations (n = 24, p < 0.001), therefore previously considered uninformative, as well as in their family members with cancer.

Conclusions: These findings support the hypothesis that rs61764370 is a genetic marker of increased risk of developing ovarian cancer, and suggests that rs61764370 may be a new biomarker of risk for HBOC families without other known genetic abnormalities.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):CN07-03.
Abstract CN07-04: RNAi in the treatment and epigenetics of cancer
Authors: Rossi John J. , Sun Guiha , Kim Daniel
Published: May 2012

RNA interference is a broad term used to describe several different mechanisms for regulation of gene expression mediated by small RNAs. Small interfering RNAs (siRNAs) trigger sequence specific cleavage of mRNAs via fully complementary base pairing, resulting in cleavage and subsequent total degradation of the targeted transcript. Micro RNAs (miRNAs) are the guides for triggering translational inhibition of gene expression via partially complementary pairing to the 3′ UTRs of target transcripts. Small RNAs can also modulate gene expression via directing chromatin remodeling, resulting in heterochromatin formation and silencing of transcription. Each of these mechanisms has important implications for the prevention and diagnosis of cancer. SiRNAs are not commonly found in mammalian cells, but may be present during gametogenesis to control retroposon movement. The functional consequences of aberrations in the production and functioning of siRNAs could lead to genomic rearrangements and other chromosome abnormalities. MiRNAs have been shown to be important micro-managers of gene expression, and a single miRNA can repress translation of upwards of two hundred different proteins. MiRNA profiling has shown that aberrant expression of these micro-managers can be diagnostic and prognostic for several different cancers. Given the importance of miRNAs in controlling cell fates and ultimately progression to cancer, it is important to understand what types of aberrations can affect their function. Micro RNAs are produced via a two step processing reaction involving two different RNAse III family members (Drosha and Dicer) and their cofactors. Perturbations of either of these processing steps can alter the amount and even the final processed sequence of miRNAs. The first part of this presentation will focus on naturally occurring point mutations identified in X-linked miRNA genes and the consequences of these mutations on miRNA function. Point mutations in miRNA precursors as well as mature sequences can lead to altered miRNA function and could have a profound effect on regulation of the translation of both targeted and non-targeted mRNAs.

Small RNAs that can modulate chromatin structure also present a possible tool for cancer prevention. Two examples of small RNAs modulating chromatin structure will be presented. The first example is the use of promoter targeting siRNAs to silence an important tumor suppressor, RASFF1A. The second example illustrates how an endogenous microRNA targeting a promoter region can modulate expression of an essential RNA Polymerase 3 subunit.

The last part of this presentation will focus on some strategies for delivering siRNAs or miRNAs in a targeted fashion to modulate expression of genes. These strategies could be useful in cancer prevention and as cancer treatments.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):CN07-04.
Abstract ED06-04: Methodology for benchmarking recruitment of minority and lower SES populations to clinical trials
Authors: Morgenlander Keith H.
Published: May 2012

Background: The National Cancer Institute (NCI) has historically evaluated the participation of underserved minorities within University of Pittsburgh Cancer Institute (UPCI) clinical trials in relation to the African Americans (AA) general population within the UPCI primary service area of Allegheny County (12%). This standard appeared to be unrealistically high, due to a younger age distribution of AAs within the county.

Methods: The proportion of AAs within four separate county populations were compared, using data from 2000–2004: (a) general population, (b) invasive cancer cases (c) invasive cancer cases diagnosed or treated at UPCI-affiliated facilities and (d) patients enrolled on UPCI's clinical therapeutic trials.

Results: The proportion of AAs within the general population was approximately 12%. However, only 9.8% of patients diagnosed with invasive cancers were AA. Approximately 9.5% of all cancer cases diagnosed or treated at UPCI facilities was AA, comparable to the county-wide percent of AA cancer patients. Recruitment of AAs to oncology clinical trials was 7.6%, revealing a significant disparity.

Discussion: The NCI benchmark did not reflect the actual “pool” of potential AA patients. As an alternative, we compared the percentage of AAs contributing to cancer incidence with the percentage AA cancer patients treated at the research-affiliated institutions and with the proportion of AAs enrolled on clinical therapeutic trials.

Conclusions: This methodology was successfully utilized by UPCI and should be useful as a mechanism for benchmarking recruitment of underserved and minority cancer patients at other cancer centers.

Primary Reference: Morgenlander KH, Winters SB, Lin CJ, Robertson LB, Heron DE, Herberman RB. A novel method for benchmarking clinical trial recruitment of African American cancer patients. J Clin Oncol. 2008 Nov 1;26(31):5074–7.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):ED06-04.
Abstract ED07-02: Effects of chronic stress on cancer metastasis
Authors: Sood Anil K. , Lutgendorf Susan K. , Cole Steve W.
Published: May 2012

The notion that psychosocial factors can affect malignant progression has long been suspected. Clinical and epidemiological studies have recognized that specific psychosocial factors, such as stress, chronic depression, and lack of social support are risk factors for more rapid progression of cancer. However, the underlying mechanisms for this association are poorly understood. Cancer metastasis is a sequential and complex process that results in widespread dissemination of cancer cells. We have performed a series of in vitro and in vivo experiments using mechanistic manipulations to identify specific neuroendocrine signaling pathways that mediate direct effects of chronic stress on tumor cell biology. These studies focused on the effects of catecholamine neurotransmitters on angiogenic pathways that support the growth and progression of human ovarian carcinoma as well as other steps in the metastatic cascade. Findings indicate that chronic stress affects multiple steps during metastasis, resulting in greater tumor burden and more invasive growth in orthotopic mouse models. Moreover, catecholamines modulate the expression of genes encoding angiogenic factors (e.g., VEGF) via β-adrenergic receptors expressed on the human tumor cell surface. These effects are mediated primarily through activation of the tumor cell cyclic AMP (cAMP)-protein kinase A (PKA) signaling pathway by the 2-adrenergic receptor. These data implicate β-adrenergic activation of the cAMP-PKA signaling pathway as a major mechanism by which behavioral stress can enhance tumor angiogenesis and growth. At a clinical level, circulating levels of angiogenic factors such as VEGF and IL-6 are correlated with greater distress and inversely related to social support. Our recent studies demonstrate that relationships between psychosocial factors and angiogenic factors extend to the tumor microenvironment as well. Dissecting these pathways by which chronic stress provides support for angiogenesis and other steps in metastasis could have therapeutic implications for cancer management.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):ED07-02.
Abstract ED07-04: Identifying environment-gene interactions that link social stress to altered cancer biology
Authors: Conzen Suzanne D. , McClintock Martha K.
Published: May 2012

Identifying the potential mechanisms linking psychosocial factors (e.g. chronic “stress”) to human disease susceptibility has been the subject of intense interest by both social and biological scientists for many years. Together, the endocrine and the autonomic nervous systems modulate an individual's physiological response to social stress; both systems can mediate signaling pathways and gene expression changes at the subcellular level that have the potential to alter tumor biology. However, it is only recently that the detailed molecular components connecting biobehavioral factors and cancer biology have begun to be uncovered. For example, in preclinical models of both breast and ovarian cancer, there is growing evidence linking environmental stressors and ensuing changes in neuroendocrine dynamics to the promotion of tumor growth. These mechanisms include decreasing tumor cell apoptosis and increasing cell proliferation, tumor invasion, and angiogenesis. Assessing the mechanisms of gene by social environment interaction requires an appreciation of the subtleties of measuring the social environment, the individual's behavioral and neuroendocrine response, as well as the tumor and its microenvironment.

While cancer biologists are accustomed to examining the effects of a single physical variable on a well-defined and measurable outcome, examining the physiological outcomes of an adverse social environment on tumor biology requires expanding expertise beyond the usual expertise of a tumor biologist. These studies require developing models that require scientists from diverse backgrounds of expertise to look beyond single agents and to consider the complexity of the individual's interaction with the social environment, and the resultant molecular sequelae as it influences tumor development.

Our laboratories' recent collaborative development of a model of social isolation as it pertains to a transgenic model of human breast cancer (SV40Tag) and a Sprague-Dawley female rat model of spontaneous mammary gland cancer will be presented. In both models, we found that chronic social isolation results in altered exploratory behavior to an open field as well as a heightened corticosterone response to a superimposed acute restraint stressor. In the SV40 Tag model, we were able to examine gene expression differences in the mammary glands of isolated versus grouped female mice prior to invasive tumor development and uncovered a significant increase in the expression of genes encoding lipid synthesis and glycolytic pathway enzymes, suggesting an association of the environment with cancer-associated metabolic changes. The implications and limitations of these two breast cancer models - one transgenic and one spontaneous - will be discussed within the context of understanding mechanisms that confer biological risk in association with an unfavorable social environment.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):ED07-04.