bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Patupilone on the Pharmacokinetics and Pharmacodynamics of Warfarin in Patients with Advanced Malignancies: A Phase I Clinical Trial
Authors: Tsimberidou Apostolia-Maria , Takimoto Chris H.M. , Moulder Stacy , Uehara Cynthia , Mita Monica , Mita Alain , Urban Patrick , Tan Eugene , Wang Yanfeng , Vining David , Kurzrock Razelle
Published: January 2011

Patupilone is a novel microtubule-targeting cytotoxic agent, which exerts its antitumor effect through microtubule stabilization. Pharmacokinetics, pharmacodynamics, and safety of warfarin when administered concomitantly with patupilone were investigated, and antitumor activity was assessed. This was a phase I, two-center, drug–drug interaction study. In the core phase of the study, treatment consisted of warfarin 20 mg orally (days 1 and 29) and patupilone 10 mg/m2 i.v. (days 8 and 29). Patients benefiting from patupilone treatment continued treatment every 3 weeks (extension phase) until progression of disease, death, or unacceptable toxicity. Seventeen patients were treated (core phase, 17; extension, 9). The geometric mean ratios (comedication/monotherapy) for Cmax and area under the curve0–168 of warfarin were near unity and their 90% confidence intervals were within the equivalence limits of 0.80 and 1.25. The half-life, plasma clearance, and International Normalized Ratio (INR) of warfarin were not affected by patupilone coadministration. The most common adverse events were diarrhea, nausea, vomiting, abdominal pain, anorexia, dehydration, asthenia, and peripheral neuropathy. Five (29.4%) patients experienced grade 3 study drug-related adverse events (diarrhea, 17.6%; increased INR, 11.8%; dehydration, 5.9%; and neutropenia, 5.9%). One patient with triple-negative breast cancer (estrogen receptor, progesterone receptor, and HER2/neu negative) had a partial response (35% decrease in tumor measurements by Response Evaluation Criteria in Solid Tumors), and 11 had stable disease for 6 weeks or more (≥12 weeks, 6 patients). The pharmacokinetics and pharmacodynamics of warfarin were not affected by patupilone coadministration, suggesting that patupilone has no clinically relevant effect on CYP2C9 metabolism. Patupilone showed antitumor activity in triple-negative breast cancer. Mol Cancer Ther; 10(1); 207–17. ©2011 AACR.
Abstract A101: Dose-related suppression of rat oral carcinogenesis by the EGF receptor-tyrosine kinase inhibitor, gefitinib
Authors: Horn Thomas L. , Johnson William D. , Lubet Ronald A. , Steele Vernon E. , McCormick David L.
Published: January 2011

Activation of the epidermal growth factor receptor (EGFR) stimulates signal transduction pathways that regulate cell proliferation and may be causally involved in carcinogenesis. Recent data suggest that EGFR expression is a predictive biomarker for the risk of oral cancer in humans, and that alterations in EGFR expression or action may be directly involved in oral carcinogenesis. Gefitinib (N-(3-chloro-4-fluoro-phenyl)-7-methoxy-6-(3-morpholin-4-ylpropoxy)-quinazolin-4-amine; ZD1839; Iressa) is a specific inhibitor of EGFR tyrosine kinase (EGFR-TK). The present study was performed to evaluate the activity of gefitinib as an inhibitor of oral cancer induction in rats. Squamous cell carcinomas of the tongue were induced in male F344 rats by drinking water administration of 4-nitroquinoline-1-oxide (NQO; 20 ppm for 10 weeks). After NQO administration was completed, rats were randomized into groups of 25 and received [a] unsupplemented basal diet only (dietary control); [b] basal diet + gefinitib (50 mg/kg diet); or [c] basal diet + gefinitib (100 mg/kg diet). All diets were fed continuously from week 10 until the end of the study at week 26. Dietary administration of gefinitib induced a dose-related inhibition of oral cancer induction (cancer incidences of 57% and 36% in low and high dose groups, respectively, versus 80% incidence in the dietary control group; p < 0.01), and prevented the body weight loss that is commonly seen in this model in animals with advanced oral cancer. While reducing the incidence of invasive oral cancers, gefinitib increased the incidence of squamous epithelial hyperplasia (35% and 40% in low and high dose groups, respectively, versus 16% in dietary controls); the increased incidence of oral epithelial hyperplasia suggests that gefinitib prevented the progression of hyperplastic lesions into invasive oral cancers. Gefinitib induced no evidence of systemic toxicity in any treated animal. PCR analysis demonstrated comparable levels of EGFR transcripts in oral cancers and site-matched phenotypically normal oral tissues harvested from age-matched animals treated with NQO. Thus, the utility of EGFR-TK as a target for oral cancer chemoprevention in this model is not clearly associated with differential expression of EGFR in neoplastic oral tissues. These data demonstrate that EGFR inhibitors may be useful for the prevention of oral cancer, and that overexpression of EGFR in these cancers is not essential for chemopreventive efficacy. (Supported by N01-CN-85163 and N01-CN-25113 from the NCI.)

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A101.
Abstract A105: Androgen regulation of 5α-reductase isoenzymes in prostate cancer: Implications for prostate cancer prevention
Authors: Li Jin , Ding Zhiyong , Wang Zhengxin , Logothetis Christopher J. , Mills Gordon B. , Kim Jeri
Published: January 2011

Finasteride, a specific inhibitor of SRD5A2, one of three isoenzymes of 5α-reductase, reduced prostate cancer incidence by 25% in the Prostate Cancer Prevention Trial, but the molecular mechanisms of its effect remain undelineated. Androgen receptor (AR) signaling is important during prostate cancer pathogenesis and progression, and 5α-reductase converts testosterone to dihydrotestosterone (DHT). We investigated how androgen regulates expression of isoenzymes of 5α-reductase encoded by different genes—SRD5A1, SRD5A2, and SRD5A3—and in turn how finasteride may affect this regulation. By using different prostate cell lines, we found that androgen regulates the mRNA level of 5α-reductase isoenzymes in a cell type-specific manner. This regulation, we demonstrated, requires AR and occurs at the transcriptional level. Moreover, we found that finasteride affects androgen regulation of 5α-reductase expression in a cell type- and AR status-dependent manner. Finasteride counteracts testosterone-driven but not dihydrotestosterone-driven regulation of 5α-reductase expression in LAPC-4 cells, which express wild type AR. However, finasteride does not affect testosterone or dihydrotestosterone regulation of 5α-reductase expression in LNCaP cells, which express a mutant AR (T877A). Our findings suggest that dihydrotestosterone is the major regulator of 5α-reductase expression and that finasteride may produce additional antitumor effects through other mechanisms besides inhibiting 5α-reductase activity. The differential expression levels of 5α-reductase isoenzymes may be one of the factors conferring response or resistance to finasteride treatment and thus may prove significant in prostate cancer prevention.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A105.
Abstract A14: DNA alterations to the Cullin-3/Ring box protein-1 E3 ubiquitin ligase complex represent a novel mechanism of NF-κB activation in lung cancer
Authors: Pikor Larissa , Thu Kelsie L. , Lockwood William W. , Chari Raj , Wilson Ian M. , MacAulay Calum E. , English John C. , Tsao Ming- Sound , Gazdar Adi F. , Lam Stephen , Lam Wan L.
Published: January 2011

Background: Nuclear factor kappa B (NF-κB) signaling is essential for lung cancer development, and therefore, may serve as a target for intervention. However, the genetic mechanisms responsible for its activation are not fully understood. Kelch-like ECH-associated protein 1 (KEAP1) binds protein substrates to the Cullin-3 (CUL3)/Ring box protein-1 (RBX1) E3 ubiquitin ligase complex where ubiquitination signals substrates for proteosomal degradation. Recently, inhibitor of nuclear factor kappa-B kinase subunit beta (IKKβ), an activator of NF-κB, was shown to be a substrate of KEAP1, implicating KEAP1's involvement in regulating NF-κB signaling. Loss of function of KEAP1 leads to IKKβ accumulation and NF-κB activation. We hypothesized that DNA deletions of the other E3 complex components (CUL3 and RBX1) are frequent alterations that disrupt complex function and contribute to NF-κB activation in lung cancer.

Methods: We screened DNA copy number profiles of 261 non-small cell lung cancer (NSCLC) tumors for DNA alterations at the KEAP1, CUL3, RBX1, and IKK loci. Profiles were generated by array comparative genomic hybridization on the SMRT array (sub-megabase resolution tiling) platform. We also analyzed mRNA expression of these genes and 9 well annotated NF-κB target genes, using gene expression profiles generated with Agilent gene expression microarrays for a subset (n=48) of the tumors.

Results: Our investigation of genetic disruption to the E3 ubiquitin ligase complex components revealed 54% of tumors harbored DNA copy number loss of at least one complex component (KEAP1, CUL3, or RBX1) or gain of IKKβ. Moreover, at the expression level, 81% of tumors analyzed had aberrant expression of one of these genes (underexpression of complex components or overexpression of IKKβ). Interestingly, the copy number alterations identified appeared to segregate with adenocarcinoma (AC) or squamous cell carcinoma (SCC) histology; KEAP1 loss was more prevalent in AC while CUL3 loss and IKKβ gain were more frequent in SCC. When NF-κB target gene expression was analyzed, we observed higher expression of 5/9 genes in tumors with underexpression of an E3 ubiquitin ligase complex component relative to matched non-malignant tissue from the same individual.

Conclusions: The presence and strikingly high frequency of genetic disruption and aberrant expression of the E3 ubiquitin ligase complex components (KEAP1, CUL3, and RBX1) revealed in this study provides evidence of its importance in lung cancer. These data suggest that DNA level alterations to this complex may represent a novel mechanism of NF-κB activation in lung cancer.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A14.
Abstract A18: Silver nanoparticles induce apoptosis by regulation of cyclic AMP response element-binding protein in lung cancer cells
Authors: Park Hee Sun , Jang Sunhyae , Cha Hye Rim , Park Ji Won , Shin Ji Young , Kim Sun Young , Koo Ja Seok , Kim Ju Ock
Published: January 2011

Recently, much effort has been devoted to the development of biomedical applications for nanoparticles (NPs). Silver NPs have been shown various therapeutic effects such as antimicrobial, antioxidant, and anti-inflammatory effects. Recently silver NPs have been shown to induce the apoptotic pathway in vitro. But exact mechanism is not yet established. We conducted this study to determine the mechanisms of silver NPs on cellular apoptosis in non-small cell lung cancer (NSCLC) cell lines using cyclic AMP response element-binding protein (CREB) activity which has been implicated to contribute an important pathobiologic role in lung carcinogenesis and is considered a potential therapeutic target for NSCLC. We hypothesized that constitutively increased CREB and its related signaling pathways can be blocked by silver NPs. To determine cytotoxic effect of silver NPs, several NSCLC cell lines were treated with various concentrations for different times. Among these lung cancer cell lines, H520, human lung squamous carcinoma cell lines, was the most sensitive. FACS analysis also showed that silver NPs induced cell death of H520 cells. Treating H520 cells with silver NPs (100, 200, or 500 M) inhibited CREB activation by blocking the activity of extracellular signal kinase/ribosomal s6 kinase and also by blocking the activity of phosphatidylinositol 3-kinase/Akt. We subsequently confirmed the expression of Bax and Bcl-2 in H520 cells was substantially regulated by silver NPs. We also demonstrated that silver NPs induced the cleavage of apoptosis-related proteins, poly (ADP-ribose) polymerase and caspase-3. In this study, we suggest that silver NPs induce apoptosis in H520 cells by regulation of CREB signaling pathways and may be useful as a therapeutic strategy for cancer.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A18.
Abstract A20: Evidences that GPR43, a G-protein-coupled receptor for short chain fatty acids, suppresses colon cancer
Authors: Tang Yong , Chen Yakun , Jiang Hongmei , Robbins Gregory , Nie Daotai
Published: January 2011

GPR43 is a G protein-coupled receptor for short chain fatty acids (SCFAs). Expression of GPR43 is detected in hematopoietic tissues and the large intestine. SCFAs are derived from bacterial fermentation and metabolism of undigested dietary fibers and have been recognized for their cancer prevention activities in the colon. The role of SCFAs, particularly butyrate, in colon cancer therapy has been extensively studied, and its tumor suppressive functions are believed to be due to their intracellular actions, notably inhibition of histone deacetylase. In this study, we show that SCFAs also exert their anti-tumor effects via receptor GPR43 and that GPR43 is frequently lost in colon cancer cells. Immunohistostaining revealed that GPR43 immunoreactivity was high in normal colon tissues (N=31) but was markedly reduced or completely lost in most colorectal adenocarcinoma tissues (N=70) and their corresponding lymph node metastatic adenocarcinomas (N =38). RT-PCR analysis detected the presence of full length GPR43 mRNA in only one (HT-29) out of nine established human colon cancer cell lines. Restoration of GPR43 expression in HCT8 human colonic adenocarcinoma cells induced G0/G1 cell cycle arrest and activated caspases, leading to increased apoptotic cell death after propionate/butyrate treatment. Restored GPR43 expression, coupled with propionate treatment, induced an upregulation of p21 and a decrease in the levels of cyclin D3 and cyclin-dependent kinases (CDKs) 1 and 2, while the CDK4 and CDK6 levels remained unchanged. Our results suggest that GPR43 functions as a tumor suppressor by mediating SCFA-induced cell proliferation inhibition and apoptotic cell death in colon cancer.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A20.
Abstract A26: Impact of PARP1 on AR signaling and therapeutic response in prostate cancer
Authors: Schiewer Matthew J. , Goodwin Jonathan , Knudsen Karen A.
Published: January 2011

Poly (ADP-ribose) polymerase 1 (PARP1) modifies various nuclear proteins by poly (ADP-ribose)-ylation, and has a known role in a multitude of chromatin-associated functions, including: transcriptional coregulation, modification of chromatin structure, regulation of insulators, and well-established activities in DNA repair. With regard to nuclear receptors, PARP1 promotes recruitment of topoisomerase IIβ (TopoIIβ) to estrogen-regulated promoters, leading to promoter DNA cleavage, factor exchange, and transcriptional activation. However, PARP1 function is known to be context dependent. Here, the impact of PARP1 on AR signaling was assessed under conditions of prostate cancer relevance. As will be discussed, key preliminary data strongly suggest that PARP1 function is critical for the pro-tumorigenic functions of AR. First, pharmacological inhibition of PARP1 enzymatic activity potently suppressed ligand-dependent AR transcriptional activity on target genes of clinical relevance. As it is well established that AR is involved in all stages of disease, PARP inhibition could potentially serve to prevent progression. Second, the mechanism of PARP1-mediated AR regulation appears to be manifest at the level of chromatin, as inhibition of PARP1 failed to alter AR protein levels. This was assessed by chromatin immunoprecipitation assays to delineate the impact on AR signaling. Third, it was shown that suppression of PARP1 specifically inhibited AR-dependent prostate cancer cell proliferation in both early stage and late stage (castrate-resistant) models of disease. This observation could potentially lead to studies to determine if PARP inhibition can prevent the transition to castrate resistance, as there is some evidence that PARP inhibition can decrease relapse in models of mammary tumors. Lastly, it was observed that PARP1 inhibition cooperates with currently used genotoxic therapeutic modalities (IR and Docetaxel) in reducing cell survival, dependent on treatment scheduling. In sum, our data identify PARP1 as a critical effector of AR activity at the level of chromatin, and suggest that abrogation of PARP1 function may cooperate with existing therapeutics to improve the response to therapeutic intervention and may serve as a means to prevent disease progression.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A26.
Abstract A3: Urinary cadmium and mammographic density in premenopausal women
Authors: Adams Scott V. , Newcomb Polly A. , Shafer Martin M. , Atkinson Charlotte , Bowles Erin J. Aiello , Newton Katherine M. , Lampe Johanna W.
Published: January 2011

Background: Mammographic density (MD), a strong marker of breast cancer risk, is influenced by genetic, environmental, and hormonal factors. Cadmium, a persistent and widespread environmental pollutant, has been associated with risk of breast cancer, and laboratory evidence suggests cadmium is a carcinogen in the breast. Urinary cadmium concentration is a measure of exposure to cadmium over a prior 20-30 years.

Methods: In a cross-sectional study of MD and urinary cadmium concentration, percentage MD (MD%) and Breast Imaging-Reporting and Data Systems (BI-RADS) density category were determined from screening mammograms of 190 premenopausal women ages 40-45 years recruited from a breast cancer screening program at a large integrated healthcare system. Women completed a health questionnaire, and the cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and corrected for urine creatinine. Multivariable linear regression and logistic regression were used to estimate the strength of association between urinary cadmium and mammographic breast density, adjusted for age, parity, smoking history, race, and body mass index.

Results: Adjusted mean MD% among women in the upper tertile of creatinine-corrected urine cadmium was 4.6% higher (95% confidence interval (CI): −2.3 to 11.6%) than in women in the lowest cadmium tertile. Each twofold increase in urine cadmium was associated with higher odds of MD% in the upper tertile (odds ratio (OR): 1.29, 95% CI: 0.82-2.02) or a BIRADS category rating of “extremely dense” (OR: 1.75, 95% CI: 1.14-2.70).

Conclusions: Exposure to cadmium may be associated with increased breast density in premenopausal women. These results support earlier findings that cadmium may increase risk of breast cancer.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A3.
Abstract A32: Identification and characterization of colon cancer-associated antigens
Authors: Broussard Elizabeth K. , Coveler Andrew , Slota Meredith , Jackson Emily , Bates Nicole , Higgins Doreen , Childs Jennifer , Yang Yi , Disis Mary L.
Published: January 2011

Colon cancer (CRC) is an immunogenic tumor and adaptive immunity may play a role in inhibiting disease relapse. A vaccine to boost cellular immunity in CRC patients could prevent disease recurrence, but there have been few defined immunogenic proteins identified as vaccine candidates. TVG has shown that overexpressed tumor associated proteins, abundant in the cancer state but expressed at basal levels in normal cells, can be immunogenic. We hypothesized that ideal candidate antigens would be ones already validated as prognostic markers in multivariate analysis. We performed a directed literature review using search words e.g. colon cancer, prognosis, biomarker, multivariate analysis. We selected a panel of eight proteins based on (1) incidence of expression, (2) independent predictor of poor prognosis, (3) independent predictor of early disease recurrence, and (4) known biologic function in CRC pathogenesis. Using a web based algorithm program developed by TVG, we identified peptides that were predicted to be high affinity binders across multiple HLA DR alleles; characteristics we have shown to be associated with native epitopes of self tumor antigens. We selected and synthesized 19 peptides predicted to be the highest binders. We evaluated the potential immunogenicity of peptides with 1. IFN-g ELISPOT assays using PBMC from CRC patients and normal controls and 2. specific IgG antibody response with ELISA using sera from CRC patients and normal controls. We quantitated antigen gene expression using qPCR in cell lines representing microsatellite unstable (MSI), chromosome unstable (CIN) and CpG island methylator phenotype (CIMP) colorectal cancer. The eight proteins are: CDC25B, COX-2, EBAG9, EGFR, Fascin-1, IGF-1R, PRL-3 and VCP. Two of the eight proteins had already been shown to be human tumor antigens. For all candidate antigens there was a greater IFN-g response in CRC patients than in controls; for three proteins, this difference reached statistical significance. Six proteins were positive by ELISA. Seven antigen genes were overexpressed relative to normal colon. We conclude that: 1. biologically relevant CRC associated proteins can be identified that are associated with prognosis, 2. epitopes predicted to bind multiple DR alleles, derived from candidate antigens, elicit T cell responses greater in CRC patients than in normal controls, 3. there was an overexpression of candidate genes across three different CRC phenotypes, and 4. these antigens may represent novel immunologic targets for CRC.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A32.
Abstract A35: LDL induces prostate cancer cell growth and inhibits growth-reducing effects of simvastatin
Authors: Murtola Teemu J. , Syvälä Heimo , Pennanen Pasi , Bläuer Merja , Ylikomi Timo , Tammela Teuvo L.
Published: January 2011

Background: Several epidemiological studies have reported decreased risk of advanced prostate cancer among men using statins, a widely used group of cholesterol-lowering drugs. The association is possibly linked to serum LDL reduction during statin therapy. We studied in vitro the importance of LDL on growth of normal and cancerous prostate epithelial cells and evaluated its association with growth reducing effect of simvastatin.

Methods: Four normal prostatic epithelial cell lines (P96E, P97E, PWR-1E, RWPE-1) and two cancer cell lines (LNCaP and VCaP) were grown in cholesterol-free conditions. Cells were treated with 1 µg/ml, 15 µg/ml or 50 µg/ml LDL, 100 nM or 10 µM simvastatin and/or 100 µM mevalonate for seven days. Cellular growth rate was measured with crystal violet staining.

Results: In normal epithelial cells, 1 µg/ml and 15 µg/ml LDL did not have marked effect on cell growth, while 50 µg/ml LDL had a growth reducing effect. Conversely, in cancer cells cellular growth was stimulated in direct correlation with LDL concentration. Simvastatin at 100 nM concentration caused clear growth reduction in normal epithelial cells, and 10 µM simvastatin had a cytotoxic effect. Growth reduction by 100 nM simvastatin was attenuated by increasing LDL concentrations, the effect being completely reversed by 15 µg/ml LDL. However, the cytotoxic effect of 10 µM simvastatin could not be reversed by LDL alone, but required combination of 100 µM mevalonate and 15 µg/ml LDL.

Conclusions: Our results demonstrate the importance of LDL for prostate cancer cell growth. The growth reducing effect of simvastatin depends on the level of extracellular LDL. Our study supports the epidemiological studies suggesting that statins’ prostate cancer risk reducing effects depend on LDL reduction. Hypercholesterolemia could be a prostate cancer risk factor.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A35.
Abstract A41: Evaluation of maximum tolerated dose of aerosolized Rapamycin in A/J mice
Authors: Sharma Sheela , Lee Jin , Zhou Jianliang , Wong Brian , Steele Vernon E.
Published: January 2011

Rapamycin, an approved anti-rejection drug for organ transplantation, has shown antitumor activity in preclinical studies and clinical trials. However, concerns regarding the prevalence of pneumanitis in few patients receiving Rapamycin by injection have prompted us to pursue an alternative and hopefully less toxic route of administration. Previously, we have shown that there was a good correlation between the dose-dependent increase in blood levels of Rapamycin and corresponding dose-dependent decrease in the activity of two biomarkers (phospho-AKT and mTOR) in the mouse lung. We have also observed that there was no significant difference between continuous or intermittent dosing regimens in reducing p-AKT and mTOR activity by rapamycin as the activity levels continued to remain suppressed (60 % inhibition) for up to 3 days after the last exposure. The objective of the current study is to assess the maximum tolerated dose (MTD) of aerosolized rapamycin to select optimal doses for subsequent cancer prevention studies. Female A/J mice (8 wks old) were exposed to 3 different doses (0.1, 1 and 10 mg/kg — equivalent to 1.6, 15.8 and 158 mg/m3 of air, respectively) of rapamycin by Nose-Only inhalation for 1 hr/day, 3 days (every other day) per week for 6 weeks. No toxicity was observed during or after the exposure in all dose groups except that the animals exposed to 10 mg/kg of rapamycin showed relatively slow body weight gain compared to other dose groups. Hematology of whole blood showed no significant difference among different dosing groups. Lymphocyte subpopulation evaluated by flow cytometry in blood showed that rapamycin at all doses had no effect on the ratio of T-helper cells/cytotoxic T-cells (CD4+/CD8+). Also, rapamycin did not affect the number of T regulatory cells, which was assessed by measuring FoxP3+/CD3+ ratio (4-5% in all groups) in lungs processed for immunohistochemistry. Pathological evaluation of H&E stained lung sections did not find any dose-related abnormalities in all groups. In conclusion, this study showed that rapamycin did not cause any toxicity in mice exposed to rapamycin by inhalation for 6 weeks at the dose ranges tested, indicating that rapamycin via inhalation route could be a safe candidate as a chemopreventive agent against lung tumors (Supported by NCI #N01-CN-53301).

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A41.
Abstract A45: Berberine acts as an antagonist to estradiol-induced proliferation by inducing apoptosis in cervical cancer cells
Authors: Komal Komal , Sharma Alpana , Deshwal Vishal Kumar
Published: January 2011

Background: Cervical cancer is the most common cancer in Indian females and is associated with infection with high-risk human papillomaviruses (HPVs). Prolonged use of oral contraceptives has been established as a risk factor for cervical cancer which is mediated by elevated estradiol level. Berberine has emerged as a potential anticancer agent in various cancers. The present study investigated the effect of bereberine on estradiol pretreated cervical cancer cell lines HeLa, SiHa and C33A.

Methods: Cervical cancer cells were cultured in DMEM/RPMI/MEM medium supplemented in 10% FBS in a humidified atmosphere of 95% air and 5% CO2 at 37°C and were treated with estradiol for 24 hr followed by 50 µM and 75 µM Berberine for 24 hrs standardized using MTT assay. Apoptosis was measured by flow cytometery. Telomerase activity was studied using PCR ELISA. The expression of various proliferation proteins like PCNA, p16 was assessed by ICC. Expression of viral oncoprotein E6 and E7, Cyclin D1, p53 was assessed by Western blotting.

Results: Treatment of cervical cancer cells with estradiol resulted in increased proliferation after 24 hrs in HPV positive cell lines HeLa and SiHa but no proliferation was observed in HPV negative cell line C33A. Elevation of telomerase activity, viral oncoprotein E6 and E7, PCNA, p16 and cyclin D1 was seen in HPV positive cell lines on pretreatment by estradiol, On the other hand after post treatment by berberine for 24 hrs levels of E6, E7, PCNA and cyclin D1 were reduced while the level of telomerase and p16 were unaltered. Furthermore, estradiol pretreated HPV negative cell line C33A on treatment by berberine shows reduction in level of telomerase, PCNA, p16 and activation of p53 tumor suppressor protein, thus demonstrating the importance of HPV viral proteins in estradiol-induced carcinogenesis.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A45.
Abstract A46: Pseudohypericin in Hypericum perforatum inhibited LPS-stimulated PGE2 and NO in mouse macrophages by potentiating SOCS3 expression
Authors: Huang Nan , Hauck Cathy , Rizshsky Ludmila , Murphy Patricia A. , Nikolau Basil J. , Birt Diane F.
Published: January 2011

Introduction: Hypericum perforatum, also known as ‘St. John's wort’, is one of the most studied medicinal plants. Despite its primary use as an anti-depression agent, certain compounds such as hypericin and hyperforin in H. perforatum extract have been shown to inhibit tumor growth by inducing apoptosis/necrosis and inhibiting angiogenesis. Using hypericin in photodynamic cancer therapy is also being studied. Our previous studies have demonstrated that H. perforatum extract and a group of 4 compounds in it, namely pseudohypericin, amentoflavone, quercetin, and chlorogenic acid, decreased lipopolysaccharide (LPS)-stimulated macrophage inflammatory response, and identified the activation of suppressor of cytokine signaling 3 (SOCS3) as a candidate mechanism for this activity. Given that both inflammation and SOCS3 suppression are associated with tumor progression, we studied the role of SOCS3 activation in the anti-inflammatory activity of H. perforatum extract and its components.

Methods: Specific siRNA was used to knockdown the expression of SOCS3 in RAW 264.7 mouse macrophages. Activation of SOCS3 in macrophages was measured at mRNA and protein levels using qRT-PCR and Western blot. H. perforatum extract at 30 µg/mL, the 4 compounds at the same concentrations as in the extract, and the combinations of individual compounds were applied to macrophages with and without SOCS3 knockdown to reveal whether their inhibition of LPS-stimulated prostaglandin E2 (PGE2) and nitric oxide (NO) was dependent on SOCS3.

Results: SOCS3 expression in the mouse macrophages was activated upon LPS stimulation and further potentiated by H. perforatum extract and the 4 compounds studied. SOCS3 siRNA transfection significantly compromised the activation of SOCS3. H. perforatum extract and the 4 compounds reduced LPS-stimulated PGE2 and NO production, but only the inhibitory effect of the 4 compounds was negated by SOCS3 knockdown. Combinations of two or three of the 4 compounds that include pseudohypericin, the most essential component among the four that act synergistically in reducing macrophage inflammatory response, lost their inhibitory effect on PGE2 and NO production in SOCS3 knockdown cells.

Conclusions: SOCS3 activation was critical for pseudohypericin's independent and interactive anti-inflammatory activity with amentoflavone, quercetin, and chlorogenic acid. H. perforatum extract utilized alternative mechanisms that are SOCS3 independent to inhibit macrophage inflammation. In addition to light-activated cytotoxicity and inhibition of angiogenesis, magnification of SOCS3 activation by H. perforatum extract might contribute to its anti-tumor potential.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A46.
Abstract A49: Verification of two novel phytochemical inducers of phase II metabolic enzyme NQO1 in human lung cells
Authors: Marquardt Gaby , Tan Xianglin , Spivack Simon D.
Published: January 2011

One strategy for lung cancer chemoprevention focuses on the use of agents to modulate the metabolism and disposition of tobacco, environmental and endogenous carcinogens through up-regulation of detoxifying phase II enzymes. However, in studies to date, most candidate agents are not active in human lung cells. Therefore we previously applied a gene expression-based high-throughput screening approach to investigate n=800 plant-derived polyphenolic- and flavenoid- predominant compounds in the MicroSource Natural Products Library as to their effect on inducing the phase II metabolic enzymes glutathione S-transferases (GSTP1) and NAD(P)H:quinone oxidoreductase 1 (NQO1) in primary normal human bronchial epithelial (NHBE) cells and immortalized human bronchial epithelial cells (HBEC). We had identified 2, 3-dihydroxy-4-methoxy-4’-ethoxybenzophenone (DMEBP, putative source arctic sponge) and triacetylresveratrol (TRES, putative source plant myrtle) as new inducers for NQO1 mRNA expression. In the current study, in order to confirm our results, NHBE and HBEC cells in culture were exposed to diet-achievable levels of TRES and DMEBP (0.5, 1.0, 2.0 µM), as well as a panel of conventionally-recognized phytopreventive agents [epigallocatechin gallate (EGCG), resveratrol (RES) and sulforaphane (SFN)] for 24 h, 48 h, and 6 d, respectively. Quantitative RNA-specific RT-PCR showed an up-regulation of NQO1 mRNA expression of up to 10.8 fold in DMEBP-treated NHBE cells and an up-regulation of up to 4.6 fold in TRES-treated NHBE cells. NQO1 protein expression increased up to 3.4 fold in DMEBP-treated and up to 1.8 fold in TRES-treated NHBE cells. HBEC cells showed similar results for mRNA expression — an up-regulation of NQO1 mRNA expression of up to 9.7 fold in DMEBP-treated HBEC cells and an up-regulation of up to 3.1 fold in TRES-treated HBEC cells — whereas none of the tested compounds had an effect on protein expression in HBEC cells. DMEBP had a narrow therapeutic window, and was notably toxic to lung cells at 1-2 µM. We then measured accumulation of reactive oxygen species (ROS) in NHBE cell using DFA, and total GSH assays. Our ROS data so far show a slight anti-oxidant effect for DMEBP, but no effect yet found for TRES. Our data show two new agents have some effect on the up-regulation of the detoxifying enzyme NQO1 at mRNA and protein levels, but the effect was modest, and none was observed for GSTP1. Among the newly discovered agents, TRES is the most plausible candidate resulting from this search, and compares favorably, to conventional plant-derived polyphenolics/flavenoids tested.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A49.
Abstract A51: Acacetin in inhibiting tumor growth and angiogenesis
Authors: Jiang Bing-Hua , Liu Ling-Zhi , Jiang Lisa , Jing Yi , Jiang Xiue
Published: January 2011

Background: Acacetin (5,7-dihydroxy-4′-methoxyflavone) is a member of the flavonoid compound familys, some of which have anti-cancerous effects. Angiogenesis is a key process during carcinogenesis and tumor growth; however, but the effect and the mechanisms of acacetin on angiogenesis and tumor growth remain to be elucidated.

Methods: In order to determine the effect of acacetin on the expression of vascular endothelial growth factor (VEGF) and HIF-1α expression, we tested VEGF expression by reporter assay and HIF-1α expression by Western blotting and RT-PCR assay. To test whether overexpression of active form of AKT increases HIF-1 expression, transient transfection was performed. Tumor angiogenesis and tumor formation in vivo were examined by chicken chorioallantoic membrane (CAM).

Results: Acacetin decreased the steady level of VEGF mRNA under the normoxia and hypoxia conditions while inhibiting, and inhibited VEGF transcriptional activation. To further determine the potential mechanism of acacetin in inhibiting VEGF expression, we showed demonstrated that acacetin inhibited HIF-1α expression and AKT activation. Overexpression of HIF-1α or AKT abolished acacetin-decreasing VEGF transcriptional activation, indicating that AKT and HIF-1 are the essential downstream targets of acacetin for inhibiting VEGF expression in the cells. Moreover, acacetin significantly inhibited ovarian cancer cells-induced angiogenesis and tumor growth in vivo through inhibiting HIF-1α and VEGF expression. Acacetin inhibited HIF-1α protein expression through increasing its degradation and decreasing its stability, but did not alter HIF-1α mRNA levels.

Conclusion: These results indicate that acacetin inhibits tumor agnigenensis and growth by blocking the AKT/HIF-1/VEGF pathway. It may be a useful natural compound for cancer prevention and treatment.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A51.
Abstract A56: Induction of spermine oxidase by enterotoxigenic Bacteroides fragilis contributes to tumorigenesis in a model of colitis-associated colorectal cancer
Authors: Goodwin Andrew , Wu Shaoguang , Huso David , Wu Xinqun , Hicks Jessica , Shields Christina Destefano , Hacker-Prietz Amy , Rabizadeh Shervin , Marzo Angelo De , Sears Cynthia , Casero Robert
Published: January 2011

It is estimated that the etiology of 20-30% of epithelial cancers is directly associated with inflammation, though the molecular events linking inflammation and the necessary carcinogenic mutations remain to be clarified. In the context of gastrointestinal disease, the bacterial pathogens Helicobacter pylori and enterotoxigenic Bacteroides fragilis (ETBF) are significant sources of chronic inflammation and have been implicated as risk factors for the development of gastric and colorectal cancer, respectively. We have previously demonstrated that H. pylori and the cytokine tumor necrosis factor-α (TNF-α) rapidly induce spermine oxidase (SMO), resulting in increased cellular reactive oxygen species (ROS) and DNA damage, in gastric and lung epithelial cells. In addition, tissue microarray studies revealed that increased SMO expression was associated with prostatic intraepithelial neoplasia and prostate cancer lesions and that benign prostate epithelial tissue from men with these diseases exhibits higher SMO expression than normal controls. We now demonstrate that purified B. fragilis toxin (BFT) upregulates SMO in HT29/c1 and T84 colonic epithelial cells, resulting in SMO-dependent induction of γ-H2A.x, a marker of DNA damage. Further, ETBF-induced colitis in wild-type or APC+/− Min C57Bl/6 mice is associated with increased SMO expression. Inhibition of SMO activity by MDL 72,527 in vivo (20 mg/kg i.p. 3 days per week) significantly reduces ETBF-induced chronic inflammation, proliferation, and induction of Th17-associated cytokines. Most importantly, in Min mice, treatment with the SMO inhibitor reduces ETBF-induced colon tumorigenesis by 69% (p<.001). Our studies suggest that SMO is a novel target for chemopreventive or chemotherapeutic drug development.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A56.
Abstract A61: Circulating adiponectin levels as a predictive factor of breast cancer in a double-blind 2x2 phase II trial of low-dose tamoxifen and fenretinide for breast cancer prevention
Authors: Aliana Guerrieri-Gonzaga , Gandini Sara , Johansson Harriet , Macis Debora , Magni Paolo , Dozio Elena , Lazzeroni Matteo , Gulisano Marcella , Latronico Antuono , Bonanni Bernardo , Decensi Andrea
Published: January 2011

Background: The assessment of breast cancer risk is a key step for an effective preventive treatment. Besides the established risk assessment models, independent predictive factors like circulating biomarkers may also be important to better select high risk subjects and to determine efficacy of chemopreventive treatment.

Adiponectin is a peptide hormone secreted from the adipose tissue with anti-inflammatory, anti-atherogenic and anti-diabetic properties. Epidemiological studies have shown that plasma adiponectin level is inversely related to breast cancer risk.

In the present study, we measured plasma adiponectin levels in premenopausal women participating in a phase II trial of low-dose tamoxifen and fenretinide for breast cancer prevention.

Methods: Premenopausal women (n = 235) were randomly assigned in a double-blind 2x2 trial to receive tamoxifen 5 mg/d, fenretinide, a vitamin A derivative, 200 mg/d, both agents, or placebo for 2 years. A total of 181 premenopausal women with ductal intraepithelial neoplasia (DIN) and 54 unaffected women at higher risk according to the Gail model were enrolled.

Mammographic percent density was centrally measured using the computer-assisted method described by Boyd. Plasma adiponectin was measured by use of a commercial enzyme-linked immunosorbent assay kit.

Preliminary results: According to disease status (DIN vs Gail) at baseline, median plasma adiponectin levels were lower in women with a DIN (10 ug/ml; interquartile (IQ) range: 7.1-14) compared to unaffected women with a Gail risk (12 ug/ml; IQ range: 8.7-14.7) (p=0.05).

Importantly, after a median follow-up of 5.5 years, plasma adiponectin levels were lower in women who had a breast cancer event (7.7 ug/mL; IQ range: 6.46-12.78) compared to women without event (11.02 ug/mL; IQ range: 7.8-14.4) (p=0.015). This difference is also maintained after adjusting for BMI and treatment allocation (p=0.011).

Considering the distribution of adiponectin levels at baseline, we observed a 9% reduction in the hazard ratio of breast cancer events by each unit increase of adiponectin levels (95%CI: 0.83-0.96; p=0.02, cox model adjusted for BMI, treatment allocation, mammographic density and disease status at baseline).

Conclusion: We found that subjects with lower plasma adiponectin levels had a significantly higher risk of breast cancer event. The association appeared independent of known risk factors such as BMI and mammographic breast density. Further studies to better understand and confirm the role of adiponectin as independent predictive risk factor are warranted.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A61.
Abstract A85: Fruit and vegetable consumption reduces the risk of pancreatic cancer
Authors: Jansen Rick J. , Robinson Dennis P. , Stolzenberg-Solomon Rachael Z. , Bamlet William R. , de Andrade Mariza , Oberg Ann L. , Hammer Traci J. , Rabe Kari G. , Olson Janet E. , Anderson Kristin E. , Sinha Rashmi , Petersen Gloria M.
Published: January 2011

Pancreatic cancer is a devastating disease for which the role of dietary risk factors remains inconclusive. We evaluated fruit, vegetable, fiber, and grain consumption with pancreatic cancer risk using a clinic-based case-control design, excluding participants who reported changing their diet within 5 years prior to entering the study. Our study included 384 rapidly ascertained cases and 983 non-cases (frequency matched on age at time of recruitment (± 5 years), race, sex, and region of residence) who completed epidemiologic surveys and a 144-item food frequency questionnaire developed by the National Cancer Institute. Logistic regression was used to calculate odds ratios (OR) and 95% CIs, adjusted for age, sex, smoking, body mass index, energy intake, and alcohol consumption. Comparing highest to lowest quintiles, we observed significant (OR < 0.01) inverse associations with significant trends (ptrend < 0.01) for citrus, melon, and berries, other fruit, dark green vegetables, deep yellow vegetables, tomato, other vegetables, dry bean and pea, insoluble fiber, soluble fiber, and whole grains. Adjusting for diabetes or total sugar intake in the multivariate logistic regression model did not significantly affect results. Consuming a diet high in fruits, vegetables, fiber, and whole grains may reduce the risk of developing pancreatic cancer.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A85.
Abstract A86: Higher micronutrient intake is associated with human papillomavirus-positive head and neck cancer: A case-only analysis
Authors: Arthur Anna E. , Duffy Sonia A. , Sanchez Gloria I. , Gruber Stephen B. , Terrell Jeffrey E. , Hebert James R. , Bradford Carol R. , D'Silva Nisha J. , Carey Thomas E. , Wolf Gregory T. , Peterson Karen E. , Rozek Laura S. ,   UM Head and Neck SPORE Program
Published: January 2011

While tobacco and concurrent alcohol use account for the majority of head and neck squamous cell carcinomas (HNSCC), human papillomavirus (HPV)-16 contributes to a distinct subtype of the disease. HPV-positive HNSCC cases have better prognoses and typically occur in younger individuals with lower exposure to tobacco and alcohol and higher socioeconomic status (SES) when compared to those with more strongly tobacco-related, HPV-negative HNSCC. As dietary quality is associated with SES, patients with HPV-positive tumors also may have higher intake of micronutrients. This study was conducted to better understand the relationship between diet and HPV status among HNSCC patients. Subjects were recruited from two clinical centers participating in the University of Michigan Head and Neck Specialized Program of Research Excellence (SPORE). HPV genotyping was performed in DNA extracted from micro-dissected tissue and epidemiologic and dietary data collected. Multivariable logistic regression tested whether pretreatment consumption of 12 selected micronutrients was significantly associated with HPV status in 143 patients newly diagnosed with cancer of the oral cavity or pharynx. After controlling for age, sex, body mass index, tumor site, cancer stage, problem drinking, smoking and energy intake, a significant and positive association was observed between HPV-positive status and increasing quartiles of vitamin A, vitamin E, iron, β-carotene and folate intake (Ptrend<0.05). Patients with HPV-positive cancers have higher intakes of selected micronutrients compared to patients with HPV-negative tumors, suggesting that diet may be a factor in the improved prognosis documented in those with HPV-positive HNSCC. Dietary differences by HPV status should be considered in prognostic studies to better understand the influence of diet on HNSCC survival.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A86.