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Rosalind B Penney,1 Abbie Lundgreen,2 Aiwei Yao-Borengasser,3 Vineetha K Edavana,3 Suzanne Williams,3 Ishwori Dhakal,4 Roger K Wolff,2 Susan Kadlubar,3 Martha L Slattery2 1Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR, 2Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT, 3Division of Medical Genetics, University of Arkansas for Medical Sciences, Little Rock, AR, 4Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, AR, USA Background: Estrogen is known to decrease the risk of colon cancer in postmenopausal women, and may exert its actions by decreasing interleukin-6 (IL6) production via stabilization of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). Estrogens are biosynthesized by CYP19A1 (aromatase), so it is possible that genetic variations in CYP19A1 influences the risk of colon cancer by altering expression of CYP19A1. Further, studies on gene-gene interactions suggest that single nucleotide polymorphisms in one gene may affect expression of other genes. The current study aims to explore the role of CYP19A1 single nucleotide polymorphisms on CYP19A1, NFκB1 and IL6 gene expression. Methods: Phenotype–genotype associations, cross-associations between genes, and haplotype analyses were performed in both normal human colon (n=82) and liver (n=238) samples. Results: CYP19A1 rs10459592, rs1961177, and rs6493497 were associated with CYP19A1 expression in colon samples (P=0.042, P=0.041, and P=0.013, respectively). CYP19A1 single nucleotide polymorphisms (rs12908960, rs730154, rs8025191, and rs17523880) were correlated with NFκB1 expression (P=0.047, P=0.04, P=0.05, and P=0.03, respectively), and CYP19A1 rs11856927, rs2470152, and rs2470144 (P=0.049, P=0.025, P=0.047, respectively) were associated with IL6 expression in the colon. While rs730154 and rs17523880 could not be analyzed in the liver samples, none of the other associations with the colon were replicated in the liver samples. Haplotype analysis revealed three separate haplotypes of the CYP19A1 single nucleotide polymorphism that were significantly associated with CYP19A1, NFκB1, and IL6 gene expression. Conclusion: CYP19A1 single nucleotide polymorphisms are associated not only with CYP19A1 expression but also with NFκB1 and IL6 expression. These data demonstrate the possible functional consequences of genetic variation within the CYP19A1 gene on other genes in a biologically plausible pathway.Keywords: CYP19A1, NFκB1, interleukin-6, single nucleotide polymorphism, colon, liver

Rosalind B Penney,1 Abbie Lundgreen,2 Aiwei Yao-Borengasser,3 Vineetha Koroth-Edavana,3 Suzanne Williams,3 Roger Wolff,2 Martha L Slattery,2 Susan Kadlubar3 1Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR, 2Department of Internal Medicine, University of Utah Health Sciences Center, Salt Lake City, UT, 3Division of Medical Genetics, University of Arkansas for Medical Sciences, Little Rock, AR, USA Abstract: There are a number of in silico programs that use algorithms and external web sources to predict the effect of single nucleotide polymorphisms (SNPs). While many of these programs have been shown to predict accurately the effect of SNPs in functional areas of the gene, such as 5΄ upstream or coding regions, empiric research may be warranted to confirm the functional consequences of SNPs that are predicted to have little to no effect. We compared predictions from FASTSNP (Function Analysis and Selection Tool for Single Nucleotide Polymorphism) and F-SNP (Functional Single Nucleotide Polymorphism) with experimentally derived genotype-phenotype correlations to determine the accuracy of these programs in predicting SNP functionality. We used normal colon tissue to evaluate 24 TagSNPs within six genes. Two of 16 SNPs that were predicted to have no functional effect in FASTSNP were significantly associated with gene expression. Only one of the eight SNPs that were predicted to have a low to high effect was significantly associated with gene expression. While the two in silico programs that were used were similar in their results for the SNPs predicted by FASTSNP to have no effect, of SNPs with scores from low to high, there were three that received an F-SNP score below what is considered functionally significant. In silico programs can fail to identify functional SNPs, supporting a continuing role for empiric analysis of SNP function. Laboratory analysis is necessary to identify causal SNPs accurately, establish biological plausibility of the effect, and ultimately inform cancer prevention strategies. Keywords: in silico prediction, colon, single nucleotide polymorphisms

Xuemei Zhang,1 Maosheng Huang,2 Xifeng Wu,2 Susan Kadlubar,1 Jie Lin,2 Xinfeng Yu,1 Chunyang Fan,3 Baitang Ning,4 Fred F Kadlubar1†1University of Arkansas for Medical Sciences, Little Rock, Arkansas, 2The University of Texas MD Anderson Cancer Center, Houston, Texas, 3VA hospital, Little Rock, Arkansas, 4National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA†Fred F Kadlubar passed away on December 4, 2010.Abstract: The objective of this study was to determine copy number variant (CNV) and promoter genetic variants in glutathione S-transferase Mu class 1 (GSTM1) and the risk of recurrence (REC)/second primary tumor (SPT) in patients with previously diagnosed early stage head and neck cancer. Among 441 subjects, 133 experienced REC and/or an SPT, while 308 had single primary disease. TaqMan real-time polymerase chain reaction was used to measure the exact copy number of GSTM1 and direct sequencing was used to determine genetic variants in the GSTM1 promoter region. Multivariate Cox regression analysis was performed to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) associated with copy number and genetic variants. REC/SPT-free survival times were compared by constructing Kaplan–Meier curves and differences between curves were tested by logrank test. Results showed a significantly decreased REC/SPT (HR = 0.57; 95% CI = 0.35–0.95) and longer REC/SPT-free survival in subjects with at least two copies of GSTM1 compared with the GSTM1 homozygous deletion, but not in those with one copy of GSTM1. The −498G, −426G, and −339T alleles were significantly associated with REC/SPT, with HRs of 0.11 (0.02–0.85), 0.28 (0.11–0.74) and 2.02 (1.07–3.82), respectively. Kaplan–Meier survival analysis showed that the −498G, −426G, and −339C alleles were also significantly associated with increased REC/SPT-free survival. Further haplotype analysis showed the haplotype P-498G--426G--339C carriers had decreased REC/SPT with a HR of 0.09 (95% CI 0.01–0.71) and increased REC/SPT-free survival compared with those with haplotype P-498C--426A--339T. The P-498C--426A--339T-containing reporter construct had significantly increased luciferase expression. These results suggest that the GSTM1 CNV and promoter haplotype are better predictors of REC/SPTs of head and neck cancer than just measuring the presence/absence of GSTM1.Keywords: GSTM1, copy number variant, REC, SPT, single nucleotide polymorphism

Xinfeng Yu,1 Takahiro Kubota,2 Ishwori Dhakal,1 Setsuo Hasegawa,3 Suzanne Williams,1 Shogo Ozawa,4 Susan Kadlubar11Division of Medical Genetics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA; 2Chiba Institute of Science, Chiba, Japan; 3Sekino Clinical Pharmacology Clinic, Tokyo, Japan; 4Iwate Medical University, Iwate, JapanAbstract: Sulfotransferase isoform 1A1 (SULT1A1) plays a key role in the metabolism of a variety of endo- and xenobiotics and it's activity could influence response to drugs. Our previous studies have focused on the impact of genetic variants of SULT1A1 on enzymatic activity in Caucasians and African-Americans. However, the contribution of genetic variants to SULT1A1 activity in Asians has not been explored. In this study, we investigated the collective effects of both SULT1A1 copy number variants (CNVs) and single nucleotide polymorphisms (SNPs) in the promoter region, coding region, and 3´ untranslated region on SULT1A1 activity in Japanese subjects. SNPs in the SULT1A1 promoter and 3´ untranslated region were not associated with SULT1A1 activity (P > 0.05). SULT1A1*1/2 (Arg213His) was marginally associated with SULT1A1 activity (P = 0.037). However, SULT1A1 CNVs were strongly associated with SULT1A1 activity (trend test P = 0.008) and accounted for 10% of the observed variability in activity for Japanese subjects. In conclusion, SULT1A1 CNVs play a pivotal role in determination of SULT1A1 activity in Japanese subjects, highlighting the influence of ethnic differences in SULT1A1 genetic variants on drug metabolism and therapeutic efficacy.Keywords: CNV, genotype, phenotype, SULT1A1, single nucleotide polymorphisms

Vineetha Koroth Edavana1, Xinfeng Yu1, Ishwori B Dhakal1, Suzanne Williams1, Baitang Ning2, Ian T Cook3, David Caldwell1, Charles N Falany3, Susan Kadlubar11Division of Medical Genetics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA; 2Division of Personalized Nutrition and Medicine, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, USA; 3Department of Pharmacology, University of Alabama, Birmingham, AL, USAAbstract: Fulvestrant (Faslodex™) is a pure antiestrogen that is approved to treat hormone receptor-positive metastatic breast cancer in postmenopausal women. Previous studies have demonstrated that fulvestrant metabolism in humans involves cytochromes P450 and UDP-glucuronosyltransferases (UGTs). To date, fulvestrant sulfation has not been characterized. This study examined fulvestrant sulfation with nine recombinant sulfotransferases and found that only SULT1A1 and SULT1E1 displayed catalytic activity toward this substrate, with Km of 4.2 ± 0.99 and 0.2 ± 0.16 µM, respectively. In vitro assays of 104 human liver cytosols revealed marked individual variability that was highly correlated with β-naphthol sulfation (SULT1A1 diagnostic substrate; r = 0.98, P < 0.0001), but not with 17ß-estradiol sulfation (SULT1E1 diagnostic substrate; r = 0.16, P = 0.10). Fulvestrant sulfation was correlated with both SULT1A1*1/2 genotype (P value = 0.023) and copy number (P < 0.0001). These studies suggest that factors influencing SULT1A1/1E1 tissue expression and/or enzymatic activity could influence the efficacy of fulvestrant therapy.Keywords: fulvestrant, sulfotransferase, genotype, copy number

Abstract Background In estrogen responsive MCF-7 cells, estradiol (E2) binding to ERα leads to transcriptional regulation of genes involved in the control of cell proliferation and survival. MicroRNAs (miRNAs) have emerged as key post-transcriptional regulators of gene expression. The aim of this study was to explore whether miRNAs were involved in hormonally regulated expression of estrogen responsive genes. Methods Western blot and QPCR were used to determine the expression of estrogen responsive genes and miRNAs respectively. Target gene expression regulated by miRNAs was validated by luciferase reporter assays and transfection of miRNA mimics or inhibitors. Cell proliferation was evaluated by MTS assay. Results E2 significantly induced bcl-2, cyclin D1 and survivin expression by suppressing the levels of a panel of miRNAs (miR-16, miR-143, miR-203) in MCF-7 cells. MiRNA transfection and luciferase assay confirmed that bcl-2 was regulated by miR-16 and miR-143, cyclinD1 was modulated by miR-16. Importantly, survivin was found to be targeted by miR-16, miR-143, miR-203. The regulatory effect of E2 can be either abrogated by anti-estrogen ICI 182, 780 and raloxifene pretreatment, or impaired by ERα siRNA, indicating the regulation is dependent on ERα. In order to investigate the functional significance of these miRNAs in estrogen responsive cells, miRNAs mimics were transfected into MCF-7 cells. It revealed that overexpression of these miRNAs significantly inhibited E2-induced cell proliferation. Further study of the expression of the miRNAs indicated that miR-16, miR-143 and miR-203 were highly expressed in triple positive breast cancer tissues, suggesting a potential tumor suppressing effect of these miRNAs in ER positive breast cancer. Conclusions These results demonstrate that E2 induces bcl-2, cyclin D1 and survivin by orchestrating the coordinate downregulation of a panel of miRNAs. In turn, the miRNAs manifest growth suppressive effects and control cell proliferation in response to E2. This sheds a new insight into the integral post-transcriptional regulation of cell proliferation and survival genes by miRNAs, a potential therapeutic option for breast cancer.

Vascular endothelial growth factor (VEGF) is a central mediator of angiogenesis in breast cancer. We have conducted a clinical trial using bevacizumab (B) in breast cancer in the neoadjuvant setting and showed improved pathologic complete response (pCR) when B was added to chemotherapy (CT). 41% of patients (Pts) who received B+CT achieved pCR. Blood and tumor samples were collected at baseline and serially on treatment from 39 patients who participated in the study. The correlative study was approved by the IRB and consent forms were obtained at the time of enrollment. Since patients do not equally benefit from B, it has become necessary to define the profile of patients who will benefit and those who are more likely to have major side effects from the drug. This study was conducted to evaluate for the presence of specific SNPs and CNV in the germ line and a serum protein profile that might be predictive of pCR in the neoadjuvant setting in breast cancer patients receiving B and CT. Methods: To test for the presence of functional germ line SNPs and CNVs that may influence pCR, DNA was extracted from buffy coats of study participants and SNPs/CNVs were determined using Illumina technology. To test the hypothesis that individuals who achieved pCR were those with differential expression of selected proteins in their blood, custom multiplex was performed for the following serum proteins: ANG-1, ANG-2, bFGF, IL -1a, MMP-9, PDGF-BB, PECAM-1, Tie-2, VEGF, and VEGFR2. Statistical test: The association between genotype and CNV of each SNP vs. pCR status were analyzed using Cochran-Armitage Trend Test. Differences in serum protein levels between pCR and non-pCR groups were examined by Wilcoxon rank sum test. Significance of association was evaluated in two settings of α (I) α=0.05 (ii) α=0.00001. Results: Genotype and CNV vs. pCR (n = 38). In genotype vs. pCR status by SNPs tests, 131618 (-13%) SNPs with allele frequency <0.05 were excluded from the analysis. In CNV vs. pCR status by SNPs tests, only 46891 (4.6%) SNPs were analyzed. Many SNPs were excluded because there was no variability in their CNVs. Though no SNPs found significant at genome-wide level of significance (<10-5), a number of SNPs were significant at the level of individual tests in these comparisons. Four SNPs at a p value <0.0001 were identified. A SNP in the promoter region of H(+)-myo-inositol co-transporter gene was most frequently associated with pCR. Analysis of baseline serum protein data (n = 34). The results of pCR vs. serum protein data analysis suggest that there is a statistically significant difference between the concentration of bFGF and Tie-2 in the pCR group (higher baseline values) and those in the non-pCR group (p-values <0.05). The difference of concentrations of VEGF trended toward significance between these two groups. Conclusion: Elevated serum baseline Tie-2 and bFGF and special SNP in the promoter of H(+)-myo-inositol co-transporter gene are candidate predictors for pCR in response to B/CT and need to be validated in a larger clinical study. [ABSTRACT FROM AUTHOR]

Background: Age-adjusted breast cancer rates vary across and within states. However, most statistical models inherently identify either individual- or area-level determinants to explain geographic disparities in breast cancer rates and ignore the effects of the other level of determinants. We present a micro-macro modelling approach that incorporates both levels of determinants to better explain this variability and to discover opportunities to reduce breast cancer rates., Methods: Individual-level data about breast cancer risk factors from eligible Arkansas Rural Community Health (ARCH) study participants (n=13,554) was supplemented with publicly available county-level data using a novel micro-macro statistical approach. This model uses individual-level data to account for aggregation-induced biases, to predict county-level breast cancer incidence rates across Arkansas., Results: County-level breast cancer incidence rates ranged from 80.9 to 161.6 per 100,000 population. The best-fit model, which included individual-level predicted risk based on the Gail/CARE models, county-level population density (log transformed), and lead exposure (log transformed), explained 14.1% of the county variance., Conclusions: Our results support theoretical models that maintain that area-level determinants of breast cancer incidence are key risk factors in addition to established individual risks., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/tcr.2019.06.08). The series “Population Science in Cancer” was commissioned by the editorial office without any funding or sponsorship. The authors have no other conflicts of interest to declare., (2019 Translational Cancer Research. All rights reserved.)

Our pilot study examined global DNA methylation and telomere length (TL) using DNA from saliva samples provided by 39 participants in the Arkansas Rural Community Health (ARCH) Study. TL was quantified by qPCR, and DNA methylation and DNA methylation age was assessed using the Illumina 850K Epic BeadChip. Ingenuity Pathway Analysis (IPA) was performed to identify biological pathways that were DM between residents of counties with high or low poverty rates and by race [African American descent (AA) versus European American (EA) descent]. Among AA women, hypermethylation was more common in AA residents of counties with low compared to high poverty rates (70% vs. 30%). The top canonical pathways impacted by differential methylation were related to glucocorticoid receptor, p53, and estrogen-dependent breast cancer signaling in AA women. EA women living in low-poverty counties exhibited less hypermethylation of CpGs than those living in high-poverty counties (27% vs. 73%). The top canonical pathways were related to hereditary breast cancer, glucocorticoid receptor, androgen and PI3K/AKT signaling. Several genes involved in telomere maintenance were shown to be DM by county poverty levels. Therefore, the finding of this pilot study suggests county poverty levels may impact DNA methylation patterns in breast cancer-related pathways as well as genes involved in telomere maintenance. Larger studies should confirm our findings., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/tcr.2019.02.07). The authors have no conflicts of interest to declare., (2019 Translational Cancer Research. All rights reserved.)

African American women in the state of Arkansas have high breast cancer mortality rates. Breast cancer risk assessment tools developed for African American underestimate breast cancer risk. Combining African American breast cancer associated single-nucleotide polymorphisms (SNPs) into breast cancer risk algorithms may improve individualized estimates of a woman's risk of developing breast cancer and enable improved recommendation of screening and chemoprevention for women at high risk. The goal of this study was to confirm with an independent dataset consisting of Arkansas women of color, whether a genetic risk score derived from common breast cancer susceptibility SNPs can be combined with a clinical risk estimate provided by the Breast Cancer Risk Assessment Tool (BCRAT) to produce a more accurate individualized breast cancer risk estimate. A population-based cohort of African American women representative of Arkansas consisted of 319 cases and 559 controls for this study. Five-year and lifetime risks from the BCRAT were measured and combined with a risk score based on 75 independent susceptibility SNPs in African American women. We used the odds ratio (OR) per adjusted standard deviation to evaluate the improvement in risk estimates produced by combining the polygenic risk score (PRS) with 5-year and lifetime risk scores estimated using BCRAT. For 5-year risk OR per standard deviation increased from 1.84 to 2.08 with the addition of the polygenic risk score and from 1.79 to 2.07 for the lifetime risk score. Reclassification analysis indicated that 13% of cases had their 5-year risk increased above the 1.66% guideline threshold (NRI = 0.020 (95% CI -0.040, 0.080)) and 6.3% of cases had their lifetime risk increased above the 20% guideline threshold by the addition of the polygenic risk score (NRI = 0.034 (95% CI 0.000, 0.070)). Our data confirmed that discriminatory accuracy of BCRAT is improved for African American women in Arkansas with the inclusion of specific SNP breast cancer risk alleles., Competing Interests: We have the following interests: A. Starlard-Davenport and R. Henry-Tillman report receiving commercial research support from Genetic Technologies Ltd. R. Allman is Scientific Director at Genetic Technologies Ltd. and Erika Spaeth Tuff is employed by Phenogen Sciences Inc. There are no patents, products in development or marketed products to declare. This does not alter our adherence to all the PLOS ONE policies on sharing data and materials, as detailed online in the guide for authors.

Background: African-American women, especially in the southern United States, are underrepresented in cancer genetics research. A study was designed to address this issue by investigating the germline mutation rate in African-American women in Arkansas with a personal and/or family history of breast cancer. Women were tested for these mutations using a large panel of breast cancer susceptibility genes. In this analysis, we discuss the challenges encountered in recruiting African-American women from an existing biorepository to participate in this study., Methods: We attempted to contact 965 African-American women with a personal and/or family history of breast cancer who participated in Spit for the Cure (SFTC) between 2007 and 2013 and provided consent to be recontacted. The SFTC participants were invited by telephone and email to participate in the genetic study. Enrollment required completion of a phone interview to obtain a family and medical history and return of a signed consent form., Results: Among eligible SFTC participants, 39.6% (382/965) were able to be contacted with the phone numbers and email addresses they provided. Of these, 174 (45.5%) completed a phone interview and returned a signed consent form. Others were not able to be contacted ( n  = 583), declined to participate ( n  = 57), did not keep phone interview appointments ( n  = 82), completed the phone interview but never returned a signed consent ( n  = 54), were deceased ( n  = 13), or were too confused to consent to participate ( n  = 2)., Conclusions: Recruiting African-American women into our breast cancer genetics study proved challenging primarily due to difficulty establishing contact with potential participants. Given their prior participation in breast cancer research, we anticipated that this would be a highly motivated population. Indeed, when we were able to contact SFTC participants, only 14.9% declined to participate in our study. Innovative communication, retention, and recruitment strategies are needed in future studies to address the recruitment challenges we faced., Competing Interests: This study design was approved by the Institutional Review Board at the University of Arkansas for Medical Sciences.The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Pacific Islanders face many health disparities, including higher rates of cardiovascular disease, cancer, obesity, and diabetes compared to other racial and ethnic groups. Specifically, the Marshallese population suffers disproportionately from type 2 diabetes, with rates 400% higher than the general US population. As part of an ongoing community-based participatory research (CBPR) partnership, 148 participants were recruited for a study examining genetic variants to better understand diabetes. Participants provided a saliva specimen in an Oragene® DNA self-collection kit. Each participant provided approximately 2 mL volume of saliva and was asked qualitative questions about their experience. The study yielded a recruitment rate of 95.5%. Among the 148 persons who participated, 143 (96.6%) agreed to be contacted for future studies; 142 (95.9%) agreed to have their samples used for future IRB-approved studies; and 144 (97.3%) gave permission for the researchers to link information from this study to other studies in which they had participated. Qualitative responses showed that the majority of participants were willing to participate because of their desire to contribute to the health of their community and to understand the genetic influence related to diabetes. This study demonstrates willingness to participate in genetic research among Marshallese living in Arkansas. Willingness was likely enhanced because the feasibility study was part of a larger CBPR effort. This study is important to community stakeholders who have voiced a desire to collaboratively conduct genetic research related to diabetes, perinatal outcomes, and cancer.

The U.S. Preventive Services Task Force (USPSTF) recommended screening mammography every 1-2 years for women 40 years and older in 2002, and changed its recommendations in 2009 to no routine screening for women between 40 and 49 years of age; and biennial screening for women between 50 and 74 years of age. This study evaluates the change in mammographic use after the issuance of the revised recommendations. Women who participated in a cross-sectional study of breast cancer risk factors from 2007 to 2013 were asked if they had received a mammogram in the preceding 2 years. All 3442 study participants who enrolled in the study after January 1, 2011 were matched by race, age, and educational level with women enrolled between 2007 and 2010. The proportions of women who stated they had received a mammogram in the past 2 years were compared between the two groups. One fourth of the participants were African American and 39% were 40-49 years of age. Among white women, significant decreases in recent mammogram use from 2007-2010 to 2011-2013 were detected for women 40-49 years of age (-10.3%, p < 0.001) and 50-74 years of age (-8.8%, p < 0.001). Among African-American women, the change in recent mammogram use was not statistically significant for women 40-49 years of age (-2.7%, p = 0.440) or 50-74 years of age (-2.2%, p = 0.398). Following the change in the USPSTF guidelines, mammography use among white women declined; however, no change was observed among African-American women., (© 2016 Wiley Periodicals, Inc.)

Background: 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), a heterocyclic aromatic amine (HCA) formed in meat that is cooked at high temperatures and then ingested, can potentially be retained in human adipose tissues., Methods: To determine if PhIP is bioactive in the adipocyte, we exposed a human adipocyte cell line,HepG2 and Caco-2 cells to low dose PhIP. Uptake and retention of PhIP was determined and cytotoxicity was assessed by the TUNEL assay. Relative expression of PhIP-activating genes (CYP1A1, CYP1A2, SULT1A1 and UGT1A1) was determined by RT-PCR and global expression changes were also examined., Results: The percent retention of 0.1 μCi [(14)C]-PhIP over a 24 h period was significantly higher in the adipocyte than the HepG2 (p = 0.0001) and Caco-2 (p = 0.0007) cell lines. Cytotoxicity rates were 14.4 and 2.6 % higher compared to controls in Caco-2 and HepG2 cells (p < 0.001 and 0.054, respectively); no significant differences were detected in adipocyte cells (p = 0.18). Caco-2 and HepG2 cells, respectively, had significantly higher basal expression of CYP1A1 (p = 0.001, p = 0.003), SULT1A1 (p = 0.04, p < 0.001) and UGT1A1 (p < 0.001, p = 0.01) compared to the adipocyte. Exposure to 5nM PhIP did not significantly induce expression of these genes in any of the cell lines. Global gene expression analysis of mature adipocytes exposed to 5nM PhIP for 72 h resulted in statistically significant changes in 8 genes (ANGPTL2, CD14, CIDEA, EGR1, FOS, IGFBP5, PALM and PSAT1). Gene-gene interaction and pathway analysis indicates that PhIP modulates genes controlled by the STAT3 transcriptional factor and initiates leptin signaling via the JAK/STAT and MAPK pathway cascades. Early growth response 1 (EGR1) and prostaglandin synthase 2 (COX-2) were down-regulated via c-Fos, while insulin binding protein 5 (IBP5) was up regulated. Expression of transcription factors (ANGPTL2, HP, LEP, SAA1, SAA2), genes related to inflammation (SAA1, LEP), diabetes (IGFBP5) and cancer risk (SAA2) were also elevated upon exposure to 5 nM PhIP.., Conclusions: PhIP mediates gene expression changes within the adipocyte, and the pathways most affected are related to cancer and other chronic diseases. Further studies are needed on the relationship between dietary carcinogens such as PhIP with cancer, obesity and diabetes.

Introduction: Vascular endothelial growth factor (VEGF) is a central mediator of angiogenesis in breast cancer. Research in antiangiogenic cancer treatment has been marked by the development of the monoclonal antibody bevacizumab, which targets VEGF in many solid tumors. As patients do not equally benefit from bevacizumab, it has become necessary to define the profile of patients who will benefit from the drug., Materials and Methods: We have conducted a prospective phase II study in 39 patients using bevacizumab in breast cancer in the neoadjuvant setting, and found improved pathologic complete response (pCR) when bevacizumab was added to chemotherapy in patients with hormone receptor negative and invasive ductal carcinoma. Blood samples were collected at baseline and serially while patients were on treatment. Circulating angiogenesis-related proteins angiopoietin (ANG)1, ANG2, basic fibroblast growth factor, IL-1a, matrix metalloproteinase 9, platelet derived growth factor - BB, platelet endothelial cell adhesion molecule -1, Tie2, VEGF, and vascular endothelial growth factor receptor 2 were measured at baseline and during treatment. This correlative study was conducted to identify specific serum angiogenic factor profiles that might be associated with pCR in the neoadjuvant setting in breast cancer patients receiving bevacizumab and chemotherapy., Results: Elevated baseline serum Tie2 and basic fibroblast growth factor were associated with pCR in response to this combination. Changes in serum levels of these proteins were seen during treatment but were not significantly different between the pCR and non-pCR groups., Conclusions: Baseline-circulating Tie2 levels may help distinguish patients who will have pCR from those who will not and may form the basis for future development of antiangiogenic therapy in breast cancer. Larger studies are needed to validate these findings. ClinicalTrials.gov Identifier: NCT00203502.

Anastrozole is an aromatase inhibitor (AI) used as adjuvant therapy for breast cancer. Anastrozole is subject to direct glucuronidation catalyzed by UDP-glucuronosyltransferase1A4 (UGT1A4). Interindividual variability in anastrozole glucuronidation may be affected by UGT1A4 SNPs. Interplay between drug metabolizing genes such as UGT1A4 and transporter genes may also be affected by genetic variability. Thus, we hypothesize that genetic variability in MRPs could influence anastrozole glucuronidation. The correlation between UGT1A4 and MRP2 or MRP3 transporter gene expressions and the correlation between MRP2 or MRP3 mRNA and anastrozole glucuronidation were analyzed in normal human liver samples. MRP2 and MRP3 mRNA levels were significantly correlated with UGT1A4 mRNA, with anastrozole glucuronidation and with each other (p<0.05). The data also demonstrated that MRP2 SNPs are positively correlated with MRP2 mRNA expression, while there was no association between MRP3 SNPs from this study and MRP3 expression. Significant correlations (p<0.05) between certain MRP2 SNPs (3972C>T, 2366C>T and -24C>T) and anastrozole glucuronidation were observed. There were no observed correlations between MRP3 SNPs and anastrozole glucuronidation. MRP2 polymorphisms have been identified as playing a role in the disposition of other drugs, and the data presented here indicate for the first time that MRP2 SNPs could influence anastrozole metabolism and contribute to interindividual variation in treatment responses.

Published studies have identified genetic variants, somatic mutations, and changes in gene expression profiles that are associated with hepatocellular carcinoma (HCC), particularly involving genes that encode drug metabolizing enzymes (DMEs). CYP2C9, one of the most abundant and important DMEs, is involved in the metabolism of many carcinogens and drugs and is down-regulated in HCC. To investigate the molecular mechanisms that control CYP2C9 expression, we applied integrative approaches including in silico, in vitro, and in vivo analyses to elucidate the role of microRNA hsa-miR-128-3p in the regulation of CYP2C9 expression and translation. RNA electrophoresis mobility shift assays demonstrated a direct interaction between hsa-miR-128-3p and its cognate target, the CYP2C9 transcript. Furthermore, the expression of a luciferase reporter gene containing the 3'-UTR of CYP2C9 and the endogenous expression of CYP2C9 were suppressed by transfection of hsa-miR-128-3p. Importantly, chemically-induced up- or down-regulation of hsa-miR-128-3p correlated inversely with the expression of CYP2C9. Finally, an association analysis revealed that the expression of hsa-miR-128-3p is inversely correlated with the expression of CYP2C9 in HCC tumor tissues. Altogether, the study helped to elucidate the mechanism of CYP2C9 regulation by hsa-miR-128-3p, and the inverse association in HCC.

Cytosolic SULT1A1 participates in the bioconversion of a plethora of endogenous and xenobiotic substances. Genetic variation in this important enzyme such as SNPs can vary by ethnicity and have functional consequences on its activity. Most SULT1A1 genetic variability studies have been centered on the SULT1A1*1/2 SNP. Highlighted here are not only this SNP, but other genetic variants associated with SULT1A1 that could modify drug efficacy and xenobiotic metabolism. Some studies have investigated how differential metabolism of xenobiotic substances influences susceptibility to or protection from cancer in multiple sites. This review will focus primarily on the impact of SULT1A1 genetic variation on the response to anticancer therapeutic agents and subsequently how it relates to environmental and dietary exposure to both cancer-causing and cancer-preventative compounds.

Fulvestrant (Faslodex™) is a pure antiestrogen that is effective in treating estrogen receptor-(ER) positive breast cancer tumors that are resistant to selective estrogen receptor modulators such as tamoxifen. Clinical trials investigating the utility of adding fulvestrant to other therapeutics have not been shown to affect cytochrome P450-mediated metabolism. Effects on phase II metabolism and drug resistance have not been explored. This study demonstrates that fulvestrant up regulates the expression of UDP glucuronosyltransferase 1A4 (UGT1A4) >2.5- and >3.5-fold in MCF7 and HepG2 cells, respectively. Up regulation occurred in a time- and concentration-dependent manner, and was inhibited by siRNA silencing of ERα. Fulvestrant also up regulates multidrug resistance-associated proteins (MRPs). There was an up regulation of MRP2 (1.5- and 3.5-fold), and MRP3 (5.5- and 4.5-fold) in MCF7 and HepG2 cell lines, respectively, and an up regulation of MRP1 (4-fold) in MCF7 cells. UGT1A4 mRNA up regulation was significantly correlated with UGT1A4 protein expression, anastrozole glucuronidation, ERα mRNA expression and MRP mRNA expression, but not with ERα protein expression. Genetic variants in the UGT1A4 promoter (-163A, -217G and -219T) reduced the basal activity of UGT1A4 by 40-60%. In silico analysis indicated that transcription factor c-Myb binding capacity may be affected by these variations. Luciferase activity assays demonstrate that silencing c-Myb abolished UGT1A4 up regulation by fulvestrant in promoters with the common genotype (-163G, -217 T and -219C) in MCF7 cells. These data indicate that fulvestrant can influence the disposition of other UGT1A4 substrates. These findings suggest a clinically significant role for UGT1A4 and MRPs in drug efficacy.

Cytosolic sulfotransferases (SULTs) are phase II detoxification enzymes that are involved in the biotransformation of a wide variety of structurally diverse endo- and xenobiotics. Single-nucleotide polymorphisms (SNPs) in SULTs can alter the phenotype of the translated proteins. SNPs in some SULTs are fairly uncommon in the population, but some, most notably for SULT isoform 1A1, are commonly found and have been associated with cancer risk for a variety of tumor sites and also with response to therapeutic agents. SNPs in many SULTs vary by ethnicity, another factor that could influence SULT-associated disease risk and pharmacogenetics. This review surveys the current knowledge of SULT genetic variability in relation to cancer risk and response to therapy, focusing primarily on SULT1A1.

Anastrozole belongs to the nonsteroidal triazole-derivative group of aromatase inhibitors. Recently, clinical trials demonstrated improved antitumoral efficacy and a favorable toxicity with third-generation aromatase inhibitors, compared with tamoxifen. Anastrozole is predominantly metabolized by phase I oxidation with the potential for further phase II glucuronidation. It also, however, is subject to direct N-glucuronidation by UDP-glucuronosyltransferase 1A4 (UGT1A4). Anastrozole pharmacokinetics vary widely among patients, but pharmacogenomic studies of patients treated with anastrozole are sparse. In this study, we examined individual variability in the glucuronidation of anastrozole and its association with UGT1A4 promoter and coding region polymorphisms. In vitro assays using liver microsomal preparations from individual subjects (n = 96) demonstrated 235-fold variability in anastrozole glucuronidation. Anastrozole glucuronidation was correlated (r = 0.99; P < 0.0001) with lamotrigine glucuronidation (a diagnostic substrate for UGT1A4) and with UGT1A4 mRNA expression levels in human liver microsomes (r = 0.99; P < 0.0001). Recombinant UGT1A4 catalyzed anastrozole glucuronidation, which was inhibited by hecogenin (IC50 = 15 µM), a UGT1A4 specific inhibitor. The promoter region of UGT1A4 is polymorphic, and compared with those homozygous for the common allele, lower enzymatic activity was observed in microsomes from individuals heterozygous for -163G

Interleukins are a group of cytokines that contribute to growth and differentiation, cell migration, and inflammatory and anti-inflammatory responses by the immune system. In our study, we examined genetic variation in genes from various anti-inflammatory and proinflammatory interleukins to determine association with colon and rectal cancer risk and overall survival. Data from two population-based incident studies of colon cancer (1,555 cases and 1,956 controls) and rectal cancer (754 cases and 954 controls) were used. After controlling for multiple comparisons, single nucleotide polymorphisms (SNPs) from four genes, IL3, IL6R, IL8, IL15, were associated with increased colon cancer risk, and CXCR1 and CXCR2 were significantly associated with increased rectal cancer risk. Only SNPs from genes within the IL-8 pathway (IL8, CXCR1 and CXCR2) showed a significant association with both colon and rectal cancer risk. Several SNPs interacted significantly with IL8 and IFNG SNPs and with aspirin/non-steroidal anti-inflammatory drug (NSAID), cigarette smoking, estrogen use and BMI. For both colon and rectal cancer, increasing numbers of risk alleles were associated with increased hazard of death from cancer; the estimated hazard of death for colon cancer for the highest category of risk alleles was 1.74 (95% confidence interval [CI] 1.18-2.56) and 1.96 (95% CI 1.28-2.99) for rectal cancer. These data suggest that interleukin genes play a role in risk and overall survival for colon and rectal cancer., (Copyright © 2012 UICC.)

Previously, we reported five common single nucleotide polymorphisms (SNPs), -624G>C, -396G>A, -358A>C, -341C>G, and -294T>C, and six common haplotypes (CGACT, GAACT, GGAGC, GGACC, CAACT, and GAACC) in the 5'-flanking region of the SULT1A1 gene that were associated with altered enzymatic activity. In the present study, we performed in vitro assays to determine the functional impact of these genetic variations on the promoter activity. Dual luciferase reporter assays revealed that these SNPs are located in a negative regulatory fragment of the SULT1A1 gene. Further experiments demonstrated that these SNPs and haplotypes affected promoter activities of SULT1A1. Electrophoretic mobility shift assays showed distinctive binding patterns for the SNPs -396G>A and -294T>C, due to differential binding affinities of the G/A alleles and the T/C alleles to nuclear proteins extracted from the liver carcinoma cell lines, HepG2 and Huh7., (Copyright © 2012 Wiley Periodicals, Inc.)

Toremifene (TOR) is a selective estrogen receptor modulator used in adjuvant therapy for breast cancer and in clinical trials for prostate cancer prevention. The chemical structure of TOR differs from that of tamoxifen (TAM) by the presence of a chlorine atom in the ethyl side chain, resulting in a more favorable toxicity spectrum with TOR. In addition, some patients who fail on TAM therapy benefit from high-dose TOR therapy. Several studies have indicated that functional genetic variants in the TAM metabolic pathway influence response to therapy, but pharmacogenomic studies of patients treated with TOR are lacking. In this study, we examined individual variability in sulfation of 4-hydroxy TOR (4-OH TOR) (the active metabolite of TOR) in human liver cytosols from 104 subjects and found approximately 30-fold variation in activity. 4-OH TOR sulfation was significantly correlated (r = 0.98, P < 0.0001) with β-naphthol sulfation (diagnostic for SULT1A1) but not with 17β estradiol sulfation, a diagnostic substrate for SULT1E1(r = 0.09, P = 0.34). Examination of recombinant sulfotransferases (SULTs) revealed that SULT1A1 and SULT1E1 catalyzed 4-OH TOR sulfation, with apparent Km values of 2.6 and 6.4 μM and Vmax values of 8.5 and 5.5 nmol x min(-1) x mg protein(-1), respectively. 4-OH TOR sulfation was inhibited by 2,6-dichloro-4-nitrophenol (IC50 = 2.34 ± 0.19 μM), a specific inhibitor of SULT1A1. There was also a significant association between SULT1A1 genotypes and copy number and 4-OH TOR sulfation in human liver cytosols. These results indicate that variability in sulfation could contribute to response to TOR in the treatment of breast and prostate cancer.

Bone morphogenetic proteins (BMP) are part of the TGF-β-signaling pathway; genetic variation in these genes may be involved in colorectal cancer. In this study, we evaluated the association between genetic variation in BMP1 (11 tagSNPs), BMP2 (5 tagSNPs), BMP4 (3 tagSNPs), BMPR1A (9 tagSNPs), BMPR1B (21 tagSNPs), BMPR2 (11 tagSNPs) and GDF10 (7 tagSNPs) with risk of colon and rectal cancer and tumor molecular phenotype. We used data from population-based case-control studies (colon cancer n = 1,574 cases, 1,970 controls; rectal cancer n = 791 cases, 999 controls). We observed that genetic variation in BMPR1A, BMPR1B, BMPR2, BMP2 and BMP4 was associated with risk of developing colon cancer, with 20 to 30% increased risk for most high-risk genotypes. A summary of high-risk genotypes showed over a twofold increase in colon cancer risk at the upper risk category (OR = 2.49 95% CI = 1.95, 3.18). BMPR2, BMPR1B, BMP2 and GDF10 were associated with rectal cancer. BMPR2 rs2228545 was associated with an almost twofold increased risk of rectal cancer. The risk associated with the highest category of the summary score for rectal cancer was 2.97 (95% CI = 1.87, 4.72). Genes in the BMP-signaling pathway were consistently associated with CIMP+ status in combination with both KRAS-mutated and MSI tumors. BMP genes interacted statistically significantly with other genes in the TGF-β-signaling pathway, including TGFβ1, TGFβR1, Smad 3, Smad 4 and Smad 7. Our data support a role for genetic variation in BMP-related genes in the etiology of colon and rectal cancer. One possible mechanism is via the TGF-β-signaling pathway., (Copyright © 2011 UICC.)

This study sought to determine the role of copy number variants (CNV) combined with other genetic variants in the Glutathione S-transferases Mu class1 (GSTM1) promoter in the development of urinary bladder cancer. TaqMan real-time PCR and direct sequencing were used to determine genetic variants. Haploblocks and haplotype were constructed and estimated by Haploview and Phase, respectively. Logistic regression revealed a significantly decreased bladder cancer risk in subjects with at least 2 copies of GSTM1 (OR=0.56; 95%CI=0.39-0.81) but not in those with 1 copy of the gene. GSTM1 promoter screening revealed an insertion variant (-1543TTCT) and 14 single nucleotide polymorphisms (SNPs) (-1529C>G, -1490A>G, -1143A>G, -888A>T, -498G>C, -486C>G, -471C>T, -426G>A, -344C>T, -343A>T, -341C>T, -339C>T, -304G>A, and -164C>T). Four haploblocks were evident by Haploview. There was no significant association between any single SNP/haplotype and bladder cancer risk. However, when stratified by copy number, the two copy carriers with the -1543 insertion had decreased bladder cancer risk (OR, 0.58; 95%CI, 0.32-0.10) and similar results were found in two copy carriers with -888 A, -486G, - 344 C, -343 A, -341 C allele and haplotype INS(-1543)-C(-1529)-A(-1429) in LD block 1, A(-1143)-A(-888) in LD block 2, C(-498)-G(-486)-T(-471) in LD block 3, C(-344)-A(-343)-C(-341)-C(-339) and C(-344)-A(-343)-C(-341)-T(-339) in LD block 4. These results suggest that GSTM1 CNV is a better predictor of bladder cancer susceptibility than measuring presence/absence of GSTM1 and other genetic variants also can modify bladder cancer risk.

Overexpression of cyclooxygenase (COX)-2 has been implicated in the development of cancer. This study aimed to evaluate the relationship between genetic variants in COX-2 promoter interacting with Helicobacter pylori and the susceptibility to gastric cancer (GC). Three COX-2 polymorphisms -1290A>G (rs689465), -1195G>A (rs689466), and -765G>C (rs20417) were genotyped in 323 GC patients and 944 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression model. In GC patients, the ORs were 2.33 (95% CI = 1.50-3.63) and 2.70 (95% CI = 1.68-4.33) for -1195AA and -765CG genotype carriers, respectively. Haplotype analysis showed all -1195A allele-containing haplotypes, except G(-1290)-A(-1195)-G(-765), were associated with increased risk for GC, compared with the A(-1290)-G(-1195)-G(-765) haplotype. Moreover, significant multiplicative and additive interactions were observed between H. pylori infection and all these three polymorphisms, and H. pylori-infected subjects carrying the variant allele of -1290A>G, -1195G>A, or -765G>C had increased risk of GC compared with non-H. pylori-infected subjects with wild-type allele (OR = 4.10, 95% CI = 1.90-8.83; OR = 3.46, 95% CI = 1.31-9.11; and OR = 3.32, 95% = 1.27-8.73, respectively). Our results suggested that the COX-2 promoter polymorphisms were associated with increased risk of GC, especially interacting with H. pylori infection., (Copyright © 2011 Wiley Periodicals, Inc.)

CYP19A1, or aromatase, influences estrogen-metabolizing enzymes and may influence cancer risk. We examine variation in the CYP19A1 gene and risk of colorectal cancer using data from population-based case-control studies (colon n = 1,574 cases, 1,970 controls; rectal n = 791 cases, 999 controls). Four SNPs were statistically significantly associated with colon cancer and four were associated with rectal cancer. After adjustment for multiple comparisons, the AA genotype of rs12591359 was associated with an increased risk of colon cancer (OR 1.44 95% CI 1.16-1.80) and the AA genotype of rs2470144 was associated with a reduced risk of rectal cancer (OR 0.65 95% CI 0.50-0.84). Variants of CYP19A1 were associated with CIMP+ and CIMP+/KRAS2-mutated tumors. CT/TT genotypes of rs1961177 were significantly associated with an increased likelihood of a MSI+ colon tumor (OR 1.77 95% CI 1.26-2.37). We observed statistically significant interactions between genetic variation in NFκB1 and CYP19A1 for both colon and rectal cancer. Our data suggest the importance of CYP19A1 in the development of colon and rectal cancer and that estrogen may influence risk through an inflammation-related mechanism.

Breast cancer continues to be among the most common cancers affecting women in the United States. Researchers investigating the area are turning their attention to novel prevention, detection, and treatment options. Recent molecular epidemiology research has highlighted the effects of both genetic and environmental exposures on an individual's risk of developing breast cancer and predicted response to treatment. Cohort designs are a potentially powerful tool that researchers can utilize to investigate the genetic and environmental factors affecting breast cancer risk and treatment options. This paper describes the recruitment of a community-based cohort of women in a southern state. The Spit for the Cure Cohort (SFCC), being developed by researchers at the University of Arkansas for Medical Sciences (Little Rock, AR), is designed to be representative of the female population of the state with oversampling of women with a history of breast cancer and women of color. To date, the SFCC includes more than 14,000 women recruited from all 75 counties of Arkansas and six neighboring states. Methods used to recruit and maintain the cohort and collect both questionnaire data and genetic material are described, as are the demographic characteristics of the cohort as it currently exists. The recruitment methods utilized for the SFCC are rapidly building a breast cancer cohort and providing a large biorepository for molecular epidemiology research., (© 2011 Wiley Periodicals, Inc.)

Recent studies have linked expression of lectin-like ox-LDL receptor 1 (OLR1) to tumorigenesis. We analyzed microarray data from Olr1 knockout (KO) and wild type (WT) mice for genes involved in cellular transformation and evaluated effects of OLR1 over-expression in normal mammary epithelial cells (MCF10A) and breast cancer cells (HCC1143) in terms of gene expression, migration, adhesion and transendothelial migration. Twenty-six out of 238 genes were inhibited in tissues of OLR1 KO mice; the vast majority of OLR1 sensitive genes contained NF-κB binding sites in their promoters. Further studies revealed broad inhibition of NF-kB target genes outside of the transformation-associated gene pool, with enrichment themes of defense response, immune response, apoptosis, proliferation, and wound healing. Transcriptome of Olr1 KO mice also revealed inhibition of de novo lipogenesis, rate-limiting enzymes fatty acid synthase (Fasn), stearoyl-CoA desaturase (Scd1) and ELOVL family member 6 (Elovl6), as well as lipolytic phospholipase A2 group IVB (Pla2g4b). In studies comparing MCF10A and HCC1143, the latter displayed 60% higher OLR1 expression. Forced over-expression of OLR1 resulted in upregulation of NF-κB (p65) and its target pro-oncogenes involved in inhibition of apoptosis (BCL2, BCL2A1, TNFAIP3) and regulation of cell cycle (CCND2) in both cell lines. Basal expression of FASN, SCD1 and PLA2G4B, as well as lipogenesis transcription factors PPARA, SREBF2 and CREM, was higher in HCC1143 cells. Over-expression of OLR1 in HCC1143 cells also enhanced cell migration, without affecting their adherence to TNFα-activated endothelium or transendothelial migration. On the other hand, OLR1 neutralizing antibody inhibited both adhesion and transmigration of untreated HCC1143 cells. We conclude that OLR1 may act as an oncogene by activation of NF-kB target genes responsible for proliferation, migration and inhibition of apoptosis and de novo lipogenesis genes.

Sulfotransferase isoform 1A1 (SULT1A1) is the most highly expressed hepatic sulfotransferase and is involved in the biotransformation of a wide variety of endo- and xenobiotics. A common single nucleotide polymorphism (SNP) in the coding region of SULT1A1, several proximal promoter SNPs, and copy number variation (CNV) are associated with altered enzymatic activity, but these variants do not fully account for the observed variation of SULT1A1 activity in human populations. In order to identify additional SNPs modulating SULT1A1 activity, we examined the 3'-untranslated region (UTR) of SULT1A1 in 97 liver samples. Direct sequencing revealed that two SNPs in the 3'-UTR (902A > G [rs6839] and 973C > T [rs1042157]) and one SNP in the 3'-flanking region (1307G > A [rs4788068]) were common. These SNPs are in absolute linkage disequilibrium with each other and in tight linkage with SULT1A1 1/2 (linkage coefficient D' 0.83) and are significantly associated with SULT1A1 messenger RNA (p = 0.001, 0.029, 0.021) and enzymatic activity (p = 0.022, 0.012, 0.027). We then examined the collective effects of 3'-UTR SNPs, SULT1A1 1/2, and CNV on SULT1A1 activity in 498 Caucasian and 127 African-American subjects by haplotype analysis. This analysis revealed that SULT1A1 1/2 does not contribute to the variation in SULT1A1 enzymatic activity when the 3'-UTR SNPs are included in the statistical model. Two major haplotypes (ACG and GTA) were significantly correlated with SULT1A1 activity, and when stratified by copy number, the SULT1A1 3'-UTR SNPs remain significantly associated with SULT1A1 enzymatic activity in Caucasians, but not in African-Americans. Subsequent functional characterization revealed that a microRNA, miR-631, regulates SULT1A1 expression in a genotype-specific manner.

Objective: Cytochrome P450 2A6 (CYP2A6) is an important metabolic enzyme capable of activating several procarcinogens, including dietary and tobacco-specific nitrosamines, which have been linked to pancreatic cancer. Positive associations between high CYP2A6 activity and lung and colorectal cancers have been reported. This is the first investigation of CYP2A6 activity and pancreatic cancer., Design: In this case-control study of cancer of the exocrine pancreas, phenotypic CYP2A6 activity was measured using a ratio of urinary caffeine metabolites. Demographic, smoking, dietary and medical information were obtained by questionnaire. CYP2A6 phenotype, which is not influenced by smoking status, was measured for 90 cases and 470 controls., Results: When modeled as a continuous variable, and adjusted for age, sex, race, education, current smoking status and chronic pancreatitis, the odds ratio (OR) per one unit of the natural log of the CYP2A6 ratio was 1.52 (95% confidence interval, CI: 1.09-2.12). In an adjusted categorical analysis, subjects in the uppermost quartile (based on controls) of CYP2A6 activity, when compared to the lower three quartiles, carried an 80% greater risk of pancreatic cancer (OR=1.80; 95% CI: 1.07-3.02)., Conclusions: High levels of CYP2A6 activity, as measured by a caffeine phenotyping assay, were positively associated with pancreatic cancer in this casecontrol study among a Midwestern U.S. population.

Epidemiologic evidence indicates that exposure to heterocyclic amines in the diet is an important risk factor for the development of colon cancer. Well-done cooked meats contain significant levels of heterocyclic amines, which have been shown to cause cancer in laboratory animals. To better understand the mechanisms of heterocyclic amine bioactivation in humans, the most mass abundant heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was used to assess the relationship between PhIP metabolism and DNA adduct formation. Ten human volunteers where administered a dietary relevant dose of [(14)C]PhIP 48 to 72 hours before surgery to remove colon tumors. Urine was collected for 24 hours after dosing for metabolite analysis, and DNA was extracted from colon tissue and analyzed by accelerator mass spectrometry for DNA adducts. All 10 subjects were phenotyped for cytochrome P4501A2 (CYP1A2), N-acetyltransferase 2, and sulfotransferase 1A1 enzyme activity. Twelve PhIP metabolites were detected in the urine samples. The most abundant metabolite in all volunteers was N-hydroxy-PhIP-N(2)-glucuronide. Metabolite levels varied significantly between the volunteers. Interindividual differences in colon DNA adducts levels were observed between each individual. The data showed that individuals with a rapid CYP1A2 phenotype and high levels of urinary N-hydroxy-PhIP-N(2)-glucuronide had the lowest level of colon PhIP-DNA adducts. This suggests that glucuronidation plays a significant role in detoxifying N-hydroxy-PhIP. The levels of urinary N-hydroxy-PhIP-N(2)-glucuronide were negatively correlated to colon DNA adduct levels. Although it is difficult to make definite conclusions from a small data set, the results from this pilot study have encouraged further investigations using a much larger study group.