Low­Level Environmental Heavy Metals are Associated with Obesity Among Postmenopausal Women in a Southern State.

Both arsenic and cadmium are reported to be toxic to humans. The use of saliva as a biomarker of low-level exposures to these elements has not been adequately explored, and the putative relationship between exposure and obesity is unclear. This cross-sectional study aims to investigate the relationship between salivary arsenic and cadmium concentrations and their association with obesity. Arsenic and cadmium concentrations were analyzed in human saliva samples by Inductively Coupled Plasma-Mass Spectrometry on 270 randomly selected women who participated in the Arkansas Rural Community Health Study. Multivariable logistic regression was performed to evaluate the association between heavy metal concentrations and obesity. Stratified logistic regression was performed based on menopausal status. Generalized linear models were used to evaluate weight gain velocity. Significant positive associations were observed in postmenopausal women for both arsenic (OR = 4.43, 95% CI 1.91-10.28) and cadmium (OR = 2.72, 95% CI 1.23-5.99) concentrations, as well as significant trends among tertiles (p < 0.01 and p = 0.01, respectively). No relationship with obesity was evident among premenopausal women for either metal. A dose-response relationship was observed between increasing weight gain velocity and increasing metal concentrations. At concentrations well below governmental and industrial standards for acute toxicity, significant associations between obesity and concentration of these heavy metals are evident. The rate at which individuals gain weight is affected by metal concentrations and may play a role in the rapid increase in weight in postmenopausal women. These results might explain, in part, the missing variability in the increasing obesity pandemic in certain population exposed to these environmental toxicants.

Association of DNA-Methylation Profiles With Immune Responses Elicited in Breast Cancer Patients Immunized With a Carbohydrate-Mimicking Peptide: A Pilot Study.

Immune response to a given antigen, particularly in cancer patients, is complex and is controlled by various genetic and environmental factors. Identifying biomarkers that can predict robust response to immunization is an urgent need in clinical cancer vaccine development. Given the involvement of DNA methylation in the development of lymphocytes, tumorigenicity and tumor progression, we aimed to analyze pre-vaccination DNA methylation profiles of peripheral blood mononuclear cells (PBMCs) from breast cancer subjects vaccinated with a novel peptide-based vaccine referred to as P10s-PADRE. This pilot study was performed to evaluate whether signatures of differentially methylated (DM) loci can be developed as potential predictive biomarkers for prescreening subjects with cancer who will most likely generate an immune response to the vaccine. Genomic DNA was isolated from PBMCs of eight vaccinated subjects, and their DNA methylation profiles were determined using Infinium® MethylationEPIC BeadChip array from Illumina. A linear regression model was applied to identify loci that were differentially methylated with respect to anti-peptide antibody titers and with IFN-γ production. The data were summarized using unsupervised-learning methods: hierarchical clustering and principal-component analysis. Pathways and networks involved were predicted by Ingenuity Pathway Analysis. We observed that the profile of DM loci separated subjects in regards to the levels of immune responses. Canonical pathways and networks related to metabolic and immunological functions were found to be involved. The data suggest that it is feasible to correlate methylation signatures in pre-treatment PBMCs with immune responses post-treatment in cancer patients going through standard-of-care chemotherapy. Larger and prospective studies that focus on DM loci in PBMCs is warranted to develop pre-screening biomarkers before BC vaccination. Clinical Trial Registration: www.ClinicalTrials.gov, Identifier: NCT02229084.

Genome-wide DNA methylation signatures to predict pathologic complete response from combined neoadjuvant chemotherapy with bevacizumab in breast cancer.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00203502.

Mobile Mammography Screening as an Opportunity to Increase Access of Rural Women to Breast Cancer Research Studies.

OBJECTIVES: Rural women are underrepresented in cancer research. We hypothesized that providing access to a research study to rural, medically underserved women who were receiving their breast cancer screening using a mobile mammography unit would increase the representation of rural women in a cancer cohort study. DESIGN: This study is a cross-sectional study using a cohort of women who have been recruited to a breast cancer study in Arkansas. SETTING: Recruiters accompanied a mobile mammography unit, the MammoVan, to implement a novel method for reaching and recruiting underrepresented rural Arkansas women into the study. Participants include 5850 women recruited from 2010 through 2012 as part of the Arkansas Rural Community Health (ARCH) study. RESULTS: Participants recruited during their mammography screening on the MammoVan tended to be more rural, less educated, and more likely to be non-Hispanic than those recruited in other venues. A significant difference was not noted for race or age. CONCLUSION: Collaboration with the MammoVan greatly aided the recruitment of rural participants. These strategies can facilitate the representation of this historically underserved and understudied rural population in future research studies.

Development and Evaluation of a Blood Glucose Monitoring YouTube Video for Marshallese Patients Using a Community-Based Participatory Research Approach.

The purpose of this study was to (a) describe the development of a culturally appropriate glucose monitoring video using a community-based participatory research approach and (b) assess the cultural appropriateness and effectiveness of the video. The topic of the video-using a glucometer and the importance of performing blood glucose checks-was chosen by Marshallese community stakeholders. The video was produced in Marshallese with English subtitles and disseminated through YouTube. Participants were recruited from August 16, 2016 to September 12, 2016 in a diabetes clinic that serves Marshallese patients in northwest Arkansas. Fifty participants completed a survey at pre- and postintervention, with questions capturing demographic information and questions on glucose monitoring self-efficacy using an adapted version of the Stanford Patient Education Research Center's Diabetes Self-Efficacy Scale. Twenty of those participants who completed the survey also completed semistructured interviews that assessed cultural appropriateness and effectiveness of the video. Participants reported significant increases in self-efficacy related to glucometer use and the importance of performing blood glucose checks (p < .001) and a 1.45% reduction in A1C between preintervention and 12 weeks postintervention (p = .006). Qualitative results indicated the video was both culturally appropriate and effective. The findings of this study were consistent with evidence in the literature, which shows health education videos can be effective at improving health behaviors. Using a community-based participatory research approach to prioritize video topics, and including members of the community in the creation and dissemination of the videos, could aid in ensuring the videos are effective and culturally appropriate.

Germline Genetic Variants in GATA3 and Breast Cancer Treatment Outcomes in SWOG S8897 Trial and the Pathways Study.

INTRODUCTION: GATA3 is a critical transcription factor in maintaining the differentiated state of luminal mammary epithelial cells. We sought to determine the prognostic and predictive roles of GATA3 genotypes for breast cancer. PATIENTS AND METHODS: Twelve single nucleotide polymorphisms (SNPs) were genotyped in 2 breast cancer cohorts, including the SWOG S8897 trial where patients were treated with adjuvant chemotherapy (CAF [cyclophosphamide, doxorubicin, 5-fluorouracil] vs. CMF [cyclophosphamide, methotrexate, 5-fluorouracil]) or untreated, and the observational Pathways Study. RESULTS: In the S8897 trial, rs3802604 and rs568727 were associated with disease-free survival and overall survival in the treated group, regardless of chemotherapy regimen. The GG genotype of rs3802604 conferred poorer overall survival (adjusted hazard ratio, 2.45; 95% confidence interval, 1.48-4.05) and disease-free survival (adjusted hazard ratio, 1.95; 95% confidence interval, 1.27-2.99) compared with the AA genotype. Similar associations were found for rs568727. In contrast, no association with either SNP was found in the untreated group. Subgroup analyses indicated that these 2 SNPs more strongly influenced outcomes in the patients who also received tamoxifen. However, the associations in the subgroup with tamoxifen treatment were not replicated in the Pathways Study, possibly owing to substantial differences between the 2 patient cohorts, such as chemotherapy regimen and length of follow-up. Results from joint analyses across these 2 cohorts were marginally significant, driven by the results in S8897. Bioinformatic analyses support potential functional disruption of the GATA3 SNPs in breast tissue. CONCLUSIONS: The present study provides some evidence for the predictive value of GATA3 genotypes for breast cancer adjuvant therapies. Future replication studies in appropriate patient populations are warranted.

County poverty levels influence genome-wide DNA methylation profiles in African American and European American women.

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.

Individual- and county-level determinants of high breast cancer incidence rates.

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.

Association between breast cancer risk and leisure physical activity in a rural cohort population.

BACKGROUND: Physical activity has been identified as a modifiable risk factor for breast cancer. Varying definitions of physical activity have made the evaluation difficult to analyze. In a state with high prevalence of obesity and elevated rates of breast cancer incidence and mortality, physical activity may be an important element for risk reduction. Women's participation in physical activity and the relation to breast cancer incidence has rarely been determined in the southern states where obesity are prevalent. METHODS: Associations between various levels of physical activity and incident breast cancer cases among 21,665 subjects residing in Arkansas from 2007-2018 were completed. Multivariate logistic regression was used to estimate the odds ratios (OR) and 95% confidence intervals (95% CI), adjusting for various risk factors such as age, alcohol use, education, region, ethnicity, age at menarche, ever had children, and history of breastfeeding and family history of breast cancer. Stratification on menopausal status was performed to observe any breast cancer differences within the different biological pathways. RESULTS: Among premenopausal subjects, inverse associations were observed among increase time in walking (OR =0.63, 95% CI: 0.36-1.11 and OR =0.47, 95% CI: 0.26-0.83) and overall weekly physical activity (OR =0.89, 95% CI: 0.50-1.57 and OR =0.52, 95% CI: 0.30-0.90) and breast cancer. No association was evident between the risk for breast cancer and physical activity among postmenopausal subjects. The relationship between physical activity and risk for breast cancer differed between menopausal statuses. The most apparent association was seen among premenopausal subjects with an increase in walking (P=0.01). CONCLUSIONS: Although physical activity has been demonstrated to have a beneficial effect on breast cancer prevention among postmenopausal women, results from this study do not sufficiently support the hypothesis in this population. Results varied among menopausal status as well as among different definitions of physical activity. Further investigation is needed to identify factors contributing to de-attenuating the relationships.

Validation of a genetic risk score for Arkansas women of color.

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.

Challenges in recruiting African-American women for a breast cancer genetics study.

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.

A functional SNP in the 3'-UTR of TAP2 gene interacts with microRNA hsa-miR-1270 to suppress the gene expression.

The transporter associated with antigen processing 2 (TAP2) is involved in the development of multidrug resistance and the etiology of immunological diseases. In this study, we investigated whether the expression of TAP2 can be perturbed by single nucleotide polymorphisms (SNPs) located in 3'-untranslated region (3'-UTR) of the gene via interactions with microRNAs. Using a series of in silico assays, we selected the candidate microRNAs (miRNAs) with the potential to interact with functional SNPs of TAP2. The SNP rs241456-located in the 3'-UTR of TAP2-resides in a potential binding site for hsa-miR-1270 and hsa-miR-620. HEK 293 cells, from a human kidney cell line, were used to characterize the extent of binding of miRNAs to each polymorphic allele of the SNP by a luciferase reporter gene assay. RNA electrophoretic mobility shift assays were used to evaluate the interaction between the miRNAs and each allele sequence of the SNP. We found that hsa-miR-1270 inhibited luciferase activity by binding to the T allele of the SNP in an allele-specific manner. A negative correlation was also found between the expression of hsa-miR-1270 and the T allele of the SNP in kidney tissues. Our findings support the hypothesis that hsa-miR-1270 suppresses the production of TAP2 by binding to this SNP in the 3'-UTR of this gene. Environ. Mol. Mutagen. 59:134-143, 2018. © 2017 Wiley Periodicals, Inc.

A high frequency missense SULT1B1 allelic variant (L145V) selectively expressed in African descendants exhibits altered kinetic properties.

1. Human cytosolic sulfotransferase 1B1 (SULT1B1) sulfates small phenolic compounds and bioactivates polycyclic aromatic hydrocarbons. To date, no SULT1B1 allelic variants have been well-characterized. 2. While cloning SULT1B1 from human endometrial specimens, an allelic variant resulting in valine instead of leucine at the 145th amino acid position (L145V) was detected. NCBI reported this alteration as the highest frequency SULT1B1 allelic variant. 3. L145V frequency comprised 9% of 37 mixed-population human patients and was specific to African Americans with an allelic frequency of 25%. Structurally, replacement of leucine with valine potentially destabilizes a conserved helix (α8) that forms the "floor" of both the substrate and PAPS binding domains. This destabilization results in altered kinetic properties including a four-fold decrease in affinity for PAP (3', 5'-diphosphoadenosine). Kms for 3'-phosphoadenosine- 5'-phosphosulfate (PAPS) are similar; however, maximal turnover rate of the variant isoform (0.86 pmol/(min*µg)) is slower than wild-type (WT) SULT1B1 (1.26 pmol/(min*µg)). The L145V variant also displays altered kinetics toward small phenolic substrates, including a diminished p-nitrophenol Km and increased susceptibility to 1-naphthol substrate inhibition. 4. No significant correlation between genotype and prostate or colorectal cancer was observed in patients; however, the variant isoform could underlie specific pathologies in sub-Saharan African carriers.

Leveraging community-based participatory research capacity to recruit Pacific Islanders into a genetics study.

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.

Germline Genetic Variants in TEK, ANGPT1, ANGPT2, MMP9, FGF2 and VEGFA Are Associated with Pathologic Complete Response to Bevacizumab in Breast Cancer Patients.

BACKGROUND: We previously reported improved pathologic complete response (pCR) in a prospective phase II study using neoadjuvant bevacizumab in combination with chemotherapy compared to chemotherapy alone in breast cancer patients (41% vs. 25%, p = 0.0291). In this study, we queried germline single-nucleotide polymorphisms (SNPs) in angiogenesis-related genes for their impact on pCR and overall survival (OS). METHODS: DNA for genotyping was available from 34 subjects who received bevacizumab in addition to chemotherapy and 29 subjects who did not. Using Illumina® technology, we queried 504 SNPs with a minor allele frequency (MAF) of at least 5%, located in 10 angiogenesis-related genes, for their effect on pCR via logistic regression with an additive-inheritance model while adjusting for race and bevacizumab treatment. SNPs that showed significant associations with pCR were selected for additional characterization. RESULTS: After adjusting for race and tumor type, patients who had bevacizumab added to their neoadjuvant therapy were found to experience a significantly improved rate of pCR compared to patients who did not (adjusted OR 8.40, 95% CI 1.90-37.1). When patients were analyzed for SNP effects via logistic regression with race and bevacizumab treatment included as covariates, two SNPs in angiopoietin 1 (ANGPT1), six in ANGPT2, three in fibroblast growth factor 2 (FGF2), four in matrix metalloproteinase 9 (MMP9), three in tyrosine kinase, endothelial (TEK) and two in vascular endothelial growth factor A (VEGFA) were associated with pCR (P<0.05). However, when overall survival was considered, there was no difference between treatment groups or between genotypes. CONCLUSION: Genetic variability in TEK, ANGPT1, ANGPT2, FGF2, MMP9 and VEGFA is associated with pCR in bevacizumab-treated patients. Consistent with other studies, adding bevacizumab to standard chemotherapy did not impact OS, likely due to other factors and thus, while SNPs in TEK, ANGPT1, ANGPT2, FGF2, MMP9 and VEGFA were associated with pCR, they were not predictive of OS in this patient population. TRIAL REGISTRATION: ClinicalTrials.gov NCT00203502.

Change in Mammography Use Following the Revised Guidelines from the U.S. Preventive Services Task Force.

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.

2-amino-1-methyl-6-phenylimidazo(4,5-b) pyridine (PhIP) induces gene expression changes in JAK/STAT and MAPK pathways related to inflammation, diabetes and cancer.

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.

High-circulating Tie2 Is Associated With Pathologic Complete Response to Chemotherapy and Antiangiogenic Therapy in Breast Cancer.

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.

Modulation of ALDH5A1 and SLC22A7 by microRNA hsa-miR-29a-3p in human liver cells.

Observed variations in drug responses among patients may result from differences in heritable genetic traits or from alterations in the epigenetic regulation of drug metabolizing enzymes and transporters (DMETs). MicroRNAs (miRNAs), a group of small non-coding RNAs, provide an epigenetic mechanism for fine-tuning the expression of targeted DMET genes by regulating the efficiency of protein translation and by decreasing mRNA stability via enhanced degradation. In the current study we systematically screened 374 important genes encoding DMETs for potential response elements to hsa-miR-29a-3p, a highly abundant miRNA in human liver. RNA electrophoresis mobility shift assays displayed direct interactions between hsa-miR-29a-3p and its cognate targets within the mRNA transcripts for the ABCC6, SLC22A7 and ALDH5A1 genes. The expression of luciferase reporter genes containing the 3'-UTRs of SLC22A7 or ALDH5A1 and the expression of endogenous SLC22A7 and ALDH5A1 were each suppressed by transfection with hsa-miR-29a-3p mimics. Importantly, chemically-induced up-regulation of hsa-miR-29a-3p correlated inversely with the expression of SLC22A7 and ALDH5A1. However, our studies failed to detect suppressive effects of hsa-miR-29a-3p on ABCC6 expression, which might be explained by the notion that the interaction of hsa-miR-29a-3p and ABCC6 mRNA was unable to recruit ribonucleoproteins to form a RNA-induced silencing complex.

Human UDP-Glucuronosyltransferases: Effects of altered expression in breast and pancreatic cancer cell lines.

Increased aerobic glycolysis and de novo lipid biosynthesis are common characteristics of invasive cancers. UDP-glucuronosyltransferases (UGTs) are phase II drug metabolizing enzymes that in normal cells possess the ability to glucuronidate these lipids and speed their excretion; however, de-regulation of these enzymes in cancer cells can lead to an accumulation of bioactive lipids, which further fuels cancer progression. We hypothesize that UGT2B isoform expression is down-regulated in cancer cells and that exogenous re-introduction of these enzymes will reduce lipid content, change the cellular phenotype, and inhibit cancer cell proliferation. In this study, steady-state mRNA levels of UGT isoforms from the 2B family were measured using qPCR in 4 breast cancer and 5 pancreatic cancer cell lines. Expression plasmids for UGT2B isoforms known to glucuronidate cellular lipids, UGT2B4, 2B7, and 2B15 were transfected into MCF-7 and Panc-1 cells, and the cytotoxic effects of these enzymes were analyzed using trypan blue exclusion, annexin V/PI staining, TUNEL assays, and caspase-3 immunohistochemistry. There was a significant decrease in cell proliferation and a significant increase in the number of dead cells after transfection with each of the 3 UGT isoforms in both cell lines. Cellular lipids were also found to be significantly decreased after transfection. The results presented here support our hypothesis and emphasize the important role UGTs can play in cellular proliferation and lipid homeostasis. Evaluating the effect of UGT expression on the lipid levels in cancer cell lines can be relevant to understanding the complex regulation of cancer cells, identifying the roles of UGTs as "lipid-controllers" in cellular homeostasis, and illustrating their suitability as targets for future clinical therapy development.