Phytoestrogen consumption from foods and supplements and epithelial ovarian cancer risk: a population-based case control study
ABSTRACT While there is extensive literature evaluating the impact of phytoestrogen consumption on breast cancer risk, its role on ovarian cancer has received little attention.
We conducted a population-based case-control study to evaluate phytoestrogen intake from foods and supplements and epithelial ovarian cancer risk. Cases were identified in six counties in New Jersey through the New Jersey State Cancer Registry. Controls were identified by random digit dialing, CMS (Centers for Medicare and Medicaid Service) lists, and area sampling. A total of 205 cases and 390 controls were included in analyses. Unconditional logistic regression analyses were conducted to examine associations with total phytoestrogens, as well as isoflavones (daidzein, genistein, formononetin, and glycitein), lignans (matairesinol, lariciresinol, pinoresinol, secoisolariciresinol), and coumestrol.
No statistically significant associations were found with any of the phytoestrogens under evaluation. However, there was a suggestion of an inverse association with total phytoestrogen consumption (from foods and supplements), with an odds ratio (OR) of 0.62 (95% CI: 0.38-1.00; p for trend: 0.04) for the highest vs. lowest tertile of consumption, after adjusting for reproductive covariates, age, race, education, BMI, and total energy. Further adjustment for smoking and physical activity attenuated risk estimates (OR: 0.66; 95% CI: 0.41-1.08). There was little evidence of an inverse association for isoflavones, lignans, or coumestrol.
This study provided some suggestion that phytoestrogen consumption may decrease ovarian cancer risk, although results did not reach statistical significance.
American Journal of Clinical Nutrition 11/2014; 100(5):1217-9. DOI:10.3945/ajcn.114.098285 · 6.92 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Soy attracts attention for its health benefits, such as lowering cholesterol or preventing breast and colon cancer. Soybeans contain isoflavones, which act as phytoestrogens. Even though isoflavones have beneficial health effects, a role for isoflavones in the initiation and progression of diseases including cancer is becoming increasingly recognized. While data from rodent studies suggest that neonatal exposure to genistein (the predominant isoflavone in soy) disrupts normal reproductive function, its role in ovarian cancers, particularly granulosa cell tumors (GCT) is largely unknown. Our study aimed to define the contribution of a soy diet in GCT development using a genetically modified mouse model for juvenile GCTs (JGCT) (Smad1 Smad5 conditional double knockout) as well as a human JGCT cell line (COV434). While dietary soy cannot initiate JGCT development in mice, we show that it has dramatic effects on GCT growth and tumor progression compared to a soy-free diet. By repressing caspase-dependent apoptosis through a transcriptional mechanism, genistein can promote granulosa cell tumor growth in vitro. Loss of Smad1 and Smad5 alters estrogen receptor alpha (Esr1) expression in granulosa cells, perhaps sensitizing the cells to the effects of genistein. In addition, we found that genistein modulates estrogen receptor expression in the human JGCT cell line and positively promotes cell growth in part by suppressing caspase-dependent apoptosis. Combined, our work suggests that dietary soy consumption has deleterious effects on GCT development.Biology of Reproduction 08/2014; DOI:10.1095/biolreprod.114.120899 · 3.45 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Daidzein is a major component of isoflavones, and its hydroxylated forms are valuable phytochemicals with anti-cancer and anti-oxidant activity. Due to the limitations of chemical synthesis of these hydroxylated structures, alternative enzymatic synthesis has been attempted. Previously, several protein-engineering approaches using CYP102D1 were investigated; these produced mutants with daidzein hydroxylation activity and regioselectivity through rational design (F96V/M246I) and saturation mutagenesis (A273H/G274E/T277G). However, the generated mutants have low regioselectivity (F96V/M246I) or low hydroxylation activity (A273H/G274E/T277G). Here, we characterized mutants capable of catalyzing C3'-specific daidzein hydroxylation with enhanced hydroxylation activity and regioselectivity. In order to obtain regioselectivity toward the daidzein C3'-position, site-saturation mutagenesis on the substrate-binding region of CYP102D1 F96V/M246I was investigated. A high-throughput screening assay was then performed, based on O-dealkylation activity against the daidzein analog substrate 4'-O-methyl-daidzein. This resulted in a mutant with more than 23-fold improved hydroxylation activity (55.6±17.9μM(-1)min(-1), or 48.4mg/L titer) and regioselectivity over the 3'/6-position that was increased by three-fold (from 0.9 to 2.6) compared with the F96V/M246I template enzyme. Furthermore, we carried out docking simulation studies that could partially explain the effects of these mutations on C3'-specific hydroxylation activity. Copyright © 2015 Elsevier Inc. All rights reserved.Enzyme and Microbial Technology 01/2015; 71. DOI:10.1016/j.enzmictec.2015.01.004 · 2.97 Impact Factor