Risk of female breast cancer and serum concentrations of organochlorine pesticides and polychlorinated biphenyls: a case-control study in Tunisia.

The aim of this study was to investigate the association between serum concentrations of a group of organochlorine pesticides/polychlorinated biphenyls with xenoestrogenic potential and the risk of breast cancer in a female population from Tunisia. The relationship between serum levels of the pollutants and the risk of cancer was assessed using logistic regression analyses. In the unadjusted models, ß-hexachlorocyclohexane (ß-HCH), hexachlorobenzene, heptachlor, polychlorinated biphenyl congeners 138, 153, and 180, and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) were positively associated with breast cancer risk. However, when the models were further adjusted for the selected covariates, only ß-HCH and p,p'-DDE remained statistically significant, and heptachlor was borderline significant. In addition, analyses using POP concentration tertiles corroborated a positive dose-response relationship that was significant for p,p'-DDE (p-trend=0.020) and borderline significant for heptachlor (p-trend=0.078). A similar trend was also confirmed for ß-HCH, in which concentrations≥limit of detection were positively associated with breast cancer risk (vs. concentrations

Assessment of estrogenic and anti-androgenic activities of the mycotoxin zearalenone and its metabolites using in vitro receptor-specific bioassays.

Zearalenone (ZEN) is a well-known mycotoxin present in numerous agricultural products. Humans and animals are therefore at a risk of exposure to zearalenone through consumption of contaminated food. After intake, ZEN is reduced to α- and ß-zearalenol (α-ZEL and ß-ZEL), zearalanone (ZAN), and α- and ß-zearalanol (α-ZAL and ß-ZAL). Although their estrogenicity has been well characterized, much less is known about their interaction with other nuclear receptors. This study was undertaken to investigate interactions of ZEN and its five metabolites, with the human androgen receptor (hAR) and estrogen receptor alpha (hERα). Their ability to induce hAR-mediated reporter gene expression was examined in androgen-sensitive PALM cells, whereas the effects on hERα function were assessed in MCF-7 cells using the E-Screen bioassay. We confirm that ZEN and its metabolites are full agonists for hERα and demonstrate that all six compounds tested possess hAR-mediated antagonistic activity in PALM cells, in which ZAN, α-ZAL, and ß-ZAL were the most effective hAR antagonists. Overall, the observed estrogenic and anti-androgenic potencies of ZEN and its metabolites suggest that these compounds may interfere with the endocrine system by various modes of action and that further investigation is warranted into their role as endocrine disrupters in animals and humans.