Xenoestrogens modulate genotoxic (UVB)-induced cellular responses in estrogen receptors positive human breast cancer cells

Human populations and wildlife are exposed to mixtures of both anthropogenic and natural chemicals. Some of these compounds are known to interact principally with the endocrine function, whereas others act mainly on genomic DNA. Given this evidence, we wanted to address the question of whether concomitant exposure of such chemicals was able to interact at the cellular level. We have previously shown that 17β-Estradiol (E2) modulates the DNA repair capacity of cells. In this work, we wanted to examine if other xenoestrogens (i.e. industrial compounds, pesticides or pharmaceuticals) were able to interact with the UVB-induced cellular response as E2 does. Here, we show that xenoestrogens modulate the capacity of cells to repair their DNA damage according to the type of compounds. For example, the oral contraceptive 17α-Ethinylestradiol down-regulated the repair of UVB-induced DNA damage whereas the UV filter Eusolex 6007 up-regulated this pathway. The notion that xenoestrogens could interact with a genotoxic stress is reinforced by the modulation of the estrogens-dependent luciferase reporter gene expression when cells are UVB-irradiated. Finally, these observations suggested the potential role of xenoestrogens in carcinogenesis by their capacity to modulate cells responses to genotoxic stress.