Bisphenol A-Induced Cell Proliferation and Mitochondrial Oxidative Stress Are Diminished via Modulation of TRPV1 Channel in Estrogen Positive Breast Cancer Cell by Selenium Treatment.

Cancer cell proliferation and apoptosis are induced by overload Ca²⁺ entry. Transient receptor potential vanilloid 1 (TRPV1) as a Ca²⁺ permeable cation channel is activated by capsaicin and reactive oxygen species (ROS), although it is blocked by capsazepine and sodium selenite (Na-Se). Bisphenol A (BPA) induces estrogenic action and further stimulates the proliferation of estrogen receptor positive MCF-7 cell through excessive production ROS and Ca²⁺ influx. However, whether or not Na-Se can influence BPA-induced oxidative stress and apoptosis through modulation of TRPV1 in breast cancer cells has not drawn much attention. The MCF-7 and MDA-MB-231 breast cancer cells were divided into four treatment groups as control, Na-Se (1 μM for 2 h), and BPA (0.1 mM for 24 h) and BPA + Na-Se. The Na-Se reduced BPA-induced increase of cell number, mitochondria oxidative stress, and TRPV1 channel activity modulation of MCF-7 cells, which was proved by the suppression of cell viability, excessive ROS production, mitochondrial membrane depolarization, lipid peroxidation, early apoptosis (Annexin-V), late apoptosis (propidium iodide) and upregulation of reduced glutathione, glutathione peroxidase, and cell death (propidium iodide/Hoechst rate). The similar effects of Na-Se were observed in the MCF-7 cells by capsazepine treatment. However, the effects of BPA were not observed in the MDA-MB-231 breast cancer cells. In conclusion, cell proliferative and oxidant effects of BPA were increased by activation of TRPV1, but its action on the values was decreased by the Na-Se treatment. The results may be a good set of preliminary data for designing animal studies on estrogenic effect of bisphenol A and antiestrogenic of selenium.