ROS production is required for follicle-stimulating hormone-induced Nrf2 activation in human epithelial ovarian cancer cells / 第二军医大学学报

ABSTRACT

Objective To observe the effects of follicle-stimulating hormone (FSH), reactive oxygen species (ROS) and its specific inhibitor on expression of Nrf2, so as to study the possible role of ROS signal pathway in FSH-mediated Nrf2 expression in Hey ovarian cancer cells.Methods The expression of Nrf2 in benign and malignant ovarian tissues was determined by immunohistochemical method. Ovarian cancer Hey cells were treated with different concentrations of FSH for different periods, and Western blotting analysis was used to examine Nrf2 protein expression. The generation of ROS was evaluated in Hey ovarian cancer cells by reactive oxygen species assay kit after stimulation with FSH (80 mIU/ml) for different periods. Hey cells were treated with different concentrations of H2O2 stimulation for 48 h or 150 mmol/L H2O2 after pretreatment with specific ROS inhibitors NAC for 48 h, then the expression of Nrf2 was examined by Western blotting analysis. Hey cells were pretreated with different concentrations of NAC for 1 h, and then incubated with FSH(80 mIU/ml) for 48 h and Nrf2 expression was observed.Results (1) Three of 10 benign ovarian cyst tissues had weak expression of Nrf2 protein; 42 (65.6%) of the 64 ovarian cancer tissues had Nrf2 protein expression (P=0.042). FSH up-regulated Nrf2 expression in a dose- and time-dependent manner. FSH promoted the generation of ROS in ovarian cancer cells. H2O2 promoted Nrf2 expression, which could be blocked by NAC. FSH-induced Nrf2 protein expression could be inhibited by NAC.Conclusion FSH can promote ROS generation and Nrf2 protein expression in ovarian cancer cells. Block of ROS pathway could inhibit FSH-induced overexpression of Nrf2, indicating FSH may regulate Nrf2 protein by ROS pathway, contributing to the development of ovarian cancer.