Bcl-X_L prevents serum deprivation-induced oxidative stress mediated by Romo1

B-cell lymphoma-extra large (Bcl-X_L) has been known to suppress serum deprivation-induced cell death, while reactive oxygen species modulator 1 (Romol) is responsible for a serum deprivation-induced increase in reactive oxygen species (ROS). Therefore, we investigated whether Bcl-X_L expression could inhibit the serum deprivation-induced increase in ROS and cell death, which are mediated by Romol. We found that Bcl-X_L expression effectively blocked serum deprivation- and Romol-triggered ROS generation. Bcl-X_L also inhibited apoptotic cell death induced by both serum deprivation and oxidative stress. From these results, we suggest that increased Bcl-X_L expression, which is observed in many cancer cells, confers resistance to oxidative stress in the cancer cells by suppressing Romol-mediated oxidative stress.