INDUCTION OF DIFFERENTIATION AND APOPTOSIS BY SODIUM SELENITE IN HUMAN COLONIC-CARCINOMA CELLS (HT29)

To explore the mechanism(s) by which selenium (Se) exerts its cancer c hemopreventive activity, we studied the effect of selenite (0-100 mu M ) on cell growth, viability, differentiation, detachment, DNA fragment ation and apoptosis in human colonic carcinoma cells (HT29). Selenite (greater than or equal to 5 mu M) decreased cell growth, increased cel l detachment and decreased intracellular levels of reduced glutathione (GSH), whereas greater than or equal to 10 mu M selenite induced cell differentiation and apoptosis. The chemopreventive effects of selenit e may be related in part to the generation of reactive oxygen species (ROS) resulting from the reaction between selenite and GSH. (C) 1997 E lsevier Science Ireland Ltd.