Capsaicin causes apoptosis of human small cell lung cancers cells via the TRPV6/calpain pathway (644.8)

Small cell lung cancer (SCLC) is characterized by aggressive clinical course and a dismal survival rate. The present study examines the apoptotic activity of capsaicin (the pungent ingredient of chili peppers) in human SCLC. We observed that capsaicin induced apoptosis in a panel of human SCLC in a concentration-dependent and time-dependent manner. Most importantly, capsaicin caused robust apoptosis in a panel of human SCLC cell lines, but did not affect normal human lung epithelial cells. The dietary administration of capsaicin decreased the growth H69 and DMS53 human SCLC tumors in nude mice and in chicken chorioallantoic membrane (CAM) models. The apoptotic activity of capsaicin was reversed with the generalized TRPV antagonist ruthenium red, indicating that TRPV receptors are involved in capsaicin induced apoptosis. However, antagonists to TRPV1, namely capsazepine and SB-366791, did not affect the apoptotic activity of capsaicin, suggesting the involvement of a TRPV1-independent mechanism. In contras...