摘要：Cardiotoxin III (CTX III), a 60-amino acid basic polypeptide isolated from Naja venom, showed potential therapeutic activity toward cancer cells. Here we report that CTX III inhibited proliferation of human leukemia K562 cells by G2/M phase arresting and apoptosis which was associated with the activation of caspase-8 and cytochrome c release as well as the p38 and c-Jun N-terminal protein kinase (JNK) phosphorylation signaling pathway. We further demonstrated that daily administration of CTX III for 2 d to chicken chorioallantoic membrane (CAM) bearing tumours derived from the CAM at E10 administration of K562 cells resulted in inhibition of the tumours in vivo . Importantly, this in vivo inhibition was also associated with caspase-8 activation and cytochrome c release. Our results suggest that CTX III-induced apoptosis is mediated via the p38 and JNK pathway as well as the caspase-8-dependent Bid-Bax pathway in human K562 cells.
