自噬在眼镜蛇神经毒素诱导A549细胞死亡中的作用

BACKGROUND AND OBJECTIVE: It has been proven that cobrotoxin has anti-tumor effect while its role in lung cancer is rarely studied. The aim of this study is to assay the anti-tumor effect of cobrotoxin in cell line A549, and also to explore its possible mechanism related to autophagy and P38-MARK pathway. METHODS: Using MTT method to observe the inhibition effect of cobrotoxin on the growth of adenocarcinoma cell A549 and human lung fibroblast cell HFL1, as well as on that of A549 pretreated with 3-MA and SB203580, which are the inhibitor of autophagy and P38-MARK pathway respectively. Cell colony tablet cloning experiment was executed to detect the effect of cobrotoxin on colony formation of A549. Determining the protein levels of beclin-1, LC3, p38 and pP38 in A549 by Western blot after cells were exposed to cobrotoxin, or to cobrotoxin combined with either 3-MA or SB203580. RESULTS: All of different concentrations of cobrotoxin inhibited the growth of A549, but had no obvious effect on that of HFL1. After treating with 3-MA or SB203580, the suppress effect of cobrotoxin on A549 reduced. What's more, different concentrations of cobrotoxin all significantly suppressed the colony formation of A549. The expression of beclin-1 and pP38 in A549 increased obviously after exposure to cobrotoxin, and also the ratio of LC3 Ⅱ to LC3 Ⅰ amplified with a dose-dependant manner, but P62 decreased. The protein level of beclin-1 and the ratio of LC3 Ⅱ to LC3 Ⅰ in cells pretreated with 3-MA were reduced, while that of p62 was increased. Also, in cells that treated with SB203580 before exposed to cobrotoxin, the expression of beclin-1, pP38 and the ratio of of LC3 Ⅱ to LC3 Ⅰ were reduced, but the expression of P62 increased. CONCLUSION: Cobrotoxin can suppress the growth of A549 in vitro. And the activating of P38-MARK pathway, then upregulating autophagy, was involved in cobrotoxin induced anti-tumor process.