自噬和凋亡在木犀草素诱导肺癌A549细胞死亡中的作用

The role of autophagy and apoptosis in the death of human lung cancer adenocarcinoma A549 cell induced by luteolin

目的:探讨自噬和凋亡在木犀草素诱导的人肺腺癌A549细胞死亡中的作用及机制。方法:采用MTT法观察木犀草素对肺癌A549细胞生长的抑制作用的干预效果,Hoechst 33258染色实验观察细胞形态学变化,采用Western blotting检测细胞凋亡相关蛋白Bcl-2相关的X蛋白质(Bcl-2-Associated X protein,Bax)、B淋巴细胞瘤-2基因(B-cell lymphoma-2,Bcl-2)及自噬相关蛋白Beclin1、微管相关蛋白1轻链3(Microtubule-associated Protein 1 light chain 3,LC3)的表达水平改变,同时检测Caspase-3活性的变化。结果:不同浓度的木犀草素对肺癌细胞的生长均有抑制作用,木犀草素组与木犀草素+3-甲基腺嘌呤(3-MA)组均呈现典型的凋亡细胞形态,且木犀草素+3-MA组细胞的凋亡率明显高于木犀草素组。增加木犀草素浓度后,Bax表达明显增加,而Bcl-2的表达明显减少,自噬特异性蛋白LC3-II、Beclinl表达也明显增多。在木犀草素+3-MA组,LC3-II蛋白表达下降,Caspase-3的活性明显高于木犀草素组。结论:自噬和凋亡均参与了木犀草素诱导的A549细胞死亡过程,且自噬拮抗木犀草素诱导的A549细胞死亡。

Objective:To investigate the role and mechanism of autophagy and apoptosis in the death of human lung cancer adenocarcinoma A549 cell induced by luteolin.Methods:MTT assay was used to observe the intervention effect of luteolin on the growth inhibition of lung cancer A549 cells.Hoechst 33258 staining experiment was used to observe the morphological changes of cells.The changes in the expression levels of apoptosis related proteins Bax and Bcl-2,and autophagy related proteins Beclin1 and LC3 were detected by Western blotting,and the changes in the activity of Caspase-3 were detected at the same time.Results:Luteolin at different concentrations could inhibit the growth of lung cancer cells.Typical apoptotic cell morphology was found in both the luteolin group and the L3MA group,and the apoptosis rate in the L3MA group was significantly higher than that in the luteolin group.After increasing the concentration of luteolin,the expression of Bax was significantly increased,while the expression of Bcl-2 was significantly decreased.The expression of autophagy specific proteins LC3-II and Beclinl were also significantly increased.LC3-II protein expression was decreased in the L3MA group,and Caspase-3 activity was significantly higher than that in the L3MA group.Conclusions:Both autophagy and apoptosis are involved in the process of luteolin-induced A549 cell death,and autophagy antagonizes the luteolin-induced A549 cell death.