自噬在吉西他滨诱导肺癌细胞A549凋亡中的作用及其相关机制

  目的  研究自噬对吉西他滨(gemcitabine, GEM)诱导的肺癌细胞A549凋亡的影响并探讨其可能机制。  方法  MDC染色后采用荧光显微镜对自噬进行形态观察; 以CCK8检测3-MA抑制自噬前后经吉西他滨诱导的A549细胞存活率; RT-PCR检测自噬相关基因Beclin-1表达的变化。Western blot分别检测自噬相关性蛋白Beclin-l及凋亡活化蛋白Caspase-3的变化。  结果  吉西他滨可诱导肺癌细胞A549产生自噬, 自噬在基因及蛋白水平表达均增加; 3-MA和吉西他滨联合用药可增强肺癌A549细胞凋亡。  结论  吉西他滨诱导肺癌细胞A549凋亡的过程中自噬可能起到保护作用, 3-MA特异性抑制自噬后可增强吉西他滨诱导的A549细胞凋亡。 

Effect of Autophagy on Gemcitabine-induced A549 Lung Cancer Cell Death and Relevant Mechanisms

  Objectives  To investigate the mechanism and effects of autophagy on gemcitabine-induced A549 lung cancer cell death.  Methods  Quantitative analysis of autophagy after monodansylcadaverine(MDC) staining was performed using fluorescence microscopy. The cell viability of A549 cells after gemcitabine treatment in the presence or absence of autophagy inhibition was determined using cholecystokinin octapeptide(CCK8).Real-time polymerase chain reaction(RT-PCR) was used to measure the expression of the au-tophagy -related gene Beclin-1.Western blot analysis was used to determine the BecJin-l and caspase-3 protein levels.  Results  Autophagy is involved in the gemcitabine-induced A549 lung cancer cell death.The levels of both autophagy-related genes and proteins are increased. In addition, inhibition of autophagy promoted apoptosis in the A549 lung cancer cells.  Conclusion  Autophagy protects A549 lung cancer cells against gemcitabine-induced apoptosis.Moreover, cell apoptosis can be enhanced by the inhibition of autophagy.