Akt磷酸化在A549细胞抵抗rsTRAIL蛋白诱导细胞凋亡的研究

Akt phosphorylation and mechanism of TRAIL-resistance in A549 cells

目的:研究Akt磷酸化抵抗rsTRAIL蛋白诱导肺癌A549细胞株凋亡的作用机制。方法:rsTRAIL蛋白和哌立福新单独和联合作用于细胞株A549,Western blot检测A549细胞中Akt磷酸化水平变化、c-FLIPLL表达水平变化、caspase-8蛋白活化变化情况。流式细胞术进行细胞凋亡检测。MTT法检测A549细胞增殖率。结果:Western blot结果显示,rsTRAIL蛋白可以导致A549细胞中Akt磷酸化水平的增加,哌立福新能够抑制A549细胞中Akt的磷酸化水平及c-FLIPLL表达水平,增强A549细胞中caspase-8的活化。哌立福新能提升rsTRAIL蛋白诱导A549细胞的细胞凋亡率至(76.5±3.02)%和杀伤活性到(83.2±2.54)%。结论:Akt磷酸化是导致A549细胞对抵抗rsTRAIL诱导细胞凋亡的重要原因,抑制其活性可以促进rsTRAIL蛋白发挥抗NSCLC的活性。

Objective：To investigate mechanism of TRAIL-resistance in A549 cells （ a cell line of non-small cell lung carcino-ma cells） due to Akt phosphorylation .Methods：A549 cells were treated with Akt inhibitor Perifosine and rsTRAIL protein individual-ly and in combination.The expressions of Akt phosphorylation（p-Akt）,c-FLIPLL and caspase-8 were detected by Western blot.The apoptotic rate of the A549 cells treated was detected by flow cytometry and the cell proliferation was evaluated by MTT assay .Results：A549 cells showed the increased level of Akt phosphorylation mediated by rsTRAIL protein .Treatment with the Akt inhibitor Perifosine induced a suppression of Akt activation in A 549 cells and a concomitant decrease in the expression of c-FLIPLL .As a result, Perifosine significantly enhanced TRAIL-induced apoptosis rate of （76.5±3.02）%and cytotoxic rate of （83.2 ±2.54）%by promoting the activ-ity of caspase-8.Conclusion：Akt activity promotes A549cells survival against TRAIL-induced apoptosis and that the cytotoxic effect of rsTRAIL protein can be enhanced by modulating the Akt phosphorylation in human non -small cell lung carcinoma cells .