PI3K/Akt通路在EGFR/KRAS不同遗传背景NSCLC细胞对TRAIL敏感性中的作用

Effect of PI3K/Akt Pathway Inhibition on TRAIL-Induced Apoptosis in Human Non-small Cell Lung Cancer Cells With EGFR Mutation and KRAS Mutation

[目的]探讨PI3K/Akt通路在肿瘤坏死因子相关凋亡诱导配体(tumor necrosis factor related apoptosis inducing ligand,TRAIL)诱导携带EGFR/KRAS不同基因表型的非小细胞肺癌(non-small cell lung cancer,NSCLC)细胞凋亡中的作用。[方法 ]CCK8法检测TRAIL对A549和PC9细胞活性的影响;Western blot检测TRAIL作用后Akt、p-Akt蛋白表达的变化。使用PI3K特异性抑制剂LY294002处理细胞,CCK8法检测对TRAIL抗细胞增殖活力的影响;流式细胞术检测对TRAIL诱导细胞凋亡和细胞周期影响。[结果]当TRAIL浓度<100 ng/ml时,A549和PC9细胞的存活率与对照组无明显差异。当TRAIL浓度分别为100 ng/ml[(64.29±11.39)%vs(100±12.07)%,t=6.900,P=0.020]、[(74.57±9.70)%vs(100±11.20)%,t=4.786,P=0.041]和500ng/ml[(48.85±10.92)%vs(100±12.07)%,t=13.390,P=0.006][(46.34±8.99)%vs(100±11.20)%,t=18.419,P=0.003]时,A549和PC9细胞存活率明显低于对照组。TRAIL以时间依赖的方式上调A549和PC9细胞内的p-Akt的水平。使用LY294002抑制PI3K/Akt通路活性能够明显增加TRAIL抑制A549细胞[(40.74±2.53)%vs(64.29±9.30)%,t=6.092,P=0.026]和PC9细胞[(42.38±3.40)%)vs(74.57±7.92)%,t=12.689,P=0.006]增殖的能力,诱导更多的A549细胞[(44.98±8.99)%vs(23.07±2.92)%,t=7.836,P=0.016)]和PC9细胞[(46.32±7.42)%vs(3.44±1.46)%,t=40.727,P=0.001)]凋亡,并使细胞周期更多地阻滞在G0/G1期[(73.60±3.43)%vs(60.20±5.48)%;(70.51±3.86)%vs(42.37±4.55)%](P均<0.05)。[结论]TRAIL引起的PI3K/Akt通路活化,可拮抗TRAIL的诱导凋亡作用。抑制PI3K/Akt活性可明显增强EGFR-TKI敏感的和EGFR-TKI不敏感的NSCLC细胞对TRAIL诱导凋亡的敏感性。

[Purpose] To explore the effect of PI3K/Akt pathway inhibition on TRAIL-induced apoptosis in human non-small cell lung cancer cells with EGFR mutation and KRAS mutation.[Methods] A549 and PC9 cells were treated with TRAIL under different concentrations. The drug sensitivity was estimated by CCK8 method. The expression of Akt phosphorylation was measured by Western blot. Then cells were treated with LY294002,an inhibitor of PI3K/Akt pathway,the flow cytometry（FCM） was used to analyze the alteration of cell cycle and apoptosis. The alteration of cell viability was measured by CCK8 method. [Results] No significant differences between A549,PC9 and the control were found when cells were treated with TRAIL of lower than 100ng/ml used CCK8 method. The cell viability of A549 and PC9 cells was significantly lower than the control when cells were treated with TRAIL（100ng/ml）[（64.29±11.39）% vs（100±12.07）%,t=6.900,P =0.020] [（74.57 ±9.70）% vs（100 ±11.20）%,t =4.786,P =0.041]. Similar results were observed when cells were treated with TRAIL（500ng/ml） [（48.85±10.92）% vs（100±12.07）%,t=13.390,P=0.006] [（46.34±8.99）% vs（100±11.20）%,t=18.419,P=0.003]. A549 and PC9 cells showed the increased level of Akt phosphorylation activated by TRAIL in a time-dependent manner. Treatment with LY294002 before TRAIL resulted in less cell viability [（40.74±2.53） % vs（64.29±9.30）%,t=6.092,P=0.026][（42.38±3.40）%） vs（74.57±7.92）%,t=12.689,P=0.006],more apoptosis [（44.98±8.99）%vs（23.07±2.92）%,t=7.836,P=0.016][（46.32±7.42）% vs（3.44±1.46）%,t=40.727,P=0.001] and more cell cycle arrest at G0/G1 phase [（73.60 ±3.43）% vs（60.20 ±5.48）%;（70.51 ±3.86）% vs（42.37 ±4.55）% ],t =6.487,P =0.023;t =14.702,P =0.005） than TRAIL-single treatment. [Conclusion] PI3 K /Akt activity promotes A549 and PC9 cells survival against TRAIL-induced apoptosis.The cytotoxic effect of TRAIL can be enhanced by inhibiting the Akt phosphorylation in TKI-sensitive and TKI-insensitive human non-small cell lung cancer cells.