[目的]探讨PI3K/Akt通路在肿瘤坏死冈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Ak1 、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.

Objective To explore the effect of inhibiting Akt phosphorylation on tumor necrosis factor related apoptosis inducing ligand (TRAIL)-induced apoptosis of human non-small cell lung cancer (NSCLC) H1299 cells with wild type EGFR and KRAS.Methods The TRAIL-induced apoptosis was examined by the Annexin V-FITC/PI.The expressions of TRAIL-activated Akt phosphorylation and p-Akt were measured by Western blot.After cells were treated with LY294002, an inhibitor of PI3K-Akt pathway, Annexin V-FITC/PI and Western blot were used to analyze the alteration of TRAIL-induced apoptosis and Akt phosphorylation, respectively.Results H1299 cells were not sensitive to TRAIL-induced apoptosis.When TRAIL concentration was 100 ng/ml, the apoptosis rate of the test group was significantly higher than that of the control group [(15.06±1.29) ％ vs (3.56±0.50) ％, t =66.953, P =0.000].When TRAIL concentration was 500 ng/ml, the difference was not statistically significant compared with apoptosis rate of 100 ng/ml TRAIL group [(18.65±2.09) ％ vs (15.06±1.29) ％, t =2.423, P =0.136].The expression level of Akt phosphorylation in H1299 cells was increased by TRAIL in a time-dependent way.When cells were pretreated with LY294002, TRAIL-induced Akt phosphorylation was suppressed to baseline level.At the same time, the apoptosis rate in LY294002-treated group was significantly higher than that in TRAIL group [(41.65±4.62) ％ vs (15.82±0.61) ％, t =39.028, P =0.001].Conclusions TRAIL-induced Akt phosphorylation can antagonize TRAIL-induced apoptosis.Inhibition of Akt phosphorylation can significantly enhance the sensitivity of NSCLC H1299 cells with wild type EGFR and KRAS to TRAIL-induced apoptosis.

[目的]探讨TRAIL与舒尼替尼(sunitinib)体外不同用药方式下对表皮生长因子受体酪氨酸激酶抑制剂(EGFR-TKI)抵抗的NSCLC A549细胞的抗肿瘤活性及其机制.[方法]实验分为对照组、TRAIL组、舒尼替尼组、TRAIL联合舒尼替尼组(T+S)、TRAIL序贯舒尼替尼组(T→S)和舒尼替尼序贯TRAIL组(S→T).CCK8法检测TRAIL和舒尼替尼对A549细胞的生长抑制作用;流式细胞术检测TRAIL和舒尼替尼作用后细胞周期变化及诱导的细胞凋亡;Western blot检测TRAIL和舒尼替尼作用后Akt、p-Akt蛋白表达的变化.[结果]T+S组及T→S组的抗增殖作用及诱导细胞凋亡的能力明显优于TRAIL组、舒尼替尼组及S→T组(P均＜0.05).细胞周期显示,TRAIL和舒尼替尼均能使细胞周期阻滞于G0/G1期,T+S组、T→S组对G0/G1期的阻滞作用明显增强.Western blot结果显示,TRAIL单独作用于A549细胞能明显上调p-Akt的表达,而舒尼替尼能下调p-Akt的表达;T+S组、T→S组、S→T组p-Akt的表达明显减少.[结论]舒尼替尼通过抑制TRAIL诱导的PI3K/Akt通路活化,增加TRAIL诱导的A549细胞凋亡.此外,两药物对A549细胞周期的特异性阻滞作用,也是诱导凋亡增加的原因之一.