PI3K/AKT信号通路参与AG1478对肺癌细胞中FOXO3a分子的上调及核转位

摘要

目的:探讨表皮生长因子酪氨酸激酶抑制剂(EGFR-TKI) AG1478对非小细胞肺癌细胞(NSCLC)中叉头转录因子O3a (FOXO3a)表达及其在细胞核质分布的调控及分子机制.方法:Western blot法检测AG1478及EGFR下游信号通路抑制剂LY294002、U0126、AG490作用后A549细胞中FOXO3a的表达及其在细胞核质分布情况.瞬时转染AKT、FOXO3a小干扰RNA(siRNA),RT-PCR及Western blot检测转染效率及相关蛋白的表达改变.结果:AG1478呈时间依赖性诱导FOXO3a表达上调并促进其核转位.与U0126、AG490相比,PI3 K/AKT信号通路抑制剂LY294002呈时间依赖性抑制p-FOXO3a的表达,促进其核转位；沉默AKT后,p-AKT及p-FOXO3a分子的表达明显下调.结论:AG1478可能通过PI3 K/AKT信号通路上调FOXO3a的表达并促进其核转位,进而下调FOXM1及下游增殖蛋白的表达,抑制肺癌细胞的增殖,提示FOXO3a为肺癌治疗及药物开发的重要靶点.%Objective:To investigate the effcts on expression and distribution of FOXO3a genes by EGFR-TKI AG1478 in non-small cell cancer(NSCLC) cell lines.Methods:Human lung cancer cells were treated with different concentrations of AG1478 and EGFR signal pathway related inhibitors:U0126,LY294002,AG490.Western blot was used to examine the expression and the nucleus or cytoplasm distribution of FOXO3a.AKT siRNA and FOXO3a siRNA were designed and transfected into H1650 cells.RT-PCR and Western blot were employed to determine the transfection efficiency.Results:Increasing trends for the expression and nuclear translocation of FOXO3a by AG1478 were showed to be time dependent.Compared to U0126 and AG490,LY294002 significantly inhibited the expression of p-FOXO3 and induced its nuclear translocation.AKTsiRNA depleted the expressions of p-AKT and p-FOXO3a.Conclusion:The expression and nuclear translocation of FOXO3a was significantly induced by AG1478 via PI3K/AKT pathway in NSCLC cell lines and the expression of FOXM1 and its targets were repressed to inhibit cell proliferation.Suggesting that FOXO3a could be a potential target for the cancer therapy and drug exploitation of NSCLC.