中文摘要：

目的探讨HER-2／neu特异性小干扰核糖核酸（siRNA）对高表达HER-2／neu的人胶质瘤细胞系U251MG和T98G增殖的影响及其可能机制。方法脂质体介导HER-2／neusiRNA转染体外常规培养的U251MG和T98G细胞，同时设脂质体为对照组。转染后3d实时定量PCR和免疫印迹实验检测HER-2／neumRNA和蛋白的表达；四甲基偶氮唑盐（MTT）比色法检测转染后3、4d细胞增殖率的变化；免疫印迹实验检测转染后3d细胞蛋白激酶B（AKT）、磷酸化AKT、磷酸化叉头转录因子（FOX01）、p27、CyclinD1蛋白的表达。结果与脂质体组比较，HER-2／neusiRNA组U251MG、T98G细胞转染后3dHER-2／neumRNA和蛋白的表达均下降，转染后3、4d细胞增殖率均下降，转染后3d细胞磷酸化AKT和磷酸化FOX01水平降低、p27蛋白表达增多、CyclinDl蛋白表达减少，差异均有统计学意义（P〈0．05）。结论HER-2／neusiRNA转染人胶质瘤细胞系U251MG和T98G后明显抑制细胞增殖，可能与抑制AKT／FOX01信号通路．调控下游基因p27、CyclinD1蛋白的表达有关。

英文摘要：

Objective To investigate the effect of HER-2/neu siRNA on proliferation of human glioma cell lines U251MG and T98G which over-express HER-2/neu, and explore its mechanism. Methods Liposome-mediated HER-2/neu siRNA was transfected into human glioma cell lines U251MG and T98G; lipofectin group was established as controls. The mRNA and protein levels of HER-2/neu were detected by real-time PCR and Western blotting 3 d after the transfection. The proliferation of glioma cells was investigated using methyl thiazolyl tetrazolium （MTT） assay 3 and 4 d after the transfeetion. The effects of HER-2/neu siRNA on AKT/FOXO1 pathway and protein expression of p27 and Cyclin D1 were studied using Western blotting. Results HER-2/neu mRNA and protein expressions in the transfected U251MG cells were decreased to （28.833 ±4.174）% and （22.167 ± 1.955）% while those in cells of the lipofectin group were （92.067±5.698）% and （96.100±1.682）%, respectively, with significant differences （P=0.000, 0.001）. HER-2/neu mRNA and protein expressions of the transfected T98G cells were decreased to （28.067±6.165）% and （12.433±8.864）% while those in the untransfected cells were （96.000±5.110）% and （94.333±3.215）%, respectively, with significant differences （P=0.001, 0.008）. Three d after the transfection, the rates of proliferation in the transfected T98G and U251MG cells were （58.467±5.561）% and （63.933±5.363）%, respectively; 4 d after the transfection, the rates of proliferation in the transfected T98G and U251MG cells were （57.500±4.770）% and （60.167±3.253）%, respectively; an obvious decrease was noted as compared them with cells of the lipofectin group （P=0.020, 0.023, 0.021, 0.008）. Cyclin D1 expression was decreased, while p27 protein expression was up-regulated in the transfected cells as compared with those in cells of the lipofectin group （P〈0.05）. Moreover, the levels of phosphorylated AKT and phosphorylated FOXO1 were decreased in the transfected cells as com