S100A4基因沉默对人胃癌细胞中P13K/AKT/mTOR信号通路及VEGF表达的影响

Effects of of S100A4-knockdown on PI3K/AKT/mTOR signaling pathway and VEGF expression in human gastric cancer cells

目的探讨用RNA干扰技术沉默人胃癌细胞株MGC-803细胞中钙结合蛋白S100A4的基因,对PI3K/AKT/mTOR信号通路及血管内皮生长因子(vascular endothelial growth factor,VEGF)表达的影响及与胃癌血管生成的关系。方法采用RNA干扰技术将针对S100A4和非特异性阴性对照序列的siRNA分别转染至人胃癌MGC-803细胞,利用Real-time RT-PCR和Western blot检测S100A4基因和蛋白的表达,筛选S100A4基因沉默组和阴性对照组细胞。采用Western blot方法检测Akt、mTOR磷酸化水平和VEGF蛋白表达情况。结果成功建立S100A4基因沉默的人胃癌MGC-803细胞。S100A4基因沉默的MGC-803细胞中Akt、mTOR磷酸化水平明显降低,同时VEGF蛋白表达亦显著降低。结论 S100A4能通过PI3K/AKT/mTOR信号通路上调VEGF表达,进而促进胃癌血管生成。

Objective To investigate the effects of RNA interfering-mediated S100 A4 knockdown on the expressions of PI3 K/AKT/mTOR signaling pathway and VEOF in human gastric cancer cell lines MGC-803. Methods The S100 A4-siRNA was transfected into human gastric cancer cells MGC-803. The expressions of S100 A4 mRNA and protein were detected by Real-time RT-PCR and Western blot to select S100 A4 knockdown and negative control cells. The levels of P-Akt（Ser473）、Akt、P-mTOR（Ser2448）、mTOR and VEGF proteins were determined by Western blot. Results The human gastric cancer MGC-803 cells of S100 A4 knockdown were successfully established. Compared with the control group, the levels of S100 A4 gene and protein were significantly decreased. In MGC-803 cells of S100 A knockdown, the expression levels of P-Akt（Ser473）, P-mTOR（Ser2448） and VEGFM were decreased significantly. Conclusion S100 A could upregulate the expression of VEGF through the PI3 K/AKT/mTOR signaling pathway, and affect the angiogenesis of human gastric cancer.