胰岛素样生长因子1对结肠癌细胞凋亡的影响及其机制研究

目的研究胰岛素样生长因子1(IGF-I)通过磷酯酰肌醇3-激酶/蛋白激酶B(PI-3K/Akt)信号通路对结肠癌细胞株SW480凋亡率的影响及凋亡抑制蛋白survivin表达水平的变化。方法在培养结肠癌SW480细胞株时,采用不同浓度的IGF-I不同时间作用于SW480细胞,然后采用Western blot检测凋亡抑制蛋白survivin表达变化。100 ng/mL IGF-I作用于SW480细胞2 h内,Westernblot检测Akt的磷酸化表达变化;Akt特异性抑制剂LY294002处理前后,利用Western blot检测Akt磷酸化表达的变化,Western blot及细胞免疫荧光检测survivin表达的变化,流式细胞术检测细胞凋亡率的改变。结果IGF-I能上调SW480细胞的survivin表达,且其表达水平与IGF-I的作用时间、浓度呈依赖性(IGF-I作用SW480细胞不同时间后,survivin蛋白表达显著升高,并在12 h时达到峰值,所有实验组survivin蛋白的表达均显著高于对照组;IGF-I浓度为100 ng/mL时,survivin蛋白的表达达到顶峰);IGF-I快速激活SW480细胞中PI-3K/Akt信号通路(IGF-I作用SW480细胞15,30 min后,p-Akt蛋白的表达达到高峰);IGF-I能通过PI-3K/Akt信号通路上调SW480细胞survivin的表达;IGF-I能通过PI-3K/Akt信号通路抑制SW480细胞凋亡[利用流式细胞术检测空白组、刺激组、阻断组各组SW480细胞的凋亡率,分别为(5.18±0.415)%,(0.85±0.052)%,(3.15±0.411)%,各组之间差异有统计学意义(P0.05)]。结论IGF-I可通过PI-3K/Akt通路诱导survivin表达,从而抑制结肠癌细胞SW480的凋亡。

Effect of insulin-like growth factor-I (IGF-I) on |apoptosis of colon cancer cell and its mechanism

Objective To investigate the effect of IGF-I on the apoptosis and the expression of survivin through the signaling pathway of PI-3K/Akt in colon cancer cell line SW480.Methods When colon cancer cell line SW480 was culfured,Western blot was used to detect the expression of survivin protein in SW480 cells after they were stimulated by different concentrations of IGF-I for different lengths of time.The phosphorylation of Akt in SW480 cells was determined by Western blot after SW480 cells were stimulated by 100...