胰岛素样生长因子1（IGF-I）通过PI-3K/Akt途径对结肠癌细胞凋亡的影响

目的：探讨胰岛素样生长因子-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凋亡率的影响及其凋亡抑制蛋白survivin表达水平的变化。方法：培养结肠癌SW480细胞株,实验分成三组：未加IGF-I空白组、IGF-I刺激组、IGF-I＋LY294002阻断组,检测阻断剂LY294002是否阻断PI-3K/Akt通路（Western Blot检测三组P-Akt表达情况）;Western Blot及免疫荧光观察三组survivin蛋白表达变化;MTT法检测细胞增殖活性,流式细胞术检测细胞凋亡情况。结果：Western blot结果显示LY294002可抑制IGF-I诱导的p-Akt的表达（P〈0.05）;阻断IGF-I诱导的PI-3K/Akt通路后MTT显示结肠癌细胞SW480增殖抑制率升高（P〈0.05）,流式细胞术分析显示凋亡率明显上升（P〈0.05）;Western blot及免疫荧光结果显示LY294002可抑制IGF-I诱导的survivin的表达（P〈0.05）。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 on Apoptosis of Colon Cancer Cell Through Signaling Pathway of PI-3K/Akt

Objective：To investigate the effect of IGF-I on the apoptosis rate,and the expression of survivin through the signaling pathway of PI-3K/Akt in colon cancer cell line SW480.Methods：The experiment was divided into three groups：not-added IGF-I blank group,added IGF-I stimulate group,added IGF-I and the specific inhibitor LY294002 block group,detected the specific inhibitor LY294002 could inhibited the signaling pathway of PI-3K/Akt（Western blot was used to detecte the expression of P-Akt of three groups）;Western blot and cell immunofluorescence were used to detecte the expression of survivin protein of three groups;SW480 cells prolifera-tion was measured by MTT assay.The apoptosis rate was analyzed by flow cytometry（FCM）.Result：When the signaling pathway of PI-3K/Akt was inhibited by specific inhibitor LY294002,the expression of p-Akt and survivin proteins were obviously lower than the IGF-I stimulate group（P0.05）;MTT showed that SW480 cells proliferation was significantly inhibited after the signaling pathway of PI-3K/Akt was inhibited（P0.05）,The flow cytometry indicated that the apoptosis rate of SW480 cells could markedly upgrade（P0.05）.Conclusion：IGF-I could induce survivin expression through the PI-3K/Akt in colon cancer line SW480,then lead to the inhibition of its apoptosis.