表皮生长因子对胰岛素-PI3K信号通路的影响及机制  

Effect of epidermal growth factor on insulin-PI3K signaling pathway and potential mechansim involved

作　　者：胡先福[1] 叶火旺 信思易 何济满[1] 郭文[1] 

机构地区：[1]南方医科大学附属南方医院消化内科,广东省广州市510515

出　　处：《世界华人消化杂志》2015年第22期3592-3596,共5页World Chinese Journal of Digestology

基　　金：国家自然基金资助项目;No.81170743~~

摘　　要：目的:研究表皮生长因子(epidermal growthf actor,EGF)对胰岛素-磷脂酰肌醇3-激酶(PI3K)信号通路的影响及其可能涉及的机制.方法:肝癌细胞系Hep G2用含10%胎牛血清的DMEM培养.细胞刺激试验前过夜血清饥饿,EGF和胰岛素刺激不同的时间,裂解细胞后提取蛋白,Western blot检测相关信号蛋白水平.结果:胰岛素可以导致肝癌细胞系蛋白激酶B(Akt)的磷酸化.当EGF短时间刺激后,胰岛素对PI3K信号通路的调节没有受到明显的影响.当EGF刺激4 h后,胰岛素对Akt的激活效应受到抑制,而当Hep G2细胞转染质粒磷酸酶域突变型质粒p Sv EGFP-PTEN C124S或PI3K调节亚基的p85 N末端缺失序列p50后,EGF预先刺激产生的对Akt的抑制效应消失.结论:EGF和胰岛素的相互作用对肝癌细胞PI3K-Akt信号通路具有抑制效应,其抑制机制涉及到PTEN和调节亚基p85.当两基因突变后,这种抑制作用则消失.AIM：To examine the effect of epidermal growth factor（EGF） on the insulin-PI3 K signalling pathway and the potential mechanism involved.METHODS：HepG2 cells were cultured in Dulbecco’s modified Eagle’s medium（DMEM）containing 10%fetal calf serum with the addition of L-glutamine.After overnight serum starvation,cells were stimulated with EGF or insulin for different periods of time.Cell protein expression was determined by Western blot.RESULTS：Insulin stimulation caused Akt phosphorylation in HepG2 cells.Prestimulation with epidemimal growth factor for 30 min had no significant effect on PI3 K signalling.In contrast,prestimulation with EGF for 4 h inhibited insulin induced activation of p-Akt.When cells were transfected with phosphatase and tensin homolog deleted on chromosome10（PTEN） mutant C124 S or N-terminal deleted p85,EGF induced inhibition of phospho-Akt was reversed.CONCLUSION：Interaction between EGF and insulin inhibits PI3K-Akt activation.The underlying mechanism involves PTEN and regulatory subunit p85.Mutations of PTEN and p85 reverse the inhibition.

关 键 词：表皮生长因子 胰岛素 人肝癌细胞系HEPG2 PI3K信号通路 

分 类 号：R73-3[医药卫生—肿瘤]