表皮生长因子受体和整合素通路交叉作用对胃癌细胞侵袭的影响

目的了解表皮生长因子受体(epidermal growth factor receptor,EGFR)和整合素信号通路在胃癌细胞SGC7901中的交叉反应和对细胞侵袭增殖的影响。方法使用EGF和Fn刺激SGC7901细胞,免疫沉淀和蛋白质电泳检测ERK、FAK和p130cas总蛋白和FAK Y397、p130cas Y410和ERK总酪氨酸磷酸化的改变;使用改良Boyden小室法检测胃癌细胞侵袭力;MTT法检测细胞增殖的改变;使用RNA干扰降低FAK表达,观察FAK低表达对交叉反应和胃癌侵袭增殖的影响。结果 ERK、FAK和p130cas总蛋白在刺激前后无变化(P>0.05)。Fn刺激后,ERK总酪氨酸磷酸化增强了2.90倍(P<0.05),细胞侵袭力增强了2.36倍(P<0.05),24 h MTT值升高了1.68倍(P<0.05);EGF刺激后,FAKY397磷酸化增强了2.75倍(P<0.05),p130cas Y410磷酸化增强了4.33倍(P<0.05),细胞侵袭力增强了1.50倍(P<0.05),24 h MTT值分别升高了1.76倍(P<0.05)。转染FAK siRNA组细胞,FAK Y397磷酸化表达只有对照组的0.30倍(P<0.05);Fn刺激后,ERK总磷酸化表达只有对照组的0.66倍(P<0.05),细胞侵袭力只有对照组的0.37倍(P<0.05),24 h MTT值只有对照组的0.63倍(P<0.05);EGF刺激后,p130 Y410磷酸化只有对照组的0.49倍(P<0.05),细胞侵袭力只有对照组的0.48倍(P<0.05),24 h MTT值只有对照组0.77倍(P<0.05)。结论 EGFR和整合素信号在胃癌细胞中发生交叉反应,FAK是其中的关键信号分子,阻断FAK表达可以有效抑制两条信号通路引起的胃癌细胞侵袭和增殖。

Effect of crosstalk between EGFR and integrin signaling pathways on invasion of gastric cancer cells

Objective To understand crosstalk between epidermal growth factor receptor(EGFR) and integrin signaling pathways and effect of the crosstalk on cell invasion and proliferation in human gastric cancer cell SGC7901.Methods Human gastric cancer cells SGC7901 were stimulated with EGF and Fn,respectively.Protein expressions of total and phosphorylated ERK,FAK(Y397) and p130cas(Y410) were measured by immunoprecipitation and Western blotting.Invasion and proliferation of gastric cancer cells were detected by modified Boyden chamber and MTT assay.RNA interference was used to block FAK expression,and the effect of low level of FAK on cross reaction,cell invasion and proliferation were testified.Results Expressions of total ERK,FAK and p130cas had no significant change before and after stimulation.After stimulation with Fn,tyrosine phosphorylated ERK increased 2.90 times(P<0.05);cell invasiveness enhanced 2.36 times(P<0.05);and MTT value at 24 h increased 1.68 times(P<0.05).After stimulation with EGF,phosphorylated FAK(Y397) increased 2.75 times(P<0.05);phosphorylated p130cas(Y410) increased 4.33 times(P<0.05);cell invasiveness increased 1.50 times(P<0.05);and MTT value at 24 h increased 1.76 times(P<0.05).In cells transfected with FAK siRNA,FAK(Y397) phosphorylation was only 0.30 times of the control(P<0.05).After stimulation with Fn,ERK tyrosine phosphorylation was only 0.66 times of the control(P<0.05);cell invasiveness was only 0.37 of the control(P<0.05);and MTT value at 24 h was only 0.63 times of the control(P<0.05).After stimulation with EGF,p130(Y410) phosphorylation was only 0.49 times of the control(P<0.05);cell invasiveness was only 0.48 times of the control(P<0.05);and MTT value at 24 h was only 0.77 times of the control(P<0.05).Conclusion There is a crosstalk between EGFR and integrin signaling pathways in human gastric cancer cell SGC7901.FAK,which is a key module in the crosstalk,its inhibition can reduce invasion and proliferation of human gastric cancer cells induced by crosstalk between EGFR and integrin.