胃泌素通过JAK2/STAT3信号通路调控胃癌细胞上皮间质转化

Gastrin modulates procedure of epithelial to mesenchymal transition through JAK2/STAT3 pathway in human gastric cancer cells

目的 :观察外源性17肽胃泌素(gastrin-17,G-17)对人胃癌SGC-7901细胞E-钙黏素(E-Cadherin)及N-钙黏素(N-Cadherin)表达的影响并对相关机制进行初步探究。方法 :体外培养胃癌SGC-7901细胞,使用G-17与胃泌素受体(cholecystokinin2 receptor,CCK2R)特异性抑制剂YM022处理胃癌细胞24 h后,Western blot检测E-Cadherin和N-Cadherin的表达;分别转染针对CCK2R的si RNA和过表达质粒,观察G-17处理对E-Cadherin和N-Cadherin表达的影响;Western blot检测G-17/CCK2R对JAK2/STAT3信号转导通路的活化情况;在分别使用JAK2特异性抑制剂AG490抑制JAK2/STAT3信号转导通路的激活或降低STAT3表达后,观察G-17对E-Cadherin和N-Cadherin表达的影响。结果:Western blot显示外源性G-17处理能降低SGC-7901胃癌细胞E-Cadherin的表达并上调N-Cadherin的表达,同时活化JAK2/STAT3信号转导通路,且这种效应能够被CCK2R特异性抑制剂YM022或si RNA所阻断,提示上述效应是由CCK2R所介导的。当使用AG490抑制JAK2/STAT3信号转导通路或下调STAT3表达后,G-17诱导的E-Cadherin下调以及N-Cadherin上调效应会部分被逆转。结论:外源性G-17可通过作用于胃癌SGC-7901细胞的CCK2R,进而激活JAK2/STAT3信号转导通路,下调E-Cadherin蛋白表达,上调N-Cadherin蛋白表达,诱导胃癌SGC-7901细胞的上皮间质转化。

Objective： To observe the effect of exogenous gastrin-17 on the expression of E-Cadherin and N-Cadherin in human gastric cancer cell line SGC-7901,and discuss the related mechanisms.Methods： SGC-7901 cells were pre-treated with or without YM022 for 1 h and then incubated with G-17 for 30 min to detect the activation of JAK2/STAT3 signaling pathway,for 24 h to detect the expression of E-Cadherin and N-Cadherin,respectively by western blot analysis.SGC-7901 cells were transfected with CCK2R-si RNA or full-length c DNA of human CCK2R（pCMV6-CCK2R）,followed by G-17 treatment to detect the expression of p-STAT3,E-Cadherin and N-Cadherin.Cells were pre-treated with AG490 for 1 h or knockdown of STAT3 with si RNA,then incubated with G-17 for 24 h to evaluate the expression of E-Cadherin and N-Cadherin.Results： Western blot assay showed the exogenous G-17 significantly decreased the expression of E-Cadherin and increased the expression of N-Cadherin,meanwhile,activated the JAK2/STAT3 signaling pathway.Specific antagonist or si RNA against CCK2R partly blocked gastrin-induced activation of STAT3 and the expression of E-Cadherin and N-Cadherin,which suggested the effect of gastrin was CCK2R dependent.Specific inhibitor of JAK2/STAT3 signaling pathway AG490 and si RNA against STAT3 partly attenuated the effect of gastrin on the expression of E-Cadherin and N-Cadherin.Conclusion： Gastrin acting on the cholecystokinin2 receptor,down-regulates expression of E-Cadherin and up-regulates the expression of N-Cadherin,via activation of JAK2/STAT3 signaling pathway induced EMT in human gastric cancer cells.