PKGⅡ对胃癌SGC-7901细胞增殖相关的MAPK/ERK下游信号分子的抑制作用  

PKGⅡ inhibits downstream targets of proliferation-related MAPK/ERK in gastric cancer cell line SGC-7901

作　　者：桑建荣[1] 陈永昌[1] 李月英[1] 陶燕[1] 邵根宝[1] 

机构地区：[1]江苏大学基础医学与医学技术学院生理学系,江苏镇江212013

出　　处：《肿瘤》2012年第11期862-867,共6页Tumor

基　　金：国家自然科学基金资助项目(编号:81001100)

摘　　要：目的:探讨cGMP依赖性蛋白激酶Ⅱ(cGMP-dependent protein kinaseⅡ,PKGⅡ)对人胃癌SGC-7901细胞增殖相关的丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)/细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)下游核糖体S6激酶1(ribosomal S6 kinase1,RSK1)和原癌基因c-Jun、c-Fos的作用。方法:用腺病毒Ad-LacZ和Ad-PKGⅡ感染SGC-7901细胞,使细胞高表达PKGⅡ;用特异性PKGⅡ激活剂8-pCPT-cGMP[8-(p-chlorophenylthio)-cyclic GMP]作用于感染了腺病毒的细胞,再用表皮生长因子(epidermal growth factor,EGF)进行刺激。MTT法检测PKGⅡ对EGF刺激引起的SGC-7901细胞增殖的影响,RT-PCR法和蛋白质印迹法分别检测PKGⅡ对EGF引起的SGC-7901细胞中c-Jun、c-FosmRNA和p-RSK1、c-Jun、c-Fos蛋白表达的影响,免疫荧光显微镜下观察p-RSK1在SGC-7901细胞核内的分布情况。结果:8-pCPT-cGMP作用于感染了Ad-PKGⅡ的SGC-7901细胞后,EGF对SGC-7901细胞的增殖促进作用和EGF诱导的c-Jun、c-FosmRNA和蛋白的表达受到抑制,RSK1(Ser380)磷酸化水平明显降低;EGF刺激后,SGC-7901细胞核内大量累积p-RSK1,8-pCPT-cGMP作用后细胞核内p-RSK1减少。结论:激活的PKGⅡ可有效抑制EGF诱导的胃癌细胞的增殖、RSK1Ser380位点的磷酸化、p-RSK1在细胞核内的累积以及原癌基因c-Jun和c-Fos的表达。Objective： To investigate the effect of PKGⅡ （cGMP-dependent protein kinase Ⅱ） on cell proliferation-related MAPK （mitogen-activated protein kinase）/ERK （extracellular signal-regulated kinase） downstream targets RSK1 （ribosomal S6 kinase 1） and proto-oncogenes c-Jun and c-Fos in gastric cancer SGC-7901 cells. Methods： Gastric cancer SGC-7901 cells were infected with Ad-LacZ and Ad-PKG Ⅱ adenovirus, and then the PKGⅡ was overexpressed in SGC-7901 cells. These cells were treated with PKGⅡ specific activator — 8-pCPT-cGMP [8-（p-chlorophenylthio）-cyclic GMP], and then they were stimulated with EGF （epidermal growth factor）. The proliferation of SGC-7901 cells was examined by MTT method, and the mRNAs expression levels of c-Jun and c-Fos and the protein expression levels of p-RSK1, c-Jun and c-Fos were examined by RT-PCR and Western blotting, respectively. The nuclear accumulation of p-RSK1 was observed under an immunofluorescence microscope. Results： EGF-induced increase of cell proliferation and the elevation of expressions of c-Jun and c-Fos mRNAs and proteins as well as p-RSK1 （Ser380-） protein in SGC-7901 cells which were infected with PKGⅡ were significantly inhibited after treatment with 8-pCPT-cGMP. The phosphorylation of RSK1 （Ser380） was decreased, and the accumulation of p-RSK1 （Ser380） in nuclei of SGC-7901 cells was increased after stimulation with EGF, while it was decreased after treatment with 8-pCPT-cGMP. Conclusion： Activated PKGⅡ can inhibits the proliferation of gastric cancer cells, phosphorylation of RSK1 （Ser380）, nuclear accumulation of p-RSK1（Ser380） and the expressions of c-Jun and c-Fos genes which were induced by EGF.

关 键 词：胃肿瘤 细胞增殖 免疫荧光检测 PKG Ⅱ 细胞 SGC-7901 

分 类 号：R735.2[医药卫生—肿瘤] R730.5[医药卫生—临床医学]