人表皮生长因子受体显性负性突变体诱导胃癌细胞发生G0/G1期阻滞

摘要

AIM; To explore the effect of dominant negative epidermal growth factor receptor (DNEGFR) on the cell cycle of human gastric cancer cells. METHODS: Two human gastric cancer cell lines were used in the study. The cells were divided into 6 groups, including untreated SGC-7901 cells (US group) , SGC-7901 cells stably transfected with pEGFP-N1 (ES group), SGC-7901 cells stably transfected with pEGFPNl-DNEGFR ( DS group), untreated NCI-N87 cells (UN group) , NCI-N87 cells stably transfected with pEGFP-N1 (EN group) , and NCI-N87 cells stably transfected with pEGFPNl-DNEGFR (DN group). The cell cycle was determined by flow cytometry. The protein levels of cyclin-de-pendent kinase 2 (CDK2) , cyclin Dl, phosphorylated glycogen synthase kinase 3 beta at Ser9 [p-GSK-3β (Ser9) ], p21 and p27 were detected by Western blotting. RESULTS: Transfection of the human gastric cancer cells with pEGFPN1-DNEGFR led to G0/G1, arrest, and down-regulated CDK2, cyclin Dl, p-GSK-3β (Ser9) and up-regulated p21 and p27 as well. CONCLUSION: DNEGFR down-regulates cyclin Dl by activating GSK-3β, down-regulates CDK2, and up-regu-lates p21 and p27, which induce G0/G1 arrest in human gastric cancer cells in the end.%目的:探讨人表皮生长因子受体显性负性突变体(dominant negative epidermal growth factor receptor,DNEGFR)对胃癌细胞细胞周期的影响及其分子机制.方法:选用2株人胃癌细胞,分为如下6组:SGC-7901细胞未转染组(US组)、SGC-7901细胞pEGFP-N1质粒转染组(ES组)、SGC-7901细胞pEGFPNl-DNEGFR质粒转染组(DS组)、NCI-N87细胞未转染组(UN组)、NCI-N87细胞pEGFP-N1质粒转染组(EN组)和NCI-N87细胞pEGF-PNl-DNEGFR质粒转染组(DN组).采用流式细胞术检测细胞周期,Western blotting检测细胞周期素依赖性蛋白激酶2(CDK2)、cyclin D1、Ser9位点磷酸化糖原合成酶激酶3β[p-GSK-3β(Ser9)]、p21和p27蛋白水平.结果:转染pEGFPNl-DNEGFR质粒的人胃癌细胞株出现Go/G1期阻滞,CDK2、cyclin D1和p-GSK-3β(Ser9)蛋白水平降低,p21和p27蛋白水平则升高.结论:DNEGFR通过激活GSK-3β使cyclin D1蛋白水平降低,并降低CDK2蛋白水平,上调p21和p27蛋白水平,最终导致胃癌细胞发生G0/G1期阻滞.这一结果将为胃癌生物治疗研究提供新思路.