BUB1表达对结直肠癌细胞增殖、凋亡及PLK1/PTEN信号通路的影响

Effects of BUB1 expression on the proliferation,apoptosis and PLK1/PTEN signal pathway of colorectal cancer cells

目的探讨苯并咪唑出芽抑制解除同源物蛋白1(BUB1)表达对结直肠癌细胞增殖、凋亡及Polo样激酶1(PLK1)/10号染色体上缺失的磷酸酶及张力蛋白同源基因(PTEN)信号通路的影响,以期为结直肠癌的临床治疗提供理论依据。方法以2018年8月至2020年8月在该院收集的125对结直肠癌患者癌组织及邻近癌旁组织,以及人结直肠癌细胞系SW1116、SW480、HCT116、HT-29与人正常结肠黏膜上皮细胞NCM460为研究对象;利用Lipofectamine^(TM)2000转染试剂盒对SW480细胞进行转染,并分组为空白组(细胞未转染)、si-NC组(细胞转染si-NC)、si-BUB1-1组(细胞转染si-BUB1)、si-BUB1-2组(细胞转染si-BUB1-2)。Western blot检测各组细胞中BUB1、促凋亡蛋白Bax、抗凋亡蛋白Bcl-2及PLK1/PTEN信号通路相关蛋白表达;CCK-8法检测各组细胞在0、24、48、72 h的增殖情况;流式细胞术检测各组细胞凋亡情况。结果BUB1在结直肠癌组织的表达水平显著高于癌旁组织(P<0.05);与人正常结肠黏膜上皮细胞NCM460比较,人结直肠癌细胞SW1116、SW480、HCT116、HT-29中BUB1表达水平均显著升高(P<0.05),且BUB1表达水平在SW480细胞中最高,因此,选择SW480细胞进行后续研究;与空白组和si-NC组比较,si-BUB1-1组、si-BUB1-2组SW480细胞中细胞凋亡率、Bax及PTEN蛋白表达水平显著升高,细胞增殖能力及BUB1、Bcl-2、PLK1表达水平显著降低(P<0.05),空白组与si-NC组比较差异无统计学意义(P>0.05)。结论抑制BUB1表达可抑制癌细胞增殖,促进细胞凋亡,该机制可能与PLK1/PTEN信号通路中PLK1表达水平下调,PTEN蛋白表达水平上调有关。

Objective To investigate the effects of budding uninhibited by benzimidazoles 1(BUB1)expression on the proliferation and apoptosis of colorectal cancer cells and Polo-like kinase 1(PLK1)/phosphatase and tensin homolog deleted on chromosome ten(PTEN)signaling pathway,in order to provide a theoretical basis for the clinical treatment of colorectal cancer.Methods A total of 125 pairs of cancer tissues and adjacent tissues of colorectal cancer patients collected in the hospital from August 2018 to August 2020,as well as human colorectal cancer cell lines SW1116,SW480,HCT116,HT-29 and human normal colonic mucosal epithelial cells NCM460 were used as the research objects.SW480 cells were transfected with LipofectamineTM2000 transfection kit and divided into the blank group(cells without transfection),the si-NC group(cells transfected with si-NC),the si-BUB1-1 group(cells transfected with si-BUB1-1),and the si-BUB1-2 group(cells transfected with si-BUB1-2).Western blot was used to detect the expression of BUB1 protein,pro-apoptotic protein Bax,anti-apoptotic protein Bcl-2 and PLK1/PTEN signaling pathway related proteins in each group of cells;CCK-8 method was used to detect the proliferation of cells in each group at 0,24th,48th,72th hours;flow cytometry was used to detect cell apoptosis in each group.Results The expression level of BUB1 protein in colorectal cancer tissues was significantly higher than that in adjacent tissues(P<0.05).Compared with human normal colonic mucosal epithelial cells NCM460,the expression level of BUB1 protein in human colorectal cancer cells SW1116,SW480,HCT116 and HT-29 were significantly increased(P<0.05),and the expression level of BUB1 protein was the highest levels in SW480 cells.Therefore,SW480 cells were selected for follow-up research.Compared with the blank group and the si-NC group,the apoptosis rate,Bax and PTEN protein expression in SW480 cells in the si-BUB1-1 group and si-BUB1-2 group were significantly increased;but the cell proliferation ability,BUB1,Bcl-2 and PLK1 protein expression levels were significantly reduced(P<0.05),there was no significant difference between the blank group and the si-NC group(P>0.05).Conclusion Inhibition of BUB1 expression can inhibit cancer cell proliferation and promote cell apoptosis.This mechanism may be related to the down-regulation of PLK1 protein expression and the up-regulation of PTEN protein expression in the PLK1/PTEN signaling pathway.