【摘要】 目的探讨靶向羧肽酶B2(CPB2)基因的小干扰RNA(siRNA)对乳腺癌MDA-MB-231细胞凝血酶激活的纤溶抑制物(TAFI)表达以及对乳腺癌细胞的生长和转移的影响。方法将细胞分为siRNA-1组、siRNA-2组、siRNA-3组、阴性对照组和空白对照组5组,设计并化学合成编码TAFI基因(CPB2)的特异性siRNA,用脂质体2000转染至MDA-MB-231细胞中,采用Western blot、RT-PCR分别检测各组TAFI蛋白及mRNA的表达,Transwell侵袭实验检测癌细胞转移侵袭能力,四甲基偶氮唑蓝(MTT)法测定细胞存活和生长情况。结果 siRNA抑制CPB2表达后,TAFI蛋白及其mRNA表达水平显著下降,siRNA-1组、siRNA-2组、siRNA-3组与阴性对照组比较细胞侵袭力和细胞生长都明显受到抑制(P<0.05)。结论靶向CPB2的siRNA可有效下调乳腺癌细胞MDA-MB-231中TAFI蛋白及其mRNA表达水平,降低肿瘤细胞的侵袭力,抑制细胞的生长和转移。更多还原

【Abstract】 Objective To investigate effects of carboxypeptidase B2(CPB2) gene silencing on expression of thrombin activated fibrinolysis inhibitor(TAFI) and growth and metastasis of the breast cancer cell line MDA-MB-231.Methods Cells were divided into five groups: the siRNA-1 group,the siRNA-2 group,the siRNA-3 group,the negative control group and the blank control group.Based on the sequence of CPB2,three siRNAs were designed and chemically synthesized,and then transfected into the breast cancer cell line MDA-MB-231 with lipofectamine 2000.TAFI mRNA and protein levels were determined by reverse transcription-polymerase chain reaction(RT-PCR) and Western blot.Cell invasive and metastasis abilities and growth inhibition were determined by Transwell assay and MTT assay.Results siRNAs targeting CPB2 significantly down-regulated mRNA and protein levels of TAFI(P<0.05),and the inhibition ratio ranged from 55.4% to 42.6%.The growth of the breast cancer cell line MDA-MB-231 was inhibited in siRNA groups(P<0.05),and invasive and metastasis abilities were also significantly inhibited compared with the negative control group(P<0.05).Conclusion CPB2-siRNA can significantly down-regulate expression of TAFI in transcriptional and translational levels,and inhibits cell growth,invasion and metastasis ability of the breast cancer cell line MDA-MB-231.更多还原