siRNA沉默DNA聚合酶β基因对胃癌BGC-823细胞增殖的影响  

Effect of silencing DNA polymerase β by siRNA on proliferation of human gastric cancer cell line BGC-823

作　　者：王蕾[1] 董子明[1] 赵国强[2] 

机构地区：[1]郑州大学基础医学院病理生理学教研室,郑州450001 [2]郑州大学基础医学院微生物与免疫学教研室,郑州450001

出　　处：《肿瘤》2008年第8期651-655,共5页Tumor

基　　金：国家自然科学基金资助项目(编号:30471952)

摘　　要：目的:观察siRNA沉默DNA聚合酶β(DNA polymerase β,polβ)基因后对胃癌BGC-823细胞增殖的影响。方法:用实时荧光定量PCR(real-time fluorogentic quantitative PCR,RFQ-PCR)和Western印迹法检测先前构建好的转染不同siRNA载体的各组细胞中polβ mRNA和蛋白质表达水平,用FCM法和裸鼠体内成瘤实验检测各组细胞的增殖情况。结果:转染polβ靶向siRNA的BGC-823细胞中polβ mRNA和蛋白质表达水平均明显降低,且siRNA载体pRNAT-U6.1-sipolβ2(抑制程度83%)的沉默抑制作用强于siRNA载体pRNAT-U6.1-sipolβ1(抑制程度56%);与无关siRNA对照组、空载体对照组和空白对照组相比,转染pRNAT-U6.1-sipolβ1组细胞的S期比例及细胞增殖速度明显下降,而转染pRNAT-U6.1-sipolβ2组细胞的S期比例以及细胞增殖则明显升高,差异均有统计学意义(P<0.05)。结论:DNA polβ高表达和近乎完全抑制的超低水平表达都不利于维持细胞的生理状态;BGC-823细胞中polβ表达通过siRNA沉默到合适的低水平,对肿瘤的生长可以起到抑制作用。Objective ： To investigate the effects of silencing DNA polymerase β by small interfering RNA （siRNA） on the proli- feration of human gastric cancer cell line BGC-823. Methods： Various siRNA expression vectors were constructed and transfeeted into BGC-823 cells. The expression levels of pol β mRNA and protein were detected by real-time PCR and Western blotting, respectively. The proliferation of BGC-823 cells was detected by flow eytometry in vitro and evaluated by tumor formation test in nude mice. Results： The expression levels of polβ mRNA and protein were obviously reduced in experimental group transfeeted with pol β-targeted siRNA expression vectors, and the silencing degree of pRNAT-U6.1-sipolβ2 vector was stronger than that of pRNAT-U6.1-sipolβ1 vector （83% vs 56% ）. Compared with irrelevant siRNA control group, empty vector control group, and un-transfeeted group, the proportion of cells in S phase and cell proliferation speed significantly decreased in pRNAT-U6.1-sipolβ1 transfeetion group （P 〈 0.05） ; on the contrary, the proportion of cells in S phase and cell proliferation speed significantly increased in pRNAT-U6.1 -sipolβ2 transfeetion group （ P 〈 0.05）. Conclusion：Over-expression or nearly complete inhibition of expression of polβ has no benefit to maintain the cells＇normal physiological functions. The tumor growth could be inhibited by silencing the expression of pol β by siRNA to appropriate low level.

关 键 词：胃肿瘤 DNA聚合酶Β RNA 小分子干扰 细胞增殖 

分 类 号：R734.2[医药卫生—肿瘤]