变异IκBα抑制肝癌细胞株SMMC-7721中NF-κB活性及细胞生长

Nuclear factor kappa B activity and cell viability of SMMC-7721 inhibited by mutated inhibitor kappa B alpha

目的 了解变异IκBα(mIκBα)转染到肝癌细胞株SMMC-7721细胞中是否抑制NF-κB向核内转位活性及细胞的生长。 方法 电泳迁移率分析检测32p标记的寡核苷酸探针与NF-κB结合情况,westernblot检测核内NF-κB表达情况,细胞生长曲线分析和细胞增殖实验分析肝癌细胞生长情况。 结果 转染mIκBα质粒肝癌细胞在0、24、48、96 h未见核内蛋白与κ B探针结合转染,而转染对照PcDNA3质粒肝癌细胞始终可见核内蛋白与κB探针强结合;Western blot结果也显示0、24、48、96 h未见核内NF-κB表达,而对照PcDNA3质粒核内NF-κB高水平表达。细胞增殖实验分析发现转染mIκBα质粒肝癌细胞生长受到抑制,而转染对照PcDNA3质粒肝癌细胞生长未受影响,第2天开始转染mIκBα质粒肝癌细胞与其它两种细胞比较差异有非常显著性,增殖效率值分别是5 092.63±541.41、7 851.87±72.76、8 240.88±603.26,t值分别是14.29、10.99,P<0.01。 结论 转染mIκBα质粒肝癌细胞可以持续表达mIκBα,抑制NF-κB向核内转位,从而抑制肿瘤细胞的生长。

Objective To investigate the inhibition consequence of NF-κB activity and cell viability by transfecting mutated inhibitor kappa B alpha (mI κB α) into liver cancer cell line of SMMC-7721 cells. Methods The nucleic proteins of SMMC-7721 cells transfected with mIκBα plasmid and cells with empty pcDNA3 vector were used to determine not only the binding of the 32P-labelled κB probes by EMSA , but also the expression of NF-κB by western blot. Cell viability was also analyzed. Results NF- KB nuclear translocation was inhibited remarkably in SMMC-7721 cells transfected with ml KB a at 0, 24, 48 and 96 hours. Furthermore, NF-κB was not detected in the nucleic protein of mIκBα -transfected cells at the same intended time by western blot. Compared with that of control cells, the growth of SMMC-7721 cells transfected with ml κBα was suppressed evidently, especially on the second day, the cpm values of ml κBα -transfected cells, pcDNA3-transfected cells, and control cells were 5 092.63± 541.41, 7 851.87 ± 72.76, and 8 240.88 ± 603.26 respectively (t = 14.29, P<0.01; t= 10.99,P<0.01). Conclusion Stable expression of mIκBα in SMMC-7721 cells transfected with mI κBαplasmid inhibits NF- KB nuclear translocation, then suppresses the cell growth.