MicroRNA-100对肝癌细胞增殖活力和细胞周期的影响

Effect of microRNA-100 on proliferation activity and cell cycle of hepatocarcinoma cells

目的:探讨microRNA-100(miR-100)对肝癌细胞增殖活力和细胞周期的影响及其可能机制。方法:通过脂质体介导将人工合成的miR-100模拟物及其阴性对照转染人肝癌HepG2细胞,用细胞计数试剂盒8(CCK-8)方法检测转染后HepG2细胞的增殖活力,用流式细胞术判定细胞周期分布,并进一步用实时荧光定量RT-PCR和Western blotting分析Polo样激酶1(Plk1)的表达水平。结果:荧光显微镜下观察到经阳离子脂质体介导的细胞转染效率大于85%。转染miR-100模拟物的实验组细胞的增殖抑制率在24、48和72 h分别为(43.5±12.2)%、(46.5±3.7)%和(52.1±0.2)%,均显著高于对照组细胞(P<0.01),并且在72 h实验组细胞增殖指数(35.8±1.4)低于阴性对照组(39.2±1.0)和单纯脂质体组(40.7±2.0)(P<0.05)。同时与对照组相比,实验组细胞Plk1 mRNA和蛋白表达水平在转染miR-100后72 h明显降低(P<0.05)。结论:miR-100可抑制肝癌细胞增殖,其机制可能与其下调Plk1的表达有关。

AIM： To investigate the effect of microRNA-100 （miR-100） on the proliferation activity and cell cycle of hepatocarcinoma cells. METHODS ： Synthetic miR-100 mimic and its negative control were transfected into hu- man hepatocarcinoma HepG2 cells by liposome method. After transfection, the cell counting kit-8 （CCK-8） was used to measure the cell proliferation activity. The cell cycle distribution was determined by flow cytometry. The expression of Polo- like kinase 1 （Plkl） at mRNA and protein levels was detected by quantitative real-time PCR （qRT-PCR） and Western blotting. RESULTS： The transfection efficiency mediated by cationic liposome was greater than 85%. The inhibitory rates of cell proliferation in HepG2 cells were （43.5 ± 12.2） %, （46.5 ± 3.7 ） % and （52.1 ± 0.2） % at 24 h, 48 h and 72 h after transfected with miR-100 mimic, respectively, which were significantly increased as compared with the control cells. Moreover, the cell proliferation index in experimental group （35.8 ± 1.4） was higher than that in negative control group （39.2 ± 1.0） and simple liposome group （40.7 ± 2.0） at 72 h. At the same time, the mRNA and protein expression levels of Plkl obviously decreased in HepG2 cells transfected with miR-100 at 72 h after transfection. CONCLUSION： miR-100 suppresses the proliferation activity of hepatocarcinoma cells by down-regulating Plkl gene expression.