miR-20b促进胃癌细胞增殖研究

miR-20b promotes cell growth in gastric cancer

目的：探讨miR-20b对胃癌细胞生长影响及其可能的机制。方法 miR-20b mimic和其特异的抑制剂分别转染胃癌MGC803细胞，二甲基四氮唑蓝（MTT）和流式细胞术检测miR-20b mimic和其特异抑制剂在细胞生长和细胞周期上的效应，western blot检测细胞周期因子的表达改变。结果在转染miR-20b后，胃癌细胞生长加快，而细胞周期则加快由G1向S期转换。而在转染miR-20 b抑制剂后，细胞生长能力明显降低，且细胞周期也出现G1/S转换障碍。机制分析显示，在抑制miR-20b表达后，细胞增殖相关因子c-Myc和细胞周期蛋白D1（ Cyclin D1，CCND1）表达减低，而抑癌因子p21和p15表达显著提高。结论 miR-20b作为oncomiRNA，其通过调节细胞周期相关因子的表达影响胃癌细胞增殖。

Objective To investigate the effect of miR-20b on cell proliferation and cell cycle in gastric cancer because of up-regulation of miR-20b in gastric cancer.Methods miR-20b mimics and its inhibitor were respectively transfected into MGC 803 gas-tric cancer cell and methyl thiazolyl tetrazolium （ MTT ） and fluorescence-activated cell sorting （ FACS ） were used to analyze cell growth and cell cycle.Western blot was used to explore the molecular basis of miR-20b.Results Compared with its control, cell growth was obvious elevated and the cell cycle transition was also increased from G 1 to S phase after miR-20b mimics transfection .After transfecting miR-20b inhibitor, cell growth was markedly decreased and cell cycle transition was also delayed from G 1 to S phase.Fur-thermore, miR-20b induced the expression of cyclin D1 （CCND1） and C-Myc, decreased the expressions of p21 and p15.Conclu-sions miR-20b was considered as a potential oncogene to modulate cell growth and cell cycle transition through regulating the expres -sion of cell cycle-related genes .