上调microRNA-34a抑制胶质瘤细胞的增殖及侵袭

目的 探讨microRNA-34a(miR-34a)在胶质瘤组织中的表达情况以及对人脑胶质瘤细胞系U251增殖及侵袭的影响.方法 选取川北医学院附属医院2013年3月至2017年3月胶质瘤组织标本30例和重症脑外伤需行手术者正常脑组织标本10例作为研究对象,采用荧光定量PCR法检测miR-34a在胶质瘤组织表达情况.体外实验,将人工合成的miR-34a模拟物miR-34a mimic转染至U251细胞系,采用荧光定量PCR、MMT、Transwell法检测miR-34a在U251细胞系中表达以及对U251细胞增殖和侵袭能力的影响.依据细胞转染情况,分为Control组(不转染任何基因)、Mock组(转染miRNA-neg序列)和miRNA-34 a mimic组(转染miRNA-34a mimic序列).结果 miRNA-34a在人脑胶质瘤组织中相对表达水平为(0.35±0.07),低于正常人脑组织的(1.00±0.13),差异有统计学意义(P<0.05);转染后,荧光定量PCR结果显示,Control组、Mock组、miRNA-34a mimic组miRNA-34a相对表达水平分别为(1.00±0.08)、(0.98±0.11)和(6.19±0.34),miRNA-34a mimic组与Control、Mock组比较,差异有统计学意义(P<0.05);MMT结果显示,在不同时间点,miRNA-34a mimic组U251细胞增殖抑制率高于Control组、Mock组,差异有统计学意义(P<0.05);Transwell结果显示,Control组、Mock组、miRNA-34a mimic组侵袭细胞数分别为(90.53±5.84)个、(88.21±5.04)个和(27.46±2.76)个,miRNA-34a mimic组与Control、Mock组比较,差异有统计学意义(P<0.05).结论miR-34a在胶质瘤组织中表达下调,上调miR-34a表达可抑制胶质瘤细胞的增殖及侵袭.

Effect of up-regulation of microRNA-34a on proliferation and invasion of glioma cells

Objective To investigate the expression of microRNA -34a (miR-34a) in glioma and its effect on the proliferation and invasion of human glioma cell line U251.Methods 30 cases of glioma tissue samples and 10 cases of normal brain tissue samples of patients with severe traumatic brain injury were selected as the subjects during March 2013 to March 2017.The expression of miR -34a in gliomas was detected by fluorescence quantitative PCR .In in vitro experiments, the synthetic analogue miRNA -34a mimic of miRNA -34a was transfected into U251 cell lines.The expression of miRNA-34a in U251 cell lines was detected by fluorescence quantitative PCR , MMT and Transwell method and its effect on proliferation and invasion of U 251 cell lines was analyzed .According to cell transfection , the patients were divided into control group (without transfection of any gene), mock group (transfection with miRNA -neg sequence) and miRNA-34a mimic group (transfection with miRNA-34a mimic sequence).Results The expression level of miRNA -34a in human glioma tissues was significantly lower than that in normal brain tissues (0.35 ±0.07) vs(1.00 ±0.13)] (P<0.05).Quantitative fluorescence PCR showed that the expression levels of miRNA -34a were (1.00 ±0.08), (0.98 ±0.11) and (6.19 ±0.34), respectively in control group and mock group and the miRNA -34a group after transfection, and there were statistical differences among the three groups (P<0.05).The results of MTT showed that the proliferation inhibition rate of U 251 cells in miRNA-34a group was significantly higher than that in control group and mock group at different time points (P<0.05).The results of Transwell experiment showed that the invasion cell amount of U 251 cells was (90.53 ±5.8), (88.21 ±5.04) and (27.46 ±2.76), respectively in control group and mock group and miRNA -34a group, and there were statistical differences among the three groups (P<0.05).Conclusion The expression of miRNA-34a is low while the expression of miRNA-34 a is high in glioma , which can inhibit the proliferation and invasion of glioma cells .