中文摘要：

目的观察miR-451对人脑胶质瘤细胞系U251迁移运动能力的影响，探讨miR-451影响U251细胞运动的潜在机制。方法qRT．PCR检测人脑胶质母细胞瘤组织标本及正常脑组织标本miR-451相对表达量。利用U251细胞系进行miR-451对人脑恶性胶质瘤细胞迁移运动能力影响的体外实验研究，实验分为转染miR-451抑制物组（miR-451inhibitor）和空白对照组（N．C．）。运用脂质体Lipofetmiane2000将miR-451抑制物序列（5’-AACUCAGUAAUGGUAACGGUUU-3’）转染进入U251细胞中，同时设立空白对照组。应用Transwell细胞迁移实验和细胞划痕实验观察各组细胞迁移运动能力的强弱，明确miR-451对U251细胞迁移能力的影响。Westernblot检测各组细胞GTP—Racl及Racl蛋白水平，从其表达水平与miR-451相对表达量的相互关系探讨miR-451影响U251细胞迁移运动能力的可能机制。结果qRT—PCR检测显示胶质母细胞瘤组织标本中miR-451的相对表达量较对照脑组织标本降低（P〈0．01）。Transwell细胞迁移实验和细胞划痕实验发现转染miR-451抑制物组U251细胞迁移运动能力较对照组显著提高（P〈0．01）。Westemblot检测表明转染miR-451抑制物组U251细胞中GTP-Racl含量较对照组升高（P〈0．01）而Racl蛋白水平没有差异（P〉0．05）。结论miR-451可通过抑制13251细胞中Racl的激活限制细胞迁移运动能力。

英文摘要：

Objective To investigate the effect of microRNA-451 （miR-451） on migration and its potential molecular mechanism in glioma cell line U251. Method The expression of miR-451 in glioma tissues and brain tissues was identified by qRT-PCR. U251 cells were divided into two groups, miR-451 inhibitor group and control group, for in vitro experiments. Oligonucleotide of miR-451 inhibitor was transfected into human glionblastoma cell line U251. The migration of each group cells was examined by Wound Healing assay and Transwell assay, and the expression of protein of GTP-Racl and Racl were determined by Western blot respectively. Results The levels of miR-451 expression in glioma tissues were significant lower than brain tissues （ P 〈 0. 01 ）. Wound Healing assay and Transwell assay discovered that the migration of miR-451 inhibitor group cells was obviously increased compared with control group（ P 〈 0. 01）. Western blot demonstrated that the expression of GTP-Racl was up-regulated in miR-451 inhibitor group cells（ P 〈0. 01 ） and no significantly different was found in the expression of Raclof each group （ P 〉 0. 05 ）. Conclusions miR-451 inhibits U251 cells migration through reducing activation of Racl.