中文摘要：

[目的]检测微小RNA（miR）451-在胃癌组织中的表达,分析其在不同病理因素患者中表达水平。通过转染miR-451的模拟物和抑制物,观察其对胃癌细胞周期的影响。[方法]收集了56例胃癌患者的癌症组织和癌旁组织,采用实时荧光定量PCR法检测miR-451的相对表达量,并分析不同病理因素患者miR-451的表达量;选择高分化MKN-28、低分化BGC-823胃癌细胞株分别通过靶向miR-451模拟物和靶向miR-451抑制物转染细胞,检测细胞周期的变化。[结果]与癌旁组织相比,胃癌组织miR-451的表达量下调（P〈0.05）。胃癌组织的分化程度和Lauren分型与miR-451的表达量相关（P〈0.05）。在两种不同分化类型胃癌细胞株中,转染miR-451模拟物的细胞G0/G1期比例高于对照组细胞该期比例（P〈0.05）,转染miR-451抑制物的细胞G0/G1期比例低于对照组细胞该期比例（P〈0.05）。[结论]miR-451的表达下调可能与胃癌发生发展有关,低表达miR-451可促进细胞分裂,加快胃癌细胞周期进程,高表达miR-451可阻滞细胞周期进程,使其停滞于G0/G1期。miR-451表达与分化程度及Lauren分型情况相关。

英文摘要：

[ Objective ] To detect the expression of microRNA-451 （miR-451） in gastric cancer tissues, explore its relationship with clinicopathologic characteristics, and observe the effect on gastric cancer cell cycle by transfecting miR-451 mimics and inhibitors in gastric cancer ceils. [ Methods ] Cancer tissues and para-carcinoma tissues were collected from 56 volunteers with gastric carcinoma. Real-time fluorescent quantitative PCR technology was used to test the relative expression level of miR451 and analyze its level with selected clinicopathologic factors. Additionally, the highly differentiated MKN-28 and poorly differentiated BGC-823 gastric cancer cell lines transfected with targeted miRNA-451 mimics and targeted miRNA-451 inhibitors were used to detect the effects on cell cycle. [ Results ] Compared with the para-carcinoma tissues, the miR-451 expression level in gastric cancer tissues was declined significantly （P 〈 0.05）. The miR-451 expression level was correlated with differentiation degree and Lauren classification （P 〈 0.05）. The in vitro study showed that the G0/G1 phase ratio of cells transfecting with miR-451 mimics was significantly higher than that in the control group （P 〈 0.05）, while the ratio of cells transfecting with miR-451 inhibitors was significantly lower （P〈0.05）. [ Conclusion ] Declining miR-451 expression may be related to the occurrence and development of gastric cancer. Low miR-451 expression could enhance cell division and accelerate gastric cell cycle process, but the high miR-451 expression would arrest cell cycle into GO/G1 phase. MiR-451 expression might be related to the differentiation degree and Lauren classification.