中文摘要：

目的研究miRNA-10a在胃癌中的表达及其在胃癌中的功能，探讨其启动子区的高甲基化与胃癌发生的相关性。方法使用Taqman探针对35对胃癌组织标本进行实时定量PCR检测，统计学分析miRNA-10a的表达情况与临床病理因素的相关性，随后使用甲基化特异性PCR（MSP）检测样本中miRNA-10a上游启动子区的甲基化情况。并通过细胞增殖实验研究miRNA-10a在胃癌细胞系中的功能。结果在35对胃癌样本中，其中．24例miRNA-10a的表达水平下调。11例表达水平上调。与临床病理因素的相关性分析显示，miRNA-10a在胃癌组织中的低表达，与胃癌的TNM分期呈负相关（P〈0．05）。MSP结果显示，癌组织的甲基化水平明显高于相对应的癌旁组织，差异有统计学意义（P〈0．05）。细胞增殖实验显示，过表达miRNA-10a后能够明显抑制胃癌细胞的增殖速度。结论胃癌组织中miRNA-10a的表达呈现普遍的低表达趋势，且miRNA-10a的低表达与胃癌的TNM分期呈负相关，其启动子区的高甲基化可能是导致miRNA-10a表达下调，参与胃癌发生的原因之一，并且miRNA-10a可能在胃癌的发生中起肿瘤抑制基因的作用。

英文摘要：

Objective To investigate the expression of miRNA-10a and its function in gastric cancer （GC） and also its genomic promoter DNA methylation. Methods Detected the expression of miRNA-10a in 35 GC patients by real-time i？CR using Taqrnan probes.The association between miRNA-10a expression and clinicopathological factors was ana- lyzed by SPSS 19.0.DNA methylation status was detected by methylation-specific PCR （MSP）.The function of miRNA- i0a on cell proliferation was detected by CCK-8 kit. Results Out of 35 GC patients,the expression of miRNA-10a was down-regulated in 24 cases compared with the adjacent tissues.The low expression of miRNA-10a was signifi- cantly associated with gastric cancer TNM stage （P 〈 0.05）.The methylation level in GC tissues was higher than in the matched adjacent non-neoplastic tissues （P 〈 0.05）.Overexpression of miRNA-10a reduced the cell proliferation of GC cell lines. Conclusion miRNA-10a is down-regulated in majority of GC tissues possibly because of the high methyla- tion level of its promoter in GC tissues.The inhibition of miRNA-10a on cell proliferation suggested that it acted as a tumor suppressor in gastric cancer.