中文摘要：

目的 观察miR-29对胃癌细胞体外侵袭力的影响，探讨miR-29通过ITGB1调节胃癌侵袭和转移的具体机制。方法 通过基因芯片筛选胃癌与癌旁组织中差异性表达的miRNA；采用生物信息学预测ITGB1调控相关miRNA，通过比对上述2个结果，筛选出miR-29；进一步以miR-29 慢病毒及miR-29 mimics过表达miR-29后，用Western blot检测胃癌细胞中ITGB1的表达变化；采用双荧光素酶实验分析miR-29与ITGB1的作用机制；采用 Transwell侵袭实验及划痕实验检测miR-29 慢病毒感染后细胞体外侵袭能力的变化；qRT-PCR 检测60例胃癌患者癌组织和癌旁组织中 miR-29 的表达差异，并分析 miR-29的表达与肝癌患者临床病理之间的关系。 结果 基因芯片及生物信息学预测发现miR-29在胃癌组织里高表达，同时又可能调控ITGB1；双荧光素酶实验证实miR-29可以结合在ITGB1 3′UTR， miR-29 慢病毒及miR-29 mimics过表达miR-29都能在蛋白水平下调ITGB1；qRT-PCR 结果显示miR-29家族3条miRNA在胃癌组织中的相对含量均低于癌旁组织[miR-29a：癌旁（32.01±10.38），癌（14.16±6.25）；miR-29b：癌旁（26.95±5.05），癌（9.82±1.86）；miR-29c：癌旁（53.56±8.05），癌（16.79±1.97），P〈0.01]；进一步统计学分析表明，miR-29a与淋巴结转移有关（P〈0.05），miR-29b在具有远处转移的病例组织中C/P比值较无远处转移的病例组织明显降低（P〈0.05）。 结论 miR-29可以在转录后水平调控ITGB1的表达，从而抑制胃癌细胞的侵袭和转移。

英文摘要：

Objective To investigate the underlying molecular mechanisms of miR-29 regulating ITGB1 in the invasion and migration of gastric adenocarcinoma. Methods MicroRNA array was used to screen out miRNAs which were expressed with significant differences in gastric cancer and paracancer tissue. Bioinformatics was employed to predict the miRNAs related to ITGB1 regulation. Gastric cancer cells were infected by lentiviral vectors or transfected with miR-29 mimics to over-express miR-29. Western blotting was used to detect the changes of ITGB1 in gastric cancer cells. Dual luciferase assay was adopted to analyze the mechanism of miR-29 regulating ITGB1. Transwell invasion assay was accomplished to analyze cell invasion ability. The quantitative real-time polymerase chain reaction （qRT-PCR） was adopted to detect the expression differences of miR-29 in 60 pairs of gastric cancer tissue and adjacent noncancerous tissues. The relationship between the expression and clinical pathological data was analyzed. Results MicroRNA array and bioinformatics prediction results supported that miR-29 was in a low expression in gastric carcinoma, and regulated ITGB1. Dual luciferase assay confirmed that miR-29 was bond to the 3′UTR of ITGB1. Western blotting suggestedthat ITGB1 was down-regulated as miR-29 over-expression. The results of qRT-PCR suggested that the relative expression of miR-29 in gastric cancer tissues was lower than in the adjacent noncancerous tissues （miR-29a： 14.16±6.25vs 32.01±10.38; miR-29b： 9.82±1.86vs 26.95±5.05; miR-29c： 16.79±1.97 vs 53.56±8.05, P〈0.01）. Statistical analysis showed that the expression of miR-29a was closely related with lymph node metastasis （P〈0.05）. The expression ratio of miR-29b in gastric cancer tissues to adjacent noncancerous tissues was significantly lower in the tissue with distant metastasis （P〈0.05）. Conclusion miR-29 regulates ITGB1 expression at post-transcriptional level, and then suppresses the invasion and metastasis of gastric adenocarcino