中文摘要：

目的选取4种在胃癌组织中异常表达的miRNAs,探讨它们在不同亚型胃癌组织中的表达差异。方法采用Real-time PCR检测29例肠型胃癌与21例弥漫型胃癌组织及其相应正常胃黏膜组织中miR-27a、miR-494、miR-145和miR-886-3p的表达水平。结果 miR-27a在弥漫型胃癌组织中的表达水平增加2.87倍,在肠型胃癌组织中增加4.64倍,均为高水平表达（P〈0.01）,与弥漫型胃癌相比,在肠型胃癌组织中miR-27a的表达更高,差异具有统计学意义（P〈0.01）。miR-494在弥漫型胃癌组织中的表达下降了4.39倍,在肠型胃癌组织中则只下降了2.50倍,两者之间差异也有统计学意义（P〈0.01）。miR-145在肠型胃癌组织中下调3.28倍（P〈0.01）,在弥漫型胃癌组织中只下调2.02倍（P〈0.01）。miR-886-3p在肠型胃癌组织中异常高表达,且与弥漫型胃癌组织中表达水平相似。结论在不同亚型胃癌组织中miRNA表达水平与表达模式存在显著性差异,可能导致胃癌亚型间基因表达水平的不同。

英文摘要：

【Objective】 To investigate the different expression patterns of miRNAs between intestinal-type and diffuse-type gastric cancer.【Methods】 Four aberrantly expressed miRNAs in gastric cancer were selected.Their expressions in both cancer and normal tissues were detected in 29 intestinal-type gastric cancer patients and 21 diffuse-type gastric cancer patients by real-time PCR.【Results】 Compared with that in normal tissues,miR-27a expression in tumor tissues increased 2.87 fold in diffuse-type gastric cancer and 4.64 fold in intestinal-type gastric cancer.Although miR-494 expression decreased in both intestinal-type and diffuse-type gastric cancer with p values less than 0.01,it decreased 4.39 fold in diffuse-type gastric cancer and only 2.50 fold in intestinal-type cancer,which was significant different（P〈0.01）.MiR-145 expression decreased 3.28 fold in intestinal-type gastric cancer and only 2.02 fold in diffuse-type gastric cancer,which was also obviously different（P〈0.01）.MiR-886-3p expression levels were similar in the two subtypes of gastric cancer（P〈0.05）.【Conclusions】 Expression levels of 4 miRNAs are different in the two subtypes of gastric cancer,which may result in different expressions of target genes.