中文摘要：

目的探讨肺癌A549细胞上皮-间质转化（EMT）对微小RNA（miRNA）表达的影响。方法采用不同浓度的转化生长因子B1（TGF-131）诱导肺癌A549细胞发生EMT，应用相差显微镜观察A549细胞形态学变化，采用Westernblot法检测EMT相关标记蛋白表达的变化，应用miRNA芯片检测EMT前后miRNA表达的变化，应用荧光定量逆转录聚合酶链反应（RT—PCT）验证芯片结果的可靠性。结果肺癌A549细胞发生EMT后，细胞形态拉长，细胞间连接变得疏松。肺癌3．549细胞发生EMT后，上皮标记蛋白E-钙黏附素（E-cadherin）表达降低，而间质标记波形蛋白（Vimentin）和纤维连接蛋白（Fibronectin）表达上调。miRNA芯片获得51个miRNA在诱导前后有统计学意义（P〈0．05），且表达差异在2倍以上。18个表达上调，33个表达下调，其中mir-33a和mir-193a-3p的表达经诱导后分别下调了92．8％和86．5％；荧光定量RT-PCR检测mir-33a和mir-193a-3p的表达经诱导后分别下调了73．1％和56．6％。结论EMT可影响肺癌A549细胞中miRNA的表达变化，miRNA可能通过EMT调节肺癌侵袭转移。

英文摘要：

Objective To investigate the effect of epithelial-mesenchymal transition （EMT） on the expression of microRNAs （miRNAs） in lung cancer A549 cells. Methods Transforming growth factor beta- 1 （TGF-IM） in different concentrations was used to induce EMT in lung cancer A549 cells. The morphological changes were observed under phase-contrast microscope. The changes of EMT-related proteins were analyzed by Western blot. The changes of miRNAs expression after EMT were detected by microRNA （miRNA） array. Real time quantitative RT-PCR was applied to verify the reliability of miRNA array results. Results The lung cancer A549 cells became elongated and the cell-cell junction became loose after EMT. The epithelial protein marker E-cadherin was down-regulated and the mesenehymal protein markers vimentin and fibroneetin up-regulated. There were 51 miRNAs showing statistically significant changes of expression more than double （P 〈0.05） after EMT. Among them 18 were up-regulated and 33 down-regulated. Of them, mir-33a was down-regulated by 92.8% and mir-193a-3p by 86.5%. Real time quantitative RT-PCR showed that mir-33a was down-regulated by 73.1% and mir-193a-3p by 56.6%. Conclusion Epithelialmesenchymal transition has effects on the expression of miRNAs, and miRNAs may regulate the invasion and metastasis of lung cancer cells via EMT.