中文摘要：

目的：检测猿猴病毒40（simian virus 40,SV40）小T抗原（small T antigen,ST）诱导人支气管上皮细胞（human bronchialepithelial cell,HBE）恶性转化中miRNAs的表达谱,寻找与细胞转化相关的miRNAs。方法：选择HBE、HBER和HBERST细胞株,提取总RNA,利用miRNA芯片和实时荧光定量PCR技术检测和验证永生化HBE、HBER和HBERST细胞中差异表达的miRNAs。通过细胞生长曲线检测、细胞周期分析、细胞克隆形成试验等确证与SV40 ST诱导HBE细胞恶性转化相关的miRNAs。结果：在HBE、HBER和HBERST细胞856个miRNA的表达谱中筛选出6个与SV40 ST诱导细胞转化相关的miRNA,2个表达上调（miR-20a和miR-27a）.4个表达下调（let-7d,let-7f,miR-1246和miR-3746）。抑制miR-27a能减缓HBERST细胞的增殖速度（P〈0.01）,延长细胞在G0～G1期的停留时间（P〈0.01）和降低HBERST细胞在软琼脂上形成克隆的数目（P〈0.01）。结论：miR-27a的异常表达参与了SV40ST诱导的HBE细胞恶性转化。

英文摘要：

OBJECTIVE：In order to identify the effect and mechanism of miRNAs involved in carcinogenesis, we evaluated the miRNA expression profiles at different stages of HBE cell transformation.METHODS：HBE,HBER and HBERST cells were collected and cultured.The comparison of differential expression profiles among these three cells was performed and analyzed by miRNA microarray.Then,the differentially expressed miRNAs were selected for validation by semi-quantitative real-time PCR.Finally,the functions of these miRNAs were examined using cell growth cure,cell cycle analysis and colony formation assay.RESULTS：856 human miRNAs were tested with microarray analysis in HBE,HBER and HBERST cell lines.Six differentially expressed miRNAs were found in HBERST compared with HBE and HBER cell lines,including 4 down-regulated and 2 up-regulated miRNAs.Among these miRNAs,miR- 27a was found to be upregulated by SV40 ST in HBE cells.Suppression of miR-27a expression in HBERST cells inhibited the rate of cell growth（P 0.01） and led to cell cycle arrested in the GO-Gl phase（P 0.01）.In addition,suppression of miR-27a in HBERST cells attenuated the capacity of cell colony formation（P 0.01）.CONCLUSION：Promotion of cell growth by miR-27a overexpression might be responsible for the viral oncoprotein small T antigen-induced malignant transformation.