[The Relationship between MicroRNA Expression Profiling in Imatinib-Resistant Cell Line K562/G and Potential Mechanism through FOXO3/Bcl-6 Signaling Pathway].

To investigate the drug resistant related FOXO3/Bcl-6 signaling pathway in K562/G cell line and its related microRNA(miRNA) mechanisms.The drug resistance potency of imatinib on K562/G was detected by MTT assay. The expression of FOXO3 and Bcl-6 proteins in K562 and K562/G cells was detected by Western blot. Real-time PCR (RT-PCR) was used to detect the expression of FOXO3 and Bcl-6 mRNA. The miRNA expression profiling in K562 and K562/G cells was analyzed by microarray technique, and the miRNA targeted to FOXO/Bcl-6 signaling pathway was identified.The expression of FOXO3 and Bcl-6 protein was significantly increased in K562/G cells as compared with that in K562 cells (P<0.01), the expression level of Bcl-6 mRNA showed no increase in K562/G cells. However, FOXO3 mRNA was up-regulated in K562/G cells (P<0.05). MiRNA microarray results showed that 109 miRNAs were expressed differentially in K562 and K562/G cells. The expression of 81 miRNAs were up-regulated while 28 miRNAs were down-regulated. Through reverse prediction by bioinformatics, miR-6718-5p, miR-5195-5p, miR-4711-3p, miR-4763-5p, miR-4664-5p and miR-3176 were related to FOXO/Bcl-6 signaling pathway.The FOXO3/Bcl-6 signaling pathway contributes to imatinib resistance in K562/G cell line, and the miRNA expression profiles showed significant differences between K562/G and K562 cells.伊马替尼耐药K562/G的microRNA表达谱分析及与FOXO3/Bcl-6信号通路关系的研究.探讨CML耐药细胞株K562／G耐药相关的FOXO3/Bcl-6信号通路及相关microRNA(miRNA)机制.采用MTT法检测伊马替尼对K562／G的耐药性；采用Western blot法检测耐药株和敏感株细胞中FOXO3和Bcl-6蛋白的表达情况，实时荧光定量PCR检测FOXO3及 Bcl-6 mRNA的表达。运用miRNA芯片技术筛查K562与K562／G细胞之间差异表达的miRNA，进一步筛选FOXO3/Bcl-6信号通路的靶向miRNA.K562／G较K562细胞株的FOXO3及 Bcl-6蛋白表达均明显升高(P<0.01)；Bcl-6 mRNA的表达水平无明显差异，而K562/G 细胞中FOXO3 mRNA表达明显升高(P<0.05)。miRNA芯片结果显示，K562／G与K562细胞之间有109条miRNA存在显著的差异，其中上调miRNA为81个，下调miRNA有28个。经生物信息学反向预测，其中miR-6718-5p、miR-5195-5p、miR-4711-3p、miR-4763-5p、miR-4664-5p和miR-3176与该信号通路相关.伊马替尼耐药与FOXO3/Bcl-6信号通路相关，并且K562／G与K562细胞存在miRNA表达显著差异.