子宫内膜癌干细胞分化过程中microRNA表达谱的鉴定及分析

Characterization of microRNA expression profile in endometrial cancer stem cells during differentiation

目的筛选子宫内膜癌干细胞分化过程中差异表达的microRNAs(miRNAs)并进行初步鉴定。方法无血清悬浮培养法富集子宫内膜癌干细胞,贴壁培养获得其分化细胞。利用microRNA芯片比较肿瘤干细胞及其分化细胞之间miRNAs的表达差异,挑选出有显著差异的miRNAs,通过RT-qPCR进行验证,应用TargetScan等数据库预测其靶基因;同时,芯片检测肿瘤干细胞及其分化细胞之间基因表达的差异,结合预测的miRNAs靶基因进行综合分析。结果 microRNA芯片筛选得到子宫内膜癌干细胞及其分化细胞之间差异表达(相差倍数2倍以上)的miRNAs有11个,其中在肿瘤干细胞中表达上调的miRNAs 10个,分别为miR-522、miR-139-3p、miR-520c-5p、miR-518d-5p、miR-146b-5p、miR-34a、miR-526a、miR-193a-3p、miR-221、miR-4674;在肿瘤干细胞中低表达的miRNA 1个,为miR-760。RT-qPCR检测结果显示,除miR-526a、miR-4674以外,其余9个miRNAs在肿瘤干细胞及分化细胞间的相对表达量均存在显著差异,与芯片检测结果一致。TargetScan、miRanda及miRTarBase在线数据库的交集中,筛选的miRNAs均可预测到靶基因。基因芯片检测肿瘤干细胞及其分化细胞,表达有显著性差异的基因共445个,其中207个在肿瘤干细胞中高表达,238个在肿瘤干细胞中低表达,与预测的miRNAs靶基因进行综合分析后发现,除miR-139-3p外,两者均有交集。结论子宫内膜癌干细胞分化过程中部分miRNAs的表达具有显著性变化,对此进行深入探索将为肿瘤干细胞的分化机制研究提供新的线索。

Objective To obtain comprehensive expression profile of microRNAs(miRNAs)in endometrial cancer stem cells(ECSCs)during differentiation.Methods ECSCs were enriched by spheroid formation and spontaneously differentiated into cancer cells by attached culture.We characterized miRNA expression in ECSCs and its differentiated cells using miRNA microarrays and verified the results by RT-qPCR.Meanwhile,we applied bioinformatic method to predict the target genes of the differentially expressed miRNAs.Furthermore,gene expression profile was detected by genomic microarray.Finally,we summarized the relationship between the predicted target genes of miRNAs and gene expression profile.Results We observed that 10 miRNAs were significantly upregulated in ECSCs,including miR-522,miR-139-3 p,miR-520 c-5 p,miR-518 d-5 p,miR-146 b-5 p,miR-34 a,miR-526 a,miR-193 a-3 p,miR-221,and miR-4674.Only 1 miRNA,miR-760,was downregulated in ECSCs.A total of11 differentially expressed miRNAs were identified by RT-qPCR.The results showed these differentially expressed miRNAs(except miR-526 a and miR-4674)were in accordance with those obtained by miRNA microarray analysis.By using bioinformatic approach,the target genes of these differentially expressed miRNAs could be found.The results of genomic microarray showed that 207 genes were more highly expressed and 238 genes were more lowly expressed in ECSCs compared with its differentiated cells.Analysis of the gene expression profile and the predicted target genes of miRNAs showed that some common genes except miR-139-3 p could be found.Conclusion Our study provides an available information about miRNAs and target genes from different starting points,such as ECSCs differentiation.Further studies are needed to ascertain the role of these miRNAs in ECSCs' differentiation.