In Human Bladder Cancer, DNA Methylation Regulating Expression Mechanism And Function Of MicroRNA-203

Objective:Firstly, bioinformatics were applied to predict the microRNAs hypermethlated in bladder cancer. Secondly, to study the effects of 5-Aza-CdR on bladder cancer cells and microRNAs predicted above. Thirdly, to confirm the hypermethlated microRNAs and their target genes. Finally, to illustrate the effects of these microRNAs on the tumorgenisis of bladder cancer.Methods:Firstly, the hypermethlated microRNAs were predicted by several databases online.The target genes of these microRNAs were predicted by TargetScan, PicTar, miRanda,and Functional cluster analysises.such as GO,pathway were use to study the biogenisis, molecular mechanism, molecular components and signaling pathways of these target genes. Secondly, after treatment of 5-Aza-CdR, MTT and flow cytometry were used to anlyse the effects of 5-Aza-CdR on bladder cancer cells 5637 and BIU-87. quantitative RT-PCR assay was used to detect the different expression levels in 5-Aza-CdR treated and untreated cells. The hypermethylation of these microRNAs was tested by MSP and BSP. Thirdly, real-time PCR and western blot confirmed that the target genes of these microRNAs were regulated by methylation. Finally, the effects of these microRNAs on proliferation, mestasis and apoptosis were study through MTT, mestasis experiments and flow cytometry.Conclusions:Firstly,13 microRNAs were related to DNA methylation by bioinformatics. Secondly,5-Aza-CdR can suppress the proliferation of 5637 and BIU-87 and inhibit cell cycles. Demethylation of hsa-miR-203 lead to up-regulation of its expression. hsa-miR-203 suppressed the proliferationand inhibited the mestasis of bladder cancer cells after overexpressing hsa-miR-203 exogenously, which suggest that hsa-miRNA-203 may serve as a tumor suppressor in bladder cancer.