Deregulation Of MicroRNA-188 In Prostate Carcinoma And Effects On Proliferation And Metatasis Of Prostate Cancer In Vitro.

Objective To measure the expression level of MicroRNA-188(miR-188)in prostate carcinoma and investigate its biological functions on prostate carcinoma cell lines.Methods In 30 PCa and 40 BPH samples,quantificational real-time polymerase chain reaction(qRT-PCR)was used to test the expression of miR-188 in prostate tissues.In different prostate cell lines,miR-188 expression was also tested using qRT-PCR.miR-188 mimic was re-introduced into PC-3 and LNCaP cells by Lipfectamine 2000.We explored the function of miR-188 on PCa cells with colony formation assays?Transwell migration and invasion assays.To investigate the candidate targets for miR-188 using prediction algorithm provided by miRanda.Luciferase activity was measured using the dual luciferase reporter assay system.Results We found that the expression level of miR-188 was significantly lower in PCa tissues than pericarcinous and BPH tissues(P<0.05),while miR-188 expression was comparable in pericarcinous and BPH tissues(P>0.05).We also found that miR-188 was significantly down-regulated in PCa cell lines than in RWPE-1(P=0.0012).By colony formation assays we observed that ectopic miR-188 expression significantly inhibited colony formation compared to control PC-3 and LNCaP cells(P<0.0001).We next found ectopic miR-188 expression significantly reduced the cell invasion and migration compared to control PC-3 and LNCaP cells(P<0.05).Through computational analysis,the binding site for miR-188 at 3'-UTRof LAPTM4? was depicted.The luciferase-based assay validated LAPTM4? was regulated by miR-188.Conclusion miR-188 was significantly down-regulated in PCa.Restoration of miR-188 in PCa cells significantly suppresses proliferation,migration and invasion in vitro.miR-188 can negatively regulate LAPTM4? expression by directly binding to its 3'UTR.