Mechanisms Underlying The Role Of MiR-200a In The Migration And Invasion Of Glioma Cells

ObjectivesTo explore the effects of miR-200a on cell migration and invasion in glioma cells andfurther study on its possible mechanism.MethodsCombined with the early research results of our group, the expression ofmiR-200a in glioma cell lines and glioma tissue were detected by real-time PCR.Differential expression levels of miR-200a in U87cells were achieved by transfectingwith miR-200a inhibitors and mimics. The proliferation、migration and invasionabilities were detected by MTS、Wound-healing assay and Transwell experiment inU87cells respectively.Bioinformatics was used to predict downstream target genes of miR-200a. Andits potential target genes were classified by DAVID online software. The regulatoryeffect of miR-200a on its potential target genes was further studied by luciferase assayand Western blot assay．ResultsThe miR-200a expression in high-grade glioma cell lines were significantlyhigher than low-grade glioma cell lines (P<0.05). This is consistent with the findingsof the early research of our group. Overexpression of miR-200a promoted migrationand invasion ability in U87cell lines (P<0.05), while miR-200a inhibitors generatedthe opposite result, however, the cell proliferation abilities were not significantlyaffected (P>0.05).The online software analysis showed that many potential target genes ofmiR-200a，including PTEN, NCAM1, MAP2K4, UBAP1etc. were associated withtumor cell migration and invasion. Those potential target genes involved the pathwaysas Tight junction, mTOR, etc. Which were important for tumor cell migration andinvasion.U87glioma cells were transfected with miR-200a mimics and endogenous PTENand NCAM1gene expression was detected by Western blots. We discovered thatmiR-200a directly reduced the expression of PTEN and NCAM1at the protein levels.The down-regulation of PTEN promoted expression of the downstream protein AKTand increased S-phase entry. Furthermore, we used luciferase assays to demonstratethat miR-200a interacts with predicted target sites in the3’untranslated region ofPTEN and NCAM1. In conclusion, our study suggest that miR-200a is involved inglioma cell migration and invasion by targeting PTEN and NCAM1.Conclusions1.The miR-200a expression in high-grade glioma cell lines were significantly higherthan low-grade glioma cell lines, and miR-200a may play a role of oncogene inglioma cell.2.miR-200a can promote migration and invasion ability in U87gliomacells.3.miR-200a is involved in glioma cell migration and invasion by targetingPTEN and NCAM1, and involved in the regulation of PTEN_PI3K/AKT pathway.