The Effect And Relative Mechanisms Of MicroRNA-200a In Glioma

Objective To examine the expression of miR-200 a in glioma cells and patients,and to investigate the relationship between miR-200 a and maliglant biological behavior on glioma cells,and to analyze its target gene TGF-β2.Methods Real-time PCR was used to detect the expression of miR-200 a in 79 human glioma tissues and 15 normal brain tissues(from post-craniocerebral injury patients)and human glioma cell lines.After inhibiting or overexpressing mi R-200 a in glioma cell line(U251.A172),the colony formation ability was detected by clone formation assay,cell proliferation was examined by MTT assay,the invasion ability of glioma cells was detected by Transwell method.Targetscan software predicted complementary binding relationship between miR-200 a and TGF-β2 mRNA 3’UTR.Luciferase reporter assay examined the relationship.The changes of TGF-β2 were verified by western blot and qRT-PCR after transient transfection.Results The results of qRT-PCR showed that the expression of miR-200 a in glioma tissues was significantly lower than that in normal human brain tissues,and the expression level of miR-200 a decreased with the malignant degree of glioma(P <0.01).Compared with normal brain tissue,the expression of miR-200 a in glioma cell lines was significantly decreased(P <0.01).After transient transfection with mi R-200 a mimic and inhibitor in both cell lines,The level of miR-200 a was significantly increased and inhibited.Compared with the negative control group,the proliferation and invasive ability of the mimic group were inhibited,while the inhibitor group was significantly improved(P <0.05).Targetscan and luciferase reporter gene method confirmed TGF-β2 to be one of the target genes of mi R-200 a.Further study suggested that the expression of TGF-β2 mRNA and protein was significantly lower than that of the control group after transient transfection.(P <0.01)Conclusion The expression of miR-200 a was down-regulated in gliomas and negatively correlated with the degree of malignancy,suggesting that miR-200 a may be closely related to the development of gliomas.MiR-200 a inhibits the proliferation and invasion of human glioma cells,its mechanism may be related to its target gene TGF-β2,which may provide a new idea for molecular targeted therapy of glioma.