miR-592 induces apoptotic cell death in human U251 cells / 中国神经精神疾病杂志

ABSTRACT

Objective To investigate the role of miR-592 in the Glioma.Methods We first analyzed the expression of miR-592 in Glioma tissues from patients by quantitative PCR.We transfected U251 cells with miR-592 mimics and then detected the growth of cells by MTT assay.We performed dual-luciferase reporter assay and western blot assay to examine whether Runx2 was the direct target of miR-592 in U251 cells.In order to test whether Runx2 was the functional target of miR-592,we determined the cell growth curve by down-regulating the level of Runx2.Moreover,we also detected the apoptosis of U251 after Runx2 knockdown.Results The expression of miR-592 was significantly reduced in glioma tissues (t=2.752,P--0.013).Over-expression miR-592 remarkably increased the apoptotic rate of U251 cells compared with the control group (t=2.127,P=0.031;t=2.284,P=0.026).Flow cytometry analysis showed that MiR-592 significantly promoted apoptotic cell death of U251 cells Apoptosis rate was 7.2％±0.68％ in miR-592 group and 17.47％±1.45％ in control group (t=3.294,P=0.007).The results of double luciferase assay and Western blot assay showed that miR-592 directly targeted the 3'Runx2 of-UTR to inhibit the level of Runx2 protein.The effect of down-regulation of Runx2 on the growth of U251 cells was detected,the results showed that growth was significantly slower in the cells transfected with Runx2 siRNA than in those without Runx2 siRNA (t=3.124,P=0.O11).Detection of cycle by flow cytometry showed that runx2 down-regulated the apoptosis rate of U251 cells.Tumor growth curve showed that overexpression of miR-592 significantly inhibited tumor growth and the down regulation of Runx2 expresssion also significantly inhibited tumor growth.Conclusion miR-592 suppresses the growth and promotes the apoptotic rate of U251 cells by targeting Runx2.