Malignant Biological Behavior And Mechanism Of MiR-21 In Promoting Retinoblastoma Weri-RB-1 Cells

Objective: We employed miRNA-21(miR-21)inhibitor to explore the relationships between mi R-21 and phosphatase and tensin homolog(PTEN)/ phosphatidylinositol-3-OH kinase(PI3K)/AKT signal,p53/p21 signal in the progression of retinoblastoma(RB),and reveal a new cell therapy for RB.Methods: Quantitative real-time PCR(qRT-PCR)was used to analyze the expression of miR-21 in RB tissues and retinal normal tissues.We transfected Weri-Rb-1 cells with miR-21 control or mi R-21 inhibitor via LipofectaminTM 2000.After 48 h,qRT-PCR was employed to determine the expression of miR-21;Cell viability was analyzed by MTT assay;Flow cytometry with Annexin V-FITC/PI reagent was used to detect cell apoptosis;And the protein levels of Bax,Bcl-2,PDCD4,MMPs and PTEN were examined by western blot.Results: Compared with retinal normal tissues,miR-21 was overexpressed in RB tissues with significant difference(P<0.01).In Weri-Rb-1 cells,miR-21 inhibitor transfection suppressed the expression of miR-21 and cell viability(P<0.01).Compared with mi R-21 NC,miR-21 inhibitor incubation improved cell apoptosis rate and the expression of PDCD4 and Bax(P<0.01).Meanwhile,miR-21 suppressed cell migration and invasion,and inhibited the protein levels of MMPs(P<0.01).MiR-21 inhibitor affected the activation of PTEN/PI3K/AKT signaling pathway.Also,miR-21 inhibitor promoted cell cycle arrest by activating the p53/p21 signaling pathway.Conclusions: MiR-21 inhibitor significantly suppressed cell proliferation,migration and invasion and cell cycle arrest,which was closely associated with the PTEN/PI3K/AKT signal and p53/p21 signal.These findings revealed the molecular basis of miR-21 in RB and provided a new action targets and means for cell therapy in RB.