miR-124 increases the radiosensitivity of glioblastoma cells through targeting STAT3 / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the expression of miR-124 in glioblastoma (GBM) cell lines LN229 and LN229R,as well as the regulatory mechanism of miR-124 on radiosensitivity of LN229R cells.Methods miR-124 mimic (miR-124) and negative control (miR-NC),STAT3 overexpression plasmid (STAT3) and pcDNA3.1 vector (pcDNA) were transfected or co-transfected into radioresistant glioma cells LN229R.qRT-PCR was employed to analyze the expression of miR-124 in LN229 and LN229R cells.The survival rate and sensitivity-related parameters of LN229R cells at different doses were analyzed by cloning formation assay.Cell apoptosis of LN229R was evaluated by flow cytometry.Targeting gene of miR-124 was predicted using Targetscan software and verified by the double-luciferase reporter assay.Western blot assay was performed to detect STAT3 protein expression.Results The expression of miR-124 in LN229R cells (0.32 ± 0.03) was significantly lower than that in LN229 cells (1.02 ± 0.09) (t =12.780,P＜0.05).Transfection of miR-124 mimics promoted the expression of miR-124 in LN229R cells (4.02±0.39) compared with miR-NC group (0.95±0.06) (t=13.476,P＜0.05).After 8 Gy irradiation,the survival rate of LN229R cells transfected with miR-124 mimics (0.003 ± 0.000 4) was significantly lower than that in miR-NC group (0.033±0.005 0) (t=5.655,P＜0.05),and the apoptosis rate (22.34±2.42) ％ was significantly higher than that in miR-NC group (4.69 ± 0.51) ％ (t =12.361,P＜0.05).STAT3 was identified to be a target gene of miR-124.Exogenous restoration of STAT3 reversed the inhibitory effect of miR-124 on LN229R cell survival.Conclusion miR-124 increases the radiosensitivity of LN229R cells by targeting STAT3.