Silencing lncRNA GIHCG increases radiosensitivity of glioma cells by up-regulating miR-146a-3p / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the effect of lncRNA GIHCG on the radiosensitivity of glioma cells and its mechanism.Methods The expression levels of GIHCG and miR-146a-3p in human brain normal glial cells HEB and glioma cell lines U251,A172,SHG139 and U87 were quantitatively measured by qRT-PCR assay.U251 and SHG139 cells were used for subsequent experiment.After silencing the expression of GIHCG or overexpressing miR-146a-3p in U251 and SHG139 cells,cell proliferation was detected by MTI assay,cell apoptosis was detected by flow cytometry,cell radiosensitivity was detected by colony formation assay and the expression levels of CDK1,CyclinD1,Bcl-2 and Bax proteins were measured by Western blot.The bioinformatics software predicted the presence of a binding site for GIHCG and miR-146a-3p.Dual luciferase reporter gene assay and qRT-PCR assay were adopted to verify the targeting relationship between GIHCG and miR-146a-3p.Results Compared with HEB cells,the expression of GIHCG was significantly up-regulated in glioma U87,U251,A172 and SHG139 cells (all P＜0.05),whereas that of miR-146a-3p was remarkably down-regulated (P＜0.05).Silencing GIHCG expression or overexpression of miR-146a-3p significantly decreased the U251 and SHG139 cell survival rate,survival fraction and the expression of CDK1,CyclinDl and Bcl-2 proteins (all P＜0.05),whereas considerably increased the apoptotic rate and expression of Bax protein (both P＜0.05).GIHCG performed targeted negative regulation of miR-146a-3p expression in U251 and SHG139 cells and inhibition of miR-146a-3p expression reversed the effect of silencing GIHCG on proliferation,apoptosis and radiosensitivity of glioma cells.Conclusion Silencing GIHCG expression up-regulates the expression of miR-146a-3p,thereby enhancing the radiosensitivity of glioma cells.