沉默lncRNA GIHCG通过上调miR-146a-3p增加胶质瘤细胞放射敏感性

目的 探讨lncRNA GIHCG对胶质瘤细胞放射敏感性的影响及作用机制。方法 qRT-PCR实验检测人脑正常胶质细胞HEB和胶质瘤细胞系U251、A172、SHG139、U87中GIHCG和miR-146a-3p表达水平。以U251和SHG139细胞为研究对象,沉默GIHCG表达或过表达miR-146a-3p后,MTT检测细胞增殖,流式细胞仪检测细胞凋亡,克隆形成实验检测细胞放射敏感性,蛋白印迹法检测CDK1、CyclinD1、Bcl-2和Bax蛋白表达水平。生物信息学软件预测GIHCG与miR-146a-3p存在结合位点,双荧光素酶报告基因实验和qRT-PCR实验验证GIHCG与miR-146a-3p的靶向关系。结果 与HEB细胞比较,胶质瘤U87、U251、A172和SHG139细胞中GIHCG表达升高(P<0.05),miR-146a-3p表达降低(P<0.05)。沉默GIHCG表达或过表达miR-146a-3p,U251和SHG139细胞存活率、存活分数、CDK1、CyclinD1和Bcl-2蛋白表达降低(P<0.05),凋亡率和Bax蛋白表达升高(P<0.05)。GIHCG在U251和SHG139细胞中靶向负调控miR-146a-3p表达,抑制miR-146a-3p表达逆转了沉默GIHCG对胶质瘤细胞增殖、凋亡及放射敏感性的影响。结论 沉默GIHCG表达可促进miR-146a-3p表达,从而增强胶质瘤细胞的放射敏感性。

Silencing lncRNA GIHCG increases radiosensitivity of glioma cells by up-regulating miR-146a-3p

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 MTT assay, cell apoptosis was detected by flow cytometry, cell radiosensitivity was detected by colony formation assay and the expression levels ofCDK1,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,CyclinD1 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.