ITGB2促进胶质瘤细胞增殖并受E2F2调控

ITGB2 promotes the proliferation of glioma cells and is regulated by E2F2

目的探讨整合素亚单位β2(ITGB2)在胶质瘤中的表达、功能及其调控机制。方法收集2018年6月至2019年6月手术切除的25例胶质瘤组织样本以及其邻近的非肿瘤脑组织样本,采用实时定量PCR检测ITGB2 mRNA的表达。体外培养正常人小胶质细胞系(HMC3)和胶质瘤细胞系(A172、T98G、U138-MG),转染E2F2、ITGB2小干扰RNA调控细胞基因表达,CCK-8法和EdU染色法检测细胞增殖,利用流式细胞术检测细胞周期分布,双荧光素酶报告基因实验验证E2F2与ITGB2启动子区域的结合关系,利用免疫印迹法检测E2F2对ITGB2蛋白表达的影响。结果与瘤周非肿瘤脑组织相比,胶质瘤组织ITGB2 mRNA表达明显上调。敲低ITGB2表达抑制体外培养胶质瘤细胞的增殖,并诱导细胞发生周期阻滞。E2F2结合于ITGB2启动子区域,过表达E2F2促进ITGB2蛋白表达,敲低E2F2抑制ITGB2蛋白表达。过表达E2F2逆转敲低ITGB2对胶质瘤细胞生长的抑制作用。结论ITGB2在胶质瘤细胞中高表达,且促进胶质瘤细胞增殖,其高表达受E2F2调控。

Objective To explore the expression,function and regulatory mechanism of integrin subunit beta 2(ITGB2)in glioma.Methods The expressions of ITGB2 mRNA in glioma tissue and adjacent non-tumor brain tissue samples which were collected from 25 patients with glioma undergoing surgical resection from June 2018 to June 2019 was detected by real-time quantitative PCR.Glioma cell lines(A172,T98G,U138-MG)were cultured in vitro.E2F2 and ITGB2 small interfering RNAs were transfected to regulate the gene expression of cells.Cell proliferation was detected by CCK-8 assay and EdU staining,and cell cycle distribution was detected by flow cytometry.The binding relationship between E2F2 and the promoter region of ITGB2 was verified by dual luciferase reporter gene assay,and the influence of E2F2 on the expression of ITGB2 protein was detected by Western blotting.Results Compared with the non-tumor brain tissues adjacent to the tumor,the expression of ITGB2 mRNA in glioma tissues was significantly upregulated.Knockdown of ITGB2 expression inhibited the proliferation of glioma cells in vitro and induced cell cycle arrest.E2F2 bound to the promoter region of ITGB2.Overexpression of E2F2 promoted the expression of ITGB2 protein,and knockdown of E2F2 inhibited the expression of ITGB2 protein.Overexpression of E2F2 reversed the inhibitory effect of knockdown of ITGB2 on the growth of glioma cells.Conclusion ITGB2 is highly expressed in glioma tissues and promotes glioma cell proliferation,and its high expression is regulated by E2F2.