PTEN表达对恶性脑胶质瘤细胞放射敏感性的影响及其机制研究

Effect of PTEN expression on radiosensitivity of malignant glioma cells and its mechanism

目的研究第10号染色体缺失性磷酸酶和张力蛋白同源物(PTEN)表达对恶性脑胶质瘤细胞放射敏感性的影响及其机制。方法采用实时荧光定量聚合酶链反应(RT-qPCR)和Western blot方法检测恶性脑胶质瘤及瘤旁正常组织和细胞的PTEN mRNA和蛋白表达量。对恶性脑胶质瘤T98G细胞进行梯度剂量X线(0、2、4、6 Gy)照射,RT-qPCR和Western blot检测T98G细胞的PTEN表达量。结果与癌旁正常组织相比,恶性脑胶质瘤组织的PTEN mRNA和蛋白表达量均显著降低(均P<0.01)。恶性脑胶质瘤U251细胞和T98G细胞的PTEN mRNA和蛋白表达量明显低于正常脑胶质HEB细胞(P<0.05~0.01);T98G细胞的PTEN表达量随着X线放射剂量增加而升高。结论下调PTEN基因的表达能够激活PI3K-AKT-GSK3β信号通路,从而降低恶性脑胶质瘤细胞的放射敏感性。

Objective To investigate the effect of chromosome 10 deletion phosphatase and tensin homolog(PTEN)expression on radiosensitivity of malignant glioma cells and its mechanism.Methods Real time quantitative polymerase chain reaction(RT-qPCR)and Western blot were used to detect the expression of PTEN mRNA and protein in malignant glioma and adjacent normal tissues and cells.The expression of PTEN was detected by RT-qPCR and Western blot.Results Compared with the normal tissues,PTEN mRNA and protein expression in malignant glioma were significantly decreased(P<0.01).The expression of PTEN mRNA and protein in U251 cells and T98G cells of malignant glioma was significantly lower than that of normal brain gliocytes(P<0.05-0.01).The PTEN expression of T98G cells increased with the increase of X-ray dose.Conclusion Down regulation of PTEN gene expression can activate PI3K-AKT-GSK3βsignal pathway,thereby reducing the radiosensitivity of malignant glioma cell.