MGMT基因启动子甲基化与MGMT蛋白和NF-κB在脑胶质瘤的表达及意义

The significance of MGMT promoter methylation and the expression of MGMT and NF-κB in glioma

目的探讨MGMT和NF-κB在脑胶质瘤中的表达及两者的相关性和MGMT基因启动子甲基化与其蛋白表达的相关性分析。方法采用免疫组化EnVision法检测MGMT和NF-κB在42例不同级别脑胶质瘤石蜡标本中的表达,运用MSP方法检测MGMT基因启动子甲基化状况。结果 (1)MGMT在低级别组胶质瘤中的表达率为73.7%;在高级别组中其表达率为21.7%。(2)NF-κB在低级别组胶质瘤中的表达率为52.6%,在高级别组中的表达率为60.9%。(3)42例胶质瘤中MGMT基因启动子甲基化发生率为50%,其中MGMT蛋白阳性的胶质瘤,启动子甲基化发生率为26.3%;MGMT蛋白表达阴性的胶质瘤,启动子甲基化发生率为69.6%;MGMT蛋白表达阳性率与其基因启动子甲基化呈负相关。(4)MGMT与NF-κB两者表达无相关性。结论 MGMT蛋白表达随胶质瘤的级别增高而下降,NF-κB与MGMT与胶质瘤级别无相关性。

Objective To investigate the expression of MGMT and NF-KB in glioma and correlation between MGMT and NF-κB,MGMT gene promoter methylation and its protein expression. Methods Immunohistochemistry assay was conducted to detect the expression of MGMT and NF-KB in gliomas;methylation specific PCR（ MSP）was used to analyze the MGMT promoter methylation in glioma. Results （ 1 ） The ratio of MGMT expression was 73.7% in the low grade group glioma; its expression was 21.7% in the high grade group. （2）NF-KB expression rate was 52. 6% in the low grade group glioma,expression of the high grade group was 60.9%. （3）In the 42 cases,the level of MGMT promoter methylalon was 50% ;it was in 19 cases that MGMT protein expresses positively, and among which 5 cases were methylated, so the positive expression rate was 26.3%. MGMT protein expression had negative correlation with its promoter methylation. （4） There was no correlation between MGMT and NF-KB expressions. Conclusions MGMT expression decrease following the level of glioma rise and there is no correlation comparison the expression of NF-KB, and MGMT with glioma level.