O^6-甲基鸟嘌呤-DNA甲基转移酶在恶性脑胶质瘤组织中的表达及意义

Expression and significance of MGMT in malignant glioma tissues

目的探讨O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)在恶性脑胶质瘤组织中的表达及其与预后的关系。方法选取2011年1月至2016年1月间中山市陈星海医院收治的经手术切除的64例恶性脑胶质瘤(Ⅲ、Ⅳ级)患者,采用免疫组化法检测肿瘤组织中MGMT蛋白的表达,评定治疗效果,追踪生存时间(OS),评价MGMT与生存时间之间的关系。结果 MGMT阳性表达率为62.5%,MGMT阴性表达率为37.5%。WHOⅢ级恶性胶质瘤组织中MGMT阳性表达率与Ⅳ级比较,差异无统计学意义(P>0.05);但Ⅳ级恶性胶质瘤MGMT(++)表达率为60.0%,明显高于Ⅲ级的48.3%,差异有统计学意义(P<0.05)。MGMT阴性患者总有效率(ORR)为62.5%,高于阳性患者的17.5%;与MGMT(-)比较,MGMT(+)和MGMT(++)平均OS均降低,差异均有统计学意义(均P<0.05)。MGMT阳性患者最长无进展生存时间(PFS)为32个月,MGMT(-)最长PFS为40个月。结论 MGMT表达与脑胶质瘤恶性程度有关,表达强度越高,恶性程度越高,检测MGMT可一定程度预知脑胶质瘤治疗的有效率及预后。

Objective To study the expression of O6-methylguanine-DNA methyltransferase（ MGMT） in malignant glioma tissues and its relation to prognosis. Methods A total of 64 patients with grade III and IV malignant gliomas diagnosed by surgical resection were selected from January 2011 to January2016 at Chen Xing-hai Hospital of Zhongshan. Immunohistochemical method was used to detect the expression of MGMT in malignant glioma tissues and treatment efficacy was analyzed. Overall survival（ OS） was tracked and the relation between MGMT and survival time was evaluated. Results The positive expression rate of MGMT was 62. 5% and the negative expression rate of MGMT was 37. 5%. There was no significant difference in the positive rate of MGMT between patients with WHO grade Ⅲ and Ⅳ malignant glioma（ P〈0. 05）. However,the expression rate of MGMT（ ＋ ＋） was 60. 0% in patients with WHO IV malignant glioma,which was significantly higher than 48. 3% of patients with grade Ⅲ malignant glioma（ P〈0. 05）.The overall response rate（ ORR） was 62. 5% in patients with negative expression of MGMT,which was higher than 17. 5% of patients with positive expression of MGMT（ P〈0. 05）. Compare with MGMT（-）,the average OS significant decreased for MGMT（ ＋） and MGMT（ ＋ ＋）（ P〈0. 05）. The longest progression-free survival time（ PFS） was 32 months for MGMT positive and 40 months for MGMT（-）.Conclusion The expression of MGMT is related to the degree of malignant glioma. The higher the intensity of expression is the higher the degree of malignancy is. The detection of MGMT could predict the efficiency and prognosis of glioma to some extent.