MGMT在脑胶质瘤组织中的表达及其与患者生存期的关系

背景与目的:目前的研究已经证实DNA修复酶——6-氧-甲基鸟嘌呤DNA甲基转移酶(O6-methylguanine-DNAmethyltransferase,MGMT)在脑胶质瘤组织中的表达与肿瘤的耐药性有一定的关系,并且能够影响肿瘤的化疗效果。本研究通过分析MGMT在脑胶质瘤组织中的表达及其与患者生存期的关系,为基于耐药机制上的脑胶质瘤分子分类提供参考资料。方法:用组织芯片技术和免疫组织化学方法检测311例脑胶质瘤石蜡标本中MGMT的表达情况,并对所有患者进行手术后的5年随访。结果:MGMT表达阳性者126例,占40.51%(126/311)。其中,星形细胞瘤中阳性率为50.41%(61/121),少枝胶质细胞瘤中为25.71%(18/70),少枝星形细胞瘤中为28.13%(18/64),胶质母细胞瘤中为51.79%(29/56);在Ⅰ～Ⅱ级胶质瘤中,MGMT表达的阳性率为36.56%(68/186),而在Ⅲ～Ⅳ级胶质瘤中为46.40%(58/125),经χ2检验分析,两者之间有显著性差异(P<0.001);将MGMT的表达与患者生存期的关系绘制成Kaplan-Meier生存曲线,并进行log-rank分析,MGMT表达阳性者与阴性者之间的差异有显著性(P<0.05)。结论:MGMT在脑胶质瘤的异常表达与肿瘤的组织类型、病理级别有关,MGMT表达阳性患者的生存期明显低于表达阴性的患者。

Relationship between the expression of O6-methylguanine-DNA methyltransferase in glioma and the survival time of patients

BACKGROUND & OBJECTIVE: Previous studies showed that the DNA-repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT) is one of drug resistant factors that affect chemosensibility of glioma. This study was to analyze the relationship between the expression of MGMT in glioma and the survival time of patients,and supply references to make molecular classification for glioma based on drug resistant mechanism. METHODS: MGMT expression in 311 glioma specimens was examined by tissue array technology and immunohistochemistry method, all patients had been followed up for 5 years, and the materials were analyzed statistically. RESULTS: The positive expression of MGMT was 126 in 311 gliomas (40.51%), among them, 61 in 121 astrocytomas (50.41%), 18 in 70 oligodendrogliomas (25.71%), 18 in 64 oligoastrocytomas (28.13%), 29 in 56 glioblastomas (51.79%); 68 in 186 grade I-II gliomas (36.56%), and 58 in 125 grade III-IV gliomas (46.40%). The difference of MGMT expression between grade I-II and grade III-IV gliomas was significant (P< 0.001). According to Kaplan-Meier's survival curves and log-rank test, patients with MGMT expression showed a shorter survival time than those with no MGMT expression (P< 0.05). CONCLUSION: MGMT expression in glioma correlates with histopathological type and tumor grade. Patients with MGMT expression show a shorter survival time than those with no MGMT expression.