Methylation of O6-methyl guanine methyltransferase gene promoter in meningiomas--comparison between tumor grades I, II, and III.

BACKGROUND Meningiomas are the second most common primary intracranial tumors after gliomas. Epigenetic biomarkers such as DNA methylation, which is found in many tumors and is thus important in tumorigenesis can help diagnose meningiomas and predict response to adjuvant chemotherapy. We investigated aberrant O6- methyl guanine methyltransferase (MGMT) methylation in meningiomas. MATERIALS AND METHODS Sixty-one patients were classified according to the WHO grading, and MGMT promoter methylation status was examined via the methylation-Specific PCR(MSP) method. RESULTS MGMT promoter methylation was found in 22.2% of grade I, 35% of grade I with atypical features, 36% of grade II, and 42.9% of grade III tumors. CONCLUSIONS There was an increase, albeit not statistically significant, in MGMT methylation with a rise in the tumor grade. Higher methylation levels were also observed in the male gender.