Association Between MGMT Promoter Hypermethylation and p53 Mutation in Glioblastoma

Abstract

O⁶-methylguanine–DNA methyltransferase (MGMT) is a DNA repair enzyme that removes alkyl groups from the O⁶ position of guanine. MGMT is transcriptionally silenced by promoter hypermethylation in several human neoplasia. We used methylation-specific PCR (MSP) to analyze the MGMT promoter methylation status of 50 glioblastoma tumors. Hypermethylation was detected in 24 of 50 (48%) samples. We also analyzed mutant p53 expression by immunohistochemical analysis of glaioblastoma tissue samples. A significant association was found between MGMT methylation and p53 mutation status (p<. 05). These results suggested that epigenetic inactivation of MGMT plays an important role in the survival of glioblastoma patients and this inactivated gene involved in p53 mutation.

Keywords:

• Hypermethylation
• Glioblastoma
• O⁶-methylguanine–DNA methyltransferase
• p53