MGMT (6-O-methylguanine-DNA methyltransferase) is a DNA repair enzyme with the ability to protect cells from carcinogenic effects of alkylating agents by removing adducts from the O(6) position of guanine, restoring guanine to its normal form without causing DNA breaks. MGMT protects cells from alkylating toxins, and is an important factor in drug resistance to alkylating therapeutic agents Indeed, MGMT silencing has been linked to mutations in other tumor-related genes including silencing of p53, k-ras gene mutations, and methylation of CDKN1A gene as well as CDKN2A gene.
