DNA alkylation at O6 position of guanine leading to apoptosis (O6-alkylguanine)

DNA alkylation at the O6 position of guanine refers to the covalent modification of the oxygen atom at the sixth position on guanine bases in DNA, most commonly by methyl or other alkyl groups. This lesion is primarily induced by exposure to certain chemotherapeutic agents (e.g., temozolomide) and environmental carcinogens. The resulting adduct, such as O6-methylguanine (O6MeG), is highly mutagenic and cytotoxic. If not repaired before replication, these lesions are recognized by the mismatch repair (MMR) system. MMR attempts futile cycles of repair on O6MeG:T mismatches, which can result in DNA double-strand breaks (DSBs). These DSBs trigger apoptosis.

Other names

O6-methylguanineO6MeGGuanine O6-alkylation

Induction of O6-methylguanine leading to futile mismatch repair cycles and apoptosis.