DNA-isophosphoramide mustard adducts (IPM-DNA adducts) (IPM-DNA adducts)

DNA-isophosphoramide mustard adducts are the primary therapeutic lesions formed following the administration of the alkylating agent ifosfamide. Ifosfamide is a prodrug that requires metabolic activation by hepatic cytochrome P450 enzymes, specifically CYP3A4 and CYP2B6, to form the active alkylating species, isophosphoramide mustard (IPM) (StatPearls, NBK541054). IPM covalently binds to DNA, predominantly at the N7 position of guanine residues, resulting in the formation of mono-adducts and DNA cross-links (PubChem, CID 3690). These cross-links, which can be interstrand or intrastrand, create physical barriers that stall DNA replication forks and inhibit RNA polymerase-mediated transcription (PubMed, 11821454). The persistence of these adducts activates the DNA damage response, leading to cell cycle arrest and the induction of apoptosis in rapidly dividing malignant cells (Cancer Research, 61(12):4756). While these adducts are essential for the drug's anti-cancer efficacy against sarcomas and germ cell tumors, the metabolic process also generates toxic byproducts like acrolein and chloroacetaldehyde, which are responsible for significant side effects such as hemorrhagic cystitis and neurotoxicity (NIH, LiverTox).

Other names

Ifosfamide-DNA adductsIsophosphoramide mustard-DNA cross-linksN7-guanine isophosphoramide mustard adductsDNA-IPM lesionsIfosfamide-induced DNA damage

Covalent alkylation of DNA bases, primarily at the N7 position of guanine, leading to the formation of interstrand and intrastrand cross-links that inhibit DNA replication and transcription.