Ametantrone is an inhibitor of topoisomerase II. It induces double-strand breaks in SV40 DNA in the presence, but not absence, of topoisomerase II and induces single-strand breaks in DNA in NCI H187 cells. It also induces interstrand DNA cross-links in HeLa S3 cells at a minimum concentration of 4.1 μM. Ametantrone is cytotoxic to NCI H187 and HL-60 cells (IC50s = 112 and 0.44 μM, respectively). It inhibits tumor growth in a Ridgway osteogenic sarcoma mouse model when administered at a dose of 5 mg/kg, however, it increases tumor growth in mouse models of mammary adenocarcinoma and colon adenocarcinoma 11a.
