DNA breaks in P288 tumor cells in mice after treatment with daunorubicin and adriamycin

Abstract

Extensive DNA damage was found in tumor cells after therapeutic doses of daunorubicin and adriamycin (2.5 - 10 mg/kg) were administered to mice bearing lymphocytic leukemia (P-288). After low doses (0.6 mg/kg), DNA breaks were evident as early as 1-3 hr after daunorubicin and as determined with adriamycin the damage lasted as long as 72 hr. In a comparison, actinomycin D produced smaller amounts of damage by 3 hr after the administration of maximally tolerated doses (0.8 mg/kg) and even less after 0.4 mg/kg. These experiments indicate that the antitumor activity of daunorubicin and adriamycin in treated mice may result from damage to the cellular DNA.