Induction of DNA degradation in vivo by adriamycin.

The anthracycline antibiotic adriamycin (Ad) induced degradation (single-strand breaks) of cell DNA in vivo in murine L1210 leukemia cells. Measurement was made by alkaline sucrose gradient methods. Exposure of isolated DNA to Ad had little effect; the in vivo DNA strand breaks were probably due to the action of nucleases on DNA distorted by bound Ad. Toxicity of Ad to postmitotic cells such as cardiac cells could be mediated by this mechanism, since it could be demonstrated in periods substantially shorter than the cell generation time and thus could be responsible for interphase death.