Accumulation of leukemic cell DNA strand breaks with adriamycin and cytosine arabinoside

Adriamycin (doxorubicin) and cytosine arabinoside (Ara-C) induce single strand DNA breaks and DNA fragmentation. In view of the therapeutic efficacy of adriamycin in combination with Ara-C in the treatment of human acute non-lymphocytic leukemia, we have attempted to assess the accumulation of DNA strand breaks and DNA fragmentation with these agents by alkaline elution analysis. Although a less than additive enhancement was noted for the elution of pulse labelled, replicating DNA, the results demonstrate an additive effect of adriamycin and Ara-C on the elution of pre-labelled L1210 murine leukemia DNA.