Comparative biochemical studies of adriamycin and daunomycin in leukemic cells.

Abstract

Summary Adriamycin (AM) and daunomycin (DM) were compared as inhibitors of nucleic acid and protein biosynthesis in L1210 leukemic cells. In vivo , both antibiotics markedly inhibited, without significant difference, the incorporation of the labeled precursors into DNA and RNA. In vitro , at a concentration of 5 or 10 eg/ml, DM was significantly more effective than AM in inhibiting DNA and RNA synthesis in L1210 leukemic cells. Results of studies with leukemic cells isolated from the blood of patients are the same as those obtained with L1210 cells in vitro . The reaction catalyzed in vitro by DNA polymerase, isolated from L1210 cells, was equally inhibited by AM and DM, although no effect on the enzyme was seen when the drugs were given in vivo . Studies with L1210 cells, resistant to AM or DM, suggest cross-resistance between the drugs.