Doxorubicin and ricin, a strongly synergistic combination in mouse leukemia

The effect of combinations of doxorubicin (Adriamycin) and the cancerostatic plant lectin ricin on L1210 leukemic cells in mice was assessed by end-point dilution and spleen-colony assays. The combinations, which were well-tolerated by the mice, acted synergistically on leukemic cells in liver, spleen, and brain. In the bone marrow, a dramatically synergistic effect was obtained with combinations that had only slight effect on the survival of normal stem cells.