Cytotoxicity of adriamycin combined with methotrexate against L1210 leukemia in mice.

The combination of adriamycin and methotrexate was found in mice to be synergistic in cytotoxicity to L1210 leukemia cells for a range of time intervals between the two agents. Cytotoxicity for normal hematopoietic stem cells was less than additive. Spleen colony assays were used to quantitate both cell populations. Increase in life-span assays yielded similar results. Also, the extent of synergy was dependent on the dose of adriamycin only.