[Purging of leukemic cells from mouse marrow and tumor suspensions with lysosomotropic agent N-dodecyl morpholine]

The lysosomotropic agent N-dodecyl morpholine (NDM) showed a marked killing of mice leukemic cells in vitro: 100% killing of L7811 leukemic cells (10(6) cells/ml) at a concentration of 15 micrograms/ml. Bone marrow of 615 mice containing 5% L7811 leukemic cells was treated with NDM and then infused into normal 615 mice. Mean survival times (MST) were 16.3 +/- 1.78 days and 15.8 +/- 2.32 days for control group and solvent group respectively, while the MST of groups treated with NDM were more than 40 days. When the marrow was infused into lethally irradiated mice, those mice receiving NDM-purged marrow died of radiation disease instead of leukemia. But when the number of marrow cells infused was increased to 2 x 10(6) cells/mouse, the mice survived for significantly longer times than did control group mice or those of the group infused with 10(6) cells/mouse.