Cytotoxic effect of extracellular ATP on L1210 leukemic cells and normal hemopoietic stem cells.

The cytotoxic effect of extracellular adenosine triphosphate (ATP) was examined on normal murine hemopoietic stem cells and a representative leukemic cell line (L1210). After L1210 cells were incubated with 4 mM ATP for 3 h, 3H-thymidine incorporation was almost completely inhibited. The number of viable L1210 cells was also significantly decreased and L1210 colony formation was suppressed to approximately 30% of the control level after treatment. The CFU-GM survival rate was reduced to 70%, however, CFU-S and marrow nucleated cell numbers were not changed after the same treatment with ATP. All mice that were injected with the untreated mixture of normal marrow cells (3.3 x 10(4)) and L1210 cells (3.3 x 10(3)) died of leukemia within 18 days. On the contrary, 85% of the recipients given ATP-treated grafts survived more than 70 days. These findings indicate that ATP extra vivo treatment is useful for purging the residual leukemic cells in autologous bone marrow transplantation.