Protection of human myeloid leukemic cells against doxorubicin-induced apoptosis by granulocyte-macrophage colony-stimulating factor and interleukin 3

Hematopoietic cells require certain cytokines to maintain viability by preventing apoptotic cell death. These cytokines can also protect leukemic cell lines against induction of apoptosis by cytotoxic anticancer compounds. We now show that the cytokines granulocyte-macrophage colony-stimulating factor and interleukin 3 can protect primary human myeloid leukemic cells against doxorubicin-induced apoptosis. Protection was detected in cells from 72% of the myeloid leukemic patients tested. The results indicate that these, and perhaps other, hematopoietic cytokines can decrease the effectiveness of cytotoxic anticancer therapy in some human myeloid leukemias. Leukemic cell sensitization to cytotoxic therapy may, therefore, require decreasing the availability of certain cytokines.