Stimulatory effect of tumor necrosis factor-α on the growth of CMK, a human megakaryoblastic leukemia cell line

Abstract

Recombinant human tumor necrosis factor-α (TNF-α) was found to stimulate the growth of CMK, a human megakaryoblastic leukemia cell line. This stimulatory effect of TNF-α was blocked by anti-TNF-α antibody, but antibodies to recombinant human interleukin 3, granulocyte-macrophage colony-stimulating factor and interleukin 6 (all growth factors for CMK cells) did not reduce the stimulatory effect of TNF-α. Scatchard analysis showed that CMK cells expressed TNF-α receptors on the cell surface. The growth of CMK cells was also stimulated by lymphotoxin, which shares the same receptor as TNF-α. These results suggest that TNF-α stimulated the growth of CMK cells directly via its specific receptor.