Effects of recombinant multi-CSF, GM-CSF, G-CSF and M-CSF on the proliferation and maturation of human AML in vitro.

To investigate the relative role of the individual hematopoietic growth factors in stimulating AML cell growth we compared the effects of recombinant (r) Multi-CSF (IL-3), rGM-CSF, rG-CSF and rM-CSF on DNA synthesis of AML blasts in culture. In order to establish the interrelationship between the proliferative effects exerted by these CSFs on AML cells, the ability of these factors to induce progressive monocytic or granulocytic maturation in AML blasts was also assessed. The studies were conducted in 25 cases of AML. They show that AML blasts often are responsive to at least one of the physiologic regulators but the patterns of response reveal a considerable heterogeneity among patients with AML. Although the cells react to these factors, they are usually inert in their capacity to mature, which indicates their intrinsic maturation defect.