Control of normal differentiation of myeloid leukemic cells. VI. Inhibition of cell multiplication and the formation of macrophages.

D+ but not D- myeloid leukemic cells can be induced by the appropriate conditioned medium or by serum from endotoxin treated mice, to undergo cell migration in agar, cell attachment to the surface of a Petri dish and differentiation to mature macrophages and granulocytes. Inhibition of cell multiplication by cytosine arabinoside, hydroxyurea, mitomycin C, thymidine, 5-bromodeoxyuridine, 5-iododeoxyuridine, 5-fluorodeoxyuridine or actinomycin D, but not by vinblastine or cycloheximide, induced cell migration, cell attachment to the Petri dish and the formation of macrophages in D+ cells. There was no induction of cell migration or formation of macrophages and a much lower induction of cell attachment in D- cells. The induction of these changes in D+ cells required protein synthesis and the inhibitors showed the same toxicity for D+ and D- cells. The results indicate, that the inhibitors induced specific surface membrane changes in D+ but not in D- cells.