Induction by phorbol esters of macrophage differentiation in human leukaemia cell lines does not require cell division.

Phorbol esters can induce differentiation into macrophage-like cells in the two human myeloid leukaemia cell lines HL-60 and KG-1. We investigated the requirement for DNA synthesis in this differentiation process. We found that phorbol ester-induced differentiation of blast cells into cells with the morphologic, histochemical, and phagocytic characteristics of macrophages did not require 3H-thymidine incorporation. Our results indicate that phorbol ester induced macrophage differentiation does not require DNA synthesis.