Tumour promoters induce macrophage differentiation in human myeloid cells from patients with acute and chronic myelogenous leukaemia.

Twelve-O-tetradecanoyl phorbol-13-acetate (TPA) and other tumour promoter plant diterpenes transformed myeloid cells from peripheral blood, bone marrow and spleen from patients with chronic and acute myeloid leukaemia and acute myelomonocytic leukaemia into macrophage-like cells. This transformation resulted in cessation of cell multiplication, adherence of the cells to the surface of the culture dish, and acquisition of phagocytic activity, Fc receptors and enzymatic content characteristic of the monocyte-macrophage pathway of differentiation. The fact that tumour promoters induce differentiation in human myeloid leukaemia cells and not in similar cells from non-leukaemic conditions suggest their possible application in diagnosis and chemotherapy.