Azacytidine plus verapamil induces the differentiation of a newly characterized biphenotypic human myeloid-B lymphoid leukemic cell line BW-90.

The biphenotypic cell line BW-90 was established from the peripheral blood of a a patient with a refractory acute myelomonocytic leukemia. All cells were HLADr+, CD34-. Dual color flow cytometry showed simultaneous expression of myeloid (CD33) and B-lymphoid surface markers (CD19) on 60% of cells, CD54 on 91% of cells.

Effects of simultaneous and sequential exposure to granulocytic and monocytic inducers on the choice of differentiation pathway in HL-60 promyelocytic leukemia cells.

HL-60 promyelocytic leukemic cells were induced to differentiate by the combination of two alternative inducers: phorbol-12-myristate 13-acetate (PMA) and either dimethyl sulfoxide (DMSO) or retinoic acid (RA). Simultaneous exposure to optimal concentrations of PMA and either DMSO or RA potentiated PMA-induced differentiation into monocyte-macrophages. Granulocytic inducers combined with lower concentration of PMA competed with the latter for the differentiation pathway, producing monocyte-macrophages, granulocytes, paramyeloid and giant multinucleated cells.

Mononuclear macrophage (M-CFC) colony formation in semisolid media in the absence of exogenous GM-CSF.

Human fetal bone marrow (FBM) cells were examined for the ability to form colonies in the absence of exogenous colony-stimulating factor (CSF) in double layer agar, methylcellulose (MC), and in agar-MC (agar underlayer, MC overlayer) culture systems. Without exogenous CSF, macrophage colonies (M-CFC) were formed in a combined culture of agar and MC. Aggregates of 5-40 cells were observed on day 7.