γ-Interferon (IFN-γ) has previously been found to induce monocytic differentiation in established leukemic cell lines, such as HL-60 and U937. The aim of the present sudy was to evaluate the differentiative effect of highly purified recombinant (r)IFN-γ on fresh bone marrow cells from patients with acute nonlymphocytic leukemia (n = 11) or myelodysplastic syndromes (n=3). Blast cells were cultured in suspension in the presence or absence of rIFN-γ (10-103 U/ml). While 6 out of 14 cases were unresponsive to rIFN-γ in vitro, the remaining 8 patients showed a significant increase (0.05 > p > 0.001) in the percentage of cells expressing C3bi receptors, detected by OKM1 (median value in control cell, 9.5; median value in rIFN-γ-treated cells, 31) and Mo1 (8.5 vs. 36), and in the percentage of cells expressing the monocytic antigens detected by Mo2 (8 vs. 28) and MY4 (6.5 vs. 32.5). In the responsive patients morphologic changes consistent with monocytic maturation, as well as a strong increase of α-naphthyl acetate esterase activity and of nitroblue tetrazolium reducing capability were observed upon culture with rIFN-γ. We conclude that (a) rIFN-γ may induce in vitro monocytic differentiation of blasts from acute nonlymphocytic leukemia and myelodysplastic syndrome patients, and that (b) this agent should be investigated for its capacity to be active in vivo.
|Number of pages||5|
|Publication status||Published - 1988|
ASJC Scopus subject areas
- Cancer Research