Differentiation of human leukemia cells and its usefulness for clinical diagnosis.

Various chemical inducers have effects on the induction of terminal differentiation of human myelogenous leukemia cell lines. We studied morphological and functional changes of human leukemia cells freshly obtained from patients using 12-0-tetradecanoyl phorbol-13-acetate (TPA), retinoic acid (RA) or dimethyl sulphoxide (DMSO). The myeloid leukemia cells cultured with TPA became adherent to plastic culture dishes, and then developed macrophage-like morphology with long filamentous pseudopods within 48 h incubation. They showed marked enhancement of the ability to phagocytose latex particles. But these acquired properties did not always parallel each other, suggesting that the mechanism of functional maturation of leukemic cells induced by chemical agents was not identical with that of morphological changes. On the other hand, the lymphoid leukemia cells did not show morphological and functional changes when cultured with the above inducers. It is suggested that exposure of leukemic cells to TPA for relatively short times (12-24 h) may be useful for determining whether they are of myeloid or lymphoid origin. These characteristic changes were also observed in leukemic cells from the myeloid or lymphoid crisis of chronic myelogenous leukemia.