[Induction of myelogenous differentiation: a therapeutic possibility for preleukemia and acute leukemia?].

Human acute myelogenous leukemia often arises from a transformation at the stem cell level leading to a block in differentiation. The malignant cell, therefore, remains in the proliferative pool and rapidly accumulates. In preleukemia, also known as myelodysplastic syndromes, the malignant clone is already established, leading to disturbed hematopoiesis. One therapeutic approach, therefore, might be to overcome this block in differentiation and thus shift the cell from the proliferative into the differentiating pool. For several years now research in leukemia has focused on study of the proliferation and differentiation of normal and leukemic hematopoietic cells. Numerous substances have been identified which are able to trigger differentiation in myeloid cells, including the retinoids, vitamin D, tumor necrosis factor and hematopoietic hormones. The possible role of these agents in the treatment of preleukemia and acute myelogenous leukemias is discussed.