[Proliferation and differentiation of leukemic cells in acute myelocytic leukemia]

Acute myelocytic leukemia is characterized as a malignant disease with excessive accumulation of leukemic cells and deterioration of hematopoiesis. We studied the mechanism by which leukemic cells proliferated in patients. The indefinite growth of leukemic cells is supported by leukemic blast progenitors with a self-renewal capacity. Hematopoietic growth factors, such as granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) or stem cell factor (SCF), have been revealed to stimulate the growth of leukemic blast progenitors. Furthermore, leukemic cells themselves produce and secrete hematopoietic factors that stimulate leukemic blast progenitors. The so-called autocrine growth mechanism has been postulated to play an important role in the pathophysiology of acute myelocytic leukemia. Leukemic cells show terminal differentiation under certain circumstances. For example, leukemic cells differentiate to neutrophils or macrophages in suspension culture. Leukemic cells of erythroleukemia (FAB M6) differentiate to granulocytic and erythrocytic lineages. The mechanisms involved in the proliferation and differentiation of leukemic cells in acute myelocytic leukemia are discussed in the article.