[The role of cytokines in the proliferation of leukemia cells in acute myelogenous leukemia].

Acute myelogenous leukemia is characterized by the infinite proliferation of malignant leukemia cells and by the impaired hematopoiesis. The proliferation of leukemia cells is supported by a small subpopulation, leukemic blast progenitors. Leukemic blast progenitors make leukemic blast colonies in methylcellulose culture. To determine the mechanism by which leukemia cells proliferate, we studied the role of several cytokines in the proliferation of leukemic blast progenitors in vitro. The findings indicated that there are at least three types in the regulation by cytokines of the leukemic cell growth. One is the stimulation of leukemic blast progenitors by colony-stimulating factors(CSFs) or interleukins(ILs) added in culture. These cytokines include granulocyte-CSF(G-CSF), granulocyte-macrophage CSF (GM-CSF), IL-3 and IL-1. The second is the autocrine growth mechanism. Leukemia cells by themselves produce and secrete G-CSF and GM-CSF, which stimulate the growth of leukemic blast progenitors. The third is a complex mechanism. IL-1, produced by leukemia cells or other cells, enhances the production of GM-CSF by leukemia cells, which stimulates the growth of leukemic blast progenitors. The precise mechanism by which each cytokine acts on leukemic blast progenitors should be determined to explore the mechanism of leukemia cell growth.