In vitro growth of human myeloid leukemia bone marrow cells in liquid culture.

The myelopoietic cell growth, proliferation and differentiation of human bone marrow cells from 20 acute leukemia patients and 12 control subjects were studied by the diffusion chamber technique. The differences in proliferation patterns between normal and leukemic marrow cells are reported. Acute nonlymphatic leukemia cells do not differentiate in vitro, and retain the cytochemical characteristics of the inoculated cells. Leukemic blasts grow to form agglomerates while normal or more differentiated cells produce a population diffused over the membrane. No colony-stimulating factor is necessary for growth to occur, even for the leukemic population, which is unable to produce colony-stimulating activity.