Abstract
A mature hematopoietic cell represents the end product of a stepwise differentiation process. As a model system for studying differentiation, the human promyelocytic leukemia cell line HL-60 undergoes terminal monocytic/macrophagic differentiation following exposure to either phorbol 12-myristate 13-acetate or 1,25-dihydroxyvitamin D3. We have derived and analyzed a variant HL-60 cell line, 1F10, that permits the study of several intermediate steps in the myeloid differentiation process. These intermediate steps are documented by cell cycle data and phenotype analysis as well as markers such as c-myc, c-fms, and both subunits of ferritin.