HL60

HL-60 (Human promyelocytic leukemia cells) cell line derived from a patient with acute promyelocytic leukemia proliferates continuously in suspension culture in nutrient medium supplemented with fetal bovine serum, L-glutamine, HEPES and antibiotic chemicals. The HL-60 cells continuously proliferate in suspension culture with a doubling time of about 36-48 hours. Proliferation of HL-60 cells occurs through the transferrin and insulin receptors, which are expressed on cell surface. The requirement for insulin and transferrin is absolute, as HL-60 proliferation immediately ceases if either of these compounds is removed from the serum-free culture media (Breitman et al1., 1980). Spontaneous differentiation to mature granulocytes can be induced by compounds such as dimethylsulfoxide (DMSO), retinoic acid. Other compounds like 1,25-dihydroxyvitamin D3, 12-O-tetradecanoylphorbol-13-acetate (TPA) and GM-CSF can induce HL-60 to differentiate to monocyte, macrophagelike and eosinophil respectively.

The HL-60 cultured cell line provides a continuous source of human cells for studying the molecular events of myeloid differentiation and the effects of physiologic, pharmacologic, and virologic elements on this process. For examples, Gallagher et al2. (1979) report that the characterization of HL-60 cells from a patient with acute promyelocytic leukemia is predominantly a neutrophilic promyelocyte. HL-60 cell model was used to study the effect of DNA topoisomerase (topo) IIα and IIβ on differentiation and apoptosis of cells (Sugimoto et al3., 1998). Thus, HL-60 cell line provides a unique in vitro model system for studying the cellular and molecular events, especially in the dielectrophoresis study4 that aqueous environment, suspended and round cells are needed.