title: [Expression of genes for human globin in the cell line K-562: an experimental model for the study of fetal erythropoiesis].
abstract: Human leukemia K-562(S) cells are a useful model system to study the relationship between cell proliferation and induced erythroid differentiation. In these studies K-562(S) cells were cultured in alpha -medium, 10% fetal calf serum and induced to express erythroid genes by 75 microM hemin, 1.2 mM butyric acid or 1.5 ng/ml actinomycin D. Cell number was determined using a ZF Coulter Counter and the increase in the proportion of hemoglobin-containing cells was detected by a specific colorimetric reaction with benzidine. The characterization of the synthesized hemoglobins was performed by cellulose-acetate gel electrophoresis of post-mitochondrial supernatants. By cloning K-562(S) cells in semi-solid medium (O,33% agar) containing 75 microM hemin a variant cell line, denominated K-562(S6), have been isolated which does not undergo terminal cell division but does express human globin genes and accumulates on the average 12 pg of Hb/cell. K-562(S6) cells accumulate, upon exposure to 75 microM hemin, mostly Hb Gower 1 (zeta 2 epsilon 2) and low amounts of Hb X (epsilon 2 gamma 2) and Hb Portland (zeta 2 gamma 2), being suitable for studies focused on the expression of embryonic globin genes and on the molecular mechanisms controlling the switching from embryonic-type to fetal-type hemoglobin accumulation, when in the human embryo zeta and epsilon globin genes become less active, being sharply increased accumulation of alpha and gamma globin chains.
mesh_terms: D002452:Cell Count; D002460:Cell Line; D004588:Electrophoresis, Cellulose Acetate; D004920:Erythropoiesis; D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics*; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007700:Kinetics; D007938:Leukemia / Q000378:metabolism
chemical_list: D006454:Hemoglobins; D005914:Globins
vernacular_title: Espressione dei geni per le globine umane nella linea cellulare K-562: un modello sperimentale per lo studio dell'eritropoiesi fetale.