Differential induction of adult and fetal globin gene expression in the human CML cell subline KU-812F/33.

Various chemicals which are known to have positive effects on differentiation of some erythroid cell lines were tested on a human chronic myelogenous leukemia cell line, KU-812F. Succinic acid, 5-azacytidine, daunomycin, and hemin showed a positive effect. Among them, hemin and 5-azacytidine were the most effective inducers for erythroid differentiation of KU-812F cells. Dimethylsulfoxide, cytosine arabinofuranoside, and sodium n-butyrate showed no effect. In addition, subclone KU-812F/33 derived from the KU-812F cell line showed differential expression of the beta- and gamma-globin genes in the presence of either 2 microM 5-azacytidine or 40 microM hemin. Hemoglobin synthesis in differentiated KU-812F/33 cells was analyzed by isoelectric focusing gel electrophoresis, and S1 mapping analysis of beta- and gamma-globin mRNA was performed. After treatment with 5-azacytidine, the beta-globin gene expression was predominantly enhanced (18.75-fold higher level of beta-globin mRNA). After treatment with hemin, the most notable increase was in the gamma-globin gene expression (1.83-fold higher level of gamma-globin mRNA), while no increment of beta-globin was observed.