A patient with erythroleukemia and heterozygous for the Mediterranean variant of the X-linked enzyme glucose-6-phosphate dehydrogenase (G6PD) was studied to determine the number and type of progenitor cells in which the disease arose.
A 3.7-kilobase (kb) genomic clone of the human beta-globin gene, including 1.5-kb upstream and approximately 0.5-kb downstream, was utilized in chromosomal in situ hybridization for precise mapping of the beta-globin locus on peripheral blood lymphocyte-derived metaphases from a normal male, and for further evaluation of a clonal t(7;11) (q22;p15) translocation on bone marrow-derived metaphases from a 46-year-old male with erythroleukemia.
To study the expression of globin genes in human cells, human epsilon-globin genes were transferred into a K562 cell line, Bos, which synthesizes very low amounts of epsilon-globin mRNA.
In addition, beta-globin gene expression has been evaluated in human erythroleukemia cells, K562 cells, and, although stable transformants with integrated beta-globin genes have been obtained, none of these transformants expressed the added beta-globin genes.
Murine erythroleukemia (MEL or Friend) cells grown in culture and induced to differentiate into cells resembling orthochromatic normoblasts provide a suitable system for uncovering molecular and cellular mechanisms of hemopoiesis and for understanding globin gene regulation.
Thus, the regulation of the expression of the cloned fetal A gamma-globin gene in murine erythroleukemia cells resembled that of cloned adult beta-globin genes.
We have analysed the expression of cloned human fetal gamma-globin genes introduced into murine erythroleukemia cells by a protoplast fusion procedure.
The specificity of expression of the isolated 5'-flanking sequences of the human beta- and epsilon-globin genes was examined in the K562 human erythroleukemia cell line, the murine erythroleukemia (MEL) cell, and in nonerythroid cell lines CV-1, HeLa-S3, and WI-38.
A different murine erythroleukemia cell line which does not differentiate in response to EP was found to have only the lower affinity binding sites for the hormone.
Introduction of a virus containing the beta-globin gene with introns into murine erythroleukemia cells resulted in inducible expression of human beta-globin RNA and protein, while the viruses containing the minigene were inactive.
K562 human erythroleukemia cells can be induced by hemin and other stimuli to produce hemoglobin and actively express epsilon- and gamma-globin genes but not the adult-like beta-globin gene.
K562 human erythroleukemia cells can be induced by hemin and other stimuli to produce hemoglobin and actively express epsilon- and gamma-globin genes but not the adult-like beta-globin gene.
We performed high-resolution mapping studies of the DNAse I-hypersensitive sites located just 5' to the human G gamma- and A gamma-globin genes of K562 erythroleukemia cells, in which these genes are constitutively expressed at low levels.
Furthermore, by primer extension of single-stranded oligonucleotide probes, we show that the theta 1-globin gene of humans is transcribed in an erythroleukemia cell line K562.
To determine the critical cis-acting elements, hybrid genes containing elements of the gamma and beta globin genes were transfected into K562 cells, a human erythroleukemia line.