Abstract
The human CD34 hematopoietic stem cell antigen is a highly glycosylated type I membrane protein of unknown function. CD34 is expressed on 1% to 4% of bone marrow cells, including pluripotent stem cells and committed progenitors of each hematopoietic lineage. CD34 has also been shown to be expressed on the small vessel endothelium of a variety of tissues and on a subset of bone marrow stromal cells. We have chosen to use the human CD34 gene as model to examine the transcription factors and cis-elements required for stem cell/progenitor cell-specific gene regulation. We show here that the CD34 gene is transcriptionally regulated in tissue culture cells. Using a luciferase reporter gene, we have isolated and characterized an active CD34 promoter. A CD34-luciferase construct, containing 4.5 kb of 5′ flanking DNA from a CD34 genomic clone, was 30-fold more active in CD34+ tissue culture cells than in HeLa cells. Sequences from the 3′ end of the CD34 gene were shown to have enhancing activity in CD34′ T-lymphoblastic RPMI-8402 cells and not in CD34 U937 cells or in nonhematopoietic HeLa cells. We also show that a cytidine-guanosine island in the 5′ end of the CD34 gene is heavily methylated in two CD34 hematopoietic cell lines and demethylated in two CD34+ cell lines. Analysis of the CD34 promoter should result in the identification of stem cell/progenitor cell-specific transcription factors and should provide a means to direct the expression of heterologous genes in hematopoietic stem cells and progenitors.
Original language | English (US) |
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Pages (from-to) | 3051-3059 |
Number of pages | 9 |
Journal | Blood |
Volume | 80 |
Issue number | 12 |
State | Published - Dec 15 1992 |
ASJC Scopus subject areas
- Biochemistry
- Immunology
- Hematology
- Cell Biology