Inhibition of hematopoiesis by competitive binding of transcription factor PU.1.
Transcription factors have been shown to play a role as "master switch" factors in the programming of hematopoietic cell commitment and differentiation. PU.1 is a hematopoietic-specific member of the Ets family of transcription factors. In human bone marrow CD34-enriched progenitor cells, PU.1 expression was upregulated during the early phases of granulocytic/monocytic differentiation, preceding expression of its target genes encoding CD11b and the macrophage-colony-stimulating factor receptor, whereas PU.1 was expressed at stable levels throughout erythroid differentiation. To study PU.1 function, we synthesized double-stranded phosphorothioate oligonucleotides containing a characterized PU.1 site and demonstrated their ability to specifically compete for PU.1 DNA binding. When added to CD34+ cells in vitro, wild-type PU.1-binding oligonucleotides significantly blocked hematopoietic colony formation, whereas mutated PU.1 oligonucleotides which no longer bind PU.1 had no specific inhibitory effect. These results demonstrate that PU.1 is developmentally upregulated during normal human myelopoiesis and that the function of PU.1 is critical for the development of in vitro hematopoiesis.
Voso
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MT
Beth Israel Hospital, Department of Medicine, Harvard Medical School, Boston, MA 02215.
Burn
T C
TC
Wulf
G
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Lim
B
B
Leone
G
G
Tenen
D G
DG
D015703:Antigens, CD / Q000032:analysis / Q000096:biosynthesis; D018952:Antigens, CD34; D001483:Base Sequence; D001667:Binding, Competitive; D001854:Bone Marrow Cells; D018845:CD11 Antigens; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D050981:Erythroid-Specific DNA-Binding Factors; D015870:Gene Expression / Q000187:drug effects; D006410:Hematopoiesis / Q000187:drug effects / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009838:Oligodeoxyribonucleotides / Q000378:metabolism / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000096:biosynthesis; D015682:Retroviridae Proteins, Oncogenic; D013873:Thionucleotides / Q000494:pharmacology; D014157:Transcription Factors / Q000096:biosynthesis*
D015703:Antigens, CD; D018952:Antigens, CD34; D018845:CD11 Antigens; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D015682:Retroviridae Proteins, Oncogenic; D013873:Thionucleotides; D014157:Transcription Factors; C062022:v-Spi-1 protein, Friend spleen focus-forming virus; D016173:Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor