title: Induction of C/EBPalpha activity alters gene expression and differentiation of human CD34+ cells.
abstract: The CCAAT/enhancer binding protein alpha (C/EBPalpha) belongs to a family of transcription factors that are involved in the differentiation process of numerous tissues, including the liver and hematopoietic cells. C/EBPalpha(-/-) mice show a block in hematopoietic differentiation, with an accumulation of myeloblasts and an absence of mature granulocytes, whereas expression of C/EBPalpha in leukemia cell lines leads to granulocytic differentiation. Recently, dominant-negative mutations in the C/EBPalpha gene and down-regulation of C/EBPalpha by AML1-ETO, an AML associated fusion protein, have been identified in acute myelogenous leukemia (AML). To better understand the role of C/EBPalpha in the lineage commitment and differentiation of hematopoietic progenitors, we transduced primary human CD34(+) cells with a retroviral construct that expresses the C/EBPalpha cDNA fused in-frame with the estrogen receptor ligand-binding domain. Induction of C/EBPalpha function in primary human CD34(+) cells, by the addition of beta-estradiol, leads to granulocytic differentiation and inhibits erythrocyte differentiation. Using Affymetrix (Santa Clara, CA) oligonucleotide arrays we have identified C/EBPalpha target genes in primary human hematopoietic cells, including granulocyte-specific genes that are involved in hematopoietic differentiation and inhibitor of differentiation 1 (Id1), a transcriptional repressor known to interfere with erythrocyte differentiation. Given the known differences in murine and human promoter regulatory sequences, this inducible system allows the identification of transcription factor target genes in a physiologic, human hematopoietic progenitor cell background.
authors.affiliation: Laboratory of Molecular Aspects of Hematopoiesis, Sloan-Kettering Institute, Division of Hematologic Oncology, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY 10021, USA.
authors.forename: Jörg
authors.initials: J
authors.lastname: Cammenga
authors.forename: James C
authors.initials: JC
authors.lastname: Mulloy
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Berguido
authors.forename: Donal
authors.initials: D
authors.lastname: MacGrogan
authors.forename: Agnes
authors.initials: A
authors.lastname: Viale
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Nimer
mesh_terms: D001665:Binding Sites; D015153:Blotting, Western; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000172:deficiency / Q000235:genetics* / Q000502:physiology; D002454:Cell Differentiation; D004912:Erythrocytes / Q000166:cytology; D015672:Erythroid Precursor Cells / Q000737:chemistry; D004958:Estradiol / Q000494:pharmacology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D020869:Gene Expression Profiling; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D006801:Humans; D051798:Inhibitor of Differentiation Protein 1; D009504:Neutrophils / Q000166:cytology; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000032:analysis; D011960:Receptors, Estrogen / Q000378:metabolism; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D012190:Retroviridae / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics; D014162:Transfection
chemical_list: D022763:CCAAT-Enhancer-Binding Protein-alpha; C497453:ID1 protein, human; D051798:Inhibitor of Differentiation Protein 1; D011960:Receptors, Estrogen; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D004958:Estradiol; D012313:RNA