title: FLI-1 is a suppressor of erythroid differentiation in human hematopoietic cells.
abstract: The FLI-1 oncogene, a member of the ETS family of transcription factors, is associated with both normal and abnormal hematopoietic cell growth and lineage-specific differentiation. We have previously shown that overexpression of FLI-1 in pluripotent human hematopoietic cells leads to the induction of a megakaryocytic phenotype. In this report we show that FLI-1 also acts as an inhibitor of erythroid differentiation. Following the induction of erythroid differentiation, pluripotent cells express reduced levels of FLI-1. In contrast, when FLI-1 is overexpressed in these cells, the levels of erythroid markers are reduced. The ability of FLI-1 overexpressing cells to respond to erythroid-specific inducers such as hemin and Ara-C is also inhibited, and the uninduced cells show a reduced level of the erythroid-associated GATA-1 transcription factor mRNA. Furthermore, expression of a GATA-1 promoter-driven reporter construct in K562 cells is inhibited by co-transfection with a construct expressing FLI-1. Our results support the hypothesis that FLI-1 can act both positively and negatively in the regulation of hematopoietic cell differentiation, and that inhibition of GATA-1 expression may contribute to FLI-1-mediated inhibition of erythroid differentiation.
authors.affiliation: Intramural Research Support Program, SAIC Frederick, MD, USA.
authors.forename: M
authors.initials: M
authors.lastname: Athanasiou
authors.forename: G
authors.initials: G
authors.lastname: Mavrothalassitis
authors.forename: L
authors.initials: L
authors.lastname: Sun-Hoffman
authors.forename: D G
authors.initials: DG
authors.lastname: Blair
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D003561:Cytarabine / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004912:Erythrocytes / Q000166:cytology; D015672:Erythroid Precursor Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D004920:Erythropoiesis / Q000187:drug effects / Q000502:physiology*; D050982:GATA1 Transcription Factor; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D006427:Hemin / Q000494:pharmacology; D006801:Humans; D020014:K562 Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008533:Megakaryocytes / Q000166:cytology; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D051789:Proto-Oncogene Protein c-fli-1; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000502:physiology; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D009363:Neoplasm Proteins; D051789:Proto-Oncogene Protein c-fli-1; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D003561:Cytarabine; D006427:Hemin