Overexpression of GATA-2 inhibits erythroid and promotes megakaryocyte differentiation

GATA-1 and GATA-2 transcription factors are required for effective hematopoiesis. These regulatory proteins present overlapping yet distinct patterns of expression in hematopoietic cells. Absence of GATA-2 leads to defective hematopoiesis and an embryonic lethal phenotype. Disruption of GATA-1 resul...

Full description

Saved in:
Bibliographic Details
Published in:Experimental hematology 2000-12, Vol.28 (12), p.1423-1431
Main Authors: Ikonomi, Pranvera, Rivera, Candido E, Riordan, Michael, Washington, Glennelle, Schechter, Alan N, Noguchi, Constance T
Format: Article
Language:English
Subjects:
Adult
Cell Differentiation
Differentiation
DNA-Binding Proteins - genetics
DNA-Binding Proteins - physiology
Erythroid Precursor Cells - cytology
Erythroid Precursor Cells - metabolism
Erythroid progenitors
Flow Cytometry
GATA-2
GATA2 Transcription Factor
Gene Expression
Hematopoiesis
Hematopoietic Stem Cells - cytology
Hematopoietic Stem Cells - metabolism
Humans
K562
Leukemia, Erythroblastic, Acute - metabolism
Megakaryocyte
Megakaryocytes - cytology
Megakaryocytes - metabolism
Reverse Transcriptase Polymerase Chain Reaction
RNA, Messenger - analysis
Transcription Factors - genetics
Transcription Factors - physiology
Transfection
Tumor Cells, Cultured
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:GATA-1 and GATA-2 transcription factors are required for effective hematopoiesis. These regulatory proteins present overlapping yet distinct patterns of expression in hematopoietic cells. Absence of GATA-2 leads to defective hematopoiesis and an embryonic lethal phenotype. Disruption of GATA-1 results in a compensatory increase in GATA-2 in early erythroid cells and incomplete erythropoiesis with embryos dying at 11.5 days. We examine the specific role of GATA-2 later in hematopoiesis, during erythroid differentiation. Stable K562 cell lines expressing various levels of GATA-2 were generated using a GATA-2 expression plasmid. Overexpression of GATA-2 transcripts was determined by quantitative polymerase chain reaction (PCR). Cytospin smears, growth curve analysis, PCR, and flow cytometry were used to examine the effects of increased levels of GATA-2 in altering cell phenotype and activation of megakaryocytic markers. Human progenitor erythroid cells also were transfected with a GATA-2 expression vector. Growth curve analysis, benzidine staining, and high-performance liquid chromatographic analysis were used to study the effects of GATA-2 on erythroid maturation and proliferation. K562/GATA-2 cell lines expressing high levels of GATA-2 mRNA showed a marked decrease in proliferation and a shift in phenotype toward the megakaryocyte lineage. Ploidy analyses showed that these cell lines developed a multinuclear phenotype, including tetraploids and octaploids. PCR analysis showed activation of megakaryocyte-specific genes including thrombopoietin receptor ( c-mpl). Surface expression of platelet glycoprotein receptors Ib/IX (CD42b/CD42a) and IIb/IIIa (CD41/CD61) also was demonstrated by flow cytometry. In primary human adult erythroid cultures transfected with a GATA-2 expression vector, production of total hemoglobin and cell proliferation decreased in a dose-dependent manner. GATA-2 plays an important role in deciding cell lineage throughout hematopoiesis, and increased expression of GATA-2 determines megakaryocytic differentiation. Downregulation of GATA-2 is required for erythroid differentiation.
ISSN:0301-472X
1873-2399
DOI:10.1016/S0301-472X(00)00553-1