AML1-MTG8 leukemic protein induces the expression of granulocyte colony-stimulating factor (G-CSF) receptor through the up-regulation of CCAAT/enhancer binding protein epsilon

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 288-296 ◽  
Author(s):  
Kimiko Shimizu ◽  
Issay Kitabayashi ◽  
Nanao Kamada ◽  
Tatsuo Abe ◽  
Nobuo Maseki ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Binding Protein ◽  
Ectopic Expression ◽  
Precursor Cells ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
G Cells ◽  
Enhancer Binding Protein ◽  
Dependent Cell ◽  
Stimulating Factor

The t(8;21) translocation is one of the most frequent chromosomal abnormalities associated with acute myeloid leukemia (AML). In this translocation, the AML1 (CBFA2/PEBP2aB) gene is disrupted and fused to the MTG8 (ETO) gene. The ectopic expression of the resulting AML1-MTG8 fusion gene product in L-G and 32Dcl3 murine myeloid precursor cells stimulates cell proliferation without inducing morphologic terminal differentiation into mature granulocytes in response to granulocyte-colony stimulating factor (G-CSF). This study found that the ectopic expression of AML1-MTG8 elevates the expression of the G-CSF receptor (G-CSFR). Analysis of the promoter region of the G-CSFR gene revealed that up-regulation of G-CSFR expression by AML1-MTG8 does not depend on the AML1-binding sequence, but on the C/EBP (CCAAT/enhancer binding protein) binding site. The results suggest that the overproduction of G-CSFR is at least partly mediated by C/EBPɛ, whose expression is activated by AML1-MTG8. The ectopic expression of G-CSFR in L-G cells induced cell proliferation in response to G-CSF, but did not inhibit cell differentiation into mature neutrophils. Overexpression of C/EBPɛ in L-G cells also stimulated G-CSF–dependent cell proliferation. High expression levels of G-CSFR were also found in the leukemic cells of AML patients with t(8;21). Therefore, G-CSF–dependent cell proliferation of myeloid precursor cells may be implicated in leukemogenesis.

AML1-MTG8 leukemic protein induces the expression of granulocyte colony-stimulating factor (G-CSF) receptor through the up-regulation of CCAAT/enhancer binding protein epsilon

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 288-296 ◽  
Author(s):  
Kimiko Shimizu ◽  
Issay Kitabayashi ◽  
Nanao Kamada ◽  
Tatsuo Abe ◽  
Nobuo Maseki ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Binding Protein ◽  
Ectopic Expression ◽  
Precursor Cells ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
G Cells ◽  
Enhancer Binding Protein ◽  
Dependent Cell ◽  
Stimulating Factor

Abstract The t(8;21) translocation is one of the most frequent chromosomal abnormalities associated with acute myeloid leukemia (AML). In this translocation, the AML1 (CBFA2/PEBP2aB) gene is disrupted and fused to the MTG8 (ETO) gene. The ectopic expression of the resulting AML1-MTG8 fusion gene product in L-G and 32Dcl3 murine myeloid precursor cells stimulates cell proliferation without inducing morphologic terminal differentiation into mature granulocytes in response to granulocyte-colony stimulating factor (G-CSF). This study found that the ectopic expression of AML1-MTG8 elevates the expression of the G-CSF receptor (G-CSFR). Analysis of the promoter region of the G-CSFR gene revealed that up-regulation of G-CSFR expression by AML1-MTG8 does not depend on the AML1-binding sequence, but on the C/EBP (CCAAT/enhancer binding protein) binding site. The results suggest that the overproduction of G-CSFR is at least partly mediated by C/EBPɛ, whose expression is activated by AML1-MTG8. The ectopic expression of G-CSFR in L-G cells induced cell proliferation in response to G-CSF, but did not inhibit cell differentiation into mature neutrophils. Overexpression of C/EBPɛ in L-G cells also stimulated G-CSF–dependent cell proliferation. High expression levels of G-CSFR were also found in the leukemic cells of AML patients with t(8;21). Therefore, G-CSF–dependent cell proliferation of myeloid precursor cells may be implicated in leukemogenesis.

Granulocyte colony-stimulating factor regulates myeloid differentiation through CCAAT/enhancer-binding protein ε

Blood ◽  
2001 ◽  
Vol 98 (4) ◽  
pp. 897-905 ◽  
Author(s):  
Hideaki Nakajima ◽  
James N. Ihle
Keyword(s):  
Molecular Mechanisms ◽  
Binding Protein ◽  
Hematopoietic Cells ◽  
Myeloid Differentiation ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Granulocytic Differentiation ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Stimulating Factor

Granulocyte colony-stimulating factor (G-CSF) is a major cytokine that regulates proliferation and differentiation of myeloid cells, although the underlying mechanisms by which G-CSF controls myeloid differentiation are largely unknown. Differentiation of hematopoietic cells is regulated by lineage-specific transcription factors, and gene-targeting studies previously revealed the critical roles of CCAAT/enhancer-binding protein (C/EBP) α and C/EBPε, respectively, in the early and mid-late stages of granulocyte differentiation. The expression of C/EBPε in 32Dcl3 cells and FDCP1 cells expressing mutant G-CSF receptors was examined and it was found that G-CSF up-regulates C/EBPε. The signal for this expression required the region containing the first tyrosine residue of G-CSF receptor. Dominant-negative signal transducers and activators of transcription 3 blocked G-CSF–induced granulocytic differentiation in 32D cells but did not block induction of C/EBPε, indicating that these proteins work in different pathways. It was also found that overexpression of C/EBPε greatly facilitated granulocytic differentiation by G-CSF and, surprisingly, that expression of C/EBPε alone was sufficient to make cells differentiate into morphologically and functionally mature granulocytes. Overexpression of c-myc inhibits differentiation of hematopoietic cells, but the molecular mechanisms of this inhibition are not fully understood. In 32Dcl3 cells overexpressing c-myc that do not differentiate by means of G-CSF, induction of C/EBPε is completely abrogated. Ectopic expression of C/EBPε in these cells induced features of differentiation, including changes in nuclear morphologic characteristics and the appearance of granules. These data show that C/EBPε constitutes a rate-limiting step in G-CSF–regulated granulocyte differentiation and that c-myc antagonizes G-CSF–induced myeloid differentiation, at least partly by suppressing induction of C/EBPε.

scholarly journals Upregulation of Interleukin 6 and Granulocyte Colony-Stimulating Factor Receptors by Transcription Factor CCAAT Enhancer Binding Protein α (C/EBPα) Is Critical for Granulopoiesis

1998 ◽  
Vol 188 (6) ◽  
pp. 1173-1184 ◽  
Author(s):  
Pu Zhang ◽  
Atsushi Iwama ◽  
Milton W. Datta ◽  
Gretchen J. Darlington ◽  
Daniel C. Link ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Target Genes ◽  
Binding Protein ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Stimulating Factor ◽  
Deficient Mice

Cytokines stimulate granulopoiesis through signaling via receptors whose expression is controlled by lineage-specific transcription factors. Previously, we demonstrated that granulocyte colony-stimulating factor (G-CSF) receptor mRNA was undetectable and granulocyte maturation blocked in CCAAT enhancer binding protein α (C/EBPα)-deficient mice. This phenotype is distinct from that of G-CSF receptor−/− mice, suggesting that other genes are likely to be adversely affected by loss of C/EBPα. Here we demonstrate loss of interleukin 6 (IL-6) receptor and IL-6–responsive colony-forming units (CFU-IL6) in C/EBPα−/− mice. The observed failure of granulopoiesis could be rescued by the addition of soluble IL-6 receptor and IL-6 or by retroviral transduction of G-CSF receptors, demonstrating that loss of both of these receptors contributes to the absolute block in granulocyte maturation observed in C/EBPα-deficient hematopoietic cells. The results of these and other studies suggest that additional C/EBPα target genes, possibly other cytokine receptors, are also important for the block in granulocyte differentiation observed in vivo in C/EBPα-deficient mice.

scholarly journals A Truncated Granulocyte Colony-stimulating Factor Receptor (G-CSFR) Inhibits Apoptosis Induced by Neutrophil Elastase G185R Mutant

2017 ◽  
Vol 292 (8) ◽  
pp. 3496-3505 ◽  
Author(s):  
Yaling Qiu ◽  
Yangyang Zhang ◽  
Nan Hu ◽  
Fan Dong
Keyword(s):  
Unfolded Protein Response ◽  
Neutrophil Elastase ◽  
De Novo ◽  
Precursor Cells ◽  
Dominant Negative ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Unfolded Protein ◽  
Protein Response ◽  
Stimulating Factor

Mutations in ELANE encoding neutrophil elastase (NE) have been identified in the majority of patients with severe congenital neutropenia (SCN). The NE mutants have been shown to activate unfolded protein response and induce premature apoptosis in myeloid cells. Patients with SCN are predisposed to acute myeloid leukemia (AML), and progression from SCN to AML is accompanied by mutations in CSF3R encoding the granulocyte colony-stimulating factor receptor (G-CSFR) in ∼80% of patients. The mutations result in the expression of C-terminally truncated G-CSFRs that promote strong cell proliferation and survival. It is unknown why the CSF3R mutations, which are rare in de novo AML, are so prevalent in SCN/AML. We show here that a G-CSFR mutant, d715, derived from an SCN patient inhibited G-CSF-induced expression of NE in a dominant negative manner. Furthermore, G-CSFR d715 suppressed unfolded protein response and apoptosis induced by an SCN-derived NE mutant, which was associated with sustained activation of AKT and STAT5, and augmented expression of BCL-XL. Thus, the truncated G-CSFRs associated with SCN/AML may protect myeloid precursor cells from apoptosis induced by the NE mutants. We propose that acquisition of CSF3R mutations may represent a mechanism by which myeloid precursor cells carrying the ELANE mutations evade the proapoptotic activity of the NE mutants in SCN patients.

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