Abstract
Primary murine fetal hemopoietic cells were transformed with a fusion protein consisting of the ligand-binding domain of the estrogen receptor and a carboxyl-terminally truncated c-Myb protein (ERMYB). The ERMYB-transformed hemopoietic cells exhibit an immature myeloid phenotype when grown in the presence of β-estradiol. Upon removal of β-estradiol, the ERMYB cells display increased adherence, decreased clonogenicity and differentiate to cells exhibiting granulocyte or macrophage morphology. The expression of the c-myc, c-kit, cdc2 and bcl-2 genes, which are putatively regulated by Myb, was investigated in ERMYB cells grown in the presence or absence of β-estradiol. Neither c-myc nor cdc2 expression was down-regulated after removal of β-estradiol demonstrating that differentiation is not a consequence of decreased transactivation of these genes by ERMYB. While bcl-2 expression was reduced by 50% in ERMYB cells grown in the absence of β-estradiol, there was no increase in DNA laddering, suggesting that Myb was not protecting ERMYB cells from apoptosis. In contrast, a substantial (200-fold) decrease in c-kit mRNA level was observed following differentiation of ERMYB cells, and c-kit mRNA could be partially re-induced by the re-addition of β-estradiol. Furthermore, a reporter construct containing the c-kit promoter was activated when cotransfected with a Myb expression vector, providing further evidence of a role for Myb in the regulation of c-kit.
| Original language | English |
|---|---|
| Pages (from-to) | 2885-2898 |
| Number of pages | 14 |
| Journal | Oncogene |
| Volume | 15 |
| Issue number | 24 |
| Publication status | Published - 1997 |
| Externally published | Yes |
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Keywords
- Apoptosis
- Apoptosis target genes
- Bcl-2
- Differentiation
- Myb
ASJC Scopus subject areas
- Molecular Biology
- Cancer Research
- Genetics
Cite this
Inactivation of a c-Myb/estrogen receptor fusion protein in transformed primary cells leads to granulocyte/macrophage differentiation and down regulation of c-kit but not c-myc cdc2. / Hogg, Annette; Schirm, Sabine; Nakagoshi, Hideki; Bartley, Paul; Ishii, Shunsuke; Bishop, J. Michael; Gonda, Thomas J.
In: Oncogene, Vol. 15, No. 24, 1997, p. 2885-2898.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Inactivation of a c-Myb/estrogen receptor fusion protein in transformed primary cells leads to granulocyte/macrophage differentiation and down regulation of c-kit but not c-myc cdc2
AU - Hogg, Annette
AU - Schirm, Sabine
AU - Nakagoshi, Hideki
AU - Bartley, Paul
AU - Ishii, Shunsuke
AU - Bishop, J. Michael
AU - Gonda, Thomas J.
PY - 1997
Y1 - 1997
N2 - Primary murine fetal hemopoietic cells were transformed with a fusion protein consisting of the ligand-binding domain of the estrogen receptor and a carboxyl-terminally truncated c-Myb protein (ERMYB). The ERMYB-transformed hemopoietic cells exhibit an immature myeloid phenotype when grown in the presence of β-estradiol. Upon removal of β-estradiol, the ERMYB cells display increased adherence, decreased clonogenicity and differentiate to cells exhibiting granulocyte or macrophage morphology. The expression of the c-myc, c-kit, cdc2 and bcl-2 genes, which are putatively regulated by Myb, was investigated in ERMYB cells grown in the presence or absence of β-estradiol. Neither c-myc nor cdc2 expression was down-regulated after removal of β-estradiol demonstrating that differentiation is not a consequence of decreased transactivation of these genes by ERMYB. While bcl-2 expression was reduced by 50% in ERMYB cells grown in the absence of β-estradiol, there was no increase in DNA laddering, suggesting that Myb was not protecting ERMYB cells from apoptosis. In contrast, a substantial (200-fold) decrease in c-kit mRNA level was observed following differentiation of ERMYB cells, and c-kit mRNA could be partially re-induced by the re-addition of β-estradiol. Furthermore, a reporter construct containing the c-kit promoter was activated when cotransfected with a Myb expression vector, providing further evidence of a role for Myb in the regulation of c-kit.
AB - Primary murine fetal hemopoietic cells were transformed with a fusion protein consisting of the ligand-binding domain of the estrogen receptor and a carboxyl-terminally truncated c-Myb protein (ERMYB). The ERMYB-transformed hemopoietic cells exhibit an immature myeloid phenotype when grown in the presence of β-estradiol. Upon removal of β-estradiol, the ERMYB cells display increased adherence, decreased clonogenicity and differentiate to cells exhibiting granulocyte or macrophage morphology. The expression of the c-myc, c-kit, cdc2 and bcl-2 genes, which are putatively regulated by Myb, was investigated in ERMYB cells grown in the presence or absence of β-estradiol. Neither c-myc nor cdc2 expression was down-regulated after removal of β-estradiol demonstrating that differentiation is not a consequence of decreased transactivation of these genes by ERMYB. While bcl-2 expression was reduced by 50% in ERMYB cells grown in the absence of β-estradiol, there was no increase in DNA laddering, suggesting that Myb was not protecting ERMYB cells from apoptosis. In contrast, a substantial (200-fold) decrease in c-kit mRNA level was observed following differentiation of ERMYB cells, and c-kit mRNA could be partially re-induced by the re-addition of β-estradiol. Furthermore, a reporter construct containing the c-kit promoter was activated when cotransfected with a Myb expression vector, providing further evidence of a role for Myb in the regulation of c-kit.
KW - Apoptosis
KW - Apoptosis target genes
KW - Bcl-2
KW - Differentiation
KW - Myb
UR - http://www.scopus.com/inward/record.url?scp=0031455764&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031455764&partnerID=8YFLogxK
M3 - Article
VL - 15
SP - 2885
EP - 2898
JO - Oncogene
JF - Oncogene
SN - 0950-9232
IS - 24
ER -