The dioxin/aryl hydrocarbon receptor mediates downregulation of osteopontin gene expression in a mouse model of gastric tumourigenesis.
Oncogene
; 24(19): 3216-22, 2005 Apr 28.
Article
em En
| MEDLINE
| ID: mdl-15735673
ABSTRACT
The dioxin/aryl hydrocarbon receptor functions as a ligand-activated transcription factor regulating transcription of a battery of genes encoding primarily drug-metabolizing enzymes. Expression of a constitutively active mutant of the aryl hydrocarbon receptor (CA-AhR) in transgenic mice results in development of stomach tumours, correlating with increased mortality. We have used suppression subtractive hybridization techniques followed by macroarray analysis to elucidate which genes are differentially expressed during this process. In the glandular stomach of CA-AhR mice, we observed decreased mRNA expression of osteopontin (OPN), a noncollagenous protein of bone matrix that is also involved in several important functions including regulation of cytokine production, macrophage accumulation, cell motility and adhesion. Downregulated expression of OPN during tumour development was confirmed by RT-PCR and RNA blot analysis. Immunohistochemical analysis showed that this decrease was confined to the corpus region, correlating with the restricted localization of the tumours. Decreased OPN mRNA expression was also observed in other organs of CA-AhR mice. Taken together, these results show that OPN is negatively regulated by the dioxin receptor, and that downregulation of its expression correlates with development of stomach tumours in mice expressing a constitutively active mutant of dioxin receptor.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sialoglicoproteínas
/
Neoplasias Gástricas
/
Regulação para Baixo
/
Regulação Neoplásica da Expressão Gênica
/
Receptores de Hidrocarboneto Arílico
/
Hidrocarbonetos
/
Neoplasias Experimentais
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Oncogene
Assunto da revista:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Suécia