Regulation of alphaB-crystallin gene expression by the transcription factor Ets1 in breast cancer.
Breast Cancer Res Treat
; 119(1): 63-70, 2010 Jan.
Article
em En
| MEDLINE
| ID: mdl-19205872
ABSTRACT
Recent studies indicate that the small heat shock protein alphaB-crystallin is expressed in poor prognosis basal-like breast tumors and likely contributes to their aggressive phenotype. However, the mechanisms underlying the deregulated expression of alphaB-crystallin in basal-like tumors are poorly understood. Using a bioinformatics approach, we identified a putative DNA binding motif in the human alphaB-crystallin promoter for the proto-oncogene Ets1, a member of the ETS transcription factor family that bind to DNA at palindromic ETS-binding sites (EBS). Here we demonstrate that ectopic expression of Ets1 activates the alphaB-crystallin promoter by an EBS-dependent mechanism and increases alphaB-crystallin protein levels, while silencing Ets1 reduces alphaB-crystallin promoter activity and protein levels. Chromatin immunoprecipitation analyses showed that endogenous Ets1 binds to the alphaB-crystallin promoter in basal-like breast cancer cells in vivo. Interrogation of publically available gene expression data revealed that Ets1 is expressed in human basal-like breast tumors and is associated with poor survival. Collectively, our results point to a previously unrecognized link between the oncogenic transcription factor Ets1 and alphaB-crystallin in basal-like breast cancer.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Mama
/
Regulação Neoplásica da Expressão Gênica
/
Cadeia B de alfa-Cristalina
/
Proteína Proto-Oncogênica c-ets-1
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Female
/
Humans
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article