ERß splice variant expression in four large cohorts of human breast cancer patient tumors.
Breast Cancer Res Treat
; 146(3): 657-67, 2014 Aug.
Article
en En
| MEDLINE
| ID: mdl-25007965
Though the role of Estrogen Receptor (ER)α in breast cancer has been studied extensively, there is little consensus about the role of alternative ER isoform ERß in breast cancer biology. ERß has significant sequence homology to ERα but is located on a different chromosome and maintains both overlapping and unique functional attributes. Five variants exist, resulting from alternative splicing of the C-terminal region of ERß. The relevance of ERß variants in breast cancer outcomes and response to therapy is difficult to assess because of conflicting reports in the literature, likely due to variable methods used to assess ERß in patient tumors. Here, we quantitatively assess expression of ERß splice variants on over 2,000 breast cancer patient samples. Antibodies against ERß variants were validated for staining specificity in cell lines by siRNA knockdown of ESR2 and staining reproducibility on formalin-fixed paraffin-embedded tissue by quantitative immunofluorescence (QIF) using AQUA technology. We found antibodies against splice variants ERß1 and ERß5, but not ERß2/cx, which were sensitive, specific, and reproducible. QIF staining of validated antibodies showed both ERß1 and ERß5 QIF scores, which have a normal (bell shaped) distribution on most cohorts assessed, and their expression is significantly associated with each other. Extensive survival analyses show that ERß1 is not a prognostic or predictive biomarker for breast cancer. ERß5 appears to be a context-dependent marker of worse outcome in HER2-positive and triple-negative patients, suggesting an unknown biological function in the absence of ERα.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Pronóstico
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Isoformas de Proteínas
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Receptor beta de Estrógeno
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Neoplasias de la Mama Triple Negativas
Tipo de estudio:
Etiology_studies
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Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Límite:
Adult
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Aged
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Female
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Humans
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Middle aged
Idioma:
En
Revista:
Breast Cancer Res Treat
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Países Bajos