RESUMEN

Mutations in the Adenomatous Polyposis Coli (APC) tumor suppressor gene or the beta-catenin gene are present in most colon cancers and less frequently in other tumor types. In this study, we screened 24 human breast cancer cell lines and three immortalized human breast epithelial cell lines for alterations in beta- and gamma-catenin and APC by western blotting, protein truncation assay and DNA sequence analysis. In one cell line (DU 4475), an APC mutation was identified (E1577stop) that resulted in expression of truncated APC. This mutation was associated with elevated cytosolic beta-catenin levels, probably due to loss of APC function, as in colon cancers. No mutations were found in exon 3 of the beta- or gamma-catenin genes. We conclude that APC mutations and beta-catenin upregulation may occur with low frequency in human breast cancer cells.

Asunto(s)

Neoplasias de la Mama/genética , Proteínas del Citoesqueleto/genética , Genes APC/genética , Transactivadores , Proteína de la Poliposis Adenomatosa del Colon , Western Blotting , Mama/citología , Neoplasias de la Mama/metabolismo , Línea Celular Transformada , Proteínas del Citoesqueleto/metabolismo , Análisis Mutacional de ADN , Desmoplaquinas , Humanos , Mutación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , beta Catenina , gamma Catenina