Constitutive expression of RbAp46 induces epithelial-mesenchymal transition in mammary epithelial cells

Background: Epithelial-mesenchymal transition (EMT) is a component of several morphogenetic and organogenetic processes during embryonic development. EMT is a strictly regulated process and its aberrant regulation may contribute to cancer progression and metastasis. The retinoblastoma suppressor (Rb)-associated protein 46 (RbAp46) is a component of the histone-modifying and -remodeling complexes. Materials and Methods: Western blot and immunofluorescent assays with epithelial and mesenchymal markers and cell migration and invasion assays were employed. Results: Mammary epithelial cells, MCF10AT3B, that express recombinant RbAp46 exhibited an EMT associated with the down-regulation of epithelial markers and up-regulation of mesenchymal markers, as well as an increased migration and invasion phenotype. Conclusion: Rbap46 may be an important player in EMT during embryonic development. Dysregulated RbAp46 expression may contribute to cancer progression and metastasis.