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Bcl9 and Pygo synergise downstream of Apc to effect intestinal neoplasia in FAP mouse models

Bcl9 and Pygo are Wnt enhanceosome components that effect β-catenin-dependent transcription. Whether they mediate β-catenin-dependent neoplasia is unclear. Here we assess their roles in intestinal tumourigenesis initiated by Apc loss-of-function (Apc(Min)), or by Apc(1322T) encoding a partially-func...

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Detalles Bibliográficos
Autores principales: Mieszczanek, Juliusz, van Tienen, Laurens M., Ibrahim, Ashraf E. K., Winton, Douglas J., Bienz, Mariann
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6374407/
https://www.ncbi.nlm.nih.gov/pubmed/30760710
http://dx.doi.org/10.1038/s41467-018-08164-z
Descripción
Sumario:Bcl9 and Pygo are Wnt enhanceosome components that effect β-catenin-dependent transcription. Whether they mediate β-catenin-dependent neoplasia is unclear. Here we assess their roles in intestinal tumourigenesis initiated by Apc loss-of-function (Apc(Min)), or by Apc(1322T) encoding a partially-functional Apc truncation commonly found in colorectal carcinomas. Intestinal deletion of Bcl9 extends disease-free survival in both models, and essentially cures Apc(1322T) mice of their neoplasia. Loss-of-Bcl9 synergises with loss-of-Pygo to shift gene expression within Apc-mutant adenomas from stem cell-like to differentiation along Notch-regulated secretory lineages. Bcl9 loss also promotes tumour retention in Apc(Min) mice, apparently via relocating nuclear β-catenin to the cell surface, but this undesirable effect is not seen in Apc(1322T) mice whose Apc truncation retains partial function in regulating β-catenin. Our results demonstrate a key role of the Wnt enhanceosome in β-catenin-dependent intestinal tumourigenesis and reveal the potential of BCL9 as a therapeutic target during early stages of colorectal cancer.