Chronic inflammation and carcinogenesis caused by intestinal specific ablation of integrin alpha6 beta4

Inflammatory bowel diseases (IBD) in humans are characterized by chronic inflammation and gastrointestinal tissue damage, caused by a combination of genetic and environmental factors. It has been largely documented that IBD frequently lead to colorectal cancers (CRC). The identification of causative factors of IBD is thus essential to understand CRC progression and develop therapeutical approaches. Models have been described in which molecular alterations are combined with inflammatory treatments in order to recapitulate IBD-associated CRC. Here, we describe a mouse line, 6fl/fl Villin-Cre, in which inactivation of the gene encoding the integrin alpha-6 subunit (ITGA6) specifically in the intestinal mucosa results into chronic inflammation and intestinal carcinogenesis. In these mice, the loss of integrin alpha-6 beta-4, a receptor mediating the attachment of epithelial cells to laminins, leads to epithelial detachment, hyperplasia, chronic inflammation, rectal prolapses, and ultimately adenocarcinomas. Alterations of differentiation affecting mucus secreting (goblet) cells as well as changes in expression of essential intestinal transcription factors were detected. Thus alpha-6 beta-4 integrin is a key factor for the maintenance of intestinal integrity and its loss may represent a risk factor for tumor progression associated with IBD.

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De Arcangelis A, Hamade H, Alpy F, Normand S, Bruyère E, Lefebvre O, Méchine-Neuville A, Siebert S, Pfister V, Lepage P, Laquerriere P, Dembele D, Delanoye-Crespin A, Rodius S, Robine S, Kedinger M, Van Seuningen I, Simon-Assmann P, Chamaillard M, Labouesse M, Georges-Labouesse E