Brown JB, Lee G, Managlia E, Grimm GR, Dirisina R, Goretsky T, Cheresh P, Blatner NR, Khazaie K, Yang GY, Li L, Barrett TA. Mesalamine inhibits epithelial beta-catenin activation in chronic ulcerative colitis.
Gastroenterology 2010;
138:595-605, 605.e1-3. [PMID:
19879273 PMCID:
PMC2819654 DOI:
10.1053/j.gastro.2009.10.038]
[Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 09/21/2009] [Accepted: 10/20/2009] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS
Mesalamine is a mainstay therapeutic agent in chronic ulcerative colitis (CUC) in which condition it reverses crypt architectural changes and reduces colitis-associated cancer (CAC). The present study addressed the possibility that mesalamine reduces beta-catenin-associated progenitor cell activation, Akt-phosphorylated beta-catenin(Ser552) (P-beta-catenin), and colitis-induced dysplasia (CID).
METHODS
Effects of mesalamine on P-beta-catenin staining and function were assessed by immunohistochemistry and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) in biopsy specimens of CUC in mild or "refractory" severe mucosal inflammation. Effects of mesalamine on epithelial proliferation and activation of Akt and beta-catenin were assessed in interleukin (IL)-10(-/-) colitis and CID by immunohistochemistry and Western blotting. Dysplasia was assessed by counting the number and lengths of lesions per colon.
RESULTS
Data from IL-10(-/-) and human colitis samples show that mesalamine reduced Akt activation and P-beta-catenin levels in the middle and upper crypt. Reductions in P-beta-catenin in CUC biopsy specimens with severe inflammation suggested that mesalamine reduced P-beta-catenin levels in tissue refractory to mesalamine's anti-inflammatory effects. In IL-10(-/-) mice, mesalamine reduced CID concordant with inhibition of crypt Akt and beta-catenin signaling.
CONCLUSIONS
The results are consistent with the model that mesalamine contributes to chemoprevention in CAC by reducing beta-catenin signaling within intestinal progenitors.
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