Deutscher N, Bataille F, Hausmann M, Kiessling S, Muller-Newen G, Leeb SN, Herfarth H, Heinrich PC, Schölmerich J, Rogler G. Functional expression of the interleukin-11 receptor alpha-chain in normal colonic epithelium and colon cancer.
Int J Colorectal Dis 2006;
21:573-81. [PMID:
16292518 DOI:
10.1007/s00384-005-0055-8]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/22/2005] [Indexed: 02/04/2023]
Abstract
BACKGROUND
Interleukin-11 (IL-11) has been evaluated as an anti-inflammatory and mucosa-protective therapeutic agent in inflammatory bowel diseases (IBDs). Activity of IL-11 requires binding to the alpha receptor subunit (IL-11Ralpha) that provides ligand specificity. Recently, we showed that in the intestinal mucosa, IL-11Ralpha is mainly present on epithelial cells mediating antiapoptotic effects. The aim of this study was to investigate the expression profiling of IL-11Ralpha and its downstream signaling cascade in colonic adenoma and carcinoma.
MATERIALS AND METHODS
The expression of IL-11Ralpha in normal colonic mucosa, 11 colonic adenomas, and 10 carcinomas was analyzed by immunohistochemistry. In addition, IL-11Ralpha-expression and IL-11Ralpha-induced phosphorylation of signal transducer and activator of transcription (STAT)3 were investigated by Western blot analysis.
RESULTS
Immunohistochemistry revealed significant IL-11-Ralpha expression in epithelial cells of normal colonic mucosa. In contrast, the expression of IL-11-Ralpha in colon adenomas and carcinomas was either absent or only detectable in very few scattered epithelial cells. Densitometric analysis of Western blots confirmed these results, showing a decrease of IL-11Ralpha-protein in cells isolated from adenomas or carcinomas. Reduced STAT3-phosphorylation in carcinoma cells indicated functional consequences of decreased IL-11Ralpha-protein expression on signal transduction.
CONCLUSION
This study demonstrates a decrease of IL-11-Ralpha-protein expression in epithelial cells isolated from colon carcinomas and adenomas compared to normal colonic mucosa and a reduced STAT3 signaling. Because of reduced binding and signal transduction, it is unlikely that therapeutically administered IL-11 would contribute to colorectal carcinoma induction and growth.
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