Abstract
BACKGROUND: Studies have suggested that in ulcerative colitis (UC), intercellular adhesion molecule-1 (ICAM-1) is involved in migration of leukocytes toward the colonic epithelium. A suitable in vitro model of chronic colonic inflammation does not exist, and the role of the epithelium is based on monolayers of cancer cells. Conflicting results exist on epithelial ICAM-1 expression, and the aim of this study was to compare the expression in various models of colonic epithelium.
MATERIALS AND METHODS: Colonic biopsies from four UC patients and four controls were examined by cryoimmuno-electron microscopy using ICAM-1-antibodies. In four other controls, the epithelium was isolated from colonic biopsies, embedded in collagen, and evaluated similarly. Isolated crypts and cultured cancer cells were stimulated with interferon-gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha).
RESULTS: ICAM-1 was not expressed in the biopsies. In contrast, HT29 cells and the collagen-embedded crypts expressed ICAM-1 on the apical membranes proximal to the junctional complexes when stimulated with IFN-gamma or TNF-alpha in a dose-related manner.
CONCLUSIONS: ICAM-1 is not expressed on colonic epithelium in vivo. However, both colonocytes and HT29 cells were capable of expressing ICAM-1 on their apical membranes in response to supraphysiologic cytokine concentrations. These observations question the justification of extrapolating observations from colon cancer cell lines to in vivo inflammatory conditions.
Original language | English |
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Journal | Virchows Archiv |
Volume | 443 |
Issue number | 6 |
Pages (from-to) | 774-81 |
Number of pages | 8 |
ISSN | 0945-6317 |
DOIs | |
Publication status | Published - Dec 2003 |
Keywords
- Adult
- Colitis, Ulcerative
- Colon
- Colonic Neoplasms
- Female
- HT29 Cells
- Humans
- Intercellular Adhesion Molecule-1
- Interferon-gamma
- Intestinal Mucosa
- Male
- Microscopy, Electron
- Tumor Necrosis Factor-alpha
- Journal Article
- Research Support, Non-U.S. Gov't