E-cadherin and its associated cytoplasmic proteins α, β, and γ- catenin and p120 protein play a crucial role in the maintenance of normal tissue architecture. Perturbation in any of these molecules results in loss of intercellular adhesion and cell transformation. In this study, we have used immunohistochemistry to localize E-cadherin, α-, β, and γ-catenin, and p120 in paraffin-embedded tissues from 60 patients with colonic polyps. Specimens consisted of 20 samples each from hyperplastic, inflammatory, and sporadic adenomatous polyps. Ten histologically normal colonic samples were also studied. Normal colonic epithelial cells showed strong E- cadherin/catenin/p120 immunostaining at the cell-cell junction. In 65% (13/20) of adenomatous polyps, β-catenin showed abnormal nuclear localization with increased expression and loss of membranous staining compared with the adjacent normal mucosa. In two cases (10%), γ-catenin was seen in the nuclei. Heterogeneous p120 immunoreactivity was observed in four cases (20%), of which two also showed β-catenin nuclear localization. Preserved membranous α-catenin staining was seen in all cases. E-cadherin was down-regulated in 6 of 20 (30%) adenomas with loss of cell surface staining in 3 cases. All hyperplastic and 40% (8/20) of inflammatory polyps showed weak E-cadherin expression on the surface epithelium. Similar changes in p120 expression were seen in all hyperplastic and 20% (4/20) of inflammatory polyps. There were no concomitant changes in α-, β-, or γ- catenin expression. These results indicate that changes in catenin expression and cellular localization occur early in dysplastic colonic lesions.
|Number of pages||8|
|Journal||American Journal of Pathology|
|Publication status||Published - Jun 16 1997|
ASJC Scopus subject areas
- Pathology and Forensic Medicine