Abnormal expression of the E-cadherin-catenin complex in dysplastic Barrett's oesophagus.

It is now accepted that altered E-cadherin-catenin complex expression in oesophageal cancer correlates with clinical and pathological parameters, while abnormal E-cadherin expression occurs early in Barrett's oesophagus. We evaluated immunohistochemically the expression and cellular localization of alpha-, beta-, and gamma-catenin, and E-cadherin in 5 dysplastic and 26 non-dysplastic cases of Barrett's oesophagus. Usually all three catenins were localized at the cell membrane, as was E-cadherin. A similar staining pattern for E-cadherin and the catenins was observed in all cases of non-dysplastic Barrett's syndrome. However, 60% (3/5) of cases with dysplasia showed loss of membranous beta-catenin staining and diffuse cytoplasmic distribution, with predominantly nuclear localization in two cases. Membranous staining and concomitant cytoplasmic localization of E-cadherin, alpha-catenin and gamma-catenin were seen in one case with abnormal beta-catenin immunoreactivity. Our results indicate that altered subcellular distribution of beta-catenin occurs frequently in dysplastic Barrett's oesophagus and possibly reflects the signalling function of this molecule.