E-cadherin expression in primary and metastatic thoracic neoplasms and in Barrett's oesophagus.

Reduced expression of E-cadherin, a Ca(2+)-dependent cell adhesion molecule present in normal epithelium, has been associated with invasive and metastatic cancer. Immunohistochemistry was used in examining the relationship between E-cadherin expression and stage in 59 oesophageal and 52 lung cancers. Advanced-stage oesophageal cancers were associated with both reduced and disorganised E-cadherin expression (P < 0.01). Advanced-stage lung adenocarcinomas generally exhibited disorganised or reduced E-cadherin expression, but no statistical association between expression pattern and stage was found (P > 0.05). No differences in stage were seen between tumours with reduced or disorganised E-cadherin expression. Altered E-cadherin expression was detected in dysplastic, non-invasive Barrett's oesophagus. Importantly, high-level E-cadherin expression was detected in 17 of 17 lymph nodes containing metastatic cancer. E-cadherin mRNA expression was decreased in tumours with reduced protein expression, but not in tumours with disorganised expression. Expression of alpha-catenin mRNA, an E-cadherin-associated protein, was detected in tissues with altered E-cadherin protein expression. Reduced and disorganised expression of E-cadherin appear to be related to transcriptional and post-translational events respectively, and both appear to represent altered cell adhesion associated with invasion and metastasis in thoracic neoplasms.