Differences of E-cadherin expression levels and patterns in human lung cancer.

Fifty-two lung carcinomas obtained at surgical resection were examined by immunofluorescence for their expression levels and patterns of the calcium-dependent intercellular adhesion molecule E-cadherin. In well-differentiated squamous cell and adenocarcinomas expression of E-cadherin was confined to the lateral cell border, similar to the expression level and pattern of normal lung tissue. The E-cadherin level was reduced and the expression pattern was spotty or diffuse in moderately and poorly differentiated squamous cell carcinomas and in small cell carcinomas of the lung. Also, most metastases resected had a reduced level and an altered pattern of E-cadherin expression. In contrast, no such correlation was found in adenocarcinomas of the lung. This indicates that different cellular mechanisms are responsible in the progression of squamous cell carcinomas versus adenocarcinomas of the lung.