Expression of the adherens junction protein vinculin in human basal and squamous cell tumors: Relationship to invasiveness and metastatic potential

The acquisition of an invasive or metastatic phenotype in malignant neoplasms is often correlated with reduced cellular adhesiveness. We investigated the expression of the adhesion-associated cytoplasmic protein, vinculin, in normal and neoplastic human squamous epithelia, as well as in metastases of squamous cell carcinomas, and correlated the results with invasiveness and metastatic potential. Tissue samples from various tumors were examined, including basal cell carcinomas (BCG), keratoacanthomas, and squamous cell carcinomas (SCC). In addition, lymph node metastases from nine of the SCC were tested in this study. Our results indicate that most BCC, keratoacanthomas, and in situ SCC display strong positive staining for vinculin. The level of immunolabeling for vinculin and its pattern of distribution in the low malignant, nonmetastasizing lesions was similar to those observed in normal squamous epithelia. In contrast, in SCC, which are invasive and possess metastatic potential, as well as in their metastases, vinculin labeling was negative or poor, irrespective of their degree of differentiation. In conclusion, poor vinculin labeling in tumors of squamous epithelial origin examined here appears to be related to the metastatic potential of the tumor. Vinculin immunostaining of primary tumors originating in stratified squamous epithelia may thus be of value in helping to determine the metastatic potential of these neoplasms.