COMPARISON OF INTEGRIN, CADHERIN, AND CATENIN EXPRESSION IN SQUAMOUS-CELL CARCINOMAS OF THE ORAL CAVITY

In addition to their role in maintenance of tissue integrity, cell adh esion molecules regulate the growth and differentiation of stratified squamous epithelia, Reduced expression of E-cadherin and the alpha(2)b eta(1), alpha(3)beta(1), and alpha(6)beta(4) integrins is already repo rted to correlate with poor histological differentiation in oral squam ous cell carcinomas. However, it is not clear how closely cadherin and integrin loss are related in any given tumour, nor whether cadherin l oss is correlated with changes in expression of the cytoplasmic regula tory proteins known as catenins, Double-label immunofluorescence has b een used to stain a panel of 22 oral squamous cell carcinomas with ant ibodies to ten proteins, including E and P-cadherin, the major keratin ocyte integrin subunits, and alpha-, beta- and gamma-catenin, Overall, E-cadherin expression and integrin expression correlated well with tu mour grade, while P-cadherin staining was more variable. All tumours, regardless of differentiation status, showed reduced staining for at l east two of the catenins, implying that the adhesive function of E- an d P-cadherin could be impaired even when cadherin expression is normal . It is concluded that in all squamous cell carcinomas, regardless of degree of histological differentiation, there is some perturbed expres sion of cell adhesion molecules and that integrin and E-cadherin loss are closely related. (C) 1998 John Wiley & Sons, Ltd.