TRANSFORMATION AND TUMOR PROGRESSION ARE FREQUENTLY ASSOCIATED WITH EXPRESSION OF THE ALPHA(3) BETA(1) HETERODIMER IN SOLID TUMORS/

The ability of tumor cells to interact with the extracellular matrix ( ECM) is functionally mediated by a variety of receptor molecules among which the integrins are a well-characterized family of mediators. In this study we have investigated immunohistochemically the in vivo expr ession of the alpha(3)/beta(1) promiscuous receptor for ECM constituen ts in a variety of human solid malignancies. Although the receptor app ears to undergo changes in distribution patterns, its expression is ma intained in a high percentage of primary (76%) and metastatic (82%) tu mors. Furthermore, the comparative immunohistochemical evaluation of a lpha(3)/beta(1) and its ligands, in a selected number of tumors of dif ferent histotypes, demonstrated that the expression of this integrin c orrelated with the presence of at least one ligand, either around nest s of neoplastic cells or at the epithelial-stromal interface. The high ly conserved expression of alpha(3)/beta(1) shown in this study sugges ts that this receptor may play a role in tumor growth at the primary a s well as the metastatic site. (C) 1994 Wiley-Liss, Inc.