The epithelial cell adhesion molecule (Ep-CAM) as a morphoregulatory molecule is a tool in surgical pathology

Abstract

Cell adhesion receptors (CAMs) are actively involved in regulating various cell processes, including growth, differentiation, and cell death. Therefore, CAMs represent a large group of morphoregulating molecules, mediating cross-talk between cells and of cells with their environment. From this perspective, CAMs do contribute to cells and tissue organization, and in diseased tissue, to the disease development and biological characteristics. Therefore, observed changes in expression patterns of adhesion molecules may contribute to establish a diagnosis. A distinct shift in expression patterns in neoplastic epithelium has been described, for example for cadherins, integrins, and CD44. A relatively novel cell CAM, Ep-CAM, was first reported to be a pan-carcinoma antigen, although it is rather a marker of epithelial lineage. Several antibodies directed to Ep-CAM have been generated, and many epithelial tissues and their neoplastic appendages have been studied. This article outlines the results of these studies. Based on the results of these studies, we conclude that Ep-CAM immunohistochemistry can be a useful tool in the diagnosis of disturbed epithelial tissues.

Figure 1.

Schematic composition of Ep-CAM. SP, signal peptide; EGF, EGF-like domain; TM, transmembrane. The numbers indicate the amino acid residues that mark the regions in the molecule.

Figure 2.

Immunofluorescent double staining for Ep-CAM (red) and squamous differentiation marker cytokeratin 13 (green) in uterine cervix, stage CIN 1 (A), and stage 2 (B). The area where Ep-CAM is expressed is larger in CIN 2 as compared to CIN 1. For details see text and Litvinov and colleagues.