Expression of the cell-cell adhesion glycoprotein cell-CAM 120/80 in normal human tissues and tumors

Abstract

Polyclonal and monoclonal antibodies raised to the 80 kd glycoprotein component of the cell to cell adhesion molecule cell-CAM 120/80 were used to map its distribution immunohistochemically in normal human tissues and in benign and malignant tumors. Cell-CAM 120/80 was found in all normal epithelial tissues, but was not expressed on neural, lymphoid, smooth, striated and cardiac muscle, connective tissue, or the germ cells in either sex. The expression of this adhesion molecule was polarized in ductal and glandular epithelia and evenly circumferential in squamous and transitional epithelia. Some organs, such as the kidney, liver and endocrine glands, showed unique organ to tissue specific patterns. Maturation-dependent loss of cell-CAM 120/80 was noticed in superficial layers of squamous epithelium and the placenta. Benign epithelial tumors expressed cell-CAM 120/80 in a manner comparable with their tissue of origin. Malignant tumors expressed cell-CAM 120/80 either in a manner similar to the tissue of their origin or assumed a less polarized phenotype. Overall, the immunoreactivity in many malignant tumors appeared weaker and the polarization was less pronounced. Thus, cell-CAM 120/80 is a universal marker of human epithelial cells, but its mode of expression differs in various anatomic sites, and may be influenced by maturation or malignant transformation of cells.