Expression of the basal cell adhesion molecule (B-CAM) in normal and diseased human skin

The basal cell adhesion molecule (B-CAM) is a 90-kD cell surface glycoprote in with a characteristic immunoglobulin domain structure. The pattern of B- CAM expression in cultured cells suggests that the molecule is associated w ith a substrate-adherent growth pattern in some lineages. We investigated t he expression of B-CAM in normal and diseased human epidermis by means of i mmunohistochemistry employing a single batch of high-titer mouse monoclonal antibody G253. Snap-frozen biopsy material from normal skin (n=8), psolias is (n=5), contact dermatitis (n=6). basal cell carcinoma (n=5) and fetal sk in (n=6) was studied. In normal human skin. B-CAM was found in varying degr ees throughout the epidermis with a preference for suprabasal expression, h air follicles were regularly of a B-CAM-positive phenotype. There were no q ualitative differences with regard to the B-CAM expression pattern in norma l skin ill comparison to psoriasis and contact dermatitis. In contrast, fet al skin (15th to 18th week of gestation) was characterized by B-CAM-positiv e cells in the basal layer of the epidermis as well as in the outer root sh eath of hair follicles. Basal cell carcinomas also regularly expressed high levels of B-CAM. A strong B-CAM-positive phenotype can be found in the out er root sheath of air follicles of adult and fetal human skin as well as in fetal basal kerarinocytes.