Basal-cell adhesion molecule (B-CAM) is induced in epithelial skin tumors and inflammatory epidermis, and is expressed at cell-cell and cell-substrate contact sites.
Basal-cell adhesion molecule (B-CAM) is a 90 kDa cell surface glycoprotein of the immunoglobulin superfamily that functions as a laminin-binding receptor. B-CAM is upregulated following malignant transformation of some cell types in vivo and in vitro, thus being a candidate molecule involved in tumor progression. As cutaneous distribution and function of B-CAM are largely unknown, we have studied its expression and regulation in normal and diseased human skin. In normal skin, B-CAM was expressed by endothelial cells of dermal blood vessels. In contrast, B-CAM was strongly upregulated within the tumor tissue of both malignant and benign epithelial skin tumors, including basal cell carcinomas, squamous cell carcinomas, keratoacanthomas, and common warts. Transformation-associated upregulation was confirmed in vitro, but normal keratinocytes also expressed B-CAM under culture conditions. Interestingly, the basal epidermal layer of normal-appearing skin surrounding the tumors also expressed B-CAM, and B-CAM were induced on the basal and apicolateral surfaces of basal keratinocytes in inflammatory skin disorders suggesting transformation-independent mechanisms of epidermal induction of the B-CAM. Immunoelectron microscopy studies of cultured transformed keratinocytes revealed that B-CAM was expressed at cell-cell and cell-substrate contact sites. Halting proliferation of transformed keratinocytes through cytostatic drugs resulted in decreased B-CAM synthesis. Likewise, inducing terminal differentiation in keratinocyte cultures by increasing the Ca(2+) concentration in the medium decreased B-CAM expression. In contrast, both ultraviolet A and B irradiation of cultured human keratinocytes resulted in significantly increased expression of the B-CAM. Overall, it appears that B-CAM expression in human skin is associated with activated states of keratinocytes, and that B-CAM may be involved in cell-cell adhesion or migration, in addition to its known function as a laminin receptor. J Invest Dermatol 115:1047-1053 2000
Schön
M
M
Department of Dermatology, University of Düsseldorf, Würzburg, Germany.
Klein
C E
CE
Hogenkamp
V
V
Kaufmann
R
R
Wienrich
B G
BG
Schön
M P
MP
D002277:Carcinoma / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D002450:Cell Communication / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D003872:Dermatitis / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D008188:Lutheran Blood-Group System; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D012878:Skin Neoplasms / Q000378:metabolism*; D014466:Ultraviolet Rays; D015854:Up-Regulation / Q000528:radiation effects
C090228:BCAM protein, human; D015815:Cell Adhesion Molecules; D008188:Lutheran Blood-Group System; D009363:Neoplasm Proteins