Expression of Basigin in human fetal, infantile and adult skin and in basal cell carcinoma

Background: Basigin is a glycosylated transmembrane protein belonging to th e immunoglobulin superfamily and is thought to be associated with cell deve lopment and differentiation. We investigated the relation between Basigin e xpression and epidermal development in this study. Methods: Basigin expression was immunohistochemically investigated during o rganogenesis of human skin and in human basal cell carcinoma (BCC). Results: Human fetal skin showed negative staining at 10 weeks of gestation . At 20 weeks, the cytoplasm and membranes of adnexal germ and hair follicu lar cells were strongly positive, while epidermal basal cells showed weakly positive staining. After birth, basal cells, suprabasal cells, anagen hair follicular cells and eccrine glandular cells showed positive staining. Mem branes of basal cells expressed more Basigin compared to other cell compone nts. Basigin was not detectable in granular cells and telogen hair follicul ar cells. Sixteen of 30 BCCs were entirely negative for Basigin. However, c ells at budding areas of tumor masses were positive in 14 of the 30 BCCs. Conclusions: These findings suggest that 1) Basigin is associated with epid ermal proliferation and differentiation, 2) most parts of BCCs might be der ived from early fetal epidermal basal cells, and 3) that a part, only the b udding area of BCCs, has the characteristics of epithelial germ cells.