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

Background: Basigin is a glycosylated transmembrane protein belonging to the immunoglobulin superfamily and is thought to be associated with cell development and differentiation. We investigated the relation between Basigin expression and epidermal development in this study. Methods: Basigin expression was immunohistochemically investigated during organogenesis 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 follicular 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. Membranes of basal cells expressed more Basigin compared to other cell components. Basigin was not detectable in granular cells and telogen hair follicular cells. Sixteen of 30 BCCs were entirely negative for Basigin. However, cells at budding areas of tumor masses were positive in 14 of the 30 BCCs. Conclusions: These findings suggest that 1) Basigin is associated with epidermal proliferation and differentiation, 2) most parts of BCCs might be derived from early fetal epidermal basal cells, and 3) that a part, only the budding area of BCCs, has the characteristics of epithelial germ cells.