Anti-Keratin Monoclonal Antibody Against Basal Cell Epithelioma Keratin: BKN-1

The study involved immunizing a BALB/c mouse with fibrous proteins extracted from basal cell epithelioma (BCE) to produce anti-keratin monoclonal antibodies using a hybridoma technique. The resulting monoclonal antibody, BKN-1, consistently stained the cytoplasm of tumor cells in 17 cases of BCE. In normal human skin, BKN-1 specifically reacted with basal cells in the epidermis, infundibular epithelium of hair follicles, follicular cells below the isthmus in anagen hair follicles, peripheral cells of sebaceous glands, and sweat gland cells. Immunoelectron microscopy located the reaction on tonofilaments in the cytoplasm, and immunoblot analysis showed BKN-1 staining a 56–56.5K band in BCE fibrous proteins or several bands in normal epidermal fibrous proteins. These findings suggested that keratin expression in BCE resembled that of the follicular epithelium below the isthmus portion.