Specific keratins as molecular markers for neoplasms with a stratified epithelial origin.

The expression of specific keratin polypeptides in human neoplasms was investigated by the immunoblot technique using monoclonal anti-keratin antibodies. Mr 50,000 and 58,000 keratins, recognized by AE1 and AE3 antibodies, respectively, were detected only in carcinomas of stratified epithelial origin, but not in carcinomas derived from simple epithelia. No keratin was detected in nonepithelial tumors including melanoma, lymphoma, neurofibroma, and sarcoma. The results suggest that the Mr 50,000 and 58,000 keratins provide useful molecular markers for identifying neoplasms of stratified squamous epithelial origin.