Simultaneous appearance of keratin modifications and gamma-glutamyltransferase activity as indicators of tumor progression in mouse skin papillomas
Klein-Szanto, A.J.; Nelson, K.G.; Shah, Y.; Slaga, T.J.
Journal of the National Cancer Institute 70(1): 161-168
1983
ISSN/ISBN: 0027-8874 PMID: 6185712 Document Number: 215716
gamma-Glutamyltransferase (GGT), an enzyme not found in normal adult epidermis, was detected in most skin papillomas larger than 13 mm in diameter and in all squamous carcinomas induced by 7,12-dimethylbenzanthracene initiation and 12-O-tetradecanoylphorbol 13-acetate promotion in noninbred Sencar mice. Furthermore, these GGT-positive lesions were also characterized by a marked decrease or absence of high-molecular-weight components of epidermal keratin. Since these characteristics are common to both carcinomas and large papillomas but are practically undetectable in normal epidermis and small papillomas, GGT activity and lack of high-molecular-weight keratin components seem to be good indicators of tumor progression, i.e., from papilloma to squamous carcinoma.