To elucidate the role of keratin modification in tumor promotion, we investigated the keratin polypeptide patterns of mouse epidermis, papillomas, and carcinomas throughout an initiation-promotion experiment. The epidermal keratin modifications induced by repetitive 12-O-tetradecanoylphorbol-13-acetate treatments in both initiated and noninitiated mouse skin were essentially identical to those observed with a single 12-O-tetradecanoylphorbol-l 3-acetate application. These changes were even more pronounced in epidermal papillomas. In addition, the keratins of the papillomas displayed greater charge heterogeneity, particularly among the high-molecular-weight keratins (Mr 60,000 to 62,000). As the experiment progressed, there appeared to be a selective loss of one group of high-molecular-weight keratins (Mr 62,000) in some of the papillomas. Interestingly, the carcinomas that appeared at this time had significant reduction in both groups of high-molecular-weight keratins. In fact, the keratin profiles of carcinomas were very similar to the patterns observed in basal cells after a single 12-0-tetradecanoylphorbol-13-acetate treatment of adult epidermis. This may indicate that the program of keratin expression of a carcinoma becomes permanently fixed at a basal cell pattern. Changes in keratin patterns may serve as a biochemical marker of malignant progression in mouse epidermis.
|Original language||English (US)|
|Number of pages||6|
|State||Published - Oct 1 1982|
ASJC Scopus subject areas
- Cancer Research