Keratinization and Tumor Promotion

Keratins are the major proteins synthesized by keratinocytes. They consist of a group of 10–20 different polypeptides in the molecular weight range of 48,000–67,000. Keratins associate in cells to form intermediate filaments, the major network of the keratinocyte cytoskeletal architecture. Keratins are produced in cells in a specific, sequential manner during epidermal stratification and the formation of the stratum corneum. Tumor promotion in mouse skin is associated with epidermal hyperplasia and aberrant cellular differentiation. This is accompanied by alterations in normal patterns of keratinization as revealed by high-resolution two-dimensional polyacrylamide gel electrophoresis. Changes in keratinization in mouse skin during tumor promotion may serve as useful markers for the development of neoplasia.