Differences in the urea-extracted or fibrous proteins of mouse epidermis at various stages of malignant transformation.

Abstract

The urea-extractable proteins of normal and hyperplastic mouse epidermis, papilloma, and squamous-cell carcinoma were fractionated by gel filtration on Sepharose 4B to yield proteins which were excluded and retarded. The level of the proteins which were excluded decreased from normal epidermis through hyperplastic epidermis, papilloma, and carcinoma, whereas the retarded protein fractions increased proportionately. Ultra-centrifugation of these urea proteins resulted in gel and supernatant fractions, each of which accounted for approximately 50% of the total proteins for normal epidermis, papilloma, and carcinoma. The gel and supernatant fractions and the proteins which were excluded and retarded by Sepharose 4B were employed in immunodiffusion in agar against antisera or IgG fractions of antisera raised against the various urea proteins. These results showed that antigenic differences existed between the fibrous proteins of normal epidermis and papilloma or carcinoma, but the latter two tissues were antigenically similar with respect to these proteins.