Immunohistochemical localization of keratin in experimental carcinoma of the mouse submandibular gland

Abstract

An immunohistochemical survey of the distribution of keratin was studied in chemically induced carcinomas of the submandibular glands of mice. Initial signs of premalignant changes were degranulation of granular convoluted tubule cells and deposition of keratin protein in small limited areas of the degranulated cells. There was a gradual increase in the area showing keratin staining in altered tubule cells. Duct-like and cystic structures stained intensely for keratin, as did squamous metaplastic epithelial cells. Induced carcinomas were variably keratinized. Basal layers of cells of squamous-cell carcinomas displayed weak keratin staining, and spinous tumor cells and parakeratotic tumor cells showed somewhat increased levels of keratin staining. Some desquamated keratotic tumor cells stained intensely for keratin. Just as the localization of epidermal and nerve growth factors and lectin-binding histochemistry have been used in studying tumorigenesis in the mouse submandibular gland, immunohistochemically detected keratin proved to be a useful marker of tumor cells of ductal segment origin.