Abstract
Effects on administration of anti-tumor retinoid (Ro 10-9359, Etretinate) were studied in papilloma and squamous cell carcinoma experimentally induced from mice dorsal skin and hamster cheek pouch. Histochemical study of lectin binding and immunohistochemically detectable study of keratin, and microautoradiographic observation (3H-Etretinate, 3H-Vitamin A alcohol) were carried out.
Intercellular bridges in treated tumor epithelia were decreased and intercellular space were more spread. Tumor epithelial cells were separated from each other and they showed vacuolization at the area corresponding to granular and spinous cell layers, however, no PAS positive materials were contained there. Lectin binding and keratin staining were decreased in tumor epithelial cells which are affected by Etretinate. These were slightly positive or negative to lectin and keratin reactions in intercellular space and vacuolated tumor cells.
Microautoradiographic observation showed fine silver grains at the intercellular space and around the cell membrane in tumors, however, no deposits were in the cytoplasm of the tumor epithelial cells.
It was concluded that vitamin A derivative Etretinate may affect the intercellular spaces and cellular membrane of tumor epithelia, possibly cause changes of the permeabilities, sugar residues of cell membranes and cytoskeletal structures, and finally break down to cytoplasm of tumor cells.
