[Immunohistopathological properties of cytoskeletal proteins and extracellular matrix components in pleomorphic adenomas of salivary glands].

Twenty-five pleomorphic adenomas and 10 normal salivary glands were immunohistochemically studied with respect to cytoskeletal proteins and extracellular matrix components to observe the relationship between these components and the differentiation of tumor cells in pleomorphic adenomas. For immunohistochemical observation, keratin (AE1), vimentin (V9), alpha-smooth muscle actin (1A4) and type IV collagen (JK-199) were studied by means of monoclonal antibodies, and laminin (LM) and fibronectin (FN) were analysed with polyclonal antibodies. AE1 was localized in inner tubular cells, and 1A4 was identified in spindle and leiomyomatous cells. These observations may provide evidence of differentiation into ductal epithelia and myoepithelial cells, respectively. Positive staining for V9 in cuboidal cells suggests dedifferentiation. The extracellular matrix components, JK-199, LM and FN, were localized in surrounding areas of cells stained by V9 and/or 1A4. This suggests that expression of these cytoskeletal proteins and extracellular matrix components may affect each other, and ther by contribute to cellular differentiation and production of extracellular matrix.