Immunohistochemical localization of members of the transforming growth factor (TGF)-beta superfamily in normal human salivary glands and pleomorphic adenomas.
Although pleomorphic adenoma is the most common type of salivary gland epithelial tumor, it frequently contains "mesenchymal"-like components, including myxoid or chondroid tissues. We reported previously that chondroid tissue formation in pleomorphic adenoma was associated with overexpression of bone morphogenetic proteins (BMPs) by neoplastic myoepithelial cells. BMPs belong to the transforming growth factor (TGF)-beta superfamily, so we hypothesized that pleomorphic adenoma may express TGF-betas and that these molecules may regulate mesenchymal-like tissue formation. To evaluate this hypothesis, we immunohistochemically examined TGF-beta1, -beta2 and -beta3 expression and localization in normal salivary glands and in 43 cases of pleomorphic adenomas. There was no evidence of TGF-beta1 expression in normal salivary glands or pleomorphic adenomas. Signals for TGF-beta2 in the normal salivary glands were observed in the intercalated ducts, while in pleomorphic adenomas they were observed in the inner ductal cells of the tubulo-glandular structures. Signals for TGF-beta3 in the normal salivary glands were observed in mucous cells, whereas in pleomorphic adenomas they were observed in the solid nests of neoplastic myoepithelial cells, in the portion showing squamous metaplasia, and in the inner ductal cells of tubulo-glandular structures. TGF-betas induce ectopic cartilage formation in vivo, but chondroid tissues in pleomorphic adenomas showed only weak TGF-beta3 expression. TGF-beta may be related to differentiation of the inner ductal cells and the neoplastic myoepithelial cells. In conclusion, pleomorphic adenomas expressed TGF-beta2 and -beta3, which may be associated with differentiation of the inner ductal cells and neoplastic myoepithelial cells.
Kusafuka
K
K
Department of Pathology, Japanese Red Cross Medical Center, Tokyo.
Yamaguchi
A
A
Kayano
T
T
Takemura
T
T
D008949:Adenoma, Pleomorphic / Q000473:pathology*; D000906:Antibodies; D019485:Bone Morphogenetic Proteins / Q000032:analysis; D002356:Cartilage / Q000473:pathology; D002454:Cell Differentiation; D004396:Coloring Agents; D004847:Epithelial Cells / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008648:Mesoderm / Q000473:pathology; D008679:Metaplasia; D009092:Mucous Membrane / Q000473:pathology; D018987:Salivary Ducts / Q000473:pathology; D012468:Salivary Gland Neoplasms / Q000473:pathology*; D012469:Salivary Glands / Q000473:pathology*; D016212:Transforming Growth Factor beta / Q000032:analysis*; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D053782:Transforming Growth Factor beta3
D000906:Antibodies; D019485:Bone Morphogenetic Proteins; D004396:Coloring Agents; C508960:TGFB1 protein, human; C509041:TGFB2 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D053782:Transforming Growth Factor beta3