title: Co-localization of chondromodulin-I (ChM-I) and bone morphogenetic protein-6 (BMP-6) in myoepithelial cells of canine mammary tumors.
abstract: To compare the roles of chondromodulin-I (ChM-I) and bone morphogenetic protein-6 (BMP-6) in ectopic mesenchymal tissue formation in canine mammary gland tumors, 33 tumors and 2 normal mammary glands were examined. Immunohistochemical analysis revealed co-expression of ChM-I and BMP-6 in canine mammary tumors. In mixed tumors, newly formed woven bone with ossified cartilage matrix was observed in 4/9 cases. The osteoblasts lining the woven bone showed moderate immunoreactivity to ChM-I and BMP-6. Almost all chondrocytes and proliferative myoepithelial cells within the basement membrane showed intense immunoreactivity to both, and the myoepithelial cells adjacent to the mature cartilage showed the most intense immunoreactivity. The immunoreactivity to ChM-I and BMP-6 of the interstitial myoepithelial cells in the myxomatous stroma varied in each focus of mixed tumors. Similar findings were found in complex adenomas. In simple adenomas, hyperplasic myoepithelial cells within the basement membrane showed moderate immunoreactivity to both markers. Western blot analysis detected a 25 kDa band of ChM-I in fresh tissue samples from three mixed tumors. Our results support the hypothesis that proliferating myoepithelial cells with ChM-I and BMP-6 expression play important roles in mesenchymal metaplasia in canine mammary tumors.
authors.affiliation: Department of Pathogenetic and Preventive Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawabata
authors.forename: Kumiko
authors.initials: K
authors.lastname: Okano
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Uchida
authors.forename: Ryoji
authors.initials: R
authors.lastname: Yamaguchi
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Hayashi
authors.forename: Susumu
authors.initials: S
authors.lastname: Tateyama
mesh_terms: D000818:Animals; D015153:Blotting, Western / Q000662:veterinary; D055418:Bone Morphogenetic Protein 6; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D002828:Choristoma / Q000378:metabolism / Q000662:veterinary*; D004283:Dog Diseases / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D004847:Epithelial Cells / Q000378:metabolism; D007150:Immunohistochemistry / Q000662:veterinary; D015674:Mammary Neoplasms, Animal / Q000378:metabolism* / Q000473:pathology; D008679:Metaplasia / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*
chemical_list: D055418:Bone Morphogenetic Protein 6; D019485:Bone Morphogenetic Proteins; D011506:Proteins