Balıkesir Sağlık Bilimleri Dergisi (BSBD), vol.13, no.1, pp.75-82, 2024 (Peer-Reviewed Journal)
Objective: This study aims to evaluate the expression of Bone morphogenic proteins (BMP) -2, -4, -7, Transforming growth factor (TGF) -β1, and Gremlin1 in different subtypes of naturally occurring canine osteosarcoma (OS) by immunohistochemical method and contribute to a better understanding of the tumor microenvironment. Materials and Methods: Formalin-fixed, paraffin-embedded blocks of 16 naturally occurring canine OS were used. The tumors were classified according to the modified WHO's international histological classification of pet tumors. Compact bone tissues from five normal dogs were used as controls. Results: Immunohistochemically, BMP-2,-4, -7, TGF-β1, and Gremlin1 were not expressed in control tissues. BMP-2, -4, -7, TGF-β1, and Gremlin1 were expressed by undifferentiated mesenchymal cells and extracellular matrix in all OS subtypes. However, it was seen that there were differences in the expressions of these factors in different components of the tumor tissue. Although BMP-2, -4, -7, TGF-β1, and Gremlin1 have antagonistic effects in some pathways, they were co-expressed simultaneously in some regions in different OS subtypes. Conclusion: It was concluded that BMP-2, -4, -7, TGF-β1, and Gremlin1 could be expressed together in the same or different components of tumor tissues, and each can affect the behavior of tumor cells with their together or independent roles.