Bone Morphogenetic Proteins (BMPs) in Musculoskeletal Oncology

Current knowledge of bone morphogenetic proteins (BMPs) in musculoskeletal oncology is reviewed in this paper. Bone morphogenetic activity, manifesting as ectopic bone induction, is present in a proportion of murine and human osteosarcoma tissues and cells in culture. In osteosarcoma, BMPs effect reactive bone formation including periosteal reactions by normal osteoblasts rather than through the production of tumorous osteoid by tumor cells. BMP-producing osteosarcomas may contain less differentiated mesenchymal cells, resulting in a poorer prognosis for these patients. BMP-2/4 proteins are also expressed in malignant fibrous histiocytoma, dedifferentiated chondrosarcoma, and a variety of soft-tissue sarcomas exhibiting undifferentiated features, suggesting that BMPs may have additional functions unrelated to bone formation. Clinically, BMPs have utility as new diagnostic and prognostic markets for characterizing the stage of differentiation of mesenchymal cells and mesenchymal tumors, and may be of value in predicting the prognosis of sarcoma patients.