title: Roles of bone morphogenetic protein signaling in osteosarcoma.
abstract: OBJECTIVE
  Since the original extraction of bone morphogenetic proteins (BMPs) from bovine bone, research interest and clinical use has increased exponentially. With this, a concomitant analysis of BMP expression in bone tumours has been performed. BMP ligands, receptors, and signaling activity have been observed in diverse benign and malignant bone tumours. However, the reported expression, function, and importance of BMPs in bone tumours, and specifically osteosarcomas, have been far from uniform. This review highlights recent advances in understanding the role of BMP signaling in osteosarcoma biology, focusing on the sometimes divergent findings by various researchers and the challenges inherent in the study of osteosarcoma.
  
  
  METHODS
  We performed a literature review of all studies examining BMP signaling in osteosarcoma.
  
  
  RESULTS
  Overall, multiple BMP ligands and receptors are expressed in most osteosarcoma cell lines and subtypes, although BMP signaling may be reduced in comparison with benign bone-forming tumours. Studies suggest that osteosarcomas with different lineages of differentiation may have differential expression of BMP ligands. Although significant disagreement in the literature exists, the presence of BMP signaling in osteosarcoma may impart a worse prognosis. On the cellular level, BMP signaling appears to mediate promigratory effects in osteosarcoma and chondrosarcoma cell types, possibly via interaction and activation of Integrin β1.
  
  
  CONCLUSIONS
  BMP signaling has clear biologic importance in osteosarcoma, although it is not yet fully understood. Future questions for study include assessing the utility of BMP signaling in prognostication of osteosarcoma and the potential modulation of BMP signaling for inhibition of osteosarcomagenesis, growth and invasion.
authors.affiliation: Department of Pathology & Laboratory Medicine, David Geffen School of Medicine, University of California, 10833 Le Conte Ave, CHS A3-251, Los Angeles, CA, 90077, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Nguyen
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Scott
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Dry
authors.forename: Aaron W
authors.initials: AW
authors.lastname: James
mesh_terms: D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D001859:Bone Neoplasms / Q000378:metabolism* / Q000473:pathology; D002417:Cattle; D002454:Cell Differentiation; D002813:Chondrosarcoma; D018450:Disease Progression; D005786:Gene Expression Regulation; D012516:Osteosarcoma / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D012983:Soft Tissue Neoplasms
chemical_list: D019485:Bone Morphogenetic Proteins