title: Systemic RANK-Fc protein therapy is efficacious against primary osteosarcoma growth in a murine model via activity against osteoclasts.
abstract: OBJECTIVE
  Osteosarcoma (OS) is the most common primary malignant bone tumour, and mainly affects adolescents and young adults. Although there has been substantial improvement in management of OS with surgery and chemotherapy, further survival increase has not been achieved over the past two decades.
  
  
  METHODS
  We focused on the receptor activator of nuclear factor kappaB ligand (RANKL)-osteoclast (OCL) system as a biological target for OS. RANKL is a critical factor for OCL formation and bone resorption activity. The primary lesion in bone and ensuing metastasis in OS both require the induction of OCLs. RANK-Fc is a potent RANKL antagonist and inhibitor of OCL formation and activity.
  
  
  RESULTS
  In an orthotopic model in Balb/c nu/nu mice, a twice weekly dosing regimen of 350 microg of RANK-Fc per mouse subcutaneously (n= 5) reduced lung metastasis (P > 0.05), preserved bone structure and reduced tartrate-resistant acid phosphatase (TRAP)(+) OCLs (P < 0.005) in OS-bearing bone. In vitro, RANK-Fc suppressed OCL formation (P < 0.005), bone resorption activity (P < 0.005) and RANKL-induced anti-apoptosis (P < 0.5) of OCLs.
authors.affiliation: Department of Orthopaedics and Surgery, University of Melbourne, Australia.
authors.forename: Toru
authors.initials: T
authors.lastname: Akiyama
authors.forename: Crispin R
authors.initials: CR
authors.lastname: Dass
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Shinoda
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kawano
authors.forename: Sakae
authors.initials: S
authors.lastname: Tanaka
authors.forename: Peter F M
authors.initials: PF
authors.lastname: Choong
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D001862:Bone Resorption / Q000188:drug therapy; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008175:Lung Neoplasms / Q000188:drug therapy / Q000209:etiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D010010:Osteoclasts / Q000187:drug effects*; D012516:Osteosarcoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D053245:RANK Ligand / Q000037:antagonists & inhibitors*; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000494:pharmacology / Q000627:therapeutic use*; D000071681:Tartrate-Resistant Acid Phosphatase
chemical_list: D007527:Isoenzymes; D053245:RANK Ligand; C517736:Rank-Fc; D053246:Receptor Activator of Nuclear Factor-kappa B; D011993:Recombinant Fusion Proteins; D000135:Acid Phosphatase; C000605511:Acp5 protein, mouse; D000071681:Tartrate-Resistant Acid Phosphatase