title: Osteoprotegerin inhibits tumor-induced osteoclastogenesis and bone tumor growth in osteopetrotic mice.
abstract: Osteoprotegerin and osteoprotegerin ligand have recently been identified as novel proteins that inhibit and stimulate, respectively, osteoclast formation. We examined the possibility that osteoprotegerin would inhibit cancer-induced osteoclastogenesis and cancer growth in bone. An experimental model was used in which osteolytic tumors are known to stimulate osteoclastogenesis and grow in femora of osteoclast-deficient mice (op/op). Osteoprotegerin treatment decreased the number of osteoclasts by 90% (p < 0.0007) at sites of tumor in a dose-dependent manner and decreased bone tumor area by greater than 90% (p < 0.003). The mechanisms through which osteoprotegerin decreased osteoclast formation in tumor-bearing animals included (a) an osteoprotegerin-mediated, systemic reduction in the number of splenic and bone marrow-residing osteoclast precursor cells, (b) a decrease in the number of osteoclast precursor cells at sites of tumor as detected by cathepsin K and receptor activator of NFkappaB mRNA expression, and (c) a decrease in osteoprotegerin ligand mRNA at sites of tumor. These findings suggest that osteoprotegerin treatment, in addition to having direct antagonistic effects on endogenous osteoprotegerin ligand, decreases the number of osteoclast precursors and reduces production of osteoprotegerin ligand at sites of osteolytic tumor.
authors.affiliation: Department of Orthopaedic Surgery, University of Minnesota Medical School, and University of Minnesota Cancer Center, Minneapolis 55455, USA. clohi001@tc.umn.edu
authors.forename: D R
authors.initials: DR
authors.lastname: Clohisy
authors.forename: M L
authors.initials: ML
authors.lastname: Ramnaraine
authors.forename: S
authors.initials: S
authors.lastname: Scully
authors.forename: M
authors.initials: M
authors.lastname: Qi
authors.forename: G
authors.initials: G
authors.lastname: Van
authors.forename: H L
authors.initials: HL
authors.lastname: Tan
authors.forename: D L
authors.initials: DL
authors.lastname: Lacey
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D002352:Carrier Proteins / Q000235:genetics; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005269:Femur / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000502:physiology; D006023:Glycoproteins / Q000494:pharmacology*; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics; D008562:Membrane Glycoproteins / Q000235:genetics; D051379:Mice; D008815:Mice, Inbred Strains; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010014:Osteolysis / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D010022:Osteopetrosis / Q000473:pathology / Q000503:physiopathology; D053244:Osteoprotegerin; D044162:Parathyroid Hormone-Related Protein; D011506:Proteins / Q000235:genetics; D053245:RANK Ligand; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000473:pathology / Q000637:transplantation
chemical_list: D002352:Carrier Proteins; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D053244:Osteoprotegerin; D044162:Parathyroid Hormone-Related Protein; D011506:Proteins; D053245:RANK Ligand; D012333:RNA, Messenger; D053246:Receptor Activator of Nuclear Factor-kappa B; D018160:Receptors, Cytoplasmic and Nuclear; D018124:Receptors, Tumor Necrosis Factor; C505687:Tnfrsf11a protein, mouse; C506031:Tnfrsf11b protein, mouse; C505689:Tnfsf11 protein, mouse; D016173:Macrophage Colony-Stimulating Factor