title: Inhibition by tumor necrosis factor of induction of ectopic bone formation by osteosarcoma-derived bone-inducing substance.
abstract: The effect of tumor necrosis factor alpha (TNF-alpha) on ectopic endochondral bone formation was studied in an experimental system for bone induction using murine osteosarcoma-derived bone-inducing substance. Ectopic new bone formation was inhibited by daily administration of recombinant human TNF-alpha (20-200 micrograms/kg body weight per day, intraperitoneally) after subcutaneous implantation of the bone-inducing substance into mice. Histological examination revealed that TNF-alpha prevented mesenchymal cells from differentiating into chondrocytes in the process of endochondral bone formation. The inhibitory effect of TNF-alpha continued during the period of its administration, but not after its administration was stopped. The bone induced in a three week period after discontinuation of TNF-alpha administration was histologically normal, but smaller than that induced in control animals. These findings suggested that TNF-alpha reversibly inhibits the biological activity of the bone-inducing substance or impairs the ability of cells to respond to the bone-inducing substance at an early stage of ectopic bone formation.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Medical School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: J
authors.initials: J
authors.lastname: Hashimoto
authors.forename: K
authors.initials: K
authors.lastname: Masuhara
authors.forename: K
authors.initials: K
authors.lastname: Takaoka
authors.forename: K
authors.initials: K
authors.lastname: Ono
mesh_terms: D000818:Animals; D006133:Growth Substances / Q000494:pharmacology*; D051379:Mice; D009363:Neoplasm Proteins / Q000494:pharmacology*; D009999:Ossification, Heterotopic / Q000139:chemically induced*; D010012:Osteogenesis / Q000187:drug effects*; D012516:Osteosarcoma / Q000032:analysis*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D006133:Growth Substances; D009363:Neoplasm Proteins; D014409:Tumor Necrosis Factor-alpha