title: In vitro retinoid-induced growth inhibition and morphologic differentiation of canine osteosarcoma cells.
abstract: OBJECTIVE
  To determine differentiation and growth inhibition effects of retinoids on canine osteosarcoma cells.
  
  
  METHODS
  3 osteosarcoma cell lines established from osteosarcomas in dogs.
  
  
  METHODS
  Osteosarcoma cells were incubated with various concentrations of all-trans-retinoic acid and 9-cis-retinoic acid or control medium, counted daily for 10 days, and evaluated for morphologic changes. Synthesis of DNA was measured by use of a cell proliferation ELISA. To analyze effect of retinoids on colony formation on plastic dishes, cells were cultured for 14 days, fixed, and stained; number of colonies was counted.
  
  
  RESULTS
  In a dose-dependent manner, both retinoids induced morphologic differentiation and growth inhibition in the 3 osteosarcoma cell lines and inhibited each cell's ability to form anchorage-dependent colonies.
  
  
  CONCLUSIONS
  Retinoids induced differentiation of osteosarcoma cells of dogs, resulting in altered expression of their malignant phenotype. Induction of differentiation by retinoids may have potential as an adjunctive treatment for osteosarcoma in dogs.
authors.affiliation: Division of Veterinary Medical Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
authors.forename: S H
authors.initials: SH
authors.lastname: Hong
authors.forename: T
authors.initials: T
authors.lastname: Kadosawa
authors.forename: K
authors.initials: K
authors.lastname: Nozaki
authors.forename: M
authors.initials: M
authors.lastname: Mochizuki
authors.forename: S
authors.initials: S
authors.lastname: Matsunaga
authors.forename: R
authors.initials: R
authors.lastname: Nishimura
authors.forename: N
authors.initials: N
authors.lastname: Sasaki
mesh_terms: D000077556:Alitretinoin; D000818:Animals; D000963:Antimetabolites / Q000737:chemistry; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*; D001973:Bromodeoxyuridine / Q000737:chemistry; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D004283:Dog Diseases / Q000188:drug therapy* / Q000473:pathology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D008858:Microscopy, Phase-Contrast / Q000662:veterinary; D012516:Osteosarcoma / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*; D014212:Tretinoin / Q000494:pharmacology* / Q000627:therapeutic use; D014407:Tumor Cells, Cultured
chemical_list: D000963:Antimetabolites; D000970:Antineoplastic Agents; D000077556:Alitretinoin; D014212:Tretinoin; D004247:DNA; D001973:Bromodeoxyuridine