title: Inhibition of lung metastasis of osteosarcoma cell line POS-1 transplanted into mice by thigh ligation.
abstract: Using a model with external ligation of the thigh, the effect of ischemia-reperfusion injury on tumor growth and the activity of lung metastasis was investigated in mice inoculated a spontaneous murine osteosarcoma cell line (POS-1) in vivo. POS-1 cell suspension was inoculated into the right hind footpad of 70 mice. Four weeks after inoculation, the ipsilateral thigh was ligated for 3 h in 15 mice and the contralateral thigh in 15 mice. Another ten mice were inoculated with POS-1 without ligating the thigh. The number of metastatic foci on the lung surface 6 weeks after inoculation was 2.29+/-0.98 (mean+/-SE) foci/lungs in mice with ipsilateral ligation and 6.25+/-2.41 in mice with contralateral ligation, which were significantly lower than control (13.40+/-1.42 in mice no ligation) (P<0.01). The number of metastatic foci on the lung surface in mice with intraperitoneal injection of superoxide dismutase (SOD) and catalase was 3.25+/-0.65 (mean+/-SE) foci/lungs in mice with ligation which was significantly greater than that in mice without SOD and catalase injection 1.29+/-0.97 (P=0.04). Cell viability was 9.12+/-4.07% with 100 microM H(2)O(2) in 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. It revealed that at concentrations of 100 microM H(2)O(2) or higher was cytotoxic to POS-1. In cell invasion assay, the number of invading cells with 10 microM H(2)O(2) was 2.80+/-0.53 cells/field, which was significantly lower than control (5.93+/-0.18) (mean+/-SE), indicating that low-dose H(2)O(2) suppressed invasion of POS-1. These results suggested that reperfusion injury had selective cytotoxicity to POS-1 through producing reactive oxygen species. Activated oxygen was considered to inhibit the regional growth and the ability of lung metastasis of POS-1 cells.
authors.affiliation: Department of Orthopaedic Surgery, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan. akamijoyokohama@aol.com
authors.forename: Akira
authors.initials: A
authors.lastname: Kamijo
authors.forename: Tomihisa
authors.initials: T
authors.lastname: Koshino
authors.forename: Masaaki
authors.initials: M
authors.lastname: Uesugi
authors.forename: Hironori
authors.initials: H
authors.lastname: Nitto
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Saito
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology*; D002374:Catalase / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival; D004195:Disease Models, Animal; D005562:Formazans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008026:Ligation; D008175:Lung Neoplasms / Q000378:metabolism / Q000517:prevention & control* / Q000556:secondary; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009368:Neoplasm Transplantation; D012516:Osteosarcoma / Q000378:metabolism / Q000517:prevention & control* / Q000556:secondary; D017382:Reactive Oxygen Species / Q000378:metabolism / Q000627:therapeutic use*; D015427:Reperfusion Injury / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D013778:Tetrazolium Salts; D013848:Thigh / Q000098:blood supply; D014407:Tumor Cells, Cultured
chemical_list: D005562:Formazans; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; C079782:MTT formazan; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase