title: Primary tumorectomy promotes angiogenesis and pulmonary metastasis in osteosarcoma-bearing nude mice.
abstract: OBJECTIVE
  To investigate the effect of primary tumorectomy on angiogenesis and pulmonary metastasis in osteosarcoma-bearing nude mice.
  
  
  METHODS
  Osteosarcoma was introduced to nude mice via subcutaneous injection of MG-63 cells. One hundred and eighty osteosarcoma-bearing mice were used equally in 3 parallel experiments. The effect of tumorectomy (TR) on the expression of vascular endothelial growth factor (VEGF) and endostatin was investigated by ELISA. Meanwhile, the effect on angiogenesis was evaluated by Matrigel plug assay, and pulmonary metastasis assessed by calculating the metastatic foci. Sham-operation (SO) and untreated (UT) groups served as controls.
  
  
  RESULTS
  The VEGF (TR: 79.55 ± 7.82 pg/mL vs. SO: 110.01 ± 5.69 pg/mL, UT: 123.50 ± 10.41 pg/mL; p < 0.01) and endostatin (TR: 47.09 ± 6.22 ng/mL vs. SO: 117.64 ± 7.39 ng/mL, UT: 126.73 ± 6.55 ng/mL; p<0.01) were down-regulated significantly after tumorectomy, and angiogenesis was significantly promoted simultaneously. The incidence of pulmonary metastatic foci was 80.0% in the TR group, 40.0% in the SO group and 35.0% in the UT group.
  
  
  CONCLUSIONS
  Primary tumorectomy can down-regulate the expression of VEGF and endostatin and promote angiogenesis which leads to the acceleration of pulmonary metastasis. These findings imply that anti-angiogenic treatment can be considered after primary tumorectomy.
authors.affiliation: Department of Orthopedic Surgery, Tongji Hospital, Tongji University, Shanghai, China.
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Wang
authors.forename: Jiong
authors.initials: J
authors.lastname: Mei
authors.forename: You-Shui
authors.initials: YS
authors.lastname: Gao
authors.forename: Ming
authors.initials: M
authors.lastname: Ni
authors.forename: Bin
authors.initials: B
authors.lastname: Yao
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000473:pathology* / Q000601:surgery*; D003094:Collagen / Q000008:administration & dosage; D004338:Drug Combinations; D043169:Endostatins / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006454:Hemoglobins / Q000032:analysis; D007797:Laminin / Q000008:administration & dosage; D008175:Lung Neoplasms / Q000556:secondary*; D051379:Mice; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000209:etiology* / Q000473:pathology; D012516:Osteosarcoma / Q000556:secondary* / Q000601:surgery*; D011509:Proteoglycans / Q000008:administration & dosage; D013997:Time Factors; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
chemical_list: D004338:Drug Combinations; D043169:Endostatins; D006454:Hemoglobins; D007797:Laminin; D011509:Proteoglycans; D042461:Vascular Endothelial Growth Factor A; C059485:matrigel; D003094:Collagen