title: [Morphological changes in osteosarcoma xenografts in nude mice after inhibiting angiogenesis by Ad-VEGF-siRNA].
abstract: OBJECTIVE
  Vascular endothelial growth factor (VEGF) is a critical stimulator for angiogenesis of osteosarcoma. This study was to investigate the morphological changes in osteosarcoma xenografts in nude mice after inhibiting angiogenesis by Ad-VEGF-siRNA.
  
  
  METHODS
  The animal model of osteosarcoma xenografts was constructed by subcutaneous inoculation of osteosarcoma MG63 cells into nude mice. The mice were randomly divided into three groups, 15 mice in each group: group A and control groups B and C. The tumor nodules were injected with Ad-VEGF-siRNA in group A, an equal dose of Ad-EGFP and PBS, respectively, in groups B and C. The volume and weight of tumors were measured every two days after injection and the growth curves were drawn. The tumor samples were observed and analyzed using HE staining. Angiogenesis was assessed by immunohistochemical staining using anti-VEGF and CD31 antibodies. The ultrastructure of vasculogenic mimicry (VM) was observed using transmission electron microscopy (TEM).
  
  
  RESULTS
  The mean volume, weight, microvessel density (MVD) and VEGF expression of tumors in Ad-VEGF-siRNA-treated group were significantly lower than those in the control groups. MVD was positively correlated to VEGF expression, with a correlation coefficient of 0.9989. The number of VM was 1.40+/-0.55 in the Ad-VEGF-siRNA group, which was significantly less than those in the two control groups.
  
  
  CONCLUSIONS
  Ad-VEGF-siRNA could effectively block angiogenesis in osteosarcoma xenografts in nude mice.
authors.affiliation: Department of Orthopedics, Tongji Hospital, Tongji University, Shanghai 200065, P. R. China.
authors.forename: Jia-Qi
authors.initials: JQ
authors.lastname: Wang
authors.forename: You-Shui
authors.initials: YS
authors.lastname: Gao
authors.forename: Jiong
authors.initials: J
authors.lastname: Mei
authors.forename: Hua-Ming
authors.initials: HM
authors.lastname: Xue
authors.forename: Shu-Qing
authors.initials: SQ
authors.lastname: Wang
authors.forename: Xuan-Song
authors.initials: XS
authors.lastname: Cai
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D045744:Cell Line, Tumor; D005260:Female; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D055806:Microvessels / Q000473:pathology / Q000648:ultrastructure; D009368:Neoplasm Transplantation; D009389:Neovascularization, Pathologic / Q000517:prevention & control*; D012516:Osteosarcoma / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D011897:Random Allocation; D047368:Tumor Burden; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
chemical_list: D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A