title: High-risk gastrointestinal stromal tumour (GIST) and synovial sarcoma display similar angiogenic profiles: a nude mice xenograft study.
abstract: BACKGROUND
  Gastrointestinal stromal tumour (GIST) is the most common primary mesenchymal tumour of the gastrointestinal tract. Spindle cell monophasic synovial sarcoma (SS) can be morphologically similar. Angiogenesis is a major factor for tumour growth and metastasis. Our aim was to compare the angiogenic expression profiles of high-risk GIST and spindle cell monophasic SS by histological, immunohistochemical and molecular characterisation of the neovascularisation established between xenotransplanted tumours and the host during the initial phases of growth in nude mice.
  
  
  METHODS
  The angiogenic profile of two xenotransplanted human soft-tissue tumours were evaluated in 15 passages in nude mice using tissue microarrays (TMA). Tumour pieces were also implanted subcutaneously on the backs of 14 athymic Balb-c nude mice. The animals were sacrificed at 24, 48, and 96 h; and 7, 14, 21, and 28 days after implantation to perform histological, immunohistochemical, and molecular studies (neovascularisation experiments).
  
  
  RESULTS
  Morphological similarities were apparent in the early stages of neoplastic growth of these two soft-tissue tumours throughout the passages in nude mice and in the two neovascularisation experiments. Immunohistochemistry demonstrated overexpression of pro-angiogenic factors between 24 h and 96 h after xenotransplantation in both tumours. Additionally, neoplastic cells coexpressed chemokines (CXCL9, CXCL10, GRO, and CXCL12) and their receptors in both tumours. Molecular studies showed two expression profiles, revealing an early and a late phase in the angiogenic process.
  
  
  CONCLUSIONS
  This model could provide information on the early stages of the angiogenic process in monophasic spindle cell SS and high-risk GIST and offers an excellent way to study possible tumour response to antiangiogenic drugs.
authors.affiliation: Department of Pathology, Universitat de València Estudi General (UVEG), València 46010, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Giner
authors.affiliation: Department of Pathology, Fundación Instituto Valenciano de Oncología (FIVO), Valencia 46009, Spain.
authors.forename: Isidro
authors.initials: I
authors.lastname: Machado
authors.affiliation: Laboratory of Molecular Biology, Fundación Instituto Valenciano de Oncología (FIVO), Valencia 46009, Spain.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Lopez-Guerrero
authors.affiliation: Department of Pathology, Universitat de València Estudi General (UVEG), València 46010, Spain.
authors.forename: Empar
authors.initials: E
authors.lastname: Mayordomo-Aranda
authors.affiliation: Department of Pathology, Universitat de València Estudi General (UVEG), València 46010, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Llombart-Bosch
keywords: GIST; angiogenesis; chemokines; nude mice xenograft; synovial sarcoma