title: Nitric oxide synthases, cyclooxygenase-2, nitrotyrosine, and angiogenesis in chondrosarcoma and their relation to prognosis.
abstract: BACKGROUND
  The localization in tumor tissue of various markers by immunohistochemistry can help to establish a diagnosis or predict prognosis. Nitric oxide is associated with tumors and has been studied indirectly by nitrotyrosine analysis and with use of the enzymes nitric oxide synthase (NOS)1, NOS2, and NOS3. Nitric oxide reacts with superoxide anions to yield peroxynitrite, which has toxic effects on genes. Peroxynitrite adds a nitro group to the benzene ring of tyrosine to form nitrotyrosine. The accumulation of nitrotyrosine, a stable product in cells, indicates the formation of peroxynitrite. Nitric oxide stimulates the production of cyclooxygenase-2 (COX-2), which has been associated with angiogenesis in tumors. Neovascularization influences tumor prognosis, as demonstrated by microvessel studies with use of CD34, an immunohistochemical endothelial cell marker. This study examines the expression of these markers in chondrosarcomas and their relation to histological grade and prognosis.
  
  
  METHODS
  Tissue microarrays composed of formalin-fixed tissue samples from 101 patients with chondrosarcoma were immunohistochemically stained to localize NOS1, NOS2, NOS3, COX-2, nitrotyrosine, and CD34. Five samples of normal cartilage were used as controls. Patient demographics, selected surgical variables, and tumor grade were tabulated, and the associations were analyzed. Analyses of local and overall survival rates were performed with use of the Kaplan-Meier method, and multivariable analyses were performed.
  
  
  RESULTS
  There was a significant association of nitrotyrosine, COX-2, and CD34 with histological grades (p = 0.022, p = 0.014, and p = 0.028, respectively), but not with overall prognosis (p = 0.064, p = 0.143, and p = 0.581, respectively). The presence of NOS2 was associated with a lower rate of local disease-free survival (p = 0.038), and positive expressions of NOS1 and NOS2 were associated with decreased overall survival rates (p = 0.007 and p < 0.001, respectively). On multivariable analysis, NOS2 expression demonstrated an independent prognostic impact on local disease-free survival; NOS1 and NOS2 expression was a dependent variable, and their isolated or combined expression was related to lower overall survival rates (p = 0.046 and p = 0.004) (hazard ratio, 3.17 [95% confidence interval, 1.0 to 9.8] and 5.58 [95% confidence interval, 1.7 to 18.0], respectively).
  
  
  CONCLUSIONS
  Immunohistochemical markers may have an independent value in predicting the prognosis for patients with chondrosarcoma.
authors.affiliation: Departamentos de Cirurgia Pélvica-Ortopedia, Hospital A.C. Camargo, Rua Prof. Antonio Prudente, 211, São Paulo - S. P., CEP 01509-010, Brazil. su@uol.com.br
authors.forename: Suely Akiko
authors.initials: SA
authors.lastname: Nakagawa
authors.forename: Ademar
authors.initials: A
authors.lastname: Lopes
authors.forename: André
authors.initials: A
authors.lastname: Lopes de Carvalho
authors.forename: Benedito Mauro
authors.initials: BM
authors.lastname: Rossi
authors.forename: Isabela
authors.initials: I
authors.lastname: Werneck da Cunha
authors.forename: Fernando Augusto
authors.initials: FA
authors.lastname: Soares
authors.forename: Wu Tu
authors.initials: WT
authors.lastname: Chung
authors.forename: Lucíola Assunção
authors.initials: LA
authors.lastname: Alves
mesh_terms: D018952:Antigens, CD34 / Q000096:biosynthesis; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D001859:Bone Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D002813:Chondrosarcoma / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D009367:Neoplasm Staging; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D011237:Predictive Value of Tests; D011379:Prognosis; D016019:Survival Analysis; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000096:biosynthesis
chemical_list: D018952:Antigens, CD34; D014408:Biomarkers, Tumor; C002744:3-nitrotyrosine; D014443:Tyrosine; D019001:Nitric Oxide Synthase; D051546:Cyclooxygenase 2