title: Nitric oxide pathways in human bladder carcinoma. The distribution of nitric oxide synthases, soluble guanylyl cyclase, cyclic guanosine monophosphate, and nitrotyrosine.
abstract: BACKGROUND
  Nitric oxide (NO) is produced by a group of synthase enzymes (NOS). By means of different pathways, NO exerts several functions in benign and malignant human bladder tissues. The current paper describes the NO/guanylate cyclase (sGC)/cyclic guanosine monophosphate (cGMP) and the NO/oxidative pathways in human bladder tissues.
  
  
  METHODS
  Bladder carcinoma tissues were collected from 18 patients by transurethral resection procedures. Normal benign vesical tissue specimens from a further eight patients with benign diseases served as controls. Immunohistochemistry was conducted for localization of sGC, cGMP, and nitrotyrosine in benign and malignant vesical tissues, evaluating two-three tissue sections per patient.
  
  
  RESULTS
  Positive immunolabeling for sGC and cGMP was detected in vascular endothelial cells of normal and malignant vesical tissues. Those signals were most intense in bladder carcinoma tissues. Immunolabeling for sGC and cGMP was also detected in normal urothelial cells. In bladder carcinoma cells, a heterogeneous immunolabeling for sGC and cGMP was seen, with a wide spectrum of signal intensity. Positive immunostaining for sGC and cGMP was also observed in stromal round cells in benign and malignant bladder tissues. Immunolabeling for nitrotyrosine was mainly observed in endothelial cells, with a much stronger immunolabeling in bladder carcinoma tissues compared to normal benign controls. A weak immunolabeling for nitrotyrosine was also observed in bladder carcinoma cells. Normal urothelial cells did not show such nitrotyrosine expression.
  
  
  CONCLUSIONS
  The current report provides evidences that NO play several roles through different pathways in benign and malignant vesical tissues. The influences generated by NO molecules can be divided into cGMP-mediated effects (those resulting from the NO/sGC/cGMP pathway) and non-cGMP-mediated effects (those resulting from the NO/oxidative pathway). Increased angiogenesis is a cGMP-mediated effect, while nitrotyrosine production is a non cGMP-mediated oxidative effect. Such an NO/oxidative pathway is observed more often in bladder carcinoma.
authors.affiliation: Department of Urology, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: Amgad
authors.initials: A
authors.lastname: Ehsan
authors.forename: Frank
authors.initials: F
authors.lastname: Sommer
authors.forename: Annette
authors.initials: A
authors.lastname: Schmidt
authors.forename: Theodor
authors.initials: T
authors.lastname: Klotz
authors.forename: Jolanta
authors.initials: J
authors.lastname: Koslowski
authors.forename: Sandra
authors.initials: S
authors.lastname: Niggemann
authors.forename: Georg
authors.initials: G
authors.lastname: Jacobs
authors.forename: Udo
authors.initials: U
authors.lastname: Engelmann
authors.forename: Klaus
authors.initials: K
authors.lastname: Addicks
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Bloch
mesh_terms: D000368:Aged; D015153:Blotting, Western; D002277:Carcinoma / Q000201:enzymology / Q000503:physiopathology*; D002471:Cell Transformation, Neoplastic; D006152:Cyclic GMP / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006162:Guanylate Cyclase / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D009389:Neovascularization, Pathologic; D009569:Nitric Oxide / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000494:pharmacology*; D010084:Oxidation-Reduction; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D001749:Urinary Bladder Neoplasms / Q000201:enzymology / Q000503:physiopathology*
chemical_list: D016166:Free Radical Scavengers; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D019001:Nitric Oxide Synthase; D006162:Guanylate Cyclase; D006152:Cyclic GMP