title: Cyclooxygenase-2 expression and its prognostic significance in clear cell renal cell carcinoma.
abstract: BACKGROUND
  The prognostic value of cyclooxygenase-2 (COX-2) in human renal cell carcinoma (RCC) remains unclear. The purposes of this study are to elucidate the clinical significance of COX-2 in clear cell RCC (CCRCC) and to assess the treatment effect of COX-2 inhibition on CCRCC cell lines.
  
  
  METHODS
  Using tumor samples obtained from 137 patients who had undergone nephrectomy at Seoul National University Hospital, we evaluated COX-2 expression on immunohistochemistry. Moreover, we performed the cell proliferation assay using 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-2H tetrazolium bromide (MTT) and cell invasion assay. Thus, we evaluated the effect of meloxicam, an inhibitor of COX-2, in two human CCRCC cell lines.
  
  
  RESULTS
  Cancer-specific survival (p=0.038) and progression-free survival (p=0.031) were shorter in the COX-2 high expression group. A multivariate logistic regression model showed that COX-2 expression was an independent risk factor for pTNM stage and Fuhrman nuclear grade. The MTT assay revealed that COX-2 inhibition led to the suppression of the proliferation of CCRCC cell lines. Moreover, it also reduced their invasion capacity.
  
  
  CONCLUSIONS
  This study postulates that COX-2 is a poor prognostic indicator in human CCRCC, suggesting that COX-2 inhibition can be a potential therapy in CCRCC.
authors.affiliation: Department of Pediatrics, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Jeong Hwan
authors.initials: JH
authors.lastname: Park
authors.forename: Ja Hee
authors.initials: JH
authors.lastname: Suh
authors.forename: Kyung Han
authors.initials: KH
authors.lastname: Nam
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Choe
authors.forename: Hae Yoen
authors.initials: HY
authors.lastname: Jung
authors.forename: Ji Yoen
authors.initials: JY
authors.lastname: Chae
authors.forename: Kyung Chul
authors.initials: KC
authors.lastname: Moon
keywords: Carcinoma, renal cell; Cyclooxygenase 2; Prognosis