title: Expression of cyclooxygenase-2 in gastric cancer and its relation to liver metastasis and long-term prognosis.
abstract: OBJECTIVE
  To investigate the expression of cyclooxygenase-2 (COX-2) in gastric cancer and its relation with the liver metastasis and prognosis.
  
  
  METHODS
  Expression of COX-2 mRNA and protein was examined in gastric cancer and its paired substantial normal tissue by semi-quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. The relation between COX-2 expression and prognosis was investigated in 195 cases.
  
  
  RESULTS
  The expression of COX-2 mRNA in gastric cancer tissue was significantly higher than that in normal tissue in 47 cases (w = 792, P<0.01). The COX-2 mRNA in pT3-4 tissue expressed higher than that in pT1-2 tissue (w = 204, P<0.05). The positive expression rate of COX-2 protein was 57.9% (113/195). The COX-2 expression was significantly related to histological type, lymphnode metastasis, venous invasion and liver metastasis (P<0.05). No relation was found between COX-2 expression and invasion depth, peritoneal metastasis and International Union against Cancer TNM stage. The multiple regression analysis showed that the COX-2 expression and venous invasion were obviously associated with liver metastasis (P<0.05). However, there was no significant correlation between COX-2 immunoreactivity and prognosis.
  
  
  CONCLUSIONS
  COX-2 may play an important role in the development of gastric cancer, and the over-expression of COX-2 protein may be a high risk factor for liver metastasis.
authors.affiliation: Department of Gastrointestinal Surgery, First Affiliated Hospital, Medical School, Zhejiang University, Hangzhou 310003, Zhejiang Province, China.
authors.forename: Ji-Ren
authors.initials: JR
authors.lastname: Yu
authors.forename: Yi-Jun
authors.initials: YJ
authors.lastname: Wu
authors.forename: Qi
authors.initials: Q
authors.lastname: Qin
authors.forename: Ke-Zheng
authors.initials: KZ
authors.lastname: Lu
authors.forename: Sheng
authors.initials: S
authors.lastname: Yan
authors.forename: Xiao-Sun
authors.initials: XS
authors.lastname: Liu
authors.forename: Shu-Sen
authors.initials: SS
authors.lastname: Zheng
mesh_terms: D001483:Base Sequence; D051546:Cyclooxygenase 2; D017931:DNA Primers; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008113:Liver Neoplasms / Q000201:enzymology / Q000235:genetics / Q000556:secondary*; D008565:Membrane Proteins; D009362:Neoplasm Metastasis; D011379:Prognosis; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology
chemical_list: D017931:DNA Primers; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases