title: Significance of cyclooxygenase-2 expression in human primary hepatocellular carcinoma.
abstract: OBJECTIVE
  To clarify the significance of cyclooxygenase-2 (COX-2) expression in human primary hepatocellular carcinoma (HCC) and adjacent nontumorous tissues.
  
  
  METHODS
  The COX-2 protein and mRNA were investigated in 27 HCC tissues with adjacent nontumorous tissues, and 5 histologically normal liver tissues,using immunohistochemistry and in situ hybridization.
  
  
  RESULTS
  The well-differentiated HCC expressed COX-2 protein (5.68+/-1.19) more strongly than moderated HCC (3.43+/-1.98) and poor differentiated HCC (3.33+/-1.50) (P<0.05 respectively), adjacent nontumorous tissues (4.93+/-1.05) and normal liver tissues (3.20+/-1.92) (P<0.01 respectively); More intensive staining of COX-2 in adjacent nontumorous tissues was observed than that in normal liver tissues (P<0.05). There was no significant difference among adjacent nontumorous tissues, moderately differentiated HCC and poorly differentiated HCC (P>0.05). The expression of COX-2 mRNA was observed in the cytoplasm of the cells of HCC and of the hepatocytes in adjacent nontumorous tissues in which COX-2 protein was positive.
  
  
  CONCLUSIONS
  The overexpression of COX-2 in well-differentiated HCC suggests that COX-2 may play a role in the early stages of hepatocarcinogensis.
authors.affiliation: Shanghai Institute of Digestive Diseases, Renji Hospital, Shanghai Second Medical University, Shanghai, 200001, China. dekaiqiu@sh163.net
authors.forename: De-Kai
authors.initials: DK
authors.lastname: Qiu
authors.forename: Xiong
authors.initials: X
authors.lastname: Ma
authors.forename: Yan-Shen
authors.initials: YS
authors.lastname: Peng
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Chen
mesh_terms: D006528:Carcinoma, Hepatocellular; D051546:Cyclooxygenase 2; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D022781:Hepatocytes / Q000201:enzymology; D006801:Humans; D007527:Isoenzymes / Q000032:analysis / Q000235:genetics*; D008113:Liver Neoplasms; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D014407:Tumor Cells, Cultured
chemical_list: D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases