title: Relationship between cyclooxygenase-2 expression and K-ras gene mutation in colorectal adenomas.
abstract: OBJECTIVE
  Cyclooxygenase (COX)-2 has a trophic effect on gastrointestinal epithelial cells and is associated with the progression of colorectal adenomas. Mutation of the K-ras gene is also associated with the progression of colorectal adenomas and has recently been suggested to play an important role in the induction of COX-2. In the present study, we investigated the relationship between COX-2 expression and K-ras mutation in colorectal adenomas.
  
  
  METHODS
  Twenty-nine colorectal adenomas were obtained from specimens resected by the use of surgery or endoscopic mucosal resection and analyzed clinicopathologically. Immunohistochemistry was performed to analyze COX-2 expression in the adenoma specimens. The K-ras codon 12 mutations were detected by using the polymerase chain reaction-restriction fragment length polymorphism method.
  
  
  RESULTS
  An increase of COX-2-positive cells in adenoma was observed in 11 (37.9%) lesions, 10 (90.9%) of which had a K-ras gene mutation, suggesting a significant correlation between COX-2 expression and K-ras gene mutation in colorectal adenomas. Morphologically, COX-2-positive adenomas (13.8 +/- 2.6 mm) were significantly larger than COX-2-negative ones (5.8 +/- 0.9 mm). In addition, the increase of COX-2-positive cells in the lesion was observed more frequently in tubulovillous (63.6%) than in tubular (36.4%) adenoma.
  
  
  CONCLUSIONS
  Cycloxygenase-2 expression in colorectal adenoma cells is strongly correlated with K-ras gene mutation, suggesting that COX-2 and mutated K-ras are connectively associated with the progression of colorectal adenoma.
authors: Department of Pathology, Dokkyo University School of Medicine, Mibu, Tochigi, Japan.
authors: M
authors: M
authors: Fujita
authors: H
authors: H
authors: Fukui
authors: T
authors: T
authors: Kusaka
authors: K
authors: K
authors: Morita
authors: S
authors: S
authors: Fujii
authors: Y
authors: Y
authors: Ueda
authors: T
authors: T
authors: Chiba
authors: C
authors: C
authors: Sakamoto
authors: H
authors: H
authors: Kawamata
authors: T
authors: T
authors: Fujimori
mesh_terms: D000236:Adenoma / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D051546:Cyclooxygenase 2; D011905:Genes, ras; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D008565:Membrane Proteins; D009154:Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases