title: Cyclooxygenase 2 in gastric carcinoma is expressed in doublecortin- and CaM kinase-like-1-positive tuft cells.
abstract: OBJECTIVE
  Doublecortin and CaM kinase-like-1 (DCAMKL1) is a marker of stem cells expressed predominantly in the crypt base in the intestine. However, DCAMKL1-positive cells have been shown to be differentiated tuft cells rather than quiescent progenitors. Tuft cells are the only epithelial cells that express cyclooxygenase 2 (COX-2) in the normal intestinal epithelium. We previously generated Cdx2-transgenic mice as model mice for intestinal metaplasia and gastric carcinoma. In the current study, we investigated the association between COX-2 and DCAMKL1 in gastric carcinoma.
  
  
  METHODS
  We examined the association between COX-2 and DCAMKL1 expression in gastric carcinomas in clinical samples (early gastric well-differentiated adenocarcinoma) and Cdx2-transgenic mice; and the DCAMKL1-transgenic mouse stomach using immunohistochemistry and quantitative real-time polymerase chain reaction.
  
  
  RESULTS
  The COX-2-expressing cells were scattered, not diffusely expressed, in gastric carcinomas from humans and Cdx2-transgenic mice. DCAMKL1-positive cells were also scattered in the gastric carcinomas, indicating that tuft cells could still be present in gastric carcinoma. COX-2 was expressed in DCAMKL1-positive tuft cells in Cdx2- and DCAMKL1-transgenic mouse stomachs, whereas the Sox9 transcription factor was ubiquitously expressed in gastric carcinomas, including COX-2-positive cells.
  
  
  CONCLUSIONS
  COX-2 is expressed in DCAMKL1-expressing quiescent tuft cells in gastric carcinoma.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Jichi Medical University, Tochigi, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mutoh
authors.affiliation: Division of Gastroenterology, Department of Medicine, Jichi Medical University, Tochigi, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Sashikawa
authors.affiliation: Division of Gastroenterology, Department of Medicine, Jichi Medical University, Tochigi, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: Division of Gastroenterology, Department of Medicine, Jichi Medical University, Tochigi, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Tateno
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D000818:Animals; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D000089742:Doublecortin-Like Kinases; D004847:Epithelial Cells / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000235:genetics
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D055758:SOX9 Transcription Factor; D051546:Cyclooxygenase 2; C117347:DCLK1 protein, human; D000089742:Doublecortin-Like Kinases; C485525:Dclk1 protein, mouse; D017346:Protein Serine-Threonine Kinases
keywords: Cdx2-transgenic mice; Sox9; Stem cell marker