title: An immunohistochemical analysis for cancer of the esophagus using monoclonal antibodies specific for modified nucleosides.
abstract: BACKGROUND
  Modified nucleosides such as 1-methyl-adenosine and pseudouridine exist as minute components of transfer ribonucleic acid (tRNA) and are excreted in the urine in large amounts in the presence of malignancy. Although use of these modified nucleosides as tumor markers has long been studied and many reports have detailed their relationship with malignant tumors and the urinary excretion of various modified nucleosides, there have been no reports on modified nucleosides in esophageal carcinoma.
  
  
  METHODS
  Monoclonal antibody patterns against 1-methyladenosine and pseudouridine were studied in esophageal carcinoma, freshly resected esophageal carcinoma tissue specimens fixed in 10% neutral formaldehyde solution, embedded in paraffin, and sectioned for immunohistochemical study. Inhibition enzyme-linked immunosorbent assay (ELISA) was used to examine urinary excretion of these modified nucleosides in patients with esophageal carcinoma.
  
  
  RESULTS
  Although rare in normal esophageal epithelium, these modified nucleosides were strongly stained in esophageal carcinoma cells. Most carcinoma cells exhibited a cytoplasmic pattern, although some cells at the infiltrating edge displayed a nuclear pattern. These modified nucleosides were intensely imaged in 11 of 12 cultured esophageal cell lines, the exception being one line that had a much longer doubling time. Using ELISA, urinary excretion of these modified nucleosides was found to be significantly higher in patients with esophageal carcinoma than in healthy subjects; such excretion correlated with carcinoma size and stage and tended to decrease after treatment.
  
  
  CONCLUSIONS
  These findings indicate that the modified nucleosides 1-methyladenosine and pseudouridine may be useful as tumor markers for esophageal carcinoma.
authors.affiliation: Second Department of Surgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Masuda
authors.forename: T
authors.initials: T
authors.lastname: Nishihira
authors.forename: K
authors.initials: K
authors.lastname: Itoh
authors.forename: M
authors.initials: M
authors.lastname: Mizugaki
authors.forename: N
authors.initials: N
authors.lastname: Ishida
authors.forename: S
authors.initials: S
authors.lastname: Mori
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000276:immunology / Q000652:urine; D000911:Antibodies, Monoclonal / Q000276:immunology; D014408:Biomarkers, Tumor / Q000652:urine*; D002277:Carcinoma / Q000737:chemistry / Q000473:pathology / Q000652:urine*; D004797:Enzyme-Linked Immunosorbent Assay; D004938:Esophageal Neoplasms / Q000737:chemistry / Q000473:pathology / Q000652:urine*; D006801:Humans; D007150:Immunohistochemistry; D009367:Neoplasm Staging; D011560:Pseudouridine / Q000276:immunology / Q000652:urine*; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D011560:Pseudouridine; C002230:1-methyladenosine; D000241:Adenosine