title: Thymidylate synthase (TS) gene expression in primary lung cancer patients: a large-scale study in Japanese population.
abstract: BACKGROUND
  Previous small-sized studies showed lower thymidylate synthase (TS) expression in adenocarcinoma of the lung, which may explain higher antitumor activity of TS-inhibiting agents such as pemetrexed.
  
  
  METHODS
  To quantitatively measure TS gene expression in a large-scale Japanese population (n = 2621) with primary lung cancer, laser-captured microdissected sections were cut from primary tumors, surrounding normal lung tissues and involved nodes.
  
  
  RESULTS
  TS gene expression level in primary tumor was significantly higher than that in normal lung tissue (mean TS/β-actin, 3.4 and 1.0, respectively; P < 0.01), and TS gene expression level was further higher in involved node (mean TS/β-actin, 7.7; P < 0.01). Analyses of TS gene expression levels in primary tumor according to histologic cell type revealed that small-cell carcinoma showed highest TS expression (mean TS/β-actin, 13.8) and that squamous cell carcinoma showed higher TS expression as compared with adenocarcinoma (mean TS/β-actin, 4.3 and 2.3, respectively; P < 0.01); TS gene expression was significantly increased along with a decrease in the grade of tumor cell differentiation. There was no significant difference in TS gene expression according to any other patient characteristics including tumor progression.
  
  
  CONCLUSIONS
  Lower TS expression in adenocarcinoma of the lung was confirmed in a large-scale study.
authors.affiliation: Second Department of Surgery, University of Environmental and Occupational Health, Kitakakyushu, Japan. ftanaka@med.uoeh-u.ac.jp
authors.forename: F
authors.initials: F
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Wada
authors.forename: Y
authors.initials: Y
authors.lastname: Fukui
authors.forename: M
authors.initials: M
authors.lastname: Fukushima
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007564:Japan; D008175:Lung Neoplasms / Q000201:enzymology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D013940:Thymidylate Synthase / Q000235:genetics*; D055815:Young Adult
chemical_list: D013940:Thymidylate Synthase