title: Expression of estrogen receptors in gastric cancer and their clinical significance.
abstract: OBJECTIVE
  The male predominance of gastric cancer suggests that female sex hormones may have a protective effect against gastric cancer. We evaluated the expression of estrogen receptors in gastric cancer tissue and cells and the clinical significance of ER-β expression in gastric cancer.
  
  
  METHODS
  ER-α, ER-β proteins extracted from normal stomach, gastric cancer tissues, and cultured gastric cancer cells (KATO-III, mkn28, mkn45, and mkn74) were assessed by Western blot analysis. The clinical significance of ER-β was explored using tissue microarray methods and immunohistochemical staining of specimens from 148 gastric cancers.
  
  
  RESULTS
  Both ER-α and β protein expression were noted in normal and gastric cancer tissues. However, in cultured gastric cells, only ER-β was noted in mkn28 and mkn74. Of 148 gastric cancers, 67 (45.3%) were ER-β positive. The ER-β positive group was associated with lower tumor stage, Lauren's intestinal type, negative perineural invasion, and free of recurrence. The ER-β positive group had a better 3-year survival compared with the negative group in survival analysis.
  
  
  CONCLUSIONS
  Our results suggest that the presence of ER-β in gastric cancer could have a protective effect against invasiveness of gastric cancer. Further studies are needed to clarify the role of ER-β in gastric cancers.
authors.affiliation: Department of Surgery, Korea University College of Medicine, Seoul, Korea.
authors.forename: Woo-Sang
authors.initials: WS
authors.lastname: Ryu
authors.forename: Jong-Han
authors.initials: JH
authors.lastname: Kim
authors.forename: You-Jin
authors.initials: YJ
authors.lastname: Jang
authors.forename: Sung-Soo
authors.initials: SS
authors.lastname: Park
authors.forename: Jun-Won
authors.initials: JW
authors.lastname: Um
authors.forename: Seong-Heum
authors.initials: SH
authors.lastname: Park
authors.forename: Seung-Joo
authors.initials: SJ
authors.lastname: Kim
authors.forename: Young-Jae
authors.initials: YJ
authors.lastname: Mok
authors.forename: Chong-Suk
authors.initials: CS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D015153:Blotting, Western; D045744:Cell Line, Tumor; D047628:Estrogen Receptor alpha / Q000032:analysis; D047629:Estrogen Receptor beta / Q000032:analysis* / Q000502:physiology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000473:pathology; D046888:Tissue Array Analysis
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta