title: Effects of 17β-estradiol and estrogen receptor antagonists on the proliferation of gastric cancer cell lines.
abstract: OBJECTIVE
  THE AIMS OF THIS STUDY WERE AS FOLLOW: 1) to de scribe the expression status of estrogen receptor-α and -β mRNAs in five gastric carcinoma cell lines; 2) to evaluate in vitro the effects of 17β-estradiol and estrogen receptor antagonists on the proliferation of the cell lines.
  
  
  METHODS
  Detection of estrogen receptor-α and estrogen receptor-β mRNA in five human gastric cancer cell lines (AGS, KATO III, MKN28, MKN45 and MKN74) was made by the reverse transcription-polymerase chain reaction system. To evaluate the effect of 17β-estradiol and estrogen receptor antagonists on the proliferation of gastric cancer cell line, the cell lines which expressed both es trogen receptors were chosen and treated with 17β-estradiol and estrogen receptor antagonists (methyl-piperidino-pyrazole and pyrazolo [1,5-a] pyrimidine). Cell proliferation was assessed with the methylthiazol tetrazolium test.
  
  
  RESULTS
  Estrogen receptor-α and estrogen receptor-β mRNAs were expressed in three (KATO III, MKN28 and MKN45) and all of the five gastric cancer cell lines, respectively. At higher concentrations, 17β-estradiol inhibited cell growth of MKN28, MKN45 and KATO III cell lines. Neither estrogen receptor-α nor estrogen receptor-β antagonist blocked the anti-proliferative effect of 17β-estradiol.
  
  
  CONCLUSIONS
  Our results indicate that estrogen receptor-β mRNAs are preferentially expressed in gastric cancers and also imply that hormone therapy rather than estrogen receptor blockers may be a useful strategy for the treatment of estrogen receptor-β positive gastric cancer. Its therapeutic significance in gastric cancer are, however, limited until more evidence of the roles of estrogen receptors in the gastric cancer are accumulated.
authors.affiliation: Department of Surgery, Korea University College of Medicine, Seoul, Korea.
authors.forename: Myung-Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Sung-Il
authors.initials: SI
authors.lastname: Cho
authors.forename: Kun-Ok
authors.initials: KO
authors.lastname: Lee
authors.forename: Hyung-Joon
authors.initials: HJ
authors.lastname: Han
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Song
authors.forename: Seong-Heum
authors.initials: SH
authors.lastname: Park
keywords: Cell line; Estrogens; Receptors, estrogen; Stomach neoplasms