title: Brief tamoxifen pretreatment enhances the chemosensitivity of gastric carcinoma cells to 5-fluorouracil in vitro.
abstract: BACKGROUND
  Estrogen receptors (ERs) have been detected in gastric carcinoma cells in vivo and in vitro. Several in vitro and in vivo studies examining the potential beneficial effects of adjuvant Tamoxifen (Tmx) have shown contradictory experimental and clinical results.
  
  
  METHODS
  We examined the effects of a brief Tmx pretreatment on the chemosensitivity to 5-FU of two gastric carcinoma cell lines. One of these cell lines was ER(+) and the other ER(-). Tmx was administered for 24 hours before chemotherapy.
  
  
  RESULTS
  We observed a significant increase in the cytotoxic action of 5-FU in both gastric carcinoma cell lines in the order of 100-155%. This increase in 5-FU cytotoxicity was not mediated by either the ER cell status or through TGF-beta 1 secretion.
  
  
  CONCLUSIONS
  Brief Tmx pretreatment increases the chemosensitivity of gastric carcinoma cells to 5-FU in vitro.
authors.affiliation: Pinnacle Health Hospitals, Harrisburg, PA, USA. koullias@hotmail.com
authors.forename: George J
authors.initials: GJ
authors.lastname: Koullias
authors.forename: Charis I
authors.initials: CI
authors.lastname: Pratsinis
authors.forename: Dimitris P
authors.initials: DP
authors.lastname: Korkolis
authors.forename: Gregory
authors.initials: G
authors.lastname: Kouraklis
authors.forename: Stylianos A
authors.initials: SA
authors.lastname: Papadopoulos
authors.forename: Panagiotis S
authors.initials: PS
authors.lastname: Davaris
authors.forename: Basil Ch
authors.initials: BCh
authors.lastname: Golematis
mesh_terms: D030201:Activin Receptors, Type I; D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology*; D004334:Drug Administration Schedule; D019008:Drug Resistance, Neoplasm; D004958:Estradiol / Q000494:pharmacology; D005472:Fluorouracil / Q000494:pharmacology*; D006801:Humans; D009363:Neoplasm Proteins / Q000187:drug effects / Q000502:physiology; D017346:Protein Serine-Threonine Kinases; D011509:Proteoglycans; D000077293:Receptor, Transforming Growth Factor-beta Type I; D011960:Receptors, Estrogen / Q000187:drug effects / Q000502:physiology; D018125:Receptors, Transforming Growth Factor beta; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology*; D013629:Tamoxifen / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000378:metabolism; D053773:Transforming Growth Factor beta1; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
chemical_list: D000964:Antimetabolites, Antineoplastic; D018931:Antineoplastic Agents, Hormonal; D009363:Neoplasm Proteins; D011509:Proteoglycans; D011960:Receptors, Estrogen; D018125:Receptors, Transforming Growth Factor beta; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D013629:Tamoxifen; C071736:betaglycan; D004958:Estradiol; D017346:Protein Serine-Threonine Kinases; D030201:Activin Receptors, Type I; D000077293:Receptor, Transforming Growth Factor-beta Type I; D005472:Fluorouracil