title: Effect of estrogen, tamoxifen and epidermal growth factor on the transcriptional regulation of vascular endothelial growth factor in breast cancer cells.
abstract: BACKGROUND
  VEGF (Vascular Endothelial Growth Factor) is a key factor of angiogenesis and high tissue VEGF levels are related to a poor prognosis in breast cancer.
  
  
  METHODS
  By semi-quantitative RT-PCR, we determined the relative expressions of VEGF mRNA in MCF-7 (both ER-alpha+ and ER-beta+ (mainly ER-alpha+), PR+, bcl-2+, EGFR-) and MB-MDA-231 (only ER-beta+, PR-, EGFR-) breast cancer cells which were treated with estrogen, tamoxifen and EGF (Epidermal Growth Factor).
  
  
  RESULTS
  In MCF-7 cell lines, estrogen induced the expression of VEGF mRNA while tamoxifen reduced its expression. Estrogen and tamoxifen did not confer any significant effect on MB-MDA-231 cells and EGF showed no significant effect on MCF-7 or MB-MDA-231.
  
  
  CONCLUSIONS
  Reduced VEGF mRNA expression of MCF-7 cells treated with tamoxifen may be related to the antagonistic effect of tamoxifen on ER-positive breast cancer, and this antagonistic effect may be related to ER-alpha.
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea.
authors.forename: Jeong Eon
authors.initials: JE
authors.lastname: Lee
authors.forename: Ki-Wook
authors.initials: KW
authors.lastname: Chung
authors.forename: Wonshik
authors.initials: W
authors.lastname: Han
authors.forename: Sung-Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Seok Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Hyuk Jai
authors.initials: HJ
authors.lastname: Shin
authors.forename: Ji Yeoun
authors.initials: JY
authors.lastname: Bae
authors.forename: Dong-Young
authors.initials: DY
authors.lastname: Noh
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D003720:Densitometry; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013629:Tamoxifen / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D013629:Tamoxifen; D004958:Estradiol; D004815:Epidermal Growth Factor