title: Assessment of estrogenic activity of natural compounds using improved E-screen assay.
abstract: OBJECTIVE
  To improve E-screen assay and make it more accurate to screen estrogenic compounds.
  
  
  METHODS
  Estrogen receptor antisense RNA expression plasmid (pCASER) was constructed and introduced into MCF-7 with lipofectAMINE(TM), and positive clones were screened out with G418. PCR amplification was employed to identify whether estrogen receptor (ER) cDNA fragment had been inserted into MCF-7 cell genomes. Western blot was applied to detect the expression of ER. Cell growth was determined by MTT assay.
  
  
  RESULTS
  One ER antisense clone (MTASER) had been screened out. The effects of 17beta-estradiol, genistein, droloxifen, miyabenol C, and kobophenol A on MCF-7 were stronger than those effects on MTASER. Epidermal growth factor (EGF) had equivalent stimulatory effects on the proliferation of MCF-7 and MTASER.
  
  
  CONCLUSIONS
  The improved E-screen assay could screen estrogenic compounds more accurately than original E-screen assay did.
authors.affiliation: Department of Molecular Genetics, School of Medicine, Fudan Univ ersity, Shanghai 200032, China. ytian@sina.com
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Tian
authors.forename: Chang-Qi
authors.initials: CQ
authors.lastname: Hu
authors.forename: Guang
authors.initials: G
authors.lastname: Xu
authors.forename: Hou-Yan
authors.initials: HY
authors.lastname: Song
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D004958:Estradiol / Q000494:pharmacology*; D004968:Estrogens, Non-Steroidal / Q000494:pharmacology*; D005260:Female; D019833:Genistein / Q000494:pharmacology*; D006801:Humans; D007529:Isoflavones; D048789:Phytoestrogens; D028321:Plant Preparations; D016372:RNA, Antisense / Q000235:genetics / Q000494:pharmacology; D011960:Receptors, Estrogen / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D004968:Estrogens, Non-Steroidal; D007529:Isoflavones; D048789:Phytoestrogens; D028321:Plant Preparations; D016372:RNA, Antisense; D011960:Receptors, Estrogen; D004958:Estradiol; D019833:Genistein