title: A rat endometrial cell line (R1-49E1) expressing estrogen receptor-alpha regulated by the tet-off system.
abstract: BACKGROUND
  Estrogens exert profound effects on target tissues. These effects are mediated by two estrogen receptors (ER(alpha) and ER(beta)) that bind to specific DNA sequences in estrogen-dependent genes. Other molecules such as growth factors, transcription factors and some oncoproteins might interact with the estrogen receptors and thus regulate the transcription of these genes. Currently there is no adequate cellular model to study these interactions.
  
  
  METHODS
  We transfected the human wild-type ER(alpha) to an ER-negative rat epithelial endometrial cell line (Rentr01) using a tetracycline-regulated gene expression system. The exogenous receptor was correctly translated, had an appropriate hormone-binding affinity, and bound well to estrogen response elements containing DNA.
  
  
  RESULTS
  We obtained a new stable cell line that is ER(beta) negative but ER(alpha) positive (R1-49E1). The expression of receptor alpha can be regulated in a dose-response manner by addition of tetracycline in the culture medium. Estradiol treatment of ER(alpha)-containing cells apparently diminished cellular proliferation, and the exogenous receptor can induce the transcription of the endogenous progesterone receptor isoform B (PgR-B) gene.
  
  
  CONCLUSIONS
  This epithelial cellular model may be useful to study the interaction between estrogens and other cell signaling pathways in epithelial endometrial cell physiology.
authors.affiliation: Department of Biochemistry and Molecular Biology; National Institute of Public Health, Cuernavaca, Morelos, Mexico.
authors.forename: Ivone
authors.initials: I
authors.lastname: Castro
authors.forename: Joel
authors.initials: J
authors.lastname: Arias
authors.forename: Hector
authors.initials: H
authors.lastname: Flores
authors.forename: Arturo
authors.initials: A
authors.lastname: Barrón
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D003470:Culture Media / Q000494:pharmacology; D004247:DNA / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004717:Endometrium / Q000166:cytology*; D047628:Estrogen Receptor alpha / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000378:metabolism; D005260:Female; D017930:Genes, Reporter; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D041681:NIH 3T3 Cells; D011485:Protein Binding; D051381:Rats; D011980:Receptors, Progesterone / Q000378:metabolism; D020218:Response Elements; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013752:Tetracycline / Q000494:pharmacology*; D013997:Time Factors; D014162:Transfection
chemical_list: D003470:Culture Media; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D011980:Receptors, Progesterone; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase; D013752:Tetracycline