title: Evaluation of the tetracycline-repressible transactivator system for inducible gene expression in human prostate cancer cell lines.
abstract: BACKGROUND
  Studies of genes that may inhibit growth or induce death of cells are facilitated greatly by tightly controlled expression of those genes. A promising system for control of transgene expression over a wide range is the tetracycline-repressible transactivator (tTA) system developed by Gossen and Bujard [Proc Natl Acad Sci USA 1992;89:5547-5551]. We investigated the effectiveness of this system in three well-established human prostate cancer cell lines.
  
  
  METHODS
  LNCaP, PC-3, and Tsu-Pr1 cells were transfected with a vector coding for the tTA protein and/or a luciferase reporter vector, and luciferase activity was measured in the presence and absence of tetracycline or the tTA protein.
  
  
  RESULTS
  In the absence of tetracycline, the tTA system yielded high levels of luciferase activity in all three cell lines. Background luciferase activity in the presence of tetracycline was nearly undetectable in LNCaP cells, moderate in Tsu-Pr1 cells, and more than 20-fold higher in PC-3 than in Tsu-Pr1 cells. Similar background activity was observed in Tsu-Pr1 and PC-3 cells, even in the absence of the transactivator protein.
  
  
  CONCLUSIONS
  The tTA system should be useful for stable transfection of cytotoxic transgenes in LNCaP cells and for control of transgene expression over a wide range in Tsu-Pr1 and PC-3 cells.
authors.affiliation: Urologic Oncology Research Laboratory, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Gschwend
authors.forename: W R
authors.initials: WR
authors.lastname: Fair
authors.forename: C T
authors.initials: CT
authors.lastname: Powell
mesh_terms: D002460:Cell Line; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008297:Male; D010957:Plasmids / Q000187:drug effects / Q000502:physiology; D011467:Prostate / Q000166:cytology / Q000201:enzymology / Q000502:physiology*; D011471:Prostatic Neoplasms / Q000503:physiopathology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D012333:RNA, Messenger; D013752:Tetracycline / Q000494:pharmacology*; D015534:Trans-Activators / Q000187:drug effects* / Q000502:physiology*; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D015534:Trans-Activators; D008156:Luciferases; D013752:Tetracycline