title: Lack of demonstrable autocrine hedgehog signaling in human prostate cancer cell lines.
abstract: OBJECTIVE
  Several recent reports highlighted the role of hedgehog signaling in prostate cancer. However, the relative contributions of autocrine and paracrine hedgehog signaling to tumor growth and progression are unclear. Efforts to model autocrine signaling for drug development have been hampered by conflicting reports of the presence or absence of autocrine signaling in established human prostate cancer cell lines.
  
  
  METHODS
  We comprehensively characterized the expression of hedgehog pathway genes in the 3 prostate cancer cell lines LNCaP, PC3 and 22RV1 (American Type Culture Collection, Manassas, Virginia). We also examined their response to Shh ligand and to the hedgehog pathway inhibitor cyclopamine (Toronto Research Chemicals, Toronto, Ontario, Canada).
  
  
  RESULTS
  Expression of hedgehog ligand, patched and Gli1 in all 3 cell lines was lower than the expression level in normal human prostate tissue. All 3 cell lines showed hedgehog target gene activation when transfected with an activated form of Gli2 but none showed a detectable transcriptional response to hedgehog ligand or to transfection with an activated form of smoothened. Furthermore, treatment with the hedgehog pathway inhibitor cyclopamine did not inhibit hedgehog target gene expression in any of the 3 prostate cancer cell lines, although cyclopamine inhibited proliferation in culture.
  
  
  CONCLUSIONS
  LNCaP, PC3 and 22RV1 show no evidence of autocrine signaling by ligand dependent mechanisms and cyclopamine mediated inhibition of growth in culture occurs without of any discernible effect on canonical hedgehog pathway activity.
authors.affiliation: Department of Surgery and McArdle Laboratory for Cancer Research, University of Wisconsin, Madison, Wisconsin 53792, USA.
authors.forename: Jingxian
authors.initials: J
authors.lastname: Zhang
authors.forename: Robert
authors.initials: R
authors.lastname: Lipinski
authors.forename: Aubie
authors.initials: A
authors.lastname: Shaw
authors.forename: Jerry
authors.initials: J
authors.lastname: Gipp
authors.forename: Wade
authors.initials: W
authors.lastname: Bushman
mesh_terms: D019898:Autocrine Communication / Q000502:physiology*; D045744:Cell Line, Tumor; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D000072079:Patched Receptors; D011471:Prostatic Neoplasms / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000071676:Zinc Finger Protein GLI1
chemical_list: C400551:GLI1 protein, human; D053823:Hedgehog Proteins; C509246:IHH protein, human; D000072079:Patched Receptors; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; C509239:SHH protein, human; D014157:Transcription Factors; D000071676:Zinc Finger Protein GLI1