title: Snail transcription factor regulates neuroendocrine differentiation in LNCaP prostate cancer cells.
abstract: BACKGROUND
  Snail transcription factor induces epithelial-mesenchymal transition (EMT) via decreased cell adhesion-associated molecules like E-cadherin, and increased mesenchymal markers like vimentin. We previously established Snail-mediated EMT model utilizing androgen-dependent LNCaP cells. These cells express increased vimentin protein and relocalization of E-cadherin from the cell membrane to the cytosol. Interestingly, Snail transfection in LNCaP cells resulted in cells acquiring a neuroendocrine (NE)-like morphology with long neurite-like processes.
  
  
  METHODS
  We tested for expression of NE markers neuron-specific enolase (NSE) and chromogranin A (CgA) by Western blot analysis, and performed proliferation assays to test for paracrine cell proliferation.
  
  
  RESULTS
  LNCaP cells transfected with Snail displayed increase in the NE markers, NSE and CgA as well as translocation of androgen receptor (AR) to the nucleus. LNCaP C-33 cells that have been previously published as a neuroendocrine differentiation (NED) model exhibited increased expression levels of Snail protein as compared to LNCaP parental cells. Functionally, conditioned medium from the LNCaP-Snail transfected cells increased proliferation of parental LNCaP and PC-3 cells, which could be abrogated by NSE/CgA siRNA. Additionally, NED in LNCaP-C33 cells or that induced in parental LNCaP cells by serum starvation could be inhibited by knockdown of Snail with siRNA.
  
  
  CONCLUSIONS
  Overall our data provide evidence that Snail transcription factor may promote tumor aggressiveness in the LNCaP cells through multiple processes; induction of EMT may be required to promote migration, while NED may promote tumor proliferation by a paracrine mechanism. Therefore, therapeutic targeting of Snail may prove beneficial in not only abrogating EMT but also NED.
authors.affiliation: Department of Biological Sciences, Clark Atlanta University, Atlanta, Georgia 30314, USA.
authors.forename: Danielle
authors.initials: D
authors.lastname: McKeithen
authors.forename: Tisheeka
authors.initials: T
authors.lastname: Graham
authors.forename: Leland W K
authors.initials: LW
authors.lastname: Chung
authors.forename: Valerie
authors.initials: V
authors.lastname: Odero-Marah
mesh_terms: D000728:Androgens / Q000378:metabolism; D015153:Blotting, Western; D002454:Cell Differentiation / Q000502:physiology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002478:Cells, Cultured; D053379:Chromogranin A / Q000235:genetics / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D010751:Phosphopyruvate Hydratase / Q000235:genetics / Q000378:metabolism*; D011467:Prostate / Q000378:metabolism*; D034741:RNA, Small Interfering; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071250:Snail Family Transcription Factors; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D000728:Androgens; D053379:Chromogranin A; D034741:RNA, Small Interfering; D011944:Receptors, Androgen; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D010751:Phosphopyruvate Hydratase