title: Human ASH-1 promotes neuroendocrine differentiation in androgen deprivation conditions and interferes with androgen responsiveness in prostate cancer cells.
abstract: BACKGROUND
  Neuroendocrine differentiation in prostate cancer is a dynamic process associated to the onset of hormone-refractory disease in vivo. The molecular mechanisms underlying this process are poorly recognized. Our study aimed at testing in vitro the role of hASH-1, a transcription factor implicated in neuroendocrine differentiation, in the onset of neuroendocrine phenotype in prostate cancer cells.
  
  
  METHODS
  Androgen sensitive LNCAP, androgen insensitive PC-3, and three immortalized prostate cancer cell lines were cultured in standard and androgen deprivation conditions. Expression of hASH-1 was modulated by either specific lentiviral transduction or shRNA interference. Inhibitors of WNT-11, a WNT family member associated to the development of neuroendocrine differentiation in prostate cancer, were also used. Cell viability was measured using the MTS method. Neuroendocrine phenotype was assessed by morphology, immunohistochemistry and real time PCR for several neuroendocrine markers.
  
  
  RESULTS
  hASH-1 was up-modulated by androgen deprivation in LNCaP cells and in androgen-sensitive immortalized prostate cancer cells, and associated with the onset of a neuroendocrine phenotype. Silencing of hASH-1 prevented neuroendocrine differentiation, as did also the selective interference with the WNT-11 pathway. Moreover, hASH-1 over-expression in LNCaP cells was sufficient to promote neuroendocrine differentiation and increased cell viability at basal and androgen-deprived growth conditions.
  
  
  CONCLUSIONS
  In summary, the present data support previous evidence that the acquisition of a neuroendocrine phenotype is linked to androgen responsiveness profiles and suggest a pivotal role of hASH-1 transcription factor, whose activity might be explored as a potential therapeutic target in prostate cancer, with special reference to hormone refractory disease.
authors: Department of Oncology at San Luigi Hospital, University of Turin, Orbassano, Turin, Italy.
authors: Ida
authors: I
authors: Rapa
authors: Marco
authors: M
authors: Volante
authors: Cristina
authors: C
authors: Migliore
authors: Antonella
authors: A
authors: Farsetti
authors: Alfredo
authors: A
authors: Berruti
authors: Giorgio
authors: G
authors: Vittorio Scagliotti
authors: Silvia
authors: S
authors: Giordano
authors: Mauro
authors: M
authors: Papotti
mesh_terms: D000728:Androgens / Q000172:deficiency* / Q000494:pharmacology; D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D006801:Humans; D008297:Male; D009490:Neurosecretory Systems / Q000187:drug effects / Q000502:physiology*; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology*
chemical_list: D000728:Androgens; D051792:Basic Helix-Loop-Helix Proteins; C065500:ASCL1 protein, human