title: Interleukin-6 induces neuroendocrine differentiation (NED) through suppression of RE-1 silencing transcription factor (REST).
abstract: BACKGROUND
  Paracrine interleukin-6 (IL-6) can mediate neuroendocrine (NE) features, including the acquisition of a neurite-like phenotype and growth arrest in prostate cancer cells. However, little is known about the mechanisms underlying neuroendocrine differentiation induced by IL-6.
  
  
  METHODS
  Immunoblotting was performed to determine the status of RE1-silencing transcription factor (REST) and of neuroendocrine markers such as Neuron-specific Enolase (NSE), chromogranin A and synaptophysin in LNCaP cells treated with IL-6. To further study the impact of REST-mediated repression on neuroendocrine differentiation (NED) in LNCaP cells, either wild-type REST or a dominant-positive form of REST, REST-VP16, in which both repressor domains of REST were replaced with the activation domain of the herpes simplex virus protein VP16, was introduced into LNCaP cells.
  
  
  RESULTS
  In this study, we show that REST is suppressed in IL-6-induced neuroendocrine differentiation in LNCaP cells. Overexpression of exogenous REST abrogated IL-6-induced NED in prostate cancer cells. Expression of the recombinant REST-VP16 fusion protein activated REST target genes and other neuronal differentiation genes and produced neuronal physiological properties. In addition, REST protein turnover was accelerated in IL-6 induced NE differentiated LNCaP cells via the ubiquitin-proteasome pathway, accompanied by a decrease in the expression of the deubiquitylase HAUSP, indicating that pathway(s) priming REST degradation may be involved in IL-6 induced NE differentiation.
  
  
  CONCLUSIONS
  These results demonstrate that REST functions as a major switch of IL-6 induced neuroendocrine differentiation in LNCaP cells.
authors.affiliation: Department of Urology, University of California Davis, Sacramento, California; Graduate Program in Pharmacology and Toxicology, University of California Davis, Sacramento, California.
authors.forename: Yezi
authors.initials: Y
authors.lastname: Zhu
authors.forename: Chengfei
authors.initials: C
authors.lastname: Liu
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Cui
authors.forename: Nagalakshmi
authors.initials: N
authors.lastname: Nadiminty
authors.forename: Wei
authors.initials: W
authors.lastname: Lou
authors.forename: Allen C
authors.initials: AC
authors.lastname: Gao
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D045744:Cell Line, Tumor; D053379:Chromogranin A / Q000378:metabolism; D015536:Down-Regulation; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology*; D008297:Male; D018358:Neuroendocrine Tumors / Q000378:metabolism* / Q000473:pathology*; D010641:Phenotype; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D016708:Synaptophysin / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism; D000099229:RE1-Silencing Transcription Factor
chemical_list: D014408:Biomarkers, Tumor; D053379:Chromogranin A; D015850:Interleukin-6; D010751:Phosphopyruvate Hydratase; D046988:Proteasome Endopeptidase Complex; D012097:Repressor Proteins; D016708:Synaptophysin; D025801:Ubiquitin; D000099229:RE1-Silencing Transcription Factor
keywords: REST; interleukin-6; neuroendocrine; prostate cancer