title: FOXA1 modulates EAF2 regulation of AR transcriptional activity, cell proliferation, and migration in prostate cancer cells.
abstract: BACKGROUND
  ELL-associated factor 2 (EAF2) is an androgen-regulated tumor suppressor in the prostate. However, the mechanisms underlying tumor suppressive function of EAF2 are still largely unknown. Identification of factors capable of modulating EAF2 function will help elucidate the mechanisms underlying EAF2 tumor suppressive function.
  
  
  METHODS
  Using eaf-1(the ortholog of EAF2) mutant C. elegans model, RNAi screen was used to identify factors on the basis of their knockdown to synergistically enhance the reduced fertility phenotype of the eaf-1 mutant C. elegans. In human cells, the interaction of EAF2 with FOXA1 and the effect of EAF2 on the FOXA1 protein levels were determined by co-immunoprecipitation and protein stability assay. The effect of EAF2 and/or FOXA1 knockdown on the expression of AR-target genes was determined by real-time RT-PCR and luciferase reporter assays. The effect of EAF2 and/or FOXA1 knockdown on LNCaP human prostate cancer cell proliferation and migration was tested using BrdU assay and transwell migration assay.
  
  
  RESULTS
  RNAi screen identified pha-4, the C. elegans ortholog of mammalian FOXA1, on the basis of its knockdown to synergistically enhance the reduced fertility phenotype of the eaf-1 mutant C. elegans causing sterility. EAF2 co-immunoprecipitated with FOXA1. EAF2 knockdown enhanced endogenous FOXA1 protein level, whereas transfected GFP-EAF2 down-regulated the FOXA1 protein. Also, EAF2 knockdown enhanced the expression of AR-target genes, cell proliferation, and migration in LNCaP cells. However, FOXA1 knockdown inhibited the effect of EAF2 knockdown on AR-target gene expression, cell proliferation, and migration in LNCaP cells, suggesting that FOXA1 can modulate EAF2 regulation of AR transcriptional activation, cell proliferation, and migration.
  
  
  CONCLUSIONS
  These findings suggest that regulation of the AR signaling pathway, cell proliferation, and migration through FOXA1 represents an important mechanism of EAF2 suppression of prostate carcinogenesis.
authors: Pathology Center, Shanghai First People's Hospital / Faculty of Basic Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
authors: Wenhuan
authors: W
authors: Guo
authors: Anne L
authors: AL
authors: Keener
authors: Yifeng
authors: Y
authors: Jing
authors: Liquan
authors: L
authors: Cai
authors: Junkui
authors: J
authors: Ai
authors: Jian
authors: J
authors: Zhang
authors: A L
authors: AL
authors: Fisher
authors: Guohui
authors: G
authors: Fu
authors: Zhou
authors: Z
authors: Wang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D017173:Caenorhabditis elegans; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000502:physiology; D015536:Down-Regulation; D051541:Hepatocyte Nuclear Factor 3-alpha / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D008297:Male; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D034622:RNA Interference / Q000502:physiology; D011944:Receptors, Androgen / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection / Q000379:methods
chemical_list: C410798:AR protein, human; C472771:EAF2 protein, human; C496499:FOXA1 protein, human; D051541:Hepatocyte Nuclear Factor 3-alpha; D011944:Receptors, Androgen; D014157:Transcription Factors
keywords: EAF2; FOXA1; androgen receptor; prostate cancer