title: Prostate-derived factor as a paracrine and autocrine factor for the proliferation of androgen receptor-positive human prostate cancer cells.
abstract: BACKGROUND
  The expression of prostate-derived factor (PDF) is significantly elevated in human prostate tumors. We investigate the functional role and signaling of PDF in androgen receptor (AR)-positive human prostate cancer cells.
  
  
  METHODS
  Transient or stable expression of PDF by cDNA transfection, antisense-mediated gene silencing, media conditioned by PDF-elevated cells, and antibody (Ab) neutralization were employed.
  
  
  RESULTS
  Elevated endogenous and exogenous expression of PDF and treatment of PDF-enriched media were associated with increased proliferation and clonogenic growth of the cells. On the contrary, knockdown of PDF or addition of PDF neutralizing Ab resulted in diminished proliferation and reduced anchorage-independent growth. Further, ERK1/2 and p90RSK, but not Smad2/3, were activated in PDF-elevated cells as well as in cells treated with PDF-enriched media, while inhibition of ERK1/2 decreased the growth of those cells.
  
  
  CONCLUSIONS
  PDF promotes AR-positive prostate tumor progression through upregulating cell proliferation via ERK1/2 signal pathway.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA.
authors.forename: Siu-Ju
authors.initials: SJ
authors.lastname: Chen
authors.forename: Dev
authors.initials: D
authors.lastname: Karan
authors.forename: Sonny L
authors.initials: SL
authors.lastname: Johansson
authors.forename: Fen-Fen
authors.initials: FF
authors.lastname: Lin
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Zeckser
authors.forename: Ajay P
authors.initials: AP
authors.lastname: Singh
authors.forename: Surinder K
authors.initials: SK
authors.lastname: Batra
authors.forename: Ming-Fong
authors.initials: MF
authors.lastname: Lin
mesh_terms: D015153:Blotting, Western; D019485:Bone Morphogenetic Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D020868:Gene Silencing; D055436:Growth Differentiation Factor 15; D006801:Humans; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011944:Receptors, Androgen / Q000096:biosynthesis*; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: C410798:AR protein, human; D019485:Bone Morphogenetic Proteins; C526140:GDF15 protein, human; D055436:Growth Differentiation Factor 15; D011944:Receptors, Androgen; D016212:Transforming Growth Factor beta; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3