title: Planar cell polarity gene expression correlates with tumor cell viability and prognostic outcome in neuroblastoma.
abstract: BACKGROUND
  The non-canonical Wnt/Planar cell polarity (PCP) signaling pathway is a major player in cell migration during embryonal development and has recently been implicated in tumorigenesis.
  
  
  METHODS
  Transfections with cDNA plasmids or siRNA were used to increase and suppress Prickle1 and Vangl2 expression in neuroblastoma cells and in non-tumorigenic cells. Cell viability was measured by trypan blue exclusion and protein expression was determined with western blotting. Transcriptional activity was studied with luciferase reporter assay and mRNA expression with real-time RT-PCR. Immunofluorescence stainings were used to study the effects of Vangl2 overexpression in non-tumorigenic embryonic cells. Statistical significance was tested with t-test or one-way ANOVA.
  
  
  RESULTS
  Here we show that high expression of the PCP core genes Prickle1 and Vangl2 is associated with low-risk neuroblastoma, suppression of neuroblastoma cell growth and decreased Wnt/β-catenin signaling. Inhibition of Rho-associated kinases (ROCKs) that are important in mediating non-canonical Wnt signaling resulted in increased expression of Prickle1 and inhibition of β-catenin activity in neuroblastoma cells. In contrast, overexpression of Vangl2 in MYC immortalized neural stem cells induced accumulation of active β-catenin and decreased the neural differentiation marker Tuj1. Similarly, genetically modified mice with forced overexpression of Vangl2 in nestin-positive cells showed decreased Tuj1 differentiation marker during embryonal development.
  
  
  CONCLUSIONS
  Our experimental data demonstrate that high expression of Prickle1 and Vangl2 reduce the growth of neuroblastoma cells and indicate different roles of PCP proteins in tumorigenic cells compared to normal cells. These results suggest that the activity of the non-canonical Wnt/PCP signaling pathway is important for neuroblastoma development and that manipulation of the Wnt/PCP pathway provides a possible therapy for neuroblastoma.
authors.affiliation: Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Astrid Lindgren Children's Hospital Q6:05, SE-171 76, Stockholm, Sweden. cecilia.dyberg@ki.se.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Dyberg
authors.affiliation: Neonatal Research Unit, Department of Women's and Children's Health, Astrid Lindgren Children's hospital, Q2:07, Karolinska Institutet, SE-171 76, Stockholm, Sweden.|Academic Primary Health Care Center, TioHundra AB, Box 905, SE-761 29, Norrtälje, Sweden.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Papachristou
authors.affiliation: Department of Pediatrics, University-Hospital of Northern-Norway (UNN), 9037, Tromsø, Norway.
authors.forename: Bjørn Helge
authors.initials: BH
authors.lastname: Haug
authors.affiliation: Neonatal Research Unit, Department of Women's and Children's Health, Astrid Lindgren Children's hospital, Q2:07, Karolinska Institutet, SE-171 76, Stockholm, Sweden.
authors.forename: Hugo
authors.initials: H
authors.lastname: Lagercrantz
authors.affiliation: Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Astrid Lindgren Children's Hospital Q6:05, SE-171 76, Stockholm, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Kogner
authors.affiliation: Neonatal Research Unit, Department of Women's and Children's Health, Astrid Lindgren Children's hospital, Q2:07, Karolinska Institutet, SE-171 76, Stockholm, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ringstedt
authors.affiliation: Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Astrid Lindgren Children's Hospital Q6:05, SE-171 76, Stockholm, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Wickström
authors.affiliation: Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Astrid Lindgren Children's Hospital Q6:05, SE-171 76, Stockholm, Sweden.
authors.forename: John Inge
authors.initials: JI
authors.lastname: Johnsen
mesh_terms: D000818:Animals; D063646:Carcinogenesis / Q000235:genetics*; D002465:Cell Movement / Q000235:genetics; D016764:Cell Polarity / Q000235:genetics; D002470:Cell Survival / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000096:biosynthesis* / Q000235:genetics; D060588:LIM Domain Proteins / Q000096:biosynthesis* / Q000235:genetics; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D009447:Neuroblastoma / Q000235:genetics* / Q000473:pathology; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis* / Q000235:genetics; D060449:Wnt Signaling Pathway / Q000235:genetics; D051176:beta Catenin / Q000235:genetics; D054460:rho-Associated Kinases / Q000235:genetics
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; D008565:Membrane Proteins; C515173:PRICKLE1 protein, human; D025521:Tumor Suppressor Proteins; C468513:VANGL2 protein, human; D051176:beta Catenin; D054460:rho-Associated Kinases
keywords: Neuroblastoma; Prickle1; Vangl2; Wnt/PCP pathway