title: Activation of β-catenin signalling by TFF1 loss promotes cell proliferation and gastric tumorigenesis.
abstract: OBJECTIVE
  In this study, we investigated the role of Trefoil factor 1 (TFF1) in regulating cell proliferation and tumour development through β-catenin signalling using in vivo and in vitro models of gastric tumorigenesis.
  
  
  METHODS
  Tff1-knockout (Tff1-KO) mice, immunohistochemistry, luciferase reporter, qRT-PCR, immunoblot, and phosphatase assays were used to examine the role of TFF1 on β-catenin signalling pathway.
  
  
  RESULTS
  Nuclear localisation of β-catenin with transcriptional upregulation of its target genes, c-Myc and Ccnd1, was detected in hyperplastic tissue at an early age of 4-6 weeks and maintained during all stages of gastric tumorigenesis in the Tff1-KO mice. The reconstitution of TFF1 or TFF1 conditioned media significantly inhibited the β-catenin/T-cell factor (TCF) transcription activity in MKN28 gastric cancer cells. In agreement with these results, we detected a reduction in the levels of nuclear β-catenin with downregulation of c-MYC and CCND1 mRNA. Analysis of signalling molecules upstream of β-catenin revealed a decrease in phosphorylated glycogen synthase kinase 3β (p-GSK3β) (Ser9) and p-AKT (Ser473) protein levels following the reconstitution of TFF1 expression; this was consistent with the increase of p-β-catenin (Ser33/37/Thr41) and decrease of p-β-catenin (Ser552). This TFF1-induced reduction in phosphorylation of GSK3β, and AKT was dependent on protein phosphatase 2A (PP2A) activity. The treatment with okadaic acid or knockdown of PP2A abrogated these effects. Consistent with the mouse data, we observed loss of TFF1 and an increase in nuclear localisation of β-catenin in stages of human gastric tumorigenesis.
  
  
  CONCLUSIONS
  Our data indicate that loss of TFF1 promotes β-catenin activation and gastric tumorigenesis through regulation of PP2A, a major regulator of AKT-GSK3β signalling.
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Soutto
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA.
authors.forename: DunFa
authors.initials: D
authors.lastname: Peng
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Katsha
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Maria Blanca
authors.initials: MB
authors.lastname: Piazuelo
authors.affiliation: Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Mary Kay
authors.initials: MK
authors.lastname: Washington
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Abbes
authors.initials: A
authors.lastname: Belkhiri
authors.affiliation: Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Pelayo
authors.initials: P
authors.lastname: Correa
authors.affiliation: Department of Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, Tennessee, USA Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Wael
authors.initials: W
authors.lastname: El-Rifai
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation / Q000502:physiology; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006131:Growth Inhibitors / Q000502:physiology*; D007150:Immunohistochemistry; D051379:Mice; D018345:Mice, Knockout; D010455:Peptides / Q000502:physiology*; D054648:Protein Phosphatase 2 / Q000502:physiology*; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology*; D013274:Stomach Neoplasms / Q000473:pathology* / Q000503:physiopathology*; D015533:Transcriptional Activation / Q000502:physiology; D000071163:Trefoil Factor-1; D051176:beta Catenin / Q000502:physiology*
chemical_list: D006131:Growth Inhibitors; D010455:Peptides; C472724:Tff1 protein, mouse; D000071163:Trefoil Factor-1; D051176:beta Catenin; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3; D054648:Protein Phosphatase 2
keywords: GASTRIC CANCER; TREFOIL FACTORS
references.citation: Histopathology. 2006 Dec;49(6):612-21
references.pmid: 17163846
references.citation: Science. 1997 Mar 21;275(5307):1787-90
references.pmid: 9065402
references.citation: J Clin Invest. 2011 May;121(5):1753-67
references.pmid: 21490402
references.citation: Curr Opin Genet Dev. 1999 Feb;9(1):15-21
references.pmid: 10072352
references.citation: Cancer Res. 2007 May 1;67(9):4079-87
references.pmid: 17483318
references.citation: CA Cancer J Clin. 2005 Mar-Apr;55(2):74-108
references.pmid: 15761078
references.citation: Genes Dev. 2000 Aug 1;14(15):1837-51
references.pmid: 10921899
references.citation: FASEB J. 2002 Apr;16(6):592-4
references.pmid: 11919164
references.citation: Science. 1988 Aug 5;241(4866):705-8
references.pmid: 3041593
references.citation: J Biol Chem. 2007 Apr 13;282(15):11221-9
references.pmid: 17287208
references.citation: Carcinogenesis. 2012 Sep;33(9):1726-35
references.pmid: 22581840
references.citation: Gastroenterology. 2011 Mar;140(3):879-91
references.pmid: 21111741
references.citation: Science. 1992 Aug 28;257(5074):1261-4
references.pmid: 1325671
references.citation: Cell Mol Life Sci. 2005 Dec;62(24):2956-73
references.pmid: 16374584
references.citation: Science. 1996 Oct 11;274(5285):259-62
references.pmid: 8824193
references.citation: Nat Rev Cancer. 2010 Jun;10(6):403-14
references.pmid: 20495574
references.citation: Lab Invest. 2002 Oct;82(10):1319-26
references.pmid: 12379766
references.citation: Mol Cancer. 2011 Mar 29;10:32
references.pmid: 21447180
references.citation: Clin Cancer Res. 2004 Feb 15;10(4):1401-8
references.pmid: 14977843
references.citation: Cancer Lett. 2013 Jul 10;335(1):9-18
references.pmid: 23454242
references.citation: Cell. 2001 Jun 15;105(6):721-32
references.pmid: 11440715
references.citation: Eur Rev Med Pharmacol Sci. 2010 Apr;14(4):309-14
references.pmid: 20496540
references.citation: J Biol Chem. 2009 Aug 21;284(34):22649-56
references.pmid: 19556239
references.citation: Cytokine Growth Factor Rev. 2000 Dec;11(4):273-82
references.pmid: 10959075
references.citation: Biochem J. 2007 Apr 15;403(2):235-42
references.pmid: 17212588
references.citation: Lab Invest. 2001 Mar;81(3):397-408
references.pmid: 11310832
references.citation: Oncogene. 2011 Jul 21;30(29):3261-73
references.pmid: 21358676
references.citation: EMBO J. 1997 Jul 1;16(13):3797-804
references.pmid: 9233789
references.citation: Cancer Res. 2006 Feb 1;66(3):1346-53
references.pmid: 16452188
references.citation: Crit Rev Oncog. 2007 Nov;13(2):93-158
references.pmid: 18197790
references.citation: Cell Mol Life Sci. 1997 Dec;53(11-12):888-903
references.pmid: 9447240
references.citation: J Biol Chem. 2006 Apr 14;281(15):9971-6
references.pmid: 16476742
references.citation: Pathol Oncol Res. 2010 Jun;16(2):253-7
references.pmid: 20182836
references.citation: Dev Dyn. 2010 Jan;239(1):34-44
references.pmid: 19623618
references.citation: Int J Cancer. 2010 Dec 15;127(12):2893-917
references.pmid: 21351269
references.citation: Science. 1996 May 17;272(5264):1023-6
references.pmid: 8638126
references.citation: Gastroenterology. 2000 Sep;119(3):691-8
references.pmid: 10982763
references.citation: Cell Signal. 2008 Apr;20(4):581-9
references.pmid: 18023328
references.citation: J Biol Chem. 2013 May 10;288(19):13215-24
references.pmid: 23536185
references.citation: Am J Pathol. 1996 Jan;148(1):39-46
references.pmid: 8546224