title: Dasatinib blocks transcriptional and promigratory responses to transforming growth factor-beta in pancreatic adenocarcinoma cells through inhibition of Smad signalling: implications for in vivo mode of action.
abstract: BACKGROUND
  We have previously shown in pancreatic ductal adenocarcinoma (PDAC) cells that the SRC inhibitors PP2 and PP1 effectively inhibited TGF-β1-mediated cellular responses by blocking the kinase function of the TGF-β type I receptor ALK5 rather than SRC. Here, we investigated the ability of the clinically utilised SRC/ABL inhibitor dasatinib to mimic the PP2/PP1 effect.
  
  
  METHODS
  The effect of dasatinib on TGF-β1-dependent Smad2/3 phosphorylation, general transcriptional activity, gene expression, cell motility, and the generation of tumour stem cells was measured in Panc-1 and Colo-357 cells using immunoblotting, reporter gene assays, RT-PCR, impedance-based real-time measurement of cell migration, and colony formation assays, respectively.
  
  
  RESULTS
  In both PDAC cell lines, dasatinib effectively blocked TGF-β1-induced Smad phosphorylation, activity of 3TPlux and pCAGA(12)-luc reporter genes, cell migration, and expression of individual TGF-β1 target genes associated with epithelial-mesenchymal transition and invasion. Moreover, dasatinib strongly interfered with the TGF-β1-induced generation of tumour stem cells as demonstrated by gene expression analysis and single cell colony formation. Dasatinib also inhibited the high constitutive migratory activity conferred on Panc-1 cells by ectopic expression of kinase-active ALK5.
  
  
  CONCLUSIONS
  Our data suggest that the clinical efficiency of dasatinib may in part be due to cross-inhibition of tumour-promoting TGF-β signalling. Dasatinib may be useful as a dual TGF-β/SRC inhibitor in experimental and clinical therapeutics to prevent metastatic spread in late-stage PDAC and other tumours.
authors.affiliation: First Department of Medicine, UKSH, Campus Lübeck, 23538, Lübeck, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Bartscht
authors.affiliation: First Department of Medicine, UKSH, Campus Lübeck, 23538, Lübeck, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Rosien
authors.affiliation: Department of Radiation Oncology, UKSH, Campus Lübeck, D-23538, Lübeck, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Rades
authors.affiliation: Department of General, Visceral and Vascular Surgery, Jena University Hospital, D-07747, Jena, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Kaufmann
authors.affiliation: First Department of Medicine, UKSH, Campus Lübeck, 23538, Lübeck, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Biersack
authors.affiliation: First Department of Medicine, UKSH, Campus Lübeck, 23538, Lübeck, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Lehnert
authors.affiliation: First Department of Medicine, UKSH, Campus Lübeck, 23538, Lübeck, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Gieseler
authors.affiliation: First Department of Medicine, UKSH, Campus Lübeck, 23538, Lübeck, Germany. hendrik.ungefroren@uksh.de.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Ungefroren
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D021441:Carcinoma, Pancreatic Ductal / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D000069439:Dasatinib / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D058750:Epithelial-Mesenchymal Transition; D006801:Humans; D009361:Neoplasm Invasiveness; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D015398:Signal Transduction; D051899:Smad2 Protein / Q000378:metabolism; D051900:Smad3 Protein / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D053773:Transforming Growth Factor beta1 / Q000502:physiology*
chemical_list: D000970:Antineoplastic Agents; D018125:Receptors, Transforming Growth Factor beta; C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; D051899:Smad2 Protein; D051900:Smad3 Protein; D053773:Transforming Growth Factor beta1; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human; D000069439:Dasatinib