title: Key role of dual specificity kinase TTK in proliferation and survival of pancreatic cancer cells.
abstract: BACKGROUND
  Pancreatic ductal adenocarcinoma (PDAC) is among the most aggressive human malignancies with an overall 5-year survival rate of <5%. Despite significant advances in treatment of the disease during the past decade, the median survival rate (∼6 months) has hardly improved, warranting the need to identify novel targets for therapeutic approaches.
  
  
  METHODS
  Quantitative real time PCR, western blot analyses and immunohistochemical staining of tissue microarrays were used to analyse the expression of TTK gene in primary PDAC tissues and cell lines. To inhibit TTK kinase expression in a variety of pancreatic cancer cell lines, RNA interference was used. Functional roles of this kinase in the context of PDAC were studied using cell proliferation, viability and anchorage-independent growth assays. Western blotting, fluorescence-activated cell sorting analyses and fluorescence microscopy were used to gain mechanistic insight into the functional effects.
  
  
  CONCLUSIONS
  We show that the dual specificity kinase TTK (also known as Mps1), is strongly overexpressed in human PDAC. Functionally, cell proliferation was significantly attenuated following TTK knockdown, whereas apoptosis and necrosis rates were significantly increased. In addition, anchorage-independent growth, a hallmark of malignant transformation and metastatic potential, was strongly impaired in the absence of TTK gene function. Interestingly, immortalised normal pancreatic hTERT-HPNE cells were not affected by loss of TTK function. Mechanistically, these effects in cancer cells were associated with increased formation of micronuclei, suggesting that loss of TTK function in pancreatic cancer cells results in chromosomal instability and mitotic catastrophe. Taken together, our data show that TTK function is critical for growth and proliferation of pancreatic cancer cells, thus establishing this kinase as an interesting new target for novel therapeutic approaches in combating this malignancy.
authors.affiliation: Department of Medicine, Division of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Marburg, Germany.
authors.forename: B P
authors.initials: BP
authors.lastname: Kaistha
authors.affiliation: Department of Medicine, Division of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Marburg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Honstein
authors.affiliation: Department of Medicine, Division of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Marburg, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Müller
authors.affiliation: Department of Medicine, Division of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Marburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Bielak
authors.affiliation: Department of Medicine, Division of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Marburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Sauer
authors.affiliation: Department of Medicine, Division of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Marburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Kreider
authors.affiliation: Dipartimento ad Attività Integrata (DAI) di Patologia e Diagnostica, University of Verona, Verona, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Fassan
authors.affiliation: Dipartimento ad Attività Integrata (DAI) di Patologia e Diagnostica, University of Verona, Verona, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Scarpa
authors.affiliation: Department of Molecular Biology, Natural and Medical Sciences Institute of the University of Tübingen, Reutlingen, Tübingen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Schmees
authors.affiliation: Department of Molecular Biology, Natural and Medical Sciences Institute of the University of Tübingen, Reutlingen, Tübingen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Volkmer
authors.affiliation: Department of Medicine, Division of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Marburg, Germany.
authors.forename: T M
authors.initials: TM
authors.lastname: Gress
authors.affiliation: Department of Medicine, Division of Gastroenterology, Endocrinology and Metabolism, Philipps University Marburg, Marburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Buchholz
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D018797:Cell Cycle Proteins / Q000378:metabolism*; D049109:Cell Proliferation; D006801:Humans; D007124:Immunoenzyme Techniques; D010179:Pancreas / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046888:Tissue Array Analysis; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; D018797:Cell Cycle Proteins; D012333:RNA, Messenger; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C075840:TTK protein, human