title: Eukaryotic elongation factor 2 is a prognostic marker and its kinase a potential therapeutic target in HCC.
abstract: Hepatocellular carcinoma is a cancer with increasing incidence and largely refractory to current anticancer drugs. Since Sorafenib, a multikinase inhibitor has shown modest efficacy in advanced hepatocellular carcinoma additional treatments are highly needed. Protein phosphorylation via kinases is an important post-translational modification to regulate cell homeostasis including proliferation and apoptosis. Therefore kinases are valuable targets in cancer therapy. To this end we performed 2D differential gel electrophoresis and mass spectrometry analysis of phosphoprotein-enriched lysates of tumor and corresponding non-tumorous liver samples to detect differentially abundant phosphoproteins to screen for novel kinases as potential drug targets. We identified 34 differentially abundant proteins in phosphoprotein enriched lysates. Expression and distribution of the candidate protein eEF2 and its phosphorylated isoform was validated immunohistochemically on 78 hepatocellular carcinoma and non-tumorous tissue samples. Validation showed that total eEF2 and phosphorylated eEF2 at threonine 56 are prognostic markers for overall survival of HCC-patients. The activity of the regulating eEF2 kinase, compared between tumor and non-tumorous tissue lysates by in vitro kinase assays, is more than four times higher in tumor tissues. Functional analyzes regarding eEF2 kinase were performed in JHH5 cells with CRISPR/Cas9 mediated eEF2 kinase knock out. Proliferation and growth is decreased in eEF2 kinase knock out cells.
  
  
  CONCLUSIONS
  eEF2 and phosphorylated eEF2 are prognostic markers for survival of hepatocellular carcinoma patients and the regulating eEF2 kinase is a potential drug target for tumor therapy.
authors.affiliation: Institute of Pathology, University of Duisburg-Essen, Essen, Germany.|Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Leona L
authors.initials: LL
authors.lastname: Pott
authors.affiliation: Institute of Pathology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Hagemann
authors.affiliation: Institute of Pathology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Reis
authors.affiliation: Institute of Pharmacology, University of Wuerzburg, Wuerzburg, Germany.|Leibniz-Institut für Analytische Wissenschaften -ISAS-e.V., Dortmund, Germany.|West German Heart and Vascular Center, University of Duisburg-Essen, Essen, Germany.
authors.forename: Kristina
authors.initials: K
authors.lastname: Lorenz
authors.affiliation: Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Thilo
authors.initials: T
authors.lastname: Bracht
authors.affiliation: Institute of Pathology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Herold
authors.affiliation: Transgenic Animal and Genetic Engineering Models (TRAM), Westphalian Wilhelms University, Muenster, Germany.
authors.forename: Boris V
authors.initials: BV
authors.lastname: Skryabin
authors.affiliation: Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Dominik A
authors.initials: DA
authors.lastname: Megger
authors.affiliation: Institute of Pathology, University of Duisburg-Essen, Essen, Germany.|Department of Gastroenterology and Hepatology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Kälsch
authors.affiliation: Department of General, Visceral and Transplantation Surgery, University of Duisburg-Essen, Essen, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Weber
authors.affiliation: Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sitek
authors.affiliation: Institute of Pathology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Hideo A
authors.initials: HA
authors.lastname: Baba
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D054736:Elongation Factor 2 Kinase / Q000378:metabolism*; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D058990:Molecular Targeted Therapy; D011379:Prognosis; D015398:Signal Transduction
chemical_list: C517689:EEF2K protein, human; D054736:Elongation Factor 2 Kinase
keywords: eEF2; eEF2 kinase; hepatocellular carcinoma; prognosis