title: Early epigenetic downregulation of WNK2 kinase during pancreatic ductal adenocarcinoma development.
abstract: Pancreatic ductal adenocarcinoma (PDAC) is usually incurable. Contrary to genetic mechanisms involved in PDAC pathogenesis, epigenetic alterations are ill defined. Here, we determine the contribution of epigenetically silenced genes to the development of PDAC. We analyzed enriched, highly methylated DNAs from PDACs, chronic pancreatitis (CP) and normal tissues using CpG island microarrays and identified WNK2 as a prominent candidate tumor suppressor gene being downregulated early in PDAC development. WNK2 was further investigated in tissue microarrays, methylation analysis of early pancreatic intraepithelial neoplasia (PanIN), mouse models for PDAC and pancreatitis, re-expression studies after demethylation, and cell growth assays using WNK2 overexpression. Demethylation assays confirmed the link between methylation and expression. WNK2 hypermethylation was higher in tumor than in surrounding inflamed tissues and was observed in PanIN lesions as well as in a PDAC mouse model. WNK2 mRNA and protein expressions were lower in PDAC and CP compared with normal tissues both in patients and mouse models. Overexpression of WNK2 led to reduced cell growth, and WNK2 expression in tissues correlated negatively with pERK1/2 expression, a downstream target of WNK2 responsible for cell proliferation. Downregulation of WNK2 by promoter hypermethylation occurs early in PDAC pathogenesis and may support tumor cell growth via the ERK-MAPK pathway.
authors.affiliation: Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Dutruel
authors.affiliation: Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Bergmann
authors.affiliation: Cancer Research Program, Garvan Institute of Medical Research, Darlinghurst, Australia.
authors.forename: I
authors.initials: I
authors.lastname: Rooman
authors.affiliation: Division of Biostatistics, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Zucknick
authors.affiliation: Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Weichenhan
authors.affiliation: Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Geiselhart
authors.affiliation: Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Kaffenberger
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: P S
authors.initials: PS
authors.lastname: Rachakonda
authors.affiliation: Functional Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Bauer
authors.affiliation: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Giese
authors.affiliation: Brain Tumor Research Center, Department of Neurosurgery, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California, USA.
authors.forename: C
authors.initials: C
authors.lastname: Hong
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Xie
authors.affiliation: Brain Tumor Research Center, Department of Neurosurgery, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Costello
authors.affiliation: Functional Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Hoheisel
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.affiliation: Department of Hematology and Oncology, University Hospital Regensburg, Regensburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Rehli
authors.affiliation: Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Schirmacher
authors.affiliation: Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Werner
authors.affiliation: Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Plass
authors.affiliation: Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Popanda
authors.affiliation: Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Schmezer
mesh_terms: D000818:Animals; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics*; D015536:Down-Regulation; D044127:Epigenesis, Genetic; D048049:Extracellular Signal-Regulated MAP Kinases / Q000096:biosynthesis; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D020411:Oligonucleotide Array Sequence Analysis; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology; D050500:Pancreatitis, Chronic / Q000235:genetics; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis
chemical_list: D012333:RNA, Messenger; C523482:WNK2 protein, human; D017346:Protein Serine-Threonine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases