title: ER stress protein AGR2 precedes and is involved in the regulation of pancreatic cancer initiation.
abstract: The mechanisms of initiation of pancreatic ductal adenocarcinoma (PDAC) are still largely unknown. In the present study, we analysed the role of anterior gradient-2 (AGR2) in the earliest stages of pancreatic neoplasia. Immunohistochemical analysis of chronic pancreatitis (CP) and peritumoral areas in PDAC tissues showed that AGR2 was present in tubular complexes (TC) and early pancreatic intraepithelial neoplasia (PanINs). Moreover, AGR2 was also found in discrete subpopulations of non-transformed cells neighbouring these pre-neoplastic lesions. In primary cells derived from human patient-derived xenograft (PDX) model, flow-cytometry revealed that AGR2 was overexpressed in pancreatic cancer stem cells (CSC) compared with non-stem cancer cells. In LSL-KrasG12D;Pdx1-Cre (KC) mouse model Agr2 induction preceded the formation of pre-neoplastic lesions and their development was largely inhibited by Agr2 deletion in engineered LSL-KrasG12D;Pdx1-Cre; Agr2-/-mice. In vitro, AGR2 expression was stimulated by tunicamycin-induced endoplasmic reticulum (ER) stress in both KRAS wild-type normal pancreas cells, as well as in KRAS mutated pancreatic cancer cells and was essential for ER homoeostasis. The unfolded protein response proteins GRP78, ATF6 and XBP1s were found expressed in CP and PDAC peritumoral tissues, but in contrast to AGR2, their expression was switched off during TC and PanIN formation. Real-time PCR and ELISA analyses showed that ER stress induced a pro-inflammatory phenotype in pancreatic normal, cancer and stellate cells. Moreover, AGR2 expression was inducible by paracrine transfer of ER stress and pro-inflammation between different pancreatic cell types. Our findings demonstrate that AGR2 induced in ER-stressed and inflammatory pre-neoplastic pancreas is a potential marker of cancer progenitor cells with an important functional role in PDAC initiation.
authors.affiliation: Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK.
authors.forename: L
authors.initials: L
authors.lastname: Dumartin
authors.affiliation: Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK.
authors.forename: W
authors.initials: W
authors.lastname: Alrawashdeh
authors.affiliation: Centre for Stem Cells in Cancer &Ageing, Barts Cancer Institute, Queen Mary University of London, London, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Trabulo
authors.affiliation: Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK.
authors.forename: T P
authors.initials: TP
authors.lastname: Radon
authors.affiliation: Institute of Pathology, Technische Universität München, Munich, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Steiger
authors.affiliation: Department of Histopathology, Royal London Hospital, London, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Feakins
authors.affiliation: Department of Surgery, Cell and Developmental Biology, University of Michigan, Ann Arbor, USA.
authors.forename: M P
authors.initials: MP
authors.lastname: di Magliano
authors.affiliation: Centre for Stem Cells in Cancer &Ageing, Barts Cancer Institute, Queen Mary University of London, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Heeschen
authors.affiliation: Institute of Pathology, Heinrich-Heine-University of Düsseldorf, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Esposito
authors.affiliation: Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK.
authors.forename: N R
authors.initials: NR
authors.lastname: Lemoine
authors.affiliation: Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK.
authors.forename: T
authors.initials: T
authors.lastname: Crnogorac-Jurcevic
mesh_terms: D000818:Animals; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000502:physiology*; D006801:Humans; D051379:Mice; D009088:Mucoproteins / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D015513:Oncogene Proteins; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics / Q000378:metabolism
chemical_list: C526445:Agr2 protein, mouse; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; C000717248:Hspa5 protein, mouse; D009088:Mucoproteins; D015513:Oncogene Proteins; C495971:Hras protein, mouse; D016283:Proto-Oncogene Proteins p21(ras)