Publications by authors named "Ilse Rooman"

44 Publications

Cystine-glutamate antiporter deletion accelerates motor recovery and improves histological outcomes following spinal cord injury in mice.

Sci Rep 2021 Jun 9;11(1):12227. Epub 2021 Jun 9.

URPhyM - NARILIS, Université de Namur, Rue de Bruxelles 61, 5000, Namur, Belgium.

xCT is the specific subunit of System xc-, an antiporter importing cystine while releasing glutamate. Although xCT expression has been found in the spinal cord, its expression and role after spinal cord injury (SCI) remain unknown. The aim of this study was to characterize the role of xCT on functional and histological outcomes following SCI induced in wild-type (xCT+/+) and in xCT-deficient mice (xCT-/-). In the normal mouse spinal cord, slc7a11/xCT mRNA was detected in meningeal fibroblasts, vascular mural cells, astrocytes, motor neurons and to a lesser extent in microglia. slc7a11/xCT gene and protein were upregulated within two weeks post-SCI. xCT-/- mice recovered muscular grip strength as well as pre-SCI weight faster than xCT+/+ mice. Histology of xCT-/- spinal cords revealed significantly more spared motor neurons and a higher number of quiescent microglia. In xCT-/- mice, inflammatory polarization shifted towards higher mRNA expression of ym1 and igf1 (anti-inflammatory) while lower levels of nox2 and tnf-a (pro-inflammatory). Although astrocyte polarization did not differ, we quantified an increased expression of lcn2 mRNA. Our results show that slc7a11/xCT is overexpressed early following SCI and is detrimental to motor neuron survival. xCT deletion modulates intraspinal glial activation by shifting towards an anti-inflammatory profile.
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http://dx.doi.org/10.1038/s41598-021-91698-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8190126PMC
June 2021

Exploring new uses for existing drugs: innovative mechanisms to fund independent clinical research.

Trials 2021 May 4;22(1):322. Epub 2021 May 4.

Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.

Background: Finding new therapeutic uses for existing medicines could lead to safe, affordable and timely new treatment options for patients with high medical needs. However, due to a lack of economic incentives, pharmaceutical developers are rarely interested to invest in research with approved medicines, especially when they are out of basic patent or regulatory protection. Consequently, potential new uses for these medicines are mainly studied in independent clinical trials initiated and led by researchers from academia, research institutes, or collaborative groups. Yet, additional financial support is needed to conduct expensive phase III clinical trials to confirm the results from exploratory research.

Methods: In this study, scientific and grey literature was searched to identify and evaluate new mechanisms for funding clinical trials with repurposed medicines. Semi-structured interviews were conducted with 16 European stakeholders with expertise in clinical research, funding mechanisms and/or drug repurposing between November 2018 and February 2019 to consider the future perspectives of applying new funding mechanisms.

Results: Traditional grant funding awarded by government and philanthropic organisations or companies is well known and widely implemented in all research fields. In contrast, only little research has focused on the application potential of newer mechanisms to fund independent clinical research, such as social impact bonds, crowdfunding or public-private partnerships. Interviewees stated that there is a substantial need for additional financial support in health research, especially in areas where there is limited commercial interest. However, the implementation of new funding mechanisms is facing several practical and financial challenges, such as a lack of expertise and guidelines, high transaction costs and difficulties to measure health outcomes. Furthermore, interviewees highlighted the need for increased collaboration and centralisation at a European and international level to make clinical research more efficient and reduce the need for additional funding.

Conclusions: New funding mechanisms to support clinical research may become more important in the future but the unresolved issues identified in the current study warrant further exploration.
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http://dx.doi.org/10.1186/s13063-021-05273-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8093905PMC
May 2021

MECOM permits pancreatic acinar cell dedifferentiation avoiding cell death under stress conditions.

Cell Death Differ 2021 Mar 24. Epub 2021 Mar 24.

Laboratory of Medical and Molecular Oncology, Oncology Research Center, Vrije Universiteit Brussel, Laarbeeklaan 103, Jette, 1090, België.

Maintenance of the pancreatic acinar cell phenotype suppresses tumor formation. Hence, repetitive acute or chronic pancreatitis, stress conditions in which the acinar cells dedifferentiate, predispose for cancer formation in the pancreas. Dedifferentiated acinar cells acquire a large panel of duct cell-specific markers. However, it remains unclear to what extent dedifferentiated acini differ from native duct cells and which genes are uniquely regulating acinar cell dedifferentiation. Moreover, most studies have been performed on mice since the availability of human cells is scarce. Here, we applied a non-genetic lineage tracing method of human pancreatic exocrine acinar and duct cells that allowed cell-type-specific gene expression profiling by RNA sequencing. Subsequent to this discovery analysis, one transcription factor that was unique for dedifferentiated acinar cells was functionally characterized. RNA sequencing analysis showed that human dedifferentiated acinar cells expressed genes in "Pathways of cancer" with a prominence of MECOM (EVI-1), a transcription factor that was not expressed by duct cells. During mouse embryonic development, pre-acinar cells also transiently expressed MECOM and in the adult mouse pancreas, MECOM was re-expressed when mice were subjected to acute and chronic pancreatitis, conditions in which acinar cells dedifferentiate. In human cells and in mice, MECOM expression correlated with and was directly regulated by SOX9. Mouse acinar cells that, by genetic manipulation, lose the ability to upregulate MECOM showed impaired cell adhesion, more prominent acinar cell death, and suppressed acinar cell dedifferentiation by limited ERK signaling. In conclusion, we transcriptionally profiled the two major human pancreatic exocrine cell types, acinar and duct cells, during experimental stress conditions. We provide insights that in dedifferentiated acinar cells, cancer pathways are upregulated in which MECOM is a critical regulator that suppresses acinar cell death by permitting cellular dedifferentiation.
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http://dx.doi.org/10.1038/s41418-021-00771-6DOI Listing
March 2021

Nicotinamide combined with gemcitabine is an immunomodulatory therapy that restrains pancreatic cancer in mice.

J Immunother Cancer 2020 11;8(2)

Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA

Background: Treatments for pancreatic ductal adenocarcinoma are poorly effective, at least partly due to the tumor's immune-suppressive stromal compartment. New evidence of positive effects on immune responses in the tumor microenvironment (TME), compelled us to test the combination of gemcitabine (GEM), a standard chemotherapeutic for pancreatic cancer, with nicotinamide (NAM), the amide form of niacin (vitamin B), in mice with pancreatic cancer.

Methods: Various mouse tumor models of pancreatic cancer, that is, orthotopic Panc-02 and KPC (Kras, p53, Pdx1-Cre) grafts, were treated alternately with NAM and GEM for 2 weeks, and the effects on efficacy, survival, stromal architecture and tumor-infiltrating immune cells was examined by immunohistochemistry (IHC), flow cytometry, Enzyme-linked immunospot (ELISPOT), T cell depletions in vivo, Nanostring analysis and RNAscope.

Results: A significant reduction in tumor weight and number of metastases was found, as well as a significant improved survival of the NAM+GEM group compared with all control groups. IHC and flow cytometry showed a significant decrease in tumor-associated macrophages and myeloid-derived suppressor cells in the tumors of NAM+GEM-treated mice. This correlated with a significant increase in the number of CD4 and CD8 T cells of NAM+GEM-treated tumors, and CD4 and CD8 T cell responses to tumor-associated antigen survivin, most likely through epitope spreading. In vivo depletions of T cells demonstrated the involvement of CD4 T cells in the eradication of the tumor by NAM+GEM treatment. In addition, remodeling of the tumor stroma was observed with decreased collagen I and lower expression of hyaluronic acid binding protein, reorganization of the immune cells into lymph node like structures and CD31 positive vessels. Expression profiling for a panel of immuno-oncology genes revealed significant changes in genes involved in migration and activation of T cells, attraction of dendritic cells and epitope spreading.

Conclusion: This study highlights the potential of NAM+GEM as immunotherapy for advanced pancreatic cancer.
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http://dx.doi.org/10.1136/jitc-2020-001250DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7646363PMC
November 2020

Aggressive PDACs Show Hypomethylation of Repetitive Elements and the Execution of an Intrinsic IFN Program Linked to a Ductal Cell of Origin.

Cancer Discov 2021 Mar 15;11(3):638-659. Epub 2020 Oct 15.

German Cancer Consortium (DKTK), Heidelberg, Germany.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive desmoplasia, which challenges the molecular analyses of bulk tumor samples. Here we FACS-purified epithelial cells from human PDAC and normal pancreas and derived their genome-wide transcriptome and DNA methylome landscapes. Clustering based on DNA methylation revealed two distinct PDAC groups displaying different methylation patterns at regions encoding repeat elements. Methylation tumors are characterized by higher expression of endogenous retroviral transcripts and double-stranded RNA sensors, which lead to a cell-intrinsic activation of an interferon signature (IFNsign). This results in a protumorigenic microenvironment and poor patient outcome. Methylation/IFNsign and Methylation/IFNsign PDAC cells preserve lineage traits, respective of normal ductal or acinar pancreatic cells. Moreover, ductal-derived / mouse PDACs show higher expression of IFNsign compared with acinar-derived counterparts. Collectively, our data point to two different origins and etiologies of human PDACs, with the aggressive Methylation/IFNsign subtype potentially targetable by agents blocking intrinsic IFN signaling. SIGNIFICANCE: The mutational landscapes of PDAC alone cannot explain the observed interpatient heterogeneity. We identified two PDAC subtypes characterized by differential DNA methylation, preserving traits from normal ductal/acinar cells associated with IFN signaling. Our work suggests that epigenetic traits and the cell of origin contribute to PDAC heterogeneity..
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http://dx.doi.org/10.1158/2159-8290.CD-20-1202DOI Listing
March 2021

Pancreatic resection with perioperative drug repurposing of propranolol and etodolac: trial protocol of the phase-II randomised placebo controlled PROSPER trial.

BMJ Open 2020 09 30;10(9):e040406. Epub 2020 Sep 30.

Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany.

Introduction: Pancreatic cancer is the fourth-leading cause of cancer-related death in developed countries. Despite advances in systemic chemotherapy, the mainstay of curative therapy for non-metastatic disease is surgical resection. However, the perioperative period is characterised by stress and inflammatory reactions that can contribute to metastatic spread and disease recurrence. Catecholamines and prostaglandins play a crucial role in these reactions. Therefore, a drug repurposing of betablockers and cyclooxygenase inhibitors seems reasonable to attenuate tumour-associated inflammation by inhibiting psychological, surgical and inflammatory stress responses. This may cause a relevant antitumourigenic and antimetastatic effect during the perioperative period, a window for cancer-directed therapy that is currently largely unexploited.

Methods And Analysis: This is a prospective, single-centre, two-arm randomised, patient and observer blinded, placebo-controlled, phase-II trial evaluating safety and feasibility of combined perioperative treatment with propranolol and etodolac in adult patients with non-metastatic cancer of the pancreatic head undergoing elective pancreatoduodenectomy. 100 patients fulfilling the eligibility criteria will be randomised to perioperative treatment for 25 days perioperatively with a combination of propranolol and etodolac or placebo. Primary outcome of interest will be safety in terms of serious adverse events and reactions within 3 months. Furthermore, adherence to trial medication will be assessed as feasibility outcomes. Preliminary efficacy data will be evaluated for the purpose of power calculation for a potential subsequent phase-III trial. The clinical trial is accompanied by a translational study investigating the mechanisms of action of the combined therapy on a molecular basis.

Ethics And Dissemination: The PROSPER-trial has been approved by the German Federal Institute for Drugs and Medical Devices (reference number 4042875) and the Ethics Committee of the Medical Faculty of the University of Heidelberg (reference number AFmo-385/2018). The final trial results will be published in a peer-reviewed journal and will be presented at appropriate national and international conferences.

Trial Registration Numbers: DRKS00014054; EudraCT number: 2018-000415-25.
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http://dx.doi.org/10.1136/bmjopen-2020-040406DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7528424PMC
September 2020

On-Label or Off-Label? Overcoming Regulatory and Financial Barriers to Bring Repurposed Medicines to Cancer Patients.

Front Pharmacol 2019 31;10:1664. Epub 2020 Jan 31.

Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.

Repurposing of medicines has gained a lot of interest from the research community in recent years as it could offer safe, timely, and affordable new treatment options for cancer patients with high unmet needs. Increasingly, questions arise on how new uses will be translated into clinical practice, especially in case of marketed medicinal products that are out of basic patent or regulatory protection. The aim of this study was to portray the regulatory framework relevant for making repurposed medicines available to cancer patients in Europe and propose specific policy recommendations to address the current regulatory and financial barriers. We outlined two routes relevant to the clinical adoption of a repurposed medicine. First, a new indication can be approved, and thus brought on-label, the marketing authorization procedures established in European and national legislation. Such procedures initiate a detailed and independent assessment of the quality and the benefit-risk balance of a medicinal product in a specific indication, benefiting both prescribers and patients as it reassures them that the scientific evidence is robust. However, the process of marketing authorization for new therapeutic indications entails a high administrative burden and significant costs while the return-on-investment for the pharmaceutical industry is expected to be low or absent for medicines that are out of basic patent and regulatory protection. Moreover, most of the repurposing research is conducted by independent or academic researchers who do not have the expertise or resources to get involved in regulatory procedures. A second option is to prescribe a medicine off-label for the new indication, which is managed at the national level in Europe. While off-label use could provide timely access to treatments for patients with urgent medical needs, it also entails important safety, liability and financial risks for patients, physicians, and society at large. In view of that, we recommend finding solutions to facilitate bringing new uses on-label, for example by developing a collaborative framework between not-for-profit and academic organizations, pharmaceutical industry, health technology assessment bodies, payers, and regulators.
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http://dx.doi.org/10.3389/fphar.2019.01664DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7006723PMC
January 2020

Adult human pancreatic acinar cells dedifferentiate into an embryonic progenitor-like state in 3D suspension culture.

Sci Rep 2019 03 11;9(1):4040. Epub 2019 Mar 11.

Cell Differentiation Laboratory, Vrije Universiteit Brussel, 1090, Brussels, Belgium.

Human pancreatic exocrine cells were cultured in 3D suspension and formed pancreatospheres composed of acinar-derived and duct-like cells. We investigated, up to 6 days, the fate of human pancreatic acinar cells using fluorescein-conjugated Ulex Europaeus Agglutinin 1 lectin, a previously published acinar-specific non-genetic lineage tracing strategy. At day 4, fluorescence-activated cell sort for the intracellularly incorporated FITC-conjugated UEA1 lectin and the duct-specific CA19.9 surface marker, distinguished acinar-derived cells (UEA1CA19.9) from duct-like cells (UEA1CA19.9) and acinar-to-duct-like transdifferentiated cells (UEA1CA19.9). mRNA expression analysis of the acinar-derived (UEA1CA19.9) and duct-like (UEA1CA19.9) cell fractions with concomitant immunocytochemical analysis of the pancreatospheres revealed acquisition of an embryonic signature in the UEA1CA19.9 acinar-derived cells characterized by de novo expression of SOX9 and CD142, robust expression of PDX1 and surface expression of GP2. The colocalisation of CD142, a multipotent pancreatic progenitor surface marker, PDX1, SOX9 and GP2 is reminiscent of a cellular state present during human embryonic development. Addition of TGF-beta signalling inhibitor Alk5iII, induced a 28-fold increased KI67-labeling in pancreatospheres, more pronounced in the CD142GP2 acinar-derived cells. These findings with human cells underscore the remarkable plasticity of pancreatic exocrine acinar cells, previously described in rodents, and could find applications in the field of regenerative medicine.
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http://dx.doi.org/10.1038/s41598-019-40481-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6411888PMC
March 2019

ReDO_DB: the repurposing drugs in oncology database.

Ecancermedicalscience 2018 6;12:886. Epub 2018 Dec 6.

The Anticancer Fund, Brussels, 1853 Strombeek-Bever, Belgium.

Repurposing is a drug development strategy that seeks to use existing medications for new indications. In oncology, there is an increased level of activity looking at the use of non-cancer drugs as possible cancer treatments. The Repurposing Drugs in Oncology (ReDO) project has used a literature-based approach to identify licensed non-cancer drugs with published evidence of anticancer activity. Data from 268 drugs have been included in a database (ReDO_DB) developed by the ReDO project. Summary results are outlined and an assessment of clinical trial activity also described. The database has been made available as an online open-access resource (http://www.redo-project.org/db/).
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http://dx.doi.org/10.3332/ecancer.2018.886DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6345075PMC
December 2018

ROBO2 is a stroma suppressor gene in the pancreas and acts via TGF-β signalling.

Nat Commun 2018 11 30;9(1):5083. Epub 2018 Nov 30.

Australian Pancreatic Cancer Genome Initiative (APGI), Sydney, Darlinghurst 2010, NSW, Australia.

Whereas genomic aberrations in the SLIT-ROBO pathway are frequent in pancreatic ductal adenocarcinoma (PDAC), their function in the pancreas is unclear. Here we report that in pancreatitis and PDAC mouse models, epithelial Robo2 expression is lost while Robo1 expression becomes most prominent in the stroma. Cell cultures of mice with loss of epithelial Robo2 (Pdx1;Robo2) show increased activation of Robo1 myofibroblasts and induction of TGF-β and Wnt pathways. During pancreatitis, Pdx1;Robo2 mice present enhanced myofibroblast activation, collagen crosslinking, T-cell infiltration and tumorigenic immune markers. The TGF-β inhibitor galunisertib suppresses these effects. In PDAC patients, ROBO2 expression is overall low while ROBO1 is variably expressed in epithelium and high in stroma. ROBO2;ROBO1 patients present the poorest survival. In conclusion, Robo2 acts non-autonomously as a stroma suppressor gene by restraining myofibroblast activation and T-cell infiltration. ROBO1/2 expression in PDAC patients may guide therapy with TGF-β inhibitors or other stroma /immune modulating agents.
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http://dx.doi.org/10.1038/s41467-018-07497-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6269509PMC
November 2018

Young GI angle: My biggest (career) mistake.

United European Gastroenterol J 2018 Oct 30;6(8):1278-1279. Epub 2018 Sep 30.

Oncology Research Centre, Vrije Universiteit Brussel, Brussels, Belgium.

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http://dx.doi.org/10.1177/2050640618803045DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6169041PMC
October 2018

Whole-genome landscape of pancreatic neuroendocrine tumours.

Nature 2017 03 15;543(7643):65-71. Epub 2017 Feb 15.

QIMR Berghofer Medical Research Institute, Herston Road, Brisbane 4006, Australia.

The diagnosis of pancreatic neuroendocrine tumours (PanNETs) is increasing owing to more sensitive detection methods, and this increase is creating challenges for clinical management. We performed whole-genome sequencing of 102 primary PanNETs and defined the genomic events that characterize their pathogenesis. Here we describe the mutational signatures they harbour, including a deficiency in G:C > T:A base excision repair due to inactivation of MUTYH, which encodes a DNA glycosylase. Clinically sporadic PanNETs contain a larger-than-expected proportion of germline mutations, including previously unreported mutations in the DNA repair genes MUTYH, CHEK2 and BRCA2. Together with mutations in MEN1 and VHL, these mutations occur in 17% of patients. Somatic mutations, including point mutations and gene fusions, were commonly found in genes involved in four main pathways: chromatin remodelling, DNA damage repair, activation of mTOR signalling (including previously undescribed EWSR1 gene fusions), and telomere maintenance. In addition, our gene expression analyses identified a subgroup of tumours associated with hypoxia and HIF signalling.
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http://dx.doi.org/10.1038/nature21063DOI Listing
March 2017

ROCK signaling promotes collagen remodeling to facilitate invasive pancreatic ductal adenocarcinoma tumor cell growth.

EMBO Mol Med 2017 02;9(2):198-218

Cancer Research UK Beatson Institute, Glasgow, UK

Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer death; identifying PDAC enablers may reveal potential therapeutic targets. Expression of the actomyosin regulatory ROCK1 and ROCK2 kinases increased with tumor progression in human and mouse pancreatic tumors, while elevated ROCK1/ROCK2 expression in human patients, or conditional ROCK2 activation in a Kras/p53 mouse PDAC model, was associated with reduced survival. Conditional ROCK1 or ROCK2 activation promoted invasive growth of mouse PDAC cells into three-dimensional collagen matrices by increasing matrix remodeling activities. RNA sequencing revealed a coordinated program of ROCK-induced genes that facilitate extracellular matrix remodeling, with greatest fold-changes for matrix metalloproteinases (MMPs) Mmp10 and Mmp13 MMP inhibition not only decreased collagen degradation and invasion, but also reduced proliferation in three-dimensional contexts. Treatment of Kras/p53 PDAC mice with a ROCK inhibitor prolonged survival, which was associated with increased tumor-associated collagen. These findings reveal an ancillary role for increased ROCK signaling in pancreatic cancer progression to promote extracellular matrix remodeling that facilitates proliferation and invasive tumor growth.
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http://dx.doi.org/10.15252/emmm.201606743DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5286371PMC
February 2017

Repurposing Drugs in Oncology (ReDO)-Propranolol as an anti-cancer agent.

Ecancermedicalscience 2016 12;10:680. Epub 2016 Oct 12.

GlobalCures, Inc, Newton MA 02459, USA; Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.

Propranolol (PRO) is a well-known and widely used non-selective beta-adrenergic receptor antagonist (beta-blocker), with a range of actions which are of interest in an oncological context. PRO displays effects on cellular proliferation and invasion, on the immune system, on the angiogenic cascade, and on tumour cell sensitivity to existing treatments. Both pre-clinical and clinical evidence of these effects, in multiple cancer types, is assessed and summarised and relevant mechanisms of action outlined. In particular there is evidence that PRO is effective at multiple points in the metastatic cascade, particularly in the context of the post-surgical wound response. Based on this evidence the case is made for further clinical investigation of the anticancer effects of PRO, particularly in combination with other agents. A number of trials are on-going, in different treatment settings for various cancers.
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http://dx.doi.org/10.3332/ecancer.2016.680DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5102691PMC
October 2016

Hypermutation In Pancreatic Cancer.

Gastroenterology 2017 01 15;152(1):68-74.e2. Epub 2016 Nov 15.

QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia.

Pancreatic cancer is molecularly diverse, with few effective therapies. Increased mutation burden and defective DNA repair are associated with response to immune checkpoint inhibitors in several other cancer types. We interrogated 385 pancreatic cancer genomes to define hypermutation and its causes. Mutational signatures inferring defects in DNA repair were enriched in those with the highest mutation burdens. Mismatch repair deficiency was identified in 1% of tumors harboring different mechanisms of somatic inactivation of MLH1 and MSH2. Defining mutation load in individual pancreatic cancers and the optimal assay for patient selection may inform clinical trial design for immunotherapy in pancreatic cancer.
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http://dx.doi.org/10.1053/j.gastro.2016.09.060DOI Listing
January 2017

Sirtuin 1 stimulates the proliferation and the expression of glycolysis genes in pancreatic neoplastic lesions.

Oncotarget 2016 11;7(46):74768-74778

Cancer Division, The Garvan Institute of Medical Research, Sydney, Australia.

Metabolic reprogramming is a feature of neoplasia and tumor growth. Sirtuin 1 (SIRT1) is a lysine deacetylase of multiple targets including metabolic regulators such as p53. SIRT1 regulates metaplasia in the pancreas. Nevertheless, it is unclear if SIRT1 affects the development of neoplastic lesions and whether metabolic gene expression is altered.To assess neoplastic lesion development, mice with a pancreas-specific loss of Sirt1 (Pdx1-Cre;Sirt1-lox) were bred into a KrasG12D mutant background (KC) that predisposes to the development of pancreatic intra-epithelial neoplasia (PanIN) and ductal adenocarcinoma (PDAC). Similar grade PanIN lesions developed in KC and KC;Sirt1-lox mice but specifically early mucinous PanINs occupied 40% less area in the KC;Sirt1-lox line, attributed to reduced proliferation. This was accompanied by reduced expression of proteins in the glycolysis pathway, such as GLUT1 and GAPDH.The stimulatory effect of SIRT1 on proliferation and glycolysis gene expression was confirmed in a human PDAC cell line. In resected PDAC samples, higher proliferation and expression of glycolysis genes correlated with poor patient survival. SIRT1 expression per se was not prognostic but low expression of Cell Cycle and Apoptosis Regulator 2 (CCAR2), a reported SIRT1 inhibitor, corresponded to poor patient survival.These findings open perspectives for novel targeted therapies in pancreatic cancer.
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http://dx.doi.org/10.18632/oncotarget.11013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5342700PMC
November 2016

Genomic analyses identify molecular subtypes of pancreatic cancer.

Nature 2016 Mar 24;531(7592):47-52. Epub 2016 Feb 24.

Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.

Integrated genomic analysis of 456 pancreatic ductal adenocarcinomas identified 32 recurrently mutated genes that aggregate into 10 pathways: KRAS, TGF-β, WNT, NOTCH, ROBO/SLIT signalling, G1/S transition, SWI-SNF, chromatin modification, DNA repair and RNA processing. Expression analysis defined 4 subtypes: (1) squamous; (2) pancreatic progenitor; (3) immunogenic; and (4) aberrantly differentiated endocrine exocrine (ADEX) that correlate with histopathological characteristics. Squamous tumours are enriched for TP53 and KDM6A mutations, upregulation of the TP63∆N transcriptional network, hypermethylation of pancreatic endodermal cell-fate determining genes and have a poor prognosis. Pancreatic progenitor tumours preferentially express genes involved in early pancreatic development (FOXA2/3, PDX1 and MNX1). ADEX tumours displayed upregulation of genes that regulate networks involved in KRAS activation, exocrine (NR5A2 and RBPJL), and endocrine differentiation (NEUROD1 and NKX2-2). Immunogenic tumours contained upregulated immune networks including pathways involved in acquired immune suppression. These data infer differences in the molecular evolution of pancreatic cancer subtypes and identify opportunities for therapeutic development.
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http://dx.doi.org/10.1038/nature16965DOI Listing
March 2016

Emerging Drug Target In Pancreatic Cancer: Placing Sirtuin 1 on the Canvas.

Curr Cancer Drug Targets 2015 ;15(6):463-8

The Garvan Institute of Medical Research, Sydney, Australia.

Sirtuin 1 is a protein deacetylase that regulates a large number of proteins often functionally implicated in tumor development and progression. Its pleiotropic function has turned SIRT1 into an attractive chemotherapeutic target, underscored by very promising preclinical results with SIRT1 inhibitors in the treatment of chronic myeloid leukemia. Here, we revisit the studies on SIRT1 as an emerging target for therapy in pancreatic cancer, a tumor with dismal outcomes for which currently few therapeutic options are available. We highlight those potential SIRT1 target genes that are commonly affected in pancreatic cancer according to recent genomic analyses.
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http://dx.doi.org/10.2174/1568009615666150512102957DOI Listing
May 2016

Pancreas-Specific Sirt1-Deficiency in Mice Compromises Beta-Cell Function without Development of Hyperglycemia.

PLoS One 2015 5;10(6):e0128012. Epub 2015 Jun 5.

Cancer Division, Garvan Institute of Medical Research, The Kinghorn Cancer Centre, Darlinghurst NSW, Australia; St. Vincent's Clinical School, Faculty of Medicine, UNSW Australia, Randwick NSW, Australia; Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium.

Aims/hypothesis: Sirtuin 1 (Sirt1) has been reported to be a critical positive regulator of glucose-stimulated insulin secretion in pancreatic beta-cells. The effects on islet cells and blood glucose levels when Sirt1 is deleted specifically in the pancreas are still unclear.

Methods: This study examined islet glucose responsiveness, blood glucose levels, pancreatic islet histology and gene expression in Pdx1Cre; Sirt1ex4F/F mice that have loss of function and loss of expression of Sirt1 specifically in the pancreas.

Results: We found that in the Pdx1Cre; Sirt1ex4F/F mice, the relative insulin positive area and the islet size distribution were unchanged. However, beta-cells were functionally impaired, presenting with lower glucose-stimulated insulin secretion. This defect was not due to a reduced expression of insulin but was associated with a decreased expression of the glucose transporter Slc2a2/Glut2 and of the Glucagon like peptide-1 receptor (Glp1r) as well as a marked down regulation of endoplasmic reticulum (ER) chaperones that participate in the Unfolded Protein Response (UPR) pathway. Counter intuitively, the Sirt1-deficient mice did not develop hyperglycemia. Pancreatic polypeptide (PP) cells were the only other islet cells affected, with reduced numbers in the Sirt1-deficient pancreas.

Conclusions/interpretation: This study provides new mechanistic insights showing that beta-cell function in Sirt1-deficient pancreas is affected due to altered glucose sensing and deregulation of the UPR pathway. Interestingly, we uncovered a context in which impaired beta-cell function is not accompanied by increased glycemia. This points to a unique compensatory mechanism. Given the reduction in PP, investigation of its role in the control of blood glucose is warranted.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0128012PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4457418PMC
March 2016

Whole genomes redefine the mutational landscape of pancreatic cancer.

Nature 2015 Feb;518(7540):495-501

Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.

Pancreatic cancer remains one of the most lethal of malignancies and a major health burden. We performed whole-genome sequencing and copy number variation (CNV) analysis of 100 pancreatic ductal adenocarcinomas (PDACs). Chromosomal rearrangements leading to gene disruption were prevalent, affecting genes known to be important in pancreatic cancer (TP53, SMAD4, CDKN2A, ARID1A and ROBO2) and new candidate drivers of pancreatic carcinogenesis (KDM6A and PREX2). Patterns of structural variation (variation in chromosomal structure) classified PDACs into 4 subtypes with potential clinical utility: the subtypes were termed stable, locally rearranged, scattered and unstable. A significant proportion harboured focal amplifications, many of which contained druggable oncogenes (ERBB2, MET, FGFR1, CDK6, PIK3R3 and PIK3CA), but at low individual patient prevalence. Genomic instability co-segregated with inactivation of DNA maintenance genes (BRCA1, BRCA2 or PALB2) and a mutational signature of DNA damage repair deficiency. Of 8 patients who received platinum therapy, 4 of 5 individuals with these measures of defective DNA maintenance responded.
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http://dx.doi.org/10.1038/nature14169DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4523082PMC
February 2015

Sirtainties in pancreatic cancer?

Authors:
Ilse Rooman

Oncoscience 2014 3;1(3):183-4. Epub 2014 Apr 3.

The Garvan Institute of Medical Research / The Kinghorn Cancer Centre, Darlinghurst, Australia.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4278293PMC
http://dx.doi.org/10.18632/oncoscience.28DOI Listing
January 2015

SOX9 regulates ERBB signalling in pancreatic cancer development.

Gut 2015 Nov 21;64(11):1790-9. Epub 2014 Oct 21.

Université catholique de Louvain, de Duve Institute, Brussels, Belgium.

Objective: The transcription factor SOX9 was recently shown to stimulate ductal gene expression in pancreatic acinar-to-ductal metaplasia and to accelerate development of premalignant lesions preceding pancreatic ductal adenocarcinoma (PDAC). Here, we investigate how SOX9 operates in pancreatic tumourigenesis.

Design: We analysed genomic and transcriptomic data from surgically resected PDAC and extended the expression analysis to xenografts from PDAC samples and to PDAC cell lines. SOX9 expression was manipulated in human cell lines and mouse models developing PDAC.

Results: We found genetic aberrations in the SOX9 gene in about 15% of patient tumours. Most PDAC samples strongly express SOX9 protein, and SOX9 levels are higher in classical PDAC. This tumour subtype is associated with better patient outcome, and cell lines of this subtype respond to therapy targeting epidermal growth factor receptor (EGFR/ERBB1) signalling, a pathway essential for pancreatic tumourigenesis. In human PDAC, high expression of SOX9 correlates with expression of genes belonging to the ERBB pathway. In particular, ERBB2 expression in PDAC cell lines is stimulated by SOX9. Inactivating Sox9 expression in mice confirmed its role in PDAC initiation; it demonstrated that Sox9 stimulates expression of several members of the ERBB pathway and is required for ERBB signalling activity.

Conclusions: By integrating data from patient samples and mouse models, we found that SOX9 regulates the ERBB pathway throughout pancreatic tumourigenesis. Our work opens perspectives for therapy targeting tumourigenic mechanisms.
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http://dx.doi.org/10.1136/gutjnl-2014-307075DOI Listing
November 2015

Genome-wide DNA methylation patterns in pancreatic ductal adenocarcinoma reveal epigenetic deregulation of SLIT-ROBO, ITGA2 and MET signaling.

Int J Cancer 2014 Sep 9;135(5):1110-8. Epub 2014 May 9.

Queensland Centre for Medical Genomics, Institute for Molecular Bioscience, The University of Queensland, St Lucia, Brisbane, QLD, Australia.

The importance of epigenetic modifications such as DNA methylation in tumorigenesis is increasingly being appreciated. To define the genome-wide pattern of DNA methylation in pancreatic ductal adenocarcinomas (PDAC), we captured the methylation profiles of 167 untreated resected PDACs and compared them to a panel of 29 adjacent nontransformed pancreata using high-density arrays. A total of 11,634 CpG sites associated with 3,522 genes were significantly differentially methylated (DM) in PDAC and were capable of segregating PDAC from non-malignant pancreas, regardless of tumor cellularity. As expected, PDAC hypermethylation was most prevalent in the 5' region of genes (including the proximal promoter, 5'UTR and CpG islands). Approximately 33% DM genes showed significant inverse correlation with mRNA expression levels. Pathway analysis revealed an enrichment of aberrantly methylated genes involved in key molecular mechanisms important to PDAC: TGF-β, WNT, integrin signaling, cell adhesion, stellate cell activation and axon guidance. Given the recent discovery that SLIT-ROBO mutations play a clinically important role in PDAC, the role of epigenetic perturbation of axon guidance was pursued in more detail. Bisulfite amplicon deep sequencing and qRT-PCR expression analyses confirmed recurrent perturbation of axon guidance pathway genes SLIT2, SLIT3, ROBO1, ROBO3, ITGA2 and MET and suggests epigenetic suppression of SLIT-ROBO signaling and up-regulation of MET and ITGA2 expression. Hypomethylation of MET and ITGA2 correlated with high gene expression, which was associated with poor survival. These data suggest that aberrant methylation plays an important role in pancreatic carcinogenesis affecting core signaling pathways with potential implications for the disease pathophysiology and therapy.
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http://dx.doi.org/10.1002/ijc.28765DOI Listing
September 2014

Amino acid transporters expression in acinar cells is changed during acute pancreatitis.

Pancreatology 2013 Sep-Oct;13(5):475-85. Epub 2013 Jun 27.

Cancer Research Program, The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Darlinghurst-Sydney, NSW, Australia; St Vincent's Clinical School, University New South Wales, Australia; Cell Differentiation Unit, Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium.

Pancreatic acinar cells accumulate amino acids against a marked concentration gradient to synthesize digestive enzymes. Thus, the function of acinar cells depends on amino acid uptake mediated by active transport. Despite the importance of this process, pancreatic amino acid transporter expression and cellular localization is still unclear. We screened mouse pancreas for the expression of genes encoding amino acid transporters. We showed that the most highly expressed transporters, namely sodium dependent SNAT3 (Slc38a3) and SNAT5 (Slc38a5) and sodium independent neutral amino acids transporters LAT1 (Slc7a5) and LAT2 (Slc7a8), are expressed in the basolateral membrane of acinar cells. SNAT3 and SNAT5, LAT1 and LAT2 are expressed in acinar cells. Additional evidence that these transporters are expressed in mature acinar cells was gained using acinar cell culture and acute pancreatitis models. In the acute phase of pancreatic injury, when acinar cell loss occurs, and in an acinar cell culture model, which mimics changes occurring during pancreatitis, SNAT3 and SNAT5 are strongly down-regulated. LAT1 and LAT2 were down-regulated only in the in vitro model. At protein level, SNAT3 and SNAT5 expression was also reduced during pancreatitis. Expression of other amino acid transporters was also modified in both models of pancreatitis. The subset of transporters with differential expression patterns during acute pancreatitis might be involved in the injury/regeneration phases. Further expression, localization and functional studies will follow to better understand changes occurring during acute pancreatitis. These findings provide insight into pancreatic amino acid transport in healthy pancreas and during acute pancreatitis injury.
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http://dx.doi.org/10.1016/j.pan.2013.06.006DOI Listing
May 2014

Clinical and molecular characterization of HER2 amplified-pancreatic cancer.

Genome Med 2013 31;5(8):78. Epub 2013 Aug 31.

Kinghorn Cancer Centre and Garvan Institute of Medical Research, Darlinghurst, Sydney, Australia ; Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, UK ; West of Scotland Pancreatic Unit, Glasgow Royal Infirmary, Glasgow, UK.

Background: Pancreatic cancer is one of the most lethal and molecularly diverse malignancies. Repurposing of therapeutics that target specific molecular mechanisms in different disease types offers potential for rapid improvements in outcome. Although HER2 amplification occurs in pancreatic cancer, it is inadequately characterized to exploit the potential of anti-HER2 therapies.

Methods: HER2 amplification was detected and further analyzed using multiple genomic sequencing approaches. Standardized reference laboratory assays defined HER2 amplification in a large cohort of patients (n = 469) with pancreatic ductal adenocarcinoma (PDAC).

Results: An amplified inversion event (1 MB) was identified at the HER2 locus in a patient with PDAC. Using standardized laboratory assays, we established diagnostic criteria for HER2 amplification in PDAC, and observed a prevalence of 2%. Clinically, HER2- amplified PDAC was characterized by a lack of liver metastases, and a preponderance of lung and brain metastases. Excluding breast and gastric cancer, the incidence of HER2-amplified cancers in the USA is >22,000 per annum.

Conclusions: HER2 amplification occurs in 2% of PDAC, and has distinct features with implications for clinical practice. The molecular heterogeneity of PDAC implies that even an incidence of 2% represents an attractive target for anti-HER2 therapies, as options for PDAC are limited. Recruiting patients based on HER2 amplification, rather than organ of origin, could make trials of anti-HER2 therapies feasible in less common cancer types.
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http://dx.doi.org/10.1186/gm482DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3978667PMC
May 2014

Chronic pancreatitis: a path to pancreatic cancer.

Cancer Lett 2014 Apr 24;345(2):203-9. Epub 2013 Aug 24.

Cancer Research Program, The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, Australia; St. Vincent's Clinical School, University of New South Wales, Sydney, Australia; Diabetes Research Center, Vrije Universiteit Brussel, Brussels, Belgium. Electronic address:

Chronic pancreatitis predisposes to pancreatic cancer development and both diseases share a common etiology. A central role has been proposed for the digestive enzyme-secreting acinar cell that can undergo ductal metaplasia in the inflammatory environment of pancreatitis. This metaplastic change is now a recognised precursor of pancreatic cancer. Inflammatory molecules also foster tumour growth through autocrine and paracrine effects in the epithelium and the stroma. These insights have raised new opportunities such as the manipulation of inflammation as a preventive and/or therapeutic strategy for pancreatic cancer. Finally, we address the need for an in-depth study of the pancreatic acinar cells.
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http://dx.doi.org/10.1016/j.canlet.2013.08.015DOI Listing
April 2014

Histomolecular phenotypes and outcome in adenocarcinoma of the ampulla of vater.

J Clin Oncol 2013 Apr 25;31(10):1348-56. Epub 2013 Feb 25.

Cancer Research Program, Garvan Institute of Medical Research, Sydney, NSW 2010 Australia.

Purpose: Individuals with adenocarcinoma of the ampulla of Vater demonstrate a broad range of outcomes, presumably because these cancers may arise from any one of the three epithelia that converge at that location. This variability poses challenges for clinical decision making and the development of novel therapeutic strategies.

Patients And Methods: We assessed the potential clinical utility of histomolecular phenotypes defined using a combination of histopathology and protein expression (CDX2 and MUC1) in 208 patients from three independent cohorts who underwent surgical resection for adenocarcinoma of the ampulla of Vater.

Results: Histologic subtype and CDX2 and MUC1 expression were significant prognostic variables. Patients with a histomolecular pancreaticobiliary phenotype (CDX2 negative, MUC1 positive) segregated into a poor prognostic group in the training (hazard ratio [HR], 3.34; 95% CI, 1.69 to 6.62; P < .001) and both validation cohorts (HR, 5.65; 95% CI, 2.77 to 11.5; P < .001 and HR, 2.78; 95% CI, 1.25 to 7.17; P = .0119) compared with histomolecular nonpancreaticobiliary carcinomas. Further stratification by lymph node (LN) status defined three clinically relevant subgroups: one, patients with histomolecular nonpancreaticobiliary (intestinal) carcinoma without LN metastases who had an excellent prognosis; two, those with histomolecular pancreaticobiliary carcinoma with LN metastases who had a poor outcome; and three, the remainder of patients (nonpancreaticobiliary, LN positive or pancreaticobiliary, LN negative) who had an intermediate outcome.

Conclusion: Histopathologic and molecular criteria combine to define clinically relevant histomolecular phenotypes of adenocarcinoma of the ampulla of Vater and potentially represent distinct diseases with significant implications for current therapeutic strategies, the ability to interpret past clinical trials, and future trial design.
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http://dx.doi.org/10.1200/JCO.2012.46.8868DOI Listing
April 2013

Sirtuin-1 regulates acinar-to-ductal metaplasia and supports cancer cell viability in pancreatic cancer.

Cancer Res 2013 Apr 31;73(7):2357-67. Epub 2013 Jan 31.

Cancer Research Program, Garvan Institute of Medical Research, Sydney, Australia.

The exocrine pancreas can undergo acinar-to-ductal metaplasia (ADM), as in the case of pancreatitis where precursor lesions of pancreatic ductal adenocarcinoma (PDAC) can arise. The NAD(+)-dependent protein deacetylase Sirtuin-1 (Sirt1) has been implicated in carcinogenesis with dual roles depending on its subcellular localization. In this study, we examined the expression and the role of Sirt1 in different stages of pancreatic carcinogenesis, i.e. ADM models and established PDAC. In addition, we analyzed the expression of KIAA1967, a key mediator of Sirt1 function, along with potential Sirt1 downstream targets. Sirt1 was co-expressed with KIAA1967 in the nuclei of normal pancreatic acinar cells. In ADM, Sirt1 underwent a transient nuclear-to-cytoplasmic shuttling. Experiments where during ADM, we enforced repression of Sirt1 shuttling, inhibition of Sirt1 activity or modulation of its expression, all underscore that the temporary decrease of nuclear and increase of cytoplasmic Sirt1 stimulate ADM. Our results further underscore that important transcriptional regulators of acinar differentiation, that is, Pancreatic transcription factor-1a and β-catenin can be deacetylated by Sirt1. Inhibition of Sirt1 is effective in suppression of ADM and in reducing cell viability in established PDAC tumors. KIAA1967 expression is differentially downregulated in PDAC and impacts on the sensitivity of PDAC cells to the Sirt1/2 inhibitor Tenovin-6. In PDAC, acetylation of β-catenin is not affected, unlike p53, a well-characterized Sirt1-regulated protein in tumor cells. Our results reveal that Sirt1 is an important regulator and potential therapeutic target in pancreatic carcinogenesis.
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http://dx.doi.org/10.1158/0008-5472.CAN-12-3359DOI Listing
April 2013

Pancreatic cancer genomes reveal aberrations in axon guidance pathway genes.

Nature 2012 Nov 24;491(7424):399-405. Epub 2012 Oct 24.

The Kinghorn Cancer Centre, 370 Victoria Street, Darlinghurst, Sydney, New South Wales 2010, Australia.

Pancreatic cancer is a highly lethal malignancy with few effective therapies. We performed exome sequencing and copy number analysis to define genomic aberrations in a prospectively accrued clinical cohort (n = 142) of early (stage I and II) sporadic pancreatic ductal adenocarcinoma. Detailed analysis of 99 informative tumours identified substantial heterogeneity with 2,016 non-silent mutations and 1,628 copy-number variations. We define 16 significantly mutated genes, reaffirming known mutations (KRAS, TP53, CDKN2A, SMAD4, MLL3, TGFBR2, ARID1A and SF3B1), and uncover novel mutated genes including additional genes involved in chromatin modification (EPC1 and ARID2), DNA damage repair (ATM) and other mechanisms (ZIM2, MAP2K4, NALCN, SLC16A4 and MAGEA6). Integrative analysis with in vitro functional data and animal models provided supportive evidence for potential roles for these genetic aberrations in carcinogenesis. Pathway-based analysis of recurrently mutated genes recapitulated clustering in core signalling pathways in pancreatic ductal adenocarcinoma, and identified new mutated genes in each pathway. We also identified frequent and diverse somatic aberrations in genes described traditionally as embryonic regulators of axon guidance, particularly SLIT/ROBO signalling, which was also evident in murine Sleeping Beauty transposon-mediated somatic mutagenesis models of pancreatic cancer, providing further supportive evidence for the potential involvement of axon guidance genes in pancreatic carcinogenesis.
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http://dx.doi.org/10.1038/nature11547DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3530898PMC
November 2012
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