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Pancreatic Neoplasms: HELP
Articles by Mathieu Lemire
Based on 5 articles published since 2009
(Why 5 articles?)
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Between 2009 and 2019, Mathieu Lemire wrote the following 5 articles about Pancreatic Neoplasms.
 
+ Citations + Abstracts
1 Article Whole genomes define concordance of matched primary, xenograft, and organoid models of pancreas cancer. 2019

Gendoo, Deena M A / Denroche, Robert E / Zhang, Amy / Radulovich, Nikolina / Jang, Gun Ho / Lemire, Mathieu / Fischer, Sandra / Chadwick, Dianne / Lungu, Ilinca M / Ibrahimov, Emin / Cao, Ping-Jiang / Stein, Lincoln D / Wilson, Julie M / Bartlett, John M S / Tsao, Ming-Sound / Dhani, Neesha / Hedley, David / Gallinger, Steven / Haibe-Kains, Benjamin. ·Centre for Computational Biology, Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom. · School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom. · PanCuRx Translational Research Initiative, Ontario Institute of Cancer Research (OICR), Toronto, Ontario, Canada. · Informatics and Bio-computing Program, Ontario Institute for Cancer Research, Toronto, Ontario, Canada. · Princess Margaret Living Biobank Core, University Health Network, Toronto, Ontario, Canada. · Department of Statistical Science, University of Toronto, Toronto, Ontario, Canada. · Department of Pathology, University Health Network, University of Toronto, Toronto, Ontario, Canada. · UHN Program in BioSpecimen Sciences, Department of Pathology, University Health Network, Toronto, Ontario, Canada. · Transformative Pathology, Ontario Institute for Cancer Research, Toronto, Ontario, Canada. · Division of Medical Oncology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada. · Molecular Genetics Department, University of Toronto, Toronto, Ontario, Canada. · Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada. · Hepatobiliary/Pancreatic Surgical Oncology Program, University Health Network, Toronto, Ontario, Canada. · Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada. · Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada. · Vector Institute, Toronto, Ontario, Canada. ·PLoS Comput Biol · Pubmed #30629588.

ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis among solid malignancies and improved therapeutic strategies are needed to improve outcomes. Patient-derived xenografts (PDX) and patient-derived organoids (PDO) serve as promising tools to identify new drugs with therapeutic potential in PDAC. For these preclinical disease models to be effective, they should both recapitulate the molecular heterogeneity of PDAC and validate patient-specific therapeutic sensitivities. To date however, deep characterization of the molecular heterogeneity of PDAC PDX and PDO models and comparison with matched human tumour remains largely unaddressed at the whole genome level. We conducted a comprehensive assessment of the genetic landscape of 16 whole-genome pairs of tumours and matched PDX, from primary PDAC and liver metastasis, including a unique cohort of 5 'trios' of matched primary tumour, PDX, and PDO. We developed a pipeline to score concordance between PDAC models and their paired human tumours for genomic events, including mutations, structural variations, and copy number variations. Tumour-model comparisons of mutations displayed single-gene concordance across major PDAC driver genes, but relatively poor agreement across the greater mutational load. Genome-wide and chromosome-centric analysis of structural variation (SV) events highlights previously unrecognized concordance across chromosomes that demonstrate clustered SV events. We found that polyploidy presented a major challenge when assessing copy number changes; however, ploidy-corrected copy number states suggest good agreement between donor-model pairs. Collectively, our investigations highlight that while PDXs and PDOs may serve as tractable and transplantable systems for probing the molecular properties of PDAC, these models may best serve selective analyses across different levels of genomic complexity.

2 Article Exome-Wide Association Study of Pancreatic Cancer Risk. 2018

Grant, Robert C / Denroche, Robert E / Borgida, Ayelet / Virtanen, Carl / Cook, Natalie / Smith, Alyssa L / Connor, Ashton A / Wilson, Julie M / Peterson, Gloria / Roberts, Nicholas J / Klein, Alison P / Grimmond, Sean M / Biankin, Andrew / Cleary, Sean / Moore, Malcolm / Lemire, Mathieu / Zogopoulos, George / Stein, Lincoln / Gallinger, Steven. ·Ontario Institute for Cancer Research, Toronto, Canada. · Ontario Pancreas Cancer Study, Toronto, Canada. · Princess Margaret Genomics Centre, Toronto, Canada. · Research Institute of the McGill University Health Centre, Montreal, Canada. · Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota. · Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins Medical Institutions, Baltimore, Maryland. · Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins Medical Institutions, Baltimore, Maryland; Department of Pathology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, Baltimore, Maryland. · University of Melbourne Centre for Cancer Research, Victorian Comprehensive Cancer Centre, Melbourne, Australia. · Wohl Cancer Research Centre, Institute of, Cancer Sciences, University of Glasgow, Glasgow, United Kingdom; West of Scotland Pancreatic Unit, Glasgow Royal Infirmary, Glasgow, United Kingdom; South Western Sydney Clinical School, Faculty of Medicine, University of NSW, Liverpool, Australia. · Ontario Institute for Cancer Research, Toronto, Canada; Ontario Pancreas Cancer Study, Toronto, Canada. · Ontario Institute for Cancer Research, Toronto, Canada; Ontario Pancreas Cancer Study, Toronto, Canada. Electronic address: steven.gallinger@uhn.ca. ·Gastroenterology · Pubmed #29074453.

ABSTRACT: We conducted a case-control exome-wide association study to discover germline variants in coding regions that affect risk for pancreatic cancer, combining data from 5 studies. We analyzed exome and genome sequencing data from 437 patients with pancreatic cancer (cases) and 1922 individuals not known to have cancer (controls). In the primary analysis, BRCA2 had the strongest enrichment for rare inactivating variants (17/437 cases vs 3/1922 controls) (P = 3.27x10

3 Article A renewed model of pancreatic cancer evolution based on genomic rearrangement patterns. 2016

Notta, Faiyaz / Chan-Seng-Yue, Michelle / Lemire, Mathieu / Li, Yilong / Wilson, Gavin W / Connor, Ashton A / Denroche, Robert E / Liang, Sheng-Ben / Brown, Andrew M K / Kim, Jaeseung C / Wang, Tao / Simpson, Jared T / Beck, Timothy / Borgida, Ayelet / Buchner, Nicholas / Chadwick, Dianne / Hafezi-Bakhtiari, Sara / Dick, John E / Heisler, Lawrence / Hollingsworth, Michael A / Ibrahimov, Emin / Jang, Gun Ho / Johns, Jeremy / Jorgensen, Lars G T / Law, Calvin / Ludkovski, Olga / Lungu, Ilinca / Ng, Karen / Pasternack, Danielle / Petersen, Gloria M / Shlush, Liran I / Timms, Lee / Tsao, Ming-Sound / Wilson, Julie M / Yung, Christina K / Zogopoulos, George / Bartlett, John M S / Alexandrov, Ludmil B / Real, Francisco X / Cleary, Sean P / Roehrl, Michael H / McPherson, John D / Stein, Lincoln D / Hudson, Thomas J / Campbell, Peter J / Gallinger, Steven. ·Ontario Institute for Cancer Research, Toronto, Ontario M5G 0A3, Canada. · Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK. · UHN Program in BioSpecimen Sciences, Department of Pathology, University Health Network, Toronto, Ontario M5G 2C4, Canada. · Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 1L7, Canada. · Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada. · Department of Computer Science, University of Toronto, Toronto, Ontario M5S 3G4, Canada. · Eppley Institute for Research in Cancer, Nebraska Medical Center, Omaha, Nebraska 68198, USA. · Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada. · Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, Ontario M5G 2M9, Canada. · Division of Surgical Oncology, Sunnybrook Health Sciences Centre, Odette Cancer Centre, Toronto, Ontario M4N 3M5, Canada. · Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota 55905, USA. · Research Institute of the McGill University Health Centre, Montreal, Québec, Canada, H3H 2L9. · Theoretical Biology and Biophysics (T-6) and Center for Nonlinear Studies, Los Alamos National Laboratory, Los Alamos, New Mexico, USA, 87545. · Epithelial Carcinogenesis Group, Spanish National Cancer Research Centre (CNIO), Madrid 28029, Spain. · Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada. · Department of Surgery, University Health Network, Toronto, Ontario M5G 2C4, Canada. · Department of Haematology, University of Cambridge, Cambridge CB2 0XY, UK. ·Nature · Pubmed #27732578.

ABSTRACT: Pancreatic cancer, a highly aggressive tumour type with uniformly poor prognosis, exemplifies the classically held view of stepwise cancer development. The current model of tumorigenesis, based on analyses of precursor lesions, termed pancreatic intraepithelial neoplasm (PanINs) lesions, makes two predictions: first, that pancreatic cancer develops through a particular sequence of genetic alterations (KRAS, followed by CDKN2A, then TP53 and SMAD4); and second, that the evolutionary trajectory of pancreatic cancer progression is gradual because each alteration is acquired independently. A shortcoming of this model is that clonally expanded precursor lesions do not always belong to the tumour lineage, indicating that the evolutionary trajectory of the tumour lineage and precursor lesions can be divergent. This prevailing model of tumorigenesis has contributed to the clinical notion that pancreatic cancer evolves slowly and presents at a late stage. However, the propensity for this disease to rapidly metastasize and the inability to improve patient outcomes, despite efforts aimed at early detection, suggest that pancreatic cancer progression is not gradual. Here, using newly developed informatics tools, we tracked changes in DNA copy number and their associated rearrangements in tumour-enriched genomes and found that pancreatic cancer tumorigenesis is neither gradual nor follows the accepted mutation order. Two-thirds of tumours harbour complex rearrangement patterns associated with mitotic errors, consistent with punctuated equilibrium as the principal evolutionary trajectory. In a subset of cases, the consequence of such errors is the simultaneous, rather than sequential, knockout of canonical preneoplastic genetic drivers that are likely to set-off invasive cancer growth. These findings challenge the current progression model of pancreatic cancer and provide insights into the mutational processes that give rise to these aggressive tumours.

4 Article Association between Variants in Atopy-Related Immunologic Candidate Genes and Pancreatic Cancer Risk. 2015

Cotterchio, Michelle / Lowcock, Elizabeth / Bider-Canfield, Zoe / Lemire, Mathieu / Greenwood, Celia / Gallinger, Steven / Hudson, Thomas. ·Prevention and Cancer Control, Cancer Care Ontario, Toronto, ON M5G 2L7, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5T 3M7, Canada. · Prevention and Cancer Control, Cancer Care Ontario, Toronto, ON M5G 2L7, Canada. · Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada. · Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC H3T 1E2, Canada. · Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada; Division of General Surgery, Toronto General Hospital, Toronto, ON M5G 2C4, Canada. · Ontario Institute for Cancer Research, Toronto, ON M5G 0A3, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A1, Canada. ·PLoS One · Pubmed #25945796.

ABSTRACT: BACKGROUND: Many epidemiology studies report that atopic conditions such as allergies are associated with reduced pancreas cancer risk. The reason for this relationship is not yet understood. This is the first study to comprehensively evaluate the association between variants in atopy-related candidate genes and pancreatic cancer risk. METHODS: A population-based case-control study of pancreas cancer cases diagnosed during 2011-2012 (via Ontario Cancer Registry), and controls recruited using random digit dialing utilized DNA from 179 cases and 566 controls. Following an exhaustive literature review, SNPs in 180 candidate genes were pre-screened using dbGaP pancreas cancer GWAS data; 147 SNPs in 56 allergy-related immunologic genes were retained and genotyped. Logistic regression was used to estimate age-adjusted odd ratio (AOR) for each variant and false discovery rate was used to adjust Wald p-values for multiple testing. Subsequently, a risk allele score was derived based on statistically significant variants. RESULTS: 18 SNPs in 14 candidate genes (CSF2, DENND1B, DPP10, FLG, IL13, IL13RA2, LRP1B, NOD1, NPSR1, ORMDL3, RORA, STAT4, TLR6, TRA) were significantly associated with pancreas cancer risk. After adjustment for multiple comparisons, two LRP1B SNPs remained statistically significant; for example, LRP1B rs1449477 (AA vs. CC: AOR=0.37, 95% CI: 0.22-0.62; p (adjusted)=0.04). Furthermore, the risk allele score was associated with a significant reduction in pancreas cancer risk (p=0.0007). CONCLUSIONS: Preliminary findings suggest certain atopy-related variants may be associated with pancreas cancer risk. Further studies are needed to replicate this, and to elucidate the biology behind the growing body of epidemiologic evidence suggesting allergies may reduce pancreatic cancer risk.

5 Article Integrated genomic, transcriptomic, and RNA-interference analysis of genes in somatic copy number gains in pancreatic ductal adenocarcinoma. 2013

Samuel, Nardin / Sayad, Azin / Wilson, Gavin / Lemire, Mathieu / Brown, Kevin R / Muthuswamy, Lakshmi / Hudson, Thomas J / Moffat, Jason. ·Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada. ·Pancreas · Pubmed #23851435.

ABSTRACT: OBJECTIVES: This study used an integrated analysis of copy number, gene expression, and RNA interference screens for identification of putative driver genes harbored in somatic copy number gains in pancreatic ductal adenocarcinoma (PDAC). METHODS: Somatic copy number gain data on 60 PDAC genomes were extracted from public data sets to identify genomic loci that are recurrently gained. Array-based data from a panel of 29 human PDAC cell lines were used to quantify associations between copy number and gene expression for the set of genes found in somatic copy number gains. The most highly correlated genes were assessed in a compendium of pooled short hairpin RNA screens on 27 of the same human PDAC cell lines. RESULTS: A catalog of 710 protein-coding and 46 RNA genes mapping to 20 recurrently gained genomic loci were identified. The gene set was further refined through stringent integration of copy number, gene expression, and RNA interference screening data to uncover 34 candidate driver genes. CONCLUSIONS: Among the candidate genes from the integrative analysis, ECT2 was found to have significantly higher essentiality in specific PDAC cell lines with genomic gains at the 3q26.3 locus, which harbors this gene, suggesting that ECT2 may play an oncogenic role in the PDAC neoplastic process.