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Al Zouabi L, Stefanutti M, Roumeliotis S, Le Meur G, Boumard B, Riddiford N, Rubanova N, Bohec M, Gervais L, Servant N, Bardin AJ. Molecular underpinnings and environmental drivers of loss of heterozygosity in Drosophila intestinal stem cells. Cell Rep 2023; 42:113485. [PMID: 38032794 DOI: 10.1016/j.celrep.2023.113485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/29/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
During development and aging, genome mutation leading to loss of heterozygosity (LOH) can uncover recessive phenotypes within tissue compartments. This phenomenon occurs in normal human tissues and is prevalent in pathological genetic conditions and cancers. While studies in yeast have defined DNA repair mechanisms that can promote LOH, the predominant pathways and environmental triggers in somatic tissues of multicellular organisms are not well understood. Here, we investigate mechanisms underlying LOH in intestinal stem cells in Drosophila. Infection with the pathogenic bacteria, Erwinia carotovora carotovora 15, but not Pseudomonas entomophila, increases LOH frequency. Using whole genome sequencing of somatic LOH events, we demonstrate that they arise primarily via mitotic recombination. Molecular features and genetic evidence argue against a break-induced replication mechanism and instead support cross-over via double Holliday junction-based repair. This study provides a mechanistic understanding of mitotic recombination, an important mediator of LOH, and its effects on stem cells in vivo.
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Affiliation(s)
- Lara Al Zouabi
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Marine Stefanutti
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Spyridon Roumeliotis
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Gwenn Le Meur
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Benjamin Boumard
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Nick Riddiford
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Natalia Rubanova
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France; Bioinformatics, Biostatistics, Epidemiology and Computational Systems Unit, Institut Curie, PSL Research University, INSERM U900, 75005 Paris, France
| | - Mylène Bohec
- ICGex Next-Generation Sequencing Platform, Institut Curie, PSL Research University, 75005 Paris, France
| | - Louis Gervais
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Nicolas Servant
- Bioinformatics, Biostatistics, Epidemiology and Computational Systems Unit, Institut Curie, PSL Research University, INSERM U900, 75005 Paris, France
| | - Allison J Bardin
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France.
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de Lima JD, de Paula AGP, Yuasa BS, de Souza Smanioto CC, da Cruz Silva MC, Dos Santos PI, Prado KB, Winter Boldt AB, Braga TT. Genetic and Epigenetic Regulation of the Innate Immune Response to Gout. Immunol Invest 2023; 52:364-397. [PMID: 36745138 DOI: 10.1080/08820139.2023.2168554] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Gout is a disease caused by uric acid (UA) accumulation in the joints, causing inflammation. Two UA forms - monosodium urate (MSU) and soluble uric acid (sUA) have been shown to interact physically with inflammasomes, especially with the nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3), albeit the role of the immune response to UA is poorly understood, given that asymptomatic hyperuricemia does also exist. Macrophage phagocytosis of UA activate NLRP3, lead to cytokines release, and ultimately, lead to chemoattract neutrophils and lymphocytes to the gout flare joint spot. Genetic variants of inflammasome genes and of genes encoding their molecular partners may influence hyperuricemia and gout susceptibility, while also influencing other comorbidities such as metabolic syndrome and cardiovascular diseases. In this review, we summarize the inflammatory responses in acute and chronic gout, specifically focusing on innate immune cell mechanisms and genetic and epigenetic characteristics of participating molecules. Unprecedently, a novel UA binding protein - the neuronal apoptosis inhibitor protein (NAIP) - is suggested as responsible for the asymptomatic hyperuricemia paradox.Abbreviation: β2-integrins: leukocyte-specific adhesion molecules; ABCG2: ATP-binding cassete family/breast cancer-resistant protein; ACR: American college of rheumatology; AIM2: absent in melanoma 2, type of pattern recognition receptor; ALPK1: alpha-protein kinase 1; ANGPTL2: angiopoietin-like protein 2; ASC: apoptosis-associated speck-like protein; BIR: baculovirus inhibitor of apoptosis protein repeat; BIRC1: baculovirus IAP repeat-containing protein 1; BIRC2: baculoviral IAP repeat-containing protein 2; C5a: complement anaphylatoxin; cAMP: cyclic adenosine monophosphate; CARD: caspase activation and recruitment domains; CARD8: caspase recruitment domain-containing protein 8; CASP1: caspase 1; CCL3: chemokine (C-C motif) ligand 3; CD14: cluster of differentiation 14; CD44: cluster of differentiation 44; Cg05102552: DNA-methylation site, usually cytosine followed by guanine nucleotides; contains arbitrary identification code; CIDEC: cell death-inducing DNA fragmentation factor-like effector family; CKD: chronic kidney disease; CNV: copy number variation; CPT1A: carnitine palmitoyl transferase - type 1a; CXCL1: chemokine (CXC motif) ligand 1; DAMPs: damage associated molecular patterns; DC: dendritic cells; DNMT(1): maintenance DNA methyltransferase; eQTL: expression quantitative trait loci; ERK1: extracellular signal-regulated kinase 1; ERK2: extracellular signal-regulated kinase 2; EULAR: European league against rheumatism; GMCSF: granulocyte-macrophage colony-stimulating factor; GWAS: global wide association studies; H3K27me3: tri-methylation at the 27th lysine residue of the histone h3 protein; H3K4me1: mono-methylation at the 4th lysine residue of the histone h3 protein; H3K4me3: tri-methylation at the 4th lysine residue of the histone h3 protein; HOTAIR: human gene located between hoxc11 and hoxc12 on chromosome 12; IκBα: cytoplasmatic protein/Nf-κb transcription inhibitor; IAP: inhibitory apoptosis protein; IFNγ: interferon gamma; IL-1β: interleukin 1 beta; IL-12: interleukin 12; IL-17: interleukin 17; IL18: interleukin 18; IL1R1: interleukin-1 receptor; IL-1Ra: interleukin-1 receptor antagonist; IL-22: interleukin 22; IL-23: interleukin 23; IL23R: interleukin 23 receptor; IL-33: interleukin 33; IL-6: interleukin 6; IMP: inosine monophosphate; INSIG1: insulin-induced gene 1; JNK1: c-jun n-terminal kinase 1; lncRNA: long non-coding ribonucleic acid; LRR: leucine-rich repeats; miR: mature non-coding microRNAs measuring from 20 to 24 nucleotides, animal origin; miR-1: miR followed by arbitrary identification code; miR-145: miR followed by arbitrary identification code; miR-146a: miR followed by arbitrary identification code, "a" stands for mir family; "a" family presents similar mir sequence to "b" family, but different precursors; miR-20b: miR followed by arbitrary identification code; "b" stands for mir family; "b" family presents similar mir sequence to "a" family, but different precursors; miR-221: miR - followed by arbitrary identification code; miR-221-5p: miR followed by arbitrary identification code; "5p" indicates different mature miRNAs generated from the 5' arm of the pre-miRNA hairpin; miR-223: miR followed by arbitrary identification code; miR-223-3p: mir followed by arbitrary identification code; "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; miR-22-3p: miR followed by arbitrary identification code, "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; MLKL: mixed lineage kinase domain-like pseudo kinase; MM2P: inductor of m2-macrophage polarization; MSU: monosodium urate; mTOR: mammalian target of rapamycin; MyD88: myeloid differentiation primary response 88; n-3-PUFAs: n-3-polyunsaturated fatty-acids; NACHT: acronym for NAIP (neuronal apoptosis inhibitor protein), C2TA (MHC class 2 transcription activator), HET-E (incompatibility locus protein from podospora anserina) and TP1 (telomerase-associated protein); NAIP: neuronal apoptosis inhibitory protein (human); Naip1: neuronal apoptosis inhibitory protein type 1 (murine); Naip5: neuronal apoptosis inhibitory protein type 5 (murine); Naip6: neuronal apoptosis inhibitory protein type 6 (murine); NBD: nucleotide-binding domain; Nek7: smallest NIMA-related kinase; NET: neutrophil extracellular traps; Nf-κB: nuclear factor kappa-light-chain-enhancer of activated b cells; NFIL3: nuclear-factor, interleukin 3 regulated protein; NIIMA: network of immunity in infection, malignancy, and autoimmunity; NLR: nod-like receptor; NLRA: nod-like receptor NLRA containing acidic domain; NLRB: nod-like receptor NLRA containing BIR domain; NLRC: nod-like receptor NLRA containing CARD domain; NLRC4: nod-like receptor family CARD domain containing 4; NLRP: nod-like receptor NLRA containing PYD domain; NLRP1: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 1; NLRP12: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 12; NLRP3: nod-like receptor family pyrin domain containing 3; NOD2: nucleotide-binding oligomerization domain; NRBP1: nuclear receptor-binding protein; Nrf2: nuclear factor erythroid 2-related factor 2; OR: odds ratio; P2X: group of membrane ion channels activated by the binding of extracellular; P2X7: p2x purinoceptor 7 gene; p38: member of the mitogen-activated protein kinase family; PAMPs: pathogen associated molecular patters; PBMC: peripheral blood mononuclear cells; PGGT1B: geranylgeranyl transferase type-1 subunit beta; PHGDH: phosphoglycerate dehydrogenase; PI3-K: phospho-inositol; PPARγ: peroxisome proliferator-activated receptor gamma; PPARGC1B: peroxisome proliferative activated receptor, gamma, coactivator 1 beta; PR3: proteinase 3 antigen; Pro-CASP1: inactive precursor of caspase 1; Pro-IL1β: inactive precursor of interleukin 1 beta; PRR: pattern recognition receptors; PYD: pyrin domain; RAPTOR: regulatory associated protein of mTOR complex 1; RAS: renin-angiotensin system; REDD1: regulated in DNA damage and development 1; ROS: reactive oxygen species; rs000*G: single nuclear polymorphism, "*G" is related to snp where replaced nucleotide is guanine, usually preceded by an id number; SLC2A9: solute carrier family 2, member 9; SLC7A11: solute carrier family 7, member 11; SMA: smooth muscular atrophy; Smac: second mitochondrial-derived activator of caspases; SNP: single nuclear polymorphism; Sp3: specificity protein 3; ST2: serum stimulation-2; STK11: serine/threonine kinase 11; sUA: soluble uric acid; Syk: spleen tyrosine kinase; TAK1: transforming growth factor beta activated kinase; Th1: type 1 helper T cells; Th17: type 17 helper T cells; Th2: type 2 helper T cells; Th22: type 22 helper T cells; TLR: tool-like receptor; TLR2: toll-like receptor 2; TLR4: toll-like receptor 4; TNFα: tumor necrosis factor alpha; TNFR1: tumor necrosis factor receptor 1; TNFR2: tumor necrosis factor receptor 2; UA: uric acid; UBAP1: ubiquitin associated protein; ULT: urate-lowering therapy; URAT1: urate transporter 1; VDAC1: voltage-dependent anion-selective channel 1.
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Affiliation(s)
- Jordana Dinorá de Lima
- Microbiology, Parasitology and Pathology Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | | | - Bruna Sadae Yuasa
- Microbiology, Parasitology and Pathology Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | | | - Maria Clara da Cruz Silva
- Microbiology, Parasitology and Pathology Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | | | - Karin Braun Prado
- Genetics Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | - Angelica Beate Winter Boldt
- Program of Internal Medicine, Universidade Federal do Parana (UFPR), Curitiba, Brazil
- Genetics Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | - Tárcio Teodoro Braga
- Microbiology, Parasitology and Pathology Program, Universidade Federal do Parana (UFPR), Curitiba, Brazil
- Biosciences and Biotechnology Program, Instituto Carlos Chagas (ICC), Fiocruz-Parana, Brazil
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Erola P, Torabi K, Miró R, Camps J. The non-random landscape of somatically-acquired uniparental disomy in cancer. Oncotarget 2019; 10:3982-3984. [PMID: 31258837 PMCID: PMC6592296 DOI: 10.18632/oncotarget.26987] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 05/14/2019] [Indexed: 11/25/2022] Open
Affiliation(s)
- Pau Erola
- CRUK Integrative Cancer Epidemiology Programme, MRC Integrative Epidemiology Unit, University of Bristol, Bristol, BS8 2BN, UK
| | - Keyvan Torabi
- Gastrointestinal and Pancreatic Oncology Group, Institut D’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Catalonia, 08036, Spain
| | - Rosa Miró
- Unitat de Biologia Cel·lular i Genètica Mèdica, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, 08193, Spain
| | - Jordi Camps
- Gastrointestinal and Pancreatic Oncology Group, Institut D’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Catalonia, 08036, Spain
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4
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Torabi K, Erola P, Alvarez-Mora MI, Díaz-Gay M, Ferrer Q, Castells A, Castellví-Bel S, Milà M, Lozano JJ, Miró R, Ried T, Ponsa I, Camps J. Quantitative analysis of somatically acquired and constitutive uniparental disomy in gastrointestinal cancers. Int J Cancer 2018; 144:513-524. [PMID: 30350313 PMCID: PMC6635747 DOI: 10.1002/ijc.31936] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 08/31/2018] [Accepted: 10/02/2018] [Indexed: 12/20/2022]
Abstract
Somatically acquired uniparental disomies (aUPDs) are frequent events in solid tumors and have been associated with cancer‐related genes. Studies assessing their functional consequences across several cancer types are therefore necessary. Here, we aimed at integrating aUPD profiles with the mutational status of cancer‐related genes in a tumor‐type specific manner. Using TCGA datasets for 1,032 gastrointestinal cancers, including colon (COAD), rectum (READ), stomach (STAD), esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC), we show a non‐random distribution of aUPD, suggesting the existence of a cancer‐specific landscape of aUPD events. Our analysis indicates that aUPD acts as a “second hit” in Knudson's model in order to achieve biallelic inactivation of tumor suppressor genes. In particular, APC, ARID1A and NOTCH1 were recurrently inactivated by the presence of homozygous mutation as a consequence of aUPD in COAD and READ, STAD and ESCC, respectively. Furthermore, while TP53 showed inactivation caused by aUPD at chromosome arm 17p across all tumor types, copy number losses at this genomic position were also frequent. By experimental and computationally inferring genome ploidy, we demonstrate that an increased number of aUPD events, both affecting the whole chromosome or segments of it, were present in highly aneuploid genomes compared to near‐diploid tumors. Finally, the presence of mosaic UPD was detected at a higher frequency in DNA extracted from peripheral blood lymphocytes of patients with colorectal cancer compared to healthy individuals. In summary, our study defines specific profiles of aUPD in gastrointestinal cancers and provides unequivocal evidence of their relevance in cancer. What's new? Somatically acquired uniparental disomies (aUPDs), in which two copies of a chromosome originate from the same parent, have been documented in various human cancers. Here, the authors examined the frequency of aUPDs in different gastrointestinal cancer types. Events involving aUPDs were found to occur at high incidence in gastrointestinal cancers and at increased frequency particularly in highly aneuploid genomes. The data also reveal a nonrandom distribution of aUPDs, with evidence of biallelic inactivation of tumor suppressor genes and activation of oncogenes in a tumor type‐specific manner. The findings suggest that aUPDs are functionally relevant in gastrointestinal malignancies.
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Affiliation(s)
- Keyvan Torabi
- Gastrointestinal and Pancreatic Oncology Group, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Catalonia, Spain.,Unitat de Biologia Cel·lular i Genètica Mèdica, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
| | - Pau Erola
- Bioinformatics Unit, CIBEREHD, Barcelona, Catalonia, Spain.,Roslin Institute, University of Edinburgh, Midlothian, Scotland, United Kingdom
| | - Maria Isabel Alvarez-Mora
- Biochemistry and Molecular Genetics Department, Hospital Clínic, IDIBAPS, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Catalonia, Spain
| | - Marcos Díaz-Gay
- Gastrointestinal and Pancreatic Oncology Group, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Catalonia, Spain
| | - Queralt Ferrer
- Gastrointestinal and Pancreatic Oncology Group, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Catalonia, Spain
| | - Antoni Castells
- Gastrointestinal and Pancreatic Oncology Group, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Catalonia, Spain
| | - Sergi Castellví-Bel
- Gastrointestinal and Pancreatic Oncology Group, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Catalonia, Spain
| | - Montserrat Milà
- Biochemistry and Molecular Genetics Department, Hospital Clínic, IDIBAPS, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Catalonia, Spain
| | | | - Rosa Miró
- Unitat de Biologia Cel·lular i Genètica Mèdica, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain.,Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
| | - Thomas Ried
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Immaculada Ponsa
- Unitat de Biologia Cel·lular i Genètica Mèdica, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain.,Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
| | - Jordi Camps
- Gastrointestinal and Pancreatic Oncology Group, Institut D'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Catalonia, Spain.,Unitat de Biologia Cel·lular i Genètica Mèdica, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
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Houle AA, Gibling H, Lamaze FC, Edgington HA, Soave D, Fave MJ, Agbessi M, Bruat V, Stein LD, Awadalla P. Aberrant PRDM9 expression impacts the pan-cancer genomic landscape. Genome Res 2018; 28:1611-1620. [PMID: 30341163 PMCID: PMC6211651 DOI: 10.1101/gr.231696.117] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 10/04/2018] [Indexed: 12/15/2022]
Abstract
The binding of PRDM9 to chromatin is a key step in the induction of DNA double-strand breaks associated with meiotic recombination hotspots; it is normally expressed solely in germ cells. We interrogated 1879 cancer samples in 39 different cancer types and found that PRDM9 is unexpectedly expressed in 20% of these tumors even after stringent gene homology correction. The expression levels of PRDM9 in tumors are significantly higher than those found in healthy neighboring tissues and in healthy nongerm tissue databases. Recurrently mutated regions located within 5 Mb of the PRDM9 loci, as well as differentially expressed genes in meiotic pathways, correlate with PRDM9 expression. In samples with aberrant PRDM9 expression, structural variant breakpoints frequently neighbor the DNA motif recognized by PRDM9, and there is an enrichment of structural variants at sites of known meiotic PRDM9 activity. This study is the first to provide evidence of an association between aberrant expression of the meiosis-specific gene PRDM9 with genomic instability in cancer.
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Affiliation(s)
- Armande Ang Houle
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada.,University of Toronto, Department of Molecular Genetics, Toronto, Ontario M5S 1A8, Canada
| | - Heather Gibling
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada.,University of Toronto, Department of Molecular Genetics, Toronto, Ontario M5S 1A8, Canada
| | - Fabien C Lamaze
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada.,University of Toronto, Department of Molecular Genetics, Toronto, Ontario M5S 1A8, Canada
| | - Hilary A Edgington
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada.,University of Toronto, Department of Molecular Genetics, Toronto, Ontario M5S 1A8, Canada
| | - David Soave
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada
| | - Marie-Julie Fave
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada
| | - Mawusse Agbessi
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada
| | - Vanessa Bruat
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada
| | - Lincoln D Stein
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada.,University of Toronto, Department of Molecular Genetics, Toronto, Ontario M5S 1A8, Canada
| | - Philip Awadalla
- Ontario Institute for Cancer Research, Department of Computational Biology, Toronto, Ontario M5G 0A3, Canada.,University of Toronto, Department of Molecular Genetics, Toronto, Ontario M5S 1A8, Canada
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Abstract
Somatic recombination is essential to protect genomes of somatic cells from DNA damage but it also has important clinical implications, as it is a driving force of tumorigenesis leading to inactivation of tumor suppressor genes. Despite this importance, our knowledge about somatic recombination in adult tissues remains very limited. Our recent work, using the Drosophila adult midgut has demonstrated that spontaneous events of mitotic recombination accumulate in aging adult intestinal stem cells and result in frequent loss of heterozygosity (LOH). In this Extra View article, we provide further data supporting long-track chromosome LOH and discuss potential mechanisms involved in the process. In addition, we further discuss relevant questions surrounding somatic recombination and how the mechanisms and factors influencing somatic recombination in adult tissues can be explored using the Drosophila midgut model.
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Affiliation(s)
- Katarzyna Siudeja
- a Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis group , Paris , France , Sorbonne Universités, UPMC Univ Paris 6 , Paris , France
| | - Allison J Bardin
- a Institut Curie, PSL Research University, CNRS UMR 3215, INSERM U934, Stem Cells and Tissue Homeostasis group , Paris , France , Sorbonne Universités, UPMC Univ Paris 6 , Paris , France
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7
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Torabi K, Miró R, Fernández-Jiménez N, Quintanilla I, Ramos L, Prat E, del Rey J, Pujol N, Killian JK, Meltzer PS, Fernández PL, Ried T, Lozano JJ, Camps J, Ponsa I. Patterns of somatic uniparental disomy identify novel tumor suppressor genes in colorectal cancer. Carcinogenesis 2015; 36:1103-10. [PMID: 26243311 PMCID: PMC4598814 DOI: 10.1093/carcin/bgv115] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 07/06/2015] [Accepted: 07/29/2015] [Indexed: 01/17/2023] Open
Abstract
Colorectal cancer (CRC) is characterized by specific patterns of copy number alterations (CNAs), which helped with the identification of driver oncogenes and tumor suppressor genes (TSGs). More recently, the usage of single nucleotide polymorphism arrays provided information of copy number neutral loss of heterozygosity, thus suggesting the occurrence of somatic uniparental disomy (UPD) and uniparental polysomy (UPP) events. The aim of this study is to establish an integrative profiling of recurrent UPDs/UPPs and CNAs in sporadic CRC. Our results indicate that regions showing high frequencies of UPD/UPP mostly coincide with regions typically involved in genomic losses. Among them, chromosome arms 3p, 5q, 9q, 10q, 14q, 17p, 17q, 20p, 21q and 22q preferentially showed UPDs/UPPs over genomic losses suggesting that tumor cells must maintain the disomic state of certain genes to favor cellular fitness. A meta-analysis using over 300 samples from The Cancer Genome Atlas confirmed our findings. Several regions affected by recurrent UPDs/UPPs contain well-known TSGs, as well as novel candidates such as ARID1A, DLC1, TCF7L2 and DMBT1. In addition, VCAN, FLT4, SFRP1 and GAS7 were also frequently involved in regions of UPD/UPP and displayed high levels of methylation. Finally, sequencing and fluorescence in situ hybridization analysis of the gene APC underlined that a somatic UPD event might represent the second hit to achieve biallelic inactivation of this TSG in colorectal tumors. In summary, our data define a profile of somatic UPDs/UPPs in sporadic CRC and highlights the importance of these events as a mechanism to achieve the inactivation of TSGs.
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Affiliation(s)
- Keyvan Torabi
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain
| | - Rosa Miró
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain
| | - Nora Fernández-Jiménez
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Present address: Epigenetics Group, International Agency for Research on Cancer 69008, Lyon, France
| | - Isabel Quintanilla
- Gastrointestinal and Pancreatic Oncology Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Catalonia 08036, Spain
| | - Laia Ramos
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Present address: Unitat de Genòmica i Bioinformàtica, Institut de Medicina Predictiva i Personalitzada del Càncer (IMPPC), Badalona, Catalonia 08916, Spain
| | - Esther Prat
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Present address: Laboratori de Genètica Molecular, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Hospitalet de Llobregat, Catalonia 08908, Spain
| | - Javier del Rey
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain
| | - Núria Pujol
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain
| | - J Keith Killian
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Paul S Meltzer
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Pedro Luis Fernández
- Department of Pathology, Hospital Clínic/IDIBAPS, Universitat de Barcelona, Barcelona, Catalonia 08036, Spain and
| | - Thomas Ried
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Juan José Lozano
- Bioinformatics Unit, CIBERehd, Barcelona, Catalonia 08036, Spain
| | - Jordi Camps
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Gastrointestinal and Pancreatic Oncology Group, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Catalonia 08036, Spain, Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Immaculada Ponsa
- Unitat de Biologia Cellular i Genètica Mèdica, Departament de Biologia Cellular, Fisiologia i Immunologia, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Catalonia 08193, Spain,
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8
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Karambataki M, Malousi A, Kouidou S. Risk-associated coding synonymous SNPs in type 2 diabetes and neurodegenerative diseases: genetic silence and the underrated association with splicing regulation and epigenetics. Mutat Res 2014; 770:85-93. [PMID: 25771874 DOI: 10.1016/j.mrfmmm.2014.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 09/15/2014] [Accepted: 09/16/2014] [Indexed: 06/04/2023]
Abstract
Single nucleotide polymorphisms (SNPs) are tentatively critical with regard to disease predisposition, but coding synonymous SNPs (sSNPs) are generally considered "neutral". Nevertheless, sSNPs in serine/arginine-rich (SR) and splice-site (SS) exonic splicing enhancers (ESEs) or in exonic CpG methylation targets, could be decisive for splicing, particularly in aging-related conditions, where mis-splicing is frequently observed. We presently identified 33 genes T2D-related and 28 related to neurodegenerative diseases, by investigating the impact of the corresponding coding sSNPs on splicing and using gene ontology data and computational tools. Potentially critical (prominent) sSNPs comply with the following criteria: changing the splicing potential of prominent SR-ESEs or of significant SS-ESEs by >1.5 units (Δscore), or formation/deletion of ESEs with maximum splicing score. We also noted the formation/disruption of CpGs (tentative methylation sites of epigenetic sSNPs). All disease association studies involving sSNPs are also reported. Only 21/670 coding SNPs, mostly epigenetic, reported in 33 T2D-related genes, were found to be prominent coding synonymous. No prominent sSNPs have been recorded in three key T2D-related genes (GCGR, PPARGC1A, IGF1). Similarly, 20/366 coding synonymous were identified in ND related genes, mostly epigenetic. Meta-analysis showed that 17 of the above prominent sSNPs were previously investigated in association with various pathological conditions. Three out of four sSNPs (all epigenetic) were associated with T2D and one with NDs (branch site sSNP). Five were associated with other or related pathological conditions. None of the four sSNPs introducing new ESEs was found to be disease-associated. sSNPs introducing smaller Δscore changes (<1.5) in key proteins (INSR, IRS1, DISC1) were also correlated to pathological conditions. This data reveals that genetic variation in splicing-regulatory and particularly CpG sites might be related to disease predisposition and that in-silico analysis is useful for identifying sSNPs, which might be falsely identified as silent or synonymous.
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Affiliation(s)
- M Karambataki
- Lab of Biological Chemistry, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - A Malousi
- Lab of Biological Chemistry, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - S Kouidou
- Lab of Biological Chemistry, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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9
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Sant'Anna JR, Yajima JPRS, Rosada LJ, Franco CCS, Prioli AJ, Della-Rosa VA, Mathias PCF, Castro-Prado MAA. Metformin's performance in in vitro and in vivo genetic toxicology studies. Exp Biol Med (Maywood) 2013; 238:803-10. [PMID: 23788173 DOI: 10.1177/1535370213480744] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Metformin is a hypoglycemiant drug prescribed for the treatment and control of the type 2 diabetes mellitus. Recently, the potential efficacy of this antidiabetic drug as an anticancer agent has been demonstrated in various mammalian cancer cells. This report evaluates the mutagenic as well as the recombinogenic potentials of the metformin drug in therapeutically relevant plasma concentrations (12.5 µM, 25.0 µM or 50.0 µM). Since the loss of heterozygosity is a process associated with carcinogenesis, the recombinogenic potential of such a drug was evaluated by the homozygotization assay using a heterozygous diploid strain of Aspergillus nidulans. The homozigotization indices (HI) for the genetic markers from the metformin-treated diploids were not statistically different from the negative control (non-treated diploids). For the first time, this indicated a lack of recombinogenic activity of the antidiabetic drug. The mutagenic potential of the metformin drug was evaluated by the chromosome aberrations and the micronuclei tests in human lymphocytes cultures. The metformin drug did not show any significant increase either in the numerical or in the structural chromosome aberrations and did not affect significantly the mitotic index when compared to the negative control. In the in vitro micronucleus test, the drug did not increase the number of micronuclei or nuclear buds when compared with the negative control. The data in this study suggest that the metformin drug is not a secondary cancer inducer, since it has neither showed recombinogenic nor mutagenic activities when used in pharmacological concentrations.
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Affiliation(s)
- Juliane R Sant'Anna
- Laboratório de Genética de Microorganismos e Mutagênese, Departamento de Biotecnologia, Genética e Biologia Celular, Universidade Estadual de Maringá, 87020-900, Maringá, PR, Brazil
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10
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Abstract
Background: Polymorphic variation at the 5p15.33 (TERT–CLPTM1L) locus is associated
with the risk of many cancers but a relationship with colorectal cancer (CRC) risk has
yet to be defined. Methods: We used data from six genome-wide association studies (GWAS) of CRC, linkage
disequilibrium mapping and imputation, to examine the relationship between 73
single-nucleotide polymorphisms at 5p15.33 and CRC risk in detail. Results: rs2736100, which localises to intron 2 of TERT, provided the strongest
evidence of an association with CRC (P=2.28 ×
10−4). The association was also shown in an independent series of
10 047 CRC cases and 6918 controls (P=0.02). A meta-analysis of
all seven studies (totalling 16 039 cases, 16 430 controls) provided
increased evidence of association (P=2.49 × 10−5;
per allele odds ratio=1.07). The association of rs2736100 on CRC risk was shown
to be independent of 15 low-penetrance variants previously identified. Conclusion: The rs2736100 association demonstrates an influence of variation at 5p15.33 on CRC risk
and further evidence that the 5p15.33 (TERT–CLPTM1L) locus has
pleiotropic effects (reflecting generic or lineage-specific effects) on cancer risk.
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11
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Lambert SR, Harwood CA, Purdie KJ, Gulati A, Matin RN, Romanowska M, Cerio R, Kelsell DP, Leigh IM, Proby CM. Metastatic cutaneous squamous cell carcinoma shows frequent deletion in the protein tyrosine phosphatase receptor Type D gene. Int J Cancer 2011; 131:E216-26. [DOI: 10.1002/ijc.27333] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 10/06/2011] [Indexed: 11/08/2022]
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12
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SNP array analysis of leukemic relapse samples after allogeneic hematopoietic stem cell transplantation with a sibling donor identifies meiotic recombination spots and reveals possible correlation with the breakpoints of acquired genetic aberrations. Leukemia 2011; 25:1358-61. [DOI: 10.1038/leu.2011.79] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Roehl AC, Vogt J, Mussotter T, Zickler AN, Spöti H, Högel J, Chuzhanova NA, Wimmer K, Kluwe L, Mautner VF, Cooper DN, Kehrer-Sawatzki H. Intrachromosomal mitotic nonallelic homologous recombination is the major molecular mechanism underlying type-2 NF1 deletions. Hum Mutat 2011; 31:1163-73. [PMID: 20725927 DOI: 10.1002/humu.21340] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Nonallelic homologous recombination (NAHR) is responsible for the recurrent rearrangements that give rise to genomic disorders. Although meiotic NAHR has been investigated in multiple contexts, much less is known about mitotic NAHR despite its importance for tumorigenesis. Because type-2 NF1 microdeletions frequently result from mitotic NAHR, they represent a good model in which to investigate the features of mitotic NAHR. We have used microsatellite analysis and SNP arrays to distinguish between the various alternative recombinational possibilities, thereby ascertaining that 17 of 18 type-2 NF1 deletions, with breakpoints in the SUZ12 gene and its highly homologous pseudogene, originated via intrachromosomal recombination. This high proportion of intrachromosomal NAHR causing somatic type-2 NF1 deletions contrasts with the interchromosomal origin of germline type-1 NF1 microdeletions, whose breakpoints are located within the NF1-REPs (low-copy repeats located adjacent to the SUZ12 sequences). Further, meiotic NAHR causing type-1 NF1 deletions occurs within recombination hotspots characterized by high GC-content and DNA duplex stability, whereas the type-2 breakpoints associated with the mitotic NAHR events investigated here do not cluster within hotspots and are located within regions of significantly lower GC-content and DNA stability. Our findings therefore point to fundamental mechanistic differences between the determinants of mitotic and meiotic NAHR.
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14
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Franco CCS, Castro-Prado J, Rosada LJ, Sant'Anna JR, Castro-Prado MAA. Mitotic recombination: a genotoxic effect of the antidepressant citalopram in Aspergillus nidulans. Exp Biol Med (Maywood) 2010; 235:1257-62. [PMID: 20851831 DOI: 10.1258/ebm.2010.010159] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This report evaluates the potential of the antidepressant drug citalopram to induce homozygotization of genes previously present in a heterozygous condition, by homologous recombination. In order to address this question, a heterozygous diploid strain of the filamentous fungus Aspergillus nidulans and the homozygotization assay were utilized. Non-cytotoxic concentrations of citalopram (50, 75 and 100 μmol/L) showed a strong recombinogenic effect in A. nidulans, inducing homozygosis of the diploid strain's nutritional markers. The genetic markers exhibited homozygotization index (HI) rates higher than 2.0 and significantly different from HI control ones. Since citalopram has been previously characterized as a DNA synthesis inhibitor, the recombinogenic potential of this antidepressant in A. nidulans may be associated with the recombinational repair of citalopram-induced DNA strand breaks.
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Affiliation(s)
- Claudinéia C S Franco
- Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Avenida Colombo 5790, Bloco H67. Maringá, Paraná 87020-900, Brazil
| | - Juliana Castro-Prado
- Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Avenida Colombo 5790, Bloco H67. Maringá, Paraná 87020-900, Brazil
| | - Lúcia J Rosada
- Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Avenida Colombo 5790, Bloco H67. Maringá, Paraná 87020-900, Brazil
| | - Juliane R Sant'Anna
- Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Avenida Colombo 5790, Bloco H67. Maringá, Paraná 87020-900, Brazil
| | - Marialba A A Castro-Prado
- Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Avenida Colombo 5790, Bloco H67. Maringá, Paraná 87020-900, Brazil
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15
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Sickle cell disease resulting from uniparental disomy in a child who inherited sickle cell trait. Blood 2010; 116:2822-5. [PMID: 20595515 DOI: 10.1182/blood-2010-05-284331] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Sickle cell disease (SCD) is a classic example of a disorder with recessive Mendelian inheritance, in which each parent contributes one mutant allele to an affected offspring. However, there are exceptions to that rule. We describe here the first reported case of conversion of inherited sickle cell trait to SCD by uniparental disomy (UPD) resulting in mosaicism for SS and AS erythrocytes. A 14-year-old boy presented with splenomegaly and hemolysis. Although his father has sickle cell trait, his mother has no abnormal hemoglobin (Hb). DNA sequencing, performed to rule out Hb S/β-thalassemia, detected homozygous Hb SS. Further studies revealed mosaic UPD of the β-globin locus, more SS erythroid progenitors than AS, but a reverse ratio of erythrocytes resulting from the survival advantage of AS erythrocytes. This report exemplifies non-Mendelian genetics wherein a patient who inherited sickle cell trait has mild SCD resulting from postzygotic mitotic recombination leading to UPD.
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16
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Abstract
Single nucleotide polymorphism arrays (SNP-A) have recently been widely applied as a powerful karyotyping tool in numerous translational cancer studies. SNP-A complements traditional metaphase cytogenetics with the unique ability to delineate a previously hidden chromosomal defect, copy neutral loss of heterozygosity (CN-LOH). Emerging data demonstrate that selected hematologic malignancies exhibit abundant CN-LOH, often in the setting of a normal metaphase karyotype and no previously identified clonal marker. In this review, we explore emerging biologic and clinical features of CN-LOH relevant to hematologic malignancies. In myeloid malignancies, CN-LOH has been associated with the duplication of oncogenic mutations with concomitant loss of the normal allele. Examples include JAK2, MPL, c-KIT, and FLT3. More recent investigations have focused on evaluation of candidate genes contained in common CN-LOH and deletion regions and have led to the discovery of tumor suppressor genes, including c-CBL and family members, as well as TET2. Investigations into the underlying mechanisms generating CN-LOH have great promise for elucidating general cancer mechanisms. We anticipate that further detailed characterization of CN-LOH lesions will probably facilitate our discovery of a more complete set of pathogenic molecular lesions, disease and prognosis markers, and better understanding of the initiation and progression of hematologic malignancies.
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