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Wang W, Org T, Montel-Hagen A, Pioli PD, Duan D, Israely E, Malkin D, Su T, Flach J, Kurdistani SK, Schiestl RH, Mikkola HKA. MEF2C protects bone marrow B-lymphoid progenitors during stress haematopoiesis. Nat Commun 2016; 7:12376. [PMID: 27507714 PMCID: PMC4987520 DOI: 10.1038/ncomms12376] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Accepted: 06/27/2016] [Indexed: 12/19/2022] Open
Abstract
DNA double strand break (DSB) repair is critical for generation of B-cell receptors, which are pre-requisite for B-cell progenitor survival. However, the transcription factors that promote DSB repair in B cells are not known. Here we show that MEF2C enhances the expression of DNA repair and recombination factors in B-cell progenitors, promoting DSB repair, V(D)J recombination and cell survival. Although Mef2c-deficient mice maintain relatively intact peripheral B-lymphoid cellularity during homeostasis, they exhibit poor B-lymphoid recovery after sub-lethal irradiation and 5-fluorouracil injection. MEF2C binds active regulatory regions with high-chromatin accessibility in DNA repair and V(D)J genes in both mouse B-cell progenitors and human B lymphoblasts. Loss of Mef2c in pre-B cells reduces chromatin accessibility in multiple regulatory regions of the MEF2C-activated genes. MEF2C therefore protects B lymphopoiesis during stress by ensuring proper expression of genes that encode DNA repair and B-cell factors.
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Affiliation(s)
- Wenyuan Wang
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, California 90095, USA.,Molecular Biology Institute, UCLA, Los Angeles, California 90095, USA
| | - Tonis Org
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, California 90095, USA.,Institute of Molecular and Cell Biology, University of Tartu, Tartu 51010, Estonia
| | - Amélie Montel-Hagen
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, California 90095, USA
| | - Peter D Pioli
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, California 90095, USA
| | - Dan Duan
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, California 90095, USA
| | - Edo Israely
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, California 90095, USA
| | - Daniel Malkin
- Department of Molecular Toxicology, UCLA, Los Angeles, California 90095, USA.,Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095, USA
| | - Trent Su
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
| | - Johanna Flach
- The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California San Francisco, San Francisco, California 94143, USA
| | - Siavash K Kurdistani
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
| | - Robert H Schiestl
- Department of Molecular Toxicology, UCLA, Los Angeles, California 90095, USA.,Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095, USA
| | - Hanna K A Mikkola
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, California 90095, USA.,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, California 90095, USA.,Molecular Biology Institute, UCLA, Los Angeles, California 90095, USA.,Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095, USA
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52
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Tsouroula K, Furst A, Rogier M, Heyer V, Maglott-Roth A, Ferrand A, Reina-San-Martin B, Soutoglou E. Temporal and Spatial Uncoupling of DNA Double Strand Break Repair Pathways within Mammalian Heterochromatin. Mol Cell 2016; 63:293-305. [PMID: 27397684 DOI: 10.1016/j.molcel.2016.06.002] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 05/11/2016] [Accepted: 05/31/2016] [Indexed: 12/13/2022]
Abstract
Repetitive DNA is packaged into heterochromatin to maintain its integrity. We use CRISPR/Cas9 to induce DSBs in different mammalian heterochromatin structures. We demonstrate that in pericentric heterochromatin, DSBs are positionally stable in G1 and recruit NHEJ factors. In S/G2, DSBs are resected and relocate to the periphery of heterochromatin, where they are retained by RAD51. This is independent of chromatin relaxation but requires end resection and RAD51 exclusion from the core. DSBs that fail to relocate are engaged by NHEJ or SSA proteins. We propose that the spatial disconnection between end resection and RAD51 binding prevents the activation of mutagenic pathways and illegitimate recombination. Interestingly, in centromeric heterochromatin, DSBs recruit both NHEJ and HR proteins throughout the cell cycle. Our results highlight striking differences in the recruitment of DNA repair factors between pericentric and centromeric heterochromatin and suggest a model in which the commitment to specific DNA repair pathways regulates DSB position.
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Affiliation(s)
- Katerina Tsouroula
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Centre National de Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France
| | - Audrey Furst
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Centre National de Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France
| | - Melanie Rogier
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Centre National de Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France
| | - Vincent Heyer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Centre National de Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France
| | - Anne Maglott-Roth
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Centre National de Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France
| | - Alexia Ferrand
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland
| | - Bernardo Reina-San-Martin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Centre National de Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France.
| | - Evi Soutoglou
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U964, 67404 Illkirch, France; Centre National de Recherche Scientifique, UMR7104, 67404 Illkirch, France; Université de Strasbourg, 67081 Strasbourg, France.
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53
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Laffitte MCN, Leprohon P, Hainse M, Légaré D, Masson JY, Ouellette M. Chromosomal Translocations in the Parasite Leishmania by a MRE11/RAD50-Independent Microhomology-Mediated End Joining Mechanism. PLoS Genet 2016; 12:e1006117. [PMID: 27314941 PMCID: PMC4912120 DOI: 10.1371/journal.pgen.1006117] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 05/20/2016] [Indexed: 01/15/2023] Open
Abstract
The parasite Leishmania often relies on gene rearrangements to survive stressful environments. However, safeguarding a minimum level of genome integrity is important for cell survival. We hypothesized that maintenance of genomic integrity in Leishmania would imply a leading role of the MRE11 and RAD50 proteins considering their role in DNA repair, chromosomal organization and protection of chromosomes ends in other organisms. Attempts to generate RAD50 null mutants in a wild-type background failed and we provide evidence that this gene is essential. Remarkably, inactivation of RAD50 was possible in a MRE11 null mutant that we had previously generated, providing good evidence that RAD50 may be dispensable in the absence of MRE11. Inactivation of the MRE11 and RAD50 genes led to a decreased frequency of homologous recombination and analysis of the null mutants by whole genome sequencing revealed several chromosomal translocations. Sequencing of the junction between translocated chromosomes highlighted microhomology sequences at the level of breakpoint regions. Sequencing data also showed a decreased coverage at subtelomeric locations in many chromosomes in the MRE11-/-RAD50-/- parasites. This study demonstrates an MRE11-independent microhomology-mediated end-joining mechanism and a prominent role for MRE11 and RAD50 in the maintenance of genomic integrity. Moreover, we suggest the possible involvement of RAD50 in subtelomeric regions stability. The parasite Leishmania relies on gene rearrangements to survive stressful conditions. However, maintaining a minimum level of genomic integrity is crucial for cell survival. Studies in other organisms have provided evidence that the DNA repair proteins MRE11 and RAD50 are involved in chromosomes organization, protection of chromosomes ends and therefore in the maintenance of genomic integrity. In this manuscript, we present the conditional inactivation of the Leishmania infantum RAD50 gene that was only possible in MRE11 deficient cells and suggest the genetic background is crucial for RAD50 inactivation. We demonstrate the occurrence of chromosomal translocations in the MRE11 and RAD50 deficient cells and described a MRE11-independent microhomology-mediated end-joining mechanism at the level of translocation breakpoints. We also suggest a possible involvement of RAD50 in subtelomeric regions stability. Our results highlight that both MRE11 and RAD50 are important for the maintenance of genomic integrity in Leishmania.
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Affiliation(s)
| | - Philippe Leprohon
- Centre de Recherche en Infectiologie, CRCHU de Québec, Québec City, Québec, Canada
| | - Maripier Hainse
- Genome Stability Laboratory, CRCHU de Québec, Pavillon HDQ Oncology axis, Québec City, Québec, Canada
| | - Danielle Légaré
- Centre de Recherche en Infectiologie, CRCHU de Québec, Québec City, Québec, Canada
| | - Jean-Yves Masson
- Genome Stability Laboratory, CRCHU de Québec, Pavillon HDQ Oncology axis, Québec City, Québec, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Centre de recherche sur le Cancer, Université Laval, Québec City, Québec, Canada
| | - Marc Ouellette
- Centre de Recherche en Infectiologie, CRCHU de Québec, Québec City, Québec, Canada
- * E-mail:
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54
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Adi-Kusumo F, Wiraya A. Mathematical modeling of the cells repair regulations in Nasopharyngeal carcinoma. Math Biosci 2016; 277:108-16. [PMID: 27140528 DOI: 10.1016/j.mbs.2016.04.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 04/11/2016] [Accepted: 04/24/2016] [Indexed: 11/28/2022]
Abstract
Nasopharyngeal Carcinoma (NPC) is a malignant cancer which is caused by the activation of Epstein-Barr Virus (EBV) via some external factors. In the cells repair regulations, the p53 gene mutation can be used as the early indication of the NPC growth. The NPC growth is due to the DNA damage accumulation caused by the EBV infection. In this paper we construct the cells repair regulations model to characterize the NPC growth. The model is a 15 dimensional of first order ODE system and consists the proteins and enzymes reactions. We do some numerical simulations to show the inactivation of the phosphorylated and acetylated p53, and the chromosomal instability of p53 gene, which can be used as the earlier stage detection of NPC.
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Affiliation(s)
- Fajar Adi-Kusumo
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Indonesia.
| | - Ario Wiraya
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Indonesia.
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55
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Procalcitonin as a biomarker for infection-related mortality in cancer patients. Curr Opin Support Palliat Care 2016; 9:168-73. [PMID: 25872114 DOI: 10.1097/spc.0000000000000142] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE OF REVIEW Infectious diseases are the second leading cause of death following direct cancer-related complications in the field of oncology. Clinical studies using the classic inflammatory biomarkers, C-reactive protein, erythrocyte sedimentation rate, leukocytosis, and thrombocytosis fail to show a significant correlation between these biomarkers and infection-related mortality. It is therefore crucial to define new biomarkers that are not affected by the primary cancer and precisely show the severity of the infection to help in the decision-making process. RECENT FINDINGS A significant increase in the number of cancer patients in the past decades has created an exponential increase in the number of immunocompromised patients. Preemptive and typically unnecessary usage of broad-spectrum antibiotics is common during the treatment of these patients and may result in an increase in multidrug-resistant microbial strains. Recent clinical studies suggest that a significant reduction in antibiotic consumption may be achieved by procalcitonin-guided algorithms without sacrificing the outcome of patients with severe infection. SUMMARY In this article, we focus on procalcitonin and its potential role in differentiating cancer and infection-induced inflammation. Using this strategy may significantly reduce the usage of empirical broad-spectrum antibiotics and result in earlier discharge of patients.
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56
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Lancellotti P, Nchimi A, Delierneux C, Hego A, Gosset C, Gothot A, Jean-Flory Tshibanda L, Oury C. Biological Effects of Cardiac Magnetic Resonance on Human Blood Cells. Circ Cardiovasc Imaging 2015; 8:e003697. [PMID: 26338876 DOI: 10.1161/circimaging.115.003697] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cardiac magnetic resonance (CMR) is increasingly used for the diagnosis and management of cardiac diseases. Recent studies have reported immediate post-CMR DNA double-strand breaks in T lymphocytes. We sought to evaluate CMR-induced DNA damage in lymphocytes, alterations of blood cells, and their temporal persistence. METHODS AND RESULTS In 20 prospectively enrolled healthy men (31.4±7.9 years), blood was drawn before and after (1-2 hours, 2 days, 1 month, and 1 year) unenhanced 1.5T CMR. Blood cell counts, cell death, and activation status of lymphocytes, monocytes, neutrophils, and platelets were evaluated. The first 2-hour post-CMR were characterized by a small increase of lymphocyte B and neutrophil counts and a transient drop of total lymphocytes because of a decrease in natural killer cells. Among blood cells, only neutrophils and monocytes displayed slight and transient activation. DNA double-strand breaks in lymphocytes were quantified through flow cytometric analysis of H2AX phosphorylation (γ-H2AX). γ-H2AX intensity in T lymphocytes did not change early after CMR but increased significantly at day 2 ≤1 month before returning to baseline levels of 1-year post-CMR. CONCLUSIONS Unenhanced CMR is associated with minor but significant immediate blood cell alterations or activations figuring inflammatory response, as well as DNA damage in T lymphocytes observed from day 2 until the first month but disappearing at 1-year follow-up. Although further studies are required to definitely state whether CMR can be used safely, our findings already call for caution when it comes to repeat this examination within a month.
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Affiliation(s)
- Patrizio Lancellotti
- From the Department of Cardiology and Radiology, GIGA-Cardiovascular Sciences (P.L., A.N., C.D., A.H., A.G., L.J.-F.T., C.O.) and Hematology Department, University Hospital Sart Tilman (C.G., A.G.), University of Liège, Liège, Belgium; and Gruppo Villa Maria Care and Research, E.S. Health Science Foundation, Lugo (RA), Italy (P.L.).
| | - Alain Nchimi
- From the Department of Cardiology and Radiology, GIGA-Cardiovascular Sciences (P.L., A.N., C.D., A.H., A.G., L.J.-F.T., C.O.) and Hematology Department, University Hospital Sart Tilman (C.G., A.G.), University of Liège, Liège, Belgium; and Gruppo Villa Maria Care and Research, E.S. Health Science Foundation, Lugo (RA), Italy (P.L.)
| | - Céline Delierneux
- From the Department of Cardiology and Radiology, GIGA-Cardiovascular Sciences (P.L., A.N., C.D., A.H., A.G., L.J.-F.T., C.O.) and Hematology Department, University Hospital Sart Tilman (C.G., A.G.), University of Liège, Liège, Belgium; and Gruppo Villa Maria Care and Research, E.S. Health Science Foundation, Lugo (RA), Italy (P.L.)
| | - Alexandre Hego
- From the Department of Cardiology and Radiology, GIGA-Cardiovascular Sciences (P.L., A.N., C.D., A.H., A.G., L.J.-F.T., C.O.) and Hematology Department, University Hospital Sart Tilman (C.G., A.G.), University of Liège, Liège, Belgium; and Gruppo Villa Maria Care and Research, E.S. Health Science Foundation, Lugo (RA), Italy (P.L.)
| | - Christian Gosset
- From the Department of Cardiology and Radiology, GIGA-Cardiovascular Sciences (P.L., A.N., C.D., A.H., A.G., L.J.-F.T., C.O.) and Hematology Department, University Hospital Sart Tilman (C.G., A.G.), University of Liège, Liège, Belgium; and Gruppo Villa Maria Care and Research, E.S. Health Science Foundation, Lugo (RA), Italy (P.L.)
| | - André Gothot
- From the Department of Cardiology and Radiology, GIGA-Cardiovascular Sciences (P.L., A.N., C.D., A.H., A.G., L.J.-F.T., C.O.) and Hematology Department, University Hospital Sart Tilman (C.G., A.G.), University of Liège, Liège, Belgium; and Gruppo Villa Maria Care and Research, E.S. Health Science Foundation, Lugo (RA), Italy (P.L.)
| | - Luaba Jean-Flory Tshibanda
- From the Department of Cardiology and Radiology, GIGA-Cardiovascular Sciences (P.L., A.N., C.D., A.H., A.G., L.J.-F.T., C.O.) and Hematology Department, University Hospital Sart Tilman (C.G., A.G.), University of Liège, Liège, Belgium; and Gruppo Villa Maria Care and Research, E.S. Health Science Foundation, Lugo (RA), Italy (P.L.)
| | - Cécile Oury
- From the Department of Cardiology and Radiology, GIGA-Cardiovascular Sciences (P.L., A.N., C.D., A.H., A.G., L.J.-F.T., C.O.) and Hematology Department, University Hospital Sart Tilman (C.G., A.G.), University of Liège, Liège, Belgium; and Gruppo Villa Maria Care and Research, E.S. Health Science Foundation, Lugo (RA), Italy (P.L.)
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DNA damage-induced metaphase I arrest is mediated by the spindle assembly checkpoint and maternal age. Nat Commun 2015; 6:8706. [PMID: 26522734 PMCID: PMC4667640 DOI: 10.1038/ncomms9706] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 09/22/2015] [Indexed: 12/21/2022] Open
Abstract
In mammalian oocytes DNA damage can cause chromosomal abnormalities that potentially lead to infertility and developmental disorders. However, there is little known about the response of oocytes to DNA damage. Here we find that oocytes with DNA damage arrest at metaphase of the first meiosis (MI). The MI arrest is induced by the spindle assembly checkpoint (SAC) because inhibiting the SAC overrides the DNA damage-induced MI arrest. Furthermore, this MI checkpoint is compromised in oocytes from aged mice. These data lead us to propose that the SAC is a major gatekeeper preventing the progression of oocytes harbouring DNA damage. The SAC therefore acts to integrate protection against both aneuploidy and DNA damage by preventing production of abnormal mature oocytes and subsequent embryos. Finally, we suggest escaping this DNA damage checkpoint in maternal ageing may be one of the causes of increased chromosome anomalies in oocytes and embryos from older mothers.
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58
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Recruitment of RAG1 and RAG2 to Chromatinized DNA during V(D)J Recombination. Mol Cell Biol 2015; 35:3701-13. [PMID: 26303526 DOI: 10.1128/mcb.00219-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/09/2015] [Indexed: 11/20/2022] Open
Abstract
V(D)J recombination is initiated by the binding of the RAG1 and RAG2 proteins to recombination signal sequences (RSSs) that consist of conserved heptamer and nonamer sequences separated by a spacer of either 12 or 23 bp. Here, we used RAG-inducible pro-B v-Abl cell lines in conjunction with chromatin immunoprecipitation to better understand the protein and RSS requirements for RAG recruitment to chromatin. Using a catalytic mutant form of RAG1 to prevent recombination, we did not observe cooperation between RAG1 and RAG2 in their recruitment to endogenous Jκ gene segments over a 48-h time course. Using retroviral recombination substrates, we found that RAG1 was recruited inefficiently to substrates lacking an RSS or containing a single RSS, better to substrates with two 12-bp RSSs (12RSSs) or two 23-bp RSSs (23RSSs), and more efficiently to a substrate with a 12/23RSS pair. RSS mutagenesis demonstrated a major role for the nonamer element in RAG1 binding, and correspondingly, a cryptic RSS consisting of a repeat of CA dinucleotides, which poorly re-creates the nonamer, was ineffective in recruiting RAG1. Our findings suggest that 12RSS-23RSS cooperation (the "12/23 rule") is important not only for regulating RAG-mediated DNA cleavage but also for the efficiency of RAG recruitment to chromatin.
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59
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Karo JM, Sun JC. Novel molecular mechanism for generating NK-cell fitness and memory. Eur J Immunol 2015; 45:1906-15. [PMID: 26018782 DOI: 10.1002/eji.201445339] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/21/2015] [Accepted: 05/27/2015] [Indexed: 12/28/2022]
Abstract
The mammalian immune system has been traditionally subdivided into two compartments known as the innate and the adaptive. T cells and B cells, which rearrange their antigen-receptor genes using the RAG recombinase, comprise the adaptive arm of immunity. Meanwhile, every other white blood cell has been grouped together under the broad umbrella of innate immunity, including NK cells. NK cells are considered innate lymphocytes because of their rapid responses to stressed cells and their ability to develop without receptor gene rearrangement (i.e. in RAG-deficient mice). However, new findings implicate a critical function for RAG proteins during NK-cell ontogeny, and suggest a novel mechanism by which controlled DNA breaks during NK-cell development dictate the fitness, function, and longevity of these cells. This review highlights recent work describing how DNA break events can impact cellular differentiation and fitness in a variety of cell types and settings.
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Affiliation(s)
- Jenny M Karo
- Immunology Program and Gerstner Sloan Kettering Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Joseph C Sun
- Immunology Program and Gerstner Sloan Kettering Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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60
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Karo JM, Schatz DG, Sun JC. The RAG recombinase dictates functional heterogeneity and cellular fitness in natural killer cells. Cell 2015; 159:94-107. [PMID: 25259923 DOI: 10.1016/j.cell.2014.08.026] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 05/22/2014] [Accepted: 08/05/2014] [Indexed: 01/30/2023]
Abstract
The emergence of recombination-activating genes (RAGs) in jawed vertebrates endowed adaptive immune cells with the ability to assemble a diverse set of antigen receptor genes. In contrast, innate lymphocytes, such as natural killer (NK) cells, are not believed to require RAGs. Here, we report that NK cells unable to express RAGs or RAG endonuclease activity during ontogeny exhibit a cell-intrinsic hyperresponsiveness but a diminished capacity to survive following virus-driven proliferation, a reduced expression of DNA damage response mediators, and defects in the repair of DNA breaks. Evidence for this novel function of RAG has also been observed in T cells and innate lymphoid cells (ILCs), revealing an unexpected role for RAG proteins beyond V(D)J recombination. We propose that DNA cleavage events mediated by RAG endow developing adaptive and innate lymphocytes with a cellular "fitness" that safeguards their persistence later in life during episodes of rapid proliferation or cellular stress.
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Affiliation(s)
- Jenny M Karo
- Immunology Program and Gerstner Sloan Kettering Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - David G Schatz
- Department of Immunobiology and the Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Joseph C Sun
- Immunology Program and Gerstner Sloan Kettering Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
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Abstract
DNA double-strand breaks (DSBs) in cells can undergo nucleolytic degradation to generate long 3' single-stranded DNA tails. This process is termed DNA end resection, and its occurrence effectively commits to break repair via homologous recombination, which entails the acquisition of genetic information from an intact, homologous donor DNA sequence. Recent advances, prompted by the identification of the nucleases that catalyze resection, have revealed intricate layers of functional redundancy, interconnectedness, and regulation. Here, we review the current state of the field with an emphasis on the major questions that remain to be answered. Topics addressed will include how resection initiates via the introduction of an endonucleolytic incision close to the break end, the molecular mechanism of the conserved MRE11 complex in conjunction with Sae2/CtIP within such a model, the role of BRCA1 and 53BP1 in regulating resection initiation in mammalian cells, the influence of chromatin in the resection process, and potential roles of novel factors.
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Affiliation(s)
- James M Daley
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - Hengyao Niu
- Molecular and Cellular Biochemistry Department, Indiana University, Bloomington, IN 47405, USA
| | - Adam S Miller
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Patrick Sung
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
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62
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γ-H2AX induced by linear alkylbenzene sulfonates is due to deoxyribonuclease-1 translocation to the nucleus via actin disruption. Mutat Res 2015; 777:33-42. [PMID: 25938903 DOI: 10.1016/j.mrfmmm.2015.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 04/02/2015] [Accepted: 04/07/2015] [Indexed: 12/25/2022]
Abstract
Phosphorylation of histone H2AX (γ-H2AX) occurs following formation of DNA double strand breaks (DSBs). Other types of DNA damage also generate DSBs through DNA replication and repair, leading to the production of γ-H2AX. In the present study, we demonstrated that linear alkylbenzene sulfonates (LAS), the most widely used and non-genotoxic anionic surfactants, could generate γ-H2AX via a novel pathway. Breast adenocarcinoma MCF-7 cells were treated with five kinds of LAS with alkyl chains ranging from 10 to 14 carbon units (C10-C14LAS). The generation of DSBs and subsequent production of γ-H2AX increased in a manner that depended on the number of carbon units in LAS. γ-H2AX could also be generated with non-cytotoxic doses of LAS and was independent of the cell cycle, indicating the non-apoptotic and DNA replication-independent formation of DSBs. The generation of γ-H2AX could be attenuated by EGTA and ZnCl2, deoxyribonuclease-1 (DNase I) inhibitors, as well as by the knockdown of DNase I. LAS weakened the interaction between DNase I and actin, and the enhanced release of DNase I was dependent on the number of carbon units in LAS. DNase I released by the LAS treatment translocated to the nucleus, in which DNase I attacked DNA and generated γ-H2AX. These results suggested that the LAS-induced generation of γ-H2AX could be attributed to the translocation of DNase I to the nucleus through the disruption of actin, and not to LAS-induced DNA damage.
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Rosin N, Elcioglu NH, Beleggia F, Isgüven P, Altmüller J, Thiele H, Steindl K, Joset P, Rauch A, Nürnberg P, Wollnik B, Yigit G. Mutations in XRCC4 cause primary microcephaly, short stature and increased genomic instability. Hum Mol Genet 2015; 24:3708-17. [PMID: 25839420 DOI: 10.1093/hmg/ddv115] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 03/30/2015] [Indexed: 01/07/2023] Open
Abstract
DNA double-strand breaks (DSBs) are highly toxic lesions, which, if not properly repaired, can give rise to genomic instability. Non-homologous end-joining (NHEJ), a well-orchestrated, multistep process involving numerous proteins essential for cell viability, represents one major pathway to repair DSBs in mammalian cells, and mutations in different NHEJ components have been described in microcephalic syndromes associated, e.g. with short stature, facial dysmorphism and immune dysfunction. By using whole-exome sequencing, we now identified in three affected brothers of a consanguineous Turkish family a homozygous mutation, c.482G>A, in the XRCC4 gene encoding a crucial component of the NHEJ pathway. Moreover, we found one additional patient of Swiss origin carrying the compound heterozygous mutations c.25delG (p.His9Thrfs*8) and c.823C>T (p.Arg275*) in XRCC4. The clinical phenotype presented in these patients was characterized by severe microcephaly, facial dysmorphism and short stature, but they did not show a recognizable immunological phenotype. We showed that the XRCC4 c.482G>A mutation, which affects the last nucleotide of exon 4, induces defective splicing of XRCC4 pre-mRNA mainly resulting in premature protein truncation and most likely loss of XRCC4 function. Moreover, we observed on cellular level that XRCC4 deficiency leads to hypersensitivity to DSB-inducing agents and defective DSB repair, which results in increased cell death after exposure to genotoxic agents. Taken together, our data provide evidence that autosomal recessive mutations in XRCC4 induce increased genomic instability and cause a NHEJ-related syndrome defined by facial dysmorphism, primary microcephaly and short stature.
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Affiliation(s)
- Nadine Rosin
- Institute of Human Genetics, Center for Molecular Medicine Cologne (CMMC), Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and
| | - Nursel H Elcioglu
- Department of Pediatric Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Filippo Beleggia
- Institute of Human Genetics, Center for Molecular Medicine Cologne (CMMC), Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and
| | - Pinar Isgüven
- Department of Pediatric Endocrinology, Sakarya University Medical Faculty, Sakarya, Turkey and
| | - Janine Altmüller
- Institute of Human Genetics, Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Katharina Steindl
- Institute of Medical Genetics, University of Zurich, Zurich-Schlieren, Switzerland
| | - Pascal Joset
- Institute of Medical Genetics, University of Zurich, Zurich-Schlieren, Switzerland
| | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, Zurich-Schlieren, Switzerland
| | - Peter Nürnberg
- Center for Molecular Medicine Cologne (CMMC), Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, Center for Molecular Medicine Cologne (CMMC), Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and
| | - Gökhan Yigit
- Institute of Human Genetics, Center for Molecular Medicine Cologne (CMMC), Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and
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Lu Y, Gao J, Lu Y. Down-expression pattern of Ku70 and p53 coexisted in colorectal cancer. Med Oncol 2015; 32:98. [PMID: 25731619 DOI: 10.1007/s12032-015-0519-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/13/2015] [Indexed: 11/24/2022]
Abstract
To address the relationship of altered expression of double-strand break repair proteins Ku70 and p53 in clinical colorectal cancer (CRC), we examined the expression pattern of Ku70 and p53 by using fluorescent immunohistochemistry and real-time PCR assays in CRC and pericancerous samples from 152 Chinese patients. The results showed that down-expression pattern of both Ku70 and p53 coexisted in the CRC samples with significant correlating rate (R (2) = 0.9103; P < 0.001), and the down-expression of Ku70 and p53 was significantly associated with the advanced tumor node metastasis stage (Ku70: HR 3.453 in recurrence and 4.182 in survival, P < 0.001; P53: HR 3.114 in recurrence and 4.113 in survival, P < 0.001). The down-regulated Ku70 and p53 were associated with poor disease-free survival. Loss of Ku70 and p53 expression might serve as a biomarker of poor prognosis in CRC patients.
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Affiliation(s)
- Yuanfang Lu
- Department of Toxicology, School of Public Health, Guilin Medical University, North Huancheng 2nd Road, Guilin, 541004, Guangxi, China
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Brečević L, Rinčić M, Krsnik Ž, Sedmak G, Hamid AB, Kosyakova N, Galić I, Liehr T, Borovečki F. Association of new deletion/duplication region at chromosome 1p21 with intellectual disability, severe speech deficit and autism spectrum disorder-like behavior: an all-in approach to solving the DPYD enigma. Transl Neurosci 2015; 6:59-86. [PMID: 28123791 PMCID: PMC4936614 DOI: 10.1515/tnsci-2015-0007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 12/29/2014] [Indexed: 12/14/2022] Open
Abstract
We describe an as yet unreported neocentric small supernumerary marker chromosome (sSMC) derived from chromosome 1p21.3p21.2. It was present in 80% of the lymphocytes in a male patient with intellectual disability, severe speech deficit, mild dysmorphic features, and hyperactivity with elements of autism spectrum disorder (ASD). Several important neurodevelopmental genes are affected by the 3.56 Mb copy number gain of 1p21.3p21.2, which may be considered reciprocal in gene content to the recently recognized 1p21.3 microdeletion syndrome. Both 1p21.3 deletions and the presented duplication display overlapping symptoms, fitting the same disorder category. Contribution of coding and non-coding genes to the phenotype is discussed in the light of cellular and intercellular homeostasis disequilibrium. In line with this the presented 1p21.3p21.2 copy number gain correlated to 1p21.3 microdeletion syndrome verifies the hypothesis of a cumulative effect of the number of deregulated genes - homeostasis disequilibrium leading to overlapping phenotypes between microdeletion and microduplication syndromes. Although miR-137 appears to be the major player in the 1p21.3p21.2 region, deregulation of the DPYD (dihydropyrimidine dehydrogenase) gene may potentially affect neighboring genes underlying the overlapping symptoms present in both the copy number loss and copy number gain of 1p21. Namely, the all-in approach revealed that DPYD is a complex gene whose expression is epigenetically regulated by long non-coding RNAs (lncRNAs) within the locus. Furthermore, the long interspersed nuclear element-1 (LINE-1) L1MC1 transposon inserted in DPYD intronic transcript 1 (DPYD-IT1) lncRNA with its parasites, TcMAR-Tigger5b and pair of Alu repeats appears to be the “weakest link” within the DPYD gene liable to break. Identification of the precise mechanism through which DPYD is epigenetically regulated, and underlying reasons why exactly the break (FRA1E) happens, will consequently pave the way toward preventing severe toxicity to the antineoplastic drug 5-fluorouracil (5-FU) and development of the causative therapy for the dihydropyrimidine dehydrogenase deficiency.
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Affiliation(s)
- Lukrecija Brečević
- Croatian Institute for Brain Research, University of Zagreb Medical School, Šalata 12, 10000 Zagreb, Croatia
- Department for Functional Genomics, Center for Translational and Clinical Research, University of Zagreb Medical School, University Hospital Center Zagreb, Šalata 2, 10000 Zagreb, Croatia
- E-mail: ;
| | - Martina Rinčić
- Croatian Institute for Brain Research, University of Zagreb Medical School, Šalata 12, 10000 Zagreb, Croatia
- Department for Functional Genomics, Center for Translational and Clinical Research, University of Zagreb Medical School, University Hospital Center Zagreb, Šalata 2, 10000 Zagreb, Croatia
- Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, 07743 Jena, Germany
| | - Željka Krsnik
- Croatian Institute for Brain Research, University of Zagreb Medical School, Šalata 12, 10000 Zagreb, Croatia
| | - Goran Sedmak
- Croatian Institute for Brain Research, University of Zagreb Medical School, Šalata 12, 10000 Zagreb, Croatia
| | - Ahmed B. Hamid
- Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, 07743 Jena, Germany
| | - Nadezda Kosyakova
- Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, 07743 Jena, Germany
| | - Ivan Galić
- Center for Rehabilitation Stančić, Stančić bb, 10370 Stančić, Croatia
| | - Thomas Liehr
- Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Kollegiengasse 10, 07743 Jena, Germany
| | - Fran Borovečki
- Department for Functional Genomics, Center for Translational and Clinical Research, University of Zagreb Medical School, University Hospital Center Zagreb, Šalata 2, 10000 Zagreb, Croatia
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Rodgers W, Byrum JN, Sapkota H, Rahman NS, Cail RC, Zhao S, Schatz DG, Rodgers KK. Spatio-temporal regulation of RAG2 following genotoxic stress. DNA Repair (Amst) 2015; 27:19-27. [PMID: 25625798 PMCID: PMC4336829 DOI: 10.1016/j.dnarep.2014.12.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 12/23/2014] [Accepted: 12/31/2014] [Indexed: 11/30/2022]
Abstract
V(D)J recombination of lymphocyte antigen receptor genes occurs via the formation of DNA double strand breaks (DSBs) through the activity of RAG1 and RAG2. The co-existence of RAG-independent DNA DSBs generated by genotoxic stressors potentially increases the risk of incorrect repair and chromosomal abnormalities. However, it is not known whether cellular responses to DSBs by genotoxic stressors affect the RAG complex. Using cellular imaging and subcellular fractionation approaches, we show that formation of DSBs by treating cells with DNA damaging agents causes export of nuclear RAG2. Within the cytoplasm, RAG2 exhibited substantial enrichment at the centrosome. Further, RAG2 export was sensitive to inhibition of ATM, and was reversed following DNA repair. The core region of RAG2 was sufficient for export, but not centrosome targeting, and RAG2 export was blocked by mutation of Thr(490). In summary, DNA damage triggers relocalization of RAG2 from the nucleus to centrosomes, suggesting a novel mechanism for modulating cellular responses to DSBs in developing lymphocytes.
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Affiliation(s)
- William Rodgers
- Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Microbiology and Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jennifer N Byrum
- Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Hem Sapkota
- Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Negar S Rahman
- Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Robert C Cail
- Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Shuying Zhao
- Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - David G Schatz
- Department of Immunobiology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, USA
| | - Karla K Rodgers
- Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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DNA damage response – A double-edged sword in cancer prevention and cancer therapy. Cancer Lett 2015; 358:8-16. [DOI: 10.1016/j.canlet.2014.12.038] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 12/15/2014] [Accepted: 12/15/2014] [Indexed: 12/27/2022]
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Kao S, Tseng C, Wan C, Su Y, Hsieh C, Pi H, Hsu H. Aging and insulin signaling differentially control normal and tumorous germline stem cells. Aging Cell 2015; 14:25-34. [PMID: 25470527 PMCID: PMC4326914 DOI: 10.1111/acel.12288] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2014] [Indexed: 01/01/2023] Open
Abstract
Aging influences stem cells, but the processes involved remain unclear. Insulin signaling, which controls cellular nutrient sensing and organismal aging, regulates the G2 phase of Drosophila female germ line stem cell (GSC) division cycle in response to diet; furthermore, this signaling pathway is attenuated with age. The role of insulin signaling in GSCs as organisms age, however, is also unclear. Here, we report that aging results in the accumulation of tumorous GSCs, accompanied by a decline in GSC number and proliferation rate. Intriguingly, GSC loss with age is hastened by either accelerating (through eliminating expression of Myt1, a cell cycle inhibitory regulator) or delaying (through mutation of insulin receptor (dinR) GSC division, implying that disrupted cell cycle progression and insulin signaling contribute to age-dependent GSC loss. As flies age, DNA damage accumulates in GSCs, and the S phase of the GSC cell cycle is prolonged. In addition, GSC tumors (which escape the normal stem cell regulatory microenvironment, known as the niche) still respond to aging in a similar manner to normal GSCs, suggesting that niche signals are not required for GSCs to sense or respond to aging. Finally, we show that GSCs from mated and unmated females behave similarly, indicating that female GSC–male communication does not affect GSCs with age. Our results indicate the differential effects of aging and diet mediated by insulin signaling on the stem cell division cycle, highlight the complexity of the regulation of stem cell aging, and describe a link between ovarian cancer and aging.
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Affiliation(s)
- Shih‐Han Kao
- Institute of Cellular and Organismic Biology Academia Sinica Taipei 11529 Taiwan
| | - Chen‐Yuan Tseng
- Institute of Cellular and Organismic Biology Academia Sinica Taipei 11529 Taiwan
- Graduate Institute of Life Sciences National Defense Medical Center Taipei 11490 Taiwan
| | - Chih‐Ling Wan
- Institute of Cellular and Organismic Biology Academia Sinica Taipei 11529 Taiwan
| | - Yu‐Han Su
- Institute of Cellular and Organismic Biology Academia Sinica Taipei 11529 Taiwan
| | - Chang‐Che Hsieh
- Department of Biomedical Science College of Medicine Chang Gung University Tao‐Yuan 333 Taiwan
| | - Haiwei Pi
- Department of Biomedical Science College of Medicine Chang Gung University Tao‐Yuan 333 Taiwan
| | - Hwei‐Jan Hsu
- Institute of Cellular and Organismic Biology Academia Sinica Taipei 11529 Taiwan
- Graduate Institute of Life Sciences National Defense Medical Center Taipei 11490 Taiwan
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Borgie M, Ledoux F, Verdin A, Cazier F, Greige H, Shirali P, Courcot D, Dagher Z. Genotoxic and epigenotoxic effects of fine particulate matter from rural and urban sites in Lebanon on human bronchial epithelial cells. ENVIRONMENTAL RESEARCH 2015; 136:352-362. [PMID: 25460656 DOI: 10.1016/j.envres.2014.10.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 09/21/2014] [Accepted: 10/14/2014] [Indexed: 06/04/2023]
Abstract
Assessment of air pollution by particulate matter (PM) is strongly required in Lebanon in the absence of an air quality law including updated air quality standards. Using two different PM2.5-0.3 samples collected at an urban and a rural site, we examined genotoxic/epigenotoxic effects of PM exposure within a human bronchial epithelial cell line (BEAS-2B). Inorganic and organic contents evidence the major contribution of traffic and generating sets in the PM2.5-0.3 composition. Urban PM2.5-0.3 sample increased the phosphorylation of H2AX, the telomerase activity and the miR-21 up-regulation in BEAS-2B cells in a dose-dependent manner. Furthermore, urban PM2.5-0.3 induced a significant increase in CYP1A1, CYP1B1 and AhRR genes expression. The variable concentrations of transition metals and organic compounds detected in the collected PM2.5-0.3 samples might be the active agents leading to a cumulative DNA damage, critical for carcinogenesis.
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Affiliation(s)
- Mireille Borgie
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel, Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, 59140 Dunkerque, France; Groupe de Recherche Molécules Bioactives, Ecole Doctorale des Sciences et Technologies, Université Libanaise, Liban; Université Lille Nord de France, Lille, France
| | - Frédéric Ledoux
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel, Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, 59140 Dunkerque, France; Université Lille Nord de France, Lille, France
| | - Anthony Verdin
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel, Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, 59140 Dunkerque, France; Université Lille Nord de France, Lille, France
| | - Fabrice Cazier
- Centre Commun de Mesures, Maison de la Recherche en Environnement Industriel 1, Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, 59140 Dunkerque, France; Université Lille Nord de France, Lille, France
| | - Hélène Greige
- Groupe de Recherche Molécules Bioactives, Ecole Doctorale des Sciences et Technologies, Université Libanaise, Liban; Département de Chimie et de Biochimie, Faculté des Sciences, Université Libanaise, Liban
| | - Pirouz Shirali
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel, Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, 59140 Dunkerque, France; Université Lille Nord de France, Lille, France
| | - Dominique Courcot
- Unité de Chimie Environnementale et Interactions sur le Vivant (UCEIV), EA 4492, Maison de la Recherche en Environnement Industriel, Université du Littoral Côte d'Opale, 145 Avenue Maurice Schumann, 59140 Dunkerque, France; Université Lille Nord de France, Lille, France.
| | - Zeina Dagher
- Groupe de Recherche Molécules Bioactives, Ecole Doctorale des Sciences et Technologies, Université Libanaise, Liban; Département de Biologie, Faculté des Sciences, Université Libanaise, Liban
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Gustafsson AS, Abramenkovs A, Stenerlöw B. Suppression of DNA-dependent protein kinase sensitize cells to radiation without affecting DSB repair. Mutat Res 2014; 769:1-10. [PMID: 25771720 DOI: 10.1016/j.mrfmmm.2014.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 06/04/2014] [Accepted: 06/16/2014] [Indexed: 06/04/2023]
Abstract
Efficient and correct repair of DNA double-strand break (DSB) is critical for cell survival. Defects in the DNA repair may lead to cell death, genomic instability and development of cancer. The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is an essential component of the non-homologous end joining (NHEJ) which is the major DSB repair pathway in mammalian cells. In the present study, by using siRNA against DNA-PKcs in four human cell lines, we examined how low levels of DNA-PKcs affected cellular response to ionizing radiation. Decrease of DNA-PKcs levels by 80-95%, induced by siRNA treatment, lead to extreme radiosensitivity, similar to that seen in cells completely lacking DNA-PKcs and low levels of DNA-PKcs promoted cell accumulation in G2/M phase after irradiation and blocked progression of mitosis. Surprisingly, low levels of DNA-PKcs did not affect the repair capacity and the removal of 53BP1 or γ-H2AX foci and rejoining of DSB appeared normal. This was in strong contrast to cells completely lacking DNA-PKcs and cells treated with the DNA-PKcs inhibitor NU7441, in which DSB repair were severely compromised. This suggests that there are different mechanisms by which loss of DNA-PKcs functions can sensitize cells to ionizing radiation. Further, foci of phosphorylated DNA-PKcs (T2609 and S2056) co-localized with DSB and this was independent of the amount of DNA-PKcs but foci of DNA-PKcs was only seen in siRNA-treated cells. Our study emphasizes on the critical role of DNA-PKcs for maintaining survival after radiation exposure which is uncoupled from its essential function in DSB repair. This could have implications for the development of therapeutic strategies aiming to radiosensitize tumors by affecting the DNA-PKcs function.
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Affiliation(s)
- Ann-Sofie Gustafsson
- Section of Biomedical Radiation Sciences, Department of Radiology, Oncology and Radiation Science, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds Väg 20, SE-751 85 Uppsala, Sweden.
| | - Andris Abramenkovs
- Section of Biomedical Radiation Sciences, Department of Radiology, Oncology and Radiation Science, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds Väg 20, SE-751 85 Uppsala, Sweden
| | - Bo Stenerlöw
- Section of Biomedical Radiation Sciences, Department of Radiology, Oncology and Radiation Science, Rudbeck Laboratory, Uppsala University, Dag Hammarskjölds Väg 20, SE-751 85 Uppsala, Sweden
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Lu Y, Gao J, Lu Y. Downregulated Ku70 and ATM associated to poor prognosis in colorectal cancer among Chinese patients. Onco Targets Ther 2014; 7:1955-61. [PMID: 25368522 PMCID: PMC4216044 DOI: 10.2147/ott.s67814] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background Double-strand DNA breaks (DSBs) are a key factor in carcinogenesis. The necessary repair of DSBs is pivotal in maintaining normal cell division. To address the relationship between altered expression of DSB repair of proteins Ku70 and ataxia-telangiectasia mutated (ATM) in colorectal cancer (CRC), we examined the expression levels and patterns of Ku70 and ATM in CRC samples. Methods Expression and coexpression of Ku70 and ATM were investigated by using real-time quantitative polymerase chain reaction assays and confirmed further with fluorescent immunohistochemistry in CRC and pericancerous samples from 112 Chinese patients. Results Downexpression patterns for both Ku70 and ATM were found in the CRC samples and were significantly associated with advanced tumor node metastasis stage and decreased 5-year overall survival rate. Conclusion Downregulated Ku70 and ATM were associated with poor disease-free survival. Loss of Ku70 and ATM expression might act as a biomarker to predict poor prognosis in patients with CRC.
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Affiliation(s)
- Yuanfang Lu
- Department of Toxicology, School of Public Health, Guilin Medical University, Guangxi, People's Republic of China ; Department of Clinical Research Center, Affiliated 2nd Hospital of Nanjing Medical University, Nanjing, People's Republic of China
| | - Jingyan Gao
- Department of Toxicology, School of Public Health, Guilin Medical University, Guangxi, People's Republic of China ; Department of Human Anatomy and Histo-Embryology, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Yuanming Lu
- Department of Toxicology, School of Public Health, Guilin Medical University, Guangxi, People's Republic of China
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Alternative lengthening of telomeres: recurrent cytogenetic aberrations and chromosome stability under extreme telomere dysfunction. Neoplasia 2014; 15:1301-13. [PMID: 24339742 DOI: 10.1593/neo.131574] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/17/2013] [Accepted: 10/21/2013] [Indexed: 12/23/2022] Open
Abstract
Human tumors using the alternative lengthening of telomeres (ALT) exert high rates of telomere dysfunction. Numerical chromosomal aberrations are very frequent, and structural rearrangements are widely scattered among the genome. This challenging context allows the study of telomere dysfunction-driven chromosomal instability in neoplasia (CIN) in a massive scale. We used molecular cytogenetics to achieve detailed karyotyping in 10 human ALT neoplastic cell lines. We identified 518 clonal recombinant chromosomes affected by 649 structural rearrangements. While all human chromosomes were involved in random or clonal, terminal, or pericentromeric rearrangements and were capable to undergo telomere healing at broken ends, a differential recombinatorial propensity of specific genomic regions was noted. We show that ALT cells undergo epigenetic modifications rendering polycentric chromosomes functionally monocentric, and because of increased terminal recombinogenicity, they generate clonal recombinant chromosomes with interstitial telomeric repeats. Losses of chromosomes 13, X, and 22, gains of 2, 3, 5, and 20, and translocation/deletion events involving several common chromosomal fragile sites (CFSs) were recurrent. Long-term reconstitution of telomerase activity in ALT cells reduced significantly the rates of random ongoing telomeric and pericentromeric CIN. However, the contribution of CFS in overall CIN remained unaffected, suggesting that in ALT cells whole-genome replication stress is not suppressed by telomerase activation. Our results provide novel insights into ALT-driven CIN, unveiling in parallel specific genomic sites that may harbor genes critical for ALT cancerous cell growth.
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73
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Kines KJ, Sokolowski M, deHaro DL, Christian CM, Belancio VP. Potential for genomic instability associated with retrotranspositionally-incompetent L1 loci. Nucleic Acids Res 2014; 42:10488-502. [PMID: 25143528 PMCID: PMC4176336 DOI: 10.1093/nar/gku687] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Expression of the L1 retrotransposon can damage the genome through insertional mutagenesis and the generation of DNA double-strand breaks (DSBs). The majority of L1 loci in the human genome are 5'-truncated and therefore incapable of retrotransposition. While thousands of full-length L1 loci remain, most are retrotranspositionally-incompetent due to inactivating mutations. However, mutations leading to premature stop codons within the L1 ORF2 sequence may yield truncated proteins that retain a functional endonuclease domain. We demonstrate that some truncated ORF2 proteins cause varying levels of toxicity and DNA damage when chronically overexpressed in mammalian cells. Furthermore, transfection of some ORF2 constructs containing premature stop codons supported low levels of Alu retrotransposition, demonstrating the potential for select retrotranspositionally-incompetent L1 loci to generate genomic instability. This result suggests yet another plausible explanation for the relative success of Alu elements in populating the human genome. Our data suggest that a subset of retrotranspositionally-incompetent L1s, previously considered to be harmless to genomic integrity, may have the potential to cause chronic DNA damage by introducing DSBs and mobilizing Alu. These results imply that the number of known L1 loci in the human genome that potentially threaten its stability may not be limited to the retrotranspositionally active loci.
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Affiliation(s)
- Kristine J Kines
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Mark Sokolowski
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Dawn L deHaro
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Claiborne M Christian
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112, USA
| | - Victoria P Belancio
- Department of Structural and Cellular Biology, Tulane School of Medicine, Tulane Cancer Center, and Tulane Center for Aging, New Orleans, LA 70112, USA
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74
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Łakomiec K, Kumala S, Hancock R, Rzeszowska-Wolny J, Fujarewicz K. Modeling the repair of DNA strand breaks caused by γ-radiation in a minichromosome. Phys Biol 2014; 11:045003. [PMID: 25076006 DOI: 10.1088/1478-3975/11/4/045003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objective of the studies described here was the development of a mathematical model which would fit experimental data for the repair of single and double strand breaks induced in DNA in living cells by exposure to ionizing radiation, and which would allow to better understand the processes of DNA repair. DNA breaks are believed to play the major role in radiation-induced lethality and formation of chromosome deletions, and are therefore crucial to the response of cells to radiotherapy. In an initial model which we reported on the basis of data for the repair of Epstein-Barr minichromosomes in irradiated Raji cells, we assumed that DNA breaks are induced only at the moment of irradiation and are later removed by repair systems. This work gives a development of that mathematical model which fits the experimental results more precisely and suggests strongly that DNA breaks are generated not only by direct irradiation but also later, probably by systems engaged in repair of oxidative damage.
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Affiliation(s)
- K Łakomiec
- Institute of Automatic Control, Silesian University of Technology, Gliwice, Poland
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75
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Peng S, Huo X, Rezaei D, Zhang Q, Zhang X, Yu C, Asanuma K, Cheng E, Pham TH, Wang DH, Chen M, Souza RF, Spechler SJ. In Barrett's esophagus patients and Barrett's cell lines, ursodeoxycholic acid increases antioxidant expression and prevents DNA damage by bile acids. Am J Physiol Gastrointest Liver Physiol 2014; 307:G129-39. [PMID: 24852569 PMCID: PMC4101678 DOI: 10.1152/ajpgi.00085.2014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Hydrophobic bile acids like deoxycholic acid (DCA), which cause oxidative DNA damage and activate NF-κB in Barrett's metaplasia, might contribute to carcinogenesis in Barrett's esophagus. We have explored mechanisms whereby ursodeoxycholic acid (UDCA, a hydrophilic bile acid) protects against DCA-induced injury in vivo in patients and in vitro using nonneoplastic, telomerase-immortalized Barrett's cell lines. We took biopsies of Barrett's esophagus from 21 patients before and after esophageal perfusion with DCA (250 μM) at baseline and after 8 wk of oral UDCA treatment. DNA damage was assessed by phospho-H2AX expression, neutral CometAssay, and phospho-H2AX nuclear foci formation. Quantitative PCR was performed for antioxidants including catalase and GPX1. Nrf2, catalase, and GPX1 were knocked down with siRNAs. Reporter assays were performed using a plasmid construct containing antioxidant responsive element. In patients, baseline esophageal perfusion with DCA significantly increased phospho-H2AX and phospho-p65 in Barrett's metaplasia. Oral UDCA increased GPX1 and catalase levels in Barrett's metaplasia and prevented DCA perfusion from inducing DNA damage and NF-κB activation. In cells, DCA-induced DNA damage and NF-κB activation was prevented by 24-h pretreatment with UDCA, but not by mixing UDCA with DCA. UDCA activated Nrf2 signaling to increase GPX1 and catalase expression, and protective effects of UDCA pretreatment were blocked by siRNA knockdown of these antioxidants. UDCA increases expression of antioxidants that prevent toxic bile acids from causing DNA damage and NF-κB activation in Barrett's metaplasia. Elucidation of this molecular pathway for UDCA protection provides rationale for clinical trials on UDCA for chemoprevention in Barrett's esophagus.
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Affiliation(s)
- Sui Peng
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas; ,6Division of Gastroenterology and Hepatology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Xiaofang Huo
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Davood Rezaei
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,4Department of Research and Development, VA North Texas Heath Care System, Dallas, Texas;
| | - Qiuyang Zhang
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Xi Zhang
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Chunhua Yu
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Kiyotaka Asanuma
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Edaire Cheng
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,5Department of Pediatrics, Children's Medical Center and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Thai H. Pham
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,3Department of Surgery, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - David H. Wang
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Minhu Chen
- 6Division of Gastroenterology and Hepatology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Rhonda F. Souza
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
| | - Stuart Jon Spechler
- 1Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas, ,2Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, Texas;
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76
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Litvinov SV. Main repair pathways of double-strand breaks in the genomic DNA and interactions between them. CYTOL GENET+ 2014. [DOI: 10.3103/s0095452714030062] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Li D, Cao W. Role of intracellular calcium and NADPH oxidase NOX5-S in acid-induced DNA damage in Barrett's cells and Barrett's esophageal adenocarcinoma cells. Am J Physiol Gastrointest Liver Physiol 2014; 306:G863-72. [PMID: 24699332 PMCID: PMC4024726 DOI: 10.1152/ajpgi.00321.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mechanisms whereby acid reflux may accelerate the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA) are not fully understood. Acid and reactive oxygen species (ROS) have been reported to cause DNA damage in Barrett's cells. We have previously shown that NADPH oxidase NOX5-S is responsible for acid-induced H2O2 production in Barrett's cells and in EA cells. In this study we examined the role of intracellular calcium and NADPH oxidase NOX5-S in acid-induced DNA damage in a Barrett's EA cell line FLO and a Barrett's cell line CP-A. We found that pulsed acid treatment significantly increased tail moment in FLO and CP-A cells and histone H2AX phosphorylation in FLO cells. In addition, acid treatment significantly increased intracellular Ca(2+) in FLO cells, an increase that is blocked by Ca(2+)-free medium with EGTA and thapsigargin. Acid-induced increase in tail moment was significantly decreased by NADPH oxidase inhibitor diphenylene iodonium in FLO cells, and by blockade of intracellular Ca(2+) increase or knockdown of NOX5-S with NOX5 small-interfering RNA (siRNA) in FLO and CP-A cells. Acid-induced increase in histone H2AX phosphorylation was significantly decreased by NOX5 siRNA in FLO cells. Conversely, overexpression of NOX5-S significantly increased tail moment and histone H2AX phosphorylation in FLO cells. We conclude that pulsed acid treatment causes DNA damage via increase of intracellular calcium and activation of NOX5-S. It is possible that in BE acid reflux increases intracellular calcium, activates NOX5-S, and increases ROS production, which causes DNA damage, thereby contributing to the progression from BE to EA.
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Affiliation(s)
- Dan Li
- 1Department of Medicine, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, Rhode Island; and
| | - Weibiao Cao
- Department of Medicine, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, Rhode Island; and Department of Pathology, Rhode Island Hospital and Warren Alpert Medical School of Brown University, Providence, Rhode Island
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78
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Kim YZ. Altered histone modifications in gliomas. Brain Tumor Res Treat 2014; 2:7-21. [PMID: 24926467 PMCID: PMC4049557 DOI: 10.14791/btrt.2014.2.1.7] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 03/16/2014] [Accepted: 03/21/2014] [Indexed: 12/24/2022] Open
Abstract
Gliomas are the most frequently occurring primary brain tumors in adults. Although they exist in different malignant stages, including histologically benign forms and highly aggressive states, most gliomas are clinically challenging for neuro-oncologists because of their infiltrative growth patterns and inherent relapse tendency with increased malignancy. Once this disease reaches the glioblastoma multiforme stage, the prognosis of patients is dismal: median survival time is 15 months. Extensive genetic analyses of glial tumors have revealed a variety of deregulated genetic pathways involved in DNA repair, apoptosis, cell migration/adhesion, and cell cycle. Recently, it has become evident that epigenetic alterations may also be an important factor for glioma genesis. Of epigenetic marks, histone modification is a key mark that regulates gene expression and thus modulates a wide range of cellular processes. In this review, I discuss the neuro-oncological significance of altered histone modifications and modifiers in glioma patients while briefly overviewing the biological roles of histone modifications.
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Affiliation(s)
- Young Zoon Kim
- Division of Neuro-Oncology, Department of Neurosurgery, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea
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79
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Biomarkers of mercury exposure in the Amazon. BIOMED RESEARCH INTERNATIONAL 2014; 2014:867069. [PMID: 24895619 PMCID: PMC4020561 DOI: 10.1155/2014/867069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Accepted: 04/08/2014] [Indexed: 11/22/2022]
Abstract
Mercury exposure in the Amazon has been studied since the 1980s decade and the assessment of human mercury exposure in the Amazon is difficult given that the natural occurrence of this metal is high and the concentration of mercury in biological samples of this population exceeds the standardized value of normality established by WHO. Few studies have focused on the discovery of mercury biomarkers in the region's population. In this way, some studies have used genetics as well as immunological and cytogenetic tools in order to find a molecular biomarker for assessing the toxicological effect of mercury in the Amazonian population. Most of those studies focused attention on the relation between mercury exposure and autoimmunity and, because of that, they will be discussed in more detail. Here we introduce the general aspects involved with each biomarker that was studied in the region in order to contextualize the reader and add information about the Amazonian life style and health that may be considered for future studies. We hope that, in the future, the toxicological studies in this field use high technological tools, such as the next generation sequencing and proteomics skills, in order to comprehend basic questions regarding the metabolic route of mercury in populations that are under constant exposure, such as in the Amazon.
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80
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Impairment of cell cycle progression by sterigmatocystin in human pulmonary cells in vitro. Food Chem Toxicol 2014; 66:89-95. [DOI: 10.1016/j.fct.2014.01.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 01/11/2014] [Accepted: 01/14/2014] [Indexed: 01/11/2023]
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81
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Abstract
Telomere length is considered to be a risk factor in adults due to its proved association with cancer incidence and mortality. Since newborn present a wide interindividual variation in mean telomere length, it is relevant to demonstrate if these differences in length can act also as an early risk indicator. To answer this question, we have measured the mean telomere length of 74 samples of cord blood from newborns and studied its association with the basal genetic damage, measured as the frequency of binucleated cells carrying micronuclei. In addition, we have challenged the cells of a subgroup of individuals (N = 35) against mitomycin-C (MMC) to establish their sensitivity to induced genomic instability. Results indicate that newborn with shorter telomeres present significantly higher levels of genetic damage when compared to those with longer telomeres. In addition, the cellular response to MMC was also significantly higher among those samples from subjects with shorter telomeres. Independently of the causal mechanisms involved, our results show for the first time that telomere length at delivery influence both the basal and induced genetic damage of the individual. Impact Individuals born with shorter telomeres may be at increased risk, especially for those biological processes triggered by genomic instability as is the case of cancer and other age-related diseases.
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82
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Abstract
Barrett's esophagus, the condition in which metaplastic columnar epithelium that predisposes to cancer development replaces the squamous epithelium that normally lines the distal esophagus, is a complication of gastroesophageal reflux disease (GERD). Metaplasia is a potentially reversible condition, and partial regression of Barrett's metaplasia has been documented with effective medical or surgical therapy for GERD. The important issue for patient management is not whether antireflux treatment causes Barrett's esophagus to regress, but rather whether antireflux therapy prevents cancer in Barrett's esophagus. Proton pump inhibitors (PPIs) would be expected to prevent this cancer because they heal reflux esophagitis, reduce exposure to a potential carcinogen (acid), and might prevent acid-induced proliferation and cancer-promoting cytokine secretion by esophageal epithelial cells. Furthermore, observational studies have shown that PPI use is associated with a decreased incidence of neoplasia in Barrett's esophagus. In theory, successful antireflux surgery, which eliminates the reflux of both acid and bile, should be better for cancer prevention than medical therapy, which only decreases the reflux of acid. However, high-quality studies show no significant difference in cancer incidence between medically and surgically treated patients with GERD and Barrett's esophagus. Furthermore, for individual patients with nondysplastic Barrett's metaplasia, the cancer risk is so small and the number needed to treat for cancer prevention with surgery so large, that it does not matter whether or not surgery provides a tiny margin of extra protection against cancer beyond that provided by medical therapy. The cost and risks of the operation overwhelm any small, additional cancer protective benefit. Antireflux surgery is very effective at controlling the endoscopic signs and symptoms of GERD, but the operation should not be recommended to patients solely with the rationale that it protects against cancer better than medical therapy.
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Affiliation(s)
- Stuart Jon Spechler
- Department of Medicine, VA North Texas Healthcare System, and the University of Texas Southwestern Medical Center at Dallas, Dallas, Tex., USA
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83
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Nuclear Nox4-derived reactive oxygen species in myelodysplastic syndromes. BIOMED RESEARCH INTERNATIONAL 2014; 2014:456937. [PMID: 24719867 PMCID: PMC3955662 DOI: 10.1155/2014/456937] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/21/2014] [Indexed: 12/25/2022]
Abstract
A role for intracellular ROS production has been recently implicated in the pathogenesis and progression of a wide variety of neoplasias. ROS sources, such as NAD(P)H oxidase (Nox) complexes, are frequently activated in AML (acute myeloid leukemia) blasts and strongly contribute to their proliferation, survival, and drug resistance. Myelodysplastic syndromes (MDS) comprise a heterogeneous group of disorders characterized by ineffective hematopoiesis, with an increased propensity to develop AML. The molecular basis for MDS progression is unknown, but a key element in MDS disease progression is the genomic instability. NADPH oxidases are now recognized to have specific subcellular localizations, this targeting to specific compartments for localized ROS production. Local Nox-dependent ROS production in the nucleus may contribute to the regulation of redox-dependent cell growth, differentiation, senescence, DNA damage, and apoptosis. We observed that Nox1, 2, and 4 isoforms and p22phox and Rac1 subunits are expressed in MDS/AML cell lines and MDS samples, also in the nuclear fractions. Interestingly, Nox4 interacts with ERK and Akt1 within nuclear speckle domain, suggesting that Nox4 could be involved in regulating gene expression and splicing factor activity. These data contribute to the elucidation of the molecular mechanisms used by nuclear ROS to drive MDS evolution to AML.
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84
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Halper-Stromberg E, Steranka J, Burns KH, Sabunciyan S, Irizarry RA. Visualization and probability-based scoring of structural variants within repetitive sequences. ACTA ACUST UNITED AC 2014; 30:1514-21. [PMID: 24501098 PMCID: PMC4029030 DOI: 10.1093/bioinformatics/btu054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
MOTIVATION Repetitive sequences account for approximately half of the human genome. Accurately ascertaining sequences in these regions with next generation sequencers is challenging, and requires a different set of analytical techniques than for reads originating from unique sequences. Complicating the matter are repetitive regions subject to programmed rearrangements, as is the case with the antigen-binding domains in the Immunoglobulin (Ig) and T-cell receptor (TCR) loci. RESULTS We developed a probability-based score and visualization method to aid in distinguishing true structural variants from alignment artifacts. We demonstrate the usefulness of this method in its ability to separate real structural variants from false positives generated with existing upstream analysis tools. We validated our approach using both target-capture and whole-genome experiments. Capture sequencing reads were generated from primary lymphoid tumors, cancer cell lines and an EBV-transformed lymphoblast cell line over the Ig and TCR loci. Whole-genome sequencing reads were from a lymphoblastoid cell-line. AVAILABILITY We implement our method as an R package available at https://github.com/Eitan177/targetSeqView. Code to reproduce the figures and results are also available.
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Affiliation(s)
- Eitan Halper-Stromberg
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USADepartment of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USADepartment of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Cente
| | - Jared Steranka
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USA
| | - Kathleen H Burns
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USADepartment of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USADepartment of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Cente
| | - Sarven Sabunciyan
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USADepartment of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USA
| | - Rafael A Irizarry
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USADepartment of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Program in Human Genetics and Molecular Biology, Johns Hopkins University School of Medicine, Computational Bioscience Program, University of Colorado, Denver, Department of Molecular Biology and Genetics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Hospital, Department of Pathology, Johns Hopkins University, High Throughput Biology Center, Johns Hopkins University School of Medicine, Johns Hopkins University, Center for Epigenetics, Johns Hopkins University School of Medicine, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD and Department of Biostatistics and Computational Biology, Dana Farber Cancer Institute, Boston, Massachusetts, MA, USA
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Abstract
DNA damage response genes play vital roles in the maintenance of a healthy genome. Defects in cell cycle checkpoint and DNA repair genes, especially mutation or aberrant downregulation, are associated with a wide spectrum of human disease, including a predisposition to the development of neurodegenerative conditions and cancer. On the other hand, upregulation of DNA damage response and repair genes can also cause cancer, as well as increase resistance of cancer cells to DNA damaging therapy. In recent years, it has become evident that many of the genes involved in DNA damage repair have additional roles in tumorigenesis, most prominently by acting as transcriptional (co-)factors. Although defects in these genes are causally connected to tumor initiation, their role in tumor progression is more controversial and it seems to depend on tumor type. In some tumors like melanoma, cell cycle checkpoint/DNA repair gene upregulation is associated with tumor metastasis, whereas in a number of other cancers the opposite has been observed. Several genes that participate in the DNA damage response, such as RAD9, PARP1, BRCA1, ATM and TP53 have been associated with metastasis by a number of in vitro biochemical and cellular assays, by examining human tumor specimens by immunohistochemistry or by DNA genome-wide gene expression profiling. Many of these genes act as transcriptional effectors to regulate other genes implicated in the pathogenesis of cancer. Furthermore, they are aberrantly expressed in numerous human tumors and are causally related to tumorigenesis. However, whether the DNA damage repair function of these genes is required to promote metastasis or another activity is responsible (e.g., transcription control) has not been determined. Importantly, despite some compelling in vitro evidence, investigations are still needed to demonstrate the role of cell cycle checkpoint and DNA repair genes in regulating metastatic phenotypes in vivo.
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Affiliation(s)
- Constantinos G. Broustas
- Center for Radiological Research, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Howard B. Lieberman
- Center for Radiological Research, Columbia University College of Physicians and Surgeons, New York, New York 10032
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032
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86
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Ibuki Y, Toyooka T, Zhao X, Yoshida I. Cigarette sidestream smoke induces histone H3 phosphorylation via JNK and PI3K/Akt pathways, leading to the expression of proto-oncogenes. Carcinogenesis 2014; 35:1228-37. [PMID: 24398671 DOI: 10.1093/carcin/bgt492] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Post-translational modifications in histones have been associated with cancer. Although cigarette sidestream smoke (CSS) as well as mainstream smoke are carcinogens, the relationship between carcinogenicity and histone modifications has not yet been clarified. Here, we demonstrated that CSS induced phosphorylation of histones, involving a carcinogenic process. Treatment with CSS markedly induced the phosphorylation of histone H3 at serine 10 and 28 residues (H3S10 and H3S28), which was independent from the cell cycle, in the human pulmonary epithelial cell model, A549 and normal human lung fibroblasts, MRC-5 and WI-38. Using specific inhibitors and small interfering RNA, the phosphorylation of H3S10 was found to be mediated by c-jun N-terminal kinase (JNK) and phosphoinositide 3-kinase (PI3K)/Akt pathways. These pathways were different from that of the CSS-induced phosphorylation of histone H2AX (γ-H2AX) mediated by Ataxia telangiectasia-mutated (ATM) and ATM-Rad3-related (ATR) protein kinases. A chromatin immunoprecipitation assay revealed that the phosphorylation of H3S10 was increased in the promoter sites of the proto-oncogenes, c-fos and c-jun, which indicated that CSS plays a role in tumor promotion. Because the phosphorylation of H3S10 was decreased in the aldehyde-removed CSS and was significantly induced by treatment with formaldehyde, aldehydes are suspected to partially contribute to this phosphorylation. These findings suggested that any chemicals in CSS, including aldehydes, phosphorylate H3S10 via JNK and PI3K/Akt pathways, which is different from the DNA damage response, resulting in tumor promotion.
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Affiliation(s)
- Yuko Ibuki
- Institute for Environmental Sciences, University of Shizuoka, Yada 52-1, Suruga-ku, Shizuoka 422-8526, Japan
| | - Tatsushi Toyooka
- Institute for Environmental Sciences, University of Shizuoka, Yada 52-1, Suruga-ku, Shizuoka 422-8526, Japan
| | - Xiaoxu Zhao
- Institute for Environmental Sciences, University of Shizuoka, Yada 52-1, Suruga-ku, Shizuoka 422-8526, Japan
| | - Ikuma Yoshida
- Institute for Environmental Sciences, University of Shizuoka, Yada 52-1, Suruga-ku, Shizuoka 422-8526, Japan
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87
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Bcl2 overexpression rescues the hematopoietic stem cell defects in Ku70-deficient mice by restoration of quiescence. Blood 2014; 123:1002-11. [PMID: 24394664 DOI: 10.1182/blood-2013-08-521716] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
DNA repair is essential for hematopoietic stem cell (HSC) maintenance. Ku70 is a key component of the nonhomologous end-joining pathway, which is the major pathway for DNA double-strand break repair. We find that HSCs from Ku70-deficient mice are severely defective in self-renewal, competitive repopulation, and bone marrow (BM) hematopoietic niche occupancy and that loss of quiescence results in a dramatic defect in the maintenance of Ku70-deficient HSCs. Interestingly, although overexpression of Bcl2 does not rescue the severe combined immunodeficiency phenotype in Ku70-deficient mice, overexpression of Bcl2 in Ku70-deficient HSCs almost completely rescued the impaired HSC quiescence, repopulation, and BM hematopoietic niche occupancy capacities. Together, our data indicate that the HSC maintenance defect of Ku70-deficient mice is due to the loss of HSC quiescent populations, whereas overexpression of Bcl2 rescues the HSC defect in Ku70-deficient mice by restoration of quiescence. Our study uncovers a novel role of Bcl2 in HSC quiescence regulation.
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88
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Wang Y, Xiao R, Wang H, Cheng Z, Li W, Zhu G, Wang Y, Ma H. The Arabidopsis RAD51 paralogs RAD51B, RAD51D and XRCC2 play partially redundant roles in somatic DNA repair and gene regulation. THE NEW PHYTOLOGIST 2014; 201:292-304. [PMID: 24102485 DOI: 10.1111/nph.12498] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Accepted: 08/14/2013] [Indexed: 05/12/2023]
Abstract
The eukaryotic RAD51 gene family has seven ancient paralogs conserved between plants and animals. Among these, RAD51, DMC1, RAD51C and XRCC3 are important for homologous recombination and/or DNA repair, whereas single mutants in RAD51B, RAD51D or XRCC2 show normal meiosis, and the lineages they represent diverged from each other evolutionarily later than the other four paralogs, suggesting possible functional redundancy. The function of Arabidopsis RAD51B, RAD51D and XRCC2 genes in mitotic DNA repair and meiosis was analyzed using molecular genetic, cytological and transcriptomic approaches. The relevant double and triple mutants displayed normal vegetative and reproductive growth. However, the triple mutant showed greater sensitivity than single or double mutants to DNA damage by bleomycin. RNA-Seq transcriptome analysis supported the idea that the triple mutant showed DNA damage similar to that caused by bleomycin. On bleomycin treatment, many genes were altered in the wild-type but not in the triple mutant, suggesting that the RAD51 paralogs have roles in the regulation of gene transcription, providing an explanation for the hypersensitive phenotype of the triple mutant to bleomycin. Our results provide strong evidence that Arabidopsis XRCC2, RAD51B and RAD51D have complex functions in somatic DNA repair and gene regulation, arguing for further studies of these ancient genes that have been maintained in both plants and animals during their long evolutionary history.
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Affiliation(s)
- Yingxiang Wang
- State Key Laboratory of Genetic Engineering and Institute of Genetics, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Rong Xiao
- Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
| | - Haifeng Wang
- State Key Laboratory of Genetic Engineering and Institute of Genetics, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
| | - Zhihao Cheng
- State Key Laboratory of Genetic Engineering and Institute of Genetics, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Wuxing Li
- Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
| | - Genfeng Zhu
- State Key Laboratory of Genetic Engineering and Institute of Genetics, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Ying Wang
- State Key Laboratory of Genetic Engineering and Institute of Genetics, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China
| | - Hong Ma
- State Key Laboratory of Genetic Engineering and Institute of Genetics, Institute of Plant Biology, Center for Evolutionary Biology, School of Life Sciences, Fudan University, Shanghai, 200433, China
- Department of Biology, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, 16802, USA
- Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China
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89
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Slatter TL, Park L, Anderson K, Lailai-Tasmania V, Herbison P, Clow W, Royds JA, Devenish C, Hung NA. Smoking during pregnancy causes double-strand DNA break damage to the placenta. Hum Pathol 2014; 45:17-26. [DOI: 10.1016/j.humpath.2013.07.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 07/17/2013] [Accepted: 07/18/2013] [Indexed: 10/26/2022]
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90
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Intratumoral Hypoxia as the Genesis of Genetic Instability and Clinical Prognosis in Prostate Cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 772:189-204. [DOI: 10.1007/978-1-4614-5915-6_9] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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91
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Shen H, Liu J, Wang Y, Lian H, Wang J, Xing L, Yan X, Wang J, Zhang X. Aflatoxin G1-induced oxidative stress causes DNA damage and triggers apoptosis through MAPK signaling pathway in A549 cells. Food Chem Toxicol 2013; 62:661-9. [DOI: 10.1016/j.fct.2013.09.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 08/30/2013] [Accepted: 09/24/2013] [Indexed: 11/16/2022]
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92
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Elinav E, Nowarski R, Thaiss CA, Hu B, Jin C, Flavell RA. Inflammation-induced cancer: crosstalk between tumours, immune cells and microorganisms. Nat Rev Cancer 2013; 13:759-71. [PMID: 24154716 DOI: 10.1038/nrc3611] [Citation(s) in RCA: 1371] [Impact Index Per Article: 124.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Inflammation is a fundamental innate immune response to perturbed tissue homeostasis. Chronic inflammatory processes affect all stages of tumour development as well as therapy. In this Review, we outline the principal cellular and molecular pathways that coordinate the tumour-promoting and tumour-antagonizing effects of inflammation and we discuss the crosstalk between cancer development and inflammatory processes. In addition, we discuss the recently suggested role of commensal microorganisms in inflammation-induced cancer and we propose that understanding this microbial influence will be crucial for targeted therapy in modern cancer treatment.
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Affiliation(s)
- Eran Elinav
- 1] Department of Immunology, Weizmann Institute of Science, 100 Herzl Street, Rehovot 76100, Israel. [2]
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93
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Morgenroth A, Vogg ATJ, Zlatopolskiy BD, Siluschek M, Oedekoven C, Mottaghy FM. Breaking the invulnerability of cancer stem cells: two-step strategy to kill the stem-like cell subpopulation of multiple myeloma. Mol Cancer Ther 2013; 13:144-53. [PMID: 24174494 DOI: 10.1158/1535-7163.mct-13-0240] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In multiple myeloma, the presence of highly resistant cancer stem cells (CSC) that are responsible for tumor metastasis and relapse has been proven. Evidently, for achieving complete response, new therapeutic paradigms that effectively eradicate both, CSCs and bulk cancer populations, need to be developed. For achieving that goal, an innovative two-step treatment combining targeting of thymidine de novo synthesis pathway and a nanoirradiation by the Auger electron emitting thymidine analogue (123/125)I-5-iodo-4'-thio-2'-deoxyuridine ((123/125)I-ITdU) could be a promising approach. The pretreatment with thymidylate synthase inhibitor 5-fluoro-2'-deoxyuridine (FdUrd, 1 μmol/L for 1 hour) efficiently induced proliferation and terminal differentiation of isolated myeloma stem-like cells. Moreover, FdUrd stimulation led to a decreased activity of a functional CSC marker, aldehyde dehydrogenase (ALDH). The metabolic conditioning by FdUrd emerged to be essential for enhanced incorporation of (125)I-ITdU (incubation with 50 kBq/2 × 10(4) cells for 4 days) and, consequently, for the induction of irreparable DNA damage. (125)I-ITdU showed a pronounced antimyeloma effect on isolated tumor stem-like cells. More than 85% of the treated cells were apoptotic, despite activation of DNA repair mechanisms. Most important, exposure of metabolically conditioned cells to (125)I-ITdU resulted in a complete inhibition of clonogenic recovery. This is the first report showing that pretreatment with FdUrd sensitizes the stem-like cell compartment in multiple myeloma to apoptosis induced by (125)I-ITdU-mediated nanoirradiation of DNA.
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Affiliation(s)
- Agnieszka Morgenroth
- Corresponding Author: Agnieszka Morgenroth, Department for Nuclear Medicine, University Aachen, RWTH, Pauwelsstrasse 30, D-52074 Aachen, Germany.
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94
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DNA double-strand breaks: linking gene expression to chromosome morphology and mobility. Chromosoma 2013; 123:103-15. [DOI: 10.1007/s00412-013-0432-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 08/06/2013] [Accepted: 08/08/2013] [Indexed: 11/27/2022]
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95
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Xu E, Gong Y, Gu J, Jie L, Ajani JA, Wu X. Risk assessment of esophageal adenocarcinoma using γ-H2AX assay. Cancer Epidemiol Biomarkers Prev 2013; 22:1797-804. [PMID: 23904462 DOI: 10.1158/1055-9965.epi-13-0485] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Mutagen-induced DNA damage as measured in peripheral blood lymphocytes (PBL) has been associated with increased risks of cancers. The formation of γ-H2AX is an early cellular response to DNA double-strand breaks (DSB). We hypothesize that higher level of radiation-induced γ-H2AX in PBLs may be associated with an increased risk of esophageal adenocarcinoma. METHODS Laser scanning cytometer-based immunocytochemical method was used to measure baseline and irradiation-induced γ-H2AX levels in PBLs from 211 patients with esophageal adenocarcinoma and 211 healthy controls. The ratio of induced γ-H2AX level to baseline level was used to evaluate individual susceptibility to DSBs. Relative risks for esophageal adenocarcinoma associated with γ-H2AX were assessed by multivariable logistic regression analysis. RESULTS Radiation-induced γ-H2AX level and the γ-H2AX ratio were significantly higher in cases than in controls. Dichotomized at the median in controls, a significantly increased risk for esophageal adenocarcinoma was observed in association with high γ-H2AX ratio [OR = 2.94; 95% confidence interval (CI), 1.83-4.72]. Quartile analyses showed significant dose-response associations between higher γ-H2AX ratio and increased risk of esophageal adenocarcinoma (Ptrend, 1.64E-06). In addition, joint effect between γ-H2AX ratio and smoking was observed: smokers who had high γ-H2AX ratio exhibited the highest risk of esophageal adenocarcinoma (OR = 5.53; 95% CI, 2.71-11.25) compared with never smokers with low γ-H2AX ratio. CONCLUSION Radiation-induced DNA damage assessed by γ-H2AX ratio is associated with an increased risk of esophageal adenocarcinoma. IMPACT γ-H2AX assay is a new and robust method to measure DSB damage in PBLs, which can be used to assess mutagen sensitivity and esophageal adenocarcinoma risk.
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Affiliation(s)
- Enping Xu
- Authors' Affiliations: Departments of Epidemiology and Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; and Department of Pathology, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
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96
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Cui J, Liu J, Wu S, Wang Y, Shen H, Xing L, Wang J, Yan X, Zhang X. Oxidative DNA damage is involved in ochratoxin A-induced G2 arrest through ataxia telangiectasia-mutated (ATM) pathways in human gastric epithelium GES-1 cells in vitro. Arch Toxicol 2013; 87:1829-40. [PMID: 23515941 DOI: 10.1007/s00204-013-1043-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 03/08/2013] [Indexed: 01/17/2023]
Abstract
Ochratoxin A (OTA), one of the most abundant mycotoxin food contaminants, is classified as "possibly carcinogenic to humans." Our previous study showed that OTA could induce a G2 arrest in immortalized human gastric epithelium cells (GES-1). To explore the putative roles of oxidative DNA damage and the ataxia telangiectasia-mutated (ATM) pathways on the OTA-induced G2 arrest, the current study systematically evaluated the roles of reactive oxygen species (ROS) production, DNA damage, and ATM-dependent pathway activation on the OTA-induced G2 phase arrest in GES-1 cells. The results showed that OTA exposure elevated intracellular ROS production, which directly induced DNA damage and increased the levels of 8-OHdG and DNA double-strand breaks (DSBs). In addition, it was found that OTA treatment induced the phosphorylation of the ATM protein, as well as its downstream molecules Chk2 and p53, in response to DNA DSBs. Inhibition of ATM by the pharmacological inhibitor caffeine or siRNA effectively prevented the activation of ATM-dependent pathways and rescued the G2 arrest elicited by OTA. Finally, pretreatment with the antioxidant N-acetyl-L-cysteine (NAC) reduced the OTA-induced DNA DSBs, ATM phosphorylation, and G2 arrest. In conclusion, the results of this study suggested that OTA-induced oxidative DNA damage triggered the ATM-dependent pathways, which ultimately elicited a G2 arrest in GES-1 cells.
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Affiliation(s)
- Jinfeng Cui
- Department of Pathology, The Second Hospital, Hebei Medical University, No. 215, Heping Western Road, Shijiazhuang, Hebei, People's Republic of China
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97
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Boboila C, Alt FW, Schwer B. Classical and alternative end-joining pathways for repair of lymphocyte-specific and general DNA double-strand breaks. Adv Immunol 2013; 116:1-49. [PMID: 23063072 DOI: 10.1016/b978-0-12-394300-2.00001-6] [Citation(s) in RCA: 203] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Classical nonhomologous end joining (C-NHEJ) is one of the two major known pathways for the repair of DNA double-strand breaks (DSBs) in mammalian cells. Our understanding of C-NHEJ has been derived, in significant part, through studies of programmed physiologic DNA DSBs formed during V(D)J recombination in the developing immune system. Studies of immunoglobulin heavy-chain (IgH) class-switch recombination (CSR) also have revealed that there is an "alternative" end-joining process (A-EJ) that can function, relatively robustly, in the repair of DSBs in activated mature B lymphocytes. This A-EJ process has also been implicated in the formation of oncogenic translocations found in lymphoid tumors. In this review, we discuss our current understanding of C-NHEJ and A-EJ in the context of V(D)J recombination, CSR, and the formation of chromosomal translocations.
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Affiliation(s)
- Cristian Boboila
- Howard Hughes Medical Institute, Immune Disease Institute, Program in Cellular and Molecular Medicine, Children's Hospital Boston, Boston, Massachusetts, USA
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98
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Ježková L, Falk M, Falková I, Davídková M, Bačíková A, Štefančíková L, Vachelová J, Michaelidesová A, Lukášová E, Boreyko A, Krasavin E, Kozubek S. Function of chromatin structure and dynamics in DNA damage, repair and misrepair: γ-rays and protons in action. Appl Radiat Isot 2013; 83 Pt B:128-36. [PMID: 23415104 DOI: 10.1016/j.apradiso.2013.01.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/09/2013] [Accepted: 01/10/2013] [Indexed: 11/26/2022]
Abstract
According to their physical characteristics, protons and ion beams promise a revolution in cancer radiotherapy. Curing protocols however reflect rather the empirical knowledge than experimental data on DNA repair. This especially holds for the spatio-temporal organization of repair processes in the context of higher-order chromatin structure-the problematics addressed in this work. The consequences for the mechanism of chromosomal translocations are compared for gamma rays and proton beams.
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Affiliation(s)
- Lucie Ježková
- Institute of Biophysics Brno, Academy of Sciences of the Czech Republic, Brno, Czech Republic; Joint Institute for Nuclear Research, Dubna, Moscow Region, Russia; Institute of Chemical Technology Prague, Prague, Czech Republic
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99
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He Y, Gong Y, Lin J, Chang DW, Gu J, Roth JA, Wu X. Ionizing radiation-induced γ-H2AX activity in whole blood culture and the risk of lung cancer. Cancer Epidemiol Biomarkers Prev 2013; 22:443-51. [PMID: 23300022 DOI: 10.1158/1055-9965.epi-12-0794] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Phenotypic biomarkers of DNA damage repair may enhance cancer risk prediction. The γ-H2AX formed at the sites of double-strand break (DSB) after ionizing radiation is a specific marker of DNA damage. METHODS In an ongoing case-control study, the baseline and ionizing radiation-induced γ-H2AX levels in peripheral blood lymphocytes (PBL) from frequency-matched 306 untreated patients with lung cancer and 306 controls were measured by a laser scanning cytometer-based immunocytochemical method. The ratio of ionizing radiation-induced γ-H2AX level to the baseline was used to evaluate interindividual variation of DSB damage response and to assess the risk of lung cancer by using unconditional multivariable logistic regression with adjustment of age, sex, ethnicity, smoking status, family history of lung cancer, dust exposure, and emphysema. RESULTS The mean γ-H2AX ratio was significantly higher in cases than controls (1.46 ± 0.14 vs. 1.41 ± 0.12, P < 0.001). Dichotomized at the median in controls, high γ-H2AX ratio was significantly associated with increased risk of lung cancer [OR = 2.43; 95% confidence interval (CI): 1.66-3.56]. There was also a significant dose-response relationship between γ-H2AX ratio and lung cancer risk in quartile analysis. Analysis of joint effects with other epidemiologic risk factors revealed elevated risk with increasing number of risk factors. CONCLUSION γ-H2AX activity as shown by measuring DSB damage in ionizing radiation-irradiated PBLs may be a novel phenotypic marker of lung cancer risk. IMPACT γ-H2AX assay is a robust and quantifiable image-based cytometer method that measures mutagen-induced DSB response in PBLs as a potential biomarker in lung cancer risk assessment.
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Affiliation(s)
- Yonggang He
- Corresponding Author: Xifeng Wu, Department of Epidemiology, Unit 1340, The University of Texas MD Anderson Cancer Center, 1155 Herman Pressler, Houston, TX 77030, USA
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100
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Lucas D, Delgado-García JM, Escudero B, Albo C, Aza A, Acín-Pérez R, Torres Y, Moreno P, Enríquez JA, Samper E, Blanco L, Fairén A, Bernad A, Gruart A. Increased learning and brain long-term potentiation in aged mice lacking DNA polymerase μ. PLoS One 2013; 8:e53243. [PMID: 23301049 PMCID: PMC3536760 DOI: 10.1371/journal.pone.0053243] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 11/27/2012] [Indexed: 01/14/2023] Open
Abstract
A definitive consequence of the aging process is the progressive deterioration of higher cognitive functions. Defects in DNA repair mechanisms mostly result in accelerated aging and reduced brain function. DNA polymerase µ is a novel accessory partner for the non-homologous end-joining DNA repair pathway for double-strand breaks, and its deficiency causes reduced DNA repair. Using associative learning and long-term potentiation experiments, we demonstrate that Polµ−/− mice, however, maintain the ability to learn at ages when wild-type mice do not. Expression and biochemical analyses suggest that brain aging is delayed in Polµ−/− mice, being associated with a reduced error-prone DNA oxidative repair activity and a more efficient mitochondrial function. This is the first example in which the genetic ablation of a DNA-repair function results in a substantially better maintenance of learning abilities, together with fewer signs of brain aging, in old mice.
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Affiliation(s)
- Daniel Lucas
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/CSIC, Madrid, Spain
| | | | - Beatriz Escudero
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Development and Cardiac Repair Department, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Carmen Albo
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Development and Cardiac Repair Department, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Ana Aza
- Centro de Biología Molecular Severo Ochoa, Campus de Cantoblanco, Madrid, Spain
| | - Rebeca Acín-Pérez
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Development and Cardiac Repair Department, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Yaima Torres
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Development and Cardiac Repair Department, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Paz Moreno
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - José Antonio Enríquez
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Development and Cardiac Repair Department, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Enrique Samper
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Development and Cardiac Repair Department, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Luis Blanco
- Centro de Biología Molecular Severo Ochoa, Campus de Cantoblanco, Madrid, Spain
| | - Alfonso Fairén
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas - Universidad Miguel Hernández, San Juan de Alicante, Spain
| | - Antonio Bernad
- Department of Regenerative Cardiology, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Development and Cardiac Repair Department, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- Translational Research Platform, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
- * E-mail: (AB); (AG)
| | - Agnès Gruart
- División de Neurociencias, Universidad Pablo de Olavide, Sevilla, Spain
- * E-mail: (AB); (AG)
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