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Khajedehi N, Fathi R, Akbarinejad V, Gourabi H. Oocyte Vitrification Reduces its Capability to Repair Sperm DNA Fragmentation and Impairs Embryonic Development. Reprod Sci 2024; 31:1256-1267. [PMID: 38151654 DOI: 10.1007/s43032-023-01419-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 11/29/2023] [Indexed: 12/29/2023]
Abstract
Oocytes play a crucial role in repairing sperm DNA damage, which can affect the next generation; however, certain factors can impair this ability. This study examined whether oocyte vitrification, a widely used method for fertility preservation, negatively affects repair ability. Male DBA/2 mice (n = 28) were injected with 101.60 µmol/100 g body weight of tert-Butyl hydroperoxide (tBHP) for 14 days to induce sperm DNA damage. Histological changes, sperm functions, and DNA fragmentation were assessed using the TUNEL assay. Cumulus-oocyte-complexes (COCs) of superovulated female DBA/2 mice (n = 28) were vitrified using the Cryotop method. Fresh and vitrified oocytes were then fertilized by tBHP-treated and untreated sperms, and subsequent embryonic development was monitored. Additionally, the expression of Mre11a, Rad51, Brca1, and Xrcc4 was assessed in resulting zygotes and blastocysts using real-time PCR. The sperm tBHP treatment reduced differentiated spermatogenic cells in the testicular tissue, sperm concentration, and motility, while increasing DNA fragmentation (P < 0.05). The fertilization rate was decreased in the tBHP-treated sperm-vitrified oocyte group (P < 0.05), and the two-cell rate diminished in tBHP-treated sperm-fresh and vitrified oocyte groups (P < 0.05). The four-cell to blastocyst rate decreased in the untreated sperm-vitrified oocyte and the tBHP-treated sperm-fresh and vitrified oocyte groups (P < 0.05), and the tBHP-treated sperm-vitrified oocyte groups had the lowest blastocyst rate. In zygotes, Brca1 was upregulated in the tBHP-treated sperm-vitrified oocyte group (P < 0.05). Also, in blastocysts, Rad51, Brca1, and Xrcc4 were significantly upregulated in the untreated sperm-vitrified oocytes group (P < 0.05). Damages to the oocyte due to vitrification can disrupt the repair of sperm DNA fragmentation and consequently impair the embryo development.
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Affiliation(s)
- Niloofar Khajedehi
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
- Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Rouhollah Fathi
- Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
| | - Vahid Akbarinejad
- Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Hamid Gourabi
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
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Liu Q, Peng Q, Zhang B, Tan Y. X-ray cross-complementing family: the bridge linking DNA damage repair and cancer. J Transl Med 2023; 21:602. [PMID: 37679817 PMCID: PMC10483876 DOI: 10.1186/s12967-023-04447-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 08/17/2023] [Indexed: 09/09/2023] Open
Abstract
Genomic instability is a common hallmark of human tumours. As a carrier of genetic information, DNA is constantly threatened by various damaging factors that, if not repaired in time, can affect the transmission of genetic information and lead to cellular carcinogenesis. In response to these threats, cells have evolved a range of DNA damage response mechanisms, including DNA damage repair, to maintain genomic stability. The X-ray repair cross-complementary gene family (XRCC) comprises an important class of DNA damage repair genes that encode proteins that play important roles in DNA single-strand breakage and DNA base damage repair. The dysfunction of the XRCC gene family is associated with the development of various tumours. In the context of tumours, mutations in XRCC and its aberrant expression, result in abnormal DNA damage repair, thus contributing to the malignant progression of tumour cells. In this review, we summarise the significant roles played by XRCC in diverse tumour types. In addition, we discuss the correlation between the XRCC family members and tumour therapeutic sensitivity.
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Affiliation(s)
- Qiang Liu
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, 283 Tongzipo Road, Changsha, 410013, Hunan, China
- NHC Key Laboratory of Human Stem Cell and Reproductive Engineering, School of Basic Medical Sciences, Institute of Reproductive and Stem Cell Engineering, Central South University, Changsha, 410078, Hunan, China
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, 410008, Hunan, China
| | - Qiu Peng
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, 283 Tongzipo Road, Changsha, 410013, Hunan, China
| | - Bin Zhang
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, 283 Tongzipo Road, Changsha, 410013, Hunan, China.
- Department of Histology and Embryology, Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China.
| | - Yueqiu Tan
- Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, 283 Tongzipo Road, Changsha, 410013, Hunan, China.
- NHC Key Laboratory of Human Stem Cell and Reproductive Engineering, School of Basic Medical Sciences, Institute of Reproductive and Stem Cell Engineering, Central South University, Changsha, 410078, Hunan, China.
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, 410008, Hunan, China.
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Reuss DE, Downing SM, Camacho CV, Wang YD, Piro RM, Herold-Mende C, Wang ZQ, Hofmann TG, Sahm F, von Deimling A, McKinnon PJ, Frappart PO. Simultaneous Nbs1 and p53 inactivation in neural progenitors triggers high-grade gliomas. Neuropathol Appl Neurobiol 2023; 49:e12915. [PMID: 37296499 DOI: 10.1111/nan.12915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 04/25/2023] [Accepted: 06/02/2023] [Indexed: 06/12/2023]
Abstract
AIMS Nijmegen breakage syndrome (NBS) is a rare autosomal recessive disorder caused by hypomorphic mutations of NBS1. NBS1 is a member of the MRE11-RAD50-NBS1 (MRN) complex that binds to DNA double-strand breaks and activates the DNA damage response (DDR). Nbs1 inactivation in neural progenitor cells leads to microcephaly and premature death. Interestingly, p53 homozygous deletion rescues the NBS1-deficient phenotype allowing long-term survival. The objective of this work was to determine whether simultaneous inactivation of Nbs1 and p53 in neural progenitors triggered brain tumorigenesis and if so in which category this tumour could be classified. METHODS We generated a mouse model with simultaneous genetic inactivation of Nbs1 and p53 in embryonic neural stem cells and analysed the arising tumours with in-depth molecular analyses including immunohistochemistry, array comparative genomic hybridisation (aCGH), whole exome-sequencing and RNA-sequencing. RESULTS NBS1/P53-deficient mice develop high-grade gliomas (HGG) arising in the olfactory bulbs and in the cortex along the rostral migratory stream. In-depth molecular analyses using immunohistochemistry, aCGH, whole exome-sequencing and RNA-sequencing revealed striking similarities to paediatric human HGG with shared features with radiation-induced gliomas (RIGs). CONCLUSIONS Our findings show that concomitant inactivation of Nbs1 and p53 in mice promotes HGG with RIG features. This model could be useful for preclinical studies to improve the prognosis of these deadly tumours, but it also highlights the singularity of NBS1 among the other DNA damage response proteins in the aetiology of brain tumours.
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Affiliation(s)
- David E Reuss
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Consortium for Translational Cancer Research (DKTK), Heidelberg, Germany
- Department of Neuropathology, Institute of Pathology, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Susanna M Downing
- Center for Pediatric Neurological Disease Research, St. Jude Translational Neuroscience, Departments of Genetics and Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Cristel V Camacho
- Center for Pediatric Neurological Disease Research, St. Jude Translational Neuroscience, Departments of Genetics and Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Yong-Dong Wang
- Center for Pediatric Neurological Disease Research, St. Jude Translational Neuroscience, Departments of Genetics and Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Rosario M Piro
- Dipartimento di Elettronica, Informazione e Bioingegneria (DEIB), Politecnico di Milano, Milan, Italy
| | - Christel Herold-Mende
- Department of Neurosurgery, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Zhao-Qi Wang
- Leibniz Institute on Ageing-Fritz Lipmann Institute, Jena, Germany
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Thomas G Hofmann
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Felix Sahm
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Consortium for Translational Cancer Research (DKTK), Heidelberg, Germany
- Department of Neuropathology, Institute of Pathology, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Andreas von Deimling
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Consortium for Translational Cancer Research (DKTK), Heidelberg, Germany
- Department of Neuropathology, Institute of Pathology, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Peter J McKinnon
- Center for Pediatric Neurological Disease Research, St. Jude Translational Neuroscience, Departments of Genetics and Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Pierre-Olivier Frappart
- Institute of Toxicology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Petroni M, La Monica V, Fabretti F, Augusto M, Battaglini D, Polonara F, Di Giulio S, Giannini G. The Multiple Faces of the MRN Complex: Roles in Medulloblastoma and Beyond. Cancers (Basel) 2023; 15:3599. [PMID: 37509263 PMCID: PMC10377613 DOI: 10.3390/cancers15143599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/09/2023] [Accepted: 07/10/2023] [Indexed: 07/30/2023] Open
Abstract
Hypomorphic mutations in MRN complex genes are frequently found in cancer, supporting their role as oncosuppressors. However, unlike canonical oncosuppressors, MRN proteins are often overexpressed in tumor tissues, where they actively work to counteract DSBs induced by both oncogene-dependent RS and radio-chemotherapy. Moreover, at the same time, MRN genes are also essential genes, since the constitutive KO of each component leads to embryonic lethality. Therefore, even though it is paradoxical, MRN genes may work as oncosuppressive, oncopromoting, and essential genes. In this review, we discussed how alterations in the MRN complex impact the physiopathology of cancer, in light of our recent discoveries on the gene-dosage-dependent effect of NBS1 in Medulloblastoma. These updates aim to understand whether MRN complex can be realistically used as a prognostic/predictive marker and/or as a therapeutic target for the treatment of cancer patients in the future.
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Affiliation(s)
- Marialaura Petroni
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
- Istituto Pasteur-Fondazione Cenci Bolognetti, 00161 Rome, Italy
| | - Veronica La Monica
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
| | - Francesca Fabretti
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
| | - Mariaconcetta Augusto
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
- Center for Life Nano- & Neuro-Science, Istituto Italiano di Tecnologia (IIT), 00161 Rome, Italy
| | - Damiana Battaglini
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
| | - Francesca Polonara
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
- Istituto Pasteur-Fondazione Cenci Bolognetti, 00161 Rome, Italy
| | - Stefano Di Giulio
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
| | - Giuseppe Giannini
- Department of Molecular Medicine, University La Sapienza, 00161 Rome, Italy
- Istituto Pasteur-Fondazione Cenci Bolognetti, 00161 Rome, Italy
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5
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Noorani I, Mischel PS, Swanton C. Leveraging extrachromosomal DNA to fine-tune trials of targeted therapy for glioblastoma: opportunities and challenges. Nat Rev Clin Oncol 2022; 19:733-743. [PMID: 36131011 DOI: 10.1038/s41571-022-00679-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/10/2022] [Indexed: 11/09/2022]
Abstract
Glioblastoma evolution is facilitated by intratumour heterogeneity, which poses a major hurdle to effective treatment. Evidence indicates a key role for oncogene amplification on extrachromosomal DNA (ecDNA) in accelerating tumour evolution and thus resistance to treatment, particularly in glioblastomas. Oncogenes contained within ecDNA can reach high copy numbers and expression levels, and their unequal segregation can result in more rapid copy number changes in response to therapy than is possible through natural selection of intrachromosomal genomic loci. Notably, targeted therapies inhibiting oncogenic pathways have failed to improve glioblastoma outcomes. In this Perspective, we outline reasons for this disappointing lack of clinical translation and present the emerging evidence implicating ecDNA as an important driver of tumour evolution. Furthermore, we suggest that through detection of ecDNA, patient selection for clinical trials of novel agents can be optimized to include those most likely to benefit based on current understanding of resistance mechanisms. We discuss the challenges to successful translation of this approach, including accurate detection of ecDNA in tumour tissue with novel technologies, development of faithful preclinical models for predicting the efficacy of novel agents in the presence of ecDNA oncogenes, and understanding the mechanisms of ecDNA formation during cancer evolution and how they could be attenuated therapeutically. Finally, we evaluate the feasibility of routine ecDNA characterization in the clinic and how this process could be integrated with other methods of molecular stratification to maximize the potential for clinical translation of precision medicines.
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Affiliation(s)
- Imran Noorani
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK.
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, UK.
| | - Paul S Mischel
- Department of Pathology, Stanford University School of Medicine and Sarafan ChEM-H, Stanford University, Stanford, CA, USA.
| | - Charles Swanton
- Cancer Evolution and Genome Instability Laboratory, The Francis Crick Institute, London, UK.
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6
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Michel N, Young HMR, Atkin ND, Arshad U, Al-Humadi R, Singh S, Manukyan A, Gore L, Burbulis IE, Wang YH, McConnell MJ. Transcription-associated DNA DSBs activate p53 during hiPSC-based neurogenesis. Sci Rep 2022; 12:12156. [PMID: 35840793 PMCID: PMC9287420 DOI: 10.1038/s41598-022-16516-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 07/11/2022] [Indexed: 11/09/2022] Open
Abstract
Neurons are overproduced during cerebral cortical development. Neural progenitor cells (NPCs) divide rapidly and incur frequent DNA double-strand breaks (DSBs) throughout cortical neurogenesis. Although half of the neurons born during neurodevelopment die, many neurons with inaccurate DNA repair survive leading to brain somatic mosaicism. Recurrent DNA DSBs during neurodevelopment are associated with both gene expression level and gene length. We used imaging flow cytometry and a genome-wide DNA DSB capture approach to quantify and map DNA DSBs during human induced pluripotent stem cell (hiPSC)-based neurogenesis. Reduced p53 signaling was brought about by knockdown (p53KD); p53KD led to elevated DNA DSB burden in neurons that was associated with gene expression level but not gene length in neural progenitor cells (NPCs). Furthermore, DNA DSBs incurred from transcriptional, but not replicative, stress lead to p53 activation in neurotypical NPCs. In p53KD NPCs, DNA DSBs accumulate at transcription start sites of genes that are associated with neurological and psychiatric disorders. These findings add to a growing understanding of how neuronal genome dynamics are engaged by high transcriptional or replicative burden during neurodevelopment.
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Affiliation(s)
- Nadine Michel
- Neuroscience Graduate Program, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Heather M Raimer Young
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Naomi D Atkin
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Umar Arshad
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Reem Al-Humadi
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Sandeep Singh
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Arkadi Manukyan
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Lana Gore
- Lieber Institute for Brain Development, 855 N. Wolfe St., Ste. 300, Baltimore, MD, 21205, USA
| | - Ian E Burbulis
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
- Sede de la Patagonia, Facultad de Medicina y Ciencias, Universidad San Sebastián, Puerto Montt, Chile
| | - Yuh-Hwa Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, 1340 Jefferson Park Avenue, Charlottesville, VA, 22908, USA
| | - Michael J McConnell
- Lieber Institute for Brain Development, 855 N. Wolfe St., Ste. 300, Baltimore, MD, 21205, USA.
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7
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Petroni M, Fabretti F, Giulio SD, Robilant VND, Monica VL, Moretti M, Belardinilli F, Bufalieri F, Anna C, Paci P, Corsi A, Smaele ED, Coni S, Canettieri G, Marcotullio LD, Wang ZQ, Giannini G. A gene dosage-dependent effect unveils NBS1 as both a haploinsufficient tumour suppressor and an essential gene for SHH-medulloblastoma. Neuropathol Appl Neurobiol 2022; 48:e12837. [PMID: 35839783 PMCID: PMC9542137 DOI: 10.1111/nan.12837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/10/2022] [Accepted: 07/05/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Inherited or somatic mutations in the MRE11, RAD50 and NBN genes increase the incidence of tumours, including medulloblastoma (MB). On the other hand, MRE11, RAD50 and NBS1 protein components of the MRN complex are often overexpressed and sometimes essential in cancer. In order to solve the apparent conundrum about the oncosuppressive or oncopromoting role of the MRN complex, we explored the functions of NBS1 in a MB prone animal model. MATERIALS AND METHODS We generated and analysed mono- or biallelic deletion of the Nbn gene in the context of the SmoA1 transgenic mouse, a SHH-dependent MB prone animal model. We used normal and tumour tissue from these animal models, primary granule cell progenitors (GCPs) from genetically modified animals, and NBS1-depleted primary MB cells, to uncover the effects of NBS1-depletion by RNA-Seq, by biochemical characterization of the SHH-pathway and the DNA damage response (DDR) as well as on the growth and clonogenic properties of GCPs. RESULTS We found that monoallelic Nbn deletion increases SmoA1-dependent MB incidence. In addition to a defective DDR, Nbn+/- GCPs show increased clonogenicity compared to Nbn+/+ GCPs, dependent on an enhanced Notch signalling. In contrast, full NbnKO impairs MB development both in SmoA1 mice and in a SHH-driven tumour allograft. CONCLUSIONS Our study indicates that Nbn is haploinsufficient for SHH-MB development while full NbnKO is epistatic on SHH-driven MB development, thus revealing a gene dosage-dependent effect of Nbn inactivation on SHH-MB development.
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Affiliation(s)
- Marialaura Petroni
- Dept. of Molecular Medicine, University La Sapienza, Rome, Italy.,Istituto Pasteur-Fondazione Cenci Bolognetti, Rome, Italy
| | | | | | | | | | - Marta Moretti
- Dept. of Experimental Medicine, University La Sapienza, Rome, Italy
| | | | | | - Coppa Anna
- Dept. of Experimental Medicine, University La Sapienza, Rome, Italy
| | - Paola Paci
- Dep. of Computer Engineering, Automation and Management, University La Sapienza, Rome, Italy.,Institute for Systems Analysis and Computer Science Antonio Ruberti, National Research Council, Rome, Italy
| | - Alessandro Corsi
- Dept. of Molecular Medicine, University La Sapienza, Rome, Italy
| | - Enrico De Smaele
- Dept. of Experimental Medicine, University La Sapienza, Rome, Italy
| | - Sonia Coni
- Dept. of Molecular Medicine, University La Sapienza, Rome, Italy
| | - Gianluca Canettieri
- Dept. of Molecular Medicine, University La Sapienza, Rome, Italy.,Istituto Pasteur-Fondazione Cenci Bolognetti, Rome, Italy
| | | | - Zhao-Qi Wang
- Leibniz Institute on Aging - Fritz Lipmann Institute (FLI) Beutenbergstrasse 11, Jena, Germany
| | - Giuseppe Giannini
- Dept. of Molecular Medicine, University La Sapienza, Rome, Italy.,Istituto Pasteur-Fondazione Cenci Bolognetti, Rome, Italy
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8
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Vincendeau E, Wei W, Zhang X, Planchais C, Yu W, Lenden-Hasse H, Cokelaer T, Pipoli da Fonseca J, Mouquet H, Adams DJ, Alt FW, Jackson SP, Balmus G, Lescale C, Deriano L. SHLD1 is dispensable for 53BP1-dependent V(D)J recombination but critical for productive class switch recombination. Nat Commun 2022; 13:3707. [PMID: 35764636 PMCID: PMC9240092 DOI: 10.1038/s41467-022-31287-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 06/13/2022] [Indexed: 11/21/2022] Open
Abstract
SHLD1 is part of the Shieldin (SHLD) complex, which acts downstream of 53BP1 to counteract DNA double-strand break (DSB) end resection and promote DNA repair via non-homologous end-joining (NHEJ). While 53BP1 is essential for immunoglobulin heavy chain class switch recombination (CSR), long-range V(D)J recombination and repair of RAG-induced DSBs in XLF-deficient cells, the function of SHLD during these processes remains elusive. Here we report that SHLD1 is dispensable for lymphocyte development and RAG-mediated V(D)J recombination, even in the absence of XLF. By contrast, SHLD1 is essential for restricting resection at AID-induced DSB ends in both NHEJ-proficient and NHEJ-deficient B cells, providing an end-protection mechanism that permits productive CSR by NHEJ and alternative end-joining. Finally, we show that this SHLD1 function is required for orientation-specific joining of AID-initiated DSBs. Our data thus suggest that 53BP1 promotes V(D)J recombination and CSR through two distinct mechanisms: SHLD-independent synapsis of V(D)J segments and switch regions within chromatin, and SHLD-dependent protection of AID-DSB ends against resection.
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Affiliation(s)
- Estelle Vincendeau
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France
| | - Wenming Wei
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France
| | - Xuefei Zhang
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine at Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
- Biomedical Pioneering Innovation Center (BIOPIC) and Beijing Advanced Innovation Center for Genomics (ICG), Peking University, Beijing, 100871, China
| | - Cyril Planchais
- Institut Pasteur, Université de Paris, INSERM U1222, Laboratory of Humoral Immunology, 75015, Paris, France
| | - Wei Yu
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France
| | - Hélène Lenden-Hasse
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France
| | - Thomas Cokelaer
- Institut Pasteur, Plate-forme Technologique Biomics, Centre de Ressources et Recherches Technologiques, 75015, Paris, France
- Institut Pasteur, Hub de Bioinformatique et Biostatistique, Département de Biologie Computationnelle, 75015, Paris, France
| | - Juliana Pipoli da Fonseca
- Institut Pasteur, Plate-forme Technologique Biomics, Centre de Ressources et Recherches Technologiques, 75015, Paris, France
| | - Hugo Mouquet
- Institut Pasteur, Université de Paris, INSERM U1222, Laboratory of Humoral Immunology, 75015, Paris, France
| | - David J Adams
- Wellcome Trust Sanger Institute, Cambridge, CB10 1SA, UK
| | - Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine at Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - Stephen P Jackson
- Wellcome Trust/Cancer Research UK Gurdon Institute, Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QN, UK
| | - Gabriel Balmus
- UK Dementia Research Institute at University of Cambridge, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0AH, UK
| | - Chloé Lescale
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France.
| | - Ludovic Deriano
- Institut Pasteur, Université Paris Cité, INSERM U1223, Équipe Labellisée Ligue Contre Le Cancer, Genome Integrity, Immunity and Cancer Unit, 75015, Paris, France.
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Abstract
The rapid development of CRISPR-Cas genome editing tools has greatly changed the way to conduct research and holds tremendous promise for clinical applications. During genome editing, CRISPR-Cas enzymes induce DNA breaks at the target sites and subsequently the DNA repair pathways are recruited to generate diverse editing outcomes. Besides off-target cleavage, unwanted editing outcomes including chromosomal structural variations and exogenous DNA integrations have recently raised concerns for clinical safety. To eliminate these unwanted editing byproducts, we need to explore the underlying mechanisms for the formation of diverse editing outcomes from the perspective of DNA repair. Here, we describe the involved DNA repair pathways in sealing Cas enzyme-induced DNA double-stranded breaks and discuss the origins and effects of unwanted editing byproducts on genome stability. Furthermore, we propose the potential risk of inhibiting DNA repair pathways to enhance gene editing. The recent combined studies of DNA repair and CRISPR-Cas editing provide a framework for further optimizing genome editing to enhance editing safety.
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10
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Simovic M, Ernst A. Chromothripsis, DNA repair and checkpoints defects. Semin Cell Dev Biol 2021; 123:110-114. [PMID: 33589336 DOI: 10.1016/j.semcdb.2021.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/05/2021] [Indexed: 11/28/2022]
Abstract
Chromothripsis is a unique form of genome instability characterized by tens to hundreds of DNA double-strand breaks on one or very few chromosomes, followed by error-prone repair. The derivative chromosome(s) display massive rearrangements, which lead to the loss of tumor suppressor function and to the activation of oncogenes. Chromothripsis plays a major role in cancer as well as in other conditions, such as congenital diseases. In this review, we discuss the repair processes involved in the rejoining of the chromosome fragments, the role of DNA repair and checkpoint defects as a cause for chromothripsis as well as DNA repair defects resulting from chromothripsis. Finally, we consider clinical implications and potential therapeutic vulnerabilities that could be utilized to eliminate tumor cells with chromothripsis.
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Affiliation(s)
- Milena Simovic
- Group Genome Instability in Tumors, German Cancer Research Centre (DKFZ), Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, Germany
| | - Aurélie Ernst
- Group Genome Instability in Tumors, German Cancer Research Centre (DKFZ), Heidelberg, Germany.
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11
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Garcia-Lopez J, Kumar R, Smith KS, Northcott PA. Deconstructing Sonic Hedgehog Medulloblastoma: Molecular Subtypes, Drivers, and Beyond. Trends Genet 2020; 37:235-250. [PMID: 33272592 DOI: 10.1016/j.tig.2020.11.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/29/2020] [Accepted: 11/02/2020] [Indexed: 02/07/2023]
Abstract
Medulloblastoma (MB) is a highly malignant cerebellar tumor predominantly diagnosed during childhood. Driven by pathogenic activation of sonic hedgehog (SHH) signaling, SHH subgroup MB (SHH-MB) accounts for nearly one-third of diagnoses. Extensive molecular analyses have identified biologically and clinically relevant intertumoral heterogeneity among SHH-MB tumors, prompting the recognition of novel subtypes. Beyond germline and somatic mutations promoting constitutive SHH signaling, driver alterations affect a multitude of pathways and molecular processes, including TP53 signaling, chromatin modulation, and post-transcriptional gene regulation. Here, we review recent advances in the underpinnings of SHH-MB in the context of molecular subtypes, clarify novel somatic and germline drivers, highlight cellular origins and developmental hierarchies, and describe the composition of the tumor microenvironment and its putative role in tumorigenesis.
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Affiliation(s)
- Jesus Garcia-Lopez
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Rahul Kumar
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Kyle S Smith
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Paul A Northcott
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA.
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12
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Forrer Charlier C, Martins RAP. Protective Mechanisms Against DNA Replication Stress in the Nervous System. Genes (Basel) 2020; 11:E730. [PMID: 32630049 PMCID: PMC7397197 DOI: 10.3390/genes11070730] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/25/2020] [Accepted: 06/25/2020] [Indexed: 02/06/2023] Open
Abstract
The precise replication of DNA and the successful segregation of chromosomes are essential for the faithful transmission of genetic information during the cell cycle. Alterations in the dynamics of genome replication, also referred to as DNA replication stress, may lead to DNA damage and, consequently, mutations and chromosomal rearrangements. Extensive research has revealed that DNA replication stress drives genome instability during tumorigenesis. Over decades, genetic studies of inherited syndromes have established a connection between the mutations in genes required for proper DNA repair/DNA damage responses and neurological diseases. It is becoming clear that both the prevention and the responses to replication stress are particularly important for nervous system development and function. The accurate regulation of cell proliferation is key for the expansion of progenitor pools during central nervous system (CNS) development, adult neurogenesis, and regeneration. Moreover, DNA replication stress in glial cells regulates CNS tumorigenesis and plays a role in neurodegenerative diseases such as ataxia telangiectasia (A-T). Here, we review how replication stress generation and replication stress response (RSR) contribute to the CNS development, homeostasis, and disease. Both cell-autonomous mechanisms, as well as the evidence of RSR-mediated alterations of the cellular microenvironment in the nervous system, were discussed.
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Affiliation(s)
| | - Rodrigo A. P. Martins
- Programa de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil;
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13
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DNA-PK in human malignant disorders: Mechanisms and implications for pharmacological interventions. Pharmacol Ther 2020; 215:107617. [PMID: 32610116 DOI: 10.1016/j.pharmthera.2020.107617] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/15/2020] [Indexed: 12/12/2022]
Abstract
The DNA-PK holoenzyme is a fundamental element of the DNA damage response machinery (DDR), which is responsible for cellular genomic stability. Consequently, and predictably, over the last decades since its identification and characterization, numerous pre-clinical and clinical studies reported observations correlating aberrant DNA-PK status and activity with cancer onset, progression and responses to therapeutic modalities. Notably, various studies have established in recent years the role of DNA-PK outside the DDR network, corroborating its role as a pleiotropic complex involved in transcriptional programs that operate biologic processes as epithelial to mesenchymal transition (EMT), hypoxia, metabolism, nuclear receptors signaling and inflammatory responses. In particular tumor entities as prostate cancer, immense research efforts assisted mapping and describing the overall signaling networks regulated by DNA-PK that control metastasis and tumor progression. Correspondingly, DNA-PK emerges as an obvious therapeutic target in cancer and data pertaining to various pharmacological approaches have been published, largely in context of combination with DNA-damaging agents (DDAs) that act by inflicting DNA double strand breaks (DSBs). Currently, new generation inhibitors are tested in clinical trials. Several excellent reviews have been published in recent years covering the biology of DNA-PK and its role in cancer. In the current article we are aiming to systematically describe the main findings on DNA-PK signaling in major cancer types, focusing on both preclinical and clinical reports and present a detailed current status of the DNA-PK inhibitors repertoire.
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14
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Wang XS, Lee BJ, Zha S. The recent advances in non-homologous end-joining through the lens of lymphocyte development. DNA Repair (Amst) 2020; 94:102874. [PMID: 32623318 DOI: 10.1016/j.dnarep.2020.102874] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/16/2020] [Accepted: 05/24/2020] [Indexed: 12/17/2022]
Abstract
Lymphocyte development requires ordered assembly and subsequent modifications of the antigen receptor genes through V(D)J recombination and Immunoglobulin class switch recombination (CSR), respectively. While the programmed DNA cleavage events are initiated by lymphocyte-specific factors, the resulting DNA double-strand break (DSB) intermediates activate the ATM kinase-mediated DNA damage response (DDR) and rely on the ubiquitously expressed classical non-homologous end-joining (cNHEJ) pathway including the DNA-dependent protein kinase (DNA-PK), and, in the case of CSR, also the alternative end-joining (Alt-EJ) pathway, for repair. Correspondingly, patients and animal models with cNHEJ or DDR defects develop distinct types of immunodeficiency reflecting their specific DNA repair deficiency. The unique end-structure, sequence context, and cell cycle regulation of V(D)J recombination and CSR also provide a valuable platform to study the mechanisms of, and the interplay between, cNHEJ and DDR. Here, we compare and contrast the genetic consequences of DNA repair defects in V(D)J recombination and CSR with a focus on the newly discovered cNHEJ factors and the kinase-dependent structural roles of ATM and DNA-PK in animal models. Throughout, we try to highlight the pending questions and emerging differences that will extend our understanding of cNHEJ and DDR in the context of primary immunodeficiency and lymphoid malignancies.
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Affiliation(s)
- Xiaobin S Wang
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Graduate Program of Pathobiology and Molecular Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Brian J Lee
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States
| | - Shan Zha
- Institute for Cancer Genetics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States; Department of Immunology and Microbiology, Vagelos College of Physicians and Surgeons, Columbia University, New York City, NY 10032, United States.
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15
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Induction of recurrent break cluster genes in neural progenitor cells differentiated from embryonic stem cells in culture. Proc Natl Acad Sci U S A 2020; 117:10541-10546. [PMID: 32332169 DOI: 10.1073/pnas.1922299117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mild replication stress enhances appearance of dozens of robust recurrent genomic break clusters, termed RDCs, in cultured primary mouse neural stem and progenitor cells (NSPCs). Robust RDCs occur within genes ("RDC-genes") that are long and have roles in neural cell communications and/or have been implicated in neuropsychiatric diseases or cancer. We sought to develop an in vitro approach to determine whether specific RDC formation is associated with neural development. For this purpose, we adapted a system to induce neural progenitor cell (NPC) development from mouse embryonic stem cell (ESC) lines deficient for XRCC4 plus p53, a genotype that enhances DNA double-strand break (DSB) persistence to enhance detection. We tested for RDCs by our genome-wide DSB identification approach that captures DSBs via their ability to join to specific genomic Cas9/single-guide RNA-generated bait DSBs. In XRCC4/p53-deficient ESCs, we detected seven RDCs, all of which were in genes and two of which were robust. In contrast, in NPCs derived from these ESC lines we detected 29 RDCs, a large fraction of which were robust and associated with long, transcribed neural genes that were also robust RDC-genes in primary NSPCs. These studies suggest that many RDCs present in NSPCs are developmentally influenced to occur in this cell type and indicate that induced development of NPCs from ESCs provides an approach to rapidly elucidate mechanistic aspects of NPC RDC formation.
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16
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Chu SH, Chabon JR, Matovina CN, Minehart JC, Chen BR, Zhang J, Kumar V, Xiong Y, Callen E, Hung PJ, Feng Z, Koche RP, Liu XS, Chaudhuri J, Nussenzweig A, Sleckman BP, Armstrong SA. Loss of H3K36 Methyltransferase SETD2 Impairs V(D)J Recombination during Lymphoid Development. iScience 2020; 23:100941. [PMID: 32169821 PMCID: PMC7066224 DOI: 10.1016/j.isci.2020.100941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/25/2020] [Accepted: 02/21/2020] [Indexed: 12/17/2022] Open
Abstract
Repair of DNA double-stranded breaks (DSBs) during lymphocyte development is essential for V(D)J recombination and forms the basis of immunoglobulin variable region diversity. Understanding of this process in lymphogenesis has historically been centered on the study of RAG1/2 recombinases and a set of classical non-homologous end-joining factors. Much less has been reported regarding the role of chromatin modifications on this process. Here, we show a role for the non-redundant histone H3 lysine methyltransferase, Setd2, and its modification of lysine-36 trimethylation (H3K36me3), in the processing and joining of DNA ends during V(D)J recombination. Loss leads to mis-repair of Rag-induced DNA DSBs, especially when combined with loss of Atm kinase activity. Furthermore, loss reduces immune repertoire and a severe block in lymphogenesis as well as causes post-mitotic neuronal apoptosis. Together, these studies are suggestive of an important role of Setd2/H3K36me3 in these two mammalian developmental processes that are influenced by double-stranded break repair.
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Affiliation(s)
- S Haihua Chu
- Department of Pediatric Oncology, Dana Farber Cancer Institute, and Division of Hematology/Oncology, Boston Children's Hospital, 450 Brookline Avenue, Boston, MA 02215-5450, USA
| | - Jonathan R Chabon
- Department of Pediatric Oncology, Dana Farber Cancer Institute, and Division of Hematology/Oncology, Boston Children's Hospital, 450 Brookline Avenue, Boston, MA 02215-5450, USA
| | - Chloe N Matovina
- Department of Pediatric Oncology, Dana Farber Cancer Institute, and Division of Hematology/Oncology, Boston Children's Hospital, 450 Brookline Avenue, Boston, MA 02215-5450, USA
| | | | - Bo-Ruei Chen
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Jian Zhang
- Center for Computational Biology, Beijing Institute of Basic Medical Sciences, Beijing, China; Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Vipul Kumar
- Howard Hughes Medical Institute, Department of Pediatrics, Department of Genetics, Harvard Medical School, Boston, MA, USA; Harvard-MIT MD-PhD Program, Harvard Medical School, Boston, MA, USA
| | - Yijun Xiong
- Department of Pediatric Oncology, Dana Farber Cancer Institute, and Division of Hematology/Oncology, Boston Children's Hospital, 450 Brookline Avenue, Boston, MA 02215-5450, USA
| | - Elsa Callen
- Laboratory of Genome Integrity, National Cancer Institute National Institutes of Health, Bethesda, MD, USA
| | - Putzer J Hung
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Zhaohui Feng
- Department of Pediatric Oncology, Dana Farber Cancer Institute, and Division of Hematology/Oncology, Boston Children's Hospital, 450 Brookline Avenue, Boston, MA 02215-5450, USA
| | - Richard P Koche
- Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - X Shirley Liu
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute and Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Jayanta Chaudhuri
- Immunology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Immunology and Microbial Pathogenesis Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA
| | - Andre Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute National Institutes of Health, Bethesda, MD, USA
| | - Barry P Sleckman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Scott A Armstrong
- Department of Pediatric Oncology, Dana Farber Cancer Institute, and Division of Hematology/Oncology, Boston Children's Hospital, 450 Brookline Avenue, Boston, MA 02215-5450, USA.
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17
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OKAWA A, MORIOKA T, IMAOKA T, KAKINUMA S, MATSUMOTO Y. Differential expression of DNA-dependent protein kinase catalytic subunit in the brain of neonatal mice and young adult mice. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2020; 96:171-179. [PMID: 32389917 PMCID: PMC7248211 DOI: 10.2183/pjab.96.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 03/10/2020] [Indexed: 06/11/2023]
Abstract
It is generally thought that younger people are more susceptible to cancer development after exposure to ionizing radiation in reference to epidemiological studies and animal experiments. However, little is known about the age-dependent alteration in DNA repair ability. In the present study, we examined the expression levels of proteins involved in the repair of DNA double-strand breaks through non-homologous end joining (NHEJ), i.e., DNA-dependent protein kinase catalytic subunit (DNA-PKcs), X-ray repair cross-complementing 4 (XRCC4) and XRCC4-like factor (XLF). We found that the expression of DNA-PKcs in brain tissues was higher in neonatal mice (1 week after birth) than in young adult mice (7 weeks after birth). In association with this, DNA double-strand breaks were repaired more rapidly in the brain tissues of neonatal mice than in those of young adult mice. The current results suggested a possible role for DNA-PKcs protecting developing brain tissues from DNA double-strand breaks.
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Affiliation(s)
- Aoi OKAWA
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
| | - Takamitsu MORIOKA
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tatsuhiko IMAOKA
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Shizuko KAKINUMA
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Yoshihisa MATSUMOTO
- Laboratory for Advanced Nuclear Energy, Institute of Innovative Research, Tokyo Institute of Technology, Tokyo, Japan
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18
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Beck C, Castañeda-Zegarra S, Huse C, Xing M, Oksenych V. Mediator of DNA Damage Checkpoint Protein 1 Facilitates V(D)J Recombination in Cells Lacking DNA Repair Factor XLF. Biomolecules 2019; 10:biom10010060. [PMID: 31905950 PMCID: PMC7023129 DOI: 10.3390/biom10010060] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 11/16/2022] Open
Abstract
DNA double-strand breaks (DSBs) trigger the Ataxia telangiectasia mutated (ATM)-dependent DNA damage response (DDR), which consists of histone H2AX, MDC1, RNF168, 53BP1, PTIP, RIF1, Rev7, and Shieldin. Early stages of B and T lymphocyte development are dependent on recombination activating gene (RAG)-induced DSBs that form the basis for further V(D)J recombination. Non-homologous end joining (NHEJ) pathway factors recognize, process, and ligate DSBs. Based on numerous loss-of-function studies, DDR factors were thought to be dispensable for the V(D)J recombination. In particular, mice lacking Mediator of DNA Damage Checkpoint Protein 1 (MDC1) possessed nearly wild-type levels of mature B and T lymphocytes in the spleen, thymus, and bone marrow. NHEJ factor XRCC4-like factor (XLF)/Cernunnos is functionally redundant with ATM, histone H2AX, and p53-binding protein 1 (53BP1) during the lymphocyte development in mice. Here, we genetically inactivated MDC1, XLF, or both MDC1 and XLF in murine vAbl pro-B cell lines and, using chromosomally integrated substrates, demonstrated that MDC1 stimulates the V(D)J recombination in cells lacking XLF. Moreover, combined inactivation of MDC1 and XLF in mice resulted in synthetic lethality. Together, these findings suggest that MDC1 and XLF are functionally redundant during the mouse development, in general, and the V(D)J recombination, in particular.
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Affiliation(s)
- Carole Beck
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
| | - Sergio Castañeda-Zegarra
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
| | - Camilla Huse
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
| | - Mengtan Xing
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
| | - Valentyn Oksenych
- Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway
- Department of Biosciences and Nutrition (BioNuT), Karolinska Institutet, 14183 Huddinge, Sweden
- Correspondence:
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19
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Roussel MF, Stripay JL. Modeling pediatric medulloblastoma. Brain Pathol 2019; 30:703-712. [PMID: 31788908 PMCID: PMC7317774 DOI: 10.1111/bpa.12803] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 11/17/2019] [Indexed: 12/15/2022] Open
Abstract
Mouse models of medulloblastoma have proven to be instrumental in understanding disease mechanisms, particularly the role of epigenetic and molecular drivers, and establishing appropriate preclinical pipelines. To date, our research community has developed murine models for all four groups of medulloblastoma, each of which will be critical for the identification and development of new therapeutic approaches. Approaches to modeling medulloblastoma range from genetic engineering with CRISPR/Cas9 or in utero electroporation, to orthotopic and patient‐derived orthotopic xenograft systems. Each approach or model presents unique advantages that have ultimately contributed to an appreciation of medulloblastoma heterogeneity and the clinical obstacles that exist for this patient population.
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Affiliation(s)
- Martine F Roussel
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105
| | - Jennifer L Stripay
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105
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20
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Li W, Bai X, Li J, Zhao Y, Liu J, Zhao H, Liu L, Ding M, Wang Q, Shi FY, Hou M, Ji J, Gao G, Guo R, Sun Y, Liu Y, Xu D. The nucleoskeleton protein IFFO1 immobilizes broken DNA and suppresses chromosome translocation during tumorigenesis. Nat Cell Biol 2019; 21:1273-1285. [DOI: 10.1038/s41556-019-0388-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/09/2019] [Indexed: 01/19/2023]
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21
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DNA damage in aging, the stem cell perspective. Hum Genet 2019; 139:309-331. [PMID: 31324975 DOI: 10.1007/s00439-019-02047-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/05/2019] [Indexed: 02/07/2023]
Abstract
DNA damage is one of the most consistent cellular process proposed to contribute to aging. The maintenance of genomic and epigenomic integrity is critical for proper function of cells and tissues throughout life, and this homeostasis is under constant strain from both extrinsic and intrinsic insults. Considering the relationship between lifespan and genotoxic burden, it is plausible that the longest-lived cellular populations would face an accumulation of DNA damage over time. Tissue-specific stem cells are multipotent populations residing in localized niches and are responsible for maintaining all lineages of their resident tissue/system throughout life. However, many of these stem cells are impacted by genotoxic stress. Several factors may dictate the specific stem cell population response to DNA damage, including the niche location, life history, and fate decisions after damage accrual. This leads to differential handling of DNA damage in different stem cell compartments. Given the importance of adult stem cells in preserving normal tissue function during an individual's lifetime, DNA damage sensitivity and accumulation in these compartments could have crucial implications for aging. Despite this, more support for direct functional effects driven by accumulated DNA damage in adult stem cell compartments is needed. This review will present current evidence for the accumulation and potential influence of DNA damage in adult tissue-specific stem cells and propose inquiry directions that could benefit individual healthspan.
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22
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Kurtz P, Jones AE, Tiwari B, Link N, Wylie A, Tracy C, Krämer H, Abrams JM. Drosophila p53 directs nonapoptotic programs in postmitotic tissue. Mol Biol Cell 2019; 30:1339-1351. [PMID: 30892991 PMCID: PMC6724604 DOI: 10.1091/mbc.e18-12-0791] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
TP53 is the most frequently mutated gene in human cancers, and despite intensive research efforts, genome-scale studies of p53 function in whole animal models are rare. The need for such in vivo studies is underscored by recent challenges to established paradigms, indicating that unappreciated p53 functions contribute to cancer prevention. Here we leveraged the Drosophila system to interrogate p53 function in a postmitotic context. In the developing embryo, p53 robustly activates important apoptotic genes in response to radiation-induced DNA damage. We recently showed that a p53 enhancer (p53RErpr) near the cell death gene reaper forms chromatin contacts and enables p53 target activation across long genomic distances. Interestingly, we found that this canonical p53 apoptotic program fails to activate in adult heads. Moreover, this failure to exhibit apoptotic responses was not associated with altered chromatin contacts. Instead, we determined that p53 does not occupy the p53RErpr enhancer in this postmitotic tissue as it does in embryos. Through comparative RNA-seq and chromatin immunoprecipitation-seq studies of developing and postmitotic tissues, we further determined that p53 regulates distinct transcriptional programs in adult heads, including DNA repair, metabolism, and proteolysis genes. Strikingly, in the postmitotic context, p53-binding landscapes were poorly correlated with nearby transcriptional effects, raising the possibility that p53 enhancers could be generally acting through long distances.
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Affiliation(s)
- Paula Kurtz
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Amanda E Jones
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Bhavana Tiwari
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Nichole Link
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030.,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030.,Jan and Dan Duncan Neurological Research Institute, Houston, TX 77030
| | - Annika Wylie
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Charles Tracy
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Helmut Krämer
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - John M Abrams
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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23
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Cancer risk from low dose radiation in Ptch1/ mice with inactive DNA repair systems: Therapeutic implications for medulloblastoma. DNA Repair (Amst) 2019; 74:70-79. [DOI: 10.1016/j.dnarep.2018.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/03/2018] [Accepted: 12/14/2018] [Indexed: 12/14/2022]
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24
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Ratnaparkhe M, Wong JKL, Wei PC, Hlevnjak M, Kolb T, Simovic M, Haag D, Paul Y, Devens F, Northcott P, Jones DTW, Kool M, Jauch A, Pastorczak A, Mlynarski W, Korshunov A, Kumar R, Downing SM, Pfister SM, Zapatka M, McKinnon PJ, Alt FW, Lichter P, Ernst A. Defective DNA damage repair leads to frequent catastrophic genomic events in murine and human tumors. Nat Commun 2018; 9:4760. [PMID: 30420702 PMCID: PMC6232171 DOI: 10.1038/s41467-018-06925-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 10/08/2018] [Indexed: 12/22/2022] Open
Abstract
Chromothripsis and chromoanasynthesis are catastrophic events leading to clustered genomic rearrangements. Whole-genome sequencing revealed frequent complex genomic rearrangements (n = 16/26) in brain tumors developing in mice deficient for factors involved in homologous-recombination-repair or non-homologous-end-joining. Catastrophic events were tightly linked to Myc/Mycn amplification, with increased DNA damage and inefficient apoptotic response already observable at early postnatal stages. Inhibition of repair processes and comparison of the mouse tumors with human medulloblastomas (n = 68) and glioblastomas (n = 32) identified chromothripsis as associated with MYC/MYCN gains and with DNA repair deficiencies, pointing towards therapeutic opportunities to target DNA repair defects in tumors with complex genomic rearrangements. Chromothripsis and chromoanasynthesis lead to locally clustered rearrangements affecting one or a few chromosomes, but their impact on cancer development and progression is unclear. Here the authors analyse the role of DNA repair factors in brain tumors by whole-genome sequencing of tumors from mouse models of medulloblastoma or high grade gliomas.
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Affiliation(s)
- Manasi Ratnaparkhe
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ); Faculty of Biosciences, Heidelberg University Germany, Heidelberg, 69120, Germany
| | - John K L Wong
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Pei-Chi Wei
- Boston Children's Hospital, Howard Hughes Medical Institute and Department of Genetics, Harvard Medical School, Boston, 02115, MA, USA
| | - Mario Hlevnjak
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Thorsten Kolb
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Milena Simovic
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ); Faculty of Biosciences, Heidelberg University Germany, Heidelberg, 69120, Germany
| | - Daniel Haag
- Hopp Children's Cancer Center at the NCT Heidelberg (KiTZ), Heidelberg, 69120, Germany
| | - Yashna Paul
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Frauke Devens
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Paul Northcott
- Division of Pediatric Neurooncology, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.,Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105-3678, United States
| | - David T W Jones
- Hopp Children's Cancer Center at the NCT Heidelberg (KiTZ), Heidelberg, 69120, Germany
| | - Marcel Kool
- Hopp Children's Cancer Center at the NCT Heidelberg (KiTZ), Heidelberg, 69120, Germany
| | - Anna Jauch
- Institute of Human Genetics, University of Heidelberg, Heidelberg, 69120, Germany
| | - Agata Pastorczak
- Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, 91-738, Poland
| | - Wojciech Mlynarski
- Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, 91-738, Poland
| | - Andrey Korshunov
- Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Department of Neuropathology, Heidelberg University Hospital and German Cancer Consortium (DKTK), Heidelberg, 69120, Germany
| | - Rajiv Kumar
- Division of Molecular Genetic Epidemiology; German Consortium for Translational Cancer Research (DKTK), German Cancer Research Center, Heidelberg, 69120, Germany
| | - Susanna M Downing
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, 38105-3678, TN, USA
| | - Stefan M Pfister
- Hopp Children's Cancer Center at the NCT Heidelberg (KiTZ), Heidelberg, 69120, Germany
| | - Marc Zapatka
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Peter J McKinnon
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, 38105-3678, TN, USA
| | - Frederick W Alt
- Boston Children's Hospital, Howard Hughes Medical Institute and Department of Genetics, Harvard Medical School, Boston, 02115, MA, USA
| | - Peter Lichter
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany
| | - Aurélie Ernst
- Division of Molecular Genetics, German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany.
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Kim J, Kim J, Lee Y. DNA polymerase β deficiency in the p53 null cerebellum leads to medulloblastoma formation. Biochem Biophys Res Commun 2018; 505:548-553. [PMID: 30274781 DOI: 10.1016/j.bbrc.2018.09.166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 09/26/2018] [Indexed: 10/28/2022]
Abstract
Defects in DNA damage response or repair mechanisms during neurogenesis result in genomic instability, which is causative for several neural defects. These include brain tumors, particularly medulloblastoma, which occurs in the cerebellum with a high incidence in children. We generated an animal model with defective base excision repair during brain development through selective inactivation of DNA polymerase β (Polb) in neuroprogenitor cells. All of Polb conditional knockout mice developed medulloblastoma in a p53 null background, similar to the Xrcc1 and p53 double deficient animal model. XRCC1 is a scaffolding protein which is involved in DNA damage repair and binds to POLB. In both animal models, the histopathological characteristics of the medulloblastoma were similar to those of human classic medulloblastoma. Brain tumor development was slower in the Polb and p53 double null animals than in the Xrcc1 and p53 double knockout animals. Molecular marker analysis suggested that Polb- and Xrcc1-deficient medulloblastomas belonged to the SHHα subtype, underscoring the important role of genomic stability in preventing this devastating pediatric cerebellar tumor.
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Affiliation(s)
- Jusik Kim
- Genomic Instability Research Center, Ajou University School of Medicine, Suwon, Republic of Korea; Department of Biomedical Sciences, The Graduate School, Ajou University, Suwon, Republic of Korea
| | - Jaemi Kim
- Genomic Instability Research Center, Ajou University School of Medicine, Suwon, Republic of Korea; Genome Stability Institute, Ajou University School of Medicine, Suwon, Republic of Korea
| | - Youngsoo Lee
- Genomic Instability Research Center, Ajou University School of Medicine, Suwon, Republic of Korea; Genome Stability Institute, Ajou University School of Medicine, Suwon, Republic of Korea; Department of Biomedical Sciences, The Graduate School, Ajou University, Suwon, Republic of Korea.
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26
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Alt FW, Schwer B. DNA double-strand breaks as drivers of neural genomic change, function, and disease. DNA Repair (Amst) 2018; 71:158-163. [PMID: 30195640 DOI: 10.1016/j.dnarep.2018.08.019] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Early work from about two decades ago implicated DNA double-strand break (DSB) formation and repair in neuronal development. Findings emerging from recent studies of DSBs in proliferating neural progenitors and in mature, non-dividing neurons suggest important roles of DSBs in brain physiology, aging, cancer, psychiatric and neurodegenerative disorders. We provide an overview of some findings and speculate on what may lie ahead.
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Affiliation(s)
- Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, United States.
| | - Bjoern Schwer
- Department of Neurological Surgery and Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94158, United States.
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27
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Willis NA, Panday A, Duffey EE, Scully R. Rad51 recruitment and exclusion of non-homologous end joining during homologous recombination at a Tus/Ter mammalian replication fork barrier. PLoS Genet 2018; 14:e1007486. [PMID: 30024881 PMCID: PMC6067765 DOI: 10.1371/journal.pgen.1007486] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 07/31/2018] [Accepted: 06/13/2018] [Indexed: 11/19/2022] Open
Abstract
Classical non-homologous end joining (C-NHEJ) and homologous recombination (HR) compete to repair mammalian chromosomal double strand breaks (DSBs). However, C-NHEJ has no impact on HR induced by DNA nicking enzymes. In this case, the replication fork is thought to convert the DNA nick into a one-ended DSB, which lacks a readily available partner for C-NHEJ. Whether C-NHEJ competes with HR at a non-enzymatic mammalian replication fork barrier (RFB) remains unknown. We previously showed that conservative "short tract" gene conversion (STGC) induced by a chromosomal Tus/Ter RFB is a product of bidirectional replication fork stalling. This finding raises the possibility that Tus/Ter-induced STGC proceeds via a two-ended DSB intermediate. If so, Tus/Ter-induced STGC might be subject to competition by C-NHEJ. However, in contrast to the DSB response, where genetic ablation of C-NHEJ stimulates HR, we report here that Tus/Ter-induced HR is unaffected by deletion of either of two C-NHEJ genes, Xrcc4 or Ku70. These results show that Tus/Ter-induced HR does not entail the formation of a two-ended DSB to which C-NHEJ has competitive access. We found no evidence that the alternative end-joining factor, DNA polymerase θ, competes with Tus/Ter-induced HR. We used chromatin-immunoprecipitation to compare Rad51 recruitment to a Tus/Ter RFB and to a neighboring site-specific DSB. Rad51 accumulation at Tus/Ter was more intense and more sustained than at a DSB. In contrast to the DSB response, Rad51 accumulation at Tus/Ter was restricted to within a few hundred base pairs of the RFB. Taken together, these findings suggest that the major DNA structures that bind Rad51 at a Tus/Ter RFB are not conventional DSBs. We propose that Rad51 acts as an "early responder" at stalled forks, binding single stranded daughter strand gaps on the arrested lagging strand, and that Rad51-mediated fork remodeling generates HR intermediates that are incapable of Ku binding and therefore invisible to the C-NHEJ machinery.
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Affiliation(s)
- Nicholas A. Willis
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Arvind Panday
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Erin E. Duffey
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Ralph Scully
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
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28
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Li T, Liu X, Jiang L, Manfredi J, Zha S, Gu W. Loss of p53-mediated cell-cycle arrest, senescence and apoptosis promotes genomic instability and premature aging. Oncotarget 2017; 7:11838-49. [PMID: 26943586 PMCID: PMC4914251 DOI: 10.18632/oncotarget.7864] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 02/18/2016] [Indexed: 01/22/2023] Open
Abstract
Although p53-mediated cell cycle arrest, senescence and apoptosis are well accepted as major tumor suppression mechanisms, the loss of these functions does not directly lead to tumorigenesis, suggesting that the precise roles of these canonical activities of p53 need to be redefined. Here, we report that the cells derived from the mutant mice expressing p533KR, an acetylation-defective mutant that fails to induce cell-cycle arrest, senescence and apoptosis, exhibit high levels of aneuploidy upon DNA damage. Moreover, the embryonic lethality caused by the deficiency of XRCC4, a key DNA double strand break repair factor, can be fully rescued in the p533KR/3KR background. Notably, despite high levels of genomic instability, p533KR/3KRXRCC4−/− mice, unlike p53−/− XRCC4−/− mice, are not succumbed to pro-B-cell lymphomas. Nevertheless, p533KR/3KR XRCC4−/− mice display aging-like phenotypes including testicular atrophy, kyphosis, and premature death. Further analyses demonstrate that SLC7A11 is downregulated and that p53-mediated ferroptosis is significantly induced in spleens and testis of p533KR/3KRXRCC4−/− mice. These results demonstrate that the direct role of p53-mediated cell cycle arrest, senescence and apoptosis is to control genomic stability in vivo. Our study not only validates the importance of ferroptosis in p53-mediated tumor suppression in vivo but also reveals that the combination of genomic instability and activation of ferroptosis may promote aging-associated phenotypes.
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Affiliation(s)
- Tongyuan Li
- Institute for Cancer Genetics, and Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Xiangyu Liu
- Institute for Cancer Genetics, and Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Le Jiang
- Institute for Cancer Genetics, and Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - James Manfredi
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Shan Zha
- Institute for Cancer Genetics, and Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Department of Pediatrics, College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Wei Gu
- Institute for Cancer Genetics, and Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA
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29
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Willis NA, Frock RL, Menghi F, Duffey EE, Panday A, Camacho V, Hasty EP, Liu ET, Alt FW, Scully R. Mechanism of tandem duplication formation in BRCA1-mutant cells. Nature 2017; 551:590-595. [PMID: 29168504 PMCID: PMC5728692 DOI: 10.1038/nature24477] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 10/09/2017] [Indexed: 11/16/2022]
Abstract
Small, approximately 10-kilobase microhomology-mediated tandem duplications are abundant in the genomes of BRCA1-linked but not BRCA2-linked breast cancer. Here we define the mechanism underlying this rearrangement signature. We show that, in primary mammalian cells, BRCA1, but not BRCA2, suppresses the formation of tandem duplications at a site-specific chromosomal replication fork barrier imposed by the binding of Tus proteins to an array of Ter sites. BRCA1 has no equivalent role at chromosomal double-stranded DNA breaks, indicating that tandem duplications form specifically at stalled forks. Tandem duplications in BRCA1 mutant cells arise by a replication restart-bypass mechanism terminated by end joining or by microhomology-mediated template switching, the latter forming complex tandem duplication breakpoints. Solitary DNA ends form directly at Tus-Ter, implicating misrepair of these lesions in tandem duplication formation. Furthermore, BRCA1 inactivation is strongly associated with ~10 kilobase tandem duplications in ovarian cancer. This tandem duplicator phenotype may be a general signature of BRCA1-deficient cancer.
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Affiliation(s)
- Nicholas A. Willis
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Richard L. Frock
- Boston Children’s Hospital, Howard Hughes Medical Institute and Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Francesca Menghi
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | - Erin E. Duffey
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Arvind Panday
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Virginia Camacho
- Department of Medicine, Flow Cytometry Core, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - E. Paul Hasty
- The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Edison T. Liu
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
- The Jackson Laboratory, Bar Harbor, Maine, USA
| | - Frederick W. Alt
- Boston Children’s Hospital, Howard Hughes Medical Institute and Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Ralph Scully
- Department of Medicine, Division of Hematology-Oncology and Cancer Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
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30
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Zhao L, Wang B, Zhao X, Wu X, Zhang Q, Wei C, Shi M, Li Y, Tang W, Zhang J, Yang J, Singh SK, Jia S, Luo Y. Gain of function in the mouse model of a recurrent mutation p53 N236S promotes the formation of double minute chromosomes and the oncogenic potential of p19 ARF. Mol Carcinog 2017; 57:147-158. [PMID: 28949402 DOI: 10.1002/mc.22737] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 08/11/2017] [Accepted: 09/05/2017] [Indexed: 01/08/2023]
Abstract
The mutation p53N236S (p53S) has been identified as one of the recurrent mutations in human cancers by TCGA database. Our in vitro data revealed the oncogenic gain of function of p53S. To understand the function of p53S in vivo, we generated the p53S knock-in mouse. The p53S/S mice manifested highly invasive lymphomas and metastatic sarcomas with dramatically increased double minute chromosomes. The survival curve, the incidence of tumors and the tumor spectrum of p53S/S mice is very similar to the p53R172H mouse model. The p53S/+ mice showed delayed onset of tumorigenesis and a high metastasis rate (40%) and low loss of heterozygosity rate (2/16). The activation of CDKN2A pathway in p53S/S MEF and tumors, and the accumulation of p19ARF protein in tumor tissues suggested p19ARF might contribute to the accumulation of mutant p53S protein in the tumor and promote tumorigenesis. The high expression of p19ARF correlated with mutant p53 accumulation and tumor progression, suggesting a dual role of p19ARF in tumor promotion or suppression that might depend on the p53 mutation status in tumor cells. The oncogenic gain of function of this recurrent mutation p53S prompts the reconsideration of p53 mutations function that occurs at a low frequency.
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Affiliation(s)
- Lanjun Zhao
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China.,Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Boyuan Wang
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China.,Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Xilong Zhao
- Department of Pathology, Kunming General Hospital, Kunming, Yunnan Province, China
| | - Xiaoming Wu
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Qiushi Zhang
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Chuanyu Wei
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China.,Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Minling Shi
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Yunlong Li
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Wenru Tang
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Jihong Zhang
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Julun Yang
- Department of Pathology, Kunming General Hospital, Kunming, Yunnan Province, China
| | - Sanjay K Singh
- Department of Diagnostic Radiology, MD Anderson Cancer Center, Houston, Texas
| | - Shuting Jia
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China
| | - Ying Luo
- Lab of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan Province, China.,Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province, China.,Yunnan Provincial Institute of Digestive Disease, Yunnan Province, China
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31
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Xing M, Bjørås M, Daniel JA, Alt FW, Oksenych V. Synthetic lethality between murine DNA repair factors XLF and DNA-PKcs is rescued by inactivation of Ku70. DNA Repair (Amst) 2017; 57:133-138. [PMID: 28759779 PMCID: PMC5584571 DOI: 10.1016/j.dnarep.2017.07.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 06/25/2017] [Accepted: 07/24/2017] [Indexed: 11/18/2022]
Abstract
DNA double-strand breaks (DSBs) are recognized and repaired by the Classical Non-Homologous End-Joining (C-NHEJ) and Homologous Recombination pathways. C-NHEJ includes the core Ku70 and Ku80 (or Ku86) heterodimer that binds DSBs and thus promotes recruitment of accessory downstream NHEJ factors XLF, PAXX, DNA-PKcs, Artemis and other core subunits, XRCC4 and DNA Ligase 4 (Lig4). In the absence of core C-NHEJ factors, DNA repair can be performed by Alternative End-Joining, which likely depends on DNA Ligase 1 and DNA Ligase 3. Genetic inactivation of C-NHEJ factors, such as Ku70, Ku80, XLF, PAXX and DNA-PKcs results in viable mice showing increased levels of genomic instability and sensitivity to DSBs. Knockouts of XRCC4 or Lig4, on the other hand, as well as combined inactivation of XLF and DNA-PKcs, or XLF and PAXX, result in late embryonic lethality in mice, which in most cases correlate with severe apoptosis in the central nervous system. Here, we demonstrate that inactivation of the Ku70 gene rescues the synthetic lethality between XLF and DNA-PKcs, resulting in triple knockout mice that are indistinguishable from Ku70-deficient littermates by size or levels of genomic instability. Moreover, we find that combined inactivation of Ku70 and XLF results in viable mice. Together, these findings suggest that Ku70 is epistatic with XLF and DNA-PKcs and support a model in which inactivation of Ku70 allows DNA lesions to become accessible to alternative DNA repair pathways.
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Affiliation(s)
- Mengtan Xing
- Institute for Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Laboratory Center, Erling Skjalgssons Gate 1, 7491 Trondheim, Norway
| | - Magnar Bjørås
- Institute for Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Laboratory Center, Erling Skjalgssons Gate 1, 7491 Trondheim, Norway
| | - Jeremy A Daniel
- The NNF Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, United States.
| | - Valentyn Oksenych
- Institute for Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Laboratory Center, Erling Skjalgssons Gate 1, 7491 Trondheim, Norway; The NNF Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, United States; St. Olavs Hospital, Trondheim University Hospital, Clinic of Medicine, Postboks 3250 Sluppen, 7006 Trondheim, Norway.
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32
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The Role of the Core Non-Homologous End Joining Factors in Carcinogenesis and Cancer. Cancers (Basel) 2017; 9:cancers9070081. [PMID: 28684677 PMCID: PMC5532617 DOI: 10.3390/cancers9070081] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 06/30/2017] [Accepted: 07/03/2017] [Indexed: 12/20/2022] Open
Abstract
DNA double-strand breaks (DSBs) are deleterious DNA lesions that if left unrepaired or are misrepaired, potentially result in chromosomal aberrations, known drivers of carcinogenesis. Pathways that direct the repair of DSBs are traditionally believed to be guardians of the genome as they protect cells from genomic instability. The prominent DSB repair pathway in human cells is the non-homologous end joining (NHEJ) pathway, which mediates template-independent re-ligation of the broken DNA molecule and is active in all phases of the cell cycle. Its role as a guardian of the genome is supported by the fact that defects in NHEJ lead to increased sensitivity to agents that induce DSBs and an increased frequency of chromosomal aberrations. Conversely, evidence from tumors and tumor cell lines has emerged that NHEJ also promotes chromosomal aberrations and genomic instability, particularly in cells that have a defect in one of the other DSB repair pathways. Collectively, the data present a conundrum: how can a single pathway both suppress and promote carcinogenesis? In this review, we will examine NHEJ's role as both a guardian and a disruptor of the genome and explain how underlying genetic context not only dictates whether NHEJ promotes or suppresses carcinogenesis, but also how it alters the response of tumors to conventional therapeutics.
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33
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McKay MJ, Goh SK, McKay JN, Chao M, McKay TM. Non-homologous end-joining protein expression screen from radiosensitive cancer patients yields a novel DNA double strand break repair phenotype. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:96. [PMID: 28361061 DOI: 10.21037/atm.2017.03.04] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Clinical radiosensitivity is a significant impediment to tumour control and cure, in that it restricts the total doses which can safely be delivered to the whole radiotherapy population, within the tissue tolerance of potentially radiosensitive (RS) individuals. Understanding its causes could lead to personalization of radiotherapy. METHODS We screened tissues from a unique bank of RS cancer patients for expression defects in major DNA double-strand break repair proteins, using Western blot analysis and subsequently reverse-transcriptase polymerase chain reaction and pulsed-field gel electrophoresis. RESULTS We hypothesized that abnormalities in expression of these proteins may explain the radiosensitivity of some of our cancer patients. The cells from one patient showed a reproducibly consistent expression reduction in two complex-forming DNA double-strand break repair protein components (DNA Ligase IV and XRCC4). We also showed a corresponding reduction in both gene products at the mRNA level. Additionally, the mRNA inducibility by ionizing radiation was increased for one of the proteins in the patient's cells. We confirmed the likely functional significance of the non-homologous end-joining (NHEJ) expression abnormalities with a DNA double strand break (DNA DSB) repair assay. CONCLUSIONS We have identified a novel biological phenotype linked to clinical radiosensitivity. This is important in that very few molecular defects are known in human radiotherapy subjects. Such knowledge may contribute to the understanding of radiation response mechanisms in cancer patients and to personalization of radiotherapy.
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Affiliation(s)
- Michael J McKay
- University of Sydney, Department of Medicine, Camperdown, 2050 NSW, Australia
| | - Su Kak Goh
- Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | | | - Michael Chao
- Genesis Cancer Care, Melbourne, 3001 VIC, Australia
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Contribution of classical end-joining to PTEN inactivation in p53-mediated glioblastoma formation and drug-resistant survival. Nat Commun 2017; 8:14013. [PMID: 28094268 PMCID: PMC5247582 DOI: 10.1038/ncomms14013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 11/21/2016] [Indexed: 02/07/2023] Open
Abstract
DNA repair gene defects are found in virtually all human glioblastomas, but the genetic evidence for a direct role remains lacking. Here we demonstrate that combined inactivation of the XRCC4 non-homologous end-joining (NHEJ) DNA repair gene and p53 efficiently induces brain tumours with hallmark characteristics of human proneural/classical glioblastoma. The murine tumours exhibit PTEN loss of function instigated by reduced PTEN mRNA, and increased phosphorylated inactivation and stability as a consequence of aberrantly elevated CK2 provoked by p53 ablation and irrevocably deregulated by NHEJ inactivation. This results in DNA damage-resistant cytoplasmic PTEN and CK2 expression, and the attenuation of DNA repair genes. CK2 inhibition restores PTEN nuclear distribution and DNA repair activities and impairs tumour but not normal cell survival. These observations demonstrate that NHEJ contributes to p53-mediated glioblastoma suppression, and reveal a crucial role for PTEN in the early DNA damage signalling cascade, the inhibition of which promotes tumorigenicity and drug-resistant survival. We know that defects in DNA repair genes are associated with cancer development. Here the authors eliminate XRCC4, a non-homologous end-joining protein, and p53 in the developing brain and find that this causes glioblastoma development as a consequence of reduced PTEN function.
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Recurrently Breaking Genes in Neural Progenitors: Potential Roles of DNA Breaks in Neuronal Function, Degeneration and Cancer. RESEARCH AND PERSPECTIVES IN NEUROSCIENCES 2017. [DOI: 10.1007/978-3-319-60192-2_6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Long Neural Genes Harbor Recurrent DNA Break Clusters in Neural Stem/Progenitor Cells. Cell 2016; 164:644-55. [PMID: 26871630 DOI: 10.1016/j.cell.2015.12.039] [Citation(s) in RCA: 184] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 11/23/2015] [Accepted: 12/21/2015] [Indexed: 12/25/2022]
Abstract
Repair of DNA double-strand breaks (DSBs) by non-homologous end joining is critical for neural development, and brain cells frequently contain somatic genomic variations that might involve DSB intermediates. We now use an unbiased, high-throughput approach to identify genomic regions harboring recurrent DSBs in primary neural stem/progenitor cells (NSPCs). We identify 27 recurrent DSB clusters (RDCs), and remarkably, all occur within gene bodies. Most of these NSPC RDCs were detected only upon mild, aphidicolin-induced replication stress, providing a nucleotide-resolution view of replication-associated genomic fragile sites. The vast majority of RDCs occur in long, transcribed, and late-replicating genes. Moreover, almost 90% of identified RDC-containing genes are involved in synapse function and/or neural cell adhesion, with a substantial fraction also implicated in tumor suppression and/or mental disorders. Our characterization of NSPC RDCs reveals a basis of gene fragility and suggests potential impacts of DNA breaks on neurodevelopment and neural functions.
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Abstract
The mechanisms leading to brain tumor formation are poorly understood. Using Ptch1+/- mice as a medulloblastoma model, sequential mutations were found to shape tumor evolution. Initially, medulloblastoma preneoplastic lesions display loss of heterozygosity of the Ptch1 wild-type allele, an event associated with cell senescence in preneoplasia. Subsequently, p53 mutations lead to senescence evasion and progression from preneoplasia to medulloblastoma. These findings are consistent with a model where high levels of Hedgehog signaling caused by the loss of the tumor suppressor Ptch1 lead to oncogene-induced senescence and drive p53 mutations. Thus, cell senescence is an important characteristic of a subset of SHH medulloblastoma and might explain the acquisition of somatic TP53 mutations in human medulloblastoma. This mode of medulloblastoma formation contrasts with the one characterizing Li-Fraumeni patients with medulloblastoma, where TP53 germ-line mutations cause chromothriptic genomic instability and lead to mutations in Hedgehog signaling genes, which drive medulloblastoma growth. Here we discuss in detail these 2 alternative mechanisms leading to medulloblastoma tumorigenesis.
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Affiliation(s)
- Lukas Tamayo-Orrego
- a Molecular Biology of Neural Development , Institut de Recherches Cliniques de Montréal (IRCM) , Montreal , Quebec , Canada.,b Integrated Program in Neuroscience , McGill University , Montreal , Quebec , Canada
| | - Shannon M Swikert
- a Molecular Biology of Neural Development , Institut de Recherches Cliniques de Montréal (IRCM) , Montreal , Quebec , Canada.,b Integrated Program in Neuroscience , McGill University , Montreal , Quebec , Canada
| | - Frédéric Charron
- a Molecular Biology of Neural Development , Institut de Recherches Cliniques de Montréal (IRCM) , Montreal , Quebec , Canada.,b Integrated Program in Neuroscience , McGill University , Montreal , Quebec , Canada.,c Department of Medicine , University of Montreal , Montreal , Quebec , Canada.,d Division of Experimental Medicine , Department of Medicine, Department of Anatomy and Cell Biology, Department of Biology , McGill University , Quebec , Canada
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Barthelery NJ, Manfredi JJ. Cerebellum Development and Tumorigenesis: A p53-Centric Perspective. Trends Mol Med 2016; 22:404-413. [PMID: 27085812 DOI: 10.1016/j.molmed.2016.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/19/2016] [Accepted: 03/19/2016] [Indexed: 12/30/2022]
Abstract
The p53 protein has been extensively studied for its role in suppressing tumorigenesis, in part through surveillance and maintenance of genomic stability. p53 has been associated with the induction of a variety of cellular outcomes including cell cycle arrest, senescence, and apoptosis. This occurs primarily, but not exclusively, through transcriptional activation of specific target genes. By contrast, the participation of p53 in normal developmental processes has been largely understudied. This review focuses on possible functions of p53 in cerebellar development. It can be argued that a better understanding of such mechanisms will provide needed insight into the genesis of certain embryonic cancers including medulloblastomas, and thus lead to more effective therapies.
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Affiliation(s)
- Nicolas J Barthelery
- Department of Oncological Sciences and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - James J Manfredi
- Department of Oncological Sciences and Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.
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Chow KH, Shin DM, Jenkins MH, Miller EE, Shih DJ, Choi S, Low BE, Philip V, Rybinski B, Bronson RT, Taylor MD, Yun K. Epigenetic states of cells of origin and tumor evolution drive tumor-initiating cell phenotype and tumor heterogeneity. Cancer Res 2014; 74:4864-74. [PMID: 25136069 DOI: 10.1158/0008-5472.can-13-3293] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A central confounding factor in the development of targeted therapies is tumor cell heterogeneity, particularly in tumor-initiating cells (TIC), within clinically identical tumors. Here, we show how activation of the Sonic Hedgehog (SHH) pathway in neural stem and progenitor cells creates a foundation for tumor cell evolution to heterogeneous states that are histologically indistinguishable but molecularly distinct. In spontaneous medulloblastomas that arise in Patched (Ptch)(+/-) mice, we identified three distinct tumor subtypes. Through cell type-specific activation of the SHH pathway in vivo, we determined that different cells of origin evolved in unique ways to generate these subtypes. Moreover, TICs in each subtype had distinct molecular and cellular phenotypes. At the bulk tumor level, the three tumor subtypes could be distinguished by a 465-gene signature and by differential activation levels of the ERK and AKT pathways. Notably, TICs from different subtypes were differentially sensitive to SHH or AKT pathway inhibitors, highlighting new mechanisms of resistance to targeted therapies. In summary, our results show how evolutionary processes act on distinct cells of origin to contribute to tumoral heterogeneity, at both bulk tumor and TIC levels.
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Affiliation(s)
| | - Dong-Mi Shin
- Laboratory of Immunogenetics, NIAID/NIH, Bethesda, Maryland. Department of Food and Nutrition, Seoul National University, Seoul, Korea
| | | | | | - David J Shih
- Division of Neurosurgery, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada
| | | | | | | | | | | | - Michael D Taylor
- Division of Neurosurgery, Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Canada
| | - Kyuson Yun
- The Jackson Laboratory, Bar Harbor, Maine.
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Kumar V, Alt FW, Oksenych V. Reprint of "Functional overlaps between XLF and the ATM-dependent DNA double strand break response". DNA Repair (Amst) 2014; 17:52-63. [PMID: 24767946 DOI: 10.1016/j.dnarep.2014.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/14/2014] [Accepted: 01/24/2014] [Indexed: 02/08/2023]
Abstract
Developing B and T lymphocytes generate programmed DNA double strand breaks (DSBs) during the V(D)J recombination process that assembles exons that encode the antigen-binding variable regions of antibodies. In addition, mature B lymphocytes generate programmed DSBs during the immunoglobulin heavy chain (IgH) class switch recombination (CSR) process that allows expression of different antibody heavy chain constant regions that provide different effector functions. During both V(D)J recombination and CSR, DSB intermediates are sensed by the ATM-dependent DSB response (DSBR) pathway, which also contributes to their joining via classical non-homologous end-joining (C-NHEJ). The precise nature of the interplay between the DSBR and C-NHEJ pathways in the context of DSB repair via C-NHEJ remains under investigation. Recent studies have shown that the XLF C-NHEJ factor has functional redundancy with several members of the ATM-dependent DSBR pathway in C-NHEJ, highlighting unappreciated major roles for both XLF as well as the DSBR in V(D)J recombination, CSR and C-NHEJ in general. In this review, we discuss current knowledge of the mechanisms that contribute to the repair of DSBs generated during B lymphocyte development and activation with a focus on potential functionally redundant roles of XLF and ATM-dependent DSBR factors.
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Affiliation(s)
- Vipul Kumar
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, United States
| | - Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, United States.
| | - Valentyn Oksenych
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, United States.
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Kumar V, Alt FW, Oksenych V. Functional overlaps between XLF and the ATM-dependent DNA double strand break response. DNA Repair (Amst) 2014; 16:11-22. [PMID: 24674624 DOI: 10.1016/j.dnarep.2014.01.010] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/14/2014] [Accepted: 01/24/2014] [Indexed: 11/27/2022]
Abstract
Developing B and T lymphocytes generate programmed DNA double strand breaks (DSBs) during the V(D)J recombination process that assembles exons that encode the antigen-binding variable regions of antibodies. In addition, mature B lymphocytes generate programmed DSBs during the immunoglobulin heavy chain (IgH) class switch recombination (CSR) process that allows expression of different antibody heavy chain constant regions that provide different effector functions. During both V(D)J recombination and CSR, DSB intermediates are sensed by the ATM-dependent DSB response (DSBR) pathway, which also contributes to their joining via classical non-homologous end-joining (C-NHEJ). The precise nature of the interplay between the DSBR and C-NHEJ pathways in the context of DSB repair via C-NHEJ remains under investigation. Recent studies have shown that the XLF C-NHEJ factor has functional redundancy with several members of the ATM-dependent DSBR pathway in C-NHEJ, highlighting unappreciated major roles for both XLF as well as the DSBR in V(D)J recombination, CSR and C-NHEJ in general. In this review, we discuss current knowledge of the mechanisms that contribute to the repair of DSBs generated during B lymphocyte development and activation with a focus on potential functionally redundant roles of XLF and ATM-dependent DSBR factors.
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Affiliation(s)
- Vipul Kumar
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, United States
| | - Frederick W Alt
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, United States.
| | - Valentyn Oksenych
- Howard Hughes Medical Institute, Program in Cellular and Molecular Medicine, Boston Children's Hospital, Department of Genetics, Harvard Medical School, Boston, MA 02115, United States.
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Shalaby T, Fiaschetti G, Nagasawa K, Shin-ya K, Baumgartner M, Grotzer M. G-quadruplexes as potential therapeutic targets for embryonal tumors. Molecules 2013; 18:12500-37. [PMID: 24152672 PMCID: PMC6269990 DOI: 10.3390/molecules181012500] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 09/18/2013] [Accepted: 09/25/2013] [Indexed: 12/27/2022] Open
Abstract
Embryonal tumors include a heterogeneous group of highly malignant neoplasms that primarily affect infants and children and are characterized by a high rate of mortality and treatment-related morbidity, hence improved therapies are clearly needed. G-quadruplexes are special secondary structures adopted in guanine (G)-rich DNA sequences that are often present in biologically important regions, e.g. at the end of telomeres and in the regulatory regions of oncogenes such as MYC. Owing to the significant roles that both telomeres and MYC play in cancer cell biology, G-quadruplexes have been viewed as emerging therapeutic targets in oncology and as tools for novel anticancer drug design. Several compounds that target these structures have shown promising anticancer activity in tumor xenograft models and some of them have entered Phase II clinical trials. In this review we examine approaches to DNA targeted cancer therapy, summarize the recent developments of G-quadruplex ligands as anticancer drugs and speculate on the future direction of such structures as a potential novel therapeutic strategy for embryonal tumors of the nervous system.
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Affiliation(s)
- Tarek Shalaby
- Division of Oncology, University Children's Hospital of Zurich, Zurich 8032, Switzerland.
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Natarajan S, Li Y, Miller EE, Shih DJ, Taylor MD, Stearns TM, Bronson RT, Ackerman SL, Yoon JK, Yun K. Notch1-induced brain tumor models the sonic hedgehog subgroup of human medulloblastoma. Cancer Res 2013; 73:5381-90. [PMID: 23852537 DOI: 10.1158/0008-5472.can-13-0033] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
While activation of the Notch pathway is observed in many human cancers, it is unknown whether elevated Notch1 expression is sufficient to initiate tumorigenesis in most tissues. To test the oncogenic potential of Notch1 in solid tumors, we expressed an activated form of Notch1 (N1ICD) in the developing mouse brain. N1ICD;hGFAP-cre mice were viable but developed severe ataxia and seizures, and died by weaning age. Analysis of transgenic embryo brains revealed that N1ICD expression induced p53-dependent apoptosis. When apoptosis was blocked by genetic deletion of p53, 30% to 40% of N1ICD;GFAP-cre;p53(+/-) and N1ICD;GFAP-cre;p53(-/-) mice developed spontaneous medulloblastomas. Interestingly, N1ICD-induced medulloblastomas most closely resembled the sonic hedgehog subgroup of human medulloblastoma at the molecular level. Surprisingly, N1ICD-induced tumors do not maintain high levels of the Notch pathway gene expression, except for Notch2, showing that initiating oncogenic events may not be decipherable by analyzing growing tumors in some cases. In summary, this study shows that Notch1 has an oncogenic potential in the brain when combined with other oncogenic hits, such as p53 loss, and provides a novel mouse model of medulloblastoma. Cancer Res; 73(17); 5381-90. ©2013 AACR.
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44
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Rommel PC, Bosque D, Gitlin AD, Croft GF, Heintz N, Casellas R, Nussenzweig MC, Kriaucionis S, Robbiani DF. Fate mapping for activation-induced cytidine deaminase (AID) marks non-lymphoid cells during mouse development. PLoS One 2013; 8:e69208. [PMID: 23861962 PMCID: PMC3704518 DOI: 10.1371/journal.pone.0069208] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 06/05/2013] [Indexed: 11/18/2022] Open
Abstract
The Aicda gene encodes Activation-Induced cytidine Deaminase (AID), an enzyme essential for remodeling antibody genes in mature B lymphocytes. AID is also responsible for DNA damage at oncogenes, leading to their mutation and cancer-associated chromosome translocation in lymphoma. We used fate mapping and AIDGFP reporter mice to determine if AID expression in the mouse extends beyond lymphocytes. We discovered that AIDcre tags a small fraction of non-lymphoid cells starting at 10.5 days post conception (dpc), and that AIDGFP+ cells are detectable at dpc 11.5 and 12.5. Embryonic cells are tagged by AIDcre in the submandibular region, where conditional deletion of the tumor suppressor PTEN causes squamous papillomas. AIDcre also tags non-lymphoid cells in the embryonic central nervous system. Finally, in the adult mouse brain, AIDcre marks a small fraction of diverse neurons and distinct neuronal populations, including pyramidal cells in cortical layer IV.
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Affiliation(s)
- Philipp C. Rommel
- Laboratory of Molecular Immunology, the Rockefeller University, New York, New York, United States of America
| | - David Bosque
- Laboratory of Molecular Immunology, the Rockefeller University, New York, New York, United States of America
| | - Alexander D. Gitlin
- Laboratory of Molecular Immunology, the Rockefeller University, New York, New York, United States of America
| | - Gist F. Croft
- Laboratory of Molecular Vertebrate Embryology, The Rockefeller University, New York, New York, United States of America
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, The Rockefeller University, New York, New York, United States of America
- Howard Hughes Medical Institute, The Rockefeller University, New York, New York, United States of America
| | - Rafael Casellas
- Genomics and Immunity, NIAMS, and Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Michel C. Nussenzweig
- Laboratory of Molecular Immunology, the Rockefeller University, New York, New York, United States of America
- Howard Hughes Medical Institute, The Rockefeller University, New York, New York, United States of America
| | - Skirmantas Kriaucionis
- Laboratory of Molecular Biology, The Rockefeller University, New York, New York, United States of America
- Ludwig Institute for Cancer Research and University of Oxford, Oxford, United Kingdom
| | - Davide F. Robbiani
- Laboratory of Molecular Immunology, the Rockefeller University, New York, New York, United States of America
- * E-mail:
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Abstract
Glioma and medulloblastoma represent the most commonly occurring malignant brain tumors in adults and in children, respectively. Recent genomic and transcriptional approaches present a complex group of diseases and delineate a number of molecular subgroups within tumors that share a common histopathology. Differences in cells of origin, regional niches, developmental timing, and genetic events all contribute to this heterogeneity. In an attempt to recapitulate the diversity of brain tumors, an increasing array of genetically engineered mouse models (GEMMs) has been developed. These models often utilize promoters and genetic drivers from normal brain development and can provide insight into specific cells from which these tumors originate. GEMMs show promise in both developmental biology and developmental therapeutics. This review describes numerous murine brain tumor models in the context of normal brain development and the potential for these animals to impact brain tumor research.
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Affiliation(s)
- Fredrik J. Swartling
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, SE-75185, Sweden
| | - Sanna-Maria Hede
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, SE-75185, Sweden
| | - William A. Weiss
- University of California, Depts. of Neurology, Pathology, Pediatrics, Neurosurgery, Brain Tumor Research Center and Helen Diller Family Comprehensive Cancer Center, San Francisco CA 94158, USA
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Zhao P, Zou P, Zhao L, Yan W, Kang C, Jiang T, You Y. Genetic polymorphisms of DNA double-strand break repair pathway genes and glioma susceptibility. BMC Cancer 2013; 13:234. [PMID: 23663450 PMCID: PMC3655843 DOI: 10.1186/1471-2407-13-234] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Accepted: 05/03/2013] [Indexed: 11/10/2022] Open
Abstract
Background Genetic variations in DNA double-strand break repair genes can influence the ability of a cell to repair damaged DNA and alter an individual’s susceptibility to cancer. We studied whether polymorphisms in DNA double-strand break repair genes are associated with an increased risk of glioma development. Methods We genotyped 10 potentially functional single nucleotide polymorphisms (SNPs) in 7 DNA double-strand break repair pathway genes (XRCC3, BRCA2, RAG1, XRCC5, LIG4, XRCC4 and ATM) in a case–control study including 384 glioma patients and 384 cancer-free controls in a Chinese Han population. Genotypes were determined using the OpenArray platform. Results In the single-locus analysis there was a significant association between gliomas and the LIG4 rs1805388 (Ex2 +54C>T, Thr9Ile) TT genotype (adjusted OR, 3.27; 95% CI, 1.87-5.71), as well as the TC genotype (adjusted OR, 1.62; 95% CI, 1.20-2.18). We also found that the homozygous variant genotype (GG) of XRCC4 rs1805377 (IVS7-1A>G, splice-site) was associated with a significantly increased risk of gliomas (OR, 1.77; 95% CI, 1.12-2.80). Interestingly, we detected a significant additive and multiplicative interaction effect between the LIG4 rs1805388 and XRCC4 rs1805377 polymorphisms with an increasing risk of gliomas. When we stratified our analysis by smoking status, LIG4 rs1805388 was associated with an increased glioma risk among smokers. Conclusions These results indicate for the first time that LIG4 rs1805388 and XRCC4 rs1805377, alone or in combination, are associated with a risk of gliomas.
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Affiliation(s)
- Peng Zhao
- Department of Neurosurgery, the First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China.
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47
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Wu X, Northcott PA, Croul S, Taylor MD. Mouse models of medulloblastoma. CHINESE JOURNAL OF CANCER 2013; 30:442-9. [PMID: 21718590 PMCID: PMC4013419 DOI: 10.5732/cjc.011.10040] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Medulloblastoma is the most common malignant pediatric brain tumor. Despite its prevalence and importance in pediatric neuro-oncology, the genes and pathways responsible for its initiation, maintenance, and progression remain poorly understood. Genetically engineered mouse models are an essential tool for uncovering the molecular and cellular basis of human diseases, including cancer, and serve a valuable role as preclinical models for testing targeted therapies. In this review, we summarize how such models have been successfully applied to the study of medulloblastoma over the past decade and what we might expect in the coming years.
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Affiliation(s)
- Xiaochong Wu
- Arthur and Sonia Labatt Brain Tumor Research Center, Hospital for Sick Children, Toronto, Ontario, M5G 1L7, Canada
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48
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Functional redundancy between the XLF and DNA-PKcs DNA repair factors in V(D)J recombination and nonhomologous DNA end joining. Proc Natl Acad Sci U S A 2013; 110:2234-9. [PMID: 23345432 DOI: 10.1073/pnas.1222573110] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Classical nonhomologous end joining (C-NHEJ) is a major mammalian DNA double-strand break (DSB) repair pathway that is required for assembly of antigen receptor variable region gene segments by V(D)J recombination. Recombination activating gene endonuclease initiates V(D)J recombination by generating DSBs between two V(D)J coding gene segments and flanking recombination signal sequences (RS), with the two coding ends and two RS ends joined by C-NHEJ to form coding joins and signal joins, respectively. During C-NHEJ, recombination activating gene factor generates two coding ends as covalently sealed hairpins and RS ends as blunt 5'-phosphorylated DSBs. Opening and processing of coding end hairpins before joining by C-NHEJ requires the DNA-dependent protein kinase catalytic subunit (DNA-PKcs). However, C-NHEJ of RS ends, which do not require processing, occurs relatively normally in the absence of DNA-PKcs. The XRCC4-like factor (XLF) is a C-NHEJ component that is not required for C-NHEJ of chromosomal signal joins or coding joins because of functional redundancy with ataxia telangiectasia mutated kinase, a protein that also has some functional overlap with DNA-PKcs in this process. Here, we show that XLF has dramatic functional redundancy with DNA-PKcs in the V(D)J SJ joining process, which is nearly abrogated in their combined absence. Moreover, we show that XLF functionally overlaps with DNA-PKcs in normal mouse development, promotion of genomic stability in mouse fibroblasts, and in IgH class switch recombination in mature B cells. Our findings suggest that DNA-PKcs has fundamental roles in C-NHEJ processes beyond end processing that have been masked by functional overlaps with XLF.
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49
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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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50
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Cell cycle- and DNA repair pathway-specific effects of apoptosis on tumor suppression. Proc Natl Acad Sci U S A 2012; 109:9953-8. [PMID: 22670056 DOI: 10.1073/pnas.1120476109] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The DNA damage response comprises DNA repair, cell-cycle checkpoint control, and DNA damage-induced apoptosis that collectively promote genomic integrity and suppress tumorigenesis. Previously, we have shown that the Chk2 kinase functions independently of the Mre11 complex (Mre11, Rad50, and Nbs1) and ATM in apoptosis and suppresses tumorigenesis resulting from hypomorphic alleles of Mre11 or Nbs1. Based on this work, we have proposed that Chk2 limits the oncogenic potential of replication-associated DNA damage. Here we further address the role of Chk2 and damage-induced apoptosis in suppressing the oncogenic potential of chromosome breaks. We show that loss of Chk2 or a mutation in p53 (R172P), which selectively impairs its function in apoptosis, rescued the lethality of mice lacking Lig4, a ligase required for nonhomologous end-joining (NHEJ) repair of DNA double-strand breaks in G0/G1. In contrast to Lig4(-/-)p53(-/-) mice, Lig4(-/-)Chk2(-/-) and Lig4(-/-)p53(R172P/R172P) mice were not prone to organ-specific, rapid tumorigenesis. Although the severe NHEJ deficiency of Lig4(-/-) was a less potent initiator of tumorigenesis in the p53(R172P/R172P) and Chk2(-/-) backgrounds, where p53 cell-cycle functions are largely intact, even mild defects in the intra-S and G2/M checkpoints caused by mutations in Nbs1 are sufficient to influence malignancy in p53(R172P/R172P) mice. We conclude that the oncogenic potential of double-strand breaks resulting from NHEJ deficiency is highly restricted by nonapoptotic functions of p53, such as the G1/S checkpoint or senescence, suggesting that the particular facets of the DNA damage response required for tumor suppression are dictated by the proliferative status of the tumor-initiating cell.
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