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Wright SE, Todd PK. Native functions of short tandem repeats. eLife 2023; 12:e84043. [PMID: 36940239 PMCID: PMC10027321 DOI: 10.7554/elife.84043] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 03/08/2023] [Indexed: 03/21/2023] Open
Abstract
Over a third of the human genome is comprised of repetitive sequences, including more than a million short tandem repeats (STRs). While studies of the pathologic consequences of repeat expansions that cause syndromic human diseases are extensive, the potential native functions of STRs are often ignored. Here, we summarize a growing body of research into the normal biological functions for repetitive elements across the genome, with a particular focus on the roles of STRs in regulating gene expression. We propose reconceptualizing the pathogenic consequences of repeat expansions as aberrancies in normal gene regulation. From this altered viewpoint, we predict that future work will reveal broader roles for STRs in neuronal function and as risk alleles for more common human neurological diseases.
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Affiliation(s)
- Shannon E Wright
- Department of Neurology, University of Michigan–Ann ArborAnn ArborUnited States
- Neuroscience Graduate Program, University of Michigan–Ann ArborAnn ArborUnited States
- Department of Neuroscience, Picower InstituteCambridgeUnited States
| | - Peter K Todd
- Department of Neurology, University of Michigan–Ann ArborAnn ArborUnited States
- VA Ann Arbor Healthcare SystemAnn ArborUnited States
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Mirceta M, Shum N, Schmidt MHM, Pearson CE. Fragile sites, chromosomal lesions, tandem repeats, and disease. Front Genet 2022; 13:985975. [PMID: 36468036 PMCID: PMC9714581 DOI: 10.3389/fgene.2022.985975] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/02/2022] [Indexed: 09/16/2023] Open
Abstract
Expanded tandem repeat DNAs are associated with various unusual chromosomal lesions, despiralizations, multi-branched inter-chromosomal associations, and fragile sites. Fragile sites cytogenetically manifest as localized gaps or discontinuities in chromosome structure and are an important genetic, biological, and health-related phenomena. Common fragile sites (∼230), present in most individuals, are induced by aphidicolin and can be associated with cancer; of the 27 molecularly-mapped common sites, none are associated with a particular DNA sequence motif. Rare fragile sites ( ≳ 40 known), ≤ 5% of the population (may be as few as a single individual), can be associated with neurodevelopmental disease. All 10 molecularly-mapped folate-sensitive fragile sites, the largest category of rare fragile sites, are caused by gene-specific CGG/CCG tandem repeat expansions that are aberrantly CpG methylated and include FRAXA, FRAXE, FRAXF, FRA2A, FRA7A, FRA10A, FRA11A, FRA11B, FRA12A, and FRA16A. The minisatellite-associated rare fragile sites, FRA10B, FRA16B, can be induced by AT-rich DNA-ligands or nucleotide analogs. Despiralized lesions and multi-branched inter-chromosomal associations at the heterochromatic satellite repeats of chromosomes 1, 9, 16 are inducible by de-methylating agents like 5-azadeoxycytidine and can spontaneously arise in patients with ICF syndrome (Immunodeficiency Centromeric instability and Facial anomalies) with mutations in genes regulating DNA methylation. ICF individuals have hypomethylated satellites I-III, alpha-satellites, and subtelomeric repeats. Ribosomal repeats and subtelomeric D4Z4 megasatellites/macrosatellites, are associated with chromosome location, fragility, and disease. Telomere repeats can also assume fragile sites. Dietary deficiencies of folate or vitamin B12, or drug insults are associated with megaloblastic and/or pernicious anemia, that display chromosomes with fragile sites. The recent discovery of many new tandem repeat expansion loci, with varied repeat motifs, where motif lengths can range from mono-nucleotides to megabase units, could be the molecular cause of new fragile sites, or other chromosomal lesions. This review focuses on repeat-associated fragility, covering their induction, cytogenetics, epigenetics, cell type specificity, genetic instability (repeat instability, micronuclei, deletions/rearrangements, and sister chromatid exchange), unusual heritability, disease association, and penetrance. Understanding tandem repeat-associated chromosomal fragile sites provides insight to chromosome structure, genome packaging, genetic instability, and disease.
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Affiliation(s)
- Mila Mirceta
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Natalie Shum
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Monika H. M. Schmidt
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Christopher E. Pearson
- Program of Genetics and Genome Biology, The Hospital for Sick Children, The Peter Gilgan Centre for Research and Learning, Toronto, ON, Canada
- Program of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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Genomic Organization of Microsatellites and LINE-1-like Retrotransposons: Evolutionary Implications for Ctenomys minutus (Rodentia: Ctenomyidae) Cytotypes. Animals (Basel) 2022; 12:ani12162091. [PMID: 36009681 PMCID: PMC9405301 DOI: 10.3390/ani12162091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/28/2022] [Accepted: 08/13/2022] [Indexed: 12/05/2022] Open
Abstract
Simple Summary In animals, several species contain substantial chromosomal and genomic variation among their populations, but as to what could have driven such diversification is still a puzzle for most cases. Here, we used molecular cytogenetic analysis to expose the main genomic elements involved in the population variation observed in the Neotropical underground rodents of the genus Ctenomys (Rodentia: Ctenomyidae), which harbor the most significant chromosomal variation among mammals (2n = 10 to 2n = 70). These data provide evidence for a correlation between repetitive genomic content and localization of evolutionary breakpoint regions (EBRs) and highlight their direct impact in promoting chromosomal rearrangements. Abstract The Neotropical underground rodents of the genus Ctenomys (Rodentia: Ctenomyidae) comprise about 65 species, which harbor the most significant chromosomal variation among mammals (2n = 10 to 2n = 70). Among them, C. minutus stands out with 45 different cytotypes already identified, among which, seven parental ones, named A to G, are parapatrically distributed in the coastal plains of Southern Brazil. Looking for possible causes that led to such extensive karyotype diversification, we performed chromosomal mapping of different repetitive DNAs, including microsatellites and long interspersed element-1 (LINE-1) retrotransposons in the seven parental cytotypes. Although microsatellites were found mainly in the centromeric and telomeric regions of the chromosomes, different patterns occur for each cytotype, thus revealing specific features. Likewise, the LINE-1-like retrotransposons also showed a differential distribution for each cytotype, which may be linked to stochastic loss of LINE-1 in some populations. Here, microsatellite motifs (A)30, (C)30, (CA)15, (CAC)10, (CAG)10, (CGG)10, (GA)15, and (GAG)10 could be mapped to fusion of chromosomes 20/17, fission and inversion in the short arm of chromosome 2, fusion of chromosomes 23/19, and different combinations of centric and tandem fusions of chromosomes 22/24/16. These data provide evidence for a correlation between repetitive genomic content and localization of evolutionary breakpoints and highlight their direct impact in promoting chromosomal rearrangements.
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He Y, Guo L, Zheng L, Ren C, Wang T, Lu J. Clinical and molecular cytogenetic findings and pregnancy outcomes of fetuses with isochromosome Y. Mol Cytogenet 2022; 15:32. [PMID: 35927742 PMCID: PMC9351221 DOI: 10.1186/s13039-022-00611-3] [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: 06/08/2022] [Accepted: 07/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The mosaic forms and clinical phenotypes of fetuses with isochromosome Y are difficult to predict. Therefore, we summarized the cases of nine fetuses with isochromosome Y identified in prenatal diagnosis with a combination of molecular cytogenetic techniques, providing clinical evidence for prenatal genetic counseling. METHODS The prenatal diagnosis and pregnancy outcomes of nine fetuses with isochromosome Y were obtained by a retrospective analysis. Isochromosome Y was identified prenatally by different approaches, such as conventional karyotyping, chromosomal microarray analysis (CMA), quantitative fluorescent polymerase chain reaction (QF-PCR) and fluorescence in situ hybridization (FISH). RESULTS Seven idic(Y) fetuses and two i(Y) fetuses were identified. One fetus was complete for i(Y)(p10), and the rest with 45,X had mosaic forms. A break and fusion locus was identified in Yp11.3 in one fetus, in Yq11.22 in six fetuses and in Yp10 in two fetuses. The CMA results suggested that different deletions and duplications were found on the Y chromosome. The deletion fragments ranged from 4.7 Mb to the entire Y chromosome, and the duplication fragments ranged from 10.4 to 18.0 Mb. QF-PCR analysis suggested that the AZF region was intact in one fetus, four fetuses had AZFb+c+d deletion, one fetus had AZFa+b+c+d deletion, and one fetus had AZFc+d deletion. Finally, four healthy male neonates were delivered successfully, but the parents of the remaining five fetuses, including three healthy and two unhealthy fetuses, chose to terminate their pregnancies. CONCLUSION The fetus and neonate phenotype of prenatally detected isochromosome Y usually is that of a normally developed male, ascertained in the absence of other indicators of a fetal structural anomaly. Our study provides clinical reference materials for risk assessment and permits better prenatally counseling and preparation of parents facing the birth of isochromosome Y fetuses.
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Affiliation(s)
- Yiqun He
- Prenatal Diagnosis Centre, Guangdong Women and Children Hospital, 521-523 Xingnan Road, Guangzhou, 511442, Guangdong, China
| | - Li Guo
- Prenatal Diagnosis Centre, Guangdong Women and Children Hospital, 521-523 Xingnan Road, Guangzhou, 511442, Guangdong, China
| | - Laiping Zheng
- Prenatal Diagnosis Centre, Guangdong Women and Children Hospital, 521-523 Xingnan Road, Guangzhou, 511442, Guangdong, China
| | - Congmian Ren
- Prenatal Diagnosis Centre, Guangdong Women and Children Hospital, 521-523 Xingnan Road, Guangzhou, 511442, Guangdong, China
| | - Ting Wang
- Prenatal Diagnosis Centre, Guangdong Women and Children Hospital, 521-523 Xingnan Road, Guangzhou, 511442, Guangdong, China
| | - Jian Lu
- Prenatal Diagnosis Centre, Guangdong Women and Children Hospital, 521-523 Xingnan Road, Guangzhou, 511442, Guangdong, China.
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Ji F, Zhu X, Liao H, Ouyang L, Huang Y, Syeda MZ, Ying S. New Era of Mapping and Understanding Common Fragile Sites: An Updated Review on Origin of Chromosome Fragility. Front Genet 2022; 13:906957. [PMID: 35669181 PMCID: PMC9164283 DOI: 10.3389/fgene.2022.906957] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Common fragile sites (CFSs) are specific genomic loci prone to forming gaps or breakages upon replication perturbation, which correlate well with chromosomal rearrangement and copy number variation. CFSs have been actively studied due to their important pathophysiological relevance in different diseases such as cancer and neurological disorders. The genetic locations and sequences of CFSs are crucial to understanding the origin of such unstable sites, which require reliable mapping and characterizing approaches. In this review, we will inspect the evolving techniques for CFSs mapping, especially genome-wide mapping and sequencing of CFSs based on current knowledge of CFSs. We will also revisit the well-established hypotheses on the origin of CFSs fragility, incorporating novel findings from the comprehensive analysis of finely mapped CFSs regarding their locations, sequences, and replication/transcription, etc. This review will present the most up-to-date picture of CFSs and, potentially, a new framework for future research of CFSs.
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Affiliation(s)
- Fang Ji
- International Institutes of Medicine, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, China.,Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Key Laboratory of Respiratory Disease of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Xinli Zhu
- Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Key Laboratory of Respiratory Disease of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Hongwei Liao
- International Institutes of Medicine, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, China.,Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Key Laboratory of Respiratory Disease of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Liujian Ouyang
- Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Key Laboratory of Respiratory Disease of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Yingfei Huang
- Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Key Laboratory of Respiratory Disease of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Madiha Zahra Syeda
- Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Key Laboratory of Respiratory Disease of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Songmin Ying
- International Institutes of Medicine, The Fourth Affiliated Hospital of Zhejiang University School of Medicine, Yiwu, China.,Department of Pharmacology and Department of Respiratory and Critical Care Medicine of the Second Affiliated Hospital, Key Laboratory of Respiratory Disease of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
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CircPVT1: a pivotal circular node intersecting Long Non-Coding-PVT1 and c-MYC oncogenic signals. Mol Cancer 2022; 21:33. [PMID: 35090471 PMCID: PMC8796571 DOI: 10.1186/s12943-022-01514-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/18/2022] [Indexed: 12/11/2022] Open
Abstract
The role of circular RNAs in oncogenesis has begun to be widely studied in recent years, due to the significant impact that these molecules have in disease pathogenesis, as well as their potential for the future of innovative therapies. Moreover, due to their characteristically circular shape, circular RNAs are very resistant molecules to RNA degradation whose levels are easily assessed in body fluids. Accordingly, they represent an opportunity for the discovery of new diagnostic and prognostic markers in a wide range of diseases. Among circular RNAs, circPVT1 is a rather peculiar one that originates from the circularization of the exon 2 of the PVT1 gene that encodes a pro-tumorigenic long non-coding RNA named lncPVT1. There are a few examples of circular RNAs that derive from a locus producing another non-coding RNA. Despite their apparent transcriptional independence, which occurs using two different promoters, a possible synergistic effect in tumorigenesis cannot be excluded considering that both have been reported to correlate with the oncogenic phenotype. This complex mechanism of regulation appears to also be controlled by c-MYC. Indeed, the PVT1 locus is located only 53 Kb downstream c-MYC gene, a well-known oncogene that regulates the expression levels of about 15% of all genes. Here, we review circPVT1 origin and biogenesis highlighting the most important mechanisms through which it plays a fundamental role in oncogenesis, such as the well-known sponge activity on microRNAs, as well as its paradigmatic interactome link with lncPVT1 and c-MYC expression.
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Pechlivanis M, Campbell BK, Hovens CM, Corcoran NM. Biomarkers of Response to Neoadjuvant Androgen Deprivation in Localised Prostate Cancer. Cancers (Basel) 2021; 14:cancers14010166. [PMID: 35008330 PMCID: PMC8750084 DOI: 10.3390/cancers14010166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/15/2021] [Accepted: 12/22/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Prostate cancer is the second leading cause of cancer deaths in men. Attempts to improve patient outcomes include trials of neoadjuvant androgen deprivation therapy for patients with high-risk disease. Neoadjuvant treatment refers to androgen deprivation therapy that is administered prior to surgery (or radiation therapy). Patients typically respond well to this treatment regimen, showing a decrease in tumour size, but a significant proportion of patients eventually relapse and progress to metastatic disease. The mechanisms driving this resistance to neoadjuvant treatment are currently unknown. This review explores theories of resistance broadly, and their possible applications in the prostate cancer setting. Additionally, this review draws comparisons between breakthrough resistance and neoadjuvant resistance, and lastly investigates the current biomarkers for treatment sensitivity. Abstract Prostate cancer (PCa) is a hormone driven cancer, characterised by defects in androgen receptor signalling which drive the disease process. As such, androgen targeted therapies have been the mainstay for PCa treatment for over 70 years. High-risk PCa presents unique therapeutic challenges, namely in minimising the primary tumour, and eliminating any undetected micro metastases. Trials of neoadjuvant androgen deprivation therapy aim to address these challenges. Patients typically respond well to neoadjuvant treatment, showing regression of the primary tumour and negative surgical margins at the time of resection, however the majority of patients relapse and progress to metastatic disease. The mechanisms affording this resistance are largely unknown. This commentary attempts to explore theories of resistance more broadly, namely, clonal evolution, cancer stem cells, cell persistence, and drug tolerance. Moreover, it aims to explore the application of these theories in the PCa setting. This commentary also highlights the distinction between castration resistant PCa, and neoadjuvant resistant disease, and identifies the markers and characteristics of neoadjuvant resistant disease presented by current literature.
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Affiliation(s)
- Maree Pechlivanis
- Department of Surgery, University of Melbourne, Parkville, VIC 3050, Australia; (B.K.C.); (C.M.H.); (N.M.C.)
- Correspondence: ; Tel.: +61-3-9342-7294; Fax: +61-3-9342-8928
| | - Bethany K. Campbell
- Department of Surgery, University of Melbourne, Parkville, VIC 3050, Australia; (B.K.C.); (C.M.H.); (N.M.C.)
| | - Christopher M. Hovens
- Department of Surgery, University of Melbourne, Parkville, VIC 3050, Australia; (B.K.C.); (C.M.H.); (N.M.C.)
| | - Niall M. Corcoran
- Department of Surgery, University of Melbourne, Parkville, VIC 3050, Australia; (B.K.C.); (C.M.H.); (N.M.C.)
- Department of Urology, Royal Melbourne Hospital, Parkville, VIC 3050, Australia
- Department of Urology, Western Health, Footscray, VIC 3011, Australia
- Victorian Comprehensive Cancer Centre, Melbourne, VIC 3000, Australia
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Hadi K, Yao X, Behr JM, Deshpande A, Xanthopoulakis C, Tian H, Kudman S, Rosiene J, Darmofal M, DeRose J, Mortensen R, Adney EM, Shaiber A, Gajic Z, Sigouros M, Eng K, Wala JA, Wrzeszczyński KO, Arora K, Shah M, Emde AK, Felice V, Frank MO, Darnell RB, Ghandi M, Huang F, Dewhurst S, Maciejowski J, de Lange T, Setton J, Riaz N, Reis-Filho JS, Powell S, Knowles DA, Reznik E, Mishra B, Beroukhim R, Zody MC, Robine N, Oman KM, Sanchez CA, Kuhner MK, Smith LP, Galipeau PC, Paulson TG, Reid BJ, Li X, Wilkes D, Sboner A, Mosquera JM, Elemento O, Imielinski M. Distinct Classes of Complex Structural Variation Uncovered across Thousands of Cancer Genome Graphs. Cell 2021; 183:197-210.e32. [PMID: 33007263 DOI: 10.1016/j.cell.2020.08.006] [Citation(s) in RCA: 124] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 04/08/2020] [Accepted: 08/03/2020] [Indexed: 12/12/2022]
Abstract
Cancer genomes often harbor hundreds of somatic DNA rearrangement junctions, many of which cannot be easily classified into simple (e.g., deletion) or complex (e.g., chromothripsis) structural variant classes. Applying a novel genome graph computational paradigm to analyze the topology of junction copy number (JCN) across 2,778 tumor whole-genome sequences, we uncovered three novel complex rearrangement phenomena: pyrgo, rigma, and tyfonas. Pyrgo are "towers" of low-JCN duplications associated with early-replicating regions, superenhancers, and breast or ovarian cancers. Rigma comprise "chasms" of low-JCN deletions enriched in late-replicating fragile sites and gastrointestinal carcinomas. Tyfonas are "typhoons" of high-JCN junctions and fold-back inversions associated with expressed protein-coding fusions, breakend hypermutation, and acral, but not cutaneous, melanomas. Clustering of tumors according to genome graph-derived features identified subgroups associated with DNA repair defects and poor prognosis.
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Affiliation(s)
- Kevin Hadi
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA
| | - Xiaotong Yao
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA; Tri-institutional PhD Program in Computational Biology and Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Julie M Behr
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA; Tri-institutional PhD Program in Computational Biology and Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Aditya Deshpande
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA; Tri-institutional PhD Program in Computational Biology and Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | | | - Huasong Tian
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA
| | - Sarah Kudman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Joel Rosiene
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA
| | - Madison Darmofal
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA; Tri-institutional PhD Program in Computational Biology and Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | | | | | - Emily M Adney
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA
| | - Alon Shaiber
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA; Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Zoran Gajic
- New York Genome Center, New York, NY 10013, USA
| | - Michael Sigouros
- Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Kenneth Eng
- Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Jeremiah A Wala
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Departments of Medical Oncology and Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | | | | | - Minita Shah
- New York Genome Center, New York, NY 10013, USA
| | | | | | - Mayu O Frank
- New York Genome Center, New York, NY 10013, USA; Laboratory of Molecular Neuro-Oncology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Robert B Darnell
- New York Genome Center, New York, NY 10013, USA; Laboratory of Molecular Neuro-Oncology and Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
| | - Mahmoud Ghandi
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Franklin Huang
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Sally Dewhurst
- Laboratory of Cell Biology and Genetics, The Rockefeller University, New York, NY 10065, USA
| | - John Maciejowski
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Titia de Lange
- Laboratory of Cell Biology and Genetics, The Rockefeller University, New York, NY 10065, USA
| | - Jeremy Setton
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Nadeem Riaz
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Immunogenomics and Precision Oncology Platform, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Jorge S Reis-Filho
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Simon Powell
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - David A Knowles
- New York Genome Center, New York, NY 10013, USA; Department of Computer Science, Columbia University, New York, NY 10027, USA
| | - Ed Reznik
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Bud Mishra
- Departments of Computer Science, Mathematics and Cell Biology, Courant Institute and NYU School of Medicine, New York University, New York, NY 10012, USA
| | - Rameen Beroukhim
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA; Departments of Medical Oncology and Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | | | | | - Kenji M Oman
- Divisions of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Carissa A Sanchez
- Divisions of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Mary K Kuhner
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Lucian P Smith
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Patricia C Galipeau
- Divisions of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Thomas G Paulson
- Divisions of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Brian J Reid
- Divisions of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Xiaohong Li
- Divisions of Human Biology and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - David Wilkes
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Andrea Sboner
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Juan Miguel Mosquera
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Olivier Elemento
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10021, USA
| | - Marcin Imielinski
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY 10021, USA; New York Genome Center, New York, NY 10013, USA; Englander Institute for Precision Medicine, Weill Cornell Medicine, New York, NY 10021, USA; Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY 10021, USA.
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Simpson BS, Pye H, Whitaker HC. The oncological relevance of fragile sites in cancer. Commun Biol 2021; 4:567. [PMID: 33980983 PMCID: PMC8115686 DOI: 10.1038/s42003-021-02020-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 03/12/2021] [Indexed: 01/15/2023] Open
Abstract
Recent developments in sequencing the cancer genome have provided the first in-depth mapping of structural variants (SV) across 38 tumour types. Sixteen signatures of structural variants have been proposed which broadly characterise the variation seen across cancer types. One signature shows increased duplications and deletions at fragile sites, with little association with the typical DNA repair defects. We discuss how, for many of these fragile sites, the clinical impacts are yet to be explored. One example is NAALADL2, one of the most frequently altered fragile sites in the cancer genome. The copy-number variations (CNVs) which occur at fragile sites, such as NAALADL2, may span many genes without typical DNA repair defects and could have a large impact on cell signalling. In this Perspective, Simpson, Pye, and Whitaker discuss recent research identifying structural genomic variants in human cancers with a particular focus on deletions and duplications at genomic fragile sites. They argue that tumours with predominantly fragile site structural variants represent a distinct mutational signature that warrants further research.
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Affiliation(s)
- Benjamin S Simpson
- Molecular Diagnostics and Therapeutics Group, Research Department of Targeted Intervention, Division of Surgery & Interventional Science, University College London, London, UK
| | - Hayley Pye
- Molecular Diagnostics and Therapeutics Group, Research Department of Targeted Intervention, Division of Surgery & Interventional Science, University College London, London, UK
| | - Hayley C Whitaker
- Molecular Diagnostics and Therapeutics Group, Research Department of Targeted Intervention, Division of Surgery & Interventional Science, University College London, London, UK.
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10
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Qiu Q, Zhou Q, Luo A, Li X, Li K, Li W, Yu M, Amanullah M, Lu B, Lu W, Liu P, Lu Y. Integrated analysis of virus and host transcriptomes in cervical cancer in Asian and Western populations. Genomics 2021; 113:1554-1564. [PMID: 33785400 DOI: 10.1016/j.ygeno.2021.03.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 03/09/2021] [Accepted: 03/26/2021] [Indexed: 12/31/2022]
Abstract
Race may influence vulnerability to HPV variants in viral infection and perisistence. Integrated analysis of the virus and host transcriptomes from different populations provides an unprecedented opportunity to understand these racial disparities in the prevalence of HPV and cervical cancers. We performed RNA-Seq analysis of 90 tumors and 39 adjacent normal tissues from cervical cancer patients at Zhejiang University (ZJU) in China, and conducted a comparative analysis with RNA-Seq data of 286 cervical cancers from TCGA. We found a modestly higher rate of HPV positives and HPV integrations in TCGA than in ZJU. In addition to LINC00393 and HSPB3 as new common integration hotspots in both cohorts, we found new hotspots such as SH2D3C and CASC8 in TCGA, and SCGB1A1 and ABCA1 in ZJU. We described the first, to our knowledge, virus-transcriptome-based classification of cervical cancer associated with clinical outcome. Particularly, patients with expressed E5 performed better than those without E5 expression. However, the constituents of these virus-transcriptome-based tumor subtypes differ dramatically between the two cohorts. We further characterized the immune infiltration landscapes between different HPV statuses and revealed significantly elevated levels of regulatory T cells and M0 macrophages in HPV positive tumors, which were associated with poor prognosis. These findings increase our understanding of the racial disparities in the prevalence of HPV and its associated cervical cancers between the two cohorts, and also have important implications in the classification of tumor subtypes, prognosis, and anti-cancer immunotherapy in cervical cancer.
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Affiliation(s)
- Qiongzi Qiu
- Center for Uterine Cancer Diagnosis & Therapy Research of Zhejiang Province, Women's Reproductive Health Key Laboratory of Zhejiang Province, Department of Gynecologic Oncology, Women's Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310002, China
| | - Qing Zhou
- Center for Uterine Cancer Diagnosis & Therapy Research of Zhejiang Province, Women's Reproductive Health Key Laboratory of Zhejiang Province, Department of Gynecologic Oncology, Women's Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310002, China
| | - Aoran Luo
- Center for Uterine Cancer Diagnosis & Therapy Research of Zhejiang Province, Women's Reproductive Health Key Laboratory of Zhejiang Province, Department of Gynecologic Oncology, Women's Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310002, China
| | - Xufan Li
- Department of Respiratory Medicine, Sir Run Run Shaw Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China
| | - Kezhen Li
- Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Wenfeng Li
- Department of Radiation Oncology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
| | - Mengqian Yu
- Center for Uterine Cancer Diagnosis & Therapy Research of Zhejiang Province, Women's Reproductive Health Key Laboratory of Zhejiang Province, Department of Gynecologic Oncology, Women's Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310002, China
| | - Md Amanullah
- Center for Uterine Cancer Diagnosis & Therapy Research of Zhejiang Province, Women's Reproductive Health Key Laboratory of Zhejiang Province, Department of Gynecologic Oncology, Women's Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310002, China
| | - Bingjian Lu
- Center for Uterine Cancer Diagnosis & Therapy Research of Zhejiang Province, Women's Reproductive Health Key Laboratory of Zhejiang Province, Department of Gynecologic Oncology, Women's Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310002, China; Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China
| | - Weiguo Lu
- Center for Uterine Cancer Diagnosis & Therapy Research of Zhejiang Province, Women's Reproductive Health Key Laboratory of Zhejiang Province, Department of Gynecologic Oncology, Women's Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310002, China; Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China.
| | - Pengyuan Liu
- Department of Respiratory Medicine, Sir Run Run Shaw Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, China; Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China; Center of Systems Molecular Medicine, Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Yan Lu
- Center for Uterine Cancer Diagnosis & Therapy Research of Zhejiang Province, Women's Reproductive Health Key Laboratory of Zhejiang Province, Department of Gynecologic Oncology, Women's Hospital and Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310002, China; Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310029, China.
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11
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Özer L, Ruhi HI, Bökesoy I. Analysis of Xq27.3 Fragility Using the Micronucleus-Fluorescence In situ Hybridization Assay. Genome Integr 2020; 11:1. [PMID: 33110486 PMCID: PMC7585461 DOI: 10.4103/genint.genint_4_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Chromosome fragile sites tend to form gap or break in chromosomes when the cells are exposed to replication stress. Folic acid deprivation in the culture medium induces folate-sensitive rare fragile sites, such as FRAXA which is responsible for the fragile X mental retardation syndrome. Chromosome instability at fragile sites can be evaluated by biomarkers of genomic instability such as frequency of micronuclei (MN). It was aimed to analyse the chromosome content of MN in Fragile X cells during folate deprivation by the MN-fluorescence in situ hybridization (FISH) method. Samples from five Fragile X syndrome patients, diagnosed using cytogenetic and molecular methods, as well as from their parents and five controls were included in the study. Blood samples were cultured in two different culture media (folate-deficient and normal). Results of MN-FISH test were analysed in terms of MN frequency and chromosome content of MN. An accumulation of MN in Fragile X patients, mainly containing T (+) or C (+) MN or T (+) plus C (+) MN in binucleated cells was found. Finally, MN-FISH analysis allowed confirming that the increase in MN frequency is due to a higher sensitivity to chromosome breakage along the X chromosome.
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Affiliation(s)
- Leyla Özer
- Mikrogen Genetic Diagnosis Center, Ankara, Turkey.,Division of Medical Genetics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Hatice Ilgın Ruhi
- Division of Medical Genetics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Işık Bökesoy
- Division of Medical Genetics, Faculty of Medicine, Ankara University, Ankara, Turkey
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12
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Folate stress induces SLX1- and RAD51-dependent mitotic DNA synthesis at the fragile X locus in human cells. Proc Natl Acad Sci U S A 2020; 117:16527-16536. [PMID: 32601218 PMCID: PMC7368274 DOI: 10.1073/pnas.1921219117] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Folate deficiency is associated with multiple disorders in humans. Through the analysis of the fragile X syndrome locus (FRAXA) in immortalized human lymphocytes or fibroblasts, we demonstrate that FRAXA undergoes DNA synthesis in mitosis (MiDAS). We demonstrate that this process occurs via break-induced DNA replication and requires the SLX1/SLX4 endonuclease complex, the RAD51 recombinase and POLD3, a subunit of polymerase delta. We also demonstrate that other loci undergo MiDAS upon folate stress. This study reveals a function of human SLX1 in the maintenance of FRAXA stability and provides evidence that, in addition to FRAXA, MiDAS occurs at other loci following folate deprivation. These findings provide insight into the diverse and detrimental consequences of folate deficiency in human cells. Folate deprivation drives the instability of a group of rare fragile sites (RFSs) characterized by CGG trinucleotide repeat (TNR) sequences. Pathological expansion of the TNR within the FRAXA locus perturbs DNA replication and is the major causative factor for fragile X syndrome, a sex-linked disorder associated with cognitive impairment. Although folate-sensitive RFSs share many features with common fragile sites (CFSs; which are found in all individuals), they are induced by different stresses and share no sequence similarity. It is known that a pathway (termed MiDAS) is employed to complete the replication of CFSs in early mitosis. This process requires RAD52 and is implicated in generating translocations and copy number changes at CFSs in cancers. However, it is unclear whether RFSs also utilize MiDAS and to what extent the fragility of CFSs and RFSs arises by shared or distinct mechanisms. Here, we demonstrate that MiDAS does occur at FRAXA following folate deprivation but proceeds via a pathway that shows some mechanistic differences from that at CFSs, being dependent on RAD51, SLX1, and POLD3. A failure to complete MiDAS at FRAXA leads to severe locus instability and missegregation in mitosis. We propose that break-induced DNA replication is required for the replication of FRAXA under folate stress and define a cellular function for human SLX1. These findings provide insights into how folate deprivation drives instability in the human genome.
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13
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Jin K, Wang S, Zhang Y, Xia M, Mo Y, Li X, Li G, Zeng Z, Xiong W, He Y. Long non-coding RNA PVT1 interacts with MYC and its downstream molecules to synergistically promote tumorigenesis. Cell Mol Life Sci 2019; 76:4275-4289. [PMID: 31309249 PMCID: PMC6803569 DOI: 10.1007/s00018-019-03222-1] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 06/22/2019] [Accepted: 07/05/2019] [Indexed: 02/06/2023]
Abstract
Numerous studies have shown that non-coding RNAs play crucial roles in the development and progression of various tumor cells. Plasmacytoma variant translocation 1 (PVT1) mainly encodes a long non-coding RNA (lncRNA) and is located on chromosome 8q24.21, which constitutes a fragile site for genetic aberrations. PVT1 is well-known for its interaction with its neighbor MYC, which is a qualified oncogene that plays a vital role in tumorigenesis. In the past several decades, increasing attention has been paid to the interaction mechanism between PVT1 and MYC, which will benefit the clinical treatment and prognosis of patients. In this review, we summarize the coamplification of PVT1 and MYC in cancer, the positive feedback mechanism, and the latest promoter competition mechanism of PVT1 and MYC, as well as how PVT1 participates in the downstream signaling pathway of c-Myc by regulating key molecules. We also briefly describe the treatment prospects and research directions of PVT1 and MYC.
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Affiliation(s)
- Ke Jin
- NHC Key Laboratory of Carcinogenesis (Central South University) and Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shufei Wang
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Yazhuo Zhang
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Mengfang Xia
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Yongzhen Mo
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
| | - Xiaoling Li
- NHC Key Laboratory of Carcinogenesis (Central South University) and Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Guiyuan Li
- NHC Key Laboratory of Carcinogenesis (Central South University) and Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhaoyang Zeng
- NHC Key Laboratory of Carcinogenesis (Central South University) and Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wei Xiong
- NHC Key Laboratory of Carcinogenesis (Central South University) and Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China.
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | - Yi He
- NHC Key Laboratory of Carcinogenesis (Central South University) and Hunan Key Laboratory of Translational Radiation Oncology, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China.
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, Hunan, China.
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14
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Lyu X, Chastain M, Chai W. Genome-wide mapping and profiling of γH2AX binding hotspots in response to different replication stress inducers. BMC Genomics 2019; 20:579. [PMID: 31299901 PMCID: PMC6625122 DOI: 10.1186/s12864-019-5934-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 06/25/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Replication stress (RS) gives rise to DNA damage that threatens genome stability. RS can originate from different sources that stall replication by diverse mechanisms. However, the mechanism underlying how different types of RS contribute to genome instability is unclear, in part due to the poor understanding of the distribution and characteristics of damage sites induced by different RS mechanisms. RESULTS We use ChIP-seq to map γH2AX binding sites genome-wide caused by aphidicolin (APH), hydroxyurea (HU), and methyl methanesulfonate (MMS) treatments in human lymphocyte cells. Mapping of γH2AX ChIP-seq reveals that APH, HU, and MMS treatments induce non-random γH2AX chromatin binding at discrete regions, suggesting that there are γH2AX binding hotspots in the genome. Characterization of the distribution and sequence/epigenetic features of γH2AX binding sites reveals that the three treatments induce γH2AX binding at largely non-overlapping regions, suggesting that RS may cause damage at specific genomic loci in a manner dependent on the fork stalling mechanism. Nonetheless, γH2AX binding sites induced by the three treatments share common features including compact chromatin, coinciding with larger-than-average genes, and depletion of CpG islands and transcription start sites. Moreover, we observe significant enrichment of SINEs in γH2AX sites in all treatments, indicating that SINEs may be a common barrier for replication polymerases. CONCLUSIONS Our results identify the location and common features of genome instability hotspots induced by different types of RS, and help in deciphering the mechanisms underlying RS-induced genetic diseases and carcinogenesis.
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Affiliation(s)
- Xinxing Lyu
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, Washington, USA
| | - Megan Chastain
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, Washington, USA
| | - Weihang Chai
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, Washington, USA.
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15
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Meroni A, Nava GM, Bianco E, Grasso L, Galati E, Bosio MC, Delmastro D, Muzi-Falconi M, Lazzaro F. RNase H activities counteract a toxic effect of Polymerase η in cells replicating with depleted dNTP pools. Nucleic Acids Res 2019; 47:4612-4623. [PMID: 30847483 PMCID: PMC6511917 DOI: 10.1093/nar/gkz165] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 02/25/2019] [Accepted: 03/01/2019] [Indexed: 01/27/2023] Open
Abstract
RNA:DNA hybrids are transient physiological intermediates that arise during several cellular processes such as DNA replication. In pathological situations, they may stably accumulate and pose a threat to genome integrity. Cellular RNase H activities process these structures to restore the correct DNA:DNA sequence. Yeast cells lacking RNase H are negatively affected by depletion of deoxyribonucleotide pools necessary for DNA replication. Here we show that the translesion synthesis DNA polymerase η (Pol η) plays a role in DNA replication under low deoxyribonucleotides condition triggered by hydroxyurea. In particular, the catalytic reaction performed by Pol η is detrimental for RNase H deficient cells, causing DNA damage checkpoint activation and G2/M arrest. Moreover, a Pol η mutant allele with enhanced ribonucleotide incorporation further exacerbates the sensitivity to hydroxyurea of cells lacking RNase H activities. Our data are compatible with a model in which Pol η activity facilitates the formation or stabilization of RNA:DNA hybrids at stalled replication forks. However, in a scenario where RNase H activity fails to restore DNA, these hybrids become highly toxic for cells.
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Affiliation(s)
- Alice Meroni
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Giulia Maria Nava
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Eliana Bianco
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Lavinia Grasso
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Elena Galati
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Maria Cristina Bosio
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Daria Delmastro
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Marco Muzi-Falconi
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
| | - Federico Lazzaro
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy
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16
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Chon J, Field MS, Stover PJ. Deoxyuracil in DNA and disease: Genomic signal or managed situation? DNA Repair (Amst) 2019; 77:36-44. [PMID: 30875637 DOI: 10.1016/j.dnarep.2019.02.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 02/26/2019] [Indexed: 12/21/2022]
Abstract
Genomic instability is implicated in the etiology of several deleterious health outcomes including megaloblastic anemia, neural tube defects, and neurodegeneration. Uracil misincorporation and its repair are known to cause genomic instability by inducing DNA strand breaks leading to apoptosis, but there is emerging evidence that uracil incorporation may also result in broader modifications of gene expression, including: changes in transcriptional stalling, strand break-mediated transcriptional upregulation, and direct promoter inhibition. The factors that influence uracil levels in DNA are cytosine deamination, de novo thymidylate (dTMP) biosynthesis, salvage dTMP biosynthesis, dUTPase, and DNA repair. There is evidence that the nuclear localization of the enzymes in these pathways in mammalian cells may modify and/or control the levels of uracil accumulation into nuclear DNA. Uracil sequencing technologies demonstrate that uracil in DNA is not distributed stochastically across the genome, but instead shows patterns of enrichment. Nuclear localization of the enzymes that modify uracil in DNA may serve to change these patterns of enrichment in a tissue-specific manner, and thereby signal the genome in response to metabolic and/or nutritional state of the cell.
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Affiliation(s)
- James Chon
- Graduate Field of Biochemistry, Molecular and Cellular Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Martha S Field
- Division of Nutritional Sciences, Cornell University, 127 Savage Hall, Ithaca, NY, 14853, USA
| | - Patrick J Stover
- Graduate Field of Biochemistry, Molecular and Cellular Biology, Cornell University, Ithaca, NY, 14853, USA; Division of Nutritional Sciences, Cornell University, 127 Savage Hall, Ithaca, NY, 14853, USA.
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17
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Kaushal S, Freudenreich CH. The role of fork stalling and DNA structures in causing chromosome fragility. Genes Chromosomes Cancer 2019; 58:270-283. [PMID: 30536896 DOI: 10.1002/gcc.22721] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/13/2018] [Accepted: 12/03/2018] [Indexed: 12/19/2022] Open
Abstract
Alternative non-B form DNA structures, also called secondary structures, can form in certain DNA sequences under conditions that produce single-stranded DNA, such as during replication, transcription, and repair. Direct links between secondary structure formation, replication fork stalling, and genomic instability have been found for many repeated DNA sequences that cause disease when they expand. Common fragile sites (CFSs) are known to be AT-rich and break under replication stress, yet the molecular basis for their fragility is still being investigated. Over the past several years, new evidence has linked both the formation of secondary structures and transcription to fork stalling and fragility of CFSs. How these two events may synergize to cause fragility and the role of nuclease cleavage at secondary structures in rare and CFSs are discussed here. We also highlight evidence for a new hypothesis that secondary structures at CFSs not only initiate fragility but also inhibit healing, resulting in their characteristic appearance.
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Affiliation(s)
- Simran Kaushal
- Department of Biology, Tufts University, Medford, Massachusetts
| | - Catherine H Freudenreich
- Department of Biology, Tufts University, Medford, Massachusetts.,Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts
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18
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Debatisse M, Rosselli F. A journey with common fragile sites: From S phase to telophase. Genes Chromosomes Cancer 2018; 58:305-316. [PMID: 30387289 DOI: 10.1002/gcc.22704] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 10/25/2018] [Indexed: 12/17/2022] Open
Abstract
Some regions of the genome, notably common fragile sites (CFSs), are hypersensitive to replication stress and often involved in the generation of gross chromosome rearrangements in cancer cells. CFSs nest within very large genes and display cell-type-dependent instability. Fragile or not, large genes tend to replicate late in S-phase. A number of data now show that transcription perturbs replication completion across the body of large genes, particularly upon replication stress. However, the molecular mechanisms by which transcription elicits such under-replication and subsequent instability remain unclear. We present here our view of the mechanisms responsible for CFS under-replication and those allowing the cells to cope with this problem in G2 and mitosis. We notably focus on the major role played by the FANC proteins in the protection of CFSs from S phase up to late mitosis. We finally discuss a possible rationale for the conservation of large genes across vertebrate evolution.
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Affiliation(s)
- Michelle Debatisse
- CNRS UMR 8200, Equipe labellisée "La ligue Contre le Cancer", Villejuif, France.,Sorbonne Universités, UPMC Univ Paris 06, Paris, France.,Gustave Roussy Cancer Center, Villejuif, France
| | - Filippo Rosselli
- CNRS UMR 8200, Equipe labellisée "La ligue Contre le Cancer", Villejuif, France.,Gustave Roussy Cancer Center, Villejuif, France.,Université Paris Saclay - Paris Sud, Orsay, France
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19
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Palumbo E, Russo A. Common fragile site instability in normal cells: Lessons and perspectives. Genes Chromosomes Cancer 2018; 58:260-269. [PMID: 30387295 DOI: 10.1002/gcc.22705] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/25/2018] [Accepted: 10/01/2018] [Indexed: 12/26/2022] Open
Abstract
Mechanisms and events related to common fragile site (CFS) instability are well known in cancer cells. Here, we argue that normal cells remain an important experimental model to address questions related to CFS instability in the absence of alterations in cell cycle and DNA damage repair pathways, which are common features acquired in cancer. Furthermore, a major gap of knowledge concerns the stability of CFSs during gametogenesis. CFS instability in meiotic or postmeiotic stages of the germ cell line could generate chromosome deletions or large rearrangements. This in turn can lead to the functional loss of the several CFS-associated genes with tumor suppressor function. Our hypothesis is that such mutations can potentially result in genetic predisposition to develop cancer. Indirect evidence for CFS instability in human germ cells has been provided by genomic investigations in family pedigrees associated with genetic disease. The issue of CFS instability in the germ cell line should represent one of the future efforts, and may take advantage of the existence of sequence and functional conservation of CFSs between rodents and humans.
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Affiliation(s)
- Elisa Palumbo
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Antonella Russo
- Department of Molecular Medicine, University of Padova, Padova, Italy
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20
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Wójcik E, Szostek M, Horoszewicz E, Kot E, Sebastian S, Smalec E. Analysis of chromatin instability of somatic cells in sheep. CANADIAN JOURNAL OF ANIMAL SCIENCE 2018. [DOI: 10.1139/cjas-2017-0078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cytogenetic tests are highly reliable, sensitive indicators of the early effects of genomic instability. Their results provide information on the organism’s susceptibility to exogenous and endogenous factors and are measures of the degree of repair of DNA damage. Our study assessed spontaneously occurring damage in following four breeds of sheep: Polish Heath, Polish Lowland (Zelazna variety), Polish Blackhead, and Berrichon du Cher. Instability was identified using the following three different tests: a sister chromatid exchange (SCE) assay, identification of fragile sites, and the comet assay. The distribution of instabilities varied depending on the breed. The mean frequency of SCEs was 5.13 ± 1.58, whereas that of fragile sites was 3.30 ± 1.24. The mean level of DNA damage (% head DNA) was 96.52 ± 6.59. The most damage to genetic material was observed in the Berrichon du Cher sheep, and the least in the Polish Heath sheep. The tests used are reliable biomarkers of genome stability in animal breeds, as well as in individuals within breeds.
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Affiliation(s)
- Ewa Wójcik
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
| | - Małgorzata Szostek
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
| | - Elżbieta Horoszewicz
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
| | - Emilia Kot
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
| | - Sałuch Sebastian
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
| | - Elżbieta Smalec
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
- Institute of Bioengineering and Animal Breeding, Siedlce University of Natural Sciences and Humanities, Prusa 14 St, Siedlce 08-110, Poland
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21
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van Emden TS, Forn M, Forné I, Sarkadi Z, Capella M, Martín Caballero L, Fischer-Burkart S, Brönner C, Simonetta M, Toczyski D, Halic M, Imhof A, Braun S. Shelterin and subtelomeric DNA sequences control nucleosome maintenance and genome stability. EMBO Rep 2018; 20:embr.201847181. [PMID: 30420521 DOI: 10.15252/embr.201847181] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 10/03/2018] [Accepted: 10/12/2018] [Indexed: 11/09/2022] Open
Abstract
Telomeres and the shelterin complex cap and protect the ends of chromosomes. Telomeres are flanked by the subtelomeric sequences that have also been implicated in telomere regulation, although their role is not well defined. Here, we show that, in Schizosaccharomyces pombe, the telomere-associated sequences (TAS) present on most subtelomeres are hyper-recombinogenic, have metastable nucleosomes, and unusual low levels of H3K9 methylation. Ccq1, a subunit of shelterin, protects TAS from nucleosome loss by recruiting the heterochromatic repressor complexes CLRC and SHREC, thereby linking nucleosome stability to gene silencing. Nucleosome instability at TAS is independent of telomeric repeats and can be transmitted to an intrachromosomal locus containing an ectopic TAS fragment, indicating that this is an intrinsic property of the underlying DNA sequence. When telomerase recruitment is compromised in cells lacking Ccq1, DNA sequences present in the TAS promote recombination between chromosomal ends, independent of nucleosome abundance, implying an active function of these sequences in telomere maintenance. We propose that Ccq1 and fragile subtelomeres co-evolved to regulate telomere plasticity by controlling nucleosome occupancy and genome stability.
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Affiliation(s)
- Thomas S van Emden
- Department of Physiological Chemistry, BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany.,International Max Planck Research School for Molecular and Cellular Life Sciences, Martinsried, Germany
| | - Marta Forn
- Department of Physiological Chemistry, BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany
| | - Ignasi Forné
- Protein Analysis Unit (ZfP), BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany
| | - Zsuzsa Sarkadi
- Department of Physiological Chemistry, BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany
| | - Matías Capella
- Department of Physiological Chemistry, BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany
| | - Lucía Martín Caballero
- Department of Physiological Chemistry, BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany.,International Max Planck Research School for Molecular and Cellular Life Sciences, Martinsried, Germany
| | - Sabine Fischer-Burkart
- Department of Physiological Chemistry, BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany
| | - Cornelia Brönner
- Department of Biochemistry, Gene Center, Ludwig Maximilians University of Munich, Munich, Germany
| | - Marco Simonetta
- Department of Biophysics and Biochemistry, University of California San Francisco (UCSF), San Francisco, CA, USA
| | - David Toczyski
- Department of Biophysics and Biochemistry, University of California San Francisco (UCSF), San Francisco, CA, USA
| | - Mario Halic
- Department of Biochemistry, Gene Center, Ludwig Maximilians University of Munich, Munich, Germany
| | - Axel Imhof
- Protein Analysis Unit (ZfP), BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany
| | - Sigurd Braun
- Department of Physiological Chemistry, BioMedical Center (BMC), Ludwig Maximilians University of Munich, Martinsried, Germany .,International Max Planck Research School for Molecular and Cellular Life Sciences, Martinsried, Germany
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22
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Tanna M, Aqeilan RI. Modeling WWOX Loss of Function in vivo: What Have We Learned? Front Oncol 2018; 8:420. [PMID: 30370248 PMCID: PMC6194312 DOI: 10.3389/fonc.2018.00420] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/10/2018] [Indexed: 12/21/2022] Open
Abstract
The WW domain–containing oxidoreductase (WWOX) gene encompasses a common fragile sites (CFS) known as FRA16D, and is implicated in cancer. WWOX encodes a 46kDa adaptor protein, which contains two N-terminal WW–domains and a catalytic domain at its C–terminus homologous to short–chain dehydrogenase/reductase (SDR) family proteins. A high sequence conservation of WWOX orthologues from insects to rodents and ultimately humans suggest its significant role in physiology and homeostasis. Indeed, data obtained from several animal models including flies, fish, and rodents demonstrate WWOX in vivo requirement and that its deregulation results in severe pathological consequences including growth retardation, post–natal lethality, neuropathy, metabolic disorders, and tumorigenesis. Altogether, these findings set WWOX as an essential protein that is necessary to maintain normal cellular/physiological homeostasis. Here, we review and discuss lessons and outcomes learned from modeling loss of WWOX expression in vivo.
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Affiliation(s)
- Mayur Tanna
- Faculty of Medicine, The Lautenberg Center for Immunology and Cancer Research, Institute for Medical Research, Israel-Canada (IMRIC), Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rami I Aqeilan
- Faculty of Medicine, The Lautenberg Center for Immunology and Cancer Research, Institute for Medical Research, Israel-Canada (IMRIC), Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Cancer Biology & Genetics, Ohio State University Wexner Medical Center, Columbus, OH, United States
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23
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Cancer evolution, mutations, and clonal selection in relapse neuroblastoma. Cell Tissue Res 2018; 372:263-268. [DOI: 10.1007/s00441-018-2810-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 01/24/2018] [Indexed: 12/11/2022]
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24
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Kretschmer R, de Oliveira TD, de Oliveira Furo I, Oliveira Silva FA, Gunski RJ, Del Valle Garnero A, de Bello Cioffi M, de Oliveira EHC, de Freitas TRO. Repetitive DNAs and shrink genomes: A chromosomal analysis in nine Columbidae species (Aves, Columbiformes). Genet Mol Biol 2018; 41:98-106. [PMID: 29473932 PMCID: PMC5901494 DOI: 10.1590/1678-4685-gmb-2017-0048] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 08/16/2017] [Indexed: 12/02/2022] Open
Abstract
An extensive karyotype variation is found among species belonging to the
Columbidae family of birds (Columbiformes), both in diploid number and
chromosomal morphology. Although clusters of repetitive DNA sequences play an
important role in chromosomal instability, and therefore in chromosomal
rearrangements, little is known about their distribution and amount in avian
genomes. The aim of this study was to analyze the distribution of 11 distinct
microsatellite sequences, as well as clusters of 18S rDNA, in nine different
Columbidae species, correlating their distribution with the occurrence of
chromosomal rearrangements. We found 2n values ranging from 76 to 86 and nine
out of 11 microsatellite sequences showed distinct hybridization signals among
the analyzed species. The accumulation of microsatellite repeats was found
preferentially in the centromeric region of macro and microchromosomes, and in
the W chromosome. Additionally, pair 2 showed the accumulation of several
microsatellites in different combinations and locations in the distinct species,
suggesting the occurrence of intrachromosomal rearrangements, as well as a
possible fission of this pair in Geotrygon species. Therefore,
although birds have a smaller amount of repetitive sequences when compared to
other Tetrapoda, these seem to play an important role in the karyotype evolution
of these species.
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Affiliation(s)
- Rafael Kretschmer
- Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, RS, Brazil
| | - Thays Duarte de Oliveira
- Programa de Pós-Graduação em Ciências Biológicas, PPGCB, Universidade Federal do Pampa, São Gabriel, Rio Grande do Sul, RS, Brazil
| | - Ivanete de Oliveira Furo
- Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Universidade Federal do Pará, Belém, PA, Brazil
| | | | - Ricardo José Gunski
- Programa de Pós-Graduação em Ciências Biológicas, PPGCB, Universidade Federal do Pampa, São Gabriel, Rio Grande do Sul, RS, Brazil
| | - Analía Del Valle Garnero
- Programa de Pós-Graduação em Ciências Biológicas, PPGCB, Universidade Federal do Pampa, São Gabriel, Rio Grande do Sul, RS, Brazil
| | - Marcelo de Bello Cioffi
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brazil
| | - Edivaldo Herculano Corrêa de Oliveira
- Instituto de Ciências Exatas e Naturais, Universidade Federal do Pará, Belém, PA, Brazil.,Laboratório de Cultura de Tecidos e Citogenética, SAMAM, Instituto Evandro Chagas, Ananindeua, PA, Brazil
| | - Thales Renato Ochotorena de Freitas
- Programa de Pós-Graduação em Genética e Biologia Molecular, PPGBM, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, RS, Brazil
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25
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DNA Replication Control During Drosophila Development: Insights into the Onset of S Phase, Replication Initiation, and Fork Progression. Genetics 2017; 207:29-47. [PMID: 28874453 PMCID: PMC5586379 DOI: 10.1534/genetics.115.186627] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 05/19/2017] [Indexed: 12/11/2022] Open
Abstract
Proper control of DNA replication is critical to ensure genomic integrity during cell proliferation. In addition, differential regulation of the DNA replication program during development can change gene copy number to influence cell size and gene expression. Drosophila melanogaster serves as a powerful organism to study the developmental control of DNA replication in various cell cycle contexts in a variety of differentiated cell and tissue types. Additionally, Drosophila has provided several developmentally regulated replication models to dissect the molecular mechanisms that underlie replication-based copy number changes in the genome, which include differential underreplication and gene amplification. Here, we review key findings and our current understanding of the developmental control of DNA replication in the contexts of the archetypal replication program as well as of underreplication and differential gene amplification. We focus on the use of these latter two replication systems to delineate many of the molecular mechanisms that underlie the developmental control of replication initiation and fork elongation.
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26
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Chastain M, Zhou Q, Shiva O, Fadri-Moskwik M, Whitmore L, Jia P, Dai X, Huang C, Ye P, Chai W. Human CST Facilitates Genome-wide RAD51 Recruitment to GC-Rich Repetitive Sequences in Response to Replication Stress. Cell Rep 2017; 16:1300-1314. [PMID: 27487043 DOI: 10.1016/j.celrep.2016.06.077] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 05/23/2016] [Accepted: 06/17/2016] [Indexed: 11/25/2022] Open
Abstract
The telomeric CTC1/STN1/TEN1 (CST) complex has been implicated in promoting replication recovery under replication stress at genomic regions, yet its precise role is unclear. Here, we report that STN1 is enriched at GC-rich repetitive sequences genome-wide in response to hydroxyurea (HU)-induced replication stress. STN1 deficiency exacerbates the fragility of these sequences under replication stress, resulting in chromosome fragmentation. We find that upon fork stalling, CST proteins form distinct nuclear foci that colocalize with RAD51. Furthermore, replication stress induces physical association of CST with RAD51 in an ATR-dependent manner. Strikingly, CST deficiency diminishes HU-induced RAD51 foci formation and reduces RAD51 recruitment to telomeres and non-telomeric GC-rich fragile sequences. Collectively, our findings establish that CST promotes RAD51 recruitment to GC-rich repetitive sequences in response to replication stress to facilitate replication restart, thereby providing insights into the mechanism underlying genome stability maintenance.
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Affiliation(s)
- Megan Chastain
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99210, USA
| | - Qing Zhou
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99210, USA
| | - Olga Shiva
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99210, USA
| | - Maria Fadri-Moskwik
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99210, USA
| | - Leanne Whitmore
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA
| | - Pingping Jia
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99210, USA
| | - Xueyu Dai
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99210, USA
| | - Chenhui Huang
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99210, USA
| | - Ping Ye
- Department of Molecular and Experimental Medicine, Avera Cancer Institute, 1000 E 23rd Street, Suite 370, Sioux Falls, SD 57105, USA; Department of Pharmacy Practice, South Dakota State University, Brookings, SD 57007, USA
| | - Weihang Chai
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA 99210, USA.
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27
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Irony-Tur Sinai M, Kerem B. DNA replication stress drives fragile site instability. Mutat Res 2017; 808:56-61. [PMID: 29074228 DOI: 10.1016/j.mrfmmm.2017.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/26/2017] [Accepted: 10/12/2017] [Indexed: 12/21/2022]
Abstract
DNA replication stress is one of the early drivers enabling the ongoing acquisition of genetic changes arising during tumorigenesis. As such, it is a feature of most pre-malignant and malignant cells. In this review article, we focus on the early events initiating DNA replication stress and the preferential sensitivity of common fragile sites (CFSs) to this stress. CFSs are specific genomic regions within the normal chromosomal structure, which appear as gaps and breaks in the metaphase chromosomes of cells grown under mild replication stress conditions. The main characteristics predisposing CFSs to instability include late replication timing, delayed replication completion, failure to activate additional origins, origin paucity along large genomic regions, collision between replication and transcription complexes along large genes, and the presence of AT-dinucleotide rich sequences. The contribution of these features to instability at CFSs during early cancer development is discussed.
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Affiliation(s)
- Michal Irony-Tur Sinai
- Department of Genetics, The Life Sciences Institute, The Hebrew University, Jerusalem, 91904, Israel
| | - Batsheva Kerem
- Department of Genetics, The Life Sciences Institute, The Hebrew University, Jerusalem, 91904, Israel.
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28
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Bournique E, Dall'Osto M, Hoffmann JS, Bergoglio V. Role of specialized DNA polymerases in the limitation of replicative stress and DNA damage transmission. Mutat Res 2017; 808:62-73. [PMID: 28843435 DOI: 10.1016/j.mrfmmm.2017.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/08/2017] [Accepted: 08/09/2017] [Indexed: 01/31/2023]
Abstract
Replication stress is a strong and early driving force for genomic instability and tumor development. Beside replicative DNA polymerases, an emerging group of specialized DNA polymerases is involved in the technical assistance of the replication machinery in order to prevent replicative stress and its deleterious consequences. During S-phase, altered progression of the replication fork by endogenous or exogenous impediments induces replicative stress, causing cells to reach mitosis with genomic regions not fully duplicated. Recently, specific mechanisms to resolve replication intermediates during mitosis with the aim of limiting DNA damage transmission to daughter cells have been identified. In this review, we detail the two major actions of specialized DNA polymerases that limit DNA damage transmission: the prevention of replicative stress by non-B DNA replication and the recovery of stalled replication forks.
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Affiliation(s)
- Elodie Bournique
- CRCT, Université de Toulouse, Inserm, CNRS, UPS Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, 2 Avenue Hubert Curien, 31037, Toulouse, France
| | - Marina Dall'Osto
- CRCT, Université de Toulouse, Inserm, CNRS, UPS Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, 2 Avenue Hubert Curien, 31037, Toulouse, France
| | - Jean-Sébastien Hoffmann
- CRCT, Université de Toulouse, Inserm, CNRS, UPS Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, 2 Avenue Hubert Curien, 31037, Toulouse, France
| | - Valérie Bergoglio
- CRCT, Université de Toulouse, Inserm, CNRS, UPS Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, 2 Avenue Hubert Curien, 31037, Toulouse, France.
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29
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Evaluation of Structural Factors Potentially Implicated in Acute Lymphoblastic Leukemia: A report of the MIGICCL. Arch Med Res 2017; 47:515-520. [PMID: 28262192 DOI: 10.1016/j.arcmed.2016.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/23/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND AIMS Acute lymphoblastic leukemia (ALL) is the most common cancer in the pediatric population; ∼80% of the cases show some translocation. Translocations that result in ALL are due to chromosome breaks. However, the exact mechanisms that cause these breaks have not been well studied. A detailed search of the breakpoints associated with ALL reported in the NCBI database shows that some are concentrated in limited regions of the chromosome, whereas others are scattered throughout. Therefore, the objective of this study was to identify the structural factors involved in chromosomal breaks in ALL. METHODS We performed several bioinformatic studies on the sequences where chromosomal breakpoints have been reported in search of rearrangements: areas of high similarity, thermodynamic stability, composition and conformation of the DNA. RESULTS Certain factors may influence chromosome breaks and are capable of predicting the propensity towards these types of events. CONCLUSIONS These findings may be useful in the design of molecular techniques able to detect these changes in ALL.
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30
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Madireddy A, Gerhardt J. Replication Through Repetitive DNA Elements and Their Role in Human Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1042:549-581. [PMID: 29357073 DOI: 10.1007/978-981-10-6955-0_23] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Human cells contain various repetitive DNA sequences, which can be a challenge for the DNA replication machinery to travel through and replicate correctly. Repetitive DNA sequence can adopt non-B DNA structures, which could block the DNA replication. Prolonged stalling of the replication fork at the endogenous repeats in human cells can have severe consequences such as genome instability that includes repeat expansions, contractions, and chromosome fragility. Several neurological and muscular diseases are caused by a repeat expansion. Furthermore genome instability is the major cause of cancer. This chapter describes some of the important classes of repetitive DNA sequences in the mammalian genome, their ability to form secondary DNA structures, their contribution to replication fork stalling, and models for repeat expansion as well as chromosomal fragility. Included in this chapter are also some of the strategies currently employed to detect changes in DNA replication and proteins that could prevent the repeat-mediated disruption of DNA replication in human cells. Additionally summarized are the consequences of repeat-associated perturbation of the DNA replication, which could lead to specific human diseases.
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31
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Feng W, Chakraborty A. Fragility Extraordinaire: Unsolved Mysteries of Chromosome Fragile Sites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1042:489-526. [PMID: 29357071 DOI: 10.1007/978-981-10-6955-0_21] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Chromosome fragile sites are a fascinating cytogenetic phenomenon now widely implicated in a slew of human diseases ranging from neurological disorders to cancer. Yet, the paths leading to these revelations were far from direct, and the number of fragile sites that have been molecularly cloned with known disease-associated genes remains modest. Moreover, as more fragile sites were being discovered, research interests in some of the earliest discovered fragile sites ebbed away, leaving a number of unsolved mysteries in chromosome biology. In this review we attempt to recount some of the early discoveries of fragile sites and highlight those phenomena that have eluded intense scrutiny but remain extremely relevant in our understanding of the mechanisms of chromosome fragility. We then survey the literature for disease association for a comprehensive list of fragile sites. We also review recent studies addressing the underlying cause of chromosome fragility while highlighting some ongoing debates. We report an observed enrichment for R-loop forming sequences in fragile site-associated genes than genomic average. Finally, we will leave the reader with some lingering questions to provoke discussion and inspire further scientific inquiries.
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Affiliation(s)
- Wenyi Feng
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA.
| | - Arijita Chakraborty
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
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32
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Beresova L, Vesela E, Chamrad I, Voller J, Yamada M, Furst T, Lenobel R, Chroma K, Gursky J, Krizova K, Mistrik M, Bartek J. Role of DNA Repair Factor Xeroderma Pigmentosum Protein Group C in Response to Replication Stress As Revealed by DNA Fragile Site Affinity Chromatography and Quantitative Proteomics. J Proteome Res 2016; 15:4505-4517. [PMID: 27794614 DOI: 10.1021/acs.jproteome.6b00622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Replication stress (RS) fuels genomic instability and cancer development and may contribute to aging, raising the need to identify factors involved in cellular responses to such stress. Here, we present a strategy for identification of factors affecting the maintenance of common fragile sites (CFSs), which are genomic loci that are particularly sensitive to RS and suffer from increased breakage and rearrangements in tumors. A DNA probe designed to match the high flexibility island sequence typical for the commonly expressed CFS (FRA16D) was used as specific DNA affinity bait. Proteins significantly enriched at the FRA16D fragment under normal and replication stress conditions were identified using stable isotope labeling of amino acids in cell culture-based quantitative mass spectrometry. The identified proteins interacting with the FRA16D fragment included some known CFS stabilizers, thereby validating this screening approach. Among the hits from our screen so far not implicated in CFS maintenance, we chose Xeroderma pigmentosum protein group C (XPC) for further characterization. XPC is a key factor in the DNA repair pathway known as global genomic nucleotide excision repair (GG-NER), a mechanism whose several components were enriched at the FRA16D fragment in our screen. Functional experiments revealed defective checkpoint signaling and escape of DNA replication intermediates into mitosis and the next generation of XPC-depleted cells exposed to RS. Overall, our results provide insights into an unexpected biological role of XPC in response to replication stress and document the power of proteomics-based screening strategies to elucidate mechanisms of pathophysiological significance.
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Affiliation(s)
- Lucie Beresova
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic.,Department of Protein Biochemistry and Proteomics, Centre of the Region Hana for Biotechnological and Agricultural Research, Faculty of Science, Palacky University , Olomouc, Czech Republic
| | - Eva Vesela
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic
| | - Ivo Chamrad
- Department of Protein Biochemistry and Proteomics, Centre of the Region Hana for Biotechnological and Agricultural Research, Faculty of Science, Palacky University , Olomouc, Czech Republic
| | - Jiri Voller
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic
| | - Masayuki Yamada
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic
| | - Tomas Furst
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic
| | - Rene Lenobel
- Department of Protein Biochemistry and Proteomics, Centre of the Region Hana for Biotechnological and Agricultural Research, Faculty of Science, Palacky University , Olomouc, Czech Republic
| | - Katarina Chroma
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic
| | - Jan Gursky
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic
| | - Katerina Krizova
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic
| | - Martin Mistrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic
| | - Jiri Bartek
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University , Olomouc, Czech Republic.,Danish Cancer Society Research Center , Copenhagen, Denmark.,Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Biochemistry and Biophysics, Karolinska Institute , Stockholm, Sweden
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Gao G, Johnson SH, Vasmatzis G, Pauley CE, Tombers NM, Kasperbauer JL, Smith DI. Common fragile sites (CFS) and extremely large CFS genes are targets for human papillomavirus integrations and chromosome rearrangements in oropharyngeal squamous cell carcinoma. Genes Chromosomes Cancer 2016; 56:59-74. [PMID: 27636103 DOI: 10.1002/gcc.22415] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 09/12/2016] [Accepted: 09/13/2016] [Indexed: 01/04/2023] Open
Abstract
Common fragile sites (CFS) are chromosome regions that are prone to form gaps or breaks in response to DNA replication stress. They are often found as hotspots for sister chromatid exchanges, deletions, and amplifications in different cancers. Many of the CFS regions are found to span genes whose genomic sequence is greater than 1 Mb, some of which have been demonstrated to function as important tumor suppressors. CFS regions are also hotspots for human papillomavirus (HPV) integrations in cervical cancer. We used mate-pair sequencing to examine HPV integration events and chromosomal structural variations in 34 oropharyngeal squamous cell carcinoma (OPSCC). We used endpoint PCR and Sanger sequencing to validate each HPV integration event and found HPV integrations preferentially occurred within CFS regions similar to what is observed in cervical cancer. We also found that many of the chromosomal alterations detected also occurred at or near the cytogenetic location of CFSs. Several large genes were also found to be recurrent targets of rearrangements, independent of HPV integrations, including CSMD1 (2.1Mb), LRP1B (1.9Mb), and LARGE1 (0.7Mb). Sanger sequencing revealed that the nucleotide sequences near to identified junction sites contained repetitive and AT-rich sequences that were shown to have the potential to form stem-loop DNA secondary structures that might stall DNA replication fork progression during replication stress. This could then cause increased instability in these regions which could lead to cancer development in human cells. Our findings suggest that CFSs and some specific large genes appear to play important roles in OPSCC. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ge Gao
- Division of Experimental Pathology, Mayo Clinic, Rochester, MN
| | - Sarah H Johnson
- Biomarker Discovery Program, Center for Individualized Medicine, Mayo Clinic, Rochester, MN
| | - George Vasmatzis
- Biomarker Discovery Program, Center for Individualized Medicine, Mayo Clinic, Rochester, MN
| | | | | | | | - David I Smith
- Division of Experimental Pathology, Mayo Clinic, Rochester, MN
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Superresolution intrinsic fluorescence imaging of chromatin utilizing native, unmodified nucleic acids for contrast. Proc Natl Acad Sci U S A 2016; 113:9716-21. [PMID: 27535934 DOI: 10.1073/pnas.1602202113] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Visualizing the nanoscale intracellular structures formed by nucleic acids, such as chromatin, in nonperturbed, structurally and dynamically complex cellular systems, will help expand our understanding of biological processes and open the next frontier for biological discovery. Traditional superresolution techniques to visualize subdiffractional macromolecular structures formed by nucleic acids require exogenous labels that may perturb cell function and change the very molecular processes they intend to study, especially at the extremely high label densities required for superresolution. However, despite tremendous interest and demonstrated need, label-free optical superresolution imaging of nucleotide topology under native nonperturbing conditions has never been possible. Here we investigate a photoswitching process of native nucleotides and present the demonstration of subdiffraction-resolution imaging of cellular structures using intrinsic contrast from unmodified DNA based on the principle of single-molecule photon localization microscopy (PLM). Using DNA-PLM, we achieved nanoscopic imaging of interphase nuclei and mitotic chromosomes, allowing a quantitative analysis of the DNA occupancy level and a subdiffractional analysis of the chromosomal organization. This study may pave a new way for label-free superresolution nanoscopic imaging of macromolecular structures with nucleotide topologies and could contribute to the development of new DNA-based contrast agents for superresolution imaging.
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Integration of HIV in the Human Genome: Which Sites Are Preferential? A Genetic and Statistical Assessment. Int J Genomics 2016; 2016:2168590. [PMID: 27294106 PMCID: PMC4880676 DOI: 10.1155/2016/2168590] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/24/2016] [Indexed: 12/17/2022] Open
Abstract
Chromosomal fragile sites (FSs) are loci where gaps and breaks may occur and are preferential integration targets for some viruses, for example, Hepatitis B, Epstein-Barr virus, HPV16, HPV18, and MLV vectors. However, the integration of the human immunodeficiency virus (HIV) in Giemsa bands and in FSs is not yet completely clear. This study aimed to assess the integration preferences of HIV in FSs and in Giemsa bands using an in silico study. HIV integration positions from Jurkat cells were used and two nonparametric tests were applied to compare HIV integration in dark versus light bands and in FS versus non-FS (NFSs). The results show that light bands are preferential targets for integration of HIV-1 in Jurkat cells and also that it integrates with equal intensity in FSs and in NFSs. The data indicates that HIV displays different preferences for FSs compared to other viruses. The aim was to develop and apply an approach to predict the conditions and constraints of HIV insertion in the human genome which seems to adequately complement empirical data.
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Kumar Y, Yang J, Hu T, Chen L, Xu Z, Xu L, Hu XX, Tang G, Wang JM, Li Y, Poon WS, Wan W, Zhang L, Mat WK, Pun FW, Lee P, Cheong THY, Ding X, Ng SK, Tsang SY, Chen JF, Zhang P, Li S, Wang HY, Xue H. Massive interstitial copy-neutral loss-of-heterozygosity as evidence for cancer being a disease of the DNA-damage response. BMC Med Genomics 2015. [PMID: 26208496 PMCID: PMC4515014 DOI: 10.1186/s12920-015-0104-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background The presence of loss-of-heterozygosity (LOH) mutations in cancer cell genomes is commonly encountered. Moreover, the occurrences of LOHs in tumor suppressor genes play important roles in oncogenesis. However, because the causative mechanisms underlying LOH mutations in cancer cells yet remain to be elucidated, enquiry into the nature of these mechanisms based on a comprehensive examination of the characteristics of LOHs in multiple types of cancers has become a necessity. Methods We performed next-generation sequencing on inter-Alu sequences of five different types of solid tumors and acute myeloid leukemias, employing the AluScan platform which entailed amplification of such sequences using multiple PCR primers based on the consensus sequences of Alu elements; as well as the whole genome sequences of a lung-to-liver metastatic cancer and a primary liver cancer. Paired-end sequencing reads were aligned to the reference human genome to identify major and minor alleles so that the partition of LOH products between homozygous-major vs. homozygous-minor alleles could be determined at single-base resolution. Strict filtering conditions were employed to avoid false positives. Measurements of LOH occurrences in copy number variation (CNV)-neutral regions were obtained through removal of CNV-associated LOHs. Results We found: (a) average occurrence of copy-neutral LOHs amounting to 6.9 % of heterologous loci in the various cancers; (b) the mainly interstitial nature of the LOHs; and (c) preference for formation of homozygous-major over homozygous-minor, and transitional over transversional, LOHs. Conclusions The characteristics of the cancer LOHs, observed in both AluScan and whole genome sequencings, point to the formation of LOHs through repair of double-strand breaks by interhomolog recombination, or gene conversion, as the consequence of a defective DNA-damage response, leading to a unified mechanism for generating the mutations required for oncogenesis as well as the progression of cancer cells. Electronic supplementary material The online version of this article (doi:10.1186/s12920-015-0104-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yogesh Kumar
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Jianfeng Yang
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Taobo Hu
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Lei Chen
- Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China.
| | - Zhi Xu
- Department of Oncology, Nanjing First Hospital, and Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.
| | - Lin Xu
- Jiangsu Key Laboratory of Cancer Molecular Biology and Translational Medicine, Jiangsu Cancer Hospital, Nanjing, China.
| | - Xiao-Xia Hu
- Department of Hematology, Changhai Hospital, Second Military Medical University, Shanghai, China.
| | - Gusheng Tang
- Department of Hematology, Changhai Hospital, Second Military Medical University, Shanghai, China.
| | - Jian-Min Wang
- Department of Hematology, Changhai Hospital, Second Military Medical University, Shanghai, China.
| | - Yi Li
- Department of Surgery, The Chinese University of Hong Kong, Hong Kong, China.
| | - Wai-Sang Poon
- Department of Surgery, The Chinese University of Hong Kong, Hong Kong, China.
| | - Weiqing Wan
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, 6 Tiantan Xili, Dongcheng District, Beijing, 100050, China.
| | - Liwei Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, 6 Tiantan Xili, Dongcheng District, Beijing, 100050, China.
| | - Wai-Kin Mat
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Frank W Pun
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Peggy Lee
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Timothy H Y Cheong
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Xiaofan Ding
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Siu-Kin Ng
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Shui-Ying Tsang
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
| | - Jin-Fei Chen
- Department of Oncology, Nanjing First Hospital, and Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China.
| | - Peng Zhang
- MOE Key Laboratory of Bioinformatics and Bioinformatics Division, TNLIST, and Department of Automation, Tsinghua University, Beijing, 100084, China.
| | - Shao Li
- MOE Key Laboratory of Bioinformatics and Bioinformatics Division, TNLIST, and Department of Automation, Tsinghua University, Beijing, 100084, China.
| | - Hong-Yang Wang
- Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China.
| | - Hong Xue
- Division of Life Science, Applied Genomics Centre and Centre for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
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Miron K, Golan-Lev T, Dvir R, Ben-David E, Kerem B. Oncogenes create a unique landscape of fragile sites. Nat Commun 2015; 6:7094. [DOI: 10.1038/ncomms8094] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 04/02/2015] [Indexed: 11/09/2022] Open
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Abstract
WWOX, the WW domain-containing oxidoreductase gene at chromosome region 16q23.3-q24.1, spanning chromosomal fragile site FRA16D, encodes the 46 kDa Wwox protein, a tumor suppressor that is lost or reduced in expression in a wide variety of cancers, including breast, prostate, ovarian, and lung. The function of Wwox as a tumor suppressor implies that it serves a function in the prevention of carcinogenesis. Indeed, in vitro studies show that Wwox protein interacts with many binding partners to regulate cellular apoptosis, proliferation, and/or maturation. It has been reported that newborn Wwox knockout mice exhibit nascent osteosarcomas while Wwox(+/-) mice exhibit increased incidence of spontaneous and induced tumors. Furthermore, absence or reduction of Wwox expression in mouse xenograft models results in increased tumorigenesis, which can be rescued by Wwox re-expression, though there is not universal agreement among investigators regarding the role of Wwox loss in these experimental models. Despite this proposed tumor suppressor function, the overlap of the human WWOX locus with FRA16D sensitizes the gene to protein-inactivating deletions caused by replication stress. The high frequency of deletions within the WWOX locus in cancers of various types, without the hallmark protein inactivation-associated mutations of "classical" tumor suppressors, has led to the proposal that WWOX deletions in cancers are passenger events that occur in early cancer progenitor cells due to fragility of the genetic locus, rather than driver events which provide the cancer cell a selective advantage. Recently, a proposed epigenetic cause of chromosomal fragility has suggested a novel mechanism for early fragile site instability and has implications regarding the involvement of tumor suppressor genes at chromosomal fragile sites in cancer. In this review, we provide an overview of the evidence for WWOX as a tumor suppressor gene and put this into the context of fragility associated with the FRA16D locus.
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Affiliation(s)
- Morgan S Schrock
- Biomedical Sciences Graduate Program, Ohio State University Wexner Medical Center, Columbus, Ohio 43210, USA Department of Molecular Virology, Immunology and Medical Genetics, Comprehensive Cancer Center, Ohio State University Wexner Medical Center, Columbus, Ohio 43210, USA
| | - Kay Huebner
- Department of Molecular Virology, Immunology and Medical Genetics, Comprehensive Cancer Center, Ohio State University Wexner Medical Center, Columbus, Ohio 43210, USA
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Owen N, Hejna J, Rennie S, Mitchell A, Newell AH, Ziaie N, Moses RE, Olson SB. Bloom syndrome radials are predominantly non-homologous and are suppressed by phosphorylated BLM. Cytogenet Genome Res 2015; 144:255-263. [PMID: 25766002 DOI: 10.1159/000375247] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2014] [Indexed: 01/01/2023] Open
Abstract
Biallelic mutations in BLM cause Bloom syndrome (BS), a genome instability disorder characterized by growth retardation, sun sensitivity and a predisposition to cancer. As evidence of decreased genome stability, BS cells demonstrate not only elevated levels of spontaneous sister chromatid exchanges (SCEs), but also exhibit chromosomal radial formation. The molecular nature and mechanism of radial formation is not known, but radials have been thought to be DNA recombination intermediates between homologs that failed to resolve. However, we find that radials in BS cells occur over 95% between non-homologous chromosomes, and occur non-randomly throughout the genome. BLM must be phosphorylated at T99 and T122 for certain cell cycle checkpoints, but it is not known whether these modifications are necessary to suppress radial formation. We find that exogenous BLM constructs preventing phosphorylation at T99 and T122 are not able to suppress radial formation in BS cells, but are able to inhibit SCE formation. These findings indicate that BLM functions in 2 distinct pathways requiring different modifications. In one pathway, for which the phosphorylation marks appear dispensable, BLM functions to suppress SCE formation. In a second pathway, T99 and T122 phosphorylations are essential for suppression of chromosomal radial formation, both those formed spontaneously and those formed following interstrand crosslink damage.
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Affiliation(s)
- Nichole Owen
- Department of Molecular and Medical Genetics Oregon Health & Science University, 3181 SW Sam Jackson Park, Portland, OR 97239
| | - James Hejna
- Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8501 Japan
| | - Scott Rennie
- Department of Molecular and Medical Genetics Oregon Health & Science University, 3181 SW Sam Jackson Park, Portland, OR 97239
| | - Asia Mitchell
- Department of Molecular and Medical Genetics Oregon Health & Science University, 3181 SW Sam Jackson Park, Portland, OR 97239
| | - Amy Hanlon Newell
- Department of Molecular and Medical Genetics Oregon Health & Science University, 3181 SW Sam Jackson Park, Portland, OR 97239
| | - Navid Ziaie
- Department of Molecular and Medical Genetics Oregon Health & Science University, 3181 SW Sam Jackson Park, Portland, OR 97239
| | - Robb E Moses
- Department of Molecular and Cellular Biology, Baylor College of Medicine Houston, TX 77030
| | - Susan B Olson
- Department of Molecular and Medical Genetics Oregon Health & Science University, 3181 SW Sam Jackson Park, Portland, OR 97239
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Murphy SJ, Wigle DA, Lima JF, Harris FR, Johnson SH, Halling G, Asiedu MK, Seto CT, Terra S, Kosari F, Peikert T, Yang P, Aubry MC, Vasmatzis G. Genomic rearrangements define lineage relationships between adjacent lepidic and invasive components in lung adenocarcinoma. Cancer Res 2014; 74:3157-67. [PMID: 24879567 DOI: 10.1158/0008-5472.can-13-1727] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The development of adenocarcinoma of the lung is believed to proceed from in situ disease (adenocarcinoma in situ, AIS) to minimally invasive disease with prominent lepidic growth (minimally invasive adenocarcinoma, MIA), then to fully invasive adenocarcinoma (AD), but direct evidence for this model has been lacking. Because some lung adenocarcinomas show prominent lepidic growth (AD-L), we designed a study to address the lineage relationship between the lepidic (noninvasive) component (L) and the adjacent nonlepidic growth component representing invasive disease within individual tumors. Lineage relationships were evaluated by next-generation DNA sequencing to define large genomic rearrangements in microdissected tissue specimens collected by laser capture. We found a strong lineage relationship between the majority of adjacent lepidic and invasive components, supporting a putative AIS-AD transition. Notably, many rearrangements were detected in the less aggressive lepidic component, although the invasive component exhibited an overall higher rate of genomic rearrangement. Furthermore, a significant number of genomic rearrangements were present in histologically normal lung adjacent to tumor, but not in host germline DNA, suggesting field defects restricted to zonal regions near a tumor. Our results offer a perspective on the genetic pathogenesis underlying adenocarcinoma development and its clinical management.
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Affiliation(s)
- Stephen J Murphy
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Dennis A Wigle
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Joema Felipe Lima
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Faye R Harris
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Sarah H Johnson
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Geoffrey Halling
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Michael K Asiedu
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Charlie T Seto
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Simone Terra
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Farhad Kosari
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Tobias Peikert
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Ping Yang
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MinnesotaAuthors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Marie-Christine Aubry
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - George Vasmatzis
- Authors' Affiliations: Departments of Molecular Medicine, General Thoracic Surgery, Pulmonary and Critical Care Medicine, Health Sciences Research, and Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
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41
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Wójcik E, Andraszek K, Smalec E, Knaga S, Witkowski A. Identification of chromosome instability in Japanese quail (Coturnix japonica). Br Poult Sci 2014; 55:435-41. [PMID: 24898539 DOI: 10.1080/00071668.2014.929637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
1. A study of the incidence of chromosome instability in the Japanese quail as assessed by sister chromatid exchange (SCE) and fragile site identification in chromosomes was conducted in two parent breeds and their F1 and F2 generations. 2. The mean incidence of SCEs was 6.02 ± 0.45 and the frequency of fragile sites was 1.17 ± 0.79. 3. There were moderately negative correlations of 0.51-0.64 between chromosome instability and fertility in the F1 and 0.10-0.23 in the F2. The hatch of fertilised eggs was negatively correlated with the number of SCE in male (0.31) and female (0.33) F1 and was lower in P (0.18 and 0.19, respectively), whereas the correlations were similar for the number of fragile sites in both generations (0.51-0.62).
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Affiliation(s)
- E Wójcik
- a Department of Animal Genetics and Horse Breeding , Siedlce University of Natural Sciences and Humanities , Siedlce , Poland
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42
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A high resolution map of mammalian X chromosome fragile regions assessed by large-scale comparative genomics. Mamm Genome 2014; 25:618-35. [PMID: 25086724 DOI: 10.1007/s00335-014-9537-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 07/14/2014] [Indexed: 10/24/2022]
Abstract
Chromosomal evolution involves multiple changes at structural and numerical levels. These changes, which are related to the variation of the gene number and their location, can be tracked by the identification of syntenic blocks (SB). First reports proposed that ~180-280 SB might be shared by mouse and human species. More recently, further studies including additional genomes have identified up to ~1,400 SB during the evolution of eutherian species. A considerable number of studies regarding the X chromosome's structure and evolution have been undertaken because of its extraordinary biological impact on reproductive fitness and speciation. Some have identified evolutionary breakpoint regions and fragile sites at specific locations in the human X chromosome. However, mapping these regions to date has involved using low-to-moderate resolution techniques. Such scenario might be related to underestimating their total number and giving an inaccurate location. The present study included using a combination of bioinformatics methods for identifying, at base-pair level, chromosomal rearrangements occurring during X chromosome evolution in 13 mammalian species. A comparative technique using four different algorithms was used for optimizing the detection of hotspot regions in the human X chromosome. We identified a significant interspecific variation in SB size which was related to genetic information gain regarding the human X chromosome. We found that human hotspot regions were enriched by LINE-1 and Alu transposable elements, which may have led to intraspecific chromosome rearrangement events. New fragile regions located in the human X chromosome have also been postulated. We estimate that the high resolution map of X chromosome fragile sites presented here constitutes useful data concerning future studies on mammalian evolution and human disease.
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43
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Weissbein U, Benvenisty N, Ben-David U. Quality control: Genome maintenance in pluripotent stem cells. ACTA ACUST UNITED AC 2014; 204:153-63. [PMID: 24446481 PMCID: PMC3897183 DOI: 10.1083/jcb.201310135] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Pluripotent stem cells (PSCs) must maintain their proper genomic content in order to preserve appropriate self-renewal and differentiation capacities. However, their prolonged in vitro propagation, as well as the environmental culture conditions, present serious challenges to genome maintenance. Recent work has been focused on potential means to alleviate the genomic insults experienced by PSCs, and to detect them as soon as they arise, in order to prevent the detrimental consequences of these genomic aberrations on PSC application in basic research and regenerative medicine.
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Affiliation(s)
- Uri Weissbein
- Stem Cell Unit, Department of Genetics, Silberman Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
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Zainabadi K, Jain AV, Donovan FX, Elashoff D, Rao NP, Murty VV, Chandrasekharappa SC, Srivatsan ES. One in four individuals of African-American ancestry harbors a 5.5kb deletion at chromosome 11q13.1. Genomics 2014; 103:276-87. [PMID: 24412158 DOI: 10.1016/j.ygeno.2014.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 11/11/2013] [Accepted: 01/02/2014] [Indexed: 01/11/2023]
Abstract
Cloning and sequencing of 5.5 kb deletion at chromosome 11q13.1 from the HeLa cells, tumorigenic hybrids and two fibroblast cell lines have revealed homologous recombination between AluSx and AluY resulting in the deletion of intervening sequences. Long-range PCR of the 5.5 kb sequence in 494 normal lymphocyte samples showed heterozygous deletion in 28.3% of African-American ancestry samples but only in 4.8% of Caucasian samples (p<0.0001). This observation is strengthened by the copy number variation (CNV) data of the HapMap samples which showed that this deletion occurs in 27% of YRI (Yoruba--West African) population but none in non-African populations. The HapMap analysis further identified strong linkage disequilibrium between 5 single nucleotide polymorphisms and the 5.5 kb deletion in people of African ancestry. Computational analysis of 175 kb sequence surrounding the deletion site revealed enhanced flexibility, low thermodynamic stability, high repetitiveness, and stable stem-loop/hairpin secondary structures that are hallmarks of common fragile sites.
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Affiliation(s)
- Kayvan Zainabadi
- Division of General Surgery, Department of Surgery, VAGLAHS West Los Angeles, David Geffen School of Medicine at UCLA, Los Angeles, CA 90073, USA
| | - Anuja V Jain
- Division of General Surgery, Department of Surgery, VAGLAHS West Los Angeles, David Geffen School of Medicine at UCLA, Los Angeles, CA 90073, USA
| | - Frank X Donovan
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Elashoff
- Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90025, USA
| | - Nagesh P Rao
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90025, USA
| | - Vundavalli V Murty
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | - Settara C Chandrasekharappa
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eri S Srivatsan
- Division of General Surgery, Department of Surgery, VAGLAHS West Los Angeles, David Geffen School of Medicine at UCLA, Los Angeles, CA 90073, USA.
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45
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Boyer AS, Grgurevic S, Cazaux C, Hoffmann JS. The Human Specialized DNA Polymerases and Non-B DNA: Vital Relationships to Preserve Genome Integrity. J Mol Biol 2013; 425:4767-81. [DOI: 10.1016/j.jmb.2013.09.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/17/2013] [Accepted: 09/19/2013] [Indexed: 12/26/2022]
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46
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Abstract
Common fragile sites (CFSs) are chromosomal regions that are prone to form breaks or gaps during mitosis, in particular following replication stress. The mechanisms modulating CFS expression and promoting safe chromatid transmission to daughter cells are not clear. Now CFS expression is shown to reflect the activity of the MUS81-EME1 resolvase complex which cooperates with the dissolving action of the BLM helicase to prevent uncontrolled chromosome breakage and to promote genome integrity.
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Gross E, Meul C, Raab S, Propping C, Avril S, Aubele M, Gkazepis A, Schuster T, Grebenchtchikov N, Schmitt M, Kiechle M, Meijer J, Vijzelaar R, Meindl A, van Kuilenburg ABP. Somatic copy number changes in DPYD are associated with lower risk of recurrence in triple-negative breast cancers. Br J Cancer 2013; 109:2347-55. [PMID: 24104963 PMCID: PMC3817342 DOI: 10.1038/bjc.2013.621] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 09/06/2013] [Accepted: 09/15/2013] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Genomic rearrangements at the fragile site FRA1E may disrupt the dihydropyrimidine dehydrogenase gene (DPYD) which is involved in 5-fluorouracil (5-FU) catabolism. In triple-negative breast cancer (TNBC), a subtype of breast cancer frequently deficient in DNA repair, we have investigated the susceptibility to acquire copy number variations (CNVs) in DPYD and evaluated their impact on standard adjuvant treatment. METHODS DPYD CNVs were analysed in 106 TNBC tumour specimens using multiplex ligation-dependent probe amplification (MLPA) analysis. Dihydropyrimidine dehydrogenase (DPD) expression was determined by immunohistochemistry in 146 tumour tissues. RESULTS In TNBC, we detected 43 (41%) tumour specimens with genomic deletions and/or duplications within DPYD which were associated with higher histological grade (P=0.006) and with rearrangements in the DNA repair gene BRCA1 (P=0.007). Immunohistochemical analysis revealed low, moderate and high DPD expression in 64%, 29% and 7% of all TNBCs, and in 40%, 53% and 7% of TNBCs with DPYD CNVs, respectively. Irrespective of DPD protein levels, the presence of CNVs was significantly related to longer time to progression in patients who had received 5-FU- and/or anthracycline-based polychemotherapy (hazard ratio=0.26 (95% CI: 0.07-0.91), log-rank P=0.023; adjusted for tumour stage: P=0.037). CONCLUSION Genomic rearrangements in DPYD, rather than aberrant DPD protein levels, reflect a distinct tumour profile associated with prolonged time to progression upon first-line chemotherapy in TNBC.
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Affiliation(s)
- E Gross
- Department of Gynecology and Obstetrics, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
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Genome instability at common fragile sites: searching for the cause of their instability. BIOMED RESEARCH INTERNATIONAL 2013; 2013:730714. [PMID: 24083238 PMCID: PMC3780545 DOI: 10.1155/2013/730714] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 08/07/2013] [Indexed: 12/24/2022]
Abstract
Common fragile sites (CFS) are heritable nonrandomly distributed loci on human chromosomes that exhibit an increased frequency of chromosomal breakage under conditions of replication stress. They are considered the preferential targets for high genomic instability from the earliest stages of human cancer development, and increased chromosome instability at these loci has been observed following replication stress in a subset of human genetic diseases. Despite their biological and medical relevance, the molecular basis of CFS fragility in vivo has not been fully elucidated. At present, different models have been proposed to explain how instability at CFS arises and multiple factors seem to contribute to their instability. However, all these models involve DNA replication and suggest that replication fork stalling along CFS during DNA synthesis is a very frequent event. Consistent with this, the maintenance of CFS stability relies on the ATR-dependent checkpoint, together with a number of proteins promoting the recovery of stalled replication forks. In this review, we discuss mainly the possible causes that threaten the integrity of CFS in the light of new findings, paying particular attention to the role of the S-phase checkpoint.
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Landau DA, Carter SL, Getz G, Wu CJ. Clonal evolution in hematological malignancies and therapeutic implications. Leukemia 2013; 28:34-43. [PMID: 23979521 DOI: 10.1038/leu.2013.248] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 07/22/2013] [Accepted: 08/14/2013] [Indexed: 12/19/2022]
Abstract
The ability of cancer to evolve and adapt is a principal challenge to therapy in general and to the paradigm of targeted therapy in particular. This ability is fueled by the co-existence of multiple, genetically heterogeneous subpopulations within the cancer cell population. Increasing evidence has supported the idea that these subpopulations are selected in a Darwinian fashion, by which the genetic landscape of the tumor is continuously reshaped. Massively parallel sequencing has enabled a recent surge in our ability to study this process, adding to previous efforts using cytogenetic methods and targeted sequencing. Altogether, these studies reveal the complex evolutionary trajectories occurring across individual hematological malignancies. They also suggest that while clonal evolution may contribute to resistance to therapy, treatment may also hasten the evolutionary process. New insights into this process challenge us to understand the impact of treatment on clonal evolution and inspire the development of novel prognostic and therapeutic strategies.
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Affiliation(s)
- D A Landau
- 1] Cancer Vaccine Center, Dana-Farber Cancer Institute, Boston, MA, USA [2] Broad Institute, Cambridge, MA, USA [3] Department of Hematology, Yale Cancer Center, New Haven, CT, USA [4] Université Paris Diderot, Paris, France
| | | | - G Getz
- 1] Broad Institute, Cambridge, MA, USA [2] Massachusetts General Hospital Cancer Center and Department of Pathology, Boston, MA, USA
| | - C J Wu
- 1] Cancer Vaccine Center, Dana-Farber Cancer Institute, Boston, MA, USA [2] Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA [3] Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Schmitz S, Pinkawa M, Eble MJ, Kriehuber R. Persisting ring chromosomes detected by mFISH in lymphocytes of a cancer patient-a case report. Mutat Res 2013; 756:158-64. [PMID: 23792211 DOI: 10.1016/j.mrgentox.2013.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 06/11/2013] [Indexed: 10/26/2022]
Abstract
We report the case of an 84 years old prostate cancer patient with severe side effects after radiotherapy in 2006. He was cytogenetically analysed in 2009 and in 2012 in a comparative study for individual radiosensitivity of prostate cancer patients. No other patient had clonal aberrations, but this patient showed ring chromosomes in the range of 21-25% of lymphocytes. He received 5 cycles of 5-fluorouracil/folic acid for chemotherapy of sigmoid colon carcinoma in 2003, three years before radiotherapy of prostate cancer. Blood samples were irradiated ex vivo with Cs-137 γ-rays (0.7Gy/min) in the G0-phase of the cell cycle. 100 FISH painted metaphases were analysed for the control and the irradiated samples each. Multicolour in situ hybridisation techniques like mFISH and mBand as well as MYC locus, telomere and centromere painting probes were used to characterise ring metaphases. Metaphase search and autocapture was performed with a Zeiss Axioplan 2 imaging microscope followed by scoring and image analysis using Metafer 4/ISIS software (MetaSystems). In 2009 chromosome 8 rings were found in about 25% of lymphocytes. Rings were stable over time and increased to about 30% until 2012. The ring chromosome 8 always lacked telomere signals and a small amount of rings displayed up to four centromere signals. In aberrant metaphases 8pter and 8qter were either translocated or deleted. Further analyses revealed that the breakpoint at the p arm is localised at 8p21.2-22. The breakpoint at the q arm turned out to be distal from the MYC locus at 8q23-24. We hypothesise that the ring chromosome 8 has been developed during the 5 FU/folic acid treatments in 2003. The long term persistence might be due to clonal expansion of a damaged but viable hematopoietic stem cell giving rise to cycling progenitor cells that permit cell survival and proliferation.
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Affiliation(s)
- Sabine Schmitz
- Department of Safety and Radiation Protection, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany.
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