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De-Paula RB, Bacolla A, Syed A, Tainer JA. Enriched G4 forming repeats in the human genome are associated with robust well-coordinated transcription and reduced cancer transcriptome variation. J Biol Chem 2024:107822. [PMID: 39341500 DOI: 10.1016/j.jbc.2024.107822] [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: 05/24/2024] [Revised: 09/01/2024] [Accepted: 09/21/2024] [Indexed: 10/01/2024] Open
Abstract
Non-B DNA G-quadruplex (G4) structures with guanine (G) runs of 2-4 repeats can trigger opposing experimental transcriptional impacts. Here, we employed bioinformatic algorithms to comprehensively assess correlations of steady-state RNA transcript levels with all putative G4 sequence (pG4) locations genome-wide in three mammalian genomes and in normal and tumor human tissues. The human pG4-containing gene set displays higher expression levels than the set without pG4, supporting and extending some prior observations. pG4 enrichment at transcription start sites (TSS) in human, but not chimpanzee and mouse genomes, suggests possible positive selection pressure for pG4 at human TSS, potentially driving genome rewiring and gene expression divergence between human and chimpanzee. Comprehensive bioinformatic analyses revealed lower pG4-containing gene set variability in humans and among different pG4 genes in tumors. As G4 stabilizers are under therapeutic consideration for cancer and pathogens, such distinctions between human normal and tumor G4s along with other species merit attention. Furthermore, in germline and cancer sequences, the most mutagenic pG4 mapped to regions promoting alternative DNA structures. Overall findings establish high pG4 at TSS as a human genome attribute statistically associated with robust well-coordinated transcription and reduced cancer transcriptome variation with implications for biology, model organisms, and medicine.
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Affiliation(s)
- Ruth B De-Paula
- Graduate School of Biomedical Sciences, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Albino Bacolla
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Aleem Syed
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - John A Tainer
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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2
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Francis S, Rajith L. Nanomolar Fluorescent Detection of Guanine Using Tin Porphyrin. J Fluoresc 2024; 34:1049-1056. [PMID: 37450084 DOI: 10.1007/s10895-023-03336-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/30/2023] [Indexed: 07/18/2023]
Abstract
5,10,15,20-tetramethoxyphenylporphyrinatotin (IV) (SnTMPP) was synthesised. SnTMPP exhibited Soret band at 432 nm and emission peaks at 629 and 682 nm. The fluorescence intensity of SnTMPP was quenched in the presence of guanine linearly in the range 4 × 10-9 M to 7.2 × 10-8 M and the quenching response was found to be stable even in the presence of other nucleosides such as adenine, cytosine, uracil, thymine, alanine, aspartic acid and ascorbic acid. The detection limit was found to be 0.17 nM and the mechanism behind the decrease in the fluorescence intensity of SnTMPP in the presence of guanine is due to dynamic quenching, which was confirmed by cyclic voltammetric studies and life time studies. The CV studies illustrates the possibilty for an electron transfer between the guanine and the electron deficient metal core of SnTMPP.
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Affiliation(s)
- Shijo Francis
- Department of Applied Chemistry, Cochin University of Science and Technology, Kochi, Kerala, India, 682022
| | - Leena Rajith
- Department of Applied Chemistry, Cochin University of Science and Technology, Kochi, Kerala, India, 682022.
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3
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Xu Q, del Mundo IMA, Zewail-Foote M, Luke BT, Vasquez KM, Kowalski J. MoCoLo: a testing framework for motif co-localization. Brief Bioinform 2024; 25:bbae019. [PMID: 38521050 PMCID: PMC10960634 DOI: 10.1093/bib/bbae019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 03/25/2024] Open
Abstract
Sequence-level data offers insights into biological processes through the interaction of two or more genomic features from the same or different molecular data types. Within motifs, this interaction is often explored via the co-occurrence of feature genomic tracks using fixed-segments or analytical tests that respectively require window size determination and risk of false positives from over-simplified models. Moreover, methods for robustly examining the co-localization of genomic features, and thereby understanding their spatial interaction, have been elusive. We present a new analytical method for examining feature interaction by introducing the notion of reciprocal co-occurrence, define statistics to estimate it and hypotheses to test for it. Our approach leverages conditional motif co-occurrence events between features to infer their co-localization. Using reverse conditional probabilities and introducing a novel simulation approach that retains motif properties (e.g. length, guanine-content), our method further accounts for potential confounders in testing. As a proof-of-concept, motif co-localization (MoCoLo) confirmed the co-occurrence of histone markers in a breast cancer cell line. As a novel analysis, MoCoLo identified significant co-localization of oxidative DNA damage within non-B DNA-forming regions that significantly differed between non-B DNA structures. Altogether, these findings demonstrate the potential utility of MoCoLo for testing spatial interactions between genomic features via their co-localization.
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Affiliation(s)
- Qi Xu
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Imee M A del Mundo
- Dell Pediatric Research Institute, Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas, 78723, USA
| | - Maha Zewail-Foote
- Department of Chemistry and Biochemistry, Southwestern University, Georgetown, TX, 78626, USA
| | - Brian T Luke
- Bioinformatics and Computational Science, Frederick National Laboratory for Cancer Research, Frederick, Maryland, 21701, USA
| | - Karen M Vasquez
- Dell Pediatric Research Institute, Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas, 78723, USA
| | - Jeanne Kowalski
- Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
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4
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Vandenberg BN, Laughery MF, Cordero C, Plummer D, Mitchell D, Kreyenhagen J, Albaqshi F, Brown AJ, Mieczkowski PA, Wyrick JJ, Roberts SA. Contributions of replicative and translesion DNA polymerases to mutagenic bypass of canonical and atypical UV photoproducts. Nat Commun 2023; 14:2576. [PMID: 37142570 PMCID: PMC10160025 DOI: 10.1038/s41467-023-38255-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 04/21/2023] [Indexed: 05/06/2023] Open
Abstract
UV exposure induces a mutation signature of C > T substitutions at dipyrimidines in skin cancers. We recently identified additional UV-induced AC > TT and A > T substitutions that could respectively cause BRAF V600K and V600E oncogenic mutations. The mutagenic bypass mechanism past these atypical lesions, however, is unknown. Here, we whole genome sequenced UV-irradiated yeast and used reversion reporters to delineate the roles of replicative and translesion DNA polymerases in mutagenic bypass of UV-lesions. Our data indicates that yeast DNA polymerase eta (pol η) has varied impact on UV-induced mutations: protecting against C > T substitutions, promoting T > C and AC > TT substitutions, and not impacting A > T substitutions. Surprisingly, deletion rad30Δ increased novel UV-induced C > A substitutions at CA dinucleotides. In contrast, DNA polymerases zeta (pol ζ) and epsilon (pol ε) participated in AC > TT and A > T mutations. These results uncover lesion-specific accurate and mutagenic bypass of UV lesions, which likely contribute to key driver mutations in melanoma.
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Affiliation(s)
- Brittany N Vandenberg
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA
| | - Marian F Laughery
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA
| | - Cameron Cordero
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA
| | - Dalton Plummer
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA
| | - Debra Mitchell
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA
| | - Jordan Kreyenhagen
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA
| | - Fatimah Albaqshi
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA
| | - Alexander J Brown
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA
| | - Piotr A Mieczkowski
- Department of Genetics, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - John J Wyrick
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA.
| | - Steven A Roberts
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA, 99164, USA.
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5
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Rooman M, Pucci F. Estimating the Vertical Ionization Potential of Single-Stranded DNA Molecules. J Chem Inf Model 2023; 63:1766-1775. [PMID: 36877828 DOI: 10.1021/acs.jcim.2c01525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
The electronic properties of DNA molecules, defined by the sequence-dependent ionization potentials of nucleobases, enable long-range charge transport along the DNA stacks. This has been linked to a range of key physiological processes in the cells and to the triggering of nucleobase substitutions, some of which may cause diseases. To gain molecular-level understanding of the sequence dependence of these phenomena, we estimated the vertical ionization potential (vIP) of all possible nucleobase stacks in B-conformation, containing one to four Gua, Ade, Thy, Cyt, or methylated Cyt. To do this, we used quantum chemistry calculations and more precisely the second-order Møller-Plesset perturbation theory (MP2) and three double-hybrid density functional theory methods, combined with several basis sets for describing atomic orbitals. The calculated vIP of single nucleobases were compared to experimental data and those of nucleobase pairs, triplets, and quadruplets, to observed mutability frequencies in the human genome, reported to be correlated with vIP values. This comparison selected MP2 with the 6-31G* basis set as the best of the tested calculation levels. These results were exploited to set up a recursive model, called vIPer, which estimates the vIP of all possible single-stranded DNA sequences of any length based on the calculated vIPs of overlapping quadruplets. vIPer's vIP values correlate well with oxidation potentials measured by cyclic voltammetry and activities obtained through photoinduced DNA cleavage experiments, further validating our approach. vIPer is freely available on the github.com/3BioCompBio/vIPer repository.
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Affiliation(s)
- Marianne Rooman
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, 1050 Brussels, Belgium.,Interuniversity Institute of Bioinformatics in Brussels, 1050 Brussels, Belgium
| | - Fabrizio Pucci
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, 1050 Brussels, Belgium.,Interuniversity Institute of Bioinformatics in Brussels, 1050 Brussels, Belgium
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6
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Tiek DM, Erdogdu B, Razaghi R, Jin L, Sadowski N, Alamillo-Ferrer C, Hogg JR, Haddad BR, Drewry DH, Wells CI, Pickett JE, Song X, Goenka A, Hu B, Goldlust SA, Zuercher WJ, Pertea M, Timp W, Cheng SY, Riggins RB. Temozolomide-induced guanine mutations create exploitable vulnerabilities of guanine-rich DNA and RNA regions in drug-resistant gliomas. SCIENCE ADVANCES 2022; 8:eabn3471. [PMID: 35731869 PMCID: PMC9216507 DOI: 10.1126/sciadv.abn3471] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 05/04/2022] [Indexed: 05/28/2023]
Abstract
Temozolomide (TMZ) is a chemotherapeutic agent that has been the first-line standard of care for the aggressive brain cancer glioblastoma (GBM) since 2005. Although initially beneficial, TMZ resistance is universal and second-line interventions are an unmet clinical need. Here, we took advantage of the known mechanism of action of TMZ to target guanines (G) and investigated G-rich G-quadruplex (G4) and splice site changes that occur upon TMZ resistance. We report that TMZ-resistant GBM has guanine mutations that disrupt the G-rich DNA G4s and splice sites that lead to deregulated alternative splicing. These alterations create vulnerabilities, which are selectively targeted by either the G4-stabilizing drug TMPyP4 or a novel splicing kinase inhibitor of cdc2-like kinase. Last, we show that the G4 and RNA binding protein EWSR1 aggregates in the cytoplasm in TMZ-resistant GBM cells and patient samples. Together, our findings provide insight into targetable vulnerabilities of TMZ-resistant GBM and present cytoplasmic EWSR1 as a putative biomarker.
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Affiliation(s)
- Deanna M. Tiek
- The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute, and Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Beril Erdogdu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Roham Razaghi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Lu Jin
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Norah Sadowski
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Carla Alamillo-Ferrer
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - J. Robert Hogg
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bassem R. Haddad
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
| | - David H. Drewry
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- UNC Lineberger Comprehensive Cancer Center, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Carrow I. Wells
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Julie E. Pickett
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Xiao Song
- The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute, and Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Anshika Goenka
- The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute, and Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Bo Hu
- The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute, and Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Samuel A. Goldlust
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
- John Theurer Cancer Center, Hackensack University Medical Center, Hackensack, NJ 07601, USA
| | - William J. Zuercher
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Mihaela Pertea
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Winston Timp
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Shi-Yuan Cheng
- The Ken and Ruth Davee Department of Neurology, Lou and Jean Malnati Brain Tumor Institute, and Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Rebecca B. Riggins
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA
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7
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Díaz-Muñoz M, Hernández-Muñoz R, Butanda-Ochoa A. Structure-activity features of purines and their receptors: implications in cell physiopathology. MOLECULAR BIOMEDICINE 2022; 3:5. [PMID: 35079944 PMCID: PMC8789959 DOI: 10.1186/s43556-022-00068-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 01/19/2022] [Indexed: 11/21/2022] Open
Abstract
The purine molecular structure consists of fused pyrimidine and imidazole rings. Purines are main pieces that conform the structure of nucleic acids which rule the inheritance processes. Purines also work as metabolic intermediates in different cell functions and as messengers in the signaling pathways throughout cellular communication. Purines, mainly ATP and adenosine (ADO), perform their functional and pharmacological properties because of their structural/chemical characteristics that make them either targets of mutagenesis, mother frameworks for designing molecules with controlled effects (e.g. anti-cancer), or chemical donors (e.g., of methyl groups, which represent a potential chemoprotective action against cancer). Purines functions also come from their effect on specific receptors, channel-linked and G-protein coupled for ATP, and exclusively G-coupled receptors for ADO (also known as ADORAs), which are involved in cell signaling pathways, there, purines work as chemical messengers with autocrine, paracrine, and endocrine actions that regulate cell metabolism and immune response in tumor progression which depends on the receptor types involved in these signals. Purines also have antioxidant and anti-inflammatory properties and participate in the cell energy homeostasis. Therefore, purine physiology is important for a variety of functions relevant to cellular health; thus, when these molecules present a homeostatic imbalance, the stability and survival of the cellular systems become compromised.
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Affiliation(s)
- Mauricio Díaz-Muñoz
- Departamento de Neurobiología Celular Y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, UNAM, Boulevard Juriquilla 3001, C.P. 76230, Juriquilla, Querétaro, México
| | - Rolando Hernández-Muñoz
- Departamento de Biología Celular Y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, UNAM, Ciudad Universitaria/Circuito Exterior, C.P. 04510, Ciudad de México, México
| | - Armando Butanda-Ochoa
- Departamento de Biología Celular Y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, UNAM, Ciudad Universitaria/Circuito Exterior, C.P. 04510, Ciudad de México, México.
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8
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Impact of G-Quadruplexes and Chronic Inflammation on Genome Instability: Additive Effects during Carcinogenesis. Genes (Basel) 2021; 12:genes12111779. [PMID: 34828385 PMCID: PMC8619830 DOI: 10.3390/genes12111779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 02/07/2023] Open
Abstract
Genome instability is an enabling characteristic of cancer, essential for cancer cell evolution. Hotspots of genome instability, from small-scale point mutations to large-scale structural variants, are associated with sequences that potentially form non-B DNA structures. G-quadruplex (G4) forming motifs are enriched at structural variant endpoints in cancer genomes. Chronic inflammation is a physiological state underlying cancer development, and oxidative DNA damage is commonly invoked to explain how inflammation promotes genome instability. We summarize where G4s and oxidative stress overlap, with a focus on DNA replication. Guanine has low ionization potential, making G4s vulnerable to oxidative damage. Impacts to G4 structure are dependent upon lesion type, location, and G4 conformation. Occasionally, G4s pose a challenge to replicative DNA polymerases, requiring specialized DNA polymerases to maintain genome stability. Therefore, chronic inflammation creates a dual challenge for DNA polymerases to maintain genome stability: faithful G4 synthesis and bypassing unrepaired oxidative lesions. Inflammation is also accompanied by global transcriptome changes that may impact mutagenesis. Several studies suggest a regulatory role for G4s within cancer- and inflammatory-related gene promoters. We discuss the extent to which inflammation could influence gene regulation by G4s, thereby impacting genome instability, and highlight key areas for new investigation.
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9
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El-Sharkawy YH, Elbasuney S, Radwan SM, Askar MA, El-Sayyad GS. Total RNA nonlinear polarization: towards facile early diagnosis of breast cancer. RSC Adv 2021; 11:33319-33325. [PMID: 35497529 PMCID: PMC9042301 DOI: 10.1039/d1ra05599b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/23/2021] [Indexed: 12/16/2022] Open
Abstract
Different cancers are caused by accumulation of numerous genetic and epigenetic changes. Recently, nonlinear polarization has been considered as a marvelous tool for several medical applications. The capability of nonlinear polarization, to monitor any changes in RNA's spectral signature due to breast cancer (BC) was evaluated. Blood samples, from healthy controls and BC patients, were collected for whole blood preparation for genomic total RNA purification. Total RNA samples were stimulated with a light-emitting diode (LED) source of 565 nm; the resonance frequency of investigated RNA samples was captured and processed via hyperspectral imaging. Resonance frequency signatures were processed using fast Fourier transform in an attempt to differentiate between RNA (control) and RNA (BC) via frequency response. RNA (BC) demonstrated a characteristic signal at 0.02 GHz, as well as a phase shift at 0.031, and 0.070 GHZ from RNA (control). These features could offer early BC diagnosis. This is the first time to describe an optical methodology based on nonlinear polarization as a facile principle to distinguish and identify RNA alterations in BC by their characteristic fingerprint spectral signature. Nonlinear polarization has been considered as a marvelous tool for several medical applications, and the capability to monitor any changes in RNA's spectral signature due to breast cancer was evaluated by hyperspectral camera.![]()
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Affiliation(s)
- Yasser H El-Sharkawy
- Head of Biomedical Engineering Department, Military Technical College Cairo Egypt
| | - Sherif Elbasuney
- Head of Nanotechnology Research Center, Military Technical College Cairo Egypt
| | - Sara M Radwan
- Biochemistry Department, Faculty of Pharmacy, Ain Shams University Cairo Egypt
| | - Mostafa A Askar
- Radiation Biology Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA) Cairo Egypt
| | - Gharieb S El-Sayyad
- Drug Radiation Research Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA) Cairo Egypt
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10
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Guiblet WM, Cremona MA, Harris RS, Chen D, Eckert KA, Chiaromonte F, Huang YF, Makova KD. Non-B DNA: a major contributor to small- and large-scale variation in nucleotide substitution frequencies across the genome. Nucleic Acids Res 2021; 49:1497-1516. [PMID: 33450015 PMCID: PMC7897504 DOI: 10.1093/nar/gkaa1269] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 12/14/2020] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
Approximately 13% of the human genome can fold into non-canonical (non-B) DNA structures (e.g. G-quadruplexes, Z-DNA, etc.), which have been implicated in vital cellular processes. Non-B DNA also hinders replication, increasing errors and facilitating mutagenesis, yet its contribution to genome-wide variation in mutation rates remains unexplored. Here, we conducted a comprehensive analysis of nucleotide substitution frequencies at non-B DNA loci within noncoding, non-repetitive genome regions, their ±2 kb flanking regions, and 1-Megabase windows, using human-orangutan divergence and human single-nucleotide polymorphisms. Functional data analysis at single-base resolution demonstrated that substitution frequencies are usually elevated at non-B DNA, with patterns specific to each non-B DNA type. Mirror, direct and inverted repeats have higher substitution frequencies in spacers than in repeat arms, whereas G-quadruplexes, particularly stable ones, have higher substitution frequencies in loops than in stems. Several non-B DNA types also affect substitution frequencies in their flanking regions. Finally, non-B DNA explains more variation than any other predictor in multiple regression models for diversity or divergence at 1-Megabase scale. Thus, non-B DNA substantially contributes to variation in substitution frequencies at small and large scales. Our results highlight the role of non-B DNA in germline mutagenesis with implications to evolution and genetic diseases.
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Affiliation(s)
- Wilfried M Guiblet
- Bioinformatics and Genomics Graduate Program, Penn State University, UniversityPark, PA 16802, USA
| | - Marzia A Cremona
- Department of Statistics, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Operations and Decision Systems, Université Laval, Canada
- CHU de Québec – Université Laval Research Center, Canada
| | - Robert S Harris
- Department of Biology, Penn State University, University Park, PA 16802, USA
| | - Di Chen
- Intercollege Graduate Degree Program in Genetics, Huck Institutes of the Life Sciences, Penn State University, UniversityPark, PA 16802, USA
| | - Kristin A Eckert
- Department of Pathology, Penn State University, College of Medicine, Hershey, PA 17033, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
| | - Francesca Chiaromonte
- Department of Statistics, The Pennsylvania State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
- EMbeDS, Sant’Anna School of Advanced Studies, 56127 Pisa, Italy
| | - Yi-Fei Huang
- Department of Biology, Penn State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
| | - Kateryna D Makova
- Department of Biology, Penn State University, University Park, PA 16802, USA
- Center for Medical Genomics, Penn State University, University Park and Hershey, PA, USA
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11
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Gadgil RY, Romer EJ, Goodman CC, Rider SD, Damewood FJ, Barthelemy JR, Shin-Ya K, Hanenberg H, Leffak M. Replication stress at microsatellites causes DNA double-strand breaks and break-induced replication. J Biol Chem 2020; 295:15378-15397. [PMID: 32873711 DOI: 10.1074/jbc.ra120.013495] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/23/2020] [Indexed: 12/12/2022] Open
Abstract
Short tandemly repeated DNA sequences, termed microsatellites, are abundant in the human genome. These microsatellites exhibit length instability and susceptibility to DNA double-strand breaks (DSBs) due to their tendency to form stable non-B DNA structures. Replication-dependent microsatellite DSBs are linked to genome instability signatures in human developmental diseases and cancers. To probe the causes and consequences of microsatellite DSBs, we designed a dual-fluorescence reporter system to detect DSBs at expanded (CTG/CAG) n and polypurine/polypyrimidine (Pu/Py) mirror repeat structures alongside the c-myc replication origin integrated at a single ectopic chromosomal site. Restriction cleavage near the (CTG/CAG)100 microsatellite leads to homology-directed single-strand annealing between flanking AluY elements and reporter gene deletion that can be detected by flow cytometry. However, in the absence of restriction cleavage, endogenous and exogenous replication stressors induce DSBs at the (CTG/CAG)100 and Pu/Py microsatellites. DSBs map to a narrow region at the downstream edge of the (CTG)100 lagging-strand template. (CTG/CAG) n chromosome fragility is repeat length-dependent, whereas instability at the (Pu/Py) microsatellites depends on replication polarity. Strikingly, restriction-generated DSBs and replication-dependent DSBs are not repaired by the same mechanism. Knockdown of DNA damage response proteins increases (Rad18, polymerase (Pol) η, Pol κ) or decreases (Mus81) the sensitivity of the (CTG/CAG)100 microsatellites to replication stress. Replication stress and DSBs at the ectopic (CTG/CAG)100 microsatellite lead to break-induced replication and high-frequency mutagenesis at a flanking thymidine kinase gene. Our results show that non-B structure-prone microsatellites are susceptible to replication-dependent DSBs that cause genome instability.
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Affiliation(s)
- Rujuta Yashodhan Gadgil
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Eric J Romer
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Caitlin C Goodman
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - S Dean Rider
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - French J Damewood
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Joanna R Barthelemy
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA
| | - Kazuo Shin-Ya
- Biomedical Information Research Center, National Institute of Advanced Industrial Science and Technology, Tokyo, Japan
| | - Helmut Hanenberg
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich Heine University, Düsseldorf, Germany; Department of Pediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Michael Leffak
- Department of Biochemistry and Molecular Biology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio, USA.
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12
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Bacolla A, Ye Z, Ahmed Z, Tainer JA. Cancer mutational burden is shaped by G4 DNA, replication stress and mitochondrial dysfunction. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 147:47-61. [PMID: 30880007 PMCID: PMC6745008 DOI: 10.1016/j.pbiomolbio.2019.03.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 03/08/2019] [Accepted: 03/12/2019] [Indexed: 02/01/2023]
Abstract
A hallmark of cancer is genomic instability, which can enable cancer cells to evade therapeutic strategies. Here we employed a computational approach to uncover mechanisms underlying cancer mutational burden by focusing upon relationships between 1) translocation breakpoints and the thousands of G4 DNA-forming sequences within retrotransposons impacting transcription and exemplifying probable non-B DNA structures and 2) transcriptome profiling and cancer mutations. We determined the location and number of G4 DNA-forming sequences in the Genome Reference Consortium Human Build 38 and found a total of 358,605 covering ∼13.4 million bases. By analyzing >97,000 unique translocation breakpoints from the Catalogue Of Somatic Mutations In Cancer (COSMIC), we found that breakpoints are overrepresented at G4 DNA-forming sequences within hominid-specific SVA retrotransposons, and generally occur in tumors with mutations in tumor suppressor genes, such as TP53. Furthermore, correlation analyses between mRNA levels and exome mutational loads from The Cancer Genome Atlas (TCGA) encompassing >450,000 gene-mutation regressions revealed strong positive and negative associations, which depended upon tissue of origin. The strongest positive correlations originated from genes not listed as cancer genes in COSMIC; yet, these show strong predictive power for survival in most tumor types by Kaplan-Meier estimation. Thus, correlation analyses of DNA structure and gene expression with mutation loads complement and extend more traditional approaches to elucidate processes shaping genomic instability in cancer. The combined results point to G4 DNA, activation of cell cycle/DNA repair pathways, and mitochondrial dysfunction as three major factors driving the accumulation of somatic mutations in cancer cells.
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Affiliation(s)
- Albino Bacolla
- Departments of Cancer Biology and of Molecular and Cellular Oncology, The University of Texas M.D. Anderson Cancer Center, 6767 Bertner Avenue, Houston, TX, 77030, USA.
| | - Zu Ye
- Departments of Cancer Biology and of Molecular and Cellular Oncology, The University of Texas M.D. Anderson Cancer Center, 6767 Bertner Avenue, Houston, TX, 77030, USA.
| | - Zamal Ahmed
- Departments of Cancer Biology and of Molecular and Cellular Oncology, The University of Texas M.D. Anderson Cancer Center, 6767 Bertner Avenue, Houston, TX, 77030, USA.
| | - John A Tainer
- Departments of Cancer Biology and of Molecular and Cellular Oncology, The University of Texas M.D. Anderson Cancer Center, 6767 Bertner Avenue, Houston, TX, 77030, USA.
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13
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Pucci F, Rooman M. Relation between DNA ionization potentials, single base substitutions and pathogenic variants. BMC Genomics 2019; 20:551. [PMID: 31307386 PMCID: PMC6631442 DOI: 10.1186/s12864-019-5867-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background It is nowadays clear that single base substitutions that occur in the human genome, of which some lead to pathogenic conditions, are non-random and influenced by their flanking nucleobase sequences. However, despite recent progress, the understanding of these "non-local" effects is still far from being achieved. Results To advance this problem, we analyzed the relationship between the base mutability in specific gene regions and the electron hole transport along the DNA base stacks, as it is one of the mechanisms that have been suggested to contribute to these effects. More precisely, we studied the connection between the normalized frequency of single base substitutions and the vertical ionization potential of the base and its flanking sequence, estimated using MP2/6-31G* ab initio quantum chemistry calculations. We found a statistically significant overall anticorrelation between these two quantities: the lower the vIP value, the more probable the substitution. Moreover, the slope of the regression lines varies. It is larger for introns than for exons and untranslated regions, and for synonymous than for missense substitutions. Interestingly, the correlation appears to be more pronounced when considering the flanking sequence of the substituted base in the 3’ rather than in the 5’ direction, which corresponds to the preferred direction of charge migration. A weaker but still statistically significant correlation is found between the ionization potentials and the pathogenicity of the base substitutions. Moreover, pathogenicity is also preferentially associated with larger changes in ionization potentials upon base substitution. Conclusions With this analysis we gained new insights into the complex biophysical mechanisms that are at the basis of mutagenesis and pathogenicity, and supported the role of electron-hole transport in these matters. Electronic supplementary material The online version of this article (10.1186/s12864-019-5867-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fabrizio Pucci
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Roosevelt Ave. 50, Bruxelles, 1050, Belgium.,John von Neumann Institute for Computing, Jülich Supercomputer Centre, Forschungszentrum Jülich, Jülich, 52428, Germany
| | - Marianne Rooman
- Computational Biology and Bioinformatics, Université Libre de Bruxelles, Roosevelt Ave. 50, Bruxelles, 1050, Belgium.
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14
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Sakurai S, Esumi M, Tanaka M. Drastic promotion of guanine oxidation via electron transfer in Ψ-type DNA. Chem Commun (Camb) 2019; 55:7695-7698. [DOI: 10.1039/c9cc02255d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Drastic promotion of guanine oxidation was induced by not only intraduplex ET but also interduplex ET in Ψ-type DNA in a crowded environment using PEG.
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Affiliation(s)
- Shunsuke Sakurai
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
| | - Mayu Esumi
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
| | - Makiko Tanaka
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
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15
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Suárez-Villagrán MY, Azevedo RBR, Miller JH. Influence of Electron-Holes on DNA Sequence-Specific Mutation Rates. Genome Biol Evol 2018; 10:1039-1047. [PMID: 29617801 PMCID: PMC5887664 DOI: 10.1093/gbe/evy060] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/20/2018] [Indexed: 12/22/2022] Open
Abstract
Biases in mutation rate can influence molecular evolution, yielding rates of evolution that vary widely in different parts of the genome and even among neighboring nucleotides. Here, we explore one possible mechanism of influence on sequence-specific mutation rates, the electron–hole, which can localize and potentially trigger a replication mismatch. A hole is a mobile site of positive charge created during one-electron oxidation by, for example, radiation, contact with a mutagenic agent, or oxidative stress. Its quantum wavelike properties cause it to localize at various sites with probabilities that vary widely, by orders of magnitude, and depend strongly on the local sequence. We find significant correlations between hole probabilities and mutation rates within base triplets, observed in published mutation accumulation experiments on four species of bacteria. We have also computed hole probability spectra for hypervariable segment I of the human mtDNA control region, which contains several mutational hotspots, and for heptanucleotides in noncoding regions of the human genome, whose polymorphism levels have recently been reported. We observe significant correlations between hole probabilities, and context-specific mutation and substitution rates. The correlation with hole probability cannot be explained entirely by CpG methylation in the heptanucleotide data. Peaks in hole probability tend to coincide with mutational hotspots, even in mtDNA where CpG methylation is rare. Our results suggest that hole-enhanced mutational mechanisms, such as oxidation-stabilized tautomerization and base deamination, contribute to molecular evolution.
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Affiliation(s)
- Martha Y Suárez-Villagrán
- Department of Physics, University of Houston, Houston.,Texas Center for Superconductivity, University of Houston, Houston
| | | | - John H Miller
- Department of Physics, University of Houston, Houston.,Texas Center for Superconductivity, University of Houston, Houston
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16
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Pantsar T, Rissanen S, Dauch D, Laitinen T, Vattulainen I, Poso A. Assessment of mutation probabilities of KRAS G12 missense mutants and their long-timescale dynamics by atomistic molecular simulations and Markov state modeling. PLoS Comput Biol 2018; 14:e1006458. [PMID: 30199525 PMCID: PMC6147662 DOI: 10.1371/journal.pcbi.1006458] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 09/20/2018] [Accepted: 08/22/2018] [Indexed: 12/29/2022] Open
Abstract
A mutated KRAS protein is frequently observed in human cancers. Traditionally, the oncogenic properties of KRAS missense mutants at position 12 (G12X) have been considered as equal. Here, by assessing the probabilities of occurrence of all KRAS G12X mutations and KRAS dynamics we show that this assumption does not hold true. Instead, our findings revealed an outstanding mutational bias. We conducted a thorough mutational analysis of KRAS G12X mutations and assessed to what extent the observed mutation frequencies follow a random distribution. Unique tissue-specific frequencies are displayed with specific mutations, especially with G12R, which cannot be explained by random probabilities. To clarify the underlying causes for the nonrandom probabilities, we conducted extensive atomistic molecular dynamics simulations (170 μs) to study the differences of G12X mutations on a molecular level. The simulations revealed an allosteric hydrophobic signaling network in KRAS, and that protein dynamics is altered among the G12X mutants and as such differs from the wild-type and is mutation-specific. The shift in long-timescale conformational dynamics was confirmed with Markov state modeling. A G12X mutation was found to modify KRAS dynamics in an allosteric way, which is especially manifested in the switch regions that are responsible for the effector protein binding. The findings provide a basis to understand better the oncogenic properties of KRAS G12X mutants and the consequences of the observed nonrandom frequencies of specific G12X mutations. The oncogene KRAS is frequently mutated in various cancers. When the amino acid glycine 12 is mutated, KRAS protein acquires oncogenic properties that result in tumor cell-growth and cancer progression. These mutations prevail especially in the pancreatic ductal adenocarcinoma, which is a cancer with an exceptionally dismal prognosis. To date, there is a limited understanding of the different mutations at the position 12, also regarding whether the different mutations would have different consequences. These discrepancies could have major implications for the future drug therapies targeting KRAS mutant harboring tumors. In this study, we made a critical assessment of the observed frequency of KRAS G12X mutations and the underlying causes for these frequencies. We also assessed KRAS G12X mutant discrepancies on an atomistic level by utilizing state-of-the-art molecular dynamics simulations. We found that the dynamics of the mutants does not only differ from the wild-type protein, but there is also a profound difference among the different mutants. These results emphasize that the different KRAS G12X mutations are not equal, and thereby they suggest that the future research related to mutant KRAS biology should account for these observations.
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Affiliation(s)
- Tatu Pantsar
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
- * E-mail: (TP); (AP)
| | - Sami Rissanen
- Laboratory of Physics, Tampere University of Technology, Tampere, Finland
| | - Daniel Dauch
- Department of Internal Medicine VIII, University Hospital Tuebingen, Tuebingen, Germany
- Department of Physiology I, Institute of Physiology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Tuomo Laitinen
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Ilpo Vattulainen
- Laboratory of Physics, Tampere University of Technology, Tampere, Finland
- Department of Physics, University of Helsinki, Helsinki, Finland
- MEMPHYS-Center for Biomembrane Physics, Helsinki, Finland
| | - Antti Poso
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
- Department of Internal Medicine VIII, University Hospital Tuebingen, Tuebingen, Germany
- * E-mail: (TP); (AP)
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17
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Kim HY, Lee KM, Kim SH, Kwon YJ, Chun YJ, Choi HK. Comparative metabolic and lipidomic profiling of human breast cancer cells with different metastatic potentials. Oncotarget 2018; 7:67111-67128. [PMID: 27564096 PMCID: PMC5341861 DOI: 10.18632/oncotarget.11560] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/11/2016] [Indexed: 12/30/2022] Open
Abstract
This study conducted comprehensive and comparative metabolic and lipidomic profiling of a human epithelial breast cell line (MCF-10A), a slightly metastatic (MCF-7), and a highly metastatic (MDA-MB-231) breast cancer cell line using gas chromatography mass spectrometry (GC-MS) and direct infusion mass spectrometry (DI-MS). Among 39 metabolites identified by GC-MS analysis, xanthine, glucose-6-phosphate, mannose-6-phosphate, guanine, and adenine were selected as prognostic markers of breast cancer metastasis. Major metabolic pathways involved in differentiation of the cell lines were alanine, aspartate, and glutamate metabolism, purine metabolism and glycine, serine, and threonine metabolism. Among 44 intact lipid species identified by DI-MS analysis, the levels of most phospholipids were higher in both metastatic groups than in normal cells. Specifically, the levels of phosphatidylserine (PS) 18:0/20:4, phosphatidylinositol (PI) 18:0/20:4, and phosphatidylcholine (PC) 18:0/20:4 were markedly higher while those of phosphatidylethanolamine (PE) 18:1/18:1 and PI 18:0/18:1 were lower in MDA-MB-231 cells than in MCF-7 cells. A partial-least-squares regression model was developed and validated for predicting the metastatic potential of breast cancer cells. The information obtained in this study will be useful when developing diagnostic tools and for identifying potential therapeutic targets for metastatic breast cancer.
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Affiliation(s)
- Hye-Youn Kim
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Kyung-Min Lee
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - So-Hyun Kim
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Yeo-Jung Kwon
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Young-Jin Chun
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
| | - Hyung-Kyoon Choi
- College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
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18
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Tanaka M, Matsumoto T, Iida H. Attenuation of guanine oxidation via DNA-mediated electron transfer in a crowded environment using small cosolutes. Org Biomol Chem 2018; 16:6695-6702. [DOI: 10.1039/c8ob02003e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Guanine oxidation induced by photoirradiation on a pyrene-modified oligonucleotide was investigated under molecular crowding using small cosolutes such as glycerol.
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Affiliation(s)
- Makiko Tanaka
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
| | - Takayuki Matsumoto
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
| | - Hiroki Iida
- Department of Engineering Science
- Graduate School of Informatics and Engineering
- The University of Electro-Communications
- Chofu
- Japan
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19
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Eichler DR, Hamann HA, Harte KA, Papadantonakis GA. Hydration effects on the photoionization energy of 2′-deoxyguanosine 5′-phosphate and activation barriers for guanine methylation by carcinogenic methane diazonium ions. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.05.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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20
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Stenson PD, Mort M, Ball EV, Evans K, Hayden M, Heywood S, Hussain M, Phillips AD, Cooper DN. The Human Gene Mutation Database: towards a comprehensive repository of inherited mutation data for medical research, genetic diagnosis and next-generation sequencing studies. Hum Genet 2017. [PMID: 28349240 DOI: 10.1007/s00439‐017‐1779‐6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The Human Gene Mutation Database (HGMD®) constitutes a comprehensive collection of published germline mutations in nuclear genes that underlie, or are closely associated with human inherited disease. At the time of writing (March 2017), the database contained in excess of 203,000 different gene lesions identified in over 8000 genes manually curated from over 2600 journals. With new mutation entries currently accumulating at a rate exceeding 17,000 per annum, HGMD represents de facto the central unified gene/disease-oriented repository of heritable mutations causing human genetic disease used worldwide by researchers, clinicians, diagnostic laboratories and genetic counsellors, and is an essential tool for the annotation of next-generation sequencing data. The public version of HGMD ( http://www.hgmd.org ) is freely available to registered users from academic institutions and non-profit organisations whilst the subscription version (HGMD Professional) is available to academic, clinical and commercial users under license via QIAGEN Inc.
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Affiliation(s)
- Peter D Stenson
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK.
| | - Matthew Mort
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Edward V Ball
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Katy Evans
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Matthew Hayden
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Sally Heywood
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Michelle Hussain
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Andrew D Phillips
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - David N Cooper
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK.
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21
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Stenson PD, Mort M, Ball EV, Evans K, Hayden M, Heywood S, Hussain M, Phillips AD, Cooper DN. The Human Gene Mutation Database: towards a comprehensive repository of inherited mutation data for medical research, genetic diagnosis and next-generation sequencing studies. Hum Genet 2017; 136:665-677. [PMID: 28349240 PMCID: PMC5429360 DOI: 10.1007/s00439-017-1779-6] [Citation(s) in RCA: 912] [Impact Index Per Article: 130.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 03/14/2017] [Indexed: 02/06/2023]
Abstract
The Human Gene Mutation Database (HGMD®) constitutes a comprehensive collection of published germline mutations in nuclear genes that underlie, or are closely associated with human inherited disease. At the time of writing (March 2017), the database contained in excess of 203,000 different gene lesions identified in over 8000 genes manually curated from over 2600 journals. With new mutation entries currently accumulating at a rate exceeding 17,000 per annum, HGMD represents de facto the central unified gene/disease-oriented repository of heritable mutations causing human genetic disease used worldwide by researchers, clinicians, diagnostic laboratories and genetic counsellors, and is an essential tool for the annotation of next-generation sequencing data. The public version of HGMD (http://www.hgmd.org) is freely available to registered users from academic institutions and non-profit organisations whilst the subscription version (HGMD Professional) is available to academic, clinical and commercial users under license via QIAGEN Inc.
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Affiliation(s)
- Peter D Stenson
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK.
| | - Matthew Mort
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Edward V Ball
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Katy Evans
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Matthew Hayden
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Sally Heywood
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Michelle Hussain
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - Andrew D Phillips
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
| | - David N Cooper
- School of Medicine, Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK.
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22
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Rotunno M, McMaster ML, Boland J, Bass S, Zhang X, Burdett L, Hicks B, Ravichandran S, Luke BT, Yeager M, Fontaine L, Hyland PL, Goldstein AM, Chanock SJ, Caporaso NE, Tucker MA, Goldin LR. Whole exome sequencing in families at high risk for Hodgkin lymphoma: identification of a predisposing mutation in the KDR gene. Haematologica 2016; 101:853-60. [PMID: 27365461 PMCID: PMC5004465 DOI: 10.3324/haematol.2015.135475] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 01/07/2016] [Indexed: 01/30/2023] Open
Abstract
Hodgkin lymphoma shows strong familial aggregation but no major susceptibility genes have been identified to date. The goal of this study was to identify high-penetrance variants using whole exome sequencing in 17 Hodgkin lymphoma prone families with three or more affected cases or obligate carriers (69 individuals), followed by targeted sequencing in an additional 48 smaller HL families (80 individuals). Alignment and variant calling were performed using standard methods. Dominantly segregating, rare, coding or potentially functional variants were further prioritized based on predicted deleteriousness, conservation, and potential importance in lymphoid malignancy pathways. We selected 23 genes for targeted sequencing. Only the p.A1065T variant in KDR (kinase insert domain receptor) also known as VEGFR2 (vascular endothelial growth factor receptor 2) was replicated in two independent Hodgkin lymphoma families. KDR is a type III receptor tyrosine kinase, the main mediator of vascular endothelial growth factor induced proliferation, survival, and migration. Its activity is associated with several diseases including lymphoma. Functional experiments have shown that p.A1065T, located in the activation loop, can promote constitutive autophosphorylation on tyrosine in the absence of vascular endothelial growth factor and that the kinase activity was abrogated after exposure to kinase inhibitors. A few other promising mutations were identified but appear to be "private". In conclusion, in the largest sequenced cohort of Hodgkin lymphoma families to date, we identified a causal mutation in the KDR gene. While independent validation is needed, this mutation may increase downstream tumor cell proliferation activity and might be a candidate for targeted therapy.
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Affiliation(s)
- Melissa Rotunno
- Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Mary L McMaster
- Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Joseph Boland
- Cancer Genomics Research Laboratory, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Sara Bass
- Cancer Genomics Research Laboratory, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Xijun Zhang
- Cancer Genomics Research Laboratory, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Laurie Burdett
- Cancer Genomics Research Laboratory, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Belynda Hicks
- Cancer Genomics Research Laboratory, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Sarangan Ravichandran
- Advanced Biomedical Computing Center, Leidos Biomedical Research Inc.; Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Brian T Luke
- Advanced Biomedical Computing Center, Leidos Biomedical Research Inc.; Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Meredith Yeager
- Cancer Genomics Research Laboratory, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | | | - Paula L Hyland
- Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Alisa M Goldstein
- Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Stephen J Chanock
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Neil E Caporaso
- Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Margaret A Tucker
- Human Genetics Program, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Lynn R Goldin
- Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
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23
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Kamat MA, Bacolla A, Cooper DN, Chuzhanova N. A Role for Non-B DNA Forming Sequences in Mediating Microlesions Causing Human Inherited Disease. Hum Mutat 2015; 37:65-73. [PMID: 26466920 DOI: 10.1002/humu.22917] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/22/2015] [Indexed: 12/25/2022]
Abstract
Missense/nonsense mutations and microdeletions/microinsertions (<21 bp) represent ∼ 76% of all mutations causing human inherited disease, and their occurrence has been associated with sequence motifs (direct, inverted, and mirror repeats; G-quartets) capable of adopting non-B DNA structures. We found that a significant proportion (∼ 21%) of both microdeletions and microinsertions occur within direct repeats, and are explicable by slipped misalignment. A novel mutational mechanism, DNA triplex formation followed by DNA repair, may explain ∼ 5% of microdeletions and microinsertions at mirror repeats. Further, G-quartets, direct, and inverted repeats also appear to play a prominent role in mediating missense mutations, whereas only direct and inverted repeats mediate nonsense mutations. We suggest a mutational mechanism involving slipped strand mispairing, slipped structure formation, and DNA repair, to explain ∼ 15% of missense and ∼ 12% of nonsense mutations yielding perfect direct repeats from imperfect repeats, or the extension of existing direct repeats. Similar proportions of missense and nonsense mutations were explicable by hairpin/loop formation and DNA repair, yielding perfect inverted repeats from imperfect repeats. We also propose a model for single base-pair substitution based on one-electron oxidation reactions at G-quadruplex DNA. Overall, the proposed mechanisms provide support for a role for non-B DNA structures in human gene mutagenesis.
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Affiliation(s)
- Mihir Anant Kamat
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, UK
| | - Albino Bacolla
- Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
| | - David N Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, UK
| | - Nadia Chuzhanova
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, UK
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24
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Abstract
DNA damage is a constant threat to cells, causing cytotoxicity as well as inducing genetic alterations. The steady-state abundance of DNA lesions in a cell is minimized by a variety of DNA repair mechanisms, including DNA strand break repair, mismatch repair, nucleotide excision repair, base excision repair, and ribonucleotide excision repair. The efficiencies and mechanisms by which these pathways remove damage from chromosomes have been primarily characterized by investigating the processing of lesions at defined genomic loci, among bulk genomic DNA, on episomal DNA constructs, or using in vitro substrates. However, the structure of a chromosome is heterogeneous, consisting of heavily protein-bound heterochromatic regions, open regulatory regions, actively transcribed genes, and even areas of transient single stranded DNA. Consequently, DNA repair pathways function in a much more diverse set of chromosomal contexts than can be readily assessed using previous methods. Recent efforts to develop whole genome maps of DNA damage, repair processes, and even mutations promise to greatly expand our understanding of DNA repair and mutagenesis. Here we review the current efforts to utilize whole genome maps of DNA damage and mutation to understand how different chromosomal contexts affect DNA excision repair pathways.
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Affiliation(s)
- John J Wyrick
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA; Center for Reproductive Biology, Washington State University, Pullman, WA 99164, USA.
| | - Steven A Roberts
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164, USA.
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25
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Computational DNA hole spectroscopy: A new tool to predict mutation hotspots, critical base pairs, and disease 'driver' mutations. Sci Rep 2015; 5:13571. [PMID: 26310834 PMCID: PMC4550865 DOI: 10.1038/srep13571] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/30/2015] [Indexed: 01/05/2023] Open
Abstract
We report on a new technique, computational DNA hole spectroscopy, which creates spectra of electron hole probabilities vs. nucleotide position. A hole is a site of positive charge created when an electron is removed. Peaks in the hole spectrum depict sites where holes tend to localize and potentially trigger a base pair mismatch during replication. Our studies of mitochondrial DNA reveal a correlation between L-strand hole spectrum peaks and spikes in the human mutation spectrum. Importantly, we also find that hole peak positions that do not coincide with large variant frequencies often coincide with disease-implicated mutations and/or (for coding DNA) encoded conserved amino acids. This enables combining hole spectra with variant data to identify critical base pairs and potential disease 'driver' mutations. Such integration of DNA hole and variance spectra could ultimately prove invaluable for pinpointing critical regions of the vast non-protein-coding genome. An observed asymmetry in correlations, between the spectrum of human mtDNA variations and the L- and H-strand hole spectra, is attributed to asymmetric DNA replication processes that occur for the leading and lagging strands.
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26
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Temiz NA, Donohue DE, Bacolla A, Vasquez KM, Cooper DN, Mudunuri U, Ivanic J, Cer RZ, Yi M, Stephens RM, Collins JR, Luke BT. The somatic autosomal mutation matrix in cancer genomes. Hum Genet 2015; 134:851-64. [PMID: 26001532 PMCID: PMC4495249 DOI: 10.1007/s00439-015-1566-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 05/12/2015] [Indexed: 01/26/2023]
Abstract
DNA damage in somatic cells originates from both environmental and endogenous sources, giving rise to mutations through multiple mechanisms. When these mutations affect the function of critical genes, cancer may ensue. Although identifying genomic subsets of mutated genes may inform therapeutic options, a systematic survey of tumor mutational spectra is required to improve our understanding of the underlying mechanisms of mutagenesis involved in cancer etiology. Recent studies have presented genome-wide sets of somatic mutations as a 96-element vector, a procedure that only captures the immediate neighbors of the mutated nucleotide. Herein, we present a 32 × 12 mutation matrix that captures the nucleotide pattern two nucleotides upstream and downstream of the mutation. A somatic autosomal mutation matrix (SAMM) was constructed from tumor-specific mutations derived from each of 909 individual cancer genomes harboring a total of 10,681,843 single-base substitutions. In addition, mechanistic template mutation matrices (MTMMs) representing oxidative DNA damage, ultraviolet-induced DNA damage, (5m)CpG deamination, and APOBEC-mediated cytosine mutation, are presented. MTMMs were mapped to the individual tumor SAMMs to determine the maximum contribution of each mutational mechanism to the overall mutation pattern. A Manhattan distance across all SAMM elements between any two tumor genomes was used to determine their relative distance. Employing this metric, 89.5% of all tumor genomes were found to have a nearest neighbor from the same tissue of origin. When a distance-dependent 6-nearest neighbor classifier was used, 10.4% of the SAMMs had an Undetermined tissue of origin, and 92.2% of the remaining SAMMs were assigned to the correct tissue of origin. [corrected]. Thus, although tumors from different tissues may have similar mutation patterns, their SAMMs often display signatures that are characteristic of specific tissues.
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Affiliation(s)
- Nuri A. Temiz
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
- />Masonic Cancer Center, University of Minnesota, 2-120 CCRB, 2231 6th St SE, Minneapolis, MN 55455 USA
| | - Duncan E. Donohue
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
- />US Army Medical Research and Material Command, 568 Doughten Dr., Fort Detrick, Frederick, MD 21702 USA
| | - Albino Bacolla
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
- />Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX 78723 USA
| | - Karen M. Vasquez
- />Division of Pharmacology and Toxicology, The University of Texas at Austin, Austin, TX 78723 USA
| | - David N. Cooper
- />Institute of Medical Genetics, School of Medicine, Cardiff University, Cardiff, CF14 4XN UK
| | - Uma Mudunuri
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
| | - Joseph Ivanic
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
| | - Regina Z. Cer
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
- />Naval Medical Research Center-Frederick, 8400 Research Plaza, Fort Detrick, Frederick, MD 21702 USA
| | - Ming Yi
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
| | - Robert M. Stephens
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
| | - Jack R. Collins
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
| | - Brian T. Luke
- />In Silico Research Centers of Excellence, Advanced Biomedical Computing Center, Information Systems Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., P.O. Box B, Frederick, MD 21702 USA
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27
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Bacolla A, Zhu X, Chen H, Howells K, Cooper DN, Vasquez KM. Local DNA dynamics shape mutational patterns of mononucleotide repeats in human genomes. Nucleic Acids Res 2015; 43:5065-80. [PMID: 25897114 PMCID: PMC4446427 DOI: 10.1093/nar/gkv364] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 04/07/2015] [Indexed: 12/13/2022] Open
Abstract
Single base substitutions (SBSs) and insertions/deletions are critical for generating population diversity and can lead both to inherited disease and cancer. Whereas on a genome-wide scale SBSs are influenced by cellular factors, on a fine scale SBSs are influenced by the local DNA sequence-context, although the role of flanking sequence is often unclear. Herein, we used bioinformatics, molecular dynamics and hybrid quantum mechanics/molecular mechanics to analyze sequence context-dependent mutagenesis at mononucleotide repeats (A-tracts and G-tracts) in human population variation and in cancer genomes. SBSs and insertions/deletions occur predominantly at the first and last base-pairs of A-tracts, whereas they are concentrated at the second and third base-pairs in G-tracts. These positions correspond to the most flexible sites along A-tracts, and to sites where a ‘hole’, generated by the loss of an electron through oxidation, is most likely to be localized in G-tracts. For A-tracts, most SBSs occur in the direction of the base-pair flanking the tracts. We conclude that intrinsic features of local DNA structure, i.e. base-pair flexibility and charge transfer, render specific nucleotides along mononucleotide runs susceptible to base modification, which then yields mutations. Thus, local DNA dynamics contributes to phenotypic variation and disease in the human population.
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Affiliation(s)
- Albino Bacolla
- Division of Pharmacology and Toxicology, College of Pharmacy, Dell Pediatric Research Institute, The University of Texas at Austin, 1400 Barbara Jordan Boulevard, Austin, TX 78723, USA
| | - Xiao Zhu
- Texas Advanced Computing Center, Austin, TX 78758-4497, USA
| | - Hanning Chen
- Department of Chemistry, George Washington University, 725 21st Street, NW, Washington, DC 20052, USA
| | - Katy Howells
- Institute of Medical Genetics, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - David N Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Karen M Vasquez
- Division of Pharmacology and Toxicology, College of Pharmacy, Dell Pediatric Research Institute, The University of Texas at Austin, 1400 Barbara Jordan Boulevard, Austin, TX 78723, USA
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28
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Abstract
A role for somatic mutations in carcinogenesis is well accepted, but the degree to which mutation rates influence cancer initiation and development is under continuous debate. Recently accumulated genomic data have revealed that thousands of tumour samples are riddled by hypermutation, broadening support for the idea that many cancers acquire a mutator phenotype. This major expansion of cancer mutation data sets has provided unprecedented statistical power for the analysis of mutation spectra, which has confirmed several classical sources of mutation in cancer, highlighted new prominent mutation sources (such as apolipoprotein B mRNA editing enzyme catalytic polypeptide-like (APOBEC) enzymes) and empowered the search for cancer drivers. The confluence of cancer mutation genomics and mechanistic insight provides great promise for understanding the basic development of cancer through mutations.
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29
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Du X, Gertz EM, Wojtowicz D, Zhabinskaya D, Levens D, Benham CJ, Schäffer AA, Przytycka TM. Potential non-B DNA regions in the human genome are associated with higher rates of nucleotide mutation and expression variation. Nucleic Acids Res 2014; 42:12367-79. [PMID: 25336616 PMCID: PMC4227770 DOI: 10.1093/nar/gku921] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
While individual non-B DNA structures have been shown to impact gene expression, their broad regulatory role remains elusive. We utilized genomic variants and expression quantitative trait loci (eQTL) data to analyze genome-wide variation propensities of potential non-B DNA regions and their relation to gene expression. Independent of genomic location, these regions were enriched in nucleotide variants. Our results are consistent with previously observed mutagenic properties of these regions and counter a previous study concluding that G-quadruplex regions have a reduced frequency of variants. While such mutagenicity might undermine functionality of these elements, we identified in potential non-B DNA regions a signature of negative selection. Yet, we found a depletion of eQTL-associated variants in potential non-B DNA regions, opposite to what might be expected from their proposed regulatory role. However, we also observed that genes downstream of potential non-B DNA regions showed higher expression variation between individuals. This coupling between mutagenicity and tolerance for expression variability of downstream genes may be a result of evolutionary adaptation, which allows reconciling mutagenicity of non-B DNA structures with their location in functionally important regions and their potential regulatory role.
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Affiliation(s)
- Xiangjun Du
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - E Michael Gertz
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Damian Wojtowicz
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Dina Zhabinskaya
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Levens
- UC Davis Genome Center, University of California Davis, Davis, CA 95616, USA
| | - Craig J Benham
- Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alejandro A Schäffer
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Teresa M Przytycka
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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30
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Bacolla A, Cooper DN, Vasquez KM. Mechanisms of base substitution mutagenesis in cancer genomes. Genes (Basel) 2014; 5:108-46. [PMID: 24705290 PMCID: PMC3978516 DOI: 10.3390/genes5010108] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 02/07/2014] [Accepted: 02/11/2014] [Indexed: 01/24/2023] Open
Abstract
Cancer genome sequence data provide an invaluable resource for inferring the key mechanisms by which mutations arise in cancer cells, favoring their survival, proliferation and invasiveness. Here we examine recent advances in understanding the molecular mechanisms responsible for the predominant type of genetic alteration found in cancer cells, somatic single base substitutions (SBSs). Cytosine methylation, demethylation and deamination, charge transfer reactions in DNA, DNA replication timing, chromatin status and altered DNA proofreading activities are all now known to contribute to the mechanisms leading to base substitution mutagenesis. We review current hypotheses as to the major processes that give rise to SBSs and evaluate their relative relevance in the light of knowledge acquired from cancer genome sequencing projects and the study of base modifications, DNA repair and lesion bypass. Although gene expression data on APOBEC3B enzymes provide support for a role in cancer mutagenesis through U:G mismatch intermediates, the enzyme preference for single-stranded DNA may limit its activity genome-wide. For SBSs at both CG:CG and YC:GR sites, we outline evidence for a prominent role of damage by charge transfer reactions that follow interactions of the DNA with reactive oxygen species (ROS) and other endogenous or exogenous electron-abstracting molecules.
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Affiliation(s)
- Albino Bacolla
- Dell Pediatric Research Institute, Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, 1400 Barbara Jordan Blvd., Austin, TX 78723, USA.
| | - David N Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK.
| | - Karen M Vasquez
- Dell Pediatric Research Institute, Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, 1400 Barbara Jordan Blvd., Austin, TX 78723, USA.
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