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Wang Z, Cui R, Liu L, Li L, Li Z, Liu X, Guo Y. Nanopore-Based Single-Molecule Investigation of Cation Effect on the i-Motif Structure. J Phys Chem B 2024. [PMID: 38959208 DOI: 10.1021/acs.jpcb.4c02021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The i-motif, a secondary structure of a four-helix formed by cytosine-rich DNA (i-DNA) through C-C+ base pairing, is prevalent in human telomeres and promoters. This structure creates steric hindrance, thereby inhibiting both gene expression and protein coding. The conformation of i-DNA is intricately linked to the intracellular ionic environment. Hence, investigating its conformation under various ion conditions holds significant importance. In this study, we explored the impact of cations on the i-motif structure at the single-molecule level using the α-hemolysin (α-HL) nanochannel. Our findings reveal that the ability of i-DNA to fold into the i-motif structure follows the order Cs+ > Na+ > K+ > Li+ for monovalent cations. Furthermore, we observed the interconversion of single-stranded DNA (ss-DNA) and the i-motif structure at high and low concentrations of Mg2+ and Ba2+ electrolyte solutions. This study not only has the potential to extend the application of i-motif-based sensors in complex solution environments but also provides a new idea for the detection of metal ions.
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Affiliation(s)
- Zhenzhao Wang
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Rikun Cui
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Lili Liu
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Linna Li
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Zhen Li
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Xingtong Liu
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Yanli Guo
- Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry & Materials Science, Northwest University, Xi'an 710127, P. R. China
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2
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Zhou W, Wan W, Miao W, Bao Y, Liu Y, Jia G, Li C. K +-Specification with Flavone P0 Probe in a G-Quadruplex DNA. Anal Chem 2024; 96:10835-10840. [PMID: 38889097 DOI: 10.1021/acs.analchem.4c02368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
G-quadruplex (G4) DNA is considered as a prospective therapeutic target due to its potential biological significance. To understand G4 biological roles and function, a G4-specific fluorescent probe is necessary. However, it is difficult for versatile G4 to precisely recognize without perturbing their folding dynamics. Herein, we reported that flavone P0 can be a fluorescent probe for G4 DNA-specific recognition and have developed a highly selective detection of K+ ion by dimeric G4/P0 system. When comparing various nucleic acid structures, including G4, i-motif, ss/ds-DNA, and triplex, an apparent fluorescence enhancement is observed in the presence of G4 DNA for 85-fold, but only 8-fold for non-G4 DNA. Furthermore, based on fluorescent probe of flavone P0 for G4 DNA screening, the noncovalent dimeric G4/P0 system is exploited as a K+ sensor, that selectively responds to K+ with a 513-fold fluorescence enhancement and a detection range for K+ ion concentration from 0 to 500 mM. This K+ sensor also has a remarkably anti-interference ability for other metal cations, especially for a high concentration of Na+. These results have demonstrated that flavone P0 is an efficient tool for monitoring G-quadruplex DNA and endows flavone P0 with bioanalytical and medicinal applications.
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Affiliation(s)
- Wenqin Zhou
- State Key Laboratory of Catalysis, Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian 116023, China
| | - Wang Wan
- Key Laboratory of Separation Science for Analytical Chemistry, Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian 116023, China
| | - Wenhui Miao
- State Key Laboratory of Catalysis, Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian 116023, China
| | - Yu Bao
- State Key Laboratory of Catalysis, Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian 116023, China
| | - Yu Liu
- Key Laboratory of Separation Science for Analytical Chemistry, Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian 116023, China
| | - Guoqing Jia
- State Key Laboratory of Catalysis, Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian 116023, China
| | - Can Li
- State Key Laboratory of Catalysis, Chinese Academy of Sciences, Dalian Institute of Chemical Physics, Dalian 116023, China
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Majocha MR, Jackson DE, Ha NH, Amin R, Pangrácová M, Ross CR, Yang HH, Lee MP, Hunter KW. Resf1 is a compound G4 quadruplex-associated tumor suppressor for triple negative breast cancer. PLoS Genet 2024; 20:e1011236. [PMID: 38722825 PMCID: PMC11081379 DOI: 10.1371/journal.pgen.1011236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 03/27/2024] [Indexed: 05/13/2024] Open
Abstract
Patients with ER-negative breast cancer have the worst prognosis of all breast cancer subtypes, often experiencing rapid recurrence or progression to metastatic disease shortly after diagnosis. Given that metastasis is the primary cause of mortality in most solid tumors, understanding metastatic biology is crucial for effective intervention. Using a mouse systems genetics approach, we previously identified 12 genes associated with metastatic susceptibility. Here, we extend those studies to identify Resf1, a poorly characterized gene, as a novel metastasis susceptibility gene in ER- breast cancer. Resf1 is a large, unstructured protein with an evolutionarily conserved intron-exon structure, but with poor amino acid conservation. CRISPR or gene trap mouse models crossed to the Polyoma Middle-T antigen genetically engineered mouse model (MMTV-PyMT) demonstrated that reduction of Resf1 resulted in a significant increase in tumor growth, a shortened overall survival time, and increased incidence and number of lung metastases, consistent with patient data. Furthermore, an analysis of matched tail and primary tissues revealed loss of the wildtype copy in tumor tissue, consistent with Resf1 being a tumor suppressor. Mechanistic analysis revealed a potential role of Resf1 in transcriptional control through association with compound G4 quadruplexes in expressed sequences, particularly those associated with ribosomal biogenesis. These results suggest that loss of Resf1 enhances tumor progression in ER- breast cancer through multiple alterations in both transcriptional and translational control.
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Affiliation(s)
- Megan R. Majocha
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington DC, United States of America
| | - Devin E. Jackson
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- Lombardi Comprehensive Cancer Center, Georgetown University, Washington DC, United States of America
| | - Ngoc-Han Ha
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ruhul Amin
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Marie Pangrácová
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Christina R. Ross
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Howard H. Yang
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Maxwell P. Lee
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kent W. Hunter
- Laboratory of Cancer Biology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
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4
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Gómez-Bra A, Gude L, Arias-Pérez MS. Synthesis, structural study and antitumor activity of novel alditol-based imidazophenanthrolines (aldo-IPs). Bioorg Med Chem 2024; 99:117563. [PMID: 38215623 DOI: 10.1016/j.bmc.2023.117563] [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: 07/05/2023] [Revised: 11/17/2023] [Accepted: 12/18/2023] [Indexed: 01/14/2024]
Abstract
A series of 1H-imidazo [4,5-f][1,10] phenanthroline derivatives functionalized at 2-position with chiral, and conformationally flexible polyhydroxy alkyl chains derived from carbohydrates (alditol-based imidazophenanthrolines, aldo-IPs) is presented herein. These novel glycomimetics showed relevant and differential cytotoxic activity against several cultured tumor cell lines (PC3, HeLa and HT-29), dependent on the nature and stereochemistry of the polyhydroxy alkyl chain. The mannose-based aldo-IP demonstrated the higher cytotoxicity in the series, substantially better than cisplatin metallo-drug in all cell lines tested, and better than G-quadruplex ligand 360A in HeLa and HT29 cells. Cell cycle experiments and Annexin V-PI assays revealed that aldo-IPs induce apoptosis in HeLa cells. Initial study of DNA interactions by DNA FRET melting assays proved that the aldo-IPs produce only a slight thermal stabilization of DNA secondary structures, more pronounced in the case of quadruplex DNA. Viscosity titrations with CT dsDNA suggest that the compounds behave as DNA groove binders, whereas equilibrium dialysis assays showed that the compounds bind CT with Ka values in the range 104-105 M-1. The aldo-IP derivatives were obtained with synthetically useful yields through a feasible one-pot multistep process, by aerobic oxidative cyclization of 1,10-phenanthroline-5,6-diamine with a selection of unprotected aldoses using (NH4)2SO4 as promoter.
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Affiliation(s)
- Ana Gómez-Bra
- Universidad de Alcalá, Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), 28805-Alcalá de Henares, Madrid, Spain; Grupo DISCOBAC, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), Spain
| | - Lourdes Gude
- Universidad de Alcalá, Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), 28805-Alcalá de Henares, Madrid, Spain; Grupo DISCOBAC, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), Spain.
| | - María-Selma Arias-Pérez
- Universidad de Alcalá, Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), 28805-Alcalá de Henares, Madrid, Spain.
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5
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Rai R, Sodeinde T, Boston A, Chang S. Telomeres cooperate with the nuclear envelope to maintain genome stability. Bioessays 2024; 46:e2300184. [PMID: 38047499 DOI: 10.1002/bies.202300184] [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: 09/25/2023] [Revised: 11/12/2023] [Accepted: 11/14/2023] [Indexed: 12/05/2023]
Abstract
Mammalian telomeres have evolved safeguards to prevent their recognition as DNA double-stranded breaks by suppressing the activation of various DNA sensing and repair proteins. We have shown that the telomere-binding proteins TRF2 and RAP1 cooperate to prevent telomeres from undergoing aberrant homology-directed recombination by mediating t-loop protection. Our recent findings also suggest that mammalian telomere-binding proteins interact with the nuclear envelope to maintain chromosome stability. RAP1 interacts with nuclear lamins through KU70/KU80, and disruption of RAP1 and TRF2 function result in nuclear envelope rupture, promoting telomere-telomere recombination to form structures termed ultrabright telomeres. In this review, we discuss the importance of the interactions between shelterin components and the nuclear envelope to maintain telomere homeostasis and genome stability.
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Affiliation(s)
- Rekha Rai
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Tori Sodeinde
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Ava Boston
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Molecular, Cellular and Developmental Biology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sandy Chang
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut, USA
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, USA
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Tire B, Talibova G, Ozturk S. The crosstalk between telomeres and DNA repair mechanisms: an overview to mammalian somatic cells, germ cells, and preimplantation embryos. J Assist Reprod Genet 2024; 41:277-291. [PMID: 38165506 PMCID: PMC10894803 DOI: 10.1007/s10815-023-03008-2] [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: 07/10/2023] [Accepted: 12/12/2023] [Indexed: 01/03/2024] Open
Abstract
Telomeres are located at the ends of linear chromosomes and play a critical role in maintaining genomic stability by preventing premature activation of DNA repair mechanisms. Because of exposure to various genotoxic agents, telomeres can undergo shortening and genetic changes. In mammalian cells, the basic DNA repair mechanisms, including base excision repair, nucleotide excision repair, double-strand break repair, and mismatch repair, function in repairing potential damages in telomeres. If these damages are not repaired correctly in time, the unfavorable results such as apoptosis, cell cycle arrest, and cancerous transition may occur. During lifespan, mammalian somatic cells, male and female germ cells, and preimplantation embryos experience a number of telomeric damages. Herein, we comprehensively reviewed the crosstalk between telomeres and the DNA repair mechanisms in the somatic cells, germ cells, and embryos. Infertility development resulting from possible defects in this crosstalk is also discussed in the light of existing studies.
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Affiliation(s)
- Betul Tire
- Department of Histology and Embryology, Akdeniz University School of Medicine, Campus, 07070, Antalya, Turkey
| | - Gunel Talibova
- Department of Histology and Embryology, Akdeniz University School of Medicine, Campus, 07070, Antalya, Turkey
| | - Saffet Ozturk
- Department of Histology and Embryology, Akdeniz University School of Medicine, Campus, 07070, Antalya, Turkey.
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7
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Kastl M, Hersperger F, Kierdorf K, Paeschke K. Detection of G-Quadruplex DNA Structures in Macrophages. Methods Mol Biol 2024; 2713:453-462. [PMID: 37639141 DOI: 10.1007/978-1-0716-3437-0_30] [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] [Indexed: 08/29/2023]
Abstract
In addition to the canonical B-DNA conformation, DNA can fold into different secondary structures. Among them are G-quadruplex structures (G4s). G4 structures are very stable and can fold in specific guanine-rich regions in DNA and RNA. Different in silico, in vitro, and in cellulo experiments have shown that G4 structures form so far in all tested organisms. There are over 700,000 predicted G4s in higher eukaryotes, but it is so far assumed that not all will form at the same time. Their formation is dynamically regulated by proteins and is cell type-specific and even changes during the cell cycle or during different exogenous or endogenous stimuli (e.g., infection or developmental stages) can alter the G4 level. G4s have been shown to accumulate in cancer cells where they contribute to gene expression changes and the mutagenic burden of the tumor. Specific targeting of G4 structures to impact the expression of oncogenes is currently discussed as an anti-cancer treatment. In a tumor microenvironment, not only the tumor cells will be targeted by G4 stabilization but also immune cells such as macrophages. Although G4s were detected in multiple organisms and different cell types, only little is known about their role in immune cells. Here, we provide a detailed protocol to detect G4 formation in the nucleus of macrophages of vertebrates and invertebrates by microscopic imaging.
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Affiliation(s)
- Melanie Kastl
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Fabian Hersperger
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katrin Kierdorf
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
- CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Katrin Paeschke
- Department of Oncology, Hematology and Rheumatology, University Hospital Bonn, Bonn, Germany.
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany.
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Lopina OD, Sidorenko SV, Fedorov DA, Klimanova EA. G-Quadruplexes as Sensors of Intracellular Na+/K + Ratio: Potential Role in Regulation of Transcription and Translation. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:S262-S277. [PMID: 38621755 DOI: 10.1134/s0006297924140153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/06/2023] [Accepted: 11/11/2023] [Indexed: 04/17/2024]
Abstract
Data on the structure of G-quadruplexes, noncanonical nucleic acid forms, supporting an idea of their potential participation in regulation of gene expression in response to the change in intracellular Na+i/K+i ratio are considered in the review. Structural variety of G-quadruplexes, role of monovalent cations in formation of this structure, and thermodynamic stability of G-quadruplexes are described. Data on the methods of their identification in the cells and biological functions of these structures are presented. Analysis of information about specific interactions of G-quadruplexes with some proteins was conducted, and their potential participation in the development of some pathological conditions, in particular, cancer and neurodegenerative diseases, is considered. Special attention is given to the plausible role of G-quadruplexes as sensors of intracellular Na+i/K+i ratio, because alteration of this parameter affects folding of G-quadruplexes changing their stability and, thereby, organization of the regulatory elements of nucleic acids. The data presented in the conclusion section demonstrate significant change in the expression of some early response genes under certain physiological conditions of cells and tissues depending on the intracellular Na+i/K+i ratio.
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Affiliation(s)
- Olga D Lopina
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia.
| | | | - Dmitry A Fedorov
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
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Irvin EM, Wang H. Single-molecule imaging of genome maintenance proteins encountering specific DNA sequences and structures. DNA Repair (Amst) 2023; 128:103528. [PMID: 37392578 PMCID: PMC10989508 DOI: 10.1016/j.dnarep.2023.103528] [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: 04/08/2023] [Revised: 06/08/2023] [Accepted: 06/21/2023] [Indexed: 07/03/2023]
Abstract
DNA repair pathways are tightly regulated processes that recognize specific hallmarks of DNA damage and coordinate lesion repair through discrete mechanisms, all within the context of a three-dimensional chromatin landscape. Dysregulation or malfunction of any one of the protein constituents in these pathways can contribute to aging and a variety of diseases. While the collective action of these many proteins is what drives DNA repair on the organismal scale, it is the interactions between individual proteins and DNA that facilitate each step of these pathways. In much the same way that ensemble biochemical techniques have characterized the various steps of DNA repair pathways, single-molecule imaging (SMI) approaches zoom in further, characterizing the individual protein-DNA interactions that compose each pathway step. SMI techniques offer the high resolving power needed to characterize the molecular structure and functional dynamics of individual biological interactions on the nanoscale. In this review, we highlight how our lab has used SMI techniques - traditional atomic force microscopy (AFM) imaging in air, high-speed AFM (HS-AFM) in liquids, and the DNA tightrope assay - over the past decade to study protein-nucleic acid interactions involved in DNA repair, mitochondrial DNA replication, and telomere maintenance. We discuss how DNA substrates containing specific DNA sequences or structures that emulate DNA repair intermediates or telomeres were generated and validated. For each highlighted project, we discuss novel findings made possible by the spatial and temporal resolution offered by these SMI techniques and unique DNA substrates.
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Affiliation(s)
| | - Hong Wang
- Toxicology Program, North Carolina State University, Raleigh, NC, USA; Physics Department, North Carolina State University, Raleigh, NC, USA; Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, USA.
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Han ZQ, Wen LN. Application of G-quadruplex targets in gastrointestinal cancers: Advancements, challenges and prospects. World J Gastrointest Oncol 2023; 15:1149-1173. [PMID: 37546556 PMCID: PMC10401460 DOI: 10.4251/wjgo.v15.i7.1149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 04/11/2023] [Accepted: 05/08/2023] [Indexed: 07/12/2023] Open
Abstract
Genomic instability and inflammation are considered to be two enabling characteristics that support cancer development and progression. G-quadruplex structure is a key element that contributes to genomic instability and inflammation. G-quadruplexes were once regarded as simply an obstacle that can block the transcription of oncogenes. A ligand targeting G-quadruplexes was found to have anticancer activity, making G-quadruplexes potential anticancer targets. However, further investigation has revealed that G-quadruplexes are widely distributed throughout the human genome and have many functions, such as regulating DNA replication, DNA repair, transcription, translation, epigenetics, and inflammatory response. G-quadruplexes play double regulatory roles in transcription and translation. In this review, we focus on G-quadruplexes as novel targets for the treatment of gastrointestinal cancers. We summarize the application basis of G-quadruplexes in gastrointestinal cancers, including their distribution sites, structural characteristics, and physiological functions. We describe the current status of applications for the treatment of esophageal cancer, pancreatic cancer, hepatocellular carcinoma, gastric cancer, colorectal cancer, and gastrointestinal stromal tumors, as well as the associated challenges. Finally, we review the prospective clinical applications of G-quadruplex targets, providing references for targeted treatment strategies in gastrointestinal cancers.
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Affiliation(s)
- Zong-Qiang Han
- Department of Laboratory Medicine, Beijing Xiaotangshan Hospital, Beijing 102211, China
| | - Li-Na Wen
- Department of Clinical Nutrition, Beijing Shijitan Hospital, Capital Medical University, Beijing 100038, China
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11
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Tire B, Ozturk S. Potential effects of assisted reproductive technology on telomere length and telomerase activity in human oocytes and early embryos. J Ovarian Res 2023; 16:130. [PMID: 37400833 DOI: 10.1186/s13048-023-01211-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 06/17/2023] [Indexed: 07/05/2023] Open
Abstract
Telomeres are repetitive DNA sequences at eukaryotic chromosome ends and function in maintaining genome integrity and stability. These unique structures undergo shortening due to various factors including biological aging, consecutive DNA replication, oxidative stress, and genotoxic agents. Shortened telomeres can be lengthened by the enzyme telomerase and alternative lengthening of telomeres in germ cells, early embryos, stem cells, and activated lymphocytes. If telomeres reach to critical length, it may lead to genomic instability, chromosome segregation defects, aneuploidy, and apoptosis. These phenotypes also occur in the oocytes and early embryos, produced using assisted reproductive technologies (ARTs). Thus, a number of studies have examined the potential effects of ART applications such as ovarian stimulation, culture conditions, and cryopreservation procedures on telomeres. Herein, we comprehensively reviewed impacts of these applications on telomere length and telomerase activity in ART-derived oocytes and embryos. Further, we discussed use of these parameters in ART centers as a biomarker in determining oocyte and embryo quality.
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Affiliation(s)
- Betul Tire
- Department of Histology and Embryology, Akdeniz University School of Medicine, Campus, 07070, Antalya, Turkey
| | - Saffet Ozturk
- Department of Histology and Embryology, Akdeniz University School of Medicine, Campus, 07070, Antalya, Turkey.
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12
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Vijay Kumar MJ, Morales R, Tsvetkov AS. G-quadruplexes and associated proteins in aging and Alzheimer's disease. FRONTIERS IN AGING 2023; 4:1164057. [PMID: 37323535 PMCID: PMC10267416 DOI: 10.3389/fragi.2023.1164057] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/17/2023] [Indexed: 06/17/2023]
Abstract
Aging is a prominent risk factor for many neurodegenerative disorders, such as Alzheimer's disease (AD). Alzheimer's disease is characterized by progressive cognitive decline, memory loss, and neuropsychiatric and behavioral symptoms, accounting for most of the reported dementia cases. This disease is now becoming a major challenge and burden on modern society, especially with the aging population. Over the last few decades, a significant understanding of the pathophysiology of AD has been gained by studying amyloid deposition, hyperphosphorylated tau, synaptic dysfunction, oxidative stress, calcium dysregulation, and neuroinflammation. This review focuses on the role of non-canonical secondary structures of DNA/RNA G-quadruplexes (G4s, G4-DNA, and G4-RNA), G4-binding proteins (G4BPs), and helicases, and their roles in aging and AD. Being critically important for cellular function, G4s are involved in the regulation of DNA and RNA processes, such as replication, transcription, translation, RNA localization, and degradation. Recent studies have also highlighted G4-DNA's roles in inducing DNA double-strand breaks that cause genomic instability and G4-RNA's participation in regulating stress granule formation. This review emphasizes the significance of G4s in aging processes and how their homeostatic imbalance may contribute to the pathophysiology of AD.
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Affiliation(s)
- M. J. Vijay Kumar
- The Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX, United States
| | - Rodrigo Morales
- The Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX, United States
- Centro Integrativo de Biologia y Quimica Aplicada (CIBQA), Universidad Bernardo O’Higgins, Santiago, Chile
| | - Andrey S. Tsvetkov
- The Department of Neurology, The University of Texas McGovern Medical School at Houston, Houston, TX, United States
- The University of Texas Graduate School of Biomedical Sciences, Houston, TX, United States
- UTHealth Consortium on Aging, The University of Texas McGovern Medical School, Houston, TX, United States
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13
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Rai R, Biju K, Sun W, Sodeinde T, Al-Hiyasat A, Morgan J, Ye X, Li X, Chen Y, Chang S. Homology directed telomere clustering, ultrabright telomere formation and nuclear envelope rupture in cells lacking TRF2 B and RAP1. Nat Commun 2023; 14:2144. [PMID: 37059728 PMCID: PMC10104862 DOI: 10.1038/s41467-023-37761-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 03/30/2023] [Indexed: 04/16/2023] Open
Abstract
Double-strand breaks (DSBs) due to genotoxic stress represent potential threats to genome stability. Dysfunctional telomeres are recognized as DSBs and are repaired by distinct DNA repair mechanisms. RAP1 and TRF2 are telomere binding proteins essential to protect telomeres from engaging in homology directed repair (HDR), but how this occurs remains unclear. In this study, we examined how the basic domain of TRF2 (TRF2B) and RAP1 cooperate to repress HDR at telomeres. Telomeres lacking TRF2B and RAP1 cluster into structures termed ultrabright telomeres (UTs). HDR factors localize to UTs, and UT formation is abolished by RNaseH1, DDX21 and ADAR1p110, suggesting that they contain DNA-RNA hybrids. Interaction between the BRCT domain of RAP1 and KU70/KU80 is also required to repress UT formation. Expressing TRF2∆B in Rap1-/- cells resulted in aberrant lamin A localization in the nuclear envelope and dramatically increased UT formation. Expressing lamin A phosphomimetic mutants induced nuclear envelope rupturing and aberrant HDR-mediated UT formation. Our results highlight the importance of shelterin and proteins in the nuclear envelope in repressing aberrant telomere-telomere recombination to maintain telomere homeostasis.
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Affiliation(s)
- Rekha Rai
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA.
| | - Kevin Biju
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
- Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Wenqi Sun
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Tori Sodeinde
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Amer Al-Hiyasat
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Jaida Morgan
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA
| | - Xianwen Ye
- University of Chinese Academy of Sciences, 100049, Beijing, China
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, 201210, China
| | - Xueqing Li
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Yong Chen
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai, 201210, China
| | - Sandy Chang
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, 330 Cedar Street, CT, 06520, USA.
- Department of Pathology, Yale University School of Medicine, 330 Cedar Street, New Haven, CT, 06520, USA.
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, 330 Cedar Street, New Haven, CT, 06520, USA.
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14
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Bahls B, Aljnadi IM, Emídio R, Mendes E, Paulo A. G-Quadruplexes in c-MYC Promoter as Targets for Cancer Therapy. Biomedicines 2023; 11:biomedicines11030969. [PMID: 36979947 PMCID: PMC10046398 DOI: 10.3390/biomedicines11030969] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/09/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Cancer is a societal burden demanding innovative approaches. A major problem with the conventional chemotherapeutic agents is their strong toxicity and other side effects due to their poor selectivity. Uncontrolled proliferation of cancer cells is due to mutations, deletions, or amplifications in genes (oncogenes) encoding for proteins that regulate cell growth and division, such as transcription factors, for example, c-MYC. The direct targeting of the c-MYC protein has been attempted but so far unsuccessfully, as it lacks a definite binding site for the modulators. Meanwhile, another approach has been explored since the discovery that G-quadruplex secondary DNA structures formed in the guanine-rich sequences of the c-MYC promoter region can downregulate the transcription of this oncogene. Here, we will overview the major achievements made in the last decades towards the discovery of a new class of anticancer drugs targeting G-quadruplexes in the c-MYC promoter of cancer cells.
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Affiliation(s)
- Bárbara Bahls
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Israa M Aljnadi
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Rita Emídio
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Eduarda Mendes
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Alexandra Paulo
- Faculty of Pharmacy, Research Institute for Medicines (iMed.Ulisboa), Universidade de Lisboa, 1649-003 Lisbon, Portugal
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15
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Gorini F, Ambrosio S, Lania L, Majello B, Amente S. The Intertwined Role of 8-oxodG and G4 in Transcription Regulation. Int J Mol Sci 2023; 24:ijms24032031. [PMID: 36768357 PMCID: PMC9916577 DOI: 10.3390/ijms24032031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/11/2023] [Accepted: 01/14/2023] [Indexed: 01/22/2023] Open
Abstract
The guanine base in nucleic acids is, among the other bases, the most susceptible to being converted into 8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) when exposed to reactive oxygen species. In double-helix DNA, 8-oxodG can pair with adenine; hence, it may cause a G > T (C > A) mutation; it is frequently referred to as a form of DNA damage and promptly corrected by DNA repair mechanisms. Moreover, 8-oxodG has recently been redefined as an epigenetic factor that impacts transcriptional regulatory elements and other epigenetic modifications. It has been proposed that 8-oxodG exerts epigenetic control through interplay with the G-quadruplex (G4), a non-canonical DNA structure, in transcription regulatory regions. In this review, we focused on the epigenetic roles of 8-oxodG and the G4 and explored their interplay at the genomic level.
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Affiliation(s)
- Francesca Gorini
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, 80131 Naples, Italy
| | - Susanna Ambrosio
- Department of Biology, University of Naples Federico II, 80138 Naples, Italy
| | - Luigi Lania
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, 80131 Naples, Italy
| | - Barbara Majello
- Department of Biology, University of Naples Federico II, 80138 Naples, Italy
| | - Stefano Amente
- Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, 80131 Naples, Italy
- Correspondence:
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16
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Dual Targeting Topoisomerase/G-Quadruplex Agents in Cancer Therapy-An Overview. Biomedicines 2022; 10:biomedicines10112932. [PMID: 36428499 PMCID: PMC9687504 DOI: 10.3390/biomedicines10112932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/11/2022] [Accepted: 11/12/2022] [Indexed: 11/17/2022] Open
Abstract
Topoisomerase (Topo) inhibitors have long been known as clinically effective drugs, while G-quadruplex (G4)-targeting compounds are emerging as a promising new strategy to target tumor cells and could support personalized treatment approaches in the near future. G-quadruplex (G4) is a secondary four-stranded DNA helical structure constituted of guanine-rich nucleic acids, and its stabilization impairs telomere replication, triggering the activation of several protein factors at telomere levels, including Topos. Thus, the pharmacological intervention through the simultaneous G4 stabilization and Topos inhibition offers a new opportunity to achieve greater antiproliferative activity and circumvent cellular insensitivity and resistance. In this line, dual ligands targeting both Topos and G4 emerge as innovative, efficient agents in cancer therapy. Although the research in this field is still limited, to date, some chemotypes have been identified, showing this dual activity and an interesting pharmacological profile. This paper reviews the available literature on dual Topo inhibitors/G4 stabilizing agents, with particular attention to the structure-activity relationship studies correlating the dual activity with the cytotoxic activity.
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17
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Chang TR, Long X, Shastry S, Parks JW, Stone MD. Single-Molecule Mechanical Analysis of Strand Invasion in Human Telomere DNA. Biochemistry 2022; 61:1554-1560. [PMID: 35852986 PMCID: PMC9352315 DOI: 10.1021/acs.biochem.1c00448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Telomeres are essential
chromosome end capping structures that
safeguard the genome from dangerous DNA processing events. DNA strand
invasion occurs during vital transactions at telomeres, including
telomere length maintenance by the alternative lengthening of telomeres
(ALT) pathway. During telomeric strand invasion, a single-stranded
guanine-rich (G-rich) DNA invades at a complementary duplex telomere
repeat sequence, forming a displacement loop (D-loop) in which the
displaced DNA consists of the same G-rich sequence as the invading
single-stranded DNA. Single-stranded G-rich telomeric DNA readily
folds into stable, compact, structures called G-quadruplexes (GQs)
in vitro and is anticipated to form within the context of a D-loop;
however, evidence supporting this hypothesis is lacking. Here, we
report a magnetic tweezers assay that permits the controlled formation
of telomeric D-loops (TDLs) within uninterrupted duplex human telomere
DNA molecules of physiologically relevant lengths. Our results are
consistent with a model wherein the displaced single-stranded DNA
of a TDL fold into a GQ. This study provides new insight into telomere
structure and establishes a framework for the development of novel
therapeutics designed to target GQs at telomeres in cancer cells.
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Affiliation(s)
- Terren R. Chang
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High St, Santa Cruz, California 95064, United States
| | - Xi Long
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High St, Santa Cruz, California 95064, United States
| | - Shankar Shastry
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High St, Santa Cruz, California 95064, United States
- 10X Genomics, 6230 Stoneridge Mall Rd, Pleasanton, California 94588, United States
| | - Joseph W. Parks
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High St, Santa Cruz, California 95064, United States
- Invitae, 1400 16th St, San Francisco, California 94103, United States
| | - Michael D. Stone
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High St, Santa Cruz, California 95064, United States
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18
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Gratal P, Arias-Pérez MS, Gude L. 1H-imidazo[4,5-f][1,10]phenanthroline carbohydrate conjugates: synthesis, DNA interactions and cytotoxic activity. Bioorg Chem 2022; 125:105851. [DOI: 10.1016/j.bioorg.2022.105851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/05/2022] [Accepted: 04/29/2022] [Indexed: 11/02/2022]
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19
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Brickner JR, Garzon JL, Cimprich KA. Walking a tightrope: The complex balancing act of R-loops in genome stability. Mol Cell 2022; 82:2267-2297. [PMID: 35508167 DOI: 10.1016/j.molcel.2022.04.014] [Citation(s) in RCA: 81] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/28/2022] [Accepted: 04/10/2022] [Indexed: 12/14/2022]
Abstract
Although transcription is an essential cellular process, it is paradoxically also a well-recognized cause of genomic instability. R-loops, non-B DNA structures formed when nascent RNA hybridizes to DNA to displace the non-template strand as single-stranded DNA (ssDNA), are partially responsible for this instability. Yet, recent work has begun to elucidate regulatory roles for R-loops in maintaining the genome. In this review, we discuss the cellular contexts in which R-loops contribute to genomic instability, particularly during DNA replication and double-strand break (DSB) repair. We also summarize the evidence that R-loops participate as an intermediate during repair and may influence pathway choice to preserve genomic integrity. Finally, we discuss the immunogenic potential of R-loops and highlight their links to disease should they become pathogenic.
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Affiliation(s)
- Joshua R Brickner
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jada L Garzon
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Karlene A Cimprich
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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20
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Agahi M, Rahaie M. A novel DNA tweezers-based nanobiosensor for multiple detections of circulating exosomal microRNAs in breast cancer. Anal Biochem 2022; 651:114697. [PMID: 35487268 DOI: 10.1016/j.ab.2022.114697] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/04/2022] [Accepted: 04/24/2022] [Indexed: 11/25/2022]
Abstract
Breast cancer is the prevalent disease in women, and diagnosis of it in early stage and takes preventive measures is very critical. Recently, circulating microRNAs have emerged as promising early biomarkers of cancer. MiR-21 and miR-155 are two significant biomarkers that act as oncomir in breast cancer. In this study, to detect both microRNAs in one test simultaneously, a novel colorimetric nanobiosensor was developed upon the peroxidation property of a specific G-quadruplex nanostructure. The nanostructure forms a DNA Nano-Tweezers after self-assembly of three DNA oligonucleotides with target sequences, and TMB (2, 2'-azino-bis (3-ethylbenzothiazo-line-6-sulfonic acid)) is used as a reporter to produce color. The high sensitivity of the nanobiosensor was determined (in buffer and blood) using different concentrations of target sequences with a linear response range from 0 to 10 nM, and detection limit of 0.38 nM (R2 = 0.98). The method precisely detected target sequences from non-target sequences in both buffer and blood media. These findings demonstrate, the nanobiosensor is superior to most previous published works due to its simultaneous dual detection, simplicity, low response time, and cost. The analytical data is convenient for accurately use for clinical purposes to detect breast cancer in early stage, more significantly.
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Affiliation(s)
- Melika Agahi
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, 14399-57131, Iran
| | - Mahdi Rahaie
- Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran, 14399-57131, Iran.
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21
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Wang MQ, Li HY, Cao HW, Lang XX, Chen YS. Selective c-MYC G4 DNA recognition based on a fluorescent light-up probe with disaggregation-induced emission characteristics. J Mater Chem B 2022; 10:7772-7779. [DOI: 10.1039/d2tb01316a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
c-MYC promoter is well-known as an important oncogene, whose overexpression leads to ∼80% of all solid tumors. The four-stranded G4 present in the c-MYC promoter has been shown to play...
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22
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Kaur P, Barnes R, Pan H, Detwiler AC, Liu M, Mahn C, Hall J, Messenger Z, You C, Piehler J, Smart R, Riehn R, Opresko PL, Wang H. TIN2 is an architectural protein that facilitates TRF2-mediated trans- and cis-interactions on telomeric DNA. Nucleic Acids Res 2021; 49:13000-13018. [PMID: 34883513 PMCID: PMC8682769 DOI: 10.1093/nar/gkab1142] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/08/2021] [Indexed: 12/23/2022] Open
Abstract
The telomere specific shelterin complex, which includes TRF1, TRF2, RAP1, TIN2, TPP1 and POT1, prevents spurious recognition of telomeres as double-strand DNA breaks and regulates telomerase and DNA repair activities at telomeres. TIN2 is a key component of the shelterin complex that directly interacts with TRF1, TRF2 and TPP1. In vivo, the large majority of TRF1 and TRF2 are in complex with TIN2 but without TPP1 and POT1. Since knockdown of TIN2 also removes TRF1 and TRF2 from telomeres, previous cell-based assays only provide information on downstream effects after the loss of TRF1/TRF2 and TIN2. Here, we investigated DNA structures promoted by TRF2-TIN2 using single-molecule imaging platforms, including tracking of compaction of long mouse telomeric DNA using fluorescence imaging, atomic force microscopy (AFM) imaging of protein-DNA structures, and monitoring of DNA-DNA and DNA-RNA bridging using the DNA tightrope assay. These techniques enabled us to uncover previously unknown unique activities of TIN2. TIN2S and TIN2L isoforms facilitate TRF2-mediated telomeric DNA compaction (cis-interactions), dsDNA-dsDNA, dsDNA-ssDNA and dsDNA-ssRNA bridging (trans-interactions). Furthermore, TIN2 facilitates TRF2-mediated T-loop formation. We propose a molecular model in which TIN2 functions as an architectural protein to promote TRF2-mediated trans and cis higher-order nucleic acid structures at telomeres.
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Affiliation(s)
- Parminder Kaur
- Physics Department, North Carolina State University, Raleigh, NC27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27695, USA
| | - Ryan Barnes
- Department of Environmental and Occupational Health, University of Pittsburgh, UPMC Hillman Cancer Center, PA 15213, USA
| | - Hai Pan
- Physics Department, North Carolina State University, Raleigh, NC27695, USA
| | - Ariana C Detwiler
- Department of Environmental and Occupational Health, University of Pittsburgh, UPMC Hillman Cancer Center, PA 15213, USA
| | - Ming Liu
- Physics Department, North Carolina State University, Raleigh, NC27695, USA
| | - Chelsea Mahn
- Physics Department, North Carolina State University, Raleigh, NC27695, USA
| | - Jonathan Hall
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27695, USA
- Toxicology Program, North Carolina State University, Raleigh, NC27695, USA
| | - Zach Messenger
- Toxicology Program, North Carolina State University, Raleigh, NC27695, USA
| | - Changjiang You
- Department of Biology/Chemistry, Universität Osnabrück, Osnabrück 49076, Germany
| | - Jacob Piehler
- Department of Biology/Chemistry, Universität Osnabrück, Osnabrück 49076, Germany
| | - Robert C Smart
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27695, USA
- Toxicology Program, North Carolina State University, Raleigh, NC27695, USA
| | - Robert Riehn
- Physics Department, North Carolina State University, Raleigh, NC27695, USA
| | - Patricia L Opresko
- Department of Environmental and Occupational Health, University of Pittsburgh, UPMC Hillman Cancer Center, PA 15213, USA
| | - Hong Wang
- Physics Department, North Carolina State University, Raleigh, NC27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC 27695, USA
- Toxicology Program, North Carolina State University, Raleigh, NC27695, USA
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23
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Caterino M, Paeschke K. Action and function of helicases on RNA G-quadruplexes. Methods 2021; 204:110-125. [PMID: 34509630 PMCID: PMC9236196 DOI: 10.1016/j.ymeth.2021.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/02/2021] [Accepted: 09/07/2021] [Indexed: 12/12/2022] Open
Abstract
Methodological progresses and piling evidence prove the rG4 biology in vivo. rG4s step in virtually every aspect of RNA biology. Helicases unwinding of rG4s is a fine regulatory layer to the downstream processes and general cell homeostasis. The current knowledge is however limited to a few cell lines. The regulation of helicases themselves is delineating as a important question. Non-helicase rG4-processing proteins likely play a role.
The nucleic acid structure called G-quadruplex (G4) is currently discussed to function in nucleic acid-based mechanisms that influence several cellular processes. They can modulate the cellular machinery either positively or negatively, both at the DNA and RNA level. The majority of what we know about G4 biology comes from DNA G4 (dG4) research. RNA G4s (rG4), on the other hand, are gaining interest as researchers become more aware of their role in several aspects of cellular homeostasis. In either case, the correct regulation of G4 structures within cells is essential and demands specialized proteins able to resolve them. Small changes in the formation and unfolding of G4 structures can have severe consequences for the cells that could even stimulate genome instability, apoptosis or proliferation. Helicases are the most relevant negative G4 regulators, which prevent and unfold G4 formation within cells during different pathways. Yet, and despite their importance only a handful of rG4 unwinding helicases have been identified and characterized thus far. This review addresses the current knowledge on rG4s-processing helicases with a focus on methodological approaches. An example of a non-helicase rG4s-unwinding protein is also briefly described.
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Affiliation(s)
- Marco Caterino
- Department of Oncology, Hematology and Rheumatology, University Hospital Bonn, 53127 Bonn, Germany
| | - Katrin Paeschke
- Department of Oncology, Hematology and Rheumatology, University Hospital Bonn, 53127 Bonn, Germany.
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24
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Faria JRC. A nuclear enterprise: zooming in on nuclear organization and gene expression control in the African trypanosome. Parasitology 2021; 148:1237-1253. [PMID: 33407981 PMCID: PMC8311968 DOI: 10.1017/s0031182020002437] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 12/17/2022]
Abstract
African trypanosomes are early divergent protozoan parasites responsible for high mortality and morbidity as well as a great economic burden among the world's poorest populations. Trypanosomes undergo antigenic variation in their mammalian hosts, a highly sophisticated immune evasion mechanism. Their nuclear organization and mechanisms for gene expression control present several conventional features but also a number of striking differences to the mammalian counterparts. Some of these unorthodox characteristics, such as lack of controlled transcription initiation or enhancer sequences, render their monogenic antigen transcription, which is critical for successful antigenic variation, even more enigmatic. Recent technological developments have advanced our understanding of nuclear organization and gene expression control in trypanosomes, opening novel research avenues. This review is focused on Trypanosoma brucei nuclear organization and how it impacts gene expression, with an emphasis on antigen expression. It highlights several dedicated sub-nuclear bodies that compartmentalize specific functions, whilst outlining similarities and differences to more complex eukaryotes. Notably, understanding the mechanisms underpinning antigen as well as general gene expression control is of great importance, as it might help designing effective control strategies against these organisms.
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Affiliation(s)
- Joana R. C. Faria
- The Wellcome Trust Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, DundeeDD1 5EH, UK
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25
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Yang SY, Chang EYC, Lim J, Kwan HH, Monchaud D, Yip S, Stirling PC, Wong JMY. G-quadruplexes mark alternative lengthening of telomeres. NAR Cancer 2021; 3:zcab031. [PMID: 34316718 PMCID: PMC8294677 DOI: 10.1093/narcan/zcab031] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/29/2021] [Accepted: 07/05/2021] [Indexed: 11/12/2022] Open
Abstract
About 10-15% of all human cancer cells employ a telomerase-independent recombination-based telomere maintenance method, known as alternative lengthening of telomere (ALT), of which the full mechanism remains incompletely understood. While implicated in previous studies as the initiating signals for ALT telomere repair, the prevalence of non-canonical nucleic acid structures in ALT cancers remains unclear. Extending earlier reports, we observe higher levels of DNA/RNA hybrids (R-loops) in ALT-positive (ALT+) compared to telomerase-positive (TERT+) cells. Strikingly, we observe even more pronounced differences for an associated four-stranded nucleic acid structure, G-quadruplex (G4). G4 signals are found at the telomere and are broadly associated with telomere length and accompanied by DNA damage markers. We establish an interdependent relationship between ALT-associated G4s and R-loops and confirm that these two structures can be spatially linked into unique structures, G-loops, at the telomere. Additionally, stabilization of G4s and R-loops cooperatively enhances ALT-activity. However, co-stabilization at higher doses resulted in cytotoxicity in a synergistic manner. Nuclear G4 signals are significantly and reproducibly different between ALT+ and TERT+ low-grade glioma tumours. Together, we present G4 as a novel hallmark of ALT cancers with potential future applications as a convenient biomarker for identifying ALT+ tumours and as therapeutic targets.
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Affiliation(s)
- Sunny Y Yang
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
| | | | - Joanne Lim
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
| | - Harwood H Kwan
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
| | - David Monchaud
- Institut de Chimie Moléculaire, ICMUB CNRS UMR 6302, UBFC Dijon, 21078 Dijon, France
| | - Stephen Yip
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, V6T 2B5 Canada
| | | | - Judy M Y Wong
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, V6T 1Z3, Canada
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26
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Vohhodina J, Goehring LJ, Liu B, Kong Q, Botchkarev VV, Huynh M, Liu Z, Abderazzaq FO, Clark AP, Ficarro SB, Marto JA, Hatchi E, Livingston DM. BRCA1 binds TERRA RNA and suppresses R-Loop-based telomeric DNA damage. Nat Commun 2021; 12:3542. [PMID: 34112789 PMCID: PMC8192922 DOI: 10.1038/s41467-021-23716-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 05/11/2021] [Indexed: 12/13/2022] Open
Abstract
R-loop structures act as modulators of physiological processes such as transcription termination, gene regulation, and DNA repair. However, they can cause transcription-replication conflicts and give rise to genomic instability, particularly at telomeres, which are prone to forming DNA secondary structures. Here, we demonstrate that BRCA1 binds TERRA RNA, directly and physically via its N-terminal nuclear localization sequence, as well as telomere-specific shelterin proteins in an R-loop-, and a cell cycle-dependent manner. R-loop-driven BRCA1 binding to CpG-rich TERRA promoters represses TERRA transcription, prevents TERRA R-loop-associated damage, and promotes its repair, likely in association with SETX and XRN2. BRCA1 depletion upregulates TERRA expression, leading to overly abundant TERRA R-loops, telomeric replication stress, and signs of telomeric aberrancy. Moreover, BRCA1 mutations within the TERRA-binding region lead to an excess of TERRA-associated R-loops and telomeric abnormalities. Thus, normal BRCA1/TERRA binding suppresses telomere-centered genome instability. BRCA1-mediated resolution of R-loops has previously been described. Here the authors reveal a functional association of BRCA1 with TERRA RNA at telomeres, which develops in an R-loop-, and a cell cycle-dependent manner.
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Affiliation(s)
- Jekaterina Vohhodina
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Genetics, Harvard Medical School, Boston, MA, USA.
| | - Liana J Goehring
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Ben Liu
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Qing Kong
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Vladimir V Botchkarev
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Mai Huynh
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Zhiqi Liu
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Fieda O Abderazzaq
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Allison P Clark
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Scott B Ficarro
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jarrod A Marto
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Elodie Hatchi
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - David M Livingston
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Genetics, Harvard Medical School, Boston, MA, USA.
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Müller D, Bessi I, Richter C, Schwalbe H. The Folding Landscapes of Human Telomeric RNA and DNA G-Quadruplexes are Markedly Different. Angew Chem Int Ed Engl 2021; 60:10895-10901. [PMID: 33539622 PMCID: PMC8252441 DOI: 10.1002/anie.202100280] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/04/2021] [Indexed: 01/23/2023]
Abstract
We investigated the folding kinetics of G‐quadruplex (G4) structures by comparing the K+‐induced folding of an RNA G4 derived from the human telomeric repeat‐containing RNA (TERRA25) with a sequence homologous DNA G4 (wtTel25) using CD spectroscopy and real‐time NMR spectroscopy. While DNA G4 folding is biphasic, reveals kinetic partitioning and involves kinetically favoured off‐pathway intermediates, RNA G4 folding is faster and monophasic. The differences in kinetics are correlated to the differences in the folded conformations of RNA vs. DNA G4s, in particular with regard to the conformation around the glycosidic torsion angle χ that uniformly adopts anti conformations for RNA G4s and both, syn and anti conformation for DNA G4s. Modified DNA G4s with 19F bound to C2′ in arabino configuration adopt exclusively anti conformations for χ. These fluoro‐modified DNA (antiTel25) reveal faster folding kinetics and monomorphic conformations similar to RNA G4s, suggesting the correlation between folding kinetics and pathways with differences in χ angle preferences in DNA and RNA, respectively.
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Affiliation(s)
- Diana Müller
- Goethe University Frankfurt/Centre for Biomolecular Magnetic Resonance (BMRZ), Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438, Frankfurt am Main, Germany
| | - Irene Bessi
- Goethe University Frankfurt/Centre for Biomolecular Magnetic Resonance (BMRZ), Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438, Frankfurt am Main, Germany.,Present address: Julius-Maximilians-University Würzburg, Institute of Organic Chemistry, Am Hubland 16, 97074, Würzburg, Germany
| | - Christian Richter
- Goethe University Frankfurt/Centre for Biomolecular Magnetic Resonance (BMRZ), Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438, Frankfurt am Main, Germany
| | - Harald Schwalbe
- Goethe University Frankfurt/Centre for Biomolecular Magnetic Resonance (BMRZ), Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438, Frankfurt am Main, Germany
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28
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The Folding Landscapes of Human Telomeric RNA and DNA G‐Quadruplexes are Markedly Different. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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29
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The Long Linker Region of Telomere-Binding Protein TRF2 Is Responsible for Interactions with Lamins. Int J Mol Sci 2021; 22:ijms22073293. [PMID: 33804854 PMCID: PMC8036907 DOI: 10.3390/ijms22073293] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 12/15/2022] Open
Abstract
Telomere-binding factor 2 (TRF2) is part of the shelterin protein complex found at chromosome ends. Lamin A/C interacts with TRF2 and influences telomere position. TRF2 has an intrinsically disordered region between the ordered dimerization and DNA-binding domains. This domain is referred to as the long linker region of TRF2, or udTRF2. We suggest that udTRF2 might be involved in the interaction between TRF2 and lamins. The recombinant protein corresponding to the udTRF2 region along with polyclonal antibodies against this region were used in co-immunoprecipitation with purified lamina and nuclear extracts. Co-immunoprecipitation followed by Western blots and mass spectrometry indicated that udTRF2 interacts with lamins, preferably lamins A/C. The interaction did not involve any lamin-associated proteins, was not dependent on the post-translation modification of lamins, nor did it require their higher-order assembly. Besides lamins, a number of other udTRF2-interacting proteins were identified by mass spectrometry, including several heterogeneous nuclear ribonucleoproteins (hnRNP A2/B1, hnRNPA1, hnRNP A3, hnRNP K, hnRNP L, hnRNP M), splicing factors (SFPQ, NONO, SRSF1, and others), helicases (DDX5, DHX9, and Eif4a3l1), topoisomerase I, and heat shock protein 71, amongst others. Some of the identified interactors are known to be involved in telomere biology; the roles of the others remain to be investigated. Thus, the long linker region of TRF2 (udTRF2) is a regulatory domain responsible for the association between TRF2 and lamins and is involved in interactions with other proteins.
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Kosiol N, Juranek S, Brossart P, Heine A, Paeschke K. G-quadruplexes: a promising target for cancer therapy. Mol Cancer 2021; 20:40. [PMID: 33632214 PMCID: PMC7905668 DOI: 10.1186/s12943-021-01328-4] [Citation(s) in RCA: 215] [Impact Index Per Article: 71.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 02/01/2021] [Indexed: 12/13/2022] Open
Abstract
DNA and RNA can fold into a variety of alternative conformations. In recent years, a particular nucleic acid structure was discussed to play a role in malignant transformation and cancer development. This structure is called a G-quadruplex (G4). G4 structure formation can drive genome instability by creating mutations, deletions and stimulating recombination events. The importance of G4 structures in the characterization of malignant cells was currently demonstrated in breast cancer samples. In this analysis a correlation between G4 structure formation and an increased intratumor heterogeneity was identified. This suggests that G4 structures might allow breast cancer stratification and supports the identification of new personalized treatment options. Because of the stability of G4 structures and their presence within most human oncogenic promoters and at telomeres, G4 structures are currently tested as a therapeutic target to downregulate transcription or to block telomere elongation in cancer cells. To date, different chemical molecules (G4 ligands) have been developed that aim to target G4 structures. In this review we discuss and compare G4 function and relevance for therapeutic approaches and their impact on cancer development for three cancer entities, which differ significantly in their amount and type of mutations: pancreatic cancer, leukemia and malignant melanoma. G4 structures might present a promising new strategy to individually target tumor cells and could support personalized treatment approaches in the future.
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Affiliation(s)
- Nils Kosiol
- Department of Oncology, Hematology, Rheumatology and Immune-Oncology, University Hospital Bonn, 53127, Bonn, Germany
| | - Stefan Juranek
- Department of Oncology, Hematology, Rheumatology and Immune-Oncology, University Hospital Bonn, 53127, Bonn, Germany
| | - Peter Brossart
- Department of Oncology, Hematology, Rheumatology and Immune-Oncology, University Hospital Bonn, 53127, Bonn, Germany
| | - Annkristin Heine
- Department of Oncology, Hematology, Rheumatology and Immune-Oncology, University Hospital Bonn, 53127, Bonn, Germany
| | - Katrin Paeschke
- Department of Oncology, Hematology, Rheumatology and Immune-Oncology, University Hospital Bonn, 53127, Bonn, Germany.
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31
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Gratal PB, Quero JG, Pérez-Redondo A, Gándara Z, Gude L. PhenQE8, a Novel Ligand of the Human Telomeric Quadruplex. Int J Mol Sci 2021; 22:E749. [PMID: 33451070 PMCID: PMC7828518 DOI: 10.3390/ijms22020749] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/30/2020] [Accepted: 01/10/2021] [Indexed: 01/02/2023] Open
Abstract
A novel quadruplex ligand based on 1,10-phenanthroline and incorporating two guanyl hydrazone functionalities, PhenQE8, is reported herein. Synthetic access was gained in a two-step procedure with an overall yield of 61%. X-ray diffraction studies revealed that PhenQE8 can adopt an extended conformation that may be optimal to favor recognition of quadruplex DNA. DNA interactions with polymorphic G-quadruplex telomeric structures were studied by different techniques, such as Fluorescence resonance energy transfer (FRET) DNA melting assays, circular dichroism and equilibrium dialysis. Our results reveal that the novel ligand PhenQE8 can efficiently recognize the hybrid quadruplex structures of the human telomeric DNA, with high binding affinity and quadruplex/duplex selectivity. Moreover, the compound shows significant cytotoxic activity against a selected panel of cultured tumor cells (PC-3, HeLa and MCF-7), whereas its cytotoxicity is considerably lower in healthy human cells (HFF-1 and RPWE-1).
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Affiliation(s)
| | | | | | - Zoila Gándara
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química “Andrés M. del Río” (IQAR), Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain; (P.B.G.); (J.G.Q.); (A.P.-R.)
| | - Lourdes Gude
- Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química “Andrés M. del Río” (IQAR), Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain; (P.B.G.); (J.G.Q.); (A.P.-R.)
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32
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Andreeva DV, Tikhomirov AS, Shchekotikhin AE. Ligands of G-quadruplex nucleic acids. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr4968] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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33
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Platform- and label-free detection of lead ions in environmental and laboratory samples using G-quadraplex probes by circular dichroism spectroscopy. Sci Rep 2020; 10:20461. [PMID: 33235290 PMCID: PMC7686487 DOI: 10.1038/s41598-020-77449-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/13/2020] [Indexed: 12/15/2022] Open
Abstract
Guanine-rich quadruplex (G-QD) are formed by conversion of nucleotides with specific sequences by stabilization of positively charged K+ or Na+. These G-QD structures differentially absorb two-directional (right- and left-handed) circularly polarized light, which can discriminate the parallel or anti-parallel structures of G-QDs. In this study, G-QDs stabilized by Pb2+ were analyzed by a circular dichroism (CD) spectroscopy to determine Pb2+ concentration in water samples. Thrombin aptamer (TBA), PS2.M, human telomeric DNA (HTG), AGRO 100, and telomeric related sequence (T2) were studied to verify their applicability as probes for platform- and label-free detection of Pb2+ in environmental as well as laboratory samples. Among these nucleotides, TBA and PS2.M exhibited higher binding constants for Pb2+, 1.20-2.04 × 106/M at and 4.58 × 104-1.09 × 105/M at 100 micromolar and 100 mM K+ concentration, respectively. They also exhibited excellent selectivity for Pb2+ than for Al3+, Cu2+, Ni2+, Fe3+, Co2+, and Cr2+. When Pb2+ was spiked into an effluent sample from a wastewater treatment plant (WWTP), its existence was detected by CD spectroscopy following a simple addition of TBA or PS2.M. By the addition of TBA and PS2.M, the Pb2+ signals were observed in effluent samples over 0.5 micromolar (100 ppb) concentration. Furthermore, PS2.M caused a Pb2+-specific absorption band in the effluent sample without spiking of Pb2+, and could be induced to G-QD structure by the background Pb2+ concentration in the effluent, 0.159 micromolar concentration (3.30 ppb). Taken together, we propose that TBA and PS2.M are applicable as platform- and label-free detection probes for monitoring Pb2+ in environmental samples such as discharged effluent from local WWTPs, using CD spectroscopy.
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34
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Proshkina E, Shaposhnikov M, Moskalev A. Genome-Protecting Compounds as Potential Geroprotectors. Int J Mol Sci 2020; 21:E4484. [PMID: 32599754 PMCID: PMC7350017 DOI: 10.3390/ijms21124484] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 02/06/2023] Open
Abstract
Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.
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Affiliation(s)
- Ekaterina Proshkina
- Laboratory of Geroprotective and Radioprotective Technologies, Institute of Biology, Komi Science Centre, Ural Branch, Russian Academy of Sciences, 28 Kommunisticheskaya st., 167982 Syktyvkar, Russia; (E.P.); (M.S.)
| | - Mikhail Shaposhnikov
- Laboratory of Geroprotective and Radioprotective Technologies, Institute of Biology, Komi Science Centre, Ural Branch, Russian Academy of Sciences, 28 Kommunisticheskaya st., 167982 Syktyvkar, Russia; (E.P.); (M.S.)
| | - Alexey Moskalev
- Laboratory of Geroprotective and Radioprotective Technologies, Institute of Biology, Komi Science Centre, Ural Branch, Russian Academy of Sciences, 28 Kommunisticheskaya st., 167982 Syktyvkar, Russia; (E.P.); (M.S.)
- Pitirim Sorokin Syktyvkar State University, 55 Oktyabrsky prosp., 167001 Syktyvkar, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
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