1
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Lin H, Hassan Safdar M, Washburn S, S Akhand S, Dickerhoff J, Ayers M, Monteiro M, Solorio L, Yang D, Wendt MK. Fibroblast growth receptor 1 is regulated by G-quadruplex in metastatic breast cancer. Commun Biol 2024; 7:963. [PMID: 39122837 PMCID: PMC11316068 DOI: 10.1038/s42003-024-06602-x] [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: 09/11/2023] [Accepted: 07/18/2024] [Indexed: 08/12/2024] Open
Abstract
Limiting cellular plasticity is of key importance for the therapeutic targeting of metastatic breast cancer (MBC). Fibroblast growth receptor (FGFR) is a critical molecule in cellular plasticity and potent inhibitors of FGFR enzymatic activity have been developed, but kinase independent functions for this receptor also contribute to MBC progression. Herein, we evaluated several FGFR inhibitors and find that while FGFR-targeted kinase inhibitors are effective at blocking ligand-induced cell growth, dormant cells persist eventually giving rise to MBC progression. To more broadly target FGFR and cellular plasticity, we examined the FGFR1 proximal promoter, and found several sequences with potential to form G-quadruplex secondary structures. Circular dichroism was used to verify formation of G-quadruplex in the FGFR1 proximal promoter. Importantly, use of the clinical G-quadruplex-stabilizing compound, CX-5461, stabilized the FGFR1 G-quadruplex structures, blocked the transcriptional activity of the FGFR1 proximal promoter, decreased FGFR1 expression, and resulted in potent inhibition of pulmonary tumor formation. Overall, our findings suggest G-quadruplex-targeted compounds could be a potential therapeutic strategy to limit the cellular plasticity of FGFR1 overexpressing MBC.
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Affiliation(s)
- Hang Lin
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Muhammad Hassan Safdar
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Sarah Washburn
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Saeed S Akhand
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Jonathan Dickerhoff
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Mitchell Ayers
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
| | - Marvis Monteiro
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA
| | - Luis Solorio
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN, USA
- Department of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Danzhou Yang
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA.
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN, USA.
- Department of Chemistry, Purdue University, West Lafayette, IN, USA.
| | - Michael K Wendt
- Borch Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN, USA.
- Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN, USA.
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA, USA.
- Department of Internal Medicine, University of Iowa, Iowa City, IA, USA.
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2
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Kumar S, Biswas A, Sudhakar S, Kumari D, Pradeepkumar PI. Estrone-Based Derivatives Stabilize the c-MYC and c-KIT G-Quadruplex DNA Structures. ACS OMEGA 2024; 9:6616-6626. [PMID: 38371752 PMCID: PMC10870291 DOI: 10.1021/acsomega.3c07574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/20/2023] [Accepted: 11/28/2023] [Indexed: 02/20/2024]
Abstract
G-rich sequences are present across the genome and can fold to form dynamic secondary structures, namely, G-quadruplexes (G4). These structures play a pivotal role in regulating numerous biological processes including replication, transcription, and translation. Therefore, targeting these structures using molecular scaffolds is an attractive approach to modulating their functions. Herein, we report the synthesis of three estrone-based derivatives (Est-1, Est-2, and Est-3) with a nonplanar core and a cationic alkyl side chain as G4 stabilizers. CD melting and polymerase stop assay results indicate that these ligands preferentially stabilize parallel c-MYC and c-KIT1 G4s over the other G4s and duplex DNAs. The ligand Est-3 shows cytotoxicity against cancer cell lines and effectively downregulates the c-KIT gene in HepG2 cell lines. Molecular modeling and dynamics studies showed that the ligand prefers stacking over the 5'-quartet of c-MYC G4 using the aromatic ring of the ligand. Overall, the findings of this study demonstrate that even G4 ligands can accommodate nonplanar scaffolds, which opens up new avenues for ligand design.
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Affiliation(s)
- Satendra Kumar
- Department of Chemistry, Indian
Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Annyesha Biswas
- Department of Chemistry, Indian
Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sruthi Sudhakar
- Department of Chemistry, Indian
Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Divya Kumari
- Department of Chemistry, Indian
Institute of Technology Bombay, Powai, Mumbai 400076, India
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3
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Jana J, Vianney YM, Weisz K. Impact of loop length and duplex extensions on the design of hybrid-type G-quadruplexes. Chem Commun (Camb) 2024; 60:854-857. [PMID: 38131370 DOI: 10.1039/d3cc05625b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
A G-rich core sequence G3-TCA-G3-T1,2-G3-T1,2-G3 can be designed to fold into a parallel or into two different (3+1) hybrid-type G-quadruplexes, among them an elusive topology with one lateral followed by two propeller loops. Favored folds can be rationalized based on the number of intervening thymidines and on additional complementary flanking sequences.
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Affiliation(s)
- Jagannath Jana
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff Str. 4, Greifswald D-17489, Germany.
| | - Yoanes Maria Vianney
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff Str. 4, Greifswald D-17489, Germany.
| | - Klaus Weisz
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff Str. 4, Greifswald D-17489, Germany.
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4
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Dickerhoff J, Jang J, Yang D. Best method to determine DNA G-quadruplex folding: The 1H- 13C HSQC NMR experiment. Methods 2024; 221:35-41. [PMID: 38029869 PMCID: PMC10872514 DOI: 10.1016/j.ymeth.2023.11.013] [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: 09/22/2023] [Revised: 11/23/2023] [Accepted: 11/25/2023] [Indexed: 12/01/2023] Open
Abstract
NMR spectroscopy is the major method for G-quadruplex structure determination under physiologically relevant solution conditions. Unlike duplex B-DNA, in which all nucleotides adopt an anti glycosidic conformation, the core tetrad-guanines in a G-quadruplex can adopt anti or syn glycosidic conformation depending on the folding structure. An experimental method that can clearly and unambiguously determine syn and anti tetrad-Gs in a G-quadruplex is highly desirable and necessary. In the present study, we exploit the advantages of the 1H-13C HSQC experiment to determine tetrad-G's glycosidic conformation and thus folding topology of G-quadruplexes. We use several examples to demonstrate the clear and straightforward determination of the guanine glycosidic conformations and G-quadruplex folding structures. Moreover, 1H-13C HSQC data can readily identify adenine H2 resonances as well as determine unusual syn conformation in loop and flanking sequences, a challenging task by standard 2D NOESY.
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Affiliation(s)
- Jonathan Dickerhoff
- Purdue University, College of Pharmacy, Borch Department of Medicinal Chemistry and Molecular Pharmacology, 575 W Stadium Ave, West Lafayette, IN 47907, USA
| | - Jinho Jang
- Purdue University, College of Pharmacy, Borch Department of Medicinal Chemistry and Molecular Pharmacology, 575 W Stadium Ave, West Lafayette, IN 47907, USA
| | - Danzhou Yang
- Purdue University, College of Pharmacy, Borch Department of Medicinal Chemistry and Molecular Pharmacology, 575 W Stadium Ave, West Lafayette, IN 47907, USA; Purdue Institute for Cancer Research, 201 S University St, West Lafayette, IN 47906, USA; Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
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5
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Romano F, Di Porzio A, Iaccarino N, Riccardi G, Di Lorenzo R, Laneri S, Pagano B, Amato J, Randazzo A. G-quadruplexes in cancer-related gene promoters: from identification to therapeutic targeting. Expert Opin Ther Pat 2023; 33:745-773. [PMID: 37855085 DOI: 10.1080/13543776.2023.2271168] [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: 06/26/2023] [Accepted: 10/11/2023] [Indexed: 10/20/2023]
Abstract
INTRODUCTION Guanine-rich DNA sequences can fold into four-stranded noncanonical secondary structures called G-quadruplexes (G4s) which are widely distributed in functional regions of the human genome, such as telomeres and gene promoter regions. Compelling evidence suggests their involvement in key genome functions such as gene expression and genome stability. Notably, the abundance of G4-forming sequences near transcription start sites suggests their potential involvement in regulating oncogenes. AREAS COVERED This review provides an overview of current knowledge on G4s in human oncogene promoters. The most representative G4-binding ligands have also been documented. The objective of this work is to present a comprehensive overview of the most promising targets for the development of novel and highly specific anticancer drugs capable of selectively impacting the expression of individual or a limited number of genes. EXPERT OPINION Modulation of G4 formation by specific ligands has been proposed as a powerful new tool to treat cancer through the control of oncogene expression. Actually, most of G4-binding small molecules seem to simultaneously target a range of gene promoter G4s, potentially influencing several critical driver genes in cancer, thus producing significant therapeutic benefits.
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Affiliation(s)
- Francesca Romano
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Anna Di Porzio
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Nunzia Iaccarino
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | | | | | - Sonia Laneri
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Bruno Pagano
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Jussara Amato
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Antonio Randazzo
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
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6
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Vianney YM, Schröder N, Jana J, Chojetzki G, Weisz K. Showcasing Different G-Quadruplex Folds of a G-Rich Sequence: Between Rule-Based Prediction and Butterfly Effect. J Am Chem Soc 2023; 145:22194-22205. [PMID: 37751488 DOI: 10.1021/jacs.3c08336] [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: 09/28/2023]
Abstract
In better understanding the interactions of G-quadruplexes in a cellular or noncellular environment, a reliable sequence-based prediction of their three-dimensional fold would be extremely useful, yet is often limited by their remarkable structural diversity. A G-rich sequence related to a promoter sequence of the PDGFR-β nuclease hypersensitivity element (NHE) comprises a G3-G3-G2-G4-G3 pattern of five G-runs with two to four G residues. Although the predominant formation of three-layered canonical G-quadruplexes with uninterrupted G-columns can be expected, minimal base substitutions in a non-G-tract domain were shown to guide folding into either a basket-type antiparallel quadruplex, a parallel-stranded quadruplex with an interrupted G-column, a quadruplex with a V-shaped loop, or a (3+1) hybrid quadruplex. A 3D NMR structure for each of the different folds was determined. Supported by thermodynamic profiling on additional sequence variants, formed topologies were rationalized by the identification and assessment of specific critical interactions of loop and overhang residues, giving valuable insights into their contribution to favor a particular conformer. The variability of such tertiary interactions, together with only small differences in quadruplex free energies, emphasizes current limits for a reliable sequence-dependent prediction of favored topologies from sequences with multiple irregularly positioned G-tracts.
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Affiliation(s)
- Yoanes Maria Vianney
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff Str. 4, D-17489 Greifswald, Germany
| | - Nina Schröder
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff Str. 4, D-17489 Greifswald, Germany
| | - Jagannath Jana
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff Str. 4, D-17489 Greifswald, Germany
| | - Gregor Chojetzki
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff Str. 4, D-17489 Greifswald, Germany
| | - Klaus Weisz
- Institute of Biochemistry, Universität Greifswald, Felix-Hausdorff Str. 4, D-17489 Greifswald, Germany
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7
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Liu Y, Li J, Zhang Y, Wang Y, Chen J, Bian Y, Xia Y, Yang MH, Zheng K, Wang KB, Kong LY. Structure of the Major G-Quadruplex in the Human EGFR Oncogene Promoter Adopts a Unique Folding Topology with a Distinctive Snap-Back Loop. J Am Chem Soc 2023; 145:16228-16237. [PMID: 37460135 DOI: 10.1021/jacs.3c05214] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
EGFR tyrosine kinase inhibitors have made remarkable success in targeted cancer therapy. However, therapeutic resistance inevitably occurred and EGFR-targeting therapy has been demonstrated to have limited efficacy or utility in glioblastoma, colorectal cancer, and hepatocellular carcinoma. Therefore, there is a high demand for the development of new targets to inhibit EGFR signaling. Herein, we found that the EGFR oncogene proximal promoter sequence forms a unique type of snap-back loop containing G-quadruplex (G4), which can be targeted by small molecules. For the first time, we determined the NMR solution structure of this snap-back EGFR-G4, a three-tetrad-core, parallel-stranded G4 with naturally occurring flanking residues at both the 5'-end and 3'-end. The snap-back loop located at the 3'-end region forms a stable capping structure through two stacked G-triads connected by multiple potential hydrogen bonds. Notably, the flanking residues are consistently absent in reported snap-back G4s, raising the question of whether such structures truly exist under in vivo conditions. The resolved EGFR-G4 structure has eliminated the doubt and showed distinct structural features that distinguish it from the previously reported snap-back G4s, which lack the flanking residues. Furthermore, we found that the snap-back EGFR-G4 structure is highly stable and can form on an elongated DNA template to inhibit DNA polymerase. The unprecedented high-resolution EGFR-G4 structure has thus contributed a promising molecular target for developing alternative EGFR signaling inhibitors in cancer therapeutics. Meanwhile, the two stacked triads may provide an attractive site for specific small-molecule targeting.
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Affiliation(s)
- Yushuang Liu
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Jinzhu Li
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Yongqiang Zhang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Yingying Wang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Juannan Chen
- School of Biomedical Sciences, Hunan University, Changsha, Hunan 410082, People's Republic of China
| | - Yuting Bian
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Yuanzheng Xia
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Ming-Hua Yang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Kewei Zheng
- School of Biomedical Sciences, Hunan University, Changsha, Hunan 410082, People's Republic of China
| | - Kai-Bo Wang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
| | - Ling-Yi Kong
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, People's Republic of China
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8
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Falanga AP, Terracciano M, Oliviero G, Roviello GN, Borbone N. Exploring the Relationship between G-Quadruplex Nucleic Acids and Plants: From Plant G-Quadruplex Function to Phytochemical G4 Ligands with Pharmaceutic Potential. Pharmaceutics 2022; 14:2377. [PMID: 36365194 PMCID: PMC9698481 DOI: 10.3390/pharmaceutics14112377] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 10/19/2022] [Accepted: 11/01/2022] [Indexed: 10/31/2023] Open
Abstract
G-quadruplex (G4) oligonucleotides are higher-order DNA and RNA secondary structures of enormous relevance due to their implication in several biological processes and pathological states in different organisms. Strategies aiming at modulating human G4 structures and their interrelated functions are first-line approaches in modern research aiming at finding new potential anticancer treatments or G4-based aptamers for various biomedical and biotechnological applications. Plants offer a cornucopia of phytocompounds that, in many cases, are effective in binding and modulating the thermal stability of G4s and, on the other hand, contain almost unexplored G4 motifs in their genome that could inspire new biotechnological strategies. Herein, we describe some G4 structures found in plants, summarizing the existing knowledge of their functions and biological role. Moreover, we review some of the most promising G4 ligands isolated from vegetal sources and report on the known relationships between such phytochemicals and G4-mediated biological processes that make them potential leads in the pharmaceutical sector.
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Affiliation(s)
- Andrea P. Falanga
- Department of Pharmacy, University of Naples Federico II, Via Domenico Montesano 49, 80131 Naples, Italy
| | - Monica Terracciano
- Department of Pharmacy, University of Naples Federico II, Via Domenico Montesano 49, 80131 Naples, Italy
| | - Giorgia Oliviero
- Department of Molecular Medicine and Medical Biotechnologies, Via Sergio Pansini 5, 80131 Naples, Italy
| | - Giovanni N. Roviello
- Institute of Biostructures and Bioimaging, Italian National Council for Research (IBB-CNR), Area di Ricerca site and Headquarters, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Nicola Borbone
- Department of Pharmacy, University of Naples Federico II, Via Domenico Montesano 49, 80131 Naples, Italy
- Institute of Applied Sciences and Intelligent Systems, Italian National Council of Research (ISASI-CNR), Via Pietro Castellino 111, 80131 Napoli, Italy
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9
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Tong X, Ga L, Eerdun C, Zhao R, Ai J. Simple Monovalent Metal Ion Logical Order to Regulate the Secondary Conformation of G-Quadruplex. ACS OMEGA 2022; 7:39224-39233. [PMID: 36340069 PMCID: PMC9631730 DOI: 10.1021/acsomega.2c05243] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/29/2022] [Indexed: 06/06/2023]
Abstract
Based on the reactions of different sequences with single ions K+, Na, NH4 +, double ions high + low, low + high, and triple ions with different addition orders, the best stable ion combinations of 12 quadruplexes with different DNA sequences were reported. From the fluorescence spectrum, except for HT-V15 and PW17 and AS1411 and HT-V18, the structural stability of G-quadrangle formed basically follows a certain rule. In terms of this experiment, according to circular dichroism, the antiparallel quadrupole structure has the largest proportion among quadrupole structures, and 12 optimal DNA addition schemes and sequences have been obtained through exploration. It is worth mentioning that, on the whole, the best addition scheme of AS1411 and HT-V18 is a three-ion scheme, which provides an effective reference for similar experiments in the future.
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Affiliation(s)
- Xin Tong
- College
of Chemistry and Enviromental Science, Inner Mongolia Key Laboratory
of Environmental Chemistry, Inner Mongolia
Normal University, 81 Zhaowudalu, Hohhot 010022, People’s Republic of China
| | - Lu Ga
- College
of Pharmacy, Inner Mongolia Medical University, Jinchuankaifaqu, Hohhot 010110, People’s Republic of China
| | - Chaolu Eerdun
- College
of Pharmacy, Inner Mongolia Medical University, Jinchuankaifaqu, Hohhot 010110, People’s Republic of China
| | - Ruiguo Zhao
- College
of Chemistry and Chemical Engineering, Inner
Mongolia University, Hohhot 010020, People’s Republic
of China
| | - Jun Ai
- College
of Chemistry and Enviromental Science, Inner Mongolia Key Laboratory
of Environmental Chemistry, Inner Mongolia
Normal University, 81 Zhaowudalu, Hohhot 010022, People’s Republic of China
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10
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Chen L, Dickerhoff J, Sakai S, Yang D. DNA G-Quadruplex in Human Telomeres and Oncogene Promoters: Structures, Functions, and Small Molecule Targeting. Acc Chem Res 2022; 55:2628-2646. [PMID: 36054116 PMCID: PMC9937053 DOI: 10.1021/acs.accounts.2c00337] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
DNA G-quadruplex secondary structures formed in guanine-rich human telomeres and oncogene promoters are functionally important and have emerged as a promising new class of cancer-specific drug targets. These globular intramolecular structures are stabilized by K+ or Na+ and form readily under physiological solution conditions. Moreover, G-quadruplexes are epigenetic features and can alter chromatin structure and function together with interactive proteins. Here, we discuss our efforts over the last two decades to understand the structures and functions of DNA G-quadruplexes formed in key oncogene promoters and human telomeres and their interactions with small molecules. Using high-field NMR spectroscopy, we determined the high-resolution structures of physiologically relevant telomeric G-quadruplexes in K+ solution with a major form (hybrid-2) and a minor form (hybrid-1), as well as a two-tetrad intermediate. The intrinsic structural polymorphism of telomeric DNA may be important for the biology of human telomeres, and we proposed a model for the interconversion. More recently, we have worked on G-quadruplexes of MYC, BCL2, PDGFR-β, VEGF, and k-RAS oncogene promoters. We determined the structure of the major G-quadruplex formed in the MYC promoter, a prototype for parallel G-quadruplexes. It is the first example of the parallel-stranded G3NG3 structure motif with a 1-nt loop, which is prevalent in promoter sequences and likely evolutionarily selected to initiate folding. Remarkably, the parallel MYC promoter G-quadruplexes are highly stable. Additionally, we determined the molecular structures of G-quadruplexes formed in human BCL2, VEGF, and PDGFR-β promoters, each adopting a unique structure. For example, the BCL2 promoter contains distinct interchangeable G-quadruplexes in two adjacent regions, suggesting precise regulation by different proteins. The PDGFR-β promoter adopts unique "broken-strand" and vacancy G-quadruplexes, which can be recognized by cellular guanine metabolites for a potential regulatory role.Structural information on G-quadruplexes in complex with small-molecules is critical for understanding specific recognition and structure-based rational drug design. Our studies show that many G-quadruplexes contain unique structural features such as capping and loop structures, allowing specific recognition by drugs and protein. This represents a paradigm shift in understanding DNA as a drug target: Rather than a uniform, nonselective binding site in duplex DNA, the G-quadruplex is being pursued as a new class of selectively targetable drug receptors. We focus on targeting the biologically relevant MYC promoter G-quadruplex (MycG4) with small molecules and have determined its first and additional drug complex structures. Very recently, we have discovered clinically tested indenoisoquinolines as strong MycG4 binders and potent MYC inhibitors. We have also discovered drugs targeting the unique dGMP-bound-vG4 formed in the PDGFR-β promoter. Moreover, we determined the complex structures of the first small molecules that specifically recognize the physiologically relevant human telomeric G-quadruplexes. Unlike the previously recognized dogma that the optimal G-quadruplex ligands are large aromatic or cyclic compounds, our results suggest that smaller asymmetric compounds with appropriate functional groups are better choices to specifically bind G-quadruplexes. This body of work lays a strong foundation for future work aimed at understanding the cellular functions of G-quadruplexes and G-quadruplex-targeted drug design.
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Affiliation(s)
- Luying Chen
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Jonathan Dickerhoff
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Saburo Sakai
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
- Biogeochemistry Research Center, Japan Agency for Marine-Earth Science and Technology, 2-15, Natsushima-cho, Yokosuka-city, Kanagawa 237-0061, Japan
| | - Danzhou Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
- Purdue Center for Cancer Research, Purdue University, 201 University Street, West Lafayette, Indiana 47907, United States
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
- Purdue Institute for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, Indiana 47907, United States
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11
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Chang T, Li G, Ding Z, Li W, Zhu P, Lei W, Shangguan D. Potential G-quadruplexes within the Promoter Nuclease Hypersensitive Sites of the Heat-responsive Genes in Rice. Chembiochem 2022; 23:e202200405. [PMID: 36006168 DOI: 10.1002/cbic.202200405] [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: 07/18/2022] [Revised: 08/21/2022] [Indexed: 11/11/2022]
Abstract
G-quadruplexes (G4s) have been shown to be involved in the regulation of multiple cellular processes. Exploring putative G4-forming sequences (PQSs) in heat-responsive genes of rice and their folding structures under different conditions will help to understand the mechanism in response to heat stress. In this work, we discovered a prevalence of PQSs in nuclease hypersensitive sites within the promoters of heat-responsive genes. Moreover, 50% of the searched G3 PQSs ((G3+L1-7)3+G3+) locate in heat shock transcription factors. Circular dichroism spectroscopy, thermal difference spectroscopy, and UV melting analysis demonstrated the representative PQSs could adopt stable G4s at physiological temperature and potassium concentration. These PQSs were able to stall Klenow Fragment (KF) DNA polymerase by the formation of G4s. However, the G4s with Tm values around 50 - 60 oC could be increasingly unwound by KF with the increase of temperatures from 25 to 50 oC, implying these G4s could sense the changes in temperature by structural switch. This work offers fresh clue to understand the potential of G4-involved functions of PQSs and the molecular events in plants in the response to heat stress.
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Affiliation(s)
- Tianjun Chang
- Henan Polytechnic University, Institute of Enveiroment and Resoures, 2001 Shiji Avenue, 454003, Jiaozuo, CHINA
| | - Guangping Li
- Henan Polytechnic University, Institute of Resources and Environment, CHINA
| | - Zhan Ding
- Henan Polytechnic University, Institute of Resources and Environment, CHINA
| | - Weiguo Li
- Henan Polytechnic University, Institute of Resources and Environment, CHINA
| | - Panpan Zhu
- Henan Polytechnic University, Institute of Resources and Environment, CHINA
| | - Wei Lei
- Henan Polytechnic University, Institute of Resources and Environment, CHINA
| | - Dihua Shangguan
- Institute of Chemistry Chinese Academy of Sciences, Beijing National Laboratory for Molecular Sciences, Key Labor-atory of Analytical Chemistry for Living Biosystems, CAS Re-search/Education Center for Excellence in Molecular Sciences, CHINA
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12
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Jana J, Vianney YM, Schröder N, Weisz K. Guiding the folding of G-quadruplexes through loop residue interactions. Nucleic Acids Res 2022; 50:7161-7175. [PMID: 35758626 PMCID: PMC9262619 DOI: 10.1093/nar/gkac549] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/25/2022] [Accepted: 06/14/2022] [Indexed: 12/24/2022] Open
Abstract
A G-rich sequence was designed to allow folding into either a stable parallel or hybrid-type topology. With the parent sequence featuring coexisting species, various related sequences with single and double mutations and with a shortened central propeller loop affected the topological equilibrium. Two simple modifications, likewise introduced separately to all sequences, were employed to lock folds into one of the topologies without noticeable structural alterations. The unique combination of sequence mutations, high-resolution NMR structural information, and the thermodynamic stability for both topological competitors identified critical loop residue interactions. In contrast to first loop residues, which are mostly disordered and exposed to solvent in both propeller and lateral loops bridging a narrow groove, the last loop residue in a lateral three-nucleotide loop is engaged in stabilizing stacking interactions. The propensity of single-nucleotide loops to favor all-parallel topologies by enforcing a propeller-like conformation of an additional longer loop is shown to result from their preference in linking two outer tetrads of the same tetrad polarity. Taken together, the present studies contribute to a better structural and thermodynamic understanding of delicate loop interactions in genomic and artificially designed quadruplexes, e.g. when employed as therapeutics or in other biotechnological applications.
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Affiliation(s)
- Jagannath Jana
- Institute of Biochemistry, Universität Greifswald, D-17489 Greifswald, Germany
| | | | - Nina Schröder
- Institute of Biochemistry, Universität Greifswald, D-17489 Greifswald, Germany
| | - Klaus Weisz
- To whom correspondence should be addressed. Tel: +49 3834 420 4426; Fax: +49 3834 420 4427;
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13
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Exploring the Parallel G-Quadruplex Nucleic Acid World: A Spectroscopic and Computational Investigation on the Binding of the c-myc Oncogene NHE III1 Region by the Phytochemical Polydatin. Molecules 2022; 27:molecules27092997. [PMID: 35566347 PMCID: PMC9099682 DOI: 10.3390/molecules27092997] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/04/2022] [Accepted: 05/05/2022] [Indexed: 02/04/2023] Open
Abstract
Trans-polydatin (tPD), the 3-β-D-glucoside of the well-known nutraceutical trans-resveratrol, is a natural polyphenol with documented anti-cancer, anti-inflammatory, cardioprotective, and immunoregulatory effects. Considering the anticancer activity of tPD, in this work, we aimed to explore the binding properties of this natural compound with the G-quadruplex (G4) structure formed by the Pu22 [d(TGAGGGTGGGTAGGGTGGGTAA)] DNA sequence by exploiting CD spectroscopy and molecular docking simulations. Pu22 is a mutated and shorter analog of the G4-forming sequence known as Pu27 located in the promoter of the c-myc oncogene, whose overexpression triggers the metabolic changes responsible for cancer cells transformation. The binding of tPD with the parallel Pu22 G4 was confirmed by CD spectroscopy, which showed significant changes in the CD spectrum of the DNA and a slight thermal stabilization of the G4 structure. To gain a deeper insight into the structural features of the tPD-Pu22 complex, we performed an in silico molecular docking study, which indicated that the interaction of tPD with Pu22 G4 may involve partial end-stacking to the terminal G-quartet and H-bonding interactions between the sugar moiety of the ligand and deoxynucleotides not included in the G-tetrads. Finally, we compared the experimental CD profiles of Pu22 G4 with the corresponding theoretical output obtained using DichroCalc, a web-based server normally used for the prediction of proteins’ CD spectra starting from their “.pdb” file. The results indicated a good agreement between the predicted and the experimental CD spectra in terms of the spectral bands’ profile even if with a slight bathochromic shift in the positive band, suggesting the utility of this predictive tool for G4 DNA CD investigations.
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14
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Tong X, Ga L, Ai J, Wang Y. Progress in cancer drug delivery based on AS1411 oriented nanomaterials. J Nanobiotechnology 2022; 20:57. [PMID: 35101048 PMCID: PMC8805415 DOI: 10.1186/s12951-022-01240-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 01/02/2022] [Indexed: 02/07/2023] Open
Abstract
Targeted cancer therapy has become one of the most important medical methods because of the spreading and metastatic nature of cancer. Based on the introduction of AS1411 and its four-chain structure, this paper reviews the research progress in cancer detection and drug delivery systems by modifying AS1411 aptamers based on graphene, mesoporous silica, silver and gold. The application of AS1411 in cancer treatment and drug delivery and the use of AS1411 as a targeting agent for the detection of cancer markers such as nucleoli were summarized from three aspects of active targeting, passive targeting and targeted nucleic acid apharmers. Although AS1411 has been withdrawn from clinical trials, the research surrounding its structural optimization is still very popular. Further progress has been made in the modification of nanoparticles loaded with TCM extracts by AS1411.
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Affiliation(s)
- Xin Tong
- College of Chemistry and Environmental Science, College of Geographical Science, Inner Mongolia Key Laboratory of Environmental Chemistry, Inner Mongolia Normal University, 81 Zhaowudalu, Hohhot, 010022, China
| | - Lu Ga
- College of Pharmacy, Inner Mongolia Medical University, Jinchuankaifaqu, Hohhot, 010110, China
| | - Jun Ai
- College of Chemistry and Environmental Science, College of Geographical Science, Inner Mongolia Key Laboratory of Environmental Chemistry, Inner Mongolia Normal University, 81 Zhaowudalu, Hohhot, 010022, China.
| | - Yong Wang
- College of Chemistry and Environmental Science, College of Geographical Science, Inner Mongolia Key Laboratory of Environmental Chemistry, Inner Mongolia Normal University, 81 Zhaowudalu, Hohhot, 010022, China.
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15
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Chen JN, He YD, Liang HT, Cai TT, Chen Q, Zheng KW. Regulation of PDGFR-β gene expression by targeting the G-vacancy bearing G-quadruplex in promoter. Nucleic Acids Res 2021; 49:12634-12643. [PMID: 34850916 PMCID: PMC8682790 DOI: 10.1093/nar/gkab1154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/14/2021] [Accepted: 11/09/2021] [Indexed: 12/31/2022] Open
Abstract
G-quadruplex is an essential element in gene transcription that serves as a promising drug target. Guanine-vacancy-bearing G-quadruplex (GVBQ) is a newly identified G-quadruplex that has distinct structural features from the canonical G-quadruplex. Potential GVBQ-forming motifs are widely distributed in gene promoter regions. However, whether GVBQ can form in genomic DNA and be an effective target for manipulating gene expression is unknown. Using photo-crosslinking, dimethyl sulfate footprinting, exonuclease digestion and in vitro transcription, we demonstrated the formation of a GVBQ in the G-rich nuclease hypersensitivity element within the human PDGFR-β gene promoter region in both single-stranded and double-stranded DNA. The formation of GVBQ in dsDNA could be induced by negative supercoiling created by downstream transcription. We also found that the PDGFR-β GVBQ was specifically recognized and stabilized by a new synthetic porphyrin guanine conjugate (mPG). Targeting the PDGFR-β GVBQ in human cancer cells using the mPG could specifically alter PDGFR-β gene expression. Our work illustrates that targeting GVBQ with mPG in human cells can regulate the expression level of a specific gene, thus indicating a novel strategy for drug development.
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Affiliation(s)
- Juan-Nan Chen
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-Sen University, Guangzhou 510006, P.R. China
| | - Yi-de He
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-Sen University, Guangzhou 510006, P.R. China.,School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, P.R. China
| | - Hui-Ting Liang
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-Sen University, Guangzhou 510006, P.R. China
| | - Ting-Ting Cai
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-Sen University, Guangzhou 510006, P.R. China
| | - Qi Chen
- School of Public Health (Shenzhen), Sun Yat-Sen University, Guangzhou 510006, P.R. China
| | - Ke-Wei Zheng
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-Sen University, Guangzhou 510006, P.R. China
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16
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Grün JT, Schwalbe H. Folding dynamics of polymorphic G-quadruplex structures. Biopolymers 2021; 113:e23477. [PMID: 34664713 DOI: 10.1002/bip.23477] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/30/2021] [Accepted: 09/30/2021] [Indexed: 12/14/2022]
Abstract
G-quadruplexes (G4), found in numerous places within the human genome, are involved in essential processes of cell regulation. Chromosomal DNA G4s are involved for example, in replication and transcription as first steps of gene expression. Hence, they influence a plethora of downstream processes. G4s possess an intricate structure that differs from canonical B-form DNA. Identical DNA G4 sequences can adopt multiple long-lived conformations, a phenomenon known as G4 polymorphism. A detailed understanding of the molecular mechanisms that drive G4 folding is essential to understand their ambivalent regulatory roles. Disentangling the inherent dynamic and polymorphic nature of G4 structures thus is key to unravel their biological functions and make them amenable as molecular targets in novel therapeutic approaches. We here review recent experimental approaches to monitor G4 folding and discuss structural aspects for possible folding pathways. Substantial progress in the understanding of G4 folding within the recent years now allows drawing comprehensive models of the complex folding energy landscape of G4s that we herein evaluate based on computational and experimental evidence.
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Affiliation(s)
- J Tassilo Grün
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Johann Wolfgang Goethe-University, Frankfurt/M, Germany.,Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Frankfurt/M, Germany
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17
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Wang KB, Dickerhoff J, Yang D. Solution Structure of Ternary Complex of Berberine Bound to a dGMP-Fill-In Vacancy G-Quadruplex Formed in the PDGFR-β Promoter. J Am Chem Soc 2021; 143:16549-16555. [PMID: 34586799 PMCID: PMC8626096 DOI: 10.1021/jacs.1c06200] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The G-quadruplexes (G4s) formed in the PDGFR-β gene promoter are transcriptional modulators and amenable to small-molecule targeting. Berberine (BER), a clinically important natural isoquinoline alkaloid, has gained increasing attention due to its potential as anticancer drug. We previously showed that the PDGFR-β gene promoter forms a unique vacancy G4 (vG4) that can be filled in and stabilized by guanine metabolites, such as dGMP. Herein, we report the high-resolution NMR structure of a ternary complex of berberine bound to the dGMP-fill-in PDGFR-β vG4 in potassium solution. This is the first small-molecule complex structure of a fill-in vG4. This ternary complex has a 2:1:1 binding stoichiometry with a berberine molecule bound at each the 5'- and 3'-end of the 5'-dGMP-fill-in PDGFR-β vG4. Each berberine recruits the adjacent adenine residue from the 5'- or 3'-flanking sequence to form a "quasi-triad plane" that covers the external G-tetrad of the fill-in vG4, respectively. Significantly, berberine covers and stabilizes the fill-in dGMP. The binding of berberine involves both π-stacking and electrostatic interactions, and the fill-in dGMP is covered and well-protected by berberine. The NMR structure can guide rational design of berberine analogues that target the PDGFR-β vG4 or dGMP-fill-in vG4. Moreover, our structure provides a molecular basis for designing small-molecule guanine conjugates to target vG4s.
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18
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Pandya N, Jain N, Kumar A. Interaction analysis of anti-cancer drug Methotrexate with bcl-2 promoter stabilization and its transcription regulation. GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2021.101155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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19
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Jana J, Mohr S, Vianney YM, Weisz K. Structural motifs and intramolecular interactions in non-canonical G-quadruplexes. RSC Chem Biol 2021; 2:338-353. [PMID: 34458788 PMCID: PMC8341446 DOI: 10.1039/d0cb00211a] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/14/2021] [Indexed: 12/12/2022] Open
Abstract
Guanine(G)-rich DNA or RNA sequences can assemble or intramolecularly fold into G-quadruplexes formed through the stacking of planar G·G·G·G tetrads in the presence of monovalent cations. These secondary nucleic acid structures have convincingly been shown to also exist within a cellular environment exerting important regulatory functions in physiological processes. For identifying nucleic acid segments prone to quadruplex formation, a putative quadruplex sequence motif encompassing closely spaced tracts of three or more guanosines is frequently employed for bioinformatic search algorithms. Depending on the number and type of intervening residues as well as on solution conditions, such sequences may fold into various canonical G4 topologies with continuous G-columns. On the other hand, a growing number of sequences capable of quadruplex formation feature G-deficient guanine tracts, escaping the conservative consensus motif. By folding into non-canonical quadruplex structures, they adopt unique topologies depending on their specific sequence context. These include G-columns with only two guanines, bulges, snapback loops, D- and V-shaped loops as well as interlocked structures. This review focuses on G-quadruplex species carrying such distinct structural motifs. It evaluates characteristic features of their non-conventional scaffold and highlights principles of stabilizing interactions that also allow for their folding into stable G-quadruplex structures.
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Affiliation(s)
- Jagannath Jana
- Institute of Biochemistry, Universität Greifswald Felix-Hausdorff-Str. 4 D-17487 Greifswald Germany +49 3834 420-4427 +49 3834 420-4426
| | - Swantje Mohr
- Institute of Biochemistry, Universität Greifswald Felix-Hausdorff-Str. 4 D-17487 Greifswald Germany +49 3834 420-4427 +49 3834 420-4426
| | - Yoanes Maria Vianney
- Institute of Biochemistry, Universität Greifswald Felix-Hausdorff-Str. 4 D-17487 Greifswald Germany +49 3834 420-4427 +49 3834 420-4426
| | - Klaus Weisz
- Institute of Biochemistry, Universität Greifswald Felix-Hausdorff-Str. 4 D-17487 Greifswald Germany +49 3834 420-4427 +49 3834 420-4426
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20
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Jing H, Fu W, Hu W, Xu S, Xu X, He M, Liu Y, Zhang N. NMR structural study on the self-trimerization of d(GTTAGG) into a dynamic trimolecular G-quadruplex assembly preferentially in Na+ solution with a moderate K+ tolerance. Nucleic Acids Res 2021; 49:2306-2316. [PMID: 33524157 PMCID: PMC7913680 DOI: 10.1093/nar/gkab028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/05/2021] [Accepted: 01/15/2021] [Indexed: 12/12/2022] Open
Abstract
Vast G-quadruplexes (GQs) are primarily folded by one, two, or four G-rich oligomers, rarely with an exception. Here, we present the first NMR solution structure of a trimolecular GQ (tri-GQ) that is solely assembled by the self-trimerization of d(GTTAGG), preferentially in Na+ solution tolerant to an equal amount of K+ cation. Eight guanines from three asymmetrically folded strands of d(GTTAGG) are organized into a two-tetrad core, which features a broken G-column and two width-irregular grooves. Fast strand exchanges on a timescale of second at 17°C spontaneously occur between folded tri-GQ and unfolded single-strand of d(GTTAGG) that both species coexist in dynamic equilibrium. Thus, this tri-GQ is not just simply a static assembly but rather a dynamic assembly. Moreover, another minor tetra-GQ that has putatively tetrameric (2+2) antiparallel topology becomes noticeable only at an extremely high strand concentration above 18 mM. The major tri-GQ and minor tetra-GQ are considered to be mutually related, and their reversible interconversion pathways are proposed accordingly. The sequence d(GTTAGG) could be regarded as either a reading frame shifted single repeat of human telomeric DNA or a 1.5 repeat of Bombyx mori telomeric DNA. Overall, our findings provide new insight into GQs and expect more functional applications.
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Affiliation(s)
- Haitao Jing
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.,University of Science and Technology of China, Hefei 230026, China
| | - Wenqiang Fu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.,University of Science and Technology of China, Hefei 230026, China
| | - Wenxuan Hu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.,University of Science and Technology of China, Hefei 230026, China
| | - Suping Xu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China
| | - Xiaojuan Xu
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.,University of Science and Technology of China, Hefei 230026, China
| | - Miao He
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.,University of Science and Technology of China, Hefei 230026, China
| | - Yangzhong Liu
- University of Science and Technology of China, Hefei 230026, China
| | - Na Zhang
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China.,Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China.,Key Laboratory of Anhui Province for High Field Magnetic Resonance Imaging, Hefei 230031, China.,High Magnetic Field Laboratory of Anhui Province, Hefei 230031, China
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21
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Sanchez-Martin V, Lopez-Pujante C, Soriano-Rodriguez M, Garcia-Salcedo JA. An Updated Focus on Quadruplex Structures as Potential Therapeutic Targets in Cancer. Int J Mol Sci 2020; 21:ijms21238900. [PMID: 33255335 PMCID: PMC7734589 DOI: 10.3390/ijms21238900] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/13/2020] [Accepted: 11/20/2020] [Indexed: 02/06/2023] Open
Abstract
Non-canonical, four-stranded nucleic acids secondary structures are present within regulatory regions in the human genome and transcriptome. To date, these quadruplex structures include both DNA and RNA G-quadruplexes, formed in guanine-rich sequences, and i-Motifs, found in cytosine-rich sequences, as their counterparts. Quadruplexes have been extensively associated with cancer, playing an important role in telomere maintenance and control of genetic expression of several oncogenes and tumor suppressors. Therefore, quadruplex structures are considered attractive molecular targets for cancer therapeutics with novel mechanisms of action. In this review, we provide a general overview about recent research on the implications of quadruplex structures in cancer, firstly gathering together DNA G-quadruplexes, RNA G-quadruplexes as well as DNA i-Motifs.
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Affiliation(s)
- Victoria Sanchez-Martin
- GENYO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, 18016 Granada, Spain; (V.S.-M.); (C.L.-P.)
- Microbiology Unit, University Hospital Virgen de las Nieves, Biosanitary Research Institute IBS, Granada, 18014 Granada, Spain
- Department of Biochemistry, Molecular Biology III and Immunology, University of Granada, 18016 Granada, Spain
| | - Carmen Lopez-Pujante
- GENYO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, 18016 Granada, Spain; (V.S.-M.); (C.L.-P.)
| | - Miguel Soriano-Rodriguez
- GENYO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, 18016 Granada, Spain; (V.S.-M.); (C.L.-P.)
- Centre for Intensive Mediterranean Agrosystems and Agri-food Biotechnology (CIAMBITAL), University of Almeria, 04001 Almeria, Spain
- Correspondence: (M.S.-R.); (J.A.G.-S.); Tel.: +34-958715500 (M.S.-R.); +34-958715500 (J.A.G.-S.)
| | - Jose A. Garcia-Salcedo
- GENYO, Centre for Genomics and Oncological Research, Pfizer/University of Granada/Andalusian Regional Government, PTS Granada, 18016 Granada, Spain; (V.S.-M.); (C.L.-P.)
- Microbiology Unit, University Hospital Virgen de las Nieves, Biosanitary Research Institute IBS, Granada, 18014 Granada, Spain
- Correspondence: (M.S.-R.); (J.A.G.-S.); Tel.: +34-958715500 (M.S.-R.); +34-958715500 (J.A.G.-S.)
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22
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Custom G4 Microarrays Reveal Selective G-Quadruplex Recognition of Small Molecule BMVC: A Large-Scale Assessment of Ligand Binding Selectivity. Molecules 2020; 25:molecules25153465. [PMID: 32751510 PMCID: PMC7436161 DOI: 10.3390/molecules25153465] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 07/24/2020] [Accepted: 07/25/2020] [Indexed: 11/17/2022] Open
Abstract
G-quadruplexes (G4) are considered new drug targets for human diseases such as cancer. More than 10,000 G4s have been discovered in human chromatin, posing challenges for assessing the selectivity of a G4-interactive ligand. 3,6-bis(1-Methyl-4-vinylpyridinium) carbazole diiodide (BMVC) is the first fluorescent small molecule for G4 detection in vivo. Our previous structural study shows that BMVC binds to the MYC promoter G4 (MycG4) with high specificity. Here, we utilize high-throughput, large-scale custom DNA G4 microarrays to analyze the G4-binding selectivity of BMVC. BMVC preferentially binds to the parallel MycG4 and selectively recognizes flanking sequences of parallel G4s, especially the 3′-flanking thymine. Importantly, the microarray results are confirmed by orthogonal NMR and fluorescence binding analyses. Our study demonstrates the potential of custom G4 microarrays as a platform to broadly and unbiasedly assess the binding selectivity of G4-interactive ligands, and to help understand the properties that govern molecular recognition.
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23
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Cao Y, Li W, Gao T, Ding P, Pei R. One Terminal Guanosine Flip of Intramolecular Parallel G-Quadruplex: Catalytic Enhancement of G-Quadruplex/Hemin DNAzymes. Chemistry 2020; 26:8631-8638. [PMID: 32428287 DOI: 10.1002/chem.202001462] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/13/2020] [Indexed: 11/09/2022]
Abstract
Numerous studies have shown compelling evidence that incorporation of an inversion of polarity site (IPS) in G-rich sequences can affect the topological and structural characteristics of G-quadruplexes (G4s). Herein, the influence of IPS on the formation of a previously studied intramolecular parallel G4 of d(G3 TG3 TG3 TG3 ) (TTT) and its stacked higher-order structures is explored. Insertion of 3'-3' or 5'-5' IPS did not change the parallel folding pattern of TTT. However, both the species and position of the IPS in TTT have a significant impact on the G4 stability and end-stacking through the alteration of G4-G4 interfaces properties. The data demonstrate that one base flip in each terminal G-tetrad can stabilize parallel G4s and facilitate intermolecular packing of monomeric G4s. Such modifications can also enhance the fluorescence and enzymatic performances by promoting interactions between parallel G4s with N-methyl mesoporphyrin IX (NMM) and hemin, respectively.
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Affiliation(s)
- Yanwei Cao
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionic, Chinese Academy of Sciences, Suzhou, 215123, P. R. China
| | - Wenjing Li
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionic, Chinese Academy of Sciences, Suzhou, 215123, P. R. China
| | - Tian Gao
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionic, Chinese Academy of Sciences, Suzhou, 215123, P. R. China
| | - Pi Ding
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionic, Chinese Academy of Sciences, Suzhou, 215123, P. R. China
| | - Renjun Pei
- CAS Key Laboratory of Nano-Bio Interface, Division of Nanobiomedicine, Suzhou Institute of Nano-Tech and Nano-Bionic, Chinese Academy of Sciences, Suzhou, 215123, P. R. China
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24
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Wang KB, Dickerhoff J, Wu G, Yang D. PDGFR-β Promoter Forms a Vacancy G-Quadruplex that Can Be Filled in by dGMP: Solution Structure and Molecular Recognition of Guanine Metabolites and Drugs. J Am Chem Soc 2020; 142:5204-5211. [PMID: 32101424 DOI: 10.1021/jacs.9b12770] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Aberrant expression of PDGFR-β is associated with a number of diseases. The G-quadruplexes (G4s) formed in PDGFR-β gene promoter are transcriptional modulators and amenable to small molecule targeting. The major G4 formed in the PDGFR-β gene promoter was previously shown to have a broken G-strand. Herein, we report that the PDGFR-β gene promoter sequence forms a vacancy G-quadruplex (vG4) which can be filled in and stabilized by physiologically relevant guanine metabolites, such as dGMP, GMP, and cGMP, as well as guanine-derivative drugs. We determined the NMR structure of the dGMP-fill-in PDGFR-β vG4 in K+ solution. This is the first structure of a guanine-metabolite-fill-in vG4 based on a human gene promoter sequence. Our structure and systematic analysis elucidate the contributions of Hoogsten hydrogen bonds, sugar, and phosphate moieties to the specific G-vacancy fill-in. Intriguingly, an equilibrium of 3'- and 5'-end vG4s is present in the PDGFR-β promoter sequence, and dGMP favors the 5'-end fill-in. Guanine metabolites and drugs were tested and showed a conserved selectivity for the 5'-vacancy, except for cGMP. cGMP binds both the 3'- and 5'-end vG4s and forms two fill-in G4s with similar population. Significantly, guanine metabolites are involved in many physiological and pathological processes in human cells; thus, our results provide a structural basis to understand their potential regulatory functions by interaction with promoter vG4s. Moreover, the NMR structure can guide rational design of ligands that target the PDGFR-β vG4.
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25
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Takahashi S, Sugimoto N. Stability prediction of canonical and non-canonical structures of nucleic acids in various molecular environments and cells. Chem Soc Rev 2020; 49:8439-8468. [DOI: 10.1039/d0cs00594k] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review provides the biophysicochemical background and recent advances in stability prediction of canonical and non-canonical structures of nucleic acids in various molecular environments and cells.
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Affiliation(s)
- Shuntaro Takahashi
- Frontier Institute for Biomolecular Engineering Research (FIBER)
- Konan University
- Kobe
- Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER)
- Konan University
- Kobe
- Japan
- Graduate School of Frontiers of Innovative Research in Science and Technology (FIRST)
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26
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Oxidative Stress: Role and Response of Short Guanine Tracts at Genomic Locations. Int J Mol Sci 2019; 20:ijms20174258. [PMID: 31480304 PMCID: PMC6747389 DOI: 10.3390/ijms20174258] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/20/2019] [Accepted: 07/26/2019] [Indexed: 12/21/2022] Open
Abstract
Over the decades, oxidative stress has emerged as a major concern to biological researchers. It is involved in the pathogenesis of various lifestyle-related diseases such as hypertension, diabetes, atherosclerosis, and neurodegenerative diseases. The connection between oxidative stress and telomere shortening via oxidative guanine lesion is well documented. Telomeres are confined to guanine rich ends of chromosomes. Owing to its self-association properties, it adopts G-quadruplex structures and hampers the overexpression of telomerase in the cancer cells. Guanine, being the most oxidation prone nucleobase, when structured in G-quadruplex entity, is found to respond peculiarly towards oxidative stress. Interestingly, this non-Watson-Crick structural feature exists abundantly in promoters of various oncogenes, exons and other genomic locations. The involvement of G-quadruplex architecture in oncogene promoters is well recognized in gene regulation processes. Development of small molecules aimed to target G-quadruplex structures, have found to alter the overexpression of oncogenes. The interaction may lead to the obstruction of diseased cell having elevated level of reactive oxygen species (ROS). Thus, presence of short guanine tracts (Gn) forming G-quadruplexes suggests its critical role in oxidative genome damage. Present review is a modest attempt to gain insight on the association of oxidative stress and G-quadruplexes, in various biological processes.
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27
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Lightfoot HL, Hagen T, Tatum NJ, Hall J. The diverse structural landscape of quadruplexes. FEBS Lett 2019; 593:2083-2102. [PMID: 31325371 DOI: 10.1002/1873-3468.13547] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 07/09/2019] [Accepted: 07/15/2019] [Indexed: 12/15/2022]
Abstract
G-quadruplexes are secondary structures formed in G-rich sequences in DNA and RNA. Considerable research over the past three decades has led to in-depth insight into these unusual structures in DNA. Since the more recent exploration into RNA G-quadruplexes, such structures have demonstrated their in cellulo existence, function and roles in pathology. In comparison to Watson-Crick-based secondary structures, most G-quadruplexes display highly redundant structural characteristics. However, numerous reports of G-quadruplex motifs/structures with unique features (e.g. bulges, long loops, vacancy) have recently surfaced, expanding the repertoire of G-quadruplex scaffolds. This review addresses G-quadruplex formation and structure, including recent reports of non-canonical G-quadruplex structures. Improved methods of detection will likely further expand this collection of novel structures and ultimately change the face of quadruplex-RNA targeting as a therapeutic strategy.
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Affiliation(s)
- Helen L Lightfoot
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| | - Timo Hagen
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
| | - Natalie J Tatum
- Newcastle Cancer Centre, Northern Institute for Cancer Research, Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Jonathan Hall
- Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, ETH Zurich, Switzerland
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28
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Developing Novel G-Quadruplex Ligands: from Interaction with Nucleic Acids to Interfering with Nucleic Acid⁻Protein Interaction. Molecules 2019; 24:molecules24030396. [PMID: 30678288 PMCID: PMC6384609 DOI: 10.3390/molecules24030396] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/10/2019] [Accepted: 01/22/2019] [Indexed: 12/20/2022] Open
Abstract
G-quadruplex is a special secondary structure of nucleic acids in guanine-rich sequences of genome. G-quadruplexes have been proved to be involved in the regulation of replication, DNA damage repair, and transcription and translation of oncogenes or other cancer-related genes. Therefore, targeting G-quadruplexes has become a novel promising anti-tumor strategy. Different kinds of small molecules targeting the G-quadruplexes have been designed, synthesized, and identified as potential anti-tumor agents, including molecules directly bind to the G-quadruplex and molecules interfering with the binding between the G-quadruplex structures and related binding proteins. This review will explore the feasibility of G-quadruplex ligands acting as anti-tumor drugs, from basis to application. Meanwhile, since helicase is the most well-defined G-quadruplex-related protein, the most extensive research on the relationship between helicase and G-quadruplexes, and its meaning in drug design, is emphasized.
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29
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Abstract
G-quadruplexes (G4s) have become one of the most exciting nucleic acid secondary structures. A noncanonical, four-stranded structure formed in guanine-rich DNA and RNA sequences, G-quadruplexes can readily form under physiologically relevant conditions and are globularly folded structures. DNA is widely recognized as a double-helical structure essential in genetic information storage. However, only ~3% of the human genome is expressed in protein; RNA and DNA may form noncanonical secondary structures that are functionally important. G-quadruplexes are one such example which have gained considerable attention for their formation and regulatory roles in biologically significant regions, such as human telomeres, oncogene-promoter regions, replication initiation sites, and 5'- and 3'-untranslated region (UTR) of mRNA. They are shown to be a regulatory motif in a number of critical cellular processes including gene transcription, translation, replication, and genomic stability. G-quadruplexes are also found in nonhuman genomes, particularly those of human pathogens. Therefore, G-quadruplexes have emerged as a new class of molecular targets for drug development. In addition, there is considerable interest in the use of G-quadruplexes for biomaterials, biosensors, and biocatalysts. The First International Meeting on Quadruplex DNA was held in 2007, and the G-quadruplex field has been growing dramatically over the last decade. The methods used to study G-quadruplexes have been essential to the rapid progress in our understanding of this exciting nucleic acid secondary structure.
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Affiliation(s)
- Danzhou Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, Purdue Center for Cancer Research, Purdue Institute for Drug Discovery, West Lafayette, IN USA
| | - Clement Lin
- Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, IN USA
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30
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Whole-Transcriptome Profiling of Canine and Human in Vitro Models Exposed to a G-Quadruplex Binding Small Molecule. Sci Rep 2018; 8:17107. [PMID: 30459395 PMCID: PMC6244004 DOI: 10.1038/s41598-018-35516-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 11/06/2018] [Indexed: 11/24/2022] Open
Abstract
G-quadruplexes (G4) are secondary nucleic acid structures that have been associated with genomic instability and cancer progression. When present in the promoter of some oncogenes, G4 structures can affect gene regulation and, hence, represent a possible therapeutic target. In this study, RNA-Seq was used to explore the effect of a G4-binding anthraquinone derivative, named AQ1, on the whole-transcriptome profiles of two common cell models for the study of KIT pathways; the human mast cell leukemia (HMC1.2) and the canine mast cell tumor (C2). The highest non-cytotoxic dose of AQ1 (2 µM) resulted in 5441 and 1201 differentially expressed genes in the HMC1.2 and C2 cells, respectively. In both cell lines, major pathways such as cell cycle progression, KIT- and MYC-related pathways were negatively enriched in the AQ1-treated group, while other pathways such as p53, apoptosis and hypoxia-related were positively enriched. These findings suggest that AQ1 treatment induces a similar functional response in the human and canine cell models, and provide news insights into using dogs as a reliable translational model for studying G4-binding compounds.
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31
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Manna S, Srivatsan SG. Fluorescence-based tools to probe G-quadruplexes in cell-free and cellular environments. RSC Adv 2018; 8:25673-25694. [PMID: 30210793 PMCID: PMC6130854 DOI: 10.1039/c8ra03708f] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/08/2018] [Indexed: 12/26/2022] Open
Abstract
Biophysical and biochemical investigations provide compelling evidence connecting the four-stranded G-quadruplex (GQ) structure with its role in regulating multiple cellular processes. Hence, modulating the function of GQs by using small molecule binders is being actively pursued as a strategy to develop new chemotherapeutic agents. However, sequence diversity and structural polymorphism of GQs have posed immense challenges in terms of understanding what conformation a G-rich sequence adopts inside the cell and how to specifically target a GQ motif amidst several other GQ-forming sequences. In this context, here we review recent developments in the applications of biophysical tools that use fluorescence readout to probe the GQ structure and recognition in cell-free and cellular environments. First, we provide a detailed discussion on the utility of covalently labeled environment-sensitive fluorescent nucleoside analogs in assessing the subtle difference in GQ structures and their ligand binding abilities. Furthermore, a detailed discussion on structure-specific antibodies and small molecule probes used to visualize and confirm the existence of DNA and RNA GQs in cells is provided. We also highlight the open challenges in the study of tetraplexes (GQ and i-motif structures) and how addressing these challenges by developing new tools and techniques will have a profound impact on tetraplex-directed therapeutic strategies.
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Affiliation(s)
- Sudeshna Manna
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), PuneDr. Homi Bhabha RoadPune 411008India
| | - Seergazhi G. Srivatsan
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), PuneDr. Homi Bhabha RoadPune 411008India
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32
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Onel B, Carver M, Agrawal P, Hurley LH, Yang D. The 3'-end region of the human PDGFR-β core promoter nuclease hypersensitive element forms a mixture of two unique end-insertion G-quadruplexes. Biochim Biophys Acta Gen Subj 2017; 1862:846-854. [PMID: 29288770 DOI: 10.1016/j.bbagen.2017.12.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/16/2017] [Accepted: 12/22/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND While the most stable G-quadruplex formed in the human PDGFR-β promoter nuclease hypersensitive element (NHE) is the 5'-mid G-quadruplex, the 3'-end sequence that contains a 3'-GGA run forms a less stable G-quadruplex. Recently, the 3'-end G-quadruplex was found to be a transcriptional repressor and can be selectively targeted by a small molecule for PDGFR-β downregulation. METHOD We use 1D and 2D high-field NMR, in combination with Dimethylsulfate Footprinting, Circular Dichroism Spectroscopy, and Electrophoretic Mobility Shift Assay. RESULTS We determine that the PDGFR-β extended 3'-end NHE sequence forms two novel end-insertion intramolecular G-quadruplexes that co-exist in equilibrium under physiological salt conditions. One G-quadruplex has a 3'-non-adjacent flanking guanine inserted into the 3'-external tetrad (3'-insertion-G4), and another has a 5'-non-adjacent flanking guanine inserted into the 5'-external tetrad (5'-insertion-G4). The two guanines in the GGA-run move up or down within the G-quadruplex to accommodate the inserted guanine. Each end-insertion G-quadruplex has a low thermal stability as compared to the 5'-mid G-quadruplex, but the selective stabilization of GSA1129 shifts the equilibrium toward the 3'-end G-quadruplex in the PDGFR-β NHE. CONCLUSION An equilibrium mixture of two unique end-insertion intramolecular G-quadruplexes forms in the PDGFR-β NHE 3'-end sequence that contains a GGA-run and non-adjacent guanines in both the 3'- and 5'- flanking segments; the novel end-insertion structures of the 3'-end G-quadruplex are selectively stabilized by GSA1129. GENERAL SIGNIFICANCE We show for the first time that an equilibrium mixture of two unusual end-insertion G-quadruplexes forms in a native promoter sequence and appears to be the molecular recognition for PDGFR-β downregulation.
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Affiliation(s)
- Buket Onel
- Purdue University, College of Pharmacy, Medicinal Chemistry and Molecular Pharmacology, 575 W Stadium Ave, West Lafayette, IN 47907, USA
| | - Megan Carver
- University of Arizona, College of Pharmacy, 1703 East Mabel Street, Tucson, AZ 85721, USA
| | - Prashansa Agrawal
- Case Western Reserve University, Department of Chemistry, Cleveland, OH 44106, USA
| | - Laurence H Hurley
- University of Arizona, College of Pharmacy, 1703 East Mabel Street, Tucson, AZ 85721, USA; BIO5 Institute, 1657 East Helen Street, Tucson, AZ 85721, USA; Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, AZ 85724, USA
| | - Danzhou Yang
- Purdue University, College of Pharmacy, Medicinal Chemistry and Molecular Pharmacology, 575 W Stadium Ave, West Lafayette, IN 47907, USA; Purdue University, Center for Cancer Research, 201 S University St, West Lafayette, IN 47906, USA; Purdue Institute for Drug Discovery, 720 Clinic Dr, West Lafayette, IN 47907, USA.
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33
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Musso L, Mazzini S, Rossini A, Castagnoli L, Scaglioni L, Artali R, Di Nicola M, Zunino F, Dallavalle S. c-MYC G-quadruplex binding by the RNA polymerase I inhibitor BMH-21 and analogues revealed by a combined NMR and biochemical Approach. Biochim Biophys Acta Gen Subj 2017; 1862:615-629. [PMID: 29229300 DOI: 10.1016/j.bbagen.2017.12.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 11/03/2017] [Accepted: 12/07/2017] [Indexed: 02/05/2023]
Abstract
BACKGROUND Pyridoquinazolinecarboxamides have been reported as RNA polymerase I inhibitors and represent a novel class of potential antitumor agents. BMH-21, was reported to intercalate with GC-rich rDNA, resulting in nucleolar stress as a primary mechanism of cytotoxicity. METHODS The interaction of BMH-21 and analogues with DNA G-quadruplex structures was studied by NMR and molecular modelling. The cellular response was investigated in a panel of human tumor cell lines and protein expression was examined by Western Blot analysis. RESULTS AND CONCLUSIONS We explored the ability of BMH-21 and its analogue 2 to bind to G-quadruplex present in the c-MYC promoter, by NMR and molecular modelling studies. We provide evidence that both compounds are not typical DNA intercalators but are effective binders of the tested G-quadruplex. The interaction with c-MYC G-quadruplex was reflected in down-regulation of c-Myc expression in human tumor cells. The inhibitory effect was almost complete in lymphoma cells SUDHL4 characterized by overexpression of c-Myc protein. This downregulation reflected an early and persistent modulation of cMyc mRNA. Given the relevance of c-MYC in regulation of ribosome biogenesis, it is conceivable that the inhibition of c-MYC contributes to the perturbation of nuclear functions and RNA polymerase I activity. Similar experiments with CX-5461, another RNA polymerase I transcription inhibitor, indicate the same behaviour in G-quadruplex stabilization. GENERAL SIGNIFICANCE Our results support the hypothesis that BMH-21 and analogue compounds share the same mechanism, i.e. G-quadruplex binding as a primary event of a cascade leading to inhibition of RNA polymerase I and apoptosis.
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MESH Headings
- Antineoplastic Agents/pharmacology
- Benzothiazoles/pharmacology
- Blotting, Western
- Cell Line, Tumor
- DNA, Neoplasm/drug effects
- DNA, Neoplasm/genetics
- Enzyme Inhibitors/pharmacology
- G-Quadruplexes/drug effects
- Gene Expression Regulation, Neoplastic/drug effects
- Genes, myc/drug effects
- Heterocyclic Compounds, 4 or More Rings/pharmacology
- Humans
- Models, Molecular
- Molecular Docking Simulation
- Molecular Structure
- Naphthyridines/pharmacology
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Nuclear Magnetic Resonance, Biomolecular
- Organelle Biogenesis
- Promoter Regions, Genetic/drug effects
- RNA Polymerase I/antagonists & inhibitors
- Ribosomes/metabolism
- Transcription, Genetic/drug effects
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Affiliation(s)
- Loana Musso
- Department of Food, Environmental and Nutritional Sciences, Division of Chemistry and Molecular Biology, Università degli Studi di Milano, via Celoria 2, I-20133 Milano, Italy
| | - Stefania Mazzini
- Department of Food, Environmental and Nutritional Sciences, Division of Chemistry and Molecular Biology, Università degli Studi di Milano, via Celoria 2, I-20133 Milano, Italy.
| | - Anna Rossini
- Fondazione IRCCS, Istituto Nazionale dei Tumori, via Venezian 1, 20133 Milano, Italy
| | - Lorenzo Castagnoli
- Molecular Targeting Unit, Department of Applied Research and Technological Development, Fondazione IRCCS Istituto Nazionale Tumori, via Venezian 1, 20133 Milano, Italy
| | - Leonardo Scaglioni
- Department of Food, Environmental and Nutritional Sciences, Division of Chemistry and Molecular Biology, Università degli Studi di Milano, via Celoria 2, I-20133 Milano, Italy
| | - Roberto Artali
- Scientia Advice, di Roberto Artali, 20832 Desio, MB, Italy
| | - Massimo Di Nicola
- Fondazione IRCCS, Istituto Nazionale dei Tumori, via Venezian 1, 20133 Milano, Italy
| | - Franco Zunino
- Fondazione IRCCS, Istituto Nazionale dei Tumori, via Venezian 1, 20133 Milano, Italy
| | - Sabrina Dallavalle
- Department of Food, Environmental and Nutritional Sciences, Division of Chemistry and Molecular Biology, Università degli Studi di Milano, via Celoria 2, I-20133 Milano, Italy
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34
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Tan W, Yi L, Zhu Z, Zhang L, Zhou J, Yuan G. Hsa-miR-1587 G-quadruplex formation and dimerization induced by NH 4+, molecular crowding environment and jatrorrhizine derivatives. Talanta 2017; 179:337-343. [PMID: 29310241 DOI: 10.1016/j.talanta.2017.11.041] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 10/23/2017] [Accepted: 11/16/2017] [Indexed: 11/19/2022]
Abstract
A guanine-rich human mature microRNA, miR-1587, was discovered to form stable intramolecular G-quadruplexes in the presence of K+, Na+ and low concentration of NH4+ (25mM) by electrospray ionization mass spectrometry (ESI-MS) combined with circular dichroism (CD) spectroscopy. Furthermore, under high concentration of NH4+ (100mM) or molecular crowding environments, miR-1587 formed a dimeric G-quadruplex through 3'-to-3' stacking of two monomeric G-quadruplex subunits with one ammonium ion sandwiched between the interfaces. Specifically, two synthesized jatrorrhizine derivatives with terminal amine groups could also induce the dimerization of miR-1587 G-quadruplex and formed 1:1 and 2:1 complexes with the dimeric G-quadruplex. In contrast, jatrorrhizine could bind with the dimeric miR-1587 G-quadruplex, but could not induce dimerization of miR-1587 G-quadruplex. These results provide a new strategy to regulate the functions of miR-1587 through induction of G-quadruplex formation and dimerization.
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Affiliation(s)
- Wei Tan
- College of Chemistry and Molecular Engineering, Peking University, 202 Chengfu Road, Haidian District, Beijing 100871, China
| | - Long Yi
- Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Engineering, Beijing 100029, China
| | - Zhentao Zhu
- Beijing Key Laboratory of Bioprocess, Beijing University of Chemical Engineering, Beijing 100029, China
| | - Lulu Zhang
- College of Chemistry and Molecular Engineering, Peking University, 202 Chengfu Road, Haidian District, Beijing 100871, China
| | - Jiang Zhou
- College of Chemistry and Molecular Engineering, Peking University, 202 Chengfu Road, Haidian District, Beijing 100871, China.
| | - Gu Yuan
- College of Chemistry and Molecular Engineering, Peking University, 202 Chengfu Road, Haidian District, Beijing 100871, China.
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35
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Agarwala P, Pal G, Pandey S, Maiti S. Mutagenesis Reveals an Unusual Combination of Guanines in RNA G-Quadruplex Formation. ACS OMEGA 2017; 2:4790-4799. [PMID: 31457759 PMCID: PMC6641730 DOI: 10.1021/acsomega.7b00377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 08/01/2017] [Indexed: 06/10/2023]
Abstract
The classic G-quadruplex motif consists of a continuous array of 3-4 guanine residues with an intermittent loop size of 1-7 nucleotides (G3-4N1-7G3-4N1-7G3-4N1-7G3-4). An RNA G-quadruplex is able to attain only one parallel G-quadruplex topology owing to steric constraints. Investigating the possibilities of the formation of RNA G-quadruplexes with a stretch of sequences deviating from this classic motif will add to the overall conformations of RNA G-quadruplexes, bestowing diversity to this structure. Here, we report unusual combinations of guanine residues involved in RNA G-quadruplex formation in the 5' untranslated region (UTR) of the von Willebrand factor (VWF) mRNA using the mutagenesis approach. Different permutations and combinations of guanine residues form G-quadruplexes. Upon investigation, G-quadruplexes in 5' UTR of VWF mRNA are shown to exhibit an inhibitory function.
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Affiliation(s)
- Prachi Agarwala
- Chemical
and Systems Biology, CSIR-Institute of Genomics
and Integrative Biology, Mall Road, Delhi 110007, India
- Academy
of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | - Gargi Pal
- Academy
of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | - Satyaprakash Pandey
- Chemical
and Systems Biology, CSIR-Institute of Genomics
and Integrative Biology, Mall Road, Delhi 110007, India
- Academy
of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
| | - Souvik Maiti
- Chemical
and Systems Biology, CSIR-Institute of Genomics
and Integrative Biology, Mall Road, Delhi 110007, India
- Academy
of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi 110001, India
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36
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Brown RV, Wang T, Chappeta VR, Wu G, Onel B, Chawla R, Quijada H, Camp SM, Chiang ET, Lassiter QR, Lee C, Phanse S, Turnidge MA, Zhao P, Garcia JGN, Gokhale V, Yang D, Hurley LH. The Consequences of Overlapping G-Quadruplexes and i-Motifs in the Platelet-Derived Growth Factor Receptor β Core Promoter Nuclease Hypersensitive Element Can Explain the Unexpected Effects of Mutations and Provide Opportunities for Selective Targeting of Both Structures by Small Molecules To Downregulate Gene Expression. J Am Chem Soc 2017; 139:7456-7475. [PMID: 28471683 PMCID: PMC5977998 DOI: 10.1021/jacs.6b10028] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The platelet-derived growth factor receptor β (PDGFR-β) signaling pathway is a validated and important target for the treatment of certain malignant and nonmalignant pathologies. We previously identified a G-quadruplex-forming nuclease hypersensitive element (NHE) in the human PDGFR-β promoter that putatively forms four overlapping G-quadruplexes. Therefore, we further investigated the structures and biological roles of the G-quadruplexes and i-motifs in the PDGFR-β NHE with the ultimate goal of demonstrating an alternate and effective strategy for molecularly targeting the PDGFR-β pathway. Significantly, we show that the primary G-quadruplex receptor for repression of PDGFR-β is the 3'-end G-quadruplex, which has a GGA sequence at the 3'-end. Mutation studies using luciferase reporter plasmids highlight a novel set of G-quadruplex point mutations, some of which seem to provide conflicting results on effects on gene expression, prompting further investigation into the effect of these mutations on the i-motif-forming strand. Herein we characterize the formation of an equilibrium between at least two different i-motifs from the cytosine-rich (C-rich) sequence of the PDGFR-β NHE. The apparently conflicting mutation results can be rationalized if we take into account the single base point mutation made in a critical cytosine run in the PDGFR-β NHE that dramatically affects the equilibrium of i-motifs formed from this sequence. We identified a group of ellipticines that targets the G-quadruplexes in the PDGFR-β promoter, and from this series of compounds, we selected the ellipticine analog GSA1129, which selectively targets the 3'-end G-quadruplex, to shift the dynamic equilibrium in the full-length sequence to favor this structure. We also identified a benzothiophene-2-carboxamide (NSC309874) as a PDGFR-β i-motif-interactive compound. In vitro, GSA1129 and NSC309874 downregulate PDGFR-β promoter activity and transcript in the neuroblastoma cell line SK-N-SH at subcytotoxic cell concentrations. GSA1129 also inhibits PDGFR-β-driven cell proliferation and migration. With an established preclinical murine model of acute lung injury, we demonstrate that GSA1129 attenuates endotoxin-mediated acute lung inflammation. Our studies underscore the importance of considering the effects of point mutations on structure formation from the G- and C-rich sequences and provide further evidence for the involvement of both strands and associated structures in the control of gene expression.
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Affiliation(s)
- Robert V. Brown
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, Arizona 85721, United States
| | - Ting Wang
- College of Medicine, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724, United States
| | | | - Guanhui Wu
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, Arizona 85721, United States
| | - Buket Onel
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, Arizona 85721, United States
| | - Reena Chawla
- BIO5 Institute, 1657 East Helen Street, Tucson, Arizona 85721, United States
| | - Hector Quijada
- College of Medicine, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724, United States
| | - Sara M. Camp
- College of Medicine, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724, United States
| | - Eddie T. Chiang
- College of Medicine, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724, United States
| | - Quinea R. Lassiter
- College of Agriculture & Life Sciences, University of Arizona, 1117 East Lowell Street, Tucson, Arizona 85721, United States
| | - Carmen Lee
- College of Agriculture & Life Sciences, University of Arizona, 1117 East Lowell Street, Tucson, Arizona 85721, United States
- College of Science, University of Arizona, 1040 East Fourth Street, Tucson, Arizona 85721, United States
| | - Shivani Phanse
- College of Science, University of Arizona, 1040 East Fourth Street, Tucson, Arizona 85721, United States
| | - Megan A. Turnidge
- College of Science, University of Arizona, 1040 East Fourth Street, Tucson, Arizona 85721, United States
| | - Ping Zhao
- School of Chemistry and Chemical Engineering, Guangdong Pharmaceutical University, No. 280 Waihuandong Road, Education Mega Centre, Guanzhou 510006, Peoples Republic of China
| | - Joe G. N. Garcia
- College of Medicine, University of Arizona, 1501 North Campbell Avenue, Tucson, Arizona 85724, United States
| | - Vijay Gokhale
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, Arizona 85721, United States
- BIO5 Institute, 1657 East Helen Street, Tucson, Arizona 85721, United States
| | - Danzhou Yang
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, Arizona 85721, United States
- BIO5 Institute, 1657 East Helen Street, Tucson, Arizona 85721, United States
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, Arizona 85724, United States
| | - Laurence H. Hurley
- College of Pharmacy, University of Arizona, 1703 East Mabel Street, Tucson, Arizona 85721, United States
- BIO5 Institute, 1657 East Helen Street, Tucson, Arizona 85721, United States
- University of Arizona Cancer Center, 1515 North Campbell Avenue, Tucson, Arizona 85724, United States
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Dolinnaya NG, Ogloblina AM, Yakubovskaya MG. Structure, Properties, and Biological Relevance of the DNA and RNA G-Quadruplexes: Overview 50 Years after Their Discovery. BIOCHEMISTRY (MOSCOW) 2017; 81:1602-1649. [PMID: 28260487 PMCID: PMC7087716 DOI: 10.1134/s0006297916130034] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
G-quadruplexes (G4s), which are known to have important roles in regulation of key biological processes in both normal and pathological cells, are the most actively studied non-canonical structures of nucleic acids. In this review, we summarize the results of studies published in recent years that change significantly scientific views on various aspects of our understanding of quadruplexes. Modern notions on the polymorphism of DNA quadruplexes, on factors affecting thermodynamics and kinetics of G4 folding–unfolding, on structural organization of multiquadruplex systems, and on conformational features of RNA G4s and hybrid DNA–RNA G4s are discussed. Here we report the data on location of G4 sequence motifs in the genomes of eukaryotes, bacteria, and viruses, characterize G4-specific small-molecule ligands and proteins, as well as the mechanisms of their interactions with quadruplexes. New information on the structure and stability of G4s in telomeric DNA and oncogene promoters is discussed as well as proof being provided on the occurrence of G-quadruplexes in cells. Prominence is given to novel experimental techniques (single molecule manipulations, optical and magnetic tweezers, original chemical approaches, G4 detection in situ, in-cell NMR spectroscopy) that facilitate breakthroughs in the investigation of the structure and functions of G-quadruplexes.
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Affiliation(s)
- N G Dolinnaya
- Lomonosov Moscow State University, Department of Chemistry, Moscow, 119991, Russia.
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Wang KB, Li DH, Hu P, Wang WJ, Lin C, Wang J, Lin B, Bai J, Pei YH, Jing YK, Li ZL, Yang D, Hua HM. A Series of β-Carboline Alkaloids from the Seeds of Peganum harmala Show G-Quadruplex Interactions. Org Lett 2016; 18:3398-401. [PMID: 27340903 DOI: 10.1021/acs.orglett.6b01560] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this study, we screened 17 medicinal plants for binding activity to G-quadruplex d(TTGGGTT)4 by (1)H NMR spectroscopy and found that the crude extract of Peganum harmala L. seeds showed the most potential binding activity. Subsequently, (1)H NMR- and bioassay-guided isolation of the extract of P. harmala L. was performed to obtain four pairs of partially racemized β-carboline alkaloids, pegaharmines A-D (1-4). Their structures and absolute configurations were determined by extensive NMR analyses, X-ray crystallography, ECD calculations, and CD exciton chirality approaches. Interestingly, pegaharmine D (4), which showed the strongest G-quadruplex interaction, exhibited significant cytotoxic activity against three cancer cell lines. This work contributed a practical strategy for the discovery of novel G-quadruplex ligands from natural products and provided potential insights for using β-carboline alkaloids as anticancer lead compounds specifically targeting G-quadruplexes.
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Affiliation(s)
- Kai-Bo Wang
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | - Da-Hong Li
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | - Ping Hu
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | - Wen-Jing Wang
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | | | - Jian Wang
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | - Bin Lin
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | - Jiao Bai
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | - Yue-Hu Pei
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | - Yong-Kui Jing
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | - Zhan-Lin Li
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
| | | | - Hui-Ming Hua
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University , Shenyang 110016, Liaoning, P. R. China
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Scaglioni L, Mondelli R, Artali R, Sirtori FR, Mazzini S. Nemorubicin and doxorubicin bind the G-quadruplex sequences of the human telomeres and of the c-MYC promoter element Pu22. Biochim Biophys Acta Gen Subj 2016; 1860:1129-38. [PMID: 26922833 DOI: 10.1016/j.bbagen.2016.02.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 02/12/2016] [Accepted: 02/21/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Intra-molecular G-quadruplex structures are present in the guanine rich regions of human telomeres and were found to be prevalent in gene promoters. More recently, the targeting of c-MYC transcriptional control has been suggested, because the over expression of the c-MYC oncogene is one of the most common aberration found in a wide range of human tumors. METHODS The interaction of nemorubicin and doxorubicin with DNA G-quadruplex structures has been studied by NMR, ESI-MS and molecular modelling, in order to obtain further information about the complex and the multiple mechanisms of action of these drugs. RESULTS AND CONCLUSIONS Nemorubicin intercalates between A3 and G4 of d(TTAGGGT)4 and form cap-complex at the G6pT7 site. The presence of the adenine in this sequence is important for the stabilization of the complex, as was shown by the interaction with d(TTGGGTT)4 and d(TTTGGGT)4, which form only a 1:1 complex. The interaction of doxorubicin with d(TTAGGGT)4 is similar, but the complex appears less stable. Nemorubicin also binds with high efficiency the c-MYC G-quadruplex sequence Pu22, to form a very well defined complex. Two nemorubicin molecules bind to the 3'-end and to the 5'-end, forming an additional plane of stacking over each external G-tetrad. The wild type c-MYCPu22 sequence forms with nemorubicin the same complex. GENERAL SIGNIFICANCE Nemorubicin and doxorubicin, not only intercalate into the duplex DNA, but also result in significant ligands for G-quadruplex DNA segments, stabilizing their structure; this may in part explain the multiple mechanisms of action of their antitumor activity.
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Affiliation(s)
- Leonardo Scaglioni
- Department of Food, Environmental and Nutritional Sciences, Division of Chemistry and Molecular Biology, University of Milan, Via Celoria 2, 20133 Milano, Italy
| | - Rosanna Mondelli
- Department of Food, Environmental and Nutritional Sciences, Division of Chemistry and Molecular Biology, University of Milan, Via Celoria 2, 20133 Milano, Italy
| | | | - Federico Riccardi Sirtori
- Nerviano, Medical Sciences, Oncology-Chemical Core, Technologies Department, viale Pasteur, 10, 20014 Nerviano, Milano, Italy
| | - Stefania Mazzini
- Department of Food, Environmental and Nutritional Sciences, Division of Chemistry and Molecular Biology, University of Milan, Via Celoria 2, 20133 Milano, Italy.
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Onel B, Carver M, Wu G, Timonina D, Kalarn S, Larriva M, Yang D. A New G-Quadruplex with Hairpin Loop Immediately Upstream of the Human BCL2 P1 Promoter Modulates Transcription. J Am Chem Soc 2016; 138:2563-70. [PMID: 26841249 DOI: 10.1021/jacs.5b08596] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The abnormal overexpression of the BCL2 gene is associated with many human tumors. We found a new 28-mer G-quadruplex-forming sequence, P1G4, immediately upstream of the human BCL2 gene P1 promoter. The P1G4 is shown to be a transcription repressor using a promoter-driven luciferase assay; its inhibitory effect can be markedly enhanced by the G-quadruplex-interactive compound TMPyP4. G-quadruplex can readily form in the P1G4 sequence under physiological salt condition as shown by DMS footprinting. P1G4 and previously identified Pu39 G-quadruplexes appear to form independently in adjacent regions in the BCL2 P1 promoter. In the extended BCL2 P1 promoter region containing both Pu39 and P1G4, P1G4 appears to play a more dominant role in repressing the transcriptional activity. Using NMR spectroscopy, the P1G4 G-quadruplex appears to be a novel dynamic equilibrium of two parallel structures, one regular with two 1-nt loops and a 12-nt middle loop and another broken-strand with three 1-nt loops and a 11-nt middle loop; both structures adopt a novel hairpin (stem-loop duplex) conformation in the long loop. The dynamic equilibrium of two closely related structures and the unique hairpin loop conformation are specific to the P1G4 sequence and distinguish the P1G4 quadruplex from other parallel structures. The presence of P1G4 and Pu39 in adjacent regions of the BCL2 P1 promoter suggests a mechanism for precise regulation of BCL2 gene transcription. The unique P1G4 G-quadruplex may provide a specific target for small molecules to modulate BCL2 gene transcription.
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Affiliation(s)
| | - Megan Carver
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona , 1703 E. Mabel St, Tucson, Arizona 85721, United States
| | - Guanhui Wu
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona , 1703 E. Mabel St, Tucson, Arizona 85721, United States
| | | | | | - Marti Larriva
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona , 1703 E. Mabel St, Tucson, Arizona 85721, United States
| | - Danzhou Yang
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona , 1703 E. Mabel St, Tucson, Arizona 85721, United States
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Guanine-vacancy-bearing G-quadruplexes responsive to guanine derivatives. Proc Natl Acad Sci U S A 2015; 112:14581-6. [PMID: 26553979 DOI: 10.1073/pnas.1516925112] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
G-quadruplex structures formed by guanine-rich nucleic acids are implicated in essential physiological and pathological processes and nanodevices. G-quadruplexes are normally composed of four Gn (n ≥ 3) tracts assembled into a core of multiple stacked G-quartet layers. By dimethyl sulfate footprinting, circular dichroism spectroscopy, thermal melting, and photo-cross-linking, here we describe a unique type of intramolecular G-quadruplex that forms with one G2 and three G3 tracts and bears a guanine vacancy (G-vacancy) in one of the G-quartet layers. The G-vacancy can be filled up by a guanine base from GTP or GMP to complete an intact G-quartet by Hoogsteen hydrogen bonding, resulting in significant G-quadruplex stabilization that can effectively alter DNA replication in vitro at physiological concentration of GTP and Mg(2+). A bioinformatic survey shows motifs of such G-quadruplexes are evolutionally selected in genes with unique distribution pattern in both eukaryotic and prokaryotic organisms, implying such G-vacancy-bearing G-quadruplexes are present and play a role in gene regulation. Because guanine derivatives are natural metabolites in cells, the formation of such G-quadruplexes and guanine fill-in (G-fill-in) may grant an environment-responsive regulation in cellular processes. Our findings thus not only expand the sequence definition of G-quadruplex formation, but more importantly, reveal a structural and functional property not seen in the standard canonical G-quadruplexes.
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42
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Lim KW, Jenjaroenpun P, Low ZJ, Khong ZJ, Ng YS, Kuznetsov VA, Phan AT. Duplex stem-loop-containing quadruplex motifs in the human genome: a combined genomic and structural study. Nucleic Acids Res 2015; 43:5630-46. [PMID: 25958397 PMCID: PMC4477648 DOI: 10.1093/nar/gkv355] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 04/02/2015] [Indexed: 12/12/2022] Open
Abstract
Duplex stem-loops and four-stranded G-quadruplexes have been implicated in (patho)biological processes. Overlap of stem-loop- and quadruplex-forming sequences could give rise to quadruplex-duplex hybrids (QDH), which combine features of both structural forms and could exhibit unique properties. Here, we present a combined genomic and structural study of stem-loop-containing quadruplex sequences (SLQS) in the human genome. Based on a maximum loop length of 20 nt, our survey identified 80 307 SLQS, embedded within 60 172 unique clusters. Our analysis suggested that these should cover close to half of total SLQS in the entire genome. Among these, 48 508 SLQS were strand-specifically located in genic/promoter regions, with the majority of genes displaying a low number of SLQS. Notably, genes containing abundant SLQS clusters were strongly associated with brain tissues. Enrichment analysis of SLQS-positive genes and mapping of SLQS onto transcriptional/mutagenesis hotspots and cancer-associated genes, provided a statistical framework supporting the biological involvements of SLQS. In vitro formation of diverse QDH by selective SLQS hits were successfully verified by nuclear magnetic resonance spectroscopy. Folding topologies of two SLQS were elucidated in detail. We also demonstrated that sequence changes at mutation/single-nucleotide polymorphism loci could affect the structural conformations adopted by SLQS. Thus, our predicted SLQS offer novel insights into the potential involvement of QDH in diverse (patho)biological processes and could represent novel regulatory signals.
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Affiliation(s)
- Kah Wai Lim
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Piroon Jenjaroenpun
- Department of Genome and Gene Expression Data Analysis, Bioinformatics Institute, 138671, Singapore
| | - Zhen Jie Low
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Zi Jian Khong
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | - Yi Siang Ng
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | | | - Anh Tuân Phan
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
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Structure-based virtual screening of novel natural alkaloid derivatives as potential binders of h-telo and c-myc DNA G-quadruplex conformations. Molecules 2014; 20:206-23. [PMID: 25547724 PMCID: PMC6272608 DOI: 10.3390/molecules20010206] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 12/15/2014] [Indexed: 01/08/2023] Open
Abstract
Several ligands can bind to the non-canonical G-quadruplex DNA structures thereby stabilizing them. These molecules can act as effective anticancer agents by stabilizing the telomeric regions of DNA or by regulating oncogene expression. In order to better interact with the quartets of G-quadruplex structures, G-binders are generally characterized by a large aromatic core involved in π-π stacking. Some natural flexible cyclic molecules from Traditional Chinese Medicine have shown high binding affinity with G-quadruplex, such as berbamine and many other alkaloids. Using the structural information available on G-quadruplex structures, we performed a high throughput in silico screening of commercially available alkaloid derivative databases by means of a structure-based approach based on docking and molecular dynamics simulations against the human telomeric sequence d[AG3(T2AG3)3] and the c-myc promoter structure. We identified 69 best hits reporting an improved theoretical binding affinity with respect to the active set. Among them, a berberine derivative, already known to remarkably inhibit telomerase activity, was related to a better theoretical affinity versusc-myc.
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Sengar A, Heddi B, Phan AT. Formation of G-quadruplexes in poly-G sequences: structure of a propeller-type parallel-stranded G-quadruplex formed by a G₁₅ stretch. Biochemistry 2014; 53:7718-23. [PMID: 25375976 DOI: 10.1021/bi500990v] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Poly-G sequences are found in different genomes including human and have the potential to form higher-order structures with various applications. Previously, long poly-G sequences were thought to lead to multiple possible ways of G-quadruplex folding, rendering their structural characterization challenging. Here we investigate the structure of G-quadruplexes formed by poly-G sequences d(TTG(n)T), where n = 12 to 19. Our data show the presence of multiple and/or higher-order G-quadruplex structures in most sequences. Strikingly, NMR spectra of the TTG₁₅T sequence containing a stretch of 15 continuous guanines are exceptionally well-resolved and indicate the formation of a well-defined G-quadruplex structure. The NMR solution structure of this sequence revealed a propeller-type parallel-stranded G-quadruplex containing three G-tetrad layers and three single-guanine propeller loops. The same structure can potentially form anywhere along a long G(n) stretch, making it unique for molecular recognition by other cellular molecules.
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Affiliation(s)
- Anjali Sengar
- School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371, Singapore
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45
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Buket ONEL, Clement LIN, DanZhou YANG. DNA G-quadruplex and its potential as anticancer drug target. Sci China Chem 2014; 57:1605-1614. [PMID: 27182219 PMCID: PMC4863707 DOI: 10.1007/s11426-014-5235-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
G-quadruplex secondary structures are four-stranded globular nucleic acid structures form in the specific DNA and RNA G-rich sequences with biological significance such as human telomeres, oncogene-promoter regions, replication initiation sites, and 5' and 3'-untranslated (UTR) regions. The non-canonical G-quadruplex secondary structures can readily form under physiologically relevant ionic conditions and are considered to be new molecular target for cancer therapeutics. This review discusses the essential progress in our lab related to the structures and functions of biologically relevant DNA G-quadruplexes in human gene promoters and telomeres, and the opportunities presented for the development of G-quadruplex-targeted small- molecule drugs.
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Affiliation(s)
- ONEL Buket
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA
| | - LIN Clement
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA
| | - YANG DanZhou
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA
- Department of Pharmacology and Toxicology, University of Arizona, Tucson, AZ 85721, USA
- BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA
- The Arizona Cancer Center, Tucson, AZ 85724, USA
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46
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Adrian M, Ang DJ, Lech CJ, Heddi B, Nicolas A, Phan AT. Structure and conformational dynamics of a stacked dimeric G-quadruplex formed by the human CEB1 minisatellite. J Am Chem Soc 2014; 136:6297-305. [PMID: 24742225 DOI: 10.1021/ja4125274] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CEB1 is a highly polymorphic human minisatellite. In yeast, the size variation of CEB1 tandem arrays has been associated with the capacity of the motif to form G-quadruplexes. Here we report on the NMR solution structure of a G-quadruplex formed by the CEB1 DNA G-rich fragment d(AGGGGGGAGGGAGGGTGG), harboring several G-tracts including one with six continuous guanines. This sequence forms a dimeric G-quadruplex involving the stacking of two subunits, each being a unique snapback parallel-stranded scaffold with three G-tetrad layers, three double-chain-reversal loops, and a V-shaped loop. The two subunits are stacked at their 5'-end tetrads, and multiple stacking rotamers may be present due to a high symmetry at the stacking interface. There is a conformational exchange in the millisecond time scale involving a swapping motion between two bases of the six-guanine tract. Our results not only add to the understanding of how the G-quadruplex formation in human minisatellite leads to genetic instability but also address the fundamental questions regarding stacking of G-quadruplexes and how a long continuous G-tract participates in the structure and conformational dynamics of G-quadruplexes.
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Affiliation(s)
- Michael Adrian
- School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371, Singapore
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47
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Amrane S, Kerkour A, Bedrat A, Vialet B, Andreola ML, Mergny JL. Topology of a DNA G-quadruplex structure formed in the HIV-1 promoter: a potential target for anti-HIV drug development. J Am Chem Soc 2014; 136:5249-52. [PMID: 24649937 DOI: 10.1021/ja501500c] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nucleic acid sequences containing guanine tracts are able to adopt noncanonical four-stranded nucleic acid structures called G-quadruplexes (G4s). These structures are based on the stacking of two or more G-tetrads; each tetrad is a planar association of four guanines held together by eight hydrogen bonds. In this study, we analyzed a conserved G-rich region from HIV-1 promoter that is known to regulate the transcription of the HIV-1 provirus. Strikingly, our analysis of an alignment of 1684 HIV-1 sequences from this region showed a high conservation of the ability to form G4 structures despite a lower conservation of the nucleotide primary sequence. Using NMR spectroscopy, we determined the G4 topology adopted by a DNA sequence from this region (HIV-PRO1: 5' TGGCCTGGGCGGGACTGGG 3'). This DNA fragment formed a stable two G-tetrad antiparallel G4 with an additional Watson-Crick CG base pair. This hybrid structure may be critical for HIV-1 gene expression and is potentially a novel target for anti-HIV-1 drug development.
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Martadinata H, Phan AT. Formation of a stacked dimeric G-quadruplex containing bulges by the 5'-terminal region of human telomerase RNA (hTERC). Biochemistry 2014; 53:1595-600. [PMID: 24601523 DOI: 10.1021/bi4015727] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigate the structure formed by the first 18-nt of the 5'-terminal region of the human telomerase RNA (hTERC or hTR) using gel electrophoresis and UV, CD, and NMR spectroscopy. Our data suggest that this 18-nt sequence, r(GGGUUGCGGAGGGUGGGC), can form a stacked dimeric G-quadruplex in potassium solution. The two subunits, each being a three-layer parallel-stranded G-quadruplex with a cytosine bulge, are stacked at their 5'-end. The formation of this stacked dimeric G-quadruplex containing bulges could be biologically relevant for the dimerization and other interactions of the active human telomerase.
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Affiliation(s)
- Herry Martadinata
- School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371
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49
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Tateishi-Karimata H, Isono N, Sugimoto N. New insights into transcription fidelity: thermal stability of non-canonical structures in template DNA regulates transcriptional arrest, pause, and slippage. PLoS One 2014; 9:e90580. [PMID: 24594642 PMCID: PMC3940900 DOI: 10.1371/journal.pone.0090580] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 02/04/2014] [Indexed: 11/25/2022] Open
Abstract
The thermal stability and topology of non-canonical structures of G-quadruplexes and hairpins in template DNA were investigated, and the effect of non-canonical structures on transcription fidelity was evaluated quantitatively. We designed ten template DNAs: A linear sequence that does not have significant higher-order structure, three sequences that form hairpin structures, and six sequences that form G-quadruplex structures with different stabilities. Templates with non-canonical structures induced the production of an arrested, a slipped, and a full-length transcript, whereas the linear sequence produced only a full-length transcript. The efficiency of production for run-off transcripts (full-length and slipped transcripts) from templates that formed the non-canonical structures was lower than that from the linear. G-quadruplex structures were more effective inhibitors of full-length product formation than were hairpin structure even when the stability of the G-quadruplex in an aqueous solution was the same as that of the hairpin. We considered that intra-polymerase conditions may differentially affect the stability of non-canonical structures. The values of transcription efficiencies of run-off or arrest transcripts were correlated with stabilities of non-canonical structures in the intra-polymerase condition mimicked by 20 wt% polyethylene glycol (PEG). Transcriptional arrest was induced when the stability of the G-quadruplex structure (−ΔGo37) in the presence of 20 wt% PEG was more than 8.2 kcal mol−1. Thus, values of stability in the presence of 20 wt% PEG are an important indicator of transcription perturbation. Our results further our understanding of the impact of template structure on the transcription process and may guide logical design of transcription-regulating drugs.
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Affiliation(s)
- Hisae Tateishi-Karimata
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, Kobe, Japan
| | - Noburu Isono
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, Kobe, Japan
| | - Naoki Sugimoto
- Frontier Institute for Biomolecular Engineering Research (FIBER), Konan University, Kobe, Japan
- Faculty of Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, Kobe, Japan
- * E-mail:
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Tan W, Zhou J, Yuan G. Electrospray ionization mass spectrometry probing of binding affinity of berbamine, a flexible cyclic alkaloid from traditional Chinese medicine, with G-quadruplex DNA. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:143-147. [PMID: 24285399 DOI: 10.1002/rcm.6763] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 10/05/2013] [Accepted: 10/05/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE Classic G-quadruplex binders typically have a large aromatic core and interact with G-quadruplexes through π-π stacking with the quartets. There are rather few reports on natural flexible cyclic molecule from traditional Chinese medicine which has high binding affinity with G-quadruplex. METHODS Electrospray ionization mass spectrometry (ESI-MS) experiments were performed to evaluate the binding affinities of a natural alkaloid, berbamine, with seven G-quadruplexes. Furthermore, we utilized autodock4 analysis to uncover the binding mode of berbamine with the G-quadruplex. RESULTS ESI-MS experiments showed that berbamine has the best binding affinity toward the (GGA)8 G-quadruplex compared with the other six G-quadruplexes. Autodock4 analysis indicated that berbamine interacted with the (GGA)8 G-quadruplex through hydrogen bonding and van der Waals forces with a binding site at the lateral groove formed by DG8-DA9-DA15-DG16. CONCLUSIONS In this study, we discovered a novel G-quadruplex binder, berbamine, which has high binding affinity toward the (GGA)8 G-quadruplex. This study provided important clues regarding the probing of small molecule from traditional Chinese medicine which can target the G-quadruplex with high affinity.
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Affiliation(s)
- Wei Tan
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
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