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Chen JL, Taghavi A, Frank AJ, Fountain MA, Choudhary S, Roy S, Childs-Disney JL, Disney MD. Structures of small molecules bound to RNA repeat expansions that cause Huntington's disease-like 2 and myotonic dystrophy type 1. Bioorg Med Chem Lett 2024:129888. [PMID: 39002937 DOI: 10.1016/j.bmcl.2024.129888] [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: 06/08/2024] [Accepted: 07/10/2024] [Indexed: 07/15/2024]
Abstract
Trinucleotide repeat expansions fold into long, stable hairpins and cause a variety of incurable RNA gain-of-function diseases such as Huntington's disease, the myotonic dystrophies, and spinocerebellar ataxias. One approach for treating these diseases is to bind small molecules to the structured RNAs. Both Huntington's disease-like 2 (HDL2) and myotonic dystrophy type 1 (DM1) are caused by a r(CUG) repeat expansion, or r(CUG)exp. The RNA folds into a hairpin structure with a periodic array of 1 × 1 nucleotide UU loops (5'CUG/3'GUC; where the underlined nucleotides indicate the Us in the internal loop) that sequester various RNA-binding proteins (RBP) and hence the source of its gain-of-function. Here, we report NMR-refined structures of single 5'CUG/3'GUC motifs in complex with three different small molecules, a di-guandinobenzoate (1), a derivative of 1 where the guanidino groups have been exchanged for imidazole (2), and a quinoline with improved drug-like properties (3). These structures were determined using nuclear magnetic resonance (NMR) spectroscopy and simulated annealing with restrained molecular dynamics (MD). Compounds 1, 2, and 3 formed stacking and hydrogen bonding interactions with the 5'CUG/3'GUC motif. Compound 3 also formed van der Waals interactions with the internal loop. The global structure of each RNA-small molecule complexes retains an A-form conformation, while the internal loops are still dynamic but to a lesser extent compared to the unbound form. These results aid our understanding of ligand-RNA interactions and enable structure-based design of small molecules with improved binding affinity for and biological activity against r(CUG)exp. As the first ever reported structures of RNA r(CUG) repeats bound to ligands, these structures can enable virtual screening campaigns combined with machine learning assisted de novo design.
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Affiliation(s)
- Jonathan L Chen
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA; Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Amirhossein Taghavi
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Alexander J Frank
- Department of Chemistry and Biochemistry, State University of New York at Fredonia, Fredonia, NY 14063, USA
| | - Matthew A Fountain
- Department of Chemistry and Biochemistry, State University of New York at Fredonia, Fredonia, NY 14063, USA
| | - Shruti Choudhary
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Soma Roy
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Jessica L Childs-Disney
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA; Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA.
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2
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Chen JL, Taghavi A, Frank AJ, Fountain MA, Choudhary S, Roy S, Childs-Disney JL, Disney MD. NMR structures of small molecules bound to a model of an RNA CUG repeat expansion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.21.600119. [PMID: 38948793 PMCID: PMC11213127 DOI: 10.1101/2024.06.21.600119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Trinucleotide repeat expansions fold into long, stable hairpins and cause a variety of incurable RNA gain-of-function diseases such as Huntington's disease, the myotonic dystrophies, and spinocerebellar ataxias. One approach for treating these diseases is to bind small molecules to the structured RNAs. Both Huntington's disease-like 2 (HDL2) and myotonic dystrophy type 1 (DM1) are caused by a r(CUG) repeat expansion, or r(CUG)exp. The RNA folds into a hairpin structure with a periodic array of 1×1 nucleotide UU loops (5'CUG/3'GUC; where the underlined nucleotides indicate the Us in the internal loop) that sequester various RNA-binding proteins (RBP) and hence the source of its gain-of-function. Here, we report NMR-refined structures of single 5'CUG/3'GUC motifs in complex with three different small molecules, a di-guandinobenzoate (1), a derivative of 1 where the guanidino groups have been exchanged for imidazole (2), and a quinoline with improved drug-like properties (3). These structures were determined using nuclear magnetic resonance (NMR) spectroscopy and simulated annealing with restrained molecular dynamics (MD). Compounds 1, 2, and 3 formed stacking and hydrogen bonding interactions with the 5'CUG/3'GUC motif. Compound 3 also formed van der Waals interactions with the internal loop. The global structure of each RNA-small molecule complexes retains an A-form conformation, while the internal loops are still dynamic but to a lesser extent compared to the unbound form. These results aid our understanding of ligand-RNA interactions and enable structure-based design of small molecules with improved binding affinity for and biological activity against r(CUG)exp. As the first ever reported structures of RNA r(CUG) repeats bound to ligands, these structures can enable virtual screening campaigns combined with machine learning assisted de novo design.
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Affiliation(s)
- Jonathan L. Chen
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
- Department of Biochemistry and Biophysics, Center for RNA Biology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Amirhossein Taghavi
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Alexander J. Frank
- Department of Chemistry and Biochemistry, State University of New York at Fredonia, Fredonia, NY 14063, USA
| | - Matthew A. Fountain
- Department of Chemistry and Biochemistry, State University of New York at Fredonia, Fredonia, NY 14063, USA
| | - Shruti Choudhary
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Soma Roy
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Jessica L. Childs-Disney
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Matthew D. Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
- Department of Chemistry, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, 130 Scripps Way, Jupiter, FL 33458, USA
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3
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Soueid DM, Garner AL. Adaptation of RiPCA for the Live-Cell Detection of mRNA-Protein Interactions. Biochemistry 2023; 62:3323-3336. [PMID: 37963240 DOI: 10.1021/acs.biochem.3c00334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
RNA-binding proteins (RBPs) act as essential regulators of cell fate decisions, through their ability to bind and regulate the activity of cellular RNAs. For protein-coding mRNAs, RBPs control the localization, stability, degradation, and ultimately translation of mRNAs to impact gene expression. Disruption of the vast network of mRNA-protein interactions has been implicated in many human diseases, and accordingly, targeting these interactions has surfaced as a new frontier in RNA-targeted drug discovery. To catalyze this new field, methods are needed to enable the detection and subsequent screening of mRNA-RBP interactions, particularly in live cells. Using our laboratory's RNA-interaction with Protein-mediated Complementation Assay (RiPCA) technology, herein we describe its application to mRNA-protein interactions and present a guide for the development of future RiPCA assays for structurally diverse classes of mRNA-protein interactions.
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Affiliation(s)
- Dalia M Soueid
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Amanda L Garner
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
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4
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Gibaut QR, Bush JA, Tong Y, Baisden JT, Taghavi A, Olafson H, Yao X, Childs-Disney JL, Wang ET, Disney MD. Transcriptome-Wide Studies of RNA-Targeted Small Molecules Provide a Simple and Selective r(CUG) exp Degrader in Myotonic Dystrophy. ACS CENTRAL SCIENCE 2023; 9:1342-1353. [PMID: 37521782 PMCID: PMC10375898 DOI: 10.1021/acscentsci.2c01223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Indexed: 08/01/2023]
Abstract
Myotonic dystrophy type 1 (DM1) is caused by a highly structured RNA repeat expansion, r(CUG)exp, harbored in the 3' untranslated region (3' UTR) of dystrophia myotonica protein kinase (DMPK) mRNA and drives disease through a gain-of-function mechanism. A panel of low-molecular-weight fragments capable of reacting with RNA upon UV irradiation was studied for cross-linking to r(CUG)expin vitro, affording perimidin-2-amine diazirine (1) that bound to r(CUG)exp. The interactions between the small molecule and RNA were further studied by nuclear magnetic resonance (NMR) spectroscopy and molecular modeling. Binding of 1 in DM1 myotubes was profiled transcriptome-wide, identifying 12 transcripts including DMPK that were bound by 1. Augmenting the functionality of 1 with cleaving capability created a chimeric degrader that specifically targets r(CUG)exp for elimination. The degrader broadly improved DM1-associated defects as assessed by RNA-seq, while having limited effects on healthy myotubes. This study (i) provides a platform to investigate molecular recognition of ligands directly in disease-affected cells; (ii) illustrates that RNA degraders can be more specific than the binders from which they are derived; and (iii) suggests that repeating transcripts can be selectively degraded due to the presence of multiple ligand binding sites.
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Affiliation(s)
- Quentin
M. R. Gibaut
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jessica A. Bush
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Yuquan Tong
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jared T. Baisden
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Amirhossein Taghavi
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Hailey Olafson
- Center
for NeuroGenetics, University of Florida, Gainesville, Florida 32610, United States
- Department
of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, Florida 32610, United States
| | - Xiyuan Yao
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jessica L. Childs-Disney
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Eric T. Wang
- Center
for NeuroGenetics, University of Florida, Gainesville, Florida 32610, United States
- Department
of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, Florida 32610, United States
| | - Matthew D. Disney
- The
Department of Chemistry, UF Scripps Biomedical
Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
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5
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Morishita EC. Discovery of RNA-targeted small molecules through the merging of experimental and computational technologies. Expert Opin Drug Discov 2023; 18:207-226. [PMID: 36322542 DOI: 10.1080/17460441.2022.2134852] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The field of RNA-targeted small molecules is rapidly evolving, owing to the advances in experimental and computational technologies. With the identification of several bioactive small molecules that target RNA, including the FDA-approved risdiplam, the biopharmaceutical industry is gaining confidence in the field. This review, based on the literature obtained from PubMed, aims to disseminate information about the various technologies developed for targeting RNA with small molecules and propose areas for improvement to develop drugs more efficiently, particularly those linked to diseases with unmet medical needs. AREAS COVERED The technologies for the identification of RNA targets, screening of chemical libraries against RNA, assessing the bioactivity and target engagement of the hit compounds, structure determination, and hit-to-lead optimization are reviewed. Along with the description of the technologies, their strengths, limitations, and examples of how they can impact drug discovery are provided. EXPERT OPINION Many existing technologies employed for protein targets have been repurposed for use in the discovery of RNA-targeted small molecules. In addition, technologies tailored for RNA targets have been developed. Nevertheless, more improvements are necessary, such as artificial intelligence to dissect important RNA structures and RNA-small-molecule interactions and more powerful chemical probing and structure prediction techniques.
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6
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Gibaut QMR, Akahori Y, Bush JA, Taghavi A, Tanaka T, Aikawa H, Ryan LS, Paegel BM, Disney MD. Study of an RNA-Focused DNA-Encoded Library Informs Design of a Degrader of a r(CUG) Repeat Expansion. J Am Chem Soc 2022; 144:21972-21979. [PMID: 36399603 PMCID: PMC9878440 DOI: 10.1021/jacs.2c08883] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A solid-phase DNA-encoded library (DEL) was studied for binding the RNA repeat expansion r(CUG)exp, the causative agent of the most common form of adult-onset muscular dystrophy, myotonic dystrophy type 1 (DM1). A variety of uncharged and novel RNA binders were identified to selectively bind r(CUG)exp by using a two-color flow cytometry screen. The cellular activity of one binder was augmented by attaching it with a module that directly cleaves r(CUG)exp. In DM1 patient-derived muscle cells, the compound specifically bound r(CUG)exp and allele-specifically eliminated r(CUG)exp, improving disease-associated defects. The approaches herein can be used to identify and optimize ligands and bind RNA that can be further augmented for functionality including degradation.
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Affiliation(s)
- Quentin M. R. Gibaut
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Yoshihiro Akahori
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Jessica A. Bush
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Amirhossein Taghavi
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Toru Tanaka
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Haruo Aikawa
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Lucas S. Ryan
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
| | - Brian M. Paegel
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States; Department of Chemistry and Pharmaceutical Sciences, University of California, Irvine, California 92617, United States
| | - Matthew D. Disney
- Department of Chemistry, UF Scripps Biomedical Research and The Scripps Research Institute, Jupiter, Florida 33458, United States
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7
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Ni J, Cheng X, Ni T, Liang J. Identifying SM-miRNA associations based on layer attention graph convolutional network and matrix decomposition. Front Mol Biosci 2022; 9:1009099. [PMID: 36504714 PMCID: PMC9732030 DOI: 10.3389/fmolb.2022.1009099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/03/2022] [Indexed: 11/27/2022] Open
Abstract
The accurate prediction of potential associations between microRNAs (miRNAs) and small molecule (SM) drugs can enhance our knowledge of how SM cures endogenous miRNA-related diseases. Given that traditional methods for predicting SM-miRNA associations are time-consuming and arduous, a number of computational models have been proposed to anticipate the potential SM-miRNA associations. However, several of these strategies failed to eliminate noise from the known SM-miRNA association information or failed to prioritize the most significant known SM-miRNA associations. Therefore, we proposed a model of Graph Convolutional Network with Layer Attention mechanism for SM-MiRNA Association prediction (GCNLASMMA). Firstly, we obtained the new SM-miRNA associations by matrix decomposition. The new SM-miRNA associations, as well as the integrated SM similarity and miRNA similarity were subsequently incorporated into a heterogeneous network. Finally, a graph convolutional network with an attention mechanism was used to compute the reconstructed SM-miRNA association matrix. Furthermore, four types of cross validations and two types of case studies were performed to assess the performance of GCNLASMMA. In cross validation, global Leave-One-Out Cross Validation (LOOCV), miRNA-fixed LOOCV, SM-fixed LOOCV and 5-fold cross-validation achieved excellent performance. Numerous hypothesized associations in case studies were confirmed by experimental literatures. All of these results confirmed that GCNLASMMA is a trustworthy association inference method.
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8
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Childs-Disney JL, Yang X, Gibaut QMR, Tong Y, Batey RT, Disney MD. Targeting RNA structures with small molecules. Nat Rev Drug Discov 2022; 21:736-762. [PMID: 35941229 PMCID: PMC9360655 DOI: 10.1038/s41573-022-00521-4] [Citation(s) in RCA: 159] [Impact Index Per Article: 79.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2022] [Indexed: 01/07/2023]
Abstract
RNA adopts 3D structures that confer varied functional roles in human biology and dysfunction in disease. Approaches to therapeutically target RNA structures with small molecules are being actively pursued, aided by key advances in the field including the development of computational tools that predict evolutionarily conserved RNA structures, as well as strategies that expand mode of action and facilitate interactions with cellular machinery. Existing RNA-targeted small molecules use a range of mechanisms including directing splicing - by acting as molecular glues with cellular proteins (such as branaplam and the FDA-approved risdiplam), inhibition of translation of undruggable proteins and deactivation of functional structures in noncoding RNAs. Here, we describe strategies to identify, validate and optimize small molecules that target the functional transcriptome, laying out a roadmap to advance these agents into the next decade.
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Affiliation(s)
| | - Xueyi Yang
- Department of Chemistry, Scripps Research, Jupiter, FL, USA
| | | | - Yuquan Tong
- Department of Chemistry, Scripps Research, Jupiter, FL, USA
| | - Robert T Batey
- Department of Biochemistry, University of Colorado, Boulder, CO, USA.
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9
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Martin WJ, Grandi P, Marcia M. Screening strategies for identifying RNA- and ribonucleoprotein-targeted compounds. Trends Pharmacol Sci 2021; 42:758-771. [PMID: 34215444 DOI: 10.1016/j.tips.2021.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/16/2021] [Accepted: 06/02/2021] [Indexed: 12/23/2022]
Abstract
The past few years have witnessed important breakthroughs in the identification of compounds that specifically bind and regulate RNAs and in optimizing them for therapeutic use. Here, we review successful and unsuccessful approaches in screening for RNA-targeted small molecules. We discuss advantages and disadvantages of the different screening techniques and variables that affect the outcome of RNA-screening projects. We also highlight key challenges that hamper the development of quality RNA ligands, especially the still-low availability of RNA-specific compound libraries and the poor understanding of RNA structural dynamics. We conclude that the development of new RNA-targeting drugs would greatly benefit from integration of the power of high-throughput screening technologies with improved biochemical, structural, and computational characterization of RNA targets.
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Affiliation(s)
- William J Martin
- Cellzome GmbH, Functional Genomics R&D, GlaxoSmithKline, 69117 Heidelberg, Germany; European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Paola Grandi
- Cellzome GmbH, Functional Genomics R&D, GlaxoSmithKline, 69117 Heidelberg, Germany
| | - Marco Marcia
- European Molecular Biology Laboratory (EMBL) Grenoble, 71 Avenue des Martyrs, Grenoble 38042, France.
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10
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Vezina-Dawod S, Angelbello AJ, Choudhary S, Wang KW, Yildirim I, Disney MD. Massively Parallel Optimization of the Linker Domain in Small Molecule Dimers Targeting a Toxic r(CUG) Repeat Expansion. ACS Med Chem Lett 2021; 12:907-914. [PMID: 34141068 PMCID: PMC8201483 DOI: 10.1021/acsmedchemlett.1c00027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/23/2021] [Indexed: 12/30/2022] Open
Abstract
RNA contributes to disease pathobiology and is an important therapeutic target. The downstream biology of disease-causing RNAs can be short-circuited with small molecules that recognize structured regions. The discovery and optimization of small molecules interacting with RNA is, however, challenging. Herein, we demonstrate a massively parallel one-bead-one-compound methodology, employed to optimize the linker region of a dimeric compound that binds the toxic r(CUG) repeat expansion [r(CUG)exp] causative of myotonic dystrophy type 1 (DM1). Indeed, affinity selection on a 331,776-member library allowed the discovery of a compound with enhanced potency both in vitro (10-fold) and in DM1-patient-derived myotubes (5-fold). Molecular dynamics simulations revealed additional interactions between the optimized linker and the RNA, resulting in ca. 10 kcal/mol lower binding free energy. The compound was conjugated to a cleavage module, which directly cleaved the transcript harboring the r(CUG)exp and alleviated disease-associated defects.
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Affiliation(s)
- Simon Vezina-Dawod
- Department
of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Alicia J. Angelbello
- Department
of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Shruti Choudhary
- Department
of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Kye Won Wang
- Department
of Chemistry, Florida Atlantic University, Jupiter, Florida 33458, United States
| | - Ilyas Yildirim
- Department
of Chemistry, Florida Atlantic University, Jupiter, Florida 33458, United States
| | - Matthew D. Disney
- Department
of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
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11
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Wagner-Griffin S, Abe M, Benhamou RI, Angelbello AJ, Vishnu K, Chen JL, Childs-Disney JL, Disney MD. A Druglike Small Molecule that Targets r(CCUG) Repeats in Myotonic Dystrophy Type 2 Facilitates Degradation by RNA Quality Control Pathways. J Med Chem 2021; 64:8474-8485. [PMID: 34101465 DOI: 10.1021/acs.jmedchem.1c00414] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Myotonic dystrophy type 2 (DM2) is one of >40 microsatellite disorders caused by RNA repeat expansions. The DM2 repeat expansion, r(CCUG)exp (where "exp" denotes expanded repeating nucleotides), is harbored in intron 1 of the CCHC-type zinc finger nucleic acid binding protein (CNBP). The expanded RNA repeat causes disease by a gain-of-function mechanism, sequestering various RNA-binding proteins including the pre-mRNA splicing regulator MBNL1. Sequestration of MBNL1 results in its loss-of-function and concomitant deregulation of the alternative splicing of its native substrates. Notably, this r(CCUG)exp causes retention of intron 1 in the mature CNBP mRNA. Herein, we report druglike small molecules that bind the structure adopted by r(CCUG)exp and improve DM2-associated defects. These small molecules were optimized from screening hits from an RNA-focused small-molecule library to afford a compound that binds r(CCUG)exp specifically and with nanomolar affinity, facilitates endogenous degradation of the aberrantly retained intron in which it is harbored, and rescues alternative splicing defects.
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Affiliation(s)
- Sarah Wagner-Griffin
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Masahito Abe
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Raphael I Benhamou
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Alicia J Angelbello
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Kamalakannan Vishnu
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Jonathan L Chen
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Jessica L Childs-Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
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12
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Ondono R, Lirio Á, Elvira C, Álvarez-Marimon E, Provenzano C, Cardinali B, Pérez-Alonso M, Perálvarez-Marín A, Borrell JI, Falcone G, Estrada-Tejedor R. Design of novel small molecule base-pair recognizers of toxic CUG RNA transcripts characteristics of DM1. Comput Struct Biotechnol J 2020; 19:51-61. [PMID: 33363709 PMCID: PMC7753043 DOI: 10.1016/j.csbj.2020.11.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 11/25/2020] [Accepted: 11/28/2020] [Indexed: 01/11/2023] Open
Abstract
Myotonic Dystrophy type 1 (DM1) is an incurable neuromuscular disorder caused by toxic DMPK transcripts that carry CUG repeat expansions in the 3' untranslated region (3'UTR). The intrinsic complexity and lack of crystallographic data makes noncoding RNA regions challenging targets to study in the field of drug discovery. In DM1, toxic transcripts tend to stall in the nuclei forming complex inclusion bodies called foci and sequester many essential alternative splicing factors such as Muscleblind-like 1 (MBNL1). Most DM1 phenotypic features stem from the reduced availability of free MBNL1 and therefore many therapeutic efforts are focused on recovering its normal activity. For that purpose, herein we present pyrido[2,3-d]pyrimidin-7-(8H)-ones, a privileged scaffold showing remarkable biological activity against many targets involved in human disorders including cancer and viral diseases. Their combination with a flexible linker meets the requirements to stabilise DM1 toxic transcripts, and therefore, enabling the release of MBNL1. Therefore, a set of novel pyrido[2,3-d]pyrimidin-7-(8H)-ones derivatives (1a-e) were obtained using click chemistry. 1a exerted over 20% MBNL1 recovery on DM1 toxic RNA activity in primary cell biology studies using patient-derived myoblasts. 1a promising anti DM1 activity may lead to subsequent generations of ligands, highlighting a new affordable treatment against DM1.
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Affiliation(s)
- Raul Ondono
- IQS School of Engineering, Universitat Ramon Llull, Barcelona, Spain
| | - Ángel Lirio
- IQS School of Engineering, Universitat Ramon Llull, Barcelona, Spain
| | - Carlos Elvira
- IQS School of Engineering, Universitat Ramon Llull, Barcelona, Spain
| | - Elena Álvarez-Marimon
- Biophysics Unit, Department of Biochemistry and Molecular Biology, School of Medicine, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - Claudia Provenzano
- Institute of Biochemistry and Cell Biology, National Research Council, Monterotondo, Rome, Italy
| | - Beatrice Cardinali
- Institute of Biochemistry and Cell Biology, National Research Council, Monterotondo, Rome, Italy
| | - Manuel Pérez-Alonso
- Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine, University of Valencia, Valencia, Spain
| | - Alex Perálvarez-Marín
- Biophysics Unit, Department of Biochemistry and Molecular Biology, School of Medicine, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
| | - José I. Borrell
- IQS School of Engineering, Universitat Ramon Llull, Barcelona, Spain
| | - Germana Falcone
- Institute of Biochemistry and Cell Biology, National Research Council, Monterotondo, Rome, Italy
| | - Roger Estrada-Tejedor
- IQS School of Engineering, Universitat Ramon Llull, Barcelona, Spain
- Corresponding author.
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13
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Benhamou RI, Vezina-Dawod S, Choudhary S, Won Wang K, Meyer SM, Yildirim I, Disney MD. Macrocyclization of a Ligand Targeting a Toxic RNA Dramatically Improves Potency. Chembiochem 2020; 21:3229-3233. [PMID: 32649032 PMCID: PMC7674229 DOI: 10.1002/cbic.202000445] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/21/2022]
Abstract
RNA molecules both contribute to and are causative of many human diseases. One method to perturb RNA function is to target its structure with small molecules. However, discovering bioactive ligands for RNA targets is challenging. Here, we show that the bioactivity of a linear dimeric ligand that inactivates the RNA trinucleotide repeat expansion that causes myotonic dystrophy type 1 [DM1; r(CUG)exp ] can be improved by macrocyclization. Indeed, the macrocyclic compound is ten times more potent than the linear compound for improving DM1-associated defects in cells, including in patient-derived myotubes (muscle cells). This enhancement in potency is due to the macrocycle's increased affinity and selectively for the target, which inhibit r(CUG)exp 's toxic interaction with muscleblind-like 1 (MBNL1), and its superior cell permeability. Macrocyclization could prove to be an effective way to enhance the bioactivity of modularly assembled ligands targeting RNA.
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Affiliation(s)
- Raphael I Benhamou
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Simon Vezina-Dawod
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Shruti Choudhary
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Kye Won Wang
- Department of Chemistry, Florida Atlantic University, John D. MacArthur Campus, Jupiter, FL 33458, USA
| | - Samantha M Meyer
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Ilyas Yildirim
- Department of Chemistry, Florida Atlantic University, John D. MacArthur Campus, Jupiter, FL 33458, USA
| | - Matthew D Disney
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
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14
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Angelbello AJ, Benhamou RI, Rzuczek SG, Choudhary S, Tang Z, Chen JL, Roy M, Wang KW, Yildirim I, Jun AS, Thornton CA, Disney MD. A Small Molecule that Binds an RNA Repeat Expansion Stimulates Its Decay via the Exosome Complex. Cell Chem Biol 2020; 28:34-45.e6. [PMID: 33157036 DOI: 10.1016/j.chembiol.2020.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/08/2020] [Accepted: 10/16/2020] [Indexed: 12/12/2022]
Abstract
Many diseases are caused by toxic RNA repeats. Herein, we designed a lead small molecule that binds the structure of the r(CUG) repeat expansion [r(CUG)exp] that causes myotonic dystrophy type 1 (DM1) and Fuchs endothelial corneal dystrophy (FECD) and rescues disease biology in patient-derived cells and in vivo. Interestingly, the compound's downstream effects are different in the two diseases, owing to the location of the repeat expansion. In DM1, r(CUG)exp is harbored in the 3' untranslated region, and the compound has no effect on the mRNA's abundance. In FECD, however, r(CUG)exp is located in an intron, and the small molecule facilitates excision of the intron, which is then degraded by the RNA exosome complex. Thus, structure-specific, RNA-targeting small molecules can act disease specifically to affect biology, either by disabling the gain-of-function mechanism (DM1) or by stimulating quality control pathways to rid a disease-affected cell of a toxic RNA (FECD).
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Affiliation(s)
- Alicia J Angelbello
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Raphael I Benhamou
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Suzanne G Rzuczek
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Shruti Choudhary
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Zhenzhi Tang
- Department of Neurology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - Jonathan L Chen
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Madhuparna Roy
- Wilmer Eye Institute, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA
| | - Kye Won Wang
- Department of Chemistry, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Ilyas Yildirim
- Department of Chemistry, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Albert S Jun
- Wilmer Eye Institute, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA
| | - Charles A Thornton
- Department of Neurology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA
| | - Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458, USA.
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15
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Busby SA, Carbonneau S, Concannon J, Dumelin CE, Lee Y, Numao S, Renaud N, Smith TM, Auld DS. Advancements in Assay Technologies and Strategies to Enable Drug Discovery. ACS Chem Biol 2020; 15:2636-2648. [PMID: 32880443 DOI: 10.1021/acschembio.0c00495] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Assays drive drug discovery from the exploratory phases to the clinical testing of drug candidates. As such, numerous assay technologies and methodologies have arisen to support drug discovery efforts. Robust identification and characterization of tractable chemical matter requires biochemical, biophysical, and cellular approaches and often benefits from high-throughput methods. To increase throughput, efforts have been made to provide assays in miniaturized volumes which can be arrayed in microtiter plates to support the testing of as many as 100,000 samples/day. Alongside these efforts has been the growth of microtiter plate-free formats with encoded libraries that can support the screening of billions of compounds, a hunt for new drug modalities, as well as emphasis on more disease relevant formats using complex cell models of disease states. This review will focus on recent developments in high-throughput assay technologies applied to identify starting points for drug discovery. We also provide recommendations on strategies for implementing various assay types to select high quality leads for drug development.
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Affiliation(s)
- Scott A. Busby
- Novartis Institutes for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, Massachusetts, United States
| | - Seth Carbonneau
- Novartis Institutes for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, Massachusetts, United States
| | - John Concannon
- Novartis Institutes for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, Massachusetts, United States
| | | | - YounKyoung Lee
- Novartis Institutes for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, Massachusetts, United States
| | - Shin Numao
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Nicole Renaud
- Novartis Institutes for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, Massachusetts, United States
| | - Thomas M. Smith
- Novartis Institutes for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, Massachusetts, United States
| | - Douglas S. Auld
- Novartis Institutes for Biomedical Research, Chemical Biology and Therapeutics, Cambridge, Massachusetts, United States
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16
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Haniff HS, Knerr L, Chen JL, Disney MD, Lightfoot HL. Target-Directed Approaches for Screening Small Molecules against RNA Targets. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2020; 25:869-894. [PMID: 32419578 PMCID: PMC7442623 DOI: 10.1177/2472555220922802] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
RNA molecules have a variety of cellular functions that can drive disease pathologies. They are without a doubt one of the most intriguing yet controversial small-molecule drug targets. The ability to widely target RNA with small molecules could be revolutionary, once the right tools, assays, and targets are selected, thereby defining which biomolecules are targetable and what constitutes drug-like small molecules. Indeed, approaches developed over the past 5-10 years have changed the face of small molecule-RNA targeting by addressing historic concerns regarding affinity, selectivity, and structural dynamics. Presently, selective RNA-protein complex stabilizing drugs such as branaplam and risdiplam are in clinical trials for the modulation of SMN2 splicing, compounds identified from phenotypic screens with serendipitous outcomes. Fully developing RNA as a druggable target will require a target engagement-driven approach, and evolving chemical collections will be important for the industrial development of this class of target. In this review we discuss target-directed approaches that can be used to identify RNA-binding compounds and the chemical knowledge we have today of small-molecule RNA binders.
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Affiliation(s)
- Hafeez S. Haniff
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, USA
| | - Laurent Knerr
- Medicinal Chemistry, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Jonathan L. Chen
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, USA
| | - Matthew D. Disney
- Department of Chemistry, The Scripps Research Institute, Jupiter, FL, USA
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17
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Benhamou RI, Abe M, Choudhary S, Meyer SM, Angelbello AJ, Disney MD. Optimization of the Linker Domain in a Dimeric Compound that Degrades an r(CUG) Repeat Expansion in Cells. J Med Chem 2020; 63:7827-7839. [PMID: 32657583 DOI: 10.1021/acs.jmedchem.0c00558] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
RNA repeat expansions are responsible for more than 30 incurable diseases. Among them is myotonic dystrophy type 1 (DM1), the most common form of adult on-set muscular dystrophy. DM1 is caused by an r(CUG) repeat expansion [r(CUG)exp] located in the 3' untranslated region (UTR) of the dystrophia myotonica protein kinase gene. This repeat expansion is highly structured, forming a periodic array of 5'CUG/3'GUC internal loop motifs. We therefore designed dimeric compounds that simultaneously bind two of these motifs by connecting two RNA-binding modules with peptoid linkers of different geometries and lengths. The optimal linker contains two proline residues and enhances compound affinity. Equipping this molecule with a bleomycin A5 cleaving module converts the simple binding compound into a potent allele-selective cleaver of r(CUG)exp. This study shows that the linker in modularly assembled ligands targeting RNA can be optimized to afford potent biological activity.
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Affiliation(s)
- Raphael I Benhamou
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Masahito Abe
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Shruti Choudhary
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Samantha M Meyer
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Alicia J Angelbello
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
| | - Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United States
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18
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Benhamou RI, Angelbello AJ, Wang ET, Disney MD. A Toxic RNA Catalyzes the Cellular Synthesis of Its Own Inhibitor, Shunting It to Endogenous Decay Pathways. Cell Chem Biol 2020; 27:223-231.e4. [PMID: 31981476 DOI: 10.1016/j.chembiol.2020.01.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 11/22/2019] [Accepted: 01/03/2020] [Indexed: 12/12/2022]
Abstract
Myotonic dystrophy type 2 (DM2) is a genetically defined disease caused by a toxic expanded repeat of r(CCUG) [r(CCUG)exp], harbored in intron 1 of CCHC-type zinc-finger nucleic acid binding protein (CNBP) pre-mRNA. This r(CCUG)exp causes toxicity via a gain-of-function mechanism, resulting in three pathological hallmarks: aggregation into nuclear foci; sequestration of muscleblind-like-1 (MBNL1) protein, leading to splicing defects; and retention of CNBP intron 1. We studied two types of small molecules with different modes of action, ones that simply bind and ones that are templated by r(CCUG)exp in cells, i.e., the RNA synthesizes its own drug. Indeed, our studies completed in DM2 patient-derived fibroblasts showed that the compounds disrupt the r(CCUG)exp-MBNL1 complex, reduce intron retention, subjecting the liberated intronic r(CCUG)exp to native decay pathways, and rescue other DM2-associated cellular defects. Importantly, this study shows that small molecules can modulate RNA biology by shunting toxic transcripts toward native decay pathways.
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Affiliation(s)
- Raphael I Benhamou
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Alicia J Angelbello
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Eric T Wang
- Department of Molecular Genetics & Microbiology, Center for NeuroGenetics, UF Genetics Institute, University of Florida, 2033 Mowry Road, Gainesville, FL 32610, USA
| | - Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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19
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Orthogonal assays for the identification of inhibitors of the single-stranded nucleic acid binding protein YB-1. Acta Pharm Sin B 2019; 9:997-1007. [PMID: 31649849 PMCID: PMC6804448 DOI: 10.1016/j.apsb.2018.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 12/26/2018] [Accepted: 12/29/2018] [Indexed: 02/01/2023] Open
Abstract
We have previously shown that high expression of the nucleic acid binding factor YB-1 is strongly associated with poor prognosis in a variety of cancer types. The 3-dimensional protein structure of YB-1 has yet to be determined and its role in transcriptional regulation remains elusive. Drug targeting of transcription factors is often thought to be difficult and there are very few published high-throughput screening approaches. YB-1 predominantly binds to single-stranded nucleic acids, adding further difficulty to drug discovery. Therefore, we have developed two novel screening assays to detect compounds that interfere with the transcriptional activation properties of YB-1, both of which may be generalizable to screen for inhibitors of other nucleic acid binding molecules. The first approach is a cell-based luciferase reporter gene assay that measures the level of activation of a fragment of the E2F1 promoter by YB-1. The second approach is a novel application of the AlphaScreen system, to detect interference of YB-1 interaction with a single-stranded DNA binding site. These complementary assays examine YB-1 binding to two discrete nucleic acid sequences using two different luminescent signal outputs and were employed sequentially to screen 7360 small molecule compounds leading to the identification of three putative YB-1 inhibitors.
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Key Words
- AlphaScreen
- CSD, cold shock domain
- CTD, C-terminal domain
- Cancer
- DMSO, dimethylsulfoxide
- E2F1, E2F transcription factor 1
- EGR1, early growth response 1
- HTS, high-throughput screening
- Luciferase
- NTD, N-terminal domain
- Single-stranded DNA
- Transcription factor
- YB-1
- YB-1, Y-box binding protein-1
- YBX1, Y-box binding protein gene 1
- cDNA, complementary DNA
- dsDNA, double-stranded DNA
- shRNA, short-hairpin RNA
- siRNA, small-interfering RNA
- ssDNA, single-stranded DNA
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20
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Reddy K, Jenquin JR, Cleary JD, Berglund JA. Mitigating RNA Toxicity in Myotonic Dystrophy using Small Molecules. Int J Mol Sci 2019; 20:E4017. [PMID: 31426500 PMCID: PMC6720693 DOI: 10.3390/ijms20164017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 12/26/2022] Open
Abstract
This review, one in a series on myotonic dystrophy (DM), is focused on the development and potential use of small molecules as therapeutics for DM. The complex mechanisms and pathogenesis of DM are covered in the associated reviews. Here, we examine the various small molecule approaches taken to target the DNA, RNA, and proteins that contribute to disease onset and progression in myotonic dystrophy type 1 (DM1) and 2 (DM2).
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Affiliation(s)
- Kaalak Reddy
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA.
| | - Jana R Jenquin
- Center for NeuroGenetics and Biochemistry & Molecular Biology, University of Florida, Gainesville, FL 32608, USA
| | - John D Cleary
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA
| | - J Andrew Berglund
- The RNA Institute, University at Albany-SUNY, Albany, NY 12222, USA.
- Center for NeuroGenetics and Biochemistry & Molecular Biology, University of Florida, Gainesville, FL 32608, USA.
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21
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Taylor K, Sznajder LJ, Cywoniuk P, Thomas JD, Swanson MS, Sobczak K. MBNL splicing activity depends on RNA binding site structural context. Nucleic Acids Res 2019; 46:9119-9133. [PMID: 29955876 PMCID: PMC6158504 DOI: 10.1093/nar/gky565] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 06/16/2018] [Indexed: 02/02/2023] Open
Abstract
Muscleblind-like (MBNL) proteins are conserved RNA-binding factors involved in alternative splicing (AS) regulation during development. While AS is controlled by distribution of MBNL paralogs and isoforms, the affinity of these proteins for specific RNA-binding regions and their location within transcripts, it is currently unclear how RNA structure impacts MBNL-mediated AS regulation. Here, we defined the RNA structural determinants affecting MBNL-dependent AS activity using both cellular and biochemical assays. While enhanced inclusion of MBNL-regulated alternative exons is controlled by the arrangement and number of MBNL binding sites within unstructured RNA, when these sites are embedded in a RNA hairpin MBNL binds preferentially to one side of stem region. Surprisingly, binding of MBNL proteins to RNA targets did not entirely correlate with AS efficiency. Moreover, comparison of MBNL proteins revealed structure-dependent competitive behavior between the paralogs. Our results showed that the structure of targeted RNAs is a prevalent component of the mechanism of alternative splicing regulation by MBNLs.
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Affiliation(s)
- Katarzyna Taylor
- Laboratory of Gene Therapy, Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - Lukasz J Sznajder
- Center for NeuroGenetics and the Genetics Institute, Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, 2033 Mowry Road, Gainesville, FL 32610, USA
| | - Piotr Cywoniuk
- Laboratory of Gene Therapy, Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
| | - James D Thomas
- Center for NeuroGenetics and the Genetics Institute, Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, 2033 Mowry Road, Gainesville, FL 32610, USA.,Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Maurice S Swanson
- Center for NeuroGenetics and the Genetics Institute, Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, 2033 Mowry Road, Gainesville, FL 32610, USA
| | - Krzysztof Sobczak
- Laboratory of Gene Therapy, Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland
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22
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Unveiling the druggable RNA targets and small molecule therapeutics. Bioorg Med Chem 2019; 27:2149-2165. [PMID: 30981606 PMCID: PMC7126819 DOI: 10.1016/j.bmc.2019.03.057] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 03/25/2019] [Accepted: 03/29/2019] [Indexed: 12/15/2022]
Abstract
The increasing appreciation for the crucial roles of RNAs in infectious and non-infectious human diseases makes them attractive therapeutic targets. Coding and non-coding RNAs frequently fold into complex conformations which, if effectively targeted, offer opportunities to therapeutically modulate numerous cellular processes, including those linked to undruggable protein targets. Despite the considerable skepticism as to whether RNAs can be targeted with small molecule therapeutics, overwhelming evidence suggests the challenges we are currently facing are not outside the realm of possibility. In this review, we highlight the most recent advances in molecular techniques that have sparked a revolution in understanding the RNA structure-to-function relationship. We bring attention to the application of these modern techniques to identify druggable RNA targets and to assess small molecule binding specificity. Finally, we discuss novel screening methodologies that support RNA drug discovery and present examples of therapeutically valuable RNA targets.
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23
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Disney MD. Targeting RNA with Small Molecules To Capture Opportunities at the Intersection of Chemistry, Biology, and Medicine. J Am Chem Soc 2019; 141:6776-6790. [PMID: 30896935 DOI: 10.1021/jacs.8b13419] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The biology of healthy and disease-affected cells is often mediated by RNA structures, desirable targets for small molecule chemical probes and lead medicines. Although structured regions are found throughout the transcriptome, some even with demonstrated functionality, human RNAs are considered recalcitrant to small molecule targeting. However, targeting structured regions with small molecules provides an important alternative to oligonucleotides that target sequence. In this Perspective, we describe challenges and progress in developing small molecules interacting with RNA (SMIRNAs) to capture their significant opportunities at the intersection of chemistry, biology, and medicine. Key to establishing a new paradigm in chemical biology and medicine is the development of methods to obtain, preferably by design, bioactive compounds that modulate RNA targets and companion methods that validate their direct effects in cells and pre-clinical models. While difficult, demonstration of direct target engagement in the complex cellular milieu, along with methods to establish modes of action, is required to push this field forward. We also describe frameworks for accelerated advancements in this burgeoning area, their implications, key new technologies for development of SMIRNAs, and milestones that have led to broader acceptance of RNA as a small molecule druggable target.
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Affiliation(s)
- Matthew D Disney
- Department of Chemistry , The Scripps Research Institute , Jupiter , Florida 33458 , United States
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24
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Qu J, Chen X, Sun YZ, Zhao Y, Cai SB, Ming Z, You ZH, Li JQ. In Silico Prediction of Small Molecule-miRNA Associations Based on the HeteSim Algorithm. MOLECULAR THERAPY-NUCLEIC ACIDS 2018; 14:274-286. [PMID: 30654189 PMCID: PMC6348698 DOI: 10.1016/j.omtn.2018.12.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/15/2018] [Accepted: 12/04/2018] [Indexed: 01/27/2023]
Abstract
Targeting microRNAs (miRNAs) with drug small molecules (SMs) is a new treatment method for many human complex diseases. Unsurprisingly, identification of potential miRNA-SM associations is helpful for pharmaceutical engineering and disease therapy in the field of medical research. In this paper, we developed a novel computational model of HeteSim-based inference for SM-miRNA Association prediction (HSSMMA) by implementing a path-based measurement method of HeteSim on a heterogeneous network combined with known miRNA-SM associations, integrated miRNA similarity, and integrated SM similarity. Through considering paths from an SM to a miRNA in the heterogeneous network, the model can capture the semantics information under each path and predict potential miRNA-SM associations based on all the considered paths. We performed global, miRNA-fixed local and SM-fixed local leave one out cross validation (LOOCV) as well as 5-fold cross validation based on the dataset of known miRNA-SM associations to evaluate the prediction performance of our approach. The results showed that HSSMMA gained the corresponding areas under the receiver operating characteristic (ROC) curve (AUCs) of 0.9913, 0.9902, 0.7989, and 0.9910 ± 0.0004 based on dataset 1 and AUCs of 0.7401, 0.8466, 0.6149, and 0.7451 ± 0.0054 based on dataset 2, respectively. In case studies, 2 of the top 10 and 13 of the top 50 predicted potential miRNA-SM associations were confirmed by published literature. We further implemented case studies to test whether HSSMMA was effective for new SMs without any known related miRNAs. The results from cross validation and case studies showed that HSSMMA could be a useful prediction tool for the identification of potential miRNA-SM associations.
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Affiliation(s)
- Jia Qu
- School of Information and Control Engineering, China University of Mining and Technology, Xuzhou 221116, China
| | - Xing Chen
- School of Information and Control Engineering, China University of Mining and Technology, Xuzhou 221116, China.
| | - Ya-Zhou Sun
- College of Computer Science and Software Engineering, Shenzhen University, Shenzhen 518060, China
| | - Yan Zhao
- School of Information and Control Engineering, China University of Mining and Technology, Xuzhou 221116, China
| | - Shu-Bin Cai
- College of Computer Science and Software Engineering, Shenzhen University, Shenzhen 518060, China
| | - Zhong Ming
- College of Computer Science and Software Engineering, Shenzhen University, Shenzhen 518060, China.
| | - Zhu-Hong You
- Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Science, Ürümqi 830011, China.
| | - Jian-Qiang Li
- College of Computer Science and Software Engineering, Shenzhen University, Shenzhen 518060, China
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25
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Wang ZF, Ursu A, Childs-Disney JL, Guertler R, Yang WY, Bernat V, Rzuczek SG, Fuerst R, Zhang YJ, Gendron TF, Yildirim I, Dwyer BG, Rice JE, Petrucelli L, Disney MD. The Hairpin Form of r(G 4C 2) exp in c9ALS/FTD Is Repeat-Associated Non-ATG Translated and a Target for Bioactive Small Molecules. Cell Chem Biol 2018; 26:179-190.e12. [PMID: 30503283 DOI: 10.1016/j.chembiol.2018.10.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 07/16/2018] [Accepted: 10/20/2018] [Indexed: 12/13/2022]
Abstract
The most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is an expanded G4C2 repeat [(G4C2)exp] in C9ORF72. ALS/FTD-associated toxicity has been traced to the RNA transcribed from the repeat expansion [r(G4C2)exp], which sequesters RNA-binding proteins (RBPs) and undergoes repeat-associated non-ATG (RAN) translation to generate toxic dipeptide repeats. Using in vitro and cell-based assays, we identified a small molecule (4) that selectively bound r(G4C2)exp, prevented sequestration of an RBP, and inhibited RAN translation. Indeed, biophysical characterization showed that 4 selectively bound the hairpin form of r(G4C2)exp, and nuclear magnetic resonance spectroscopy studies and molecular dynamics simulations defined this molecular recognition event. Cellular imaging revealed that 4 localized to r(G4C2)exp cytoplasmic foci, the putative sites of RAN translation. Collectively, these studies highlight that the hairpin structure of r(G4C2)exp is a therapeutically relevant target and small molecules that bind it can ameliorate c9ALS/FTD-associated toxicity.
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Affiliation(s)
- Zi-Fu Wang
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Andrei Ursu
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Jessica L Childs-Disney
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Rea Guertler
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Wang-Yong Yang
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Viachaslau Bernat
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Suzanne G Rzuczek
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Rita Fuerst
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Yong-Jie Zhang
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Tania F Gendron
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Ilyas Yildirim
- Department of Chemistry and Biochemistry, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Brendan G Dwyer
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Joseph E Rice
- Department of Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, 160 Frelinghuysen Road, Piscataway, NJ 08854, USA
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Matthew D Disney
- Departments of Chemistry and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA.
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26
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Rizvi NF, Howe JA, Nahvi A, Klein DJ, Fischmann TO, Kim HY, McCoy MA, Walker SS, Hruza A, Richards MP, Chamberlin C, Saradjian P, Butko MT, Mercado G, Burchard J, Strickland C, Dandliker PJ, Smith GF, Nickbarg EB. Discovery of Selective RNA-Binding Small Molecules by Affinity-Selection Mass Spectrometry. ACS Chem Biol 2018; 13:820-831. [PMID: 29412640 DOI: 10.1021/acschembio.7b01013] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recent advances in understanding the relevance of noncoding RNA (ncRNA) to disease have increased interest in drugging ncRNA with small molecules. The recent discovery of ribocil, a structurally distinct synthetic mimic of the natural ligand of the flavin mononucleotide (FMN) riboswitch, has revealed the potential chemical diversity of small molecules that target ncRNA. Affinity-selection mass spectrometry (AS-MS) is theoretically applicable to high-throughput screening (HTS) of small molecules binding to ncRNA. Here, we report the first application of the Automated Ligand Detection System (ALIS), an indirect AS-MS technique, for the selective detection of small molecule-ncRNA interactions, high-throughput screening against large unbiased small-molecule libraries, and identification and characterization of novel compounds (structurally distinct from both FMN and ribocil) that target the FMN riboswitch. Crystal structures reveal that different compounds induce various conformations of the FMN riboswitch, leading to different activity profiles. Our findings validate the ALIS platform for HTS screening for RNA-binding small molecules and further demonstrate that ncRNA can be broadly targeted by chemically diverse yet selective small molecules as therapeutics.
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Affiliation(s)
- Noreen F. Rizvi
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | - John A. Howe
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Ali Nahvi
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Daniel J. Klein
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | | | - Hai-Young Kim
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | - Mark A. McCoy
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Scott S. Walker
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Alan Hruza
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | | | - Chad Chamberlin
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | - Peter Saradjian
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | | | - Gabriel Mercado
- Biodesy, Inc., South San Francisco, California 94080, United States
| | - Julja Burchard
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
| | | | | | - Graham F. Smith
- Merck & Co., Inc., Boston, Massachusetts 02115, United States
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27
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RNA as a small molecule druggable target. Bioorg Med Chem Lett 2017; 27:5083-5088. [PMID: 29097169 DOI: 10.1016/j.bmcl.2017.10.052] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/11/2017] [Accepted: 10/22/2017] [Indexed: 12/20/2022]
Abstract
Small molecule drugs have readily been developed against many proteins in the human proteome, but RNA has remained an elusive target for drug discovery. Increasingly, we see that RNA, and to a lesser extent DNA elements, show a persistent tertiary structure responsible for many diverse and complex cellular functions. In this digest, we have summarized recent advances in screening approaches for RNA targets and outlined the discovery of novel, drug-like small molecules against RNA targets from various classes and therapeutic areas. The link of structure, function, and small-molecule Druggability validates now for the first time that RNA can be the targets of therapeutic agents.
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28
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Konieczny P, Selma-Soriano E, Rapisarda AS, Fernandez-Costa JM, Perez-Alonso M, Artero R. Myotonic dystrophy: candidate small molecule therapeutics. Drug Discov Today 2017; 22:1740-1748. [PMID: 28780071 DOI: 10.1016/j.drudis.2017.07.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/14/2017] [Accepted: 07/25/2017] [Indexed: 01/01/2023]
Abstract
Myotonic dystrophy type 1 (DM1) is a rare multisystemic neuromuscular disorder caused by expansion of CTG trinucleotide repeats in the noncoding region of the DMPK gene. Mutant DMPK transcripts are toxic and alter gene expression at several levels. Chiefly, the secondary structure formed by CUGs has a strong propensity to capture and retain proteins, like those of the muscleblind-like (MBNL) family. Sequestered MBNL proteins cannot then fulfill their normal functions. Many therapeutic approaches have been explored to reverse these pathological consequences. Here, we review the myriad of small molecules that have been proposed for DM1, including examples obtained from computational rational design, HTS, drug repurposing, and therapeutic gene modulation.
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Affiliation(s)
- Piotr Konieczny
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), Universitat de València, Valencia, Spain; Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain; Joint Unit Incliva-CIPF, Valencia, Spain
| | - Estela Selma-Soriano
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), Universitat de València, Valencia, Spain; Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain; Joint Unit Incliva-CIPF, Valencia, Spain
| | - Anna S Rapisarda
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), Universitat de València, Valencia, Spain; Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain; Joint Unit Incliva-CIPF, Valencia, Spain
| | - Juan M Fernandez-Costa
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), Universitat de València, Valencia, Spain; Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain; Joint Unit Incliva-CIPF, Valencia, Spain
| | - Manuel Perez-Alonso
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), Universitat de València, Valencia, Spain; Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain; Joint Unit Incliva-CIPF, Valencia, Spain
| | - Ruben Artero
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), Universitat de València, Valencia, Spain; Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain; Joint Unit Incliva-CIPF, Valencia, Spain.
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29
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González ÀL, Konieczny P, Llamusi B, Delgado-Pinar E, Borrell JI, Teixidó J, García-España E, Pérez-Alonso M, Estrada-Tejedor R, Artero R. In silico discovery of substituted pyrido[2,3-d]pyrimidines and pentamidine-like compounds with biological activity in myotonic dystrophy models. PLoS One 2017; 12:e0178931. [PMID: 28582438 PMCID: PMC5459475 DOI: 10.1371/journal.pone.0178931] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 05/22/2017] [Indexed: 12/24/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a rare multisystemic disorder associated with an expansion of CUG repeats in mutant DMPK (dystrophia myotonica protein kinase) transcripts; the main effect of these expansions is the induction of pre-mRNA splicing defects by sequestering muscleblind-like family proteins (e.g. MBNL1). Disruption of the CUG repeats and the MBNL1 protein complex has been established as the best therapeutic approach for DM1, hence two main strategies have been proposed: targeted degradation of mutant DMPK transcripts and the development of CUG-binding molecules that prevent MBNL1 sequestration. Herein, suitable CUG-binding small molecules were selected using in silico approaches such as scaffold analysis, similarity searching, and druggability analysis. We used polarization assays to confirm the CUG repeat binding in vitro for a number of candidate compounds, and went on to evaluate the biological activity of the two with the strongest affinity for CUG repeats (which we refer to as compounds 1–2 and 2–5) in DM1 mutant cells and Drosophila DM1 models with an impaired locomotion phenotype. In particular, 1–2 and 2–5 enhanced the levels of free MBNL1 in patient-derived myoblasts in vitro and greatly improved DM1 fly locomotion in climbing assays. This work provides new computational approaches for rational large-scale virtual screens of molecules that selectively recognize CUG structures. Moreover, it contributes valuable knowledge regarding two compounds with desirable biological activity in DM1 models.
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Affiliation(s)
- Àlex L. González
- Grup d’Enginyeria Molecular (GEM), Institut Químic de Sarrià (IQS)–Universitat Ramon Llull (URL), Barcelona, Catalonia, Spain
| | - Piotr Konieczny
- Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Valencia, Spain
- Incliva-CIPF joint unit, Valencia, Spain
| | - Beatriz Llamusi
- Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Valencia, Spain
- Incliva-CIPF joint unit, Valencia, Spain
| | | | - José I. Borrell
- Grup d’Enginyeria Molecular (GEM), Institut Químic de Sarrià (IQS)–Universitat Ramon Llull (URL), Barcelona, Catalonia, Spain
| | - Jordi Teixidó
- Grup d’Enginyeria Molecular (GEM), Institut Químic de Sarrià (IQS)–Universitat Ramon Llull (URL), Barcelona, Catalonia, Spain
| | | | - Manuel Pérez-Alonso
- Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Valencia, Spain
- Incliva-CIPF joint unit, Valencia, Spain
| | - Roger Estrada-Tejedor
- Grup d’Enginyeria Molecular (GEM), Institut Químic de Sarrià (IQS)–Universitat Ramon Llull (URL), Barcelona, Catalonia, Spain
- * E-mail:
| | - Rubén Artero
- Translational Genomics Group, Incliva Health Research Institute, Valencia, Spain
- Department of Genetics and Interdisciplinary Research Structure for Biotechnology and Biomedicine (ERI BIOTECMED), University of Valencia, Valencia, Spain
- Incliva-CIPF joint unit, Valencia, Spain
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30
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Precise small-molecule recognition of a toxic CUG RNA repeat expansion. Nat Chem Biol 2016; 13:188-193. [PMID: 27941760 DOI: 10.1038/nchembio.2251] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 10/03/2016] [Indexed: 01/10/2023]
Abstract
Excluding the ribosome and riboswitches, developing small molecules that selectively target RNA is a longstanding problem in chemical biology. A typical cellular RNA is difficult to target because it has little tertiary, but abundant secondary structure. We designed allele-selective compounds that target such an RNA, the toxic noncoding repeat expansion (r(CUG)exp) that causes myotonic dystrophy type 1 (DM1). We developed several strategies to generate allele-selective small molecules, including non-covalent binding, covalent binding, cleavage and on-site probe synthesis. Covalent binding and cleavage enabled target profiling in cells derived from individuals with DM1, showing precise recognition of r(CUG)exp. In the on-site probe synthesis approach, small molecules bound adjacent sites in r(CUG)exp and reacted to afford picomolar inhibitors via a proximity-based click reaction only in DM1-affected cells. We expanded this approach to image r(CUG)exp in its natural context.
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31
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Roos M, Pradère U, Ngondo RP, Behera A, Allegrini S, Civenni G, Zagalak JA, Marchand JR, Menzi M, Towbin H, Scheuermann J, Neri D, Caflisch A, Catapano CV, Ciaudo C, Hall J. A Small-Molecule Inhibitor of Lin28. ACS Chem Biol 2016; 11:2773-2781. [PMID: 27548809 DOI: 10.1021/acschembio.6b00232] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
New discoveries in RNA biology underscore a need for chemical tools to clarify their roles in pathophysiological mechanisms. In certain cancers, synthesis of the let-7 microRNA tumor suppressor is blocked by an RNA binding protein (RBP) Lin28, which docks onto a conserved sequence in let-7 precursor RNA molecules and prevents their maturation. Thus, the Lin28/let-7 interaction might be an attractive drug target, if not for the well-known difficulty in targeting RNA-protein interactions with drugs. Here, we describe a protein/RNA FRET assay using a GFP-Lin28 donor and a black-hole quencher (BHQ)-labeled let-7 acceptor, a fluorescent protein/quencher combination which is rarely used in screening despite favorable spectral properties. We tested 16 000 molecules and identified N-methyl-N-[3-(3-methyl[1,2,4]triazolo[4,3-b]pyridazin-6-yl)phenyl]acetamide, which blocked the Lin28/let-7 interaction, rescued let-7 processing and function in Lin28-expressing cancer cells, induced differentiation of mouse embryonic stem cells, and reduced tumor-sphere formation by 22Rv1 and Huh7 cells. A biotinylated derivative captured Lin28 from cell lysates consistent with an on-target mechanism in cells, though the compound also showed some activity against bromodomains in selectivity assays. The Lin28/let-7 axis is presently of high interest not only for its role as a bistable switch in stem-cell biology but also because of its prominent roles in numerous diseases. We anticipate that much can be learned from the use of this first reported small molecule antagonist of Lin28, including the potential of the Lin28/let-7 interaction as a new drug target for selected cancers. Furthermore, this approach to assay development may be used to identify antagonists of other RBP/RNA interactions suspected to be operative in pathophysiological mechanisms.
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Affiliation(s)
- Martina Roos
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Ugo Pradère
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Richard P. Ngondo
- Institute
of Molecular Health Sciences, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Alok Behera
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Sara Allegrini
- Institute
of Oncology Research, Oncology Institute of Southern Switzerland, 6500 Bellinzona, Switzerland
| | - Gianluca Civenni
- Institute
of Oncology Research, Oncology Institute of Southern Switzerland, 6500 Bellinzona, Switzerland
| | - Julian A. Zagalak
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Jean-Rémy Marchand
- Department
of Biochemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Mirjam Menzi
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Harry Towbin
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Jörg Scheuermann
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Dario Neri
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Amedeo Caflisch
- Department
of Biochemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Carlo V. Catapano
- Institute
of Oncology Research, Oncology Institute of Southern Switzerland, 6500 Bellinzona, Switzerland
| | - Constance Ciaudo
- Institute
of Molecular Health Sciences, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Jonathan Hall
- Institute
of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
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32
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Development of pharmacophore models for small molecules targeting RNA: Application to the RNA repeat expansion in myotonic dystrophy type 1. Bioorg Med Chem Lett 2016; 26:5792-5796. [PMID: 27839685 DOI: 10.1016/j.bmcl.2016.10.037] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/07/2016] [Accepted: 10/12/2016] [Indexed: 01/29/2023]
Abstract
RNA is an important drug target, but current approaches to identify bioactive small molecules have been engineered primarily for protein targets. Moreover, the identification of small molecules that bind a specific RNA target with sufficient potency remains a challenge. Computer-aided drug design (CADD) and, in particular, ligand-based drug design provide a myriad of tools to identify rapidly new chemical entities for modulating a target based on previous knowledge of active compounds without relying on a ligand complex. Herein we describe pharmacophore virtual screening based on previously reported active molecules that target the toxic RNA that causes myotonic dystrophy type 1 (DM1). DM1-associated defects are caused by sequestration of muscleblind-like 1 protein (MBNL1), an alternative splicing regulator, by expanded CUG repeats (r(CUG)exp). Several small molecules have been found to disrupt the MBNL1-r(CUG)exp complex, ameliorating DM1 defects. Our pharmacophore model identified a number of potential lead compounds from which we selected 11 compounds to evaluate. Of the 11 compounds, several improved DM1 defects both in vitro and in cells.
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33
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Sznajder ŁJ, Michalak M, Taylor K, Cywoniuk P, Kabza M, Wojtkowiak-Szlachcic A, Matłoka M, Konieczny P, Sobczak K. Mechanistic determinants of MBNL activity. Nucleic Acids Res 2016; 44:10326-10342. [PMID: 27733504 PMCID: PMC5137450 DOI: 10.1093/nar/gkw915] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 10/05/2016] [Indexed: 11/13/2022] Open
Abstract
Muscleblind-like (MBNL) proteins are critical RNA processing factors in development. MBNL activity is disrupted in the neuromuscular disease myotonic dystrophy type 1 (DM1), due to the instability of a non-coding microsatellite in the DMPK gene and the expression of CUG expansion (CUGexp) RNAs. Pathogenic interactions between MBNL and CUGexp RNA lead to the formation of nuclear complexes termed foci and prevent MBNL function in pre-mRNA processing. The existence of multiple MBNL genes, as well as multiple protein isoforms, raises the question of whether different MBNL proteins possess unique or redundant functions. To address this question, we coexpressed three MBNL paralogs in cells at equivalent levels and characterized both specific and redundant roles of these proteins in alternative splicing and RNA foci dynamics. When coexpressed in the same cells, MBNL1, MBNL2 and MBNL3 bind the same RNA motifs with different affinities. While MBNL1 demonstrated the highest splicing activity, MBNL3 showed the lowest. When forming RNA foci, MBNL1 is the most mobile paralog, while MBNL3 is rather static and the most densely packed on CUGexp RNA. Therefore, our results demonstrate that MBNL paralogs and gene-specific isoforms possess inherent functional differences, an outcome that could be enlisted to improve therapeutic strategies for DM1.
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Affiliation(s)
- Łukasz J Sznajder
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Michał Michalak
- Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Katarzyna Taylor
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Piotr Cywoniuk
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Michał Kabza
- Department of Bioinformatics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Agnieszka Wojtkowiak-Szlachcic
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Magdalena Matłoka
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Patryk Konieczny
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Krzysztof Sobczak
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
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34
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Connelly CM, Moon MH, Schneekloth JS. The Emerging Role of RNA as a Therapeutic Target for Small Molecules. Cell Chem Biol 2016; 23:1077-1090. [PMID: 27593111 PMCID: PMC5064864 DOI: 10.1016/j.chembiol.2016.05.021] [Citation(s) in RCA: 211] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/07/2016] [Accepted: 05/18/2016] [Indexed: 01/09/2023]
Abstract
Recent advances in understanding different RNAs and unique features of their biology have revealed a wealth of information. However, approaches to identify small molecules that target these newly discovered regulatory elements have been lacking. The application of new biochemical screening and design-based technologies, coupled with a resurgence of interest in phenotypic screening, has resulted in several compelling successes in targeting RNA. A number of recent advances suggest that achieving the long-standing goal of developing drug-like, biologically active small molecules that target RNA is possible. This review highlights advances and successes in approaches to targeting RNA with diverse small molecules, and the potential for these technologies to pave the way to new types of RNA-targeted therapeutics.
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Affiliation(s)
- Colleen M Connelly
- Chemical Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Michelle H Moon
- Chemical Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - John S Schneekloth
- Chemical Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA.
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35
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Herrendorff R, Faleschini MT, Stiefvater A, Erne B, Wiktorowicz T, Kern F, Hamburger M, Potterat O, Kinter J, Sinnreich M. Identification of Plant-derived Alkaloids with Therapeutic Potential for Myotonic Dystrophy Type I. J Biol Chem 2016; 291:17165-77. [PMID: 27298317 DOI: 10.1074/jbc.m115.710616] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Indexed: 11/06/2022] Open
Abstract
Myotonic dystrophy type I (DM1) is a disabling neuromuscular disease with no causal treatment available. This disease is caused by expanded CTG trinucleotide repeats in the 3' UTR of the dystrophia myotonica protein kinase gene. On the RNA level, expanded (CUG)n repeats form hairpin structures that sequester splicing factors such as muscleblind-like 1 (MBNL1). Lack of available MBNL1 leads to misregulated alternative splicing of many target pre-mRNAs, leading to the multisystemic symptoms in DM1. Many studies aiming to identify small molecules that target the (CUG)n-MBNL1 complex focused on synthetic molecules. In an effort to identify new small molecules that liberate sequestered MBNL1 from (CUG)n RNA, we focused specifically on small molecules of natural origin. Natural products remain an important source for drugs and play a significant role in providing novel leads and pharmacophores for medicinal chemistry. In a new DM1 mechanism-based biochemical assay, we screened a collection of isolated natural compounds and a library of over 2100 extracts from plants and fungal strains. HPLC-based activity profiling in combination with spectroscopic methods were used to identify the active principles in the extracts. The bioactivity of the identified compounds was investigated in a human cell model and in a mouse model of DM1. We identified several alkaloids, including the β-carboline harmine and the isoquinoline berberine, that ameliorated certain aspects of the DM1 pathology in these models. Alkaloids as a compound class may have potential for drug discovery in other RNA-mediated diseases.
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Affiliation(s)
- Ruben Herrendorff
- From the Neuromuscular Research Group, Departments of Neurology and Biomedicine, University Hospital Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland and
| | - Maria Teresa Faleschini
- the Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Adeline Stiefvater
- From the Neuromuscular Research Group, Departments of Neurology and Biomedicine, University Hospital Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland and
| | - Beat Erne
- From the Neuromuscular Research Group, Departments of Neurology and Biomedicine, University Hospital Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland and
| | - Tatiana Wiktorowicz
- From the Neuromuscular Research Group, Departments of Neurology and Biomedicine, University Hospital Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland and
| | - Frances Kern
- From the Neuromuscular Research Group, Departments of Neurology and Biomedicine, University Hospital Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland and
| | - Matthias Hamburger
- the Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Olivier Potterat
- the Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Jochen Kinter
- From the Neuromuscular Research Group, Departments of Neurology and Biomedicine, University Hospital Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland and
| | - Michael Sinnreich
- From the Neuromuscular Research Group, Departments of Neurology and Biomedicine, University Hospital Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland and
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36
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Yasgar A, Jadhav A, Simeonov A, Coussens NP. AlphaScreen-Based Assays: Ultra-High-Throughput Screening for Small-Molecule Inhibitors of Challenging Enzymes and Protein-Protein Interactions. Methods Mol Biol 2016; 1439:77-98. [PMID: 27316989 DOI: 10.1007/978-1-4939-3673-1_5] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
AlphaScreen technology has been routinely utilized in high-throughput screening assays to quantify analyte accumulation or depletion, bimolecular interactions, and post-translational modifications. The high signal-to-background, dynamic range, and sensitivity associated with AlphaScreens as well as the homogenous assay format and reagent stability make the technology particularly well suited for high-throughput screening applications. Here, we describe the development of AlphaScreen assays to identify small-molecule inhibitors of enzymes and protein-protein interactions using the highly miniaturized 1536-well format. The subsequent implementation of counter assays to identify false-positive compounds is also discussed.
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Affiliation(s)
- Adam Yasgar
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Building B, Rm. 1034E, Rockville, MD, 20850, USA
| | - Ajit Jadhav
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Building B, Rm. 1034E, Rockville, MD, 20850, USA
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Building B, Rm. 1034E, Rockville, MD, 20850, USA
| | - Nathan P Coussens
- National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Building B, Rm. 1034E, Rockville, MD, 20850, USA.
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37
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Rzuczek SG, Southern MR, Disney MD. Studying a Drug-like, RNA-Focused Small Molecule Library Identifies Compounds That Inhibit RNA Toxicity in Myotonic Dystrophy. ACS Chem Biol 2015; 10:2706-15. [PMID: 26414664 DOI: 10.1021/acschembio.5b00430] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There are many RNA targets in the transcriptome to which small molecule chemical probes and lead therapeutics are desired. However, identifying compounds that bind and modulate RNA function in cellulo is difficult. Although rational design approaches have been developed, they are still in their infancies and leave many RNAs "undruggable". In an effort to develop a small molecule library that is biased for binding RNA, we computationally identified "drug-like" compounds from screening collections that have favorable properties for binding RNA and for suitability as lead drugs. As proof-of-concept, this collection was screened for binding to and modulating the cellular dysfunction of the expanded repeating RNA (r(CUG)(exp)) that causes myotonic dystrophy type 1. Hit compounds bind the target in cellulo, as determined by the target identification approach Competitive Chemical Cross-Linking and Isolation by Pull-down (C-ChemCLIP), and selectively improve several disease-associated defects. The best compounds identified from our 320-member library are more potent in cellulo than compounds identified by high-throughput screening (HTS) campaigns against this RNA. Furthermore, the compound collection has a higher hit rate (9% compared to 0.01-3%), and the bioactive compounds identified are not charged; thus, RNA can be "drugged" with compounds that have favorable pharmacological properties. Finally, this RNA-focused small molecule library may serve as a useful starting point to identify lead "drug-like" chemical probes that affect the biological (dys)function of other RNA targets by direct target engagement.
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Affiliation(s)
- Suzanne G. Rzuczek
- Department
of Chemistry and ‡Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #3A1, Jupiter, Florida 33458, United States
| | - Mark R. Southern
- Department
of Chemistry and ‡Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #3A1, Jupiter, Florida 33458, United States
| | - Matthew D. Disney
- Department
of Chemistry and ‡Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #3A1, Jupiter, Florida 33458, United States
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38
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Donnelly CJ, Grima JC, Sattler R. Aberrant RNA homeostasis in amyotrophic lateral sclerosis: potential for new therapeutic targets? Neurodegener Dis Manag 2015; 4:417-37. [PMID: 25531686 DOI: 10.2217/nmt.14.36] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive motor neuron degeneration. The disease pathogenesis is multifaceted in that multiple cellular and molecular pathways have been identified as contributors to the disease progression. Consequently, numerous therapeutic targets have been pursued for clinical development, unfortunately with little success. The recent discovery of mutations in RNA modulating genes such as TARDBP/TDP-43, FUS/TLS or C9ORF72 changed our understanding of neurodegenerative mechanisms in ALS and introduced the role of dysfunctional RNA processing as a significant contributor to disease pathogenesis. This article discusses the latest findings on such RNA toxicity pathways in ALS and potential novel therapeutic approaches.
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Affiliation(s)
- Christopher J Donnelly
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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39
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Hoskins JW, Ofori LO, Chen CZ, Kumar A, Sobczak K, Nakamori M, Southall N, Patnaik S, Marugan JJ, Zheng W, Austin CP, Disney MD, Miller BL, Thornton CA. Lomofungin and dilomofungin: inhibitors of MBNL1-CUG RNA binding with distinct cellular effects. Nucleic Acids Res 2014; 42:6591-602. [PMID: 24799433 PMCID: PMC4041448 DOI: 10.1093/nar/gku275] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a dominantly inherited neuromuscular disorder resulting from expression of RNA containing an expanded CUG repeat (CUGexp). The pathogenic RNA is retained in nuclear foci. Poly-(CUG) binding proteins in the Muscleblind-like (MBNL) family are sequestered in foci, causing misregulated alternative splicing of specific pre-mRNAs. Inhibitors of MBNL1-CUGexp binding have been shown to restore splicing regulation and correct phenotypes in DM1 models. We therefore conducted a high-throughput screen to identify novel inhibitors of MBNL1-(CUG)12 binding. The most active compound was lomofungin, a natural antimicrobial agent. We found that lomofungin undergoes spontaneous dimerization in DMSO, producing dilomofungin, whose inhibition of MBNL1–(CUG)12 binding was 17-fold more potent than lomofungin itself. However, while dilomofungin displayed the desired binding characteristics in vitro, when applied to cells it produced a large increase of CUGexp RNA in nuclear foci, owing to reduced turnover of the CUGexp transcript. By comparison, the monomer did not induce CUGexp accumulation in cells and was more effective at rescuing a CUGexp-induced splicing defect. These results support the feasibility of high-throughput screens to identify compounds targeting toxic RNA, but also demonstrate that ligands for repetitive sequences may have unexpected effects on RNA decay.
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Affiliation(s)
- Jason W Hoskins
- Department of Neurology, University of Rochester, Rochester, NY 14642, USA
| | - Leslie O Ofori
- Department of Chemistry, University of Rochester, Rochester, NY 14642, USA
| | - Catherine Z Chen
- Department of Chemistry, Scripps Florida, Jupiter, FL 33458, USA
| | - Amit Kumar
- Department of Dermatology, University of Rochester, Rochester, NY 14642, USA
| | - Krzysztof Sobczak
- Department of Neurology, University of Rochester, Rochester, NY 14642, USA
| | - Masayuki Nakamori
- Department of Neurology, University of Rochester, Rochester, NY 14642, USA
| | - Noel Southall
- Department of Chemistry, Scripps Florida, Jupiter, FL 33458, USA
| | - Samarjit Patnaik
- Department of Chemistry, Scripps Florida, Jupiter, FL 33458, USA
| | - Juan J Marugan
- Department of Chemistry, Scripps Florida, Jupiter, FL 33458, USA
| | - Wei Zheng
- Department of Chemistry, Scripps Florida, Jupiter, FL 33458, USA
| | | | - Matthew D Disney
- Department of Dermatology, University of Rochester, Rochester, NY 14642, USA
| | - Benjamin L Miller
- Division of Pre-clinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892, USA
| | - Charles A Thornton
- Department of Neurology, University of Rochester, Rochester, NY 14642, USA
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40
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Induction and reversal of myotonic dystrophy type 1 pre-mRNA splicing defects by small molecules. Nat Commun 2013; 4:2044. [PMID: 23806903 PMCID: PMC3710115 DOI: 10.1038/ncomms3044] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 05/23/2013] [Indexed: 02/06/2023] Open
Abstract
The ability to control pre-mRNA splicing with small molecules could facilitate the development of therapeutics or cell-based circuits that control gene function. Myotonic dystrophy type 1 (DM1) is caused by the dysregulation of alternative pre-mRNA splicing due to sequestration of muscleblind-like 1 protein (MBNL1) by expanded, non-coding r(CUG) repeats (r(CUG)exp). Here we report two small molecules that induce or ameliorate alternative splicing dysregulation. The thiophene-containing small molecule (1) inhibits the interaction of MBNL1 with its natural pre-mRNA substrates. Compound (2), a substituted naphthyridine, binds r(CUG)exp and displaces MBNL1. Structural models show that 1 binds MBNL1 in the Zn-finger domain and that 2 interacts with UU loops in r(CUG)exp. This study provides a structural framework for small molecules that target MBNL1 by mimicking r(CUG)exp and shows that targeting MBNL1 causes dysregulation of alternative splicing, suggesting that MBNL1 is thus not a suitable therapeutic target for the treatment of DM1.
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41
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Ketley A, Chen CZ, Li X, Arya S, Robinson TE, Granados-Riveron J, Udosen I, Morris GE, Holt I, Furling D, Chaouch S, Haworth B, Southall N, Shinn P, Zheng W, Austin CP, Hayes CJ, Brook JD. High-content screening identifies small molecules that remove nuclear foci, affect MBNL distribution and CELF1 protein levels via a PKC-independent pathway in myotonic dystrophy cell lines. Hum Mol Genet 2013; 23:1551-62. [PMID: 24179176 PMCID: PMC3929092 DOI: 10.1093/hmg/ddt542] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Myotonic dystrophy (DM) is a multi-system neuromuscular disorder for which there is no treatment. We have developed a medium throughput phenotypic assay, based on the identification of nuclear foci in DM patient cell lines using in situ hybridization and high-content imaging to screen for potentially useful therapeutic compounds. A series of further assays based on molecular features of DM have also been employed. Two compounds that reduce and/or remove nuclear foci have been identified, Ro 31-8220 and chromomycin A3. Ro 31-8220 is a PKC inhibitor, previously shown to affect the hyperphosphorylation of CELF1 and ameliorate the cardiac phenotype in a DM1 mouse model. We show that the same compound eliminates nuclear foci, reduces MBNL1 protein in the nucleus, affects ATP2A1 alternative splicing and reduces steady-state levels of CELF1 protein. We demonstrate that this effect is independent of PKC activity and conclude that this compound may be acting on alternative kinase targets within DM pathophysiology. Understanding the activity profile for this compound is key for the development of targeted therapeutics in the treatment of DM.
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Affiliation(s)
- Ami Ketley
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
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42
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Rzuczek SG, Gao Y, Tang ZZ, Thornton CA, Kodadek T, Disney MD. Features of modularly assembled compounds that impart bioactivity against an RNA target. ACS Chem Biol 2013; 8:2312-21. [PMID: 24032410 DOI: 10.1021/cb400265y] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Transcriptomes provide a myriad of potential RNAs that could be the targets of therapeutics or chemical genetic probes of function. Cell-permeable small molecules, however, generally do not exploit these targets, owing to the difficulty in the design of high affinity, specific small molecules targeting RNA. As part of a general program to study RNA function using small molecules, we designed bioactive, modularly assembled small molecules that target the noncoding expanded RNA repeat that causes myotonic dystrophy type 1 (DM1), r(CUG)(exp). Herein, we present a rigorous study to elucidate features in modularly assembled compounds that afford bioactivity. Different modular assembly scaffolds were investigated, including polyamines, α-peptides, β-peptides, and peptide tertiary amides (PTAs). On the basis of activity as assessed by improvement of DM1-associated defects, stability against proteases, cellular permeability, and toxicity, we discovered that constrained backbones, namely, PTAs, are optimal. Notably, we determined that r(CUG)(exp) is the target of the optimal PTA in cellular models and that the optimal PTA improves DM1-associated defects in a mouse model. Biophysical analyses were employed to investigate potential sources of bioactivity. These investigations show that modularly assembled compounds have increased residence times on their targets and faster on rates than the RNA-binding modules from which they were derived. Moreover, they have faster on rates than the protein that binds r(CUG)(exp), the inactivation of which gives rise to DM1-associated defects. These studies provide information about features of small molecules that are programmable for targeting RNA, allowing for the facile optimization of therapeutics or chemical probes against other cellular RNA targets.
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Affiliation(s)
- Suzanne G. Rzuczek
- Department
of Chemistry, The Scripps Research Institute, Scripps Florida, 130
Scripps Way #3A1, Jupiter, Florida 33458, United States
| | - Yu Gao
- Department
of Chemistry, The Scripps Research Institute, Scripps Florida, 130
Scripps Way #3A1, Jupiter, Florida 33458, United States
| | - Zhen-Zhi Tang
- Department
of Neurology, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, United States
| | - Charles A. Thornton
- Department
of Neurology, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, United States
| | - Thomas Kodadek
- Department
of Chemistry, The Scripps Research Institute, Scripps Florida, 130
Scripps Way #3A1, Jupiter, Florida 33458, United States
| | - Matthew D. Disney
- Department
of Chemistry, The Scripps Research Institute, Scripps Florida, 130
Scripps Way #3A1, Jupiter, Florida 33458, United States
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Disney MD. Rational design of chemical genetic probes of RNA function and lead therapeutics targeting repeating transcripts. Drug Discov Today 2013; 18:1228-36. [PMID: 23939337 DOI: 10.1016/j.drudis.2013.07.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 07/26/2013] [Accepted: 07/31/2013] [Indexed: 02/06/2023]
Abstract
RNA is an important yet vastly underexploited target for small molecule chemical probes or lead therapeutics. Small molecules have been used successfully to modulate the function of the bacterial ribosome, viral RNAs and riboswitches. These RNAs are either highly expressed or can be targeted using substrate mimicry, a mainstay in the design of enzyme inhibitors. However, most cellular RNAs are neither highly expressed nor have a lead small molecule inhibitor, a significant challenge for drug discovery efforts. Herein, I describe the design of small molecules targeting expanded repeating transcripts that cause myotonic muscular dystrophy (DM). These test cases illustrate the challenges of designing small molecules that target RNA and the advantages of targeting repeating transcripts. Lastly, I discuss how small molecules might be more advantageous than oligonucleotides for targeting RNA.
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Affiliation(s)
- Matthew D Disney
- Department of Chemistry, The Scripps Research Institute, 130 Scripps Way #3A1, Jupiter, FL 33458, USA.
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44
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Guan L, Disney MD. Covalent Small-Molecule-RNA Complex Formation Enables Cellular Profiling of Small-Molecule-RNA Interactions. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201301639] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Guan L, Disney MD. Covalent small-molecule-RNA complex formation enables cellular profiling of small-molecule-RNA interactions. Angew Chem Int Ed Engl 2013; 52:10010-3. [PMID: 23913698 DOI: 10.1002/anie.201301639] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/02/2013] [Indexed: 01/13/2023]
Abstract
Won't let you go! A strategy is described to design small molecules that react with their cellular RNA targets. This approach not only improves the activity of compounds targeting RNA in cell culture by a factor of about 2500 but also enables cell-wide profiling of its RNA targets.
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Affiliation(s)
- Lirui Guan
- Department of Chemistry, The Scripps Research Institute, Scripps Florida, 130 Scripps Way, 3A1, Jupiter, FL 33458 (USA)
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46
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Childs-Disney JL, Parkesh R, Nakamori M, Thornton CA, Disney MD. Rational design of bioactive, modularly assembled aminoglycosides targeting the RNA that causes myotonic dystrophy type 1. ACS Chem Biol 2012; 7:1984-93. [PMID: 23130637 DOI: 10.1021/cb3001606] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Myotonic dystrophy type 1 (DM1) is caused when an expanded r(CUG) repeat (r(CUG)(exp)) binds the RNA splicing regulator muscleblind-like 1 protein (MBNL1) as well as other proteins. Previously, we reported that modularly assembled small molecules displaying a 6'-N-5-hexynoate kanamycin A RNA-binding module (K) on a peptoid backbone potently inhibit the binding of MBNL1 to r(CUG)(exp). However, these parent compounds are not appreciably active in cell-based models of DM1. The lack of potency was traced to suboptimal cellular permeability and localization. To improve these properties, second-generation compounds that are conjugated to a d-Arg(9) molecular transporter were synthesized. These modified compounds enter cells in higher concentrations than the parent compounds and are efficacious in cell-based DM1 model systems at low micromolar concentrations. In particular, they improve three defects that are the hallmarks of DM1: a translational defect due to nuclear retention of transcripts containing r(CUG)(exp); pre-mRNA splicing defects due to inactivation of MBNL1; and the formation of nuclear foci. The best compound in cell-based studies was tested in a mouse model of DM1. Modest improvement of pre-mRNA splicing defects was observed. These studies suggest that a modular assembly approach can afford bioactive compounds that target RNA.
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Affiliation(s)
- Jessica L. Childs-Disney
- Department
of Chemistry, Scripps Florida, 130 Scripps
Way, Jupiter, Florida
33458, United States
| | - Raman Parkesh
- Department
of Chemistry, Scripps Florida, 130 Scripps
Way, Jupiter, Florida
33458, United States
| | - Masayuki Nakamori
- Department
of Neurology, University of Rochester,
Rochester, New York 14642,
United States
| | - Charles A. Thornton
- Department
of Neurology, University of Rochester,
Rochester, New York 14642,
United States
| | - Matthew D. Disney
- Department
of Chemistry, Scripps Florida, 130 Scripps
Way, Jupiter, Florida
33458, United States
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47
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Chen CZ, Southall N, Xiao J, Marugan JJ, Ferrer M, Hu X, Jones RE, Feng S, Agoulnik IU, Zheng W, Agoulnik AI. Identification of small-molecule agonists of human relaxin family receptor 1 (RXFP1) by using a homogenous cell-based cAMP assay. ACTA ACUST UNITED AC 2012; 18:670-7. [PMID: 23212924 DOI: 10.1177/1087057112469406] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The relaxin hormone is involved in a variety of biological functions, including female reproduction and parturition, as well as regulation of cardiovascular, renal, pulmonary, and hepatic functions. It regulates extracellular matrix remodeling, cell invasiveness, proliferation, differentiation, and overall tissue homeostasis. The G protein-coupled receptor (GPCR) relaxin family receptor 1 (RXFP1) is a cognate relaxin receptor that mainly signals through cyclic AMP second messenger. Although agonists of the receptor could have a wide range of pharmacologic utility, until now there have been no reported small-molecule agonists for relaxin receptors. Here, we report the development of a quantitative high-throughput platform for an RXFP1 agonist screen based on homogenous cell-based HTRF cyclic AMP (cAMP) assay technology. Two small molecules of similar structure were independently identified from a screen of more than 365 677 compounds. Neither compound showed activity in a counterscreen with HEK293T cells transfected with an unrelated GPCR vasopressin 1b receptor. These small-molecule agonists also demonstrated selectivity against the RXFP2 receptor, providing a basis for future medicinal chemistry optimization of selective relaxin receptor agonists.
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Affiliation(s)
- Catherine Z Chen
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
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