Chimie pour la Reconnaissance moléculaire des acides nucléiques

Publications de l’équipe

Année de publication : 2021

Alice J-L Zheng, Aikaterini Thermou, Pedro Guixens Gallardo, Laurence Malbert-Colas, Chrysoula Daskalogianni, Nathan Vaudiau, Petter Brohagen, Anton Granzhan, Marc Blondel, Marie-Paule Teulade-Fichou, Rodrigo Prado Martins, Robin Fahraeus (2021 Nov 17)

The different activities of RNA G-quadruplex structures are controlled by flanking sequences.

Life science alliance : 5 : e202101232 : DOI : 10.26508/lsa.202101232 En savoir plus
Résumé

The role of G-quadruplex (G4) RNA structures is multifaceted and controversial. Here, we have used as a model the EBV-encoded EBNA1 and the Kaposi’s sarcoma-associated herpesvirus (KSHV)-encoded LANA1 mRNAs. We have compared the G4s in these two messages in terms of nucleolin binding, nuclear mRNA retention, and mRNA translation inhibition and their effects on immune evasion. The G4s in the message are clustered in one repeat sequence and the G4 ligand PhenDH2 prevents all G4-associated activities. The RNA G4s in the message take part in similar multiple mRNA functions but are spread throughout the message. The different G4 activities depend on flanking coding and non-coding sequences and, interestingly, can be separated individually. Together, the results illustrate the multifunctional, dynamic and context-dependent nature of G4 RNAs and highlight the possibility to develop ligands targeting specific RNA G4 functions. The data also suggest a common multifunctional repertoire of viral G4 RNA activities for immune evasion.

Replier
Jaime Franco Pinto, Alexandra Fillion, Patricia Duchambon, Sophie Bombard, Anton Granzhan (2021 Oct 9)

Acridine–O6-benzylguanine hybrids: Synthesis, DNA binding, MGMT inhibition and antiproliferative activity

European Journal of Medicinal Chemistry : 227 : 113909 : DOI : 10.1016/j.ejmech.2021.113909 En savoir plus
Résumé

Acridine–O6-benzylguanine hybrids
O6-Methylguanine-DNA-methyltransferase (MGMT) is a key DNA repair enzyme involved in chemoresistance to DNA-alkylating anti-cancer drugs such as Temozolomide (TMZ) through direct repair of drug-induced O6-methylguanine residues in DNA. MGMT substrate analogues, such as O6-benzylguanine (BG), efficiently inactivate MGMT in vitro and in cells; however, these drugs failed to reach the clinic due to adverse side effects. Here, we designed hybrid drugs combining a BG residue covalently linked to a DNA-interacting moiety (6-chloro-2-methoxy-9-aminoacridine). Specifically, two series of hybrids, encompassing three compounds each, were obtained by varying the position of the attachment point of BG (N9 of guanine vs. the benzyl group) and the length and nature of the linker. UV/vis absorption and fluorescence data indicate that all six hybrids adopt an intramolecularly stacked conformation in aqueous solutions in a wide range of temperatures. All hybrids interact with double-stranded DNA, as clearly evidenced by spectrophotometric titrations, without intercalation of the acridine ring and do not induce thermal stabilization of the duplex. All hybrids, as well as the reference DNA intercalator (6-chloro-2-methoxy-9-aminoacridine 8), irreversibly inhibit MGMT in vitro with variable efficiency, comparable to that of BG. In a multidrug-resistant glioblastoma cell line T98G, benzyl-linked hybrids 7a–c and the N9-linked hybrid 19b are moderately cytotoxic (GI50 ≥ 15 μM after 96 h), while N9-linked hybrids 19a and 19c are strongly cytotoxic (GI50 = 1–2 μM), similarly to acridine 8 (GI50 = 0.6 μM). Among all compounds, hybrids 19a and 19c, similarly to BG, display synergic cytotoxic effect upon co-treatment with subtoxic doses of TMZ, with combination index (CI) values as low as 0.2–0.3. In agreement with in vitro results, compound 19a inactivates cellular MGMT but, unlike BG, does not induce significant levels of DNA damage, either alone or in combination with TMZ, as indicated by the results of γH2AX immunostaining experiments. Instead, and unlike BG, compound 19a alone induces significant apoptosis of T98G cells, which is not further increased in a combination with TMZ. These results indicate that molecular mechanisms underlying the cytotoxicity of 19a and its combination with TMZ are distinct from that of BG. The strongly synergic properties of this combination represent an interesting therapeutic opportunity in treating TMZ-resistant cancers.

Replier
Joanna Zell, Katerina Duskova, Leïla Chouh, Madeleine Bossaert, Nicolas Chéron, Anton Granzhan, Sébastien Britton, David Monchaud (2021 Sep 22)

Dual targeting of higher-order DNA structures by azacryptands induces DNA junction-mediated DNA damage in cancer cells

Nucleic Acids Research : 49 : 10275–10288 : DOI : 10.1093/nar/gkab796 En savoir plus
Résumé

Dual targeting of higher-order

DNA is intrinsically dynamic and folds transiently into alternative higher-order structures such as G-quadruplexes (G4s) and three-way DNA junctions (TWJs). G4s and TWJs can be stabilised by small molecules (ligands) that have high chemotherapeutic potential, either as standalone DNA damaging agents or combined in synthetic lethality strategies. While previous approaches have claimed to use ligands that specifically target either G4s or TWJs, we report here on a new approach in which ligands targeting both TWJs and G4s in vitro demonstrate cellular effects distinct from that of G4 ligands, and attributable to TWJ targeting. The DNA binding modes of these new, dual TWJ-/G4-ligands were studied by a panel of in vitro methods and theoretical simulations, and their cellular properties by extensive cell-based assays. We show here that cytotoxic activity of TWJ-/G4-ligands is mitigated by the DNA damage response (DDR) and DNA topoisomerase 2 (TOP2), making them different from typical G4-ligands, and implying a pivotal role of TWJs in cells. We designed and used a clickable ligand, TrisNP-α, to provide unique insights into the TWJ landscape in cells and its modulation upon co-treatments. This wealth of data was exploited to design an efficient synthetic lethality strategy combining dual ligands with clinically relevant DDR inhibitors.

Replier
Aleksandr S. Oshchepkov, Oksana Reznichenko, Dan Xu, Boris S. Morozov, Anton Granzhan, Evgeny A. Kataev (2021 Sep 22)

Dye-functionalized Phosphate-binding Macrocycles: From Nucleotide to G-quadruplex Recognition and “turn-on” Fluorescence Sensing

Chemical Communications : 57 : 10632-10635 : DOI : 10.1039/D1CC04096K En savoir plus
Résumé

PBM-Dye strategy

A novel strategy to design “turn-on” fluorescent receptors for G-quadruplexes of DNA is presented, which relies on the connection of phosphate binding macrocycles (PBM) with naphthalimide dyes. A new PBM-dye family was synthesized and evaluated in terms of binding and detection of nucleotides and DNA G-quadruplexes of different topologies.

Replier
Jérémie Mitteaux, Pauline Lejault, Filip Wojciechowski, Alexandra Joubert, Julien Boudon, Nicolas Desbois, Claude P. Gros, Robert H. E. Hudson, Jean-Baptiste Boulé, Anton Granzhan, David Monchaud (2021 Aug 4)

Identifying G-Quadruplex-DNA-Disrupting Small Molecules

Journal of the American Chemical Society : 143 : 12567–12577 : DOI : 10.1021/jacs.1c04426 En savoir plus
Résumé

The quest for small molecules that strongly bind to G-quadruplex-DNA (G4), so-called G4 ligands, has invigorated the G4 research field from its very inception. Massive efforts have been invested to discover or rationally design G4 ligands, evaluate their G4-interacting properties in vitro through a series of now widely accepted and routinely implemented assays, and use them as innovative chemical biology tools to interrogate cellular networks that might involve G4s. In sharp contrast, only uncoordinated efforts aimed at developing small molecules that destabilize G4s have been invested to date, even though it is now recognized that such molecular tools would have tremendous application in neurobiology as many genetic and age-related diseases are caused by an overrepresentation of G4s. Herein, we report on our efforts to develop in vitro assays to reliably identify molecules able to destabilize G4s. This workflow comprises the newly designed G4-unfold assay, adapted from the G4-helicase assay implemented with Pif1, as well as a series of biophysical and biochemical techniques classically used to study G4/ligand interactions (CD, UV–vis, PAGE, and FRET-melting), and a qPCR stop assay, adapted from a Taq-based protocol recently used to identify G4s in the genomic DNA of Schizosaccharomyces pombe. This unique, multipronged approach leads to the characterization of a phenylpyrrolocytosine (PhpC)-based G-clamp analog as a prototype of G4-disrupting small molecule whose properties are validated through many different and complementary in vitro evaluations.

G4-unfold

Replier
Marc Lavigne, Olivier Helynck, Pascal Rigolet, Rofia Boudria-Souilah, Mireille Nowakowski, Bruno Baron, Sébastien Brülé, Sylviane Hoos, Bertrand Raynal, Lionel Guittat, Claire Beauvineau, Stéphane Petres, Anton Granzhan, Jean Guillon, Geneviève Pratviel, Marie-Paule Teulade-Fichou, Patrick England, Jean-Louis Mergny, Hélène Munier-Lehmann (2021 Jul 7)

SARS-CoV-2 Nsp3 unique domain SUD interacts with guanine quadruplexes and G4-ligands inhibit this interaction.

Nucleic Acids Research : 49 : 7695–7712 : DOI : 10.1093/nar/gkab571 En savoir plus
Résumé

The multidomain non-structural protein 3 (Nsp3) is the largest protein encoded by coronavirus (CoV) genomes and several regions of this protein are essential for viral replication. Of note, SARS-CoV Nsp3 contains a SARS-Unique Domain (SUD), which can bind Guanine-rich non-canonical nucleic acid structures called G-quadruplexes (G4) and is essential for SARS-CoV replication. We show herein that the SARS-CoV-2 Nsp3 protein also contains a SUD domain that interacts with G4s. Indeed, interactions between SUD proteins and both DNA and RNA G4s were evidenced by G4 pull-down, Surface Plasmon Resonance and Homogenous Time Resolved Fluorescence. These interactions can be disrupted by mutations that prevent oligonucleotides from folding into G4 structures and, interestingly, by molecules known as specific ligands of these G4s. Structural models for these interactions are proposed and reveal significant differences with the crystallographic and modeled 3D structures of the SARS-CoV SUD-NM/G4 interaction. Altogether, our results pave the way for further studies on the role of SUD/G4 interactions during SARS-CoV-2 replication and the use of inhibitors of these interactions as potential antiviral compounds.

Replier
Yu Luo, Anton Granzhan, Daniela Verga, Jean-Louis Mergny (2021 Apr 1)

FRET-MC: A fluorescence melting competition assay for studying G4 structures in vitro

Biopolymers : 112 : e23415 : DOI : 10.1002/bip.23415 En savoir plus
Résumé

G-quadruplexes (G4) play crucial roles in biology, analytical chemistry and nanotechnology. The stability of G4 structures is impacted by the number of G-quartets, the length and positions of loops, flanking motifs, as well as additional structural elements such as bulges, capping base pairs, or triads. Algorithms such as G4Hunter or Quadparser may predict if a given sequence is G4-prone by calculating a quadruplex propensity score; however, experimental validation is still required. We previously demonstrated that this validation is not always straightforward, and that a combination of techniques is often required to unambiguously establish whether a sequence forms a G-quadruplex or not. In this article, we adapted the well-known FRET-melting assay to characterize G4 in batch, where the sequence to be tested is added, as an unlabeled competitor, to a system composed of a dual-labeled probe (F21T) and a specific quadruplex ligand. PhenDC3 was preferred over TMPyP4 because of its better selectivity for G-quadruplexes. In this so-called FRET-MC (melting competition) assay, G4-forming competitors lead to a marked decrease of the ligand-induced stabilization effect (∆Tm), while non-specific competitors (e.g., single- or double-stranded sequences) have little effect. Sixty-five known sequences with different typical secondary structures were used to validate the assay, which was subsequently employed to assess eight novel sequences that were not previously characterized.

FRET-MC

Replier
Oksana Reznichenko, Anne Cucchiarini, Valérie Gabelica, Anton Granzhan (2021 Jan 14)

Quadruplex DNA-guided ligand selection from dynamic combinatorial libraries of acylhydrazones

Organic and Biomolecular Chemistry : 19 : 379-386 : DOI : 10.1039/D0OB01908A En savoir plus
Résumé

Dynamic combinatorial libraries of acylhydrazones were prepared from diacylhydrazides and several cationic or neutral aldehydes in the presence of 5-methoxyanthranilic acid catalyst. Pull-down experiments with magnetic beads functionalized with a G-quadruplex (G4)-forming oligonucleotide led to the identification of putative ligands, which were resynthesized or emulated by close structural analogues. G4-binding properties of novel derivatives were assessed by fluorimetric titrations, mass spectrometry and thermal denaturation experiments, giving evidence of strong binding (Kd < 10 nM) for two compounds.

Quadruplex DNA-guided ligand selection from dynamic combinatorial libraries of acylhydrazones

Replier

Année de publication : 2020

Anton Granzhan, Rodrigo Prado Martins, Robin Fåhraeus, Marc Blondel and Marie-Paule Teulade-Fichou (2020 Jun 30)

Quadruplex-interacting compounds for regulating the translation of the Epstein–Barr virus nuclear antigen 1 (EBNA1) mRNA: A new strategy to prevent and treat EBV-related cancers

Quadruplex Nucleic Acids As Targets For Medicinal Chemistry, Annual Reports in Medicinal Chemistry : Chap 8, 54 : 243-286 : DOI : 10.1016/bs.armc.2020.05.001 En savoir plus
Résumé

The Epstein–Barr (EBV) virus is linked to at least 1% of human cancers that include Burkitt’s and Hodgkin’s lymphomas, nasopharyngeal carcinoma, and 10% of gastric cancers. EBV is a latent virus that possesses a genome maintenance protein, EBNA1, which is both essential for the virus and highly antigenic. Hence, EBV has evolved a mechanism by which EBNA1 self-limits the translation of its own mRNA, thereby minimizing the production of EBNA1-derived antigenic peptides. Although not fully elucidated, this mechanism involves the Gly-Ala-rich (GAr) motif of EBNA1, encoded by a G-repeat-containing mRNA sequence able to form clusters of G-quadruplexes (G4s). This chapter summarizes recent significant advances in understanding this phenomenon. Mechanistic investigations based on yeast chemical genetics, cellular assays and in vitro experiments have shown that the host cell factor nucleolin (NCL) is involved in this limitation of EBNA1 translation through binding to the G4s of EBNA1 mRNA. This interaction can be disrupted by the benchmark G4-ligand PhenDC3 acting as a NCL competitor for binding to G4-RNA. Finally, exploration of the chemical space around PhenDC3 using combinatorial chemistry approach led to the generation of 20 compounds based on a bis(acylhydrazone) scaffold. Among these, two hits (PyDH2PhenDH2) exhibit optimized properties with regard to the disruption of NCL/G4 interaction in cells, along with lower cytotoxicity. Consequently, treatment by PyDH2 or PhenDH2 increases EBNA1 production and stimulates the GAr-restricted antigenic response. Altogether, this innovative concept of antigenic stimulation sets the basis for further identification of lead candidates that may become promising candidate drugs for treating EBV-related cancers

Replier
Michela Zuffo, Aurélie Gandolfini, Brahim Heddi, Anton Granzhan (2020 Apr 20)

Harnessing intrinsic fluorescence for typing of secondary structures of DNA

Nucleic Acids Research : 48 : e61 : DOI : 10.1093/nar/gkaa257 En savoir plus
Résumé

GA-NAR-2020

High-throughput investigation of structural diversity of nucleic acids is hampered by the lack of suitable label-free methods, combining fast and cheap experimental workflow with high information content. Here, we explore the use of intrinsic fluorescence emitted by nucleic acids for this scope. After a preliminary assessment of suitability of this phenomenon for tracking conformational changes of DNA, we examined steady-state emission spectra of an 89-membered set of oligonucleotides with reported conformation (G-quadruplexes (G4s), i-motifs, single- and double-strands) by means of multivariate analysis. Principal component analysis of emission spectra resulted in successful clustering of oligonucleotides into three corresponding conformational groups, without discrimination between single- and double-stranded structures. Linear discriminant analysis was exploited for the assessment of novel sequences, allowing the evaluation of their G4-forming propensity. Our method does not require any labeling agent or dye, avoiding the related bias, and can be utilized to screen novel sequences of interest in a high-throughput and cost-effective manner. In addition, we observed that left-handed (Z-) G4 structures were systematically more fluorescent than most other G4 structures, almost reaching the quantum yield of 5′-d[(G3T)3G3]-3′ (G3T, the most fluorescent G4 structure reported to date).

Replier

Année de publication : 2019

Katerina Duskova, Pauline Lejault, Élie Benchimol, Régis Guillot, Sébastien Britton, Anton Granzhan, David Monchaud (2019 Dec 13)

DNA junction ligands trigger DNA damage and are synthetic lethal with DNA repair inhibitors in cancer cells

Journal of the American Chemical Society : 142 : 424-435 : DOI : 10.1021/jacs.9b11150 En savoir plus
Résumé

Translocation of DNA and RNA polymerases along their duplex substrates results in DNA supercoiling. This torsional stress promotes the formation of plectonemic structures, including three-way DNA junction (TWJ), which can block DNA transactions and lead to DNA damage. While cells have evolved multiple mechanisms to prevent the accumulation of such structures, stabilizing TWJ through ad hoc ligands offer an opportunity to trigger DNA damage in cells with high level of transcription and replication, such as cancer cells. Here, we develop a series of azacryptand-based TWJ ligands, we thoroughly characterize their TWJ-interacting properties in vitro and demonstrate their capacity to trigger DNA damage in rapidly dividing human cancer cells. We also demonstrate that TWJ ligands are amenable to chemically induced synthetic lethality strategies upon association with inhibitors of DNA repair, thus paving the way towards innovative drug combinations to fight cancers.

DNA Junction Ligands Trigger DNA Damage

Replier
Michaela Krafcikova, Simon Dzatko, Coralie Caron, Anton Granzhan, Radovan Fiala, Tomas Loja, Marie-Paule Teulade-Fichou, Tomas Fessl, Robert Hänsel-Hertsch, Jean-Louis Mergny, Silvie Foldynova-Trantirkova, Lukas Trantirek (2019 Aug 9)

Monitoring DNA–Ligand Interactions in Living Human Cells Using NMR Spectroscopy

Journal of the American Chemical Society : 141 : 13281-13285 : DOI : 10.1021/jacs.9b03031 En savoir plus
Résumé

Studies on DNA–ligand interactions in the cellular environment are problematic due to the lack of suitable biophysical tools. To address this need, we developed an in-cell NMR-based approach for monitoring DNA–ligand interactions inside the nuclei of living human cells. Our method relies on the acquisition of NMR data from cells electroporated with preformed DNA–ligand complexes. The impact of the intracellular environment on the integrity of the complexes is assessed based on in-cell NMR signals from unbound and ligand-bound forms of a given DNA target. This technique was tested on complexes of two model DNA fragments and four ligands, namely, a representative DNA minor-groove binder (netropsin) and ligands binding DNA base-pairing defects (naphthalenophanes). In the latter case, we demonstrate that two of the three in vitro-validated ligands retain their ability to form stable interactions with their model target DNA in cellulo, whereas the third one loses this ability due to off-target interactions with genomic DNA and cellular metabolites. Collectively, our data suggest that direct evaluation of the behavior of drug-like molecules in the intracellular environment provides important insights into the development of DNA-binding ligands with desirable biological activity and minimal side effects resulting from off-target binding.

Monitoring DNA–Ligand Interactions in Living Human Cells Using NMR Spectroscopy

Replier
Xiao Xie, Michela Zuffo, Marie-Paule Teulade-Fichou, Anton Granzhan (2019 Aug 6)

Identification of optimal fluorescent probes for G-quadruplex nucleic acids through systematic exploration of mono- and distyryl dye libraries

Beilstein Journal of Organic Chemistry : 15 : 1872–1889 : DOI : 10.3762/bjoc.15.183 En savoir plus
Résumé

A library of 52 distyryl and 9 mono-styryl cationic dyes was synthesized and investigated with respect to their optical properties, propensity to aggregation in aqueous medium, and capacity to serve as fluorescence “light-up” probes for G-quadruplex (G4) DNA and RNA structures. Among the 61 compounds, 57 dyes showed preferential enhancement of fluorescence intensity in the presence of one or another G4-DNA or RNA structure, while no dye displayed preferential response to double-stranded DNA or single-stranded RNA analytes employed at equivalent nucleotide concentration. Thus, preferential fluorimetric response towards G4 structures appears to be a common feature of mono- and distyryl dyes, including long-known mono-styryl dyes used as mitochondrial probes or protein stains. However, the magnitude of the G4-induced “light-up” effect varies drastically, as a function of both the molecular structure of the dyes and the nature or topology of G4 analytes. Although our results do not allow to formulate comprehensive structure–properties relationships, we identified several structural motifs, such as indole- or pyrrole-substituted distyryl dyes, as well as simple mono-stryryl dyes such as DASPMI [2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide] or its 4-isomer, as optimal fluorescent light-up probes characterized by high fluorimetric response (I/I0 of up to 550-fold), excellent selectivity with respect to double-stranded DNA or single-stranded RNA controls, high quantum yield in the presence of G4 analytes (up to 0.32), large Stokes shift (up to 150 nm) and, in certain cases, structural selectivity with respect to one or another G4 folding topology. These dyes can be considered as promising G4-responsive sensors for in vitro or imaging applications. As a possible application, we implemented a simple two-dye fluorimetric assay allowing rapid topological classification of G4-DNA structures.

Identification of optimal fluorescent probes for G-quadruplex nucleic acids

Replier
Oksana Reznichenko, Alicia Quillévéré, Rodrigo Prado Martins, Nadège Loaëc, Hang Kang, María José Lista, Claire Beauvineau, Jorge González-García, Régis Guillot, Cécile Voisset, Chrysoula Daskalogianni, Robin Fåhraeus, Marie-Paule Teulade-Fichou, Marc Blondel, Anton Granzhan (2019 May 23)

Novel cationic bis(acylhydrazones) as modulators of Epstein–Barr virus immune evasion acting through disruption of interaction between nucleolin and G-quadruplexes of EBNA1 mRNA

European Journal of Medicinal Chemistry : 178 : 13-29 : DOI : 10.1016/j.ejmech.2019.05.042 En savoir plus
Résumé

EurJMedChem-2019-F

The oncogenic Epstein-Barr virus (EBV) evades the immune system through limiting the expression of its highly antigenic and essential genome maintenance protein, EBNA1, to the minimal level to ensure viral genome replication, thereby also minimizing the production of EBNA1-derived antigenic peptides. This regulation is based on inhibition of translation of the virally-encoded EBNA1 mRNA, and involves the interaction of host protein nucleolin (NCL) with G-quadruplex (G4) structures that form in the glycine–alanine repeat (GAr)-encoding sequence of the EBNA1 mRNA. Ligands that bind to these G4-RNA can prevent their interaction with NCL, leading to disinhibition of EBNA1 expression and antigen presentation, thereby interfering with the immune evasion of EBNA1 and therefore of EBV (M.J. Lista et al., Nature Commun., 2017, 8, 16043). In this work, we synthesized and studied a series of 20 cationic bis(acylhydrazone) derivatives designed as G4 ligands. The in vitro evaluation showed that most derivatives based on central pyridine (Py), naphthyridine (Naph) or phenanthroline (Phen) units were efficient G4 binders, in contrast to their pyrimidine (Pym) counterparts, which were poor G4 binders due to a significantly different molecular geometry. The influence of lateral heterocyclic units (N-substituted pyridinium or quinolinium residues) on G4-binding properties was also investigated. Two novel compounds, namely PyDH2 and PhenDH2, used at a 5 μM concentration, were able to significantly enhance EBNA1 expression in H1299 cells in a GAr-dependent manner, while being significantly less toxic than the prototype drug PhenDC3 (GI50 > 50 μM). Antigen presentation, RNA pull-down and proximity ligation assays confirmed that the effect of both drugs was related to the disruption of NCL–EBNA1 mRNA interaction and the subsequent promotion of GAr-restricted antigen presentation. Our work provides a novel modular scaffold for the development of G-quadruplex-targeting drugs acting through interference with G4–protein interaction.

Replier
Katerina Duskova, Jérémy Lamarche, Souheila Amor, Coralie Caron, Nicolas Queyriaux, Marie Gaschard, Marie-Jose Penouilh, Guillaume De Robillard, Dominique Delmas, Charles H Devillers, Anton Granzhan, Marie-Paule Teulade-Fichou, Murielle Chavarot-Kerlidou, Bruno Therrien, Sébastien Britton, David Monchaud (2019 Apr 3)

Identification of three-way DNA junction ligands through screening of chemical libraries and validation by complementary in vitro assays.

Journal of Medicinal Chemistry : 62 : 4456-4466 : DOI : 10.1021/acs.jmedchem.8b01978 En savoir plus
Résumé

The human genome is replete with repetitive DNA sequences that can fold into thermodynamically stable secondary structures such as hairpins and quadruplexes. Cellular enzymes exist to cope with these structures whose stable accumulation would result in DNA damage through interference with DNA transactions such as transcription and replication. Therefore, chemical stabilization of secondary DNA structures offers an attractive way to foster DNA transaction-associated damages to trigger cell death in proliferating cancer cells. While much emphasis has been recently given to DNA quadruplexes, we focused here on three-way DNA junctions (TWJ) and report on a strategy to identify TWJ-targeting agents through a combination of in vitro techniques (TWJ-Screen, PAGE, FRET-melting, ESI-MS, dialysis equilibrium and SRB assays). We designed a complete workflow and screened 1200 compounds to identify promising three-way DNA junction ligands selected on stringent criteria in terms of TWJ folding ability, affinity and selectivity.

GA-JMedChem-2019

Replier