| 1. |
- Andréasson, Måns, 1994-, et al.
(författare)
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Exploring the dispersion and electrostatic components in arene-arene interactions between ligands and G4 DNA to develop G4-ligands
- 2024
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Ingår i: Journal of Medicinal Chemistry. - : American Chemical Society (ACS). - 0022-2623 .- 1520-4804. ; 67:3, s. 2202-2219
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Tidskriftsartikel (refereegranskat)abstract
- G-Quadruplex (G4) DNA structures are important regulatory elements in central biological processes. Small molecules that selectively bind and stabilize G4 structures have therapeutic potential, and there are currently >1000 known G4 ligands. Despite this, only two G4 ligands ever made it to clinical trials. In this work, we synthesized several heterocyclic G4 ligands and studied their interactions with G4s (e.g., G4s from the c-MYC, c-KIT, and BCL-2 promoters) using biochemical assays. We further studied the effect of selected compounds on cell viability, the effect on the number of G4s in cells, and their pharmacokinetic properties. This identified potent G4 ligands with suitable properties and further revealed that the dispersion component in arene-arene interactions in combination with electron-deficient electrostatics is central for the ligand to bind with the G4 efficiently. The presented design strategy can be applied in the further development of G4-ligands with suitable properties to explore G4s as therapeutic targets.
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| 2. |
- Andréasson, Måns, 1994-
(författare)
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Redefining the essential molecular aspects that drive interactions between small molecules and G-quadruplex DNA
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- G-Quadruplex (G4) structures are secondary nucleic acid structures located in guanine-rich regions of DNA and RNA sequences, involved in gene regulation and cellular maintenance. Efforts to target G4s in a therapeutic setting are scarce, mainly due to vague details about the binding interactions between the ligands and the G4 structure combined with the lack of emphasis on drug-like properties early in the ligand development process. Furthermore, the ability to target specific G4 structures with small drug-like molecules remains a big challenge to overcome in the field. In this thesis, extensive organic synthesis developments coupled with computational-aided design and orthogonal in vitro assays has been used in tandem to reveal in-depth knowledge about ligand-to-G4 interactions. First, a macrocyclic approach was applied to design and discover novel G4 ligands which showed that macrocycles offer a solid foundation for ligand design. Next, computational tools to optimise the macrocyclic molecular conformation were used based on the macrocycles' abilities to stack on the G4 surface. In addition, macrocyclic, and non-macrocyclic ligands that bound G4 with high potency were shown to correlate with electron-deficient electrostatic potential (ESP) maps. The frequent inclusion of cationic residues in G4 ligands and their enhancement on ligand-to-G4 binding was, thereof, ascribed to their impact on the electrostatic character of the ligands' arene-arene interactions with the G4 surface, and not through direct electrostatic ionic interactions. In addition, the dispersion energetic component in the arene-arene interactions between the G4 ligand and the G4 was discovered to be paramount for ligand-to-G4 binding. The implementation of these descriptors in practice resulted in the discovery of potent G4 binders with adequate pharmacokinetic (PK) properties, accentuating the significance of understanding the molecular interactions between ligands and G4s in rational ligand design. Finally, a G4 ligand conjugated to an oligonucleotide was demonstrated as a modular approach to achieve selective binding of a ligand to a specific G4 structure.
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| 3. |
- Berner, Andreas, et al.
(författare)
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G4-ligand-conjugated oligonucleotides mediate selective binding and stabilization of individual G4 DNA structures
- 2023
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 146:10, s. 6926-6935
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Tidskriftsartikel (refereegranskat)abstract
- G-quadruplex (G4) DNA structures are prevalent secondary DNA structures implicated in fundamental cellular functions, such as replication and transcription. Furthermore, G4 structures are directly correlated to human diseases such as cancer and have been highlighted as promising therapeutic targets for their ability to regulate disease-causing genes, e.g., oncogenes. Small molecules that bind and stabilize these structures are thus valuable from a therapeutic perspective and helpful in studying the biological functions of the G4 structures. However, there are hundreds of thousands of G4 DNA motifs in the human genome, and a long-standing problem in the field is how to achieve specificity among these different G4 structures. Here, we developed a strategy to selectively target an individual G4 DNA structure. The strategy is based on a ligand that binds and stabilizes G4s without selectivity, conjugated to a guide oligonucleotide, that specifically directs the G4-Ligand-conjugated oligo (GL-O) to the single target G4 structure. By employing various biophysical and biochemical techniques, we show that the developed method enables the targeting of a unique, specific G4 structure without impacting other off-target G4 formations. Considering the vast amount of G4s in the human genome, this represents a promising strategy to study the presence and functions of individual G4s but may also hold potential as a future therapeutic modality.
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