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.

中文翻译：

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azacryptands对高阶DNA结构的双重靶向诱导癌细胞中DNA连接介导的DNA损伤

DNA 本质上是动态的，并且会瞬时折叠成替代的高阶结构，例如 G-四链体 (G4) 和三向 DNA 连接 (TWJ)。G4s 和 TWJs 可以通过具有高化疗潜力的小分子（配体）来稳定，无论是作为独立的 DNA 损伤剂还是在合成致死策略中组合。虽然以前的方法声称使用特异性靶向 G4 或 TWJ 的配体，但我们在此报告了一种新方法，其中在体外靶向 TWJ 和 G4 的配体表现出不同于 G4 配体的细胞效应，并且归因于 TWJ 靶向。通过一组体外方法和理论模拟研究了这些新的双 TWJ-/G4-配体的 DNA 结合模式，并通过广泛的基于细胞的试验研究了它们的细胞特性。我们在这里展示了 TWJ-/G4-配体的细胞毒活性被 DNA 损伤反应 (DDR) 和 DNA 拓扑异构酶 2 (TOP2) 所减轻，使其不同于典型的 G4-配体，并暗示 TWJ 在细胞中的关键作用。我们设计并使用了一种可点击的配体 TrisNP-α，以提供对细胞中 TWJ 格局及其对联合治疗的调节的独特见解。利用这些丰富的数据来设计一种有效的合成杀伤策略，将双配体与临床相关的 DDR 抑制剂相结合。为细胞中 TWJ 的景观及其对联合治疗的调节提供独特的见解。利用这些丰富的数据来设计一种有效的合成杀伤策略，将双配体与临床相关的 DDR 抑制剂相结合。为细胞中 TWJ 的景观及其对联合治疗的调节提供独特的见解。利用这些丰富的数据来设计一种有效的合成杀伤策略，将双配体与临床相关的 DDR 抑制剂相结合。