Discovery of A G‐Quadruplex Unwinder That Unleashes the Translation of G‐Quadruplex‐Containing mRNA without Inducing DNA Damage

To explore the mechanisms and therapeutic strategies for G‐quadruplex (G4) mediated diseases, it is crucial to manipulate and intervene in intracellular G4 structures using small molecular tools. While hundreds of G4 stabilizers have been developed, there is a significant gap in the availability of G4 unwinding agents. Here, we propose a strategy to disrupt G‐quadruplexes by forming G−C hydrogen bonds with chemically modified cytidine trimers. We validated a good G4 unwinder, the 2′‐F cytidine trimer (2′‐F C3). 2′‐F C3 does not inhibit cell growth nor cause severe DNA damage at a concentration below 10 μM. Moreover, 2′‐F C3 does not affect gene transcription nor RNA splicing, while it significantly enhances the translation of G4‐containing mRNA and upregulates RNA splicing, RNA processing and cell cycle pathways. The discovery of this G4 unwinder provides a functional tool for the chemical modulation of G4s in living cells.