QN-302 demonstrates opposing effects between i-motif and G-quadruplex DNA structures in the promoter of the S100P gene
GC-rich sequences can form G-quadruplexes and i-motifs, which play crucial roles in regulating gene expression across various organisms. The experimental anticancer drug QN-302, known for its ability to destabilize G-quadruplexes, effectively down-regulates several cancer-related genes, particularly S100P. In this study, we demonstrate that QN-302 exerts significant opposing effects on i-motif DNA structures, positioning it as one of the most potent agents for destabilizing i-motifs to date. QN-302 targets both G-quadruplexes and i-motifs, leading to the down-regulation of multiple cancer-related genes. Notably, it shows remarkable synergistic effects when compared to other compounds that interact with G-quadruplexes and i-motifs. These findings highlight the importance of viewing G-quadruplex and i-motif DNA structures as an SOP1812 interconnected system in gene regulation.