Attenuation of c-Myc expression in breast cancer by hesperidin-mediated stabilization of its promoter proximal G quadruplex region

Abstract

Hesperidin, a citrus flavanone, demonstrates significant potential as an anticancer agent by targeting the c-Myc G-quadruplex (G4) silencer element (Pu-27), a key epigenetic regulator of c-Myc expression. Molecular docking analysis revealed a strong interaction with Pu-27 (binding energy: −48.344 kcal/mol), forming hydrogen bonds across five critical regions. This interaction stabilized the G4 structure, as confirmed by increased ellipticity, higher melting temperature, and enhanced nanostructure formation. In functional assays, Hesperidin selectively inhibited the viability of MDA-MB-231 breast cancer cells while sparing normal cells. It significantly reduced clonogenic potential, migration, and c-Myc expression, indicating its role in suppressing oncogenic pathways. Moreover, Hesperidin effectively reduced primer dimer formation in the PCR stop assay and decreased mTFP expression in the mTFP reporter assay, further supporting its specificity for G4 stabilization. Preclinical studies demonstrated that Hesperidin treatment led to a marked reduction in tumor volume with minimal systemic toxicity, highlighting its therapeutic potential. These findings establish Hesperidin as a promising small-molecule stabilizer of the c-Myc G4 silencer, offering a targeted strategy for breast cancer therapy. By directly modulating c-Myc expression, hesperidin holds promise for clinical translation as a selective and effective anticancer agent. © 2025