Disrupting KRAS-AGO2 interaction: a dual-pronged strategy to sensitize chemo-immunotherapy in KRAS-mutated colorectal cancer.

KRAS mutations are among the most common genetic alterations in colorectal cancer (CRC) and are strongly linked to poor prognosis and therapeutic resistance. However, current treatments targeting KRAS-mutated CRC have shown limited clinical efficacy. Argonaute 2 (AGO2) is a critical component in microRNA (miRNA)-mediated gene silencing complex, which is involved in the maturation of miRNAs and the regulation of target genes. It has been reported that mutated KRAS can interact with AGO2 and impair its function, thereby amplifying the oncogenic potency of mutant KRAS and accelerating tumor progression. To explore the therapeutic implications of this interaction, we developed a peptide inhibitor and engineered peptide-gold nanoparticles (Au-pep) that specifically disrupted KRAS-AGO2 interaction, which dramatically attenuated the malignant phenotype of KRAS-mutated CRC cells. Mechanistically, Au-pep-mediated disruption of the KRAS-AGO2 complex led to partial restoration of the miRNA expression landscape, with let‑7c‑5p emerging as the most significantly up‑regulated effector. As a result, restored let-7c-5p caused a significant down-regulation of key oncogenic drivers (KRAS, c-Myc and Bcl2) to suppress the growth of KRAS-mutated CRC cells and induce their apoptosis. Furthermore, this miRNA restoration conferred dual therapeutic benefits by sensitizing KRAS-mutated CRC cells to 5-fluorouracil (5-FU) via ABCC5 repression and augmenting immunotherapy responsiveness via PD-L1 down-regulation. Our findings, taken together, delineate a new therapeutic paradigm with significant translational potential for improving clinical outcomes in this recalcitrant patient population.