Ripk2 Dictates Nod2 Mediated Chemotherapy Resistance Through Inhibiting Pyroptosis

Cisplatin resistance in HNSCC remains a major therapeutic challenge. Evidence suggests that intratumoral microbiota modulates chemotherapy resistance by reshaping the tumor microenvironment, yet the underlying mechanisms and targeted strategies remain elusive. We found that the NOD2-RIPK2 signaling pathway as a critical hub for chemoresistance. Notably, NOD2 receptors are activated by bacterial peptidoglycan, linking microbiota to resistance. To address this, our study aims to delineate the molecular mechanisms by which the NOD2-RIPK2 axis mediates chemoresistance, and develop an engineered bacterial outer membrane vesicle (OMV)-based siRNA delivery system to simultaneously silence RIPK2 and activate NOD2 signaling, thereby reversing cisplatin resistance Integrated transcriptomic and single-cell analyses identified RIPK2 as a key regulator of chemoresistance. RIPK2-knockdown models generated by lentiviral transfection revealed its mediation of chemoresistance via the NOD2-RIPK2 pathway through functional and molecular assays. Animal studies assessed whether targeting this pathway enhances cisplatin efficacy. Engineered bacterial OMVs delivering RIPK2 siRNA and activating NOD2 via intrinsic ligands enabled dual-pathway modulation, proposing a novel strategy to reverse chemoresistance. RIPK2 knockdown suppressed tumor proliferation in vitro and in vivo, and is more sensitive to cisplatin. RIPK2 dictates NOD2 mediated chemotherapy resistance through inhibiting pyroptosis. The OMV-siRIPK2 system further potentiated tumor suppression in preclinical models. RIPK2 dictates NOD2 pathway outcomes: its deletion converts NOD2 activation from pro-survival to pro-pyroptosis. Our OMV-based strategy synergistically silences RIPK2 and activate NOD2 pathways represents a breakthrough in overcoming HNSCC chemoresistance, offering a transformative approach to reverse cisplatin resistance in HNSCC.