Nanoparticle-Mediated Cosilencing of Drug Resistance and Compensatory Genes Enhances Lung Cancer Therapy

Non-small cell lung cancer (NSCLC) is challenging to treat due to acquired drug resistance, leading to high mortality rates. NSCLC patients with mutations in the epidermal growth factor receptor (EGFR) region are treated with tyrosine kinase inhibitors (TKI) as a first-line treatment, but many develop resistance within 1-2 years. AXL overexpression contributes to drug resistance in over 25% of patients, as shown by tumor analyses, prompting efforts to develop small-molecule inhibitors targeting AXL. However, we found that AXL repression increases compensatory FN14 signaling that could affect the therapeutic efficacy. Therefore, we chose to evaluate therapeutic efficacy after silencing both AXL and FN14 genes using short interfering RNA (siRNA) therapy. While siRNAs are more selective than small-molecule inhibitors, they are prone to in vivo degradation. To address this, we developed gelatin nanoparticles carrying siRNAs targeting AXL and FN14 (GsiAF). These nanoparticles were designed to protect siRNA from serum degradation and to allow antibody functionalization on their surface. We demonstrate that GsiAF selectively and effectively silences the respective genes under both in vitro and in vivo conditions, thereby overcoming compensatory FN14 signaling. Results indicate that GsiAF was successful in delivering siRNAs to tumors and downregulating both AXL and FN14 genes. We show that coinhibition of AXL and FN14 has effectively decreased TKI resistance in cancer cells and significantly reduced tumor growth in mice bearing lung cancer. The gelatin-siRNA nanoconstruct combined with TKI represents a promising strategy for overcoming drug resistance in NSCLC and other cancers, with potential for future clinical translation.