Targeted DYRK1A/mTOR co-delivery system for head and neck squamous cell carcinoma therapy

Head and neck squamous cell carcinoma (HNSCC) is a general term for malignant tumors originating from the mucosal squamous epithelium of the head and neck, with common subtypes including oral squamous cell carcinoma, oropharyngeal squamous cell carcinoma, hypopharyngeal squamous cell carcinoma and laryngeal squamous cell carcinoma. Its targeted therapy is hampered by the limited efficacy of single-agent treatment and a high rate of drug resistance. Thus, an in-depth investigation into the mechanisms of drug resistance and the exploration of effective combination therapeutic regimens have become an urgent necessity in the current research field of HNSCC. INDY, a specific inhibitor of DYRK1A, was screened and identified via molecular docking. A pH-responsive nanocarrier, INDY+INK128@ZIF-8 (II@ZIF-8), was constructed to achieve the co-delivery of INDY and mTOR inhibitors (mTORi) INK128. Bioinformatics analyses were performed to verify the differential expression and functional correlations of DYRK1A. In vitro experiments used Cal27 and SCC25 oral squamous cell carcinoma cell lines as research models, and employed the CCK-8 assay, colony formation assay, flow cytometry and Western blot analysis to evaluate the efficacy and underlying mechanisms of II@ZIF-8. In vivo, subcutaneous xenograft tumor models in nude mice were established, and HE staining and IHC were conducted to validate the anti-tumor efficacy of II@ZIF-8. Bioinformatics analyses revealed that DYRK1A was a core differentially expressed gene between HNSCC tumor tissues and normal tissues. II@ZIF-8 inhibited the proliferation and migration of Cal27 and SCC25 cells in a concentration-dependent manner. At the molecular level, it significantly downregulated the phosphorylation levels of p-ERK, p-AKT and p-S6, the key downstream molecules of the KRAS signaling pathway. At a dose of 4 mg/kg, II@ZIF-8 markedly suppressed the growth of subcutaneous xenografts in nude mice, resulting in reduced tumor volume and weight as well as an increased necrotic area in tumor tissues. Meanwhile, it significantly downregulated the expressions of p-S6, p-ERK and p-AKT in tumor tissues in a dose-dependent manner. DYRK1A serves as a key regulatory node of the KRAS signaling axis, driving the persistent activation of downstream signaling pathways by sustaining KRAS activation. Through a synergistic mode of “upstream blockade of the DYRK1A-KRAS axis plus downstream mTORi” combined with targeted and precise drug release, II@ZIF-8 can disrupt the signal compensation network of tumor cells and effectively overcome single-agent resistance to mTORi. This thus provides a safe and highly efficient precision therapeutic strategy for HNSCC patients with aberrant activation of the KRAS signaling pathway.