Abstract
Squamous cell carcinomas of the head and neck (HNSCC) originate in the upper aerodigestive tract, including the oral cavity, pharynx, and larynx. Current treatments of locally advanced HNSCC often lead to high treatment failure, and disease recurrence, resulting in poor survival rates. Advances in mRNA technologies and lipid nanoparticle (LNP) delivery systems led to several clinical trials involving LNP-CRISPR-Cas9 mRNA-based therapeutics. Despite these advances, achieving cell-type-specific extrahepatic mRNA delivery is still challenging. This study introduces a safe and effective intratumoral EGFR-targeted CRISPR-LNP delivery strategy for knocking out SOX2, which is a cancer-specific gene. To assess their therapeutic potential, it is shown that LNPs made from ionizable lipids with helper lipids co-encapsulating Cas9 mRNA and sgRNA targeting SOX2 (sgSOX2), lead to a ≈60% reduction in HNSCC cell viability in vitro. Next, using a xenograft HNSCC mouse model, targeted delivery of 𝜶EGFR- CRISPR-sgSOX2-LNPs to HNSCC cells resulted in a 90% inhibition of tumor growth and a 90% increase in survival for > 84 days, with tumor disappearance observed in 50% of the mice. These findings emphasize the potential of targeted mRNA-Cas9-LNPs in clinically accessible solid tumors, specifically in reaching tumor cells and inducing persistent therapeutic responses in tumors with high-recurrence rates like HNSCC.