Abstract 1219: In vivo delivery of CRISPR-Cas9 using lipid nanoparticles enables ATAD3A gene depletion to enhance RAS-targeted therapy

Abstract Targeting mitochondrial oncoproteins presents a new concept in developing effective cancer therapeutics. ATAD3A is a nuclear-encoded mitochondrial enzyme that contributes to mitochondrial dynamics, cholesterol metabolism, and signal transduction. Our previous study has demonstrated elevated expression of ATAD3A in head and neck squamous cell carcinoma (HNSCC) primary tissues and cultured cell lines. Loss of function suppresses HNSCC cell growth and elicits tumor regression in orthotopic tumor-bearing mice. Mechanistically, ATAD3A interacts with ERK1/2 in the mitochondria of HNSCC cells in the presence of VDAC1, and the ATAD3A-ERK1/2 signaling axis drives HNSCC development in a RAS-independent fashion. CRISPR-Cas9 has revolutionized genome engineering and has been intensively used to modify cancer-associated genes. However, challenges remain as CRISPR editing components must be transported into cells to exert their function. There is a need to explore effective in vivo delivery systems to accelerate the clinical use of CRISPR-Cas9. As no drug is available to target ATAD3A directly, we developed CRISPR-based ATAD3A-targeting nanodrugs by loading Cas9 mRNA and anti-ATAD3A sgRNAs into lipid nanoparticles (LNPs) that have become clinically acceptable delivery system due to low toxicity and high delivery efficacy and biocompatibility. As expected, treatment tongue tumors established in NSG mice with LNP-sgATAD3A remarkably repressed tumor growth. Most interestingly, the addition of LNP-sgATAD3A to the RAS inhibitor salirasib potentiated anticancer activity for HNSCC compared with the efficacy resulting from single-arm treatment. These novel and significant findings demonstrate a novel approach to inhibiting ATAD3A in tumor cells and provide a possible therapeutic strategy to enhance the success of multimodality therapy in cancer patients. Citation Format: Fanghui Chen, Liwei Lang, Yamin Li, Wei Zheng, Yong Teng. In vivo delivery of CRISPR-Cas9 using lipid nanoparticles enables ATAD3A gene depletion to enhance RAS-targeted therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1219.