Abstract 861: Precise excision of an oncogenic allele of tumor by Adenovirus-based CRISPR/Cas9 system induces tumor regression

Abstract

Abstract Approximately 15% of non-small cell lung cancer patients possesses several mutations in the epidermal growth factor receptor (EGFR) gene, which plays a critical role in tumor progression. To this end, we demonstrate that an adenovirus-mediated co-delivery of Cas9 and a guide RNA targeting oncogenic EGFR mutation commonly found in lung cancer can selectively remove oncogenic allele while being inactive against wild-type EGFR allele. An EGFR mutant harboring a single-nucleotide missense mutation (CTG to CGG) was targeted as this mutation leads to generation of protospacer-adjacent motif sequence recognized by the Cas9 protein of S. pyogenes. The CRISPR/Cas9-mediated excision of mutant EGFR allele with high indel rate led to potent lung cancer cell killing. Importantly, intratumoral administration of Ad-based CRISPR/Cas9 system led to potent tumor growth inhibition and complete tumor regressions in number of mice harboring EGFR mutant xenograft tumors. Collectively, our findings show that precise and controlled excision of oncogenic mutation by Ad-mediated expression of CRISPR/Cas9 system offers a powerful genomic surgical strategy to excise oncogenic mutations to treat cancers. Note: This abstract was not presented at the meeting. Citation Format: Taeyoung Koo, A-Rum Yoon, Sangsu Bae, Jin-Soo Kim, Chae-Ok Yun. Precise excision of an oncogenic allele of tumor by Adenovirus-based CRISPR/Cas9 system induces tumor regression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 861.