Abstract 5155: A novel lipid nanoparticle for delivering sgRNA and mRNA to develop lung cancer model mice

Abstract Background: Genetically engineered mouse models (GEMMs) that develop autochthonous lung tumors are suitable to study lung tumor initiation and the tumor microenvironment involved in immune cells. However, GEMMs require lengthy mouse breeding with multiple crossing of genetic lines to develop mice carrying multiple alleles of specific genes. A more convenient approach to develop these GEMMs will facilitate lung cancer research. Methods: We have recently developed a novel lipid nanoparticle PEG-PBAE/4A3-SC8/DOPE/Cholesterol/DOTAP (hereafter, LNP) that can deliver mRNA into lung epithelial cells in mice by intratracheal (IT) injection (Liu et al., bioRxiv 2024; https://doi.org/10.1101/2024.08.22.608643). Using this LNP, we delivered different sgRNAs and/or Cre mRNA into Cas9 mice that constitutively express Cas9 (or KrasLSL-G12D/+;Cas9 mice) by IT injection and sought to develop lung cancer model mice. Results: The LNP delivery of sgRNAs targeting Eml4 (sgEml4) and Alk (sgAlk) into Cas9 mice produced autochthonous lung tumors induced by the driver oncogene EML4-ALK two months after IT injection. The LNP delivery of Cre mRNA along with sgRNA targeting the lung lineage transcription factor Nkx2-1 (sgNkx2-1) into KrasLSL-G12D/+; Cas9 mice produced autochthonous invasive mucinous adenocarcinomas of the lung (IMA) that carry KrasG12D with loss of NKX2-1 and de novo expression of the gastrointestinal transcription factor HNF4A while the LNP delivery of only Cre mRNA into KrasLSL-G12D/+; Cas9 mice produced autochthonous non-mucinous adenoma/adenocarcinoma two months after IT injection. Conclusion: Delivery of our novel LNPs encapsulating sgRNAs and/or Cre mRNA into Cas9 or KrasLSL-G12D/+;Cas9 mice by IT injection successfully resulted in producing autochthonous lung tumors driven by EML4-ALK or KRASG12D similar to traditional GEMMs. This approach using our LNPs will allow for agile development of lung cancer mouse models for investigating novel lung cancer therapeutics. Citation Format: Bingxin Liu, Yutaka Maeda. A novel lipid nanoparticle for delivering sgRNA and mRNA to develop lung cancer model mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5155.