Using Crispr/Cas9 To Generate Primary Soft Tissue Sarcoma In Genetically Engineered And Wild-Type Mice

Genetically engineered mouse models (GEMMs) that employ site-specific recombinase (SSR) technology are important tools for pre-clinical studies, but this approach is costly and time-consuming. Here, we show that the CRISPR/Cas9 system can be used to efficiently complement existing GEMMs of sarcoma and generate primary sarcomas in wild type mice. Mice with the genotype KrasLSL-G12D/+; Rosa26LSL-Cas9-EGFP/+ received intramuscular delivery of an adenovirus expressing Cre recombinase and a single guide RNA (sgRNA) targeting Trp53. Cre-mediated expression of oncogenic Kras and Cas9, in combination with CRISPR/Cas9-mediated knockout of Trp53, was sufficient to generate primary soft tissue sarcomas. These tumors arose with kinetics similar to those generated using the Cre-loxP system to activate oncogenic Kras and delete Trp53 alleles. Additionally, we injected an adenovirus containing Cas9 and sgRNAs targeting Nf1 and Trp53 into the sciatic nerve of wild type mice. These mice formed malignant peripheral nerve sheath tumors (MPNSTs) in the same timeframe as MPNSTs generated using the Cre-loxP system to delete Nf1 and Ink4a/Arf alleles in GEMMs. These data demonstrate that CRISPR/Cas9 can be used to generate soft tissue sarcomas in wild type mice. Moreover, these results suggest that this technology can complement existing GEMMs for rapid assessment of tumor-modifying genes. These tools should decrease the time and expense associated with employing autochthonous mouse models of sarcoma for preclinical research. Citation Format: Jianguo Huang, Mark Chen, Melodi J. Whitley, Hsuan-Cheng Kuo, Andrea Walens, Yvonne M. Mowery, David V. Mater, William Eward, Diana M. Cardona, Lixia Luo, Yan Ma, Christopher E. Nelson, Jacqueline N. Robinson-Hamm, Charles A. Gersbach, Rebecca D. Dodd, David G. Kirsch. Using CRISPR/Cas9 to generate primary soft tissue sarcoma in genetically engineered and wild-type mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2810. doi:10.1158/1538-7445.AM2017-2810