Data from A Programmable <i>In Vivo</i> CRISPR Activation Model Elucidates the Oncogenic and Immunosuppressive Functions of MYC in Lung Adenocarcinoma

Abstract

<div><p>Conventional genetically engineered mouse models (GEMM) are time-consuming, laborious, and offer limited spatiotemporal control. Here, we describe the development of a streamlined platform for <i>in vivo</i> gene activation using CRISPR activation (CRISPRa) technology. Unlike conventional GEMMs, this model system allows for flexible, sustained, and timed activation of one or more target genes using single or pooled lentiviral guides. <i>Myc</i> and <i>Yap1</i> were used as model oncogenes to demonstrate gene activation in primary pancreatic organoid cultures <i>in vitro</i> and enhanced tumorigenic potential in <i>Myc</i>-activated organoids when transplanted orthotopically <i>in vivo</i>. Implementation of this model as an autochthonous lung cancer model showed that transduction-mediated activation of <i>Myc</i> led to accelerated tumor progression and significantly reduced overall survival relative to nontargeted tumor controls. Furthermore, <i>Myc</i> activation led to the acquisition of an immune suppressive, “cold” tumor microenvironment. Cross-species validation of these results using publicly available RNA/DNA-seq datasets linked MYC to a previously described immunosuppressive molecular subtype in patient tumors, thus identifying a patient cohort that may benefit from combined MYC- and immune-targeted therapies. Overall, this work demonstrates how CRISPRa can be used for rapid functional validation of putative oncogenes and may allow for the identification and evaluation of potential metastatic and oncogenic drivers through competitive screening.</p>Significance:<p>A streamlined platform for programmable CRISPR gene activation enables rapid evaluation and functional validation of putative oncogenes <i>in vivo</i>.</p></div>