TMOD-19. SOMATIC GENOME EDITING WITH THE RCAS-CRISPR/Cas9 SYSTEM FOR PRECISION GLIOMA MODELING

Abstract

It has been gradually established that the vast majority of human tumors are extraordinarily heterogeneous at a genetic level. To accurately recapitulate this complexity, it is now evident that in vivo animal models of cancers will require to recreate not just a handful of simple genetic alterations, but possibly dozens and increasingly intricate. Here we have combined the RCAS/tv-a system with the CIRSPR/Cas9 genome editing tools to somatically target neural stem cells (NSCs) for precise modeling of human glioma. We show that deletion, both in pups and adult mice, of a variety of known tumor suppressor genes (Trp53, Cdkn2a and Pten), in combination with the expression of an oncogene driver, leads to high-grade glioma formation. Moreover, by simultaneously delivery into NSCs of pairs of gRNAs we show for the first time that the Bcan-Ntrk1 gene fusions, is able to induce high-grade gliomas. We further established that cells derived from Bcan-Ntrk1 tumors are remarkably sensitive to a Pan-Ntrk inhibitor. Lastly, using homology directed repair (HDR), we generated the Braf V600E mutation into NSCs and we demonstrated that it's sufficient to induce glioma tumor formation. In summary, we have developed an extremely powerful and versatile mouse model for in vivo somatic genome editing. Our system will elicit the generation of more accurate glioma models, particularly suitable for preclinical testing.