CBIO-19. GENOME SHREDDING ENABLES CRISPR-MEDIATED GLIOBLASTOMA ONCOLYSIS

Abstract

Abstract Glioblastoma (GBM) is the most common and lethal primary brain tumor in adults 1. Despite multimodal treatment regimens including surgical resection, radio- and chemotherapy, the growth of residual tumor often results in therapy resistance and ultimately death. GBMs are highly diffuse and exhibit extensive intratumoral heterogeneity 2,3, confounding diagnostic efforts and presenting opportunities for therapy evasion. Therefore, innovative treatment paradigms that can efficiently eliminate GBM cells irrespective of their mutational and epigenetic profile are urgently needed. CRISPR technologies have revolutionized medicine by enabling targeted genome editing through RNA-guided introduction of DNA double-strand breaks 4,5. Here, we show that CRISPR-Cas9 mediated genome fragmentation through targeting of highly repetitive loci, termed “genome shredding”, enables rapid and robust elimination of GBM cells. We characterized genome shredding across mammalian and vertebrate cells, and identified optimal repetitive pan-vertebrate and species-specific loci. Genome shredding is equally effective in temozolomide (TMZ)-sensitive and -resistant GBM cells, and multi-cycle treatment regimens are feasible. Importantly, when deployed in intracerebral GBM xenografts through local delivery, CRISPR-Cas9 genome shredding efficiently eliminated all targeted cells. Together, genome shredding enables the rapid and efficient fragmentation of a target cell’s genome and subsequent DNA damage-induced cell death. This provides an innovative treatment paradigm that is independent of a tumor’s mutational and epigenetic profile and leverages CRISPR-Cas9 as a breakthrough therapeutic modality for GBM.