Somatic CRISPR/Cas9-mediated tumor suppressor disruption enables versatile murine cancer modeling

Recent cancer genome sequencing studies have identified numerous novel candidate driver genes. In vivo functional investigation of oncogenes using somatic gene transfer has been successfully exploited as a versatile means to validate their pathogenic relevance. In contrast, such functional analyses have been hampered for candidate tumor suppressor genes, e.g. by insufficient knockdown using RNAi-mediated approaches. In order to provide a flexible method for investigating loss-of-function mutations and their potential role in tumorigenesis, we have established CRISPR/Cas9-mediated somatic gene disruption, allowing for in vivo deletion of candidate tumor suppressor genes. We demonstrate the utility of this approach by somatic disruption of the Ptch1 gene in the mouse cerebellum, leading to the formation of medulloblastoma faithfully resembling the SHH-driven subgroup of the disease. This in vivo method for validation of candidate tumor suppressor genes provides a fast and convenient system for the generation of faithful animal models of human cancer. We used gene expression arrays to evaluate the transcriptional profiles of malignant cerebellar tumours generated using CRISPR/Cas9 technology designed to disrupt the Ptch1 tumour suppressor gene in the embryonic and neonatal mouse cerebellum.