Tmod-03. A Swine Model of Glioblastoma Induced by Somatic Gene Modification

Abstract

Glioblastoma (GBM) is the most common and malignant primary brain tumor. Novel therapeutic development for GBM is desperately needed, as the standard of care universally fails to cure patients and the 5-year survival rate remains extremely low. GBM therapeutic development is hampered by the lack of relevant preclinical models for preclinical studies. To mitigate this problem, we have developed a genetic model of GBM in outbred, immune-proficient swine which have comparable brain size and anatomy to humans. We developed methods for introducing genome engineering tools to minipig brain in vivo by direct injection of gene delivery reagents to the lateral ventricle, altering major signaling pathways frequently changed in human GBM. Using this technique, we have delivered a combination of expression vectors for oncogenes and targeted nucleases to disrupt tumor suppressor genes commonly altered in human GBM. We have altered six major human GBM-associated signaling pathways and modeled molecular GBM subclasses. We have also engineered a secreted tumor reporter that can be used to monitor tumor size through a simple blood test. This somatic cell gene-modification platform we have developed in the minipig allows us to reproduce the genetic heterogeneity seen in GBM and understand the impact of the tumor microenvironment, immune system, and response to therapy. This minipig model of GBM Is being used to test the standard of care against novel therapies in preclinical studies, and biopsy, surgical, imaging, and radiation therapy techniques are being optimized in this mode to improve clinical trial success rates and patient outcomes. Funding for this study is provided by the National Institutes of Health though SBIR grant # 1R43CA235837-01A1.