Abstract
Glioblastoma is the most common malignant brain tumor. Unfortunately, outcomes for this cancer are poor. Even with standard of care treatment, the median survival time is only 15 months and the disease is almost universally lethal. Therefore, more effective therapies are urgently needed to treat this condition. One promising treatment is chimeric antigen receptor (CAR) T cell therapy. CAR T cells are white blood cells that are engineered to kill cancer cells expressing certain antigens; however, the potential of this treatment has yet to be fully realized and further work is required for it to be more effective. One strategy for augmenting CAR T cell therapy would be to increase the expression of the targeted antigens on cancer cells. This could be done using small molecule inhibitors of epigenetic pathways that regulate expression of these antigens. Therefore, the goal of this study was to screen for epigenetic genes that regulate expression of antigens currently being targeted in CAR T cell clinical trials for glioblastoma. Using a CRISPR/Cas9 lentiviral vector library, we knocked out various genes encoding epigenetic proteins in human glioblastoma cell lines. Flow cytometry was used to sort for cells with the highest levels of target surface antigen expression. Genomic DNA was isolated from the cells with the highest surface expression of the antigens of interest. The isolated DNA was sequenced to identify the genetic manipulations responsible for increased antigen expression. Future studies will use small molecule inhibitors of the identified epigenetic modulators to augment CAR T cell therapy in mice.