Single Cell Analysis of the Infiltrative Margins of Glioblastoma and Post Treatment Recurrence

PROJECT SUMMARY Glioblastoma (GBM) is a deadly form of malignant glioma against which conventional targeted therapies and immunotherapies have had limited success. Both intratumoral heterogeneity and the complexities of drug delivery in the brain are formidable challenges in neuro-­oncology, while the “immune cold” nature of these tumors poses challenges to immunotherapy. We recently discovered that acute tissue slices of human GBM surgical specimens recapitulate the detailed cellular and molecular features of glioma tissue and that, when combined with single-­cell RNA-­seq, can be used to identify cellular subpopulations that are sensitive to a given drug. These models are particularly notable for their preservation of the immune microenvironment and quiescent GBM cell populations. We propose to use this acute slice model to 1) identify the targetable cellular phenotypes and differential drug responses in the core and infiltrative margins of GBM by comparing the effects of cytotoxic drugs that preferentially target proliferating glioma cells (the topoisomerase inhibitors etoposide and topotecan) and quiescent glioma cells (the ferroptopsis inducing drug RSL3), alone and in combination, 2) determine the effects of combining ferroptosis-­inducing therapy with immune-­modulatory treatments with a STING agonist (cyclic dinucleotide) using slices generated from the core and margins of GBM. We will also test these drugs and drug combinations in immunocompetent orthotopic glioma mouse models and orthotopic xenografts of patient derived glioma cells to assess the effects on glioma progression and survival.