GSE123760
HDAC and NF?B antagonists synergistically inhibit growth and metastatic dissemination of MYC-driven medulloblastoma
Aberrant oncogenic activation of MYC drives tumorigenesis in the most aggressive subset of medulloblastoma, the most common malignant brain tumor in childhood. Metastatic dissemination at diagnosis and at recurrence is commonly observed in MYC-driven medulloblastomas. Since these tumors display remarkable resistance to standard multimodal therapeutic approaches, epigenetic modulators commonly altered in these tumors are highly promising targets for novel therapeutic approaches. Here, we report on a cross-entity, high-throughput epigenetic drug screen to evaluate therapeutic vulnerabilities in the most common malignant primary brain tumors. Specifically, we performed a primary screen including 78 epigenetic inhibitors and a secondary screen including 20 histone deacetylase inhibitors (HDACi) to compare response profiles in atypical teratoid/rhabdoid tumor (AT/RT, n=11), medulloblastoma (n=14), and glioblastoma (n=14). This unbiased approach revealed preferential activity of HDACi in MYC-driven medulloblastoma. Importantly, the class I selective HDACi CI-994 showed significant cell viability reduction mediated by induction of apoptosis in MYC-driven medulloblastoma, with little to no activity in non-MYC-driven medulloblastoma, AT/RT, and glioblastoma in vitro. Notably, CI-994 displayed antitumoral effects at the primary site and the metastatic compartment in two orthotopic mouse models of MYC-driven medulloblastoma. Furthermore, synergistic drug screening and RNA sequencing revealed NF?B pathway induction as a mechanism of resistance to CI-994 treatment. Taken together, our findings identified MYC pathway activation as a predictive biomarker for epigenetic treatment intervention in high-risk medulloblastoma and provide a preclinical rationale for further exploration of CI-994 combined with NF?B pathway inhibitors in the treatment of MYC-driven medulloblastoma. Overall design: Cell lines were treated with CI-994 IC50 concentration or DMSO for 48 hours