Chromatin Modification Abnormalities by CHD7 and KMT2C Loss Promote Medulloblastoma Progression [ATAC-seq]

Medulloblastoma, a common malignant pediatric brain tumor that typically originating from the cerebellum, is characterized by mutations in chromatin modifiers, highlighting the significance of epigenomic abnormalities in their progression. To prove this significance, the development and use of animal models that closely recapitulate the disease have been highly effective. However, due to substantial time and cost limitations of developing genetically engineered mouse models, a complete understanding of the oncogenic potential of chromatin modifiers’ mutations found in human medulloblastomas is still elusive. In this study, we address this by CRISPR-mediated gene editing platform to knock out chromatin modifiers mutated human in SHH-subgroup medulloblastoma as well as the Ptch1 gene in cerebellar granule neuron progenitors. We functionally screened molecules involved tumor formation, identifying CHD7 and KMT2C as tumor suppressor genes. Multi-layered omics analysis revealed that these molecules epigenetically regulate the expression of Neurod1 that encodes a transcription factor crucial for neuronal differentiation, through histone H3 modification. Mutations impairing these factors suppress Neurod1, accelerating tumor growth. Conversely, forced expression of Neurod1 inhibits proliferation and promotes differentiation, underscoring its role as a key regulator in medulloblastoma aggressiveness. These findings not only demonstrate converging epigenomic abnormalities in SHH-subgroup medulloblastoma but also hold significant potential for evaluating epigenetic drugs targeting medulloblastoma, advancing the development of novel treatments.