Project description:Chromatin accessibility discriminates stem from mature cell populations, enabling the identification of primitive stem-like cells in primary tumors, such as Glioblastoma (GBM) where self-renewing cells driving cancer progression and recurrence are prime targets for therapeutic intervention. We show, using single-cell chromatin accessibility, that primary GBMs harbor a heterogeneous self-renewing population whose diversity is captured in patient-derived glioblastoma stem cells (GSCs). In depth characterization of chromatin accessibility in GSCs identifies three GSC states: Reactive, Constructive, and Invasive, each governed by uniquely essential transcription factors and present within GBMs in varying proportions. Orthotopic xenografts reveal that GSC states associate with survival, and identify an invasive GSC signature predictive of low patient survival. Our chromatin-driven characterization of GSC states improves prognostic precision and identifies dependencies to guide combination therapies.
Project description:Here we performed a ChIP-seq experiment for Zeb1 trancription factor on a sample of adherent cultures of human neural stem cells (Cb192 cell line) and of a human glioblastoma cancer stem-like cell line (NCH421k). The result is the generation of the genome-wide maps for Zeb1 binding to chromatin in human neural stem cells and glioblastoma stem-like cells.
Project description:Glioblastoma is an incurable brain cancer characterized by high genetic and pathological heterogeneity. Here we mapped active chromatin landscapes with gene expression, whole-exomes, copy number profiles, and DNA methylomes across 44 glioblastoma stem cell (GSCs) models, 50 primary glioblastomas, and 10 neural stem cells (NSCs) with the goal of identifying essential super enhancer (SE)-associated genes and the core transcription factors that establish them and glioblastoma identity. Glioblastomas segregate with two dominant enhancer profiles that coopt unique developmental transcription factor regulatory programs to enforce tumor identity. From group specific enhancer profiles, we inferred core transcription factors that define subgroup identity. These transcription factors show higher activity in glioblastomas versus normal neural stem cells, are associated with poor clinical outcomes, and are required for glioblastoma growth in vitro and in vivo. Given challenges with genetically-defined targeted therapies for glioblastoma, we propose targeting underlying transcriptional identity may serve as an important therapeutic strategy.
Project description:Chromatin modifications instruct genome function through spatiotemporal recruitment of regulatory factors to the genome. However, how these modifications define the proteome composition at distinct chromatin states remains to be fully characterized. Here, we made use of natural protein domains as modular building blocks to develop engineered chromatin readers (eCRs) selective for histone and DNA modifications. By stably expressing eCRs in mouse embryonic stem cells and measuring their subnuclear localisation, genomicdistribution and histone-PTM-binding preference, we first demonstrate their applicability as selective chromatin binders in living cells. Finally, we exploit the binding specificity of eCRs to establish ChromID, a new method for chromatin-dependent proteome identification based on proximity biotinylation. We use ChromID to reveal the proteome at distinct chromatin states in mouse stem cells, and by using a synthetic dual-modification reader, we furthermore uncover the protein composition at bivalent promoters marked by H3K4me3 and H3K27me3. These results highlight the applicability of ChromID as novel method to obtaina detailed view of the protein interaction network determined by the chemical language on chromatin.
Project description:Glioblastoma is an incurable brain cancer characterized by high genetic and pathological heterogeneity. Here we mapped active chromatin landscapes with gene expression, whole-exomes, copy number profiles, and DNA methylomes across 44 glioblastoma stem cell (GSCs) models, 50 primary glioblastomas, and 10 neural stem cells (NSCs) with the goal of identifying essential super enhancer (SE)-associated genes and the core transcription factors that establish them and glioblastoma identity. Glioblastomas segregate with two dominant enhancer profiles that coopt unique developmental transcription factor regulatory programs to enforce tumor identity. From group specific enhancer profiles, we inferred core transcription factors that define subgroup identity. These transcription factors show higher activity in glioblastomas versus normal neural stem cells, are associated with poor clinical outcomes, and are required for glioblastoma growth in vitro and in vivo. Given challenges with genetically-defined targeted therapies for glioblastoma, we propose targeting underlying transcriptional identity may serve as an important therapeutic strategy.