Project description:Glioblastoma (GBM) is the deadliest brain cancer, driven in part by GBM stem cells (GSCs) that contribute to therapeutic resistance and tumor recurrence. Effective targeting and elimination of GSCs hold promise for preventing GBM recurrence and achieving potential cures. In this study, we explored the role of the epigenetic regulator SUV39H1 in GSC maintenance and GBM progression. We observed that SUV39H1 is upregulated in GBM samples compared to normal brain tissues. Single-cell RNA-seq data indicated that SUV39H1 is preferentially expressed in GSCs relative to non-stem GBM cells, possibly due to super-enhancer-mediated transcriptional activation. Knockdown of SUV39H1 in patient-derived GSCs impaired their proliferation and stemness. RNA-seq analysis revealed that SUV39H1 regulates G2/M cell cycle progression, stem cell maintenance, and cell death pathways in GSCs. Integrated ATAC-seq (assay for transposase-accessible chromatin followed by sequencing) and RNA-seq analyses demonstrated that targeting SUV39H1 altered chromatin accessibility in key genes associated with these pathways. Treatment with chaetocin, a SUV39H1 inhibitor, mimicked the effects of SUV39H1 knockdown in GSCs and sensitized them to the GBM chemotherapy drug temozolomide (TMZ). In vivo studies using an intracranial patient-derived xenograft model showed that targeting SUV39H1 inhibited GSC-driven tumor formation in mice. Our findings identify SUV39H1 as a critical regulator of GSC maintenance and suggest that targeting SUV39H1 could disrupt GSCs and enhance the efficacy of existing chemotherapy, offering a promising strategy for improving GBM treatment outcomes.
Project description:Glioblastoma (GBM) is the deadliest brain cancer, driven in part by GBM stem cells (GSCs) that contribute to therapeutic resistance and tumor recurrence. Effective targeting and elimination of GSCs hold promise for preventing GBM recurrence and achieving potential cures. In this study, we explored the role of the epigenetic regulator SUV39H1 in GSC maintenance and GBM progression. We observed that SUV39H1 is upregulated in GBM samples compared to normal brain tissues. Single-cell RNA-seq data indicated that SUV39H1 is preferentially expressed in GSCs relative to non-stem GBM cells, possibly due to super-enhancer-mediated transcriptional activation. Knockdown of SUV39H1 in patient-derived GSCs impaired their proliferation and stemness. RNA-seq analysis revealed that SUV39H1 regulates G2/M cell cycle progression, stem cell maintenance, and cell death pathways in GSCs. Integrated ATAC-seq (assay for transposase-accessible chromatin followed by sequencing) and RNA-seq analyses demonstrated that targeting SUV39H1 altered chromatin accessibility in key genes associated with these pathways. Treatment with chaetocin, a SUV39H1 inhibitor, mimicked the effects of SUV39H1 knockdown in GSCs and sensitized them to the GBM chemotherapy drug temozolomide (TMZ). In vivo studies using an intracranial patient-derived xenograft model showed that targeting SUV39H1 inhibited GSC-driven tumor formation in mice. Our findings identify SUV39H1 as a critical regulator of GSC maintenance and suggest that targeting SUV39H1 could disrupt GSCs and enhance the efficacy of existing chemotherapy, offering a promising strategy for improving GBM treatment outcomes.
Project description:Chromatin accessibility was profiled by ATAC-seq in normal and glioblastoma-derived neural stem (GNS) cells, in self-renewing conditions and in response to differentiation stimulus with bone morphogenic protein (BMP).
Project description:We over-expressed an epigenetic regulator in a glioblastoma (GBM) primary culture from an adult patient. These GBM cells have cancer stem cell phenotypes, as they have self-renewal properties and tumor initiation potential when transplanted in immunocompromised mice. ATAC-seq was performed on cells over-expressing the epigenetic regulator and control cells expressing EGFP. ATAC-Seq on glioblastoma cells that over-express EGFP or an epigenetic regulator.
Project description:Glioblastoma stem cells (GSCs) are pivotal in the recurrence and drug resistance of glioblastoma multiforme (GBM). However, precision therapeutic and diagnostic markers for GSCs have not been fully established. Here, using bioinformatics and experimental analysis, we identified P4HB, a protein disulfide isomerase, as a serum marker that maintains stemness in GSCs through the Wnt/β- catenin signaling pathway. Transcriptional silencing of P4HB induces apoptosis and diminishes stem cell-like characteristics in GSCs. Treatments with the chemical CCF624 or the China National Medical Products Administration (NMPA)-approved securinine significantly prolonged survival in patient-derived xenograft mouse models, underscoring P4HB’s potential as a therapeutic target and presenting an expedited path to clinical application through drug repurposing. Additionally, elevated P4HB levels in patient serum were found to correlate with disease progression, underscoring its utility as a biomarker and its promise for precision medicine.
Project description:SAGA and ATAC are two related transcriptional coactivator complexes, sharing the same histone acetyltransferase (HAT) subunit. The HAT activities of SAGA and ATAC are required for metazoan development but the precise role of the two complexes in RNA polymerase II transcription in mammals is less understood. To determine whether SAGA and ATAC have redundant or specific functions dependent on their HAT activities, we compared the effects of HAT inactivation in each complex with that of inactivation of either SAGA or ATAC core subunits in mouse embryonic stem cells (ESCs). We show that core subunits of SAGA or ATAC subunits are required for complex assembly, mouse ESC growth and self-renewal. Additionally, ATAC, but not SAGA subunits are required for ESC viability by regulating the transcription of translation-related genes. Surprisingly, depletion of specific or shared HAT module subunits caused a global decrease in histone H3K9 acetylation, but did not result in significant phenotypic or transcriptional defects. Thus, our results indicate that SAGA and ATAC are differentially required for viability and self-renewal of mouse ESCs by regulating transcription through different pathways, in a HAT-independent manner.