Project description:Cbx3 (HP1γ) that is a member of the heterochromatin protein 1 family play important roles in development and differentiation. To determine the regulatroy mechanisms of Cbx3 during neural differentiation from ESCs to NPCs, we performed RNA-seq analysis of ESCs or ESC-derived NPCs depleted for Cbx3 or Cbx3-assocatied Mediator subunit Med26.
Project description:Cbx3 (HP1γ) that is a member of the heterochromatin protein 1 familiy enriched in gene bodies of pluripotent ESCs but promoters of differentiated pre-iPSCs. To determine whether Cbx3 becomes enriched at promoters to influence gene regulation during differentiation, we converted ESCs to NPCs in monolayer culuture and performed genomewide ChIP-seq of Cbx3. Our results shows that Cbx3 enriches at the promoters of genes upon differentiation of ESCs to NPCs and stablizes the binding of Mediator subunit Med26 to pre-initiation complex (PIC) in NPCs.
Project description:ZNF462 haploinsufficiency is linked to Weiss-Kruszka Syndrome, a genetic disorder characterized by neurodevelopmental defects including Autism. Though conserved in vertebrates and essential for embryonic development the molecular functions of ZNF462 remain unclear. We identified its murine homolog ZFP462 in a screen for mediators of epigenetic gene silencing. Here, we show that ZFP462 safeguards neural lineage specification of mouse embryonic stem cells (ESCs) by targeting the H3K9-specific histone methyltransferase complex G9A/GLP to silence mesoendodermal genes. ZFP462 binds to transposable elements (TEs) that are potential enhancers harboring ESC-specific transcription factor (TF) binding sites. Recruiting G9A/GLP, ZFP462 seeds heterochromatin, restricting TF binding. Loss of ZFP462 in ESCs results in increased chromatin accessibility at target sites and ectopic expression of mesoendodermal genes. Taken together, ZFP462 confers lineage- and locus-specificity to the broadly expressed epigenetic regulator G9A/GLP. Our results suggest that aberrant activation of lineage non-specific genes in the neuronal lineage underlies ZNF462-associated neurodevelopmental pathology.
Project description:HP1gamma/Cbx3 is one of the components of heterochromatin and strongly expressed in neural stem cells and neurospheres. To evaluate the functions of HP1gamma, gene expressions in wild-type and HP1gamma KO neurospheres were compared.
Project description:Glioblastoma (GBM), an aggressive brain malignancy with a cellular hierarchy dominated by GBM stem cells (GSCs), evades anti-tumor immunity through mechanisms that remain incompletely understood. Like most cancers, GBMs undergo metabolic reprogramming towards glycolysis to generate lactate. Here, we show that lactate production by patient-derived GSCs and microglia induces tumor cell epigenetic reprogramming through histone lactylation, an activating modification that leads to immunosuppressive transcriptional programs and suppression of microglial phagocytosis via transcriptional upregulation of CD47, a “don’t eat me” signal, in GBM cells. Leveraging these findings, pharmacologic targeting of lactate production augments efficacy of anti-CD47 therapy. Mechanistically, lactylated histone interacts with the heterochromatin component chromobox protein homolog 3 (CBX3). Although CBX3 does not possess direct lactyltransferase activity, CBX3 binds histone acetyltransferase (HAT) P300 to induce increased P300 substrate specificity toward lactyl-coA and a transcriptional shift toward an immunosuppressive cytokine profile. Targeting CBX3 inhibits tumor growth by both tumor cell-intrinsic mechanisms and increased tumor cell phagocytosis. Collectively, these results suggest that lactate mediates a metabolism-induced epigenetic reprogramming in GBM that contributes to CD47-dependent immune evasion, which can be leveraged to augment efficacy of immune-oncology therapies.
Project description:Glioblastoma (GBM), an aggressive brain malignancy with a cellular hierarchy dominated by GBM stem cells (GSCs), evades anti-tumor immunity through mechanisms that remain incompletely understood. Like most cancers, GBMs undergo metabolic reprogramming towards glycolysis to generate lactate. Here, we show that lactate production by patient-derived GSCs and microglia induces tumor cell epigenetic reprogramming through histone lactylation, an activating modification that leads to immunosuppressive transcriptional programs and suppression of microglial phagocytosis via transcriptional upregulation of CD47, a “don’t eat me” signal, in GBM cells. Leveraging these findings, pharmacologic targeting of lactate production augments efficacy of anti-CD47 therapy. Mechanistically, lactylated histone interacts with the heterochromatin component chromobox protein homolog 3 (CBX3). Although CBX3 does not possess direct lactyltransferase activity, CBX3 binds histone acetyltransferase (HAT) P300 to induce increased P300 substrate specificity toward lactyl-coA and a transcriptional shift toward an immunosuppressive cytokine profile. Targeting CBX3 inhibits tumor growth by both tumor cell-intrinsic mechanisms and increased tumor cell phagocytosis. Collectively, these results suggest that lactate mediates a metabolism-induced epigenetic reprogramming in GBM that contributes to CD47-dependent immune evasion, which can be leveraged to augment efficacy of immune-oncology therapies.