Project description:Lysine27Methionine mutations (K27M) in the histone H3 (H3.3 and H3.1) are highly prevalent in pediatric high-grade gliomas (HGG). This study found H3.3K27M caused the upregulation of multiple cancer/testis (CT) antigens, include IL13RA2 and VCX family proteins. Overexpression of VCX3A/B stimulates the expression of genes involved in immune response.
Project description:Single-nucleus RNA sequencing (snRNA-seq) was used to profile the transcriptome of 16,015 nuclei in human adult testis. This dataset includes five samples from two different individuals. This dataset is part of a larger evolutionary study of adult testis at the single-nucleus level (97,521 single-nuclei in total) across mammals including 10 representatives of the three main mammalian lineages: human, chimpanzee, bonobo, gorilla, gibbon, rhesus macaque, marmoset, mouse (placental mammals); grey short-tailed opossum (marsupials); and platypus (egg-laying monotremes). Corresponding data were generated for a bird (red junglefowl, the progenitor of domestic chicken), to be used as an evolutionary outgroup.
Project description:Recent studies have identified a Lys 27-to-methionine (K27M) mutation at one allele of H3F3A, one of the two genes encoding histone H3 variant H3.3, in 60% of high-grade pediatric glioma cases. The median survival of this group of patients after diagnosis is ∼1 yr. Here we show that the levels of H3K27 di- and trimethylation (H3K27me2 and H3K27me3) are reduced globally in H3.3K27M patient samples due to the expression of the H3.3K27M mutant allele. Remarkably, we also observed that H3K27me3 and Ezh2 (the catalytic subunit of H3K27 methyltransferase) at chromatin are dramatically increased locally at hundreds of gene loci in H3.3K27M patient cells. Moreover, the gain of H3K27me3 and Ezh2 at gene promoters alters the expression of genes that are associated with various cancer pathways. These results indicate that H3.3K27M mutation reprograms epigenetic landscape and gene expression, which may drive tumorigenesis. We performed chromatin-immunoprecipitation of H3K27me3, H3K4me3, and EZH2 in SF7761 and NSC cell lines. And do RNA-seq in SF7761, SF8828 and NSC cell lines. SF7761 and SF8628 cell lines from patients harboring the histone H3.3 K27M mutation were obtained from Hashizume et al. (2012). NSCs (N7800-100) were purchased from Invitrogen and cultured and maintained in NSC medium (A10509-01, StemPro NSC SFM, Invitrogen).
Project description:Histone H3.1/3.2K27M and H3.3K27M mutation are driver mutations frequently identified in diffuse midline glioma (DMG). However, the precise mechanism by which H3K27M mediates tumorigenesis remains incompletely understood. By carrying out bait Protein-Protein Interaction followed by genome-wide screening (bPPI-seq) in H3.3WT and H3.3K27M mouse NSC models, we identified a novel histone reader CBFA2T2, which recognizes non-mutated or un-modified histone H3K27. Importantly, CBFA2T2 binding to H3K27, mediated by the NHR2 domain, is abrogated by the H3K27M oncogenic mutation. In H3.3 wildtype cells, CBFA2T2 represses transcription of genes involved in carbon metabolism and TCA cycle through its binding to H3K27. This alters the α-KG/Succinate (alpha-ketoglutarate/ Succinate) ratio and indirectly impacts H3K27me3 level, possibly through affecting the H3K27me3 demethylases. CBFA2T2 does not bind the H3.3K27M decorated chromatin in vivo, thus the K to M mutation, partially compromises the CBFA2T2 repressive function. However, over-expressing CBFA2T2 rescues the low H3K27me3 level in H3.3K27M mNSC and H3.3K27M DIPG cells, thus suppressing the H3.3K27M tumor growth. Our findings suggest a new mechanism, which may contribute to the low H3K27me3 level observed in the H3K27M cells, and provide a new strategy for H3K27M therapy through manipulation of CBFA2T2.
Project description:Histone H3.1/3.2K27M and H3.3K27M mutation are driver mutations frequently identified in diffuse midline glioma (DMG). However, the precise mechanism by which H3K27M mediates tumorigenesis remains incompletely understood. By carrying out bait Protein-Protein Interaction followed by genome-wide screening (bPPI-seq) in H3.3WT and H3.3K27M mouse NSC models, we identified a novel histone reader CBFA2T2, which recognizes non-mutated or un-modified histone H3K27. Importantly, CBFA2T2 binding to H3K27, mediated by the NHR2 domain, is abrogated by the H3K27M oncogenic mutation. In H3.3 wildtype cells, CBFA2T2 represses transcription of genes involved in carbon metabolism and TCA cycle through its binding to H3K27. This alters the α-KG/Succinate (alpha-ketoglutarate/ Succinate) ratio and indirectly impacts H3K27me3 level, possibly through affecting the H3K27me3 demethylases. CBFA2T2 does not bind the H3.3K27M decorated chromatin in vivo, thus the K to M mutation, partially compromises the CBFA2T2 repressive function. However, over-expressing CBFA2T2 rescues the low H3K27me3 level in H3.3K27M mNSC and H3.3K27M DIPG cells, thus suppressing the H3.3K27M tumor growth. Our findings suggest a new mechanism, which may contribute to the low H3K27me3 level observed in the H3K27M cells, and provide a new strategy for H3K27M therapy through manipulation of CBFA2T2.
Project description:Histone H3.1/3.2K27M and H3.3K27M mutation are driver mutations frequently identified in diffuse midline glioma (DMG). However, the precise mechanism by which H3K27M mediates tumorigenesis remains incompletely understood. By carrying out bait Protein-Protein Interaction followed by genome-wide screening (bPPI-seq) in H3.3WT and H3.3K27M mouse NSC models, we identified a novel histone reader CBFA2T2, which recognizes non-mutated or un-modified histone H3K27. Importantly, CBFA2T2 binding to H3K27, mediated by the NHR2 domain, is abrogated by the H3K27M oncogenic mutation. In H3.3 wildtype cells, CBFA2T2 represses transcription of genes involved in carbon metabolism and TCA cycle through its binding to H3K27. This alters the α-KG/Succinate (alpha-ketoglutarate/ Succinate) ratio and indirectly impacts H3K27me3 level, possibly through affecting the H3K27me3 demethylases. CBFA2T2 does not bind the H3.3K27M decorated chromatin in vivo, thus the K to M mutation, partially compromises the CBFA2T2 repressive function. However, over-expressing CBFA2T2 rescues the low H3K27me3 level in H3.3K27M mNSC and H3.3K27M DIPG cells, thus suppressing the H3.3K27M tumor growth. Our findings suggest a new mechanism, which may contribute to the low H3K27me3 level observed in the H3K27M cells, and provide a new strategy for H3K27M therapy through manipulation of CBFA2T2.