Project description:Nuclear receptor-binding SET domain protein 1 (NSD1) prototype is a family of mammalian histone methyltransferases (NSD1, NSD2/MMSET/WHSC1, NSD3/WHSC1L1) that are essential in development and are mutated in human acute myeloid leukemia (AML), overgrowth syndromes, multiple myeloma and lung cancers. In AML, the recurring t(5;11)(q35;p15.5) translocation fuses NSD1 to nucleoporin-98 (NUP98). Here, we present the first characterization of the transforming properties and molecular mechanisms of NUP98-NSD1. We demonstrate that NUP98-NSD1 induces AML in vivo, sustains self-renewal of myeloid stem cells in vitro, and enforces expression of the HoxA7, HoxA9, HoxA10 and Meis1 proto-oncogenes. Mechanistically, NUP98-NSD1 binds genomic elements adjacent to HoxA7 and HoxA9, maintains histone H3 Lys 36 (H3K36) methylation and histone acetylation, and prevents EZH2-mediated transcriptional repression of the Hox-A locus during differentiation. Deletion of the NUP98 FG-repeat domain, or mutations in NSD1 that inactivate the H3K36 methyltransferase activity or that prevent binding of NUP98-NSD1 to the Hox-A locus precluded both Hox-A gene activation and myeloid progenitor immortalization. We propose that NUP98-NSD1 prevents EZH2-mediated repression of Hox-A locus genes by colocalizing H3K36 methylation and histone acetylation at regulatory DNA elements. This report is the first to link deregulated H3K36 methylation to tumorigenesis and to link NSD1 to transcriptional regulation of the Hox-A locus. Experiment Overall Design: Total RNA was extracted from stably transformed progenitors cultured in vitro and the expression levels of mRNA transcripts quantified using the Affymetrix GeneChip Mouse Genome 430 2.0 array, as previously described. The GEO database accession numbers: for progenitors immortalized by HoxA9 (GSM190542, GSM190546, GSM190547); for progenitors immortalized by coexpressed HoxA9 plus Meis1 (GSM190548, GSM190549, GSM190550); for progenitors immortalized by NUP98-NSD1 (GSM190551, GSM190552, GSM190553); and for progenitors immortalized by MLL-ENL (GSM190554). Experiment Overall Design: NOTE: CEL files and dChip data were requested by GEO but not provided.
Project description:Nuclear receptor-binding SET domain protein 1 (NSD1) prototype is a family of mammalian histone methyltransferases (NSD1, NSD2/MMSET/WHSC1, NSD3/WHSC1L1) that are essential in development and are mutated in human acute myeloid leukemia (AML), overgrowth syndromes, multiple myeloma and lung cancers. In AML, the recurring t(5;11)(q35;p15.5) translocation fuses NSD1 to nucleoporin-98 (NUP98). Here, we present the first characterization of the transforming properties and molecular mechanisms of NUP98-NSD1. We demonstrate that NUP98-NSD1 induces AML in vivo, sustains self-renewal of myeloid stem cells in vitro, and enforces expression of the HoxA7, HoxA9, HoxA10 and Meis1 proto-oncogenes. Mechanistically, NUP98-NSD1 binds genomic elements adjacent to HoxA7 and HoxA9, maintains histone H3 Lys 36 (H3K36) methylation and histone acetylation, and prevents EZH2-mediated transcriptional repression of the Hox-A locus during differentiation. Deletion of the NUP98 FG-repeat domain, or mutations in NSD1 that inactivate the H3K36 methyltransferase activity or that prevent binding of NUP98-NSD1 to the Hox-A locus precluded both Hox-A gene activation and myeloid progenitor immortalization. We propose that NUP98-NSD1 prevents EZH2-mediated repression of Hox-A locus genes by colocalizing H3K36 methylation and histone acetylation at regulatory DNA elements. This report is the first to link deregulated H3K36 methylation to tumorigenesis and to link NSD1 to transcriptional regulation of the Hox-A locus. Keywords: expression analysis
Project description:The NUP98::NSD1 fusion gene is associated with extremely poor prognosis in patients with acute myeloid leukemia (AML). NUP98::NSD1 induces self-renewal and blocks differentiation of hematopoietic stem cells, leading to leukemia development. Despite its association with poor prognosis, targeted therapy for NUP98::NSD1-positive AML is lacking, as the details of NUP98::NSD1 function are unknown. Here, we generated 32D cells (a murine interleukin-3 (IL-3)-dependent myeloid progenitor cell line) expressing mouse Nup98::Nsd1 to explore the function of NUP98::NSD1 in AML, including by comprehensive gene expression analysis. We identified two properties of Nup98::Nsd1+ 32D cells in vitro: first, Nup98::Nsd1 promoted blocking of AML cell differentiation, consistent with a previous report; second, Nup98::Nsd1 increased dependence on IL-3 for cell proliferation, due to overexpression of the alpha subunit of the IL-3 receptor (IL3-RA, also known as CD123). Consistent with our in vitro data, IL3-RA was also up-regulated in samples from patients with NUP98::NSD1-positive AML. These results highlight CD123 as a potential new therapeutic target in NUP98::NSD1-positive AML.
Project description:Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy driven largely by gene mutations and epigenetic modifications. The Nucleoporin 98kDa (NUP98) gene is a component of the nuclear pore complex that also plays a role as an intranuclear transcription scaffold. Fusion genes involving NUP98 have been recognized in a wide array of hematologic malignancy, most commonly AML4. Among over 30 partner genes known to be fused to NUP98 in human leukemia, NSD1 (for Nuclear receptor-binding SET Domain protein 1) (NSD1) is the most common. Patients with NUP98::NSD1 gene fusions have a poor prognosis, and the leukemic blasts frequently have an internal tandem duplication (ITD) of the FMS-related tyrosine kinase 3 gene (FLT3) gene accompanying the NUP98::NSD1 fusion. Previous reports have utilized BM transduction with retroviral vectors followed by transplantation into recipient mice to model AML driven by a NUP98::NSD1 fusion. Given that genetically engineered mice offer certain advantages over retroviral transduction models, such as consistent transgene expression and integration effects, lack of ionizing radiation, and transferability between investigators, we generated NUP98::Nsd1 transgenic mice.
Project description:NUP98-NSD1 positive Acute myeloid leukemia (AML) frequently occurs within the pediatric karyotypic normal(CN)-AML cohort. It is often associated with mutations in genes like FLT3, NRAS, WT1 and MYC. Here we have studied the role of NUP98-NSD1 fusion and NRASG12D in leukemia initiation and progression.
Project description:To provide the first insight into the pathophysiological relevance of the Nizp1-NSD1 functional association, we targeted this interaction in the context of acute myeloid leukemia driven by the expression of NUP98-NSD1 oncogenic fusion. We expressed NUP98-NSD1 in mouse c-Kit+/Sca-1+/Lin- bone marrow progenitors and knocked down Nizp1 expression by shRNA. We then performed gene expression profiling analysis using data obtained from RNA-seq of 4 different cell lines.
Project description:Development of cancer is intimately associated with genetic abnormalities that target proteins with intrinsically disordered regions (IDRs). In human hematological malignancies, recurrent chromosomal translocation of nucleoporin (NUP98 or NUP214) generates an aberrant chimera that invariably retains nucleoporin’s IDR, tandemly dispersed phenylalanine-andglycine (FG) repeats1-3. However, it remains largely elusive how unstructured IDRs contribute to oncogenesis. We here show that IDR or FG repeats harbored within NUP98-HOXA9, a homeodomain-containing transcription factor (TF) chimera recurrently detected in acute leukemia patients1,4,5, is essential for establishing nuclear liquid-liquid phase separation (LLPS) puncta and for inducing leukemic transformation of primary hematopoietic cells in vitro and in vivo. Strikingly, LLPS of NUP98-HOXA9 not only promotes chromatin occupancy of chimera TF oncoproteins but is also required for formation of a broad, ‘super-enhancer’-like binding pattern, typically seen at a battery of leukemia-related loci exemplified by HOX, MEIS and PBX genes, potentiating their transcriptional activation. An artificial HOX chimera, created by replacing NUP98’s FG repeats with an unrelated LLPSforming IDR of FUS6,7, had similar enhancement effects on chimera’s chromatin binding and target gene activation. Via Hi-C mapping, we further demonstrated that the phase-separated NUP98-HOXA9 protein assembly is able to induce formation of CTCF-independent chromatin looping enriched at leukemic oncogenes. Together, this report describes a proof-of-principle example wherein cancer acquires mutation to establish condensates of oncogenic TFs via a phase separation mechanism, which simultaneously enhances their chromatin targeting and induces organization of aberrant three-dimensional chromatin structure during tumorous transformation. As a range of LLPS-competent molecules are implicated in various human cancers, this mechanism can potentially be generalized to many malignant and diseased settings.
Project description:By performing biotin-mediated chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq) for two different NUP98 fusions, we defined the genome-wide direct binding sites of NUP98-HOXA9 or NUP98-HOXD13. To test whether NUP98 fusions and Mll1 were recruited to the same region of Hox genes promoters, Mll1 ChIP-seq analysis was carried out in murine NUP98-HOXA9 transformed cells using an anti-Mll1n antibody. In agreement with our results showing that NUP98-HOXA9 interacts with MLL1 in NSL/MLL1 complex, Mll1 binding targets significantly overlap with that of NUP98-HOXA9 at promoter region and gene body region. Given that MOF and MLL1 work in concert to modify H4K16ac and H3K4me3 at promoters, we further test whether H3K4me3 and H4K16ac marks are associated with NUP98-HOXA9-bound targets in murine NUP98-HOXA9 transformed cells by anti-H3K4me3 and anti-H4K16ac ChIP-seq. Our data show that both H3K4me3 and H4K16ac mark presents on NUP98-HOXA9 binding targets at promoters, and this is in line with the coordination role in the activities between MOF-mediated H4K16 acetylation and MLL/SET-mediated H3K4 methylation. In summary, our results confirmed that NUP98-HOXA9 and Mll1 are recruited to the same Hox loci, and this recruitment is associated with activating epigenetic marks, supporting the notion of the association between NUP98 fusions and NSL/Mll1 complex, suggesting that the recruitment of NUP98 fusions to the Hox gene loci maybe through MLL1.
Project description:Histone tails are post-translationally modified at multiple sites, including Lys36 on histone H3 (H3K36). The H3K36 methylation has been shown to associate with the transcription of active euchromatin, alternative splicing, DNA repair and recombination. However, the role of H3K36 methylation during cell differentiation is still obscure.Previous investigations found that a site specific Lys-to-Met mutation on histones can serve as an inhibitor of this site specific methyltransferases to repress global methylation on that lysine of histones. In this study we usedH3K36 Lys-to-Met mutant (H3K36M) as a tool to investigaterole of H3K36 methylation in our cell differentiation system. Expression of H3K36M repressed global H3K36 methylation but increased H3K27me3 as previously reported. On our cell differentiation system, H3K36M suppressed adipogenesis and myogenesis. Our pioneer RNA-seqstudy further showed that H3K36M repressed the expression of master regulator genes. Here, we did ChIP-seq of several histone modifications to further explore the changes on the epigenome by expression of H3K36M. Interestingly, on some important master regulator genes loci, the repressive marker H3K27me3 increased significantly, correlated with the repression on their expression. The H3K36M decreases global H3K36 di- and tri-methylation. To clarify which H3K36 methyltransferase is important for cell differentiation, we knocked down H3K36 di-methyltransferases Nsd1 and Nsd2, H3K36 tri-methyltransferase Setd2 separately. Nsd2 knockdown, but not Nsd1 or Setd2,can phenocopythe adipogenesis defect in H3K36M expressed cells.Comparing in RNA-seq results, Nsd2 knockdown cells showed similar gene expression profile with H3K36M expressed cells in adipogenesis. These suggest that Nsd2-mediated H3K36me2 plays an important role in adipogenesis.To study the role of H3K36 methylation in vivo, we generated an aP2 promoter driven H3K36M expressed transgenic mouse (Tg), to express H3K36M specifically in adipose tissue. The Tg mice showedsignificant dysfunction in both white and brown adipose tissues. Their fat tissues gene expression profile changed significantly. All of these indicate that H3K36 methylation is important for adipose tissue developmentin vivo.Together, our comprehensive studies provide novel insights into dynamics of H3K36 methylation and its important role in transcriptional regulation of cell differentiation and mouse fat tissue development.