A PRC2-KDM5B-stemness regulatory axis sustains tumorigenicity of acute myeloid leukemia [RNA-Seq]
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ABSTRACT: Acute myeloid leukemias (AMLs) with the NUP98-NSD1 or MLL gene rearrangement (MLL-r) share transcriptomic profiles featured with stemness-related gene signatures and display poor prognosis in the clinic. However, the molecular underpinnings of AML aggressiveness and stemness remain far from clear. Here, we report that the enzymatic activity of Polycomb Repressive Complex 2 (PRC2) is crucial for maintenance of tumorigenicity in NUP98-NSD1+ AML, consistent to its role in MLL-r AML. Transcriptomic analysis revealed Kdm5b, a lysine demethylase gene carrying the “bivalent domain” chromatin feature in AML, to be directly repressed by PRC2. While ectopic expression of Kdm5b suppressed AML growth, its depletion in AML not only promoted tumorigenicity but also significantly attenuated anti-AML effects by PRC2 inhibitors, thus demonstrating an involvement of the PRC2-|Kdm5b axis for AML oncogenesis. Lower KDM5B expression is positively correlated with poorer prognosis of human AML patients. RNA-seq, ChIP-seq and CUT&RUN based genomic profilings also showed that Kdm5b directly binds to and represses AML stemness genes. In contrast to an essential involvement for its various chromatin-associating domains, Kdm5b’s demethylase function was found to be dispensable for AML suppression, indicating a scaffold role in assembling gene-repressive complexes. Collectively, this study describes a molecular axis involving histone modifiers (PRC2 and Kdm5b) for sustaining the malignant features of AML, implicative of potential therapeutics.
Project description:Acute myeloid leukemias (AMLs) with the NUP98-NSD1 or MLL gene rearrangement (MLL-r) share transcriptomic profiles featured with stemness-related gene signatures and display poor prognosis in the clinic. However, the molecular underpinnings of AML aggressiveness and stemness remain far from clear. Here, we report that the enzymatic activity of Polycomb Repressive Complex 2 (PRC2) is crucial for maintenance of tumorigenicity in NUP98-NSD1+ AML, consistent to its role in MLL-r AML. Transcriptomic analysis revealed Kdm5b, a lysine demethylase gene carrying the “bivalent domain” chromatin feature in AML, to be directly repressed by PRC2. While ectopic expression of Kdm5b suppressed AML growth, its depletion in AML not only promoted tumorigenicity but also significantly attenuated anti-AML effects by PRC2 inhibitors, thus demonstrating an involvement of the PRC2-|Kdm5b axis for AML oncogenesis. Lower KDM5B expression is positively correlated with poorer prognosis of human AML patients. RNA-seq, ChIP-seq and CUT&RUN based genomic profilings also showed that Kdm5b directly binds to and represses AML stemness genes. In contrast to an essential involvement for its various chromatin-associating domains, Kdm5b’s demethylase function was found to be dispensable for AML suppression, indicating a scaffold role in assembling gene-repressive complexes. Collectively, this study describes a molecular axis involving histone modifiers (PRC2 and Kdm5b) for sustaining the malignant features of AML, implicative of potential therapeutics.
Project description:Acute myeloid leukemias (AMLs) with the NUP98-NSD1 or MLL gene rearrangement (MLL-r) share transcriptomic profiles featured with stemness-related gene signatures and display poor prognosis in the clinic. However, the molecular underpinnings of AML aggressiveness and stemness remain far from clear. Here, we report that the enzymatic activity of Polycomb Repressive Complex 2 (PRC2) is crucial for maintenance of tumorigenicity in NUP98-NSD1+ AML, consistent to its role in MLL-r AML. Transcriptomic analysis revealed Kdm5b, a lysine demethylase gene carrying the “bivalent domain” chromatin feature in AML, to be directly repressed by PRC2. While ectopic expression of Kdm5b suppressed AML growth, its depletion in AML not only promoted tumorigenicity but also significantly attenuated anti-AML effects by PRC2 inhibitors, thus demonstrating an involvement of the PRC2-|Kdm5b axis for AML oncogenesis. Lower KDM5B expression is positively correlated with poorer prognosis of human AML patients. RNA-seq, ChIP-seq and CUT&RUN based genomic profilings also showed that Kdm5b directly binds to and represses AML stemness genes. In contrast to an essential involvement for its various chromatin-associating domains, Kdm5b’s demethylase function was found to be dispensable for AML suppression, indicating a scaffold role in assembling gene-repressive complexes. Collectively, this study describes a molecular axis involving histone modifiers (PRC2 and Kdm5b) for sustaining the malignant features of AML, implicative of potential therapeutics.
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: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 characterized by serious aggressivity of high relapse risk and various molecular aberrations. Rearrangements involving NUP98 with multiple fusing partner genes in myeloid malignancies indicate dismal survival outcomes. Mechanisms contributing to subsequent aggressive progression and severe relapse risk of NUP98-rearranged AML remain undefined. Here we identified a novel oncogenic fusion RUNX1/ZNF423 in a relapse and refractory AML patient with NUP98/NSD1. And mice xenografted from the patient bearing both RUNX1/ZNF423 and NUP98/NSD1 display more severe engraftment levels than NUP98/NSD1 only. Mechanically, RUNX1/ZNF423 accompanied with NUP98/NSD1 recapitulated transcriptional signatures in hematopoietic differentiation blockage and altered amino acid metabolism pathway. Moreover, single-cell sequencing confirmed the coexistence of RUNX1/ZNF423 with NUP98/NSD1 in the same leukemic blast. Meanwhile, we also found that the coexistence of gene fusions in NUP98-rearranged AML was a significant phenomenon, which probably contributes to their worse clinical outcome. Finally, tailored intervention treatment based on ex vivo drug sensitivity testing is provided to this relapse and refractory AML patient and achieved favorable clinical response. Taken together, we not only identified a novel gene fusion RUNX1/ZNF423 with transforming potential detected in a NUP98-rearranged AML, but also achieved a deeper understanding into mechanisms contributing to disease relapse in AML.
Project description:Acute myeloid leukemia (AML) is characterized by serious aggressivity of high relapse risk and various molecular aberrations. Rearrangements involving NUP98 with multiple fusing partner genes in myeloid malignancies indicate dismal survival outcomes. Mechanisms contributing to subsequent aggressive progression and severe relapse risk of NUP98-rearranged AML remain undefined. Here we identified a novel oncogenic fusion RUNX1/ZNF423 in a relapse and refractory AML patient with NUP98/NSD1. And mice xenografted from the patient bearing both RUNX1/ZNF423 and NUP98/NSD1 display more severe engraftment levels than NUP98/NSD1 only. Mechanically, RUNX1/ZNF423 accompanied with NUP98/NSD1 recapitulated transcriptional signatures in hematopoietic differentiation blockage and altered amino acid metabolism pathway. Moreover, single-cell sequencing confirmed the coexistence of RUNX1/ZNF423 with NUP98/NSD1 in the same leukemic blast. Meanwhile, we also found that the coexistence of gene fusions in NUP98-rearranged AML was a significant phenomenon, which probably contributes to their worse clinical outcome. Finally, tailored intervention treatment based on ex vivo drug sensitivity testing is provided to this relapse and refractory AML patient and achieved favorable clinical response. Taken together, we not only identified a novel gene fusion RUNX1/ZNF423 with transforming potential detected in a NUP98-rearranged AML, but also achieved a deeper understanding into mechanisms contributing to disease relapse in AML.
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:We assessed lineage involvement by NUP98 translocations in myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and T-cell acute lymphoblastic leukemia (T-ALL). Single cell analysis by FICTION (Fluorescence Immunophenotype and Interphase Cytogenetics as a Tool for Investigation of Neoplasms) showed that NUP98-translocations with various partners, i.e. NSD1, DDX10, RAP1GDS1, and LNP1, always affected a CD34+/CD133+ hematopoietic precursor. Interestingly, in MDS/AML myelomonocytes, erythroid cells, B- and T- lymphocytes belonged to the abnormal clone, while in T-ALL only CD7+/CD3+ cells were involved. The partner did not appear to play a major role in determining the leukemia phenotype as shown in AML and T-ALL with the same NUP98-RAP1GDS1 fusion. Additional hits, namely mutations of FLT3 and CEBPA in MDS/AML and mutation of NOTCH1 plus MYB duplication in T-ALL, were identified in leukemias with, respectively, myeloid or T-lymphoid phenotype. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or peripheral blood samples. Copy number and Copy neutral LOH analysis of with Affymetrix Cytogenetic 2.7 and Cytoscan HD SNP arrays was performed on 6 NUP98 rearranged leukemias.
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: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.