Gene Expression Profiles Induced by RNA interference on NSD1 Δ5Δ7, and NSD1 Δ19–23 isoforms in Fibroblast Cells III.
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ABSTRACT: NSD1 Δ5Δ7, NSD1 Δ19–23 5’end and canonical NSD1 transcript are involved in cell cycle regulation and in tumoral and neoplastic development. Another NSD1 isoform AT2 target that might mediate the cellular division mechanisms is ARP3 actin-related protein 3 homolog B ACTR3B that may act downstream of the stress fibers and bundle of actin filaments formation
Project description:NSD1 Δ5Δ7, NSD1 Δ19–23 5’end and canonical NSD1 transcript are involved in cell cycle regulation and in tumoral and neoplastic development. Another NSD1 isoform AT2 target that might mediate the cellular division mechanisms is ARP3 actin-related protein 3 homolog B ACTR3B that may act downstream of the stress fibers and bundle of actin filaments formation
Project description:NSD1 Δ5Δ7, NSD1 Δ19–23 5’end and canonical NSD1 transcript are involved in cell cycle regulation and in tumoral and neoplastic development. Another NSD1 isoform AT2 target that might mediate the cellular division mechanisms is ARP3 actin-related protein 3 homolog B ACTR3B that may act downstream of the stress fibers and bundle of actin filaments formation
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:Sotos syndrome (SS) represents an important human model system for the study of epigenetic regulation; it is an overgrowth/intellectual disability syndrome caused by mutations in a histone methyltransferase, NSD1. As layered epigenetic modifications are often interdependent, we propose that pathogenic NSD1 mutations have a genome-wide impact on the most stable epigenetic mark, DNA methylation (DNAm). By interrogating DNAm in SS patients, we identify a genome-wide, highly significant NSD1+/- specific signature that differentiates pathogenic NSD1 mutations from controls, benign NSD1 variants and the clinically overlapping Weaver syndrome. Validation studies of independent cohorts of SS and controls assigned 100% of these samples correctly. This highly specific and sensitive NSD1+/- specific signature encompasses genes that function in cellular morphogenesis and neuronal differentiation, reflecting cardinal features of the SS phenotype. The identification of SS-specific genome-wide DNAm alterations will facilitate both the elucidation of the molecular pathophysiology of SS and the development of improved diagnostic testing. Bisulphite converted DNA from 122 samples were hybridized to the Illumina Infinium 450k Human Methylation Beadchip array.
Project description:Nuclear receptor binding SET domain protein 1 (NSD1) is recurrently mutated in human cancers including acute leukemia. We found that NSD1 knockdown altered erythroid clonogenic growth of human CD34+ hematopoietic cells. Ablation of Nsd1 in the hematopoietic system induced a transplantable erythroleukemia in mice. Despite abundant expression of the transcriptional master regulator GATA1, in vitro differentiation of Nsd1-/- erythroblasts was majorly impaired associated with reduced activation of GATA1-induced targets, while GATA1-repressed target genes were less affected. Retroviral expression of wildtype Nsd1, but not a catalytically-inactive Nsd1N1918Q SET-domain mutant induced terminal maturation of Nsd1-/- erythroblasts. Despite similar GATA1 levels, exogenous Nsd1 but not Nsd1N1918Q significantly increased GATA1 chromatin occupancy and target gene activation. Notably, Nsd1 expression reduced the association of GATA1 with the co-repressor SKI, and knockdown of SKI induced differentiation of Nsd1-/- erythroblasts. Collectively, we identified the NSD1 methyltransferase as a novel regulator of GATA1-controlled erythroid differentiation and leukemogenesis.
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.