SRSF2 mutations impair hematopoiesis and alter exon recognition
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Janine Ilagan
PROVIDER: E-GEOD-65349 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Mutations within genes encoding spliceosomal proteins are the most common class of mutations in patients with myelodysplastic syndromes, yet it is currently not well understood how these mutations impact hematopoiesis or RNA splicing. Here we report that mutations affecting the splicing factor SRSF2 alter its normal RNA recognition activity, resulting in impaired hematopoietic differentiation and myelodysplasia. Commonly occurring SRSF2 mutations impaired wildtype SRSF2’s normal RNA-binding avidity and preference for specific exonic splicing enhancer RNA motifs. Integration of murine and human transcriptome data identified recurrent mis-splicing of key transcriptional regulators in the presence of mutant SRSF2, including promotion of a highly conserved “poison” exon of EZH2 that results in nonsense-mediated decay and contributes to impaired hematopoiesis. These data provide a mechanistic basis for the enrichment of specific mutations in spliceosomal proteins in myelodysplasia, and suggest that altered RNA recognition activity is a novel mechanism of leukemogenesis.
2015-05-12 | GSE65349 | GEO
Project description:Mutations in spliceosomal genes are commonly found in patients with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). These mutations occur at highly restricted amino acid residues and perturb normal splice site and exon recognition. Spliceosomal mutations are always heterozygous and rarely co-occur with one another, suggesting that cells may only tolerate a partial deviation from normal splicing activity. To test this hypothesis, we generated mice with inducible hemizygous expression of the commonly occurring SRSF2P95H mutation in the hematopoietic system. These mice rapidly developed lethal bone marrow failure upon activation of the Srsf2P95H mutation with concomitant deletion of the wildtype Srsf2 allele, demonstrating that Srsf2-mutant cells depend on the wildtype Srsf2 allele for survival. We next tested whether spliceosomal-mutant leukemias display greater sensitivity to pharmacologic splicing inhibition induced by the small molecule E7107. Treatment of isogenic murine leukemias as well as patient-derived xenograft (PDX) AMLs showed significant reductions in leukemic burden specifically in samples carrying spliceosomal mutations. Collectively, these data provide genetic and pharmacologic evidence that leukemias with spliceosomal mutations are preferentially susceptible to additional splicing perturbations in vivo compared with wildtype counterparts. Modulation of spliceosome function may provide a novel therapeutic avenue in genetically defined subsets of MDS/AML patients. We created an isogenic murine leukemia model by retroviral overexpression of the MLL-AF9 fusion oncogene in Vav-Cre Srsf2+/+ or Vav-Cre Srsf2P95H/+ BM cells followed by transplantation into lethally irradiated recipient mice. In order to determine the mechanistic origins of the Srsf2 mutant-selective effects of E7107, we analyzed transcriptional changes after five consecutive days of E7107 or vehicle treatment in vivo. GFP+ Cd11b+ cells were purified from the BM of recipient mice exactly three hours after the last dose of E7107 and were subjected to paired-end 2x50bp RNA-seq. For the knock-in/knock-out experiments, we generated inducible, hemizygous Srsf2P95H mice to study the effects of wildtype Srsf2 deletion with concomitant activation of the Srsf2P95H allele. Mx1-cre Srsf2fl/+ mice were crossed to Srsf2P95H/+ mice to generate Srsf2 wildtype (Mx1-cre Srsf2+/+), Srsf2 heterozygous knockout (Mx1-Cre Srsf2+/-), Srsf2 heterozygous P95H mutant (Mx1-Cre Srsf2P95H/+), and Srsf2 hemizygous P95H mutant (Mx1-Cre Srsf2P95H/-) mice, which were subjected to single-end 101bp RNA-seq.
2016-03-31 | E-GEOD-74064 | biostudies-arrayexpress
Project description:Whole-exome sequencing studies have identified common mutations affecting genes encoding components of the RNA splicing machinery in hematological malignancies. Here, we sought to determine how mutations affecting the 3' splice site recognition factor U2AF1 altered its normal role in RNA splicing. We find that U2AF1 mutations influence the similarity of splicing programs in leukemias, but do not give rise to widespread splicing failure. U2AF1 mutations cause differential splicing of hundreds of genes, affecting biological pathways implicated in myeloid disease such as DNA methylation (DNMT3B), X chromosome inactivation (H2AFY), the DNA damage response (ATR, FANCA), and apoptosis (CASP8). We show that U2AF1 mutations alter the preferred 3' splice site motif in vivo, in cell culture, and in vitro. Mutations affecting the first and second zinc fingers give rise to different alterations in splice site preference and largely distinct downstream splicing programs. These allele-specific effects are consistent with a computationally predicted model of U2AF1 in complex with RNA. Our findings suggest that U2AF1 mutations contribute to pathogenesis by causing quantitative changes in splicing that affect diverse cellular pathways, and give insight into the normal function of U2AF1’s zinc finger domains. mRNA profiles of K562 cells expressing U2AF1 WT, mutants and knockdown of U2AF1 generated by deep sequencing.
2014-09-23 | E-GEOD-58871 | biostudies-arrayexpress
Project description:Mutations in genes encoding splicing factors (which we refer to as spliceosomal genes) are commonly found in patients with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). These mutations recurrently affect specific amino acid residues, leading to perturbed normal splice site and exon recognition. Spliceosomal gene mutations are always heterozygous and rarely occur together with one another, suggesting that cells may tolerate only a partial deviation from normal splicing activity. To test this hypothesis, we engineered mice to express a mutated allele of serine/arginine-rich splicing factor 2 (Srsf2P95H) - which commonly occurs in individuals with MDS and AML - in an inducible, hemizygous manner in hematopoietic cells. These mice rapidly succumbed to fatal bone marrow failure, demonstrating that Srsf2-mutated cells depend on the wild-type Srsf2 allele for survival. In the context of leukemia, treatment with the spliceosome inhibitor E7107 resulted in substantial reductions in leukemic burden, specifically in isogenic mouse leukemias and patient-derived xenograft AMLs carrying spliceosomal mutations. Whereas E7107 treatment of mice resulted in widespread intron retention and cassette exon-skipping in leukemic cells regardless of Srsf2 genotype, the magnitude of splicing inhibition following E7107 treatment was greater in Srsf2-mutated than in Srsf2-wild-type leukemia, consistent with the differential effect of E7107 on survival. Collectively, these data provide genetic and pharmacologic evidence that leukemias with spliceosomal gene mutations are preferentially susceptible to additional splicing perturbations in vivo as compared to leukemias without such mutations. Modulation of spliceosome function may thus provide a new therapeutic avenue in genetically defined subsets of individuals with MDS or AML.
2016-03-31 | GSE74064 | GEO
Project description:Mutations in the splicing factor Serine Arginine Rich Splicing Factor 2 (SRSF2) occur in over 30% of patients with myelodysplasia (MDS) and a subset of patients with acute myeloid leukemia (AML) and portend a poor prognosis. SRSF2 is ubiquitously expressed and directs exon inclusion or exclusion in a sequence and context dependent manner. SRSF2 mutations almost exclusively affect the proline at position 95 in the C-terminus of the RNA binding domain. We here show how a mutation in SRSF2 (P95H) affects its normal function in vivo on a transcriptome-wide basis via RNA crosslinking and immunoprecipitation (HITS-CLIP) and parallel quantification of transcript levels (RNA-seq), leading to the identification of differentially bound and alternatively spliced SRSF2 targets. Keywords: Splicing, myeloid neoplasia, SRSF2, HITS-CLIP
2018-06-18 | GSE111900 | GEO
Project description:RNA splicing factor mutations constitute the most common class of alterations in myelodysplastic syndromes (MDS). These occur as heterozygous mutations at restricted residues in SF3B1, SRSF2, and U2AF1 in a mutually exclusive manner. The mutual exclusivity of spliceosomal mutations suggests synthetic lethal and/or convergent biological effects of these mutations; however, there is currently no functional evidence supporting either of these possibilities. Here we report that spliceosomal mutations, despite imparting distinct alterations on gene expression and splicing, are negatively selected for when co-expressed in the same cell or in a homozygous state. Co-expression of these mutations results in additive, rather than synergistic, effects on RNA splicing mechanisms. Despite disparate global effects on splicing, aberrant splicing of distinct kinases by mutant SF3B1 and SRSF2 results in hyperactivated NF-κB signaling. These data identify convergent biological consequences of splicing factor mutations and the functional basis for the mutual exclusivity and heterozygous nature of these mutations.
2018-08-13 | GSE97452 | GEO
Project description:Recurrent mutations in the splicing factors SRSF2 and SF3B1 are common in myelodysplasia (MDS) and acute myeloid leukemia (AML). These mutations are invariably heterozygous, as cells with splicing factor mutations nevertheless depend on wild-type splicing activity. Disrupting splicing further is lethal, suggesting a therapeutic vulnerability for splicing factor mutant hematopoietic neoplasms. Glycogen synthase kinase-3 (GSK-3) phosphorylates multiple splicing factors, including SRSF2 and SF3B1, and regulates the splicing of a broad range of mRNAs in human cells. Inhibition of GSK-3 disrupts splicing and promotes cell death in hematopoietic cells with heterozygous mutations in SRSF2 or SF3B1 and not in cells with wild-type splicing factors. To characterize how GSK-3 inhibition alters splicing and leads to cell death in SRSF2P95H/+ and SF3B1K700E/+ cells, we have performed deep RNA sequencing on K562 cells with SRSF2P95H/+ or SF3B1K700E/+ knocked into the endogenous locus (provided by Omar Abdel-Wahab (Wang et al; PMID 30799057) and treated with the GSK-3 inhibitor CHIR99021. Parental cells with wild-type splicing factors were included as controls. RNA-Seq data were further analyzed through the rMATS pipeline to assess changes in mRNA splicing (Liu et al, 2023).
2023-06-28 | GSE235600 | GEO
Project description:Substantial effort is currently devoted to identifying cancer-associated alterations using genomics. Here, we show that standard blood collection procedures rapidly change the transcriptional and post-transcriptional landscapes of hematopoietic cells, resulting in biased activation of specific biological pathways, up-regulation of pseudogenes, antisense RNAs, and unannotated coding isoforms, and RNA surveillance inhibition. Affected genes include common mutational targets and thousands of other genes participating in processes such as chromatin modification, RNA splicing, T and B cell activation, and NF-κB signaling. The majority of published leukemic transcriptomes exhibit signals of this incubation-induced dysregulation, explaining up to 40% of differences in gene expression and alternative splicing between leukemias and reference normal transcriptomes. The effects of sample processing are particularly evident in pan-cancer analyses. We provide biomarkers that detect prolonged incubation of individual samples, and show that keeping blood on ice markedly reduces changes to the transcriptome. In addition to highlighting the potentially confounding effects of technical artifacts in cancer genomics data, our study emphasizes the need to survey the diversity of normal as well as neoplastic cells when characterizing tumors. This study is complemented by GSE61410: transcriptomic profiling of bone marrow cells from healthy individuals. Peripheral blood mononuclear cells (PBMCs) were isolated from four healthy individuals, following an ex vivo incubation of variable length at either room temperature or on ice. RNA transcriptomes were measured using the Illumina HiSeq.
2014-10-27 | E-GEOD-58335 | biostudies-arrayexpress
Project description:We report the biological function of Srsf2 in hematopoiesis in conditional knockout mouse models. Ablation of Srsf2 in the hematopoietic lineage caused embryonic lethality, and Srsf2-deficient fetal liver cells showed significantly enhanced apoptosis and decreased hematopoietic stem/progenitor cells. Induced ablation of Srsf2 in adult Mx1Cre/ Srsf2flox/flox mice upon polyinosinic:polycytidylic acid injection demonstrated a significant decrease in lineage-/Sca+/cKit+ cells in bone marrow. To reveal the functional impact of MDS-associated mutations in SRSF2, we profiled global splicing responses on an MDS-L cell line using RASL-seq, and found that the P95H missense mutation and P95 to R102 in-frame 8 amino-acid deletion caused significant changes in alternative splicing. The affected genes were enriched in cancer development and apoptosis. These findings suggest that intact Srsf2 is essential for the functional integrity of the hematopoietic system, and its mutations are likely key driver events to MDS. MDS-L cells (in triplicate) were transfected by srsf2 shRNA only, or pTRIPZ vectors containing both srsf2 shRNA and srsf2 mutants cDNA including P95H and P95 8 amino acid deletion as well as wild-type construct, followed by Dox induction. Total RNAs were extracted and been analyzed by RASL-seq.
2015-03-01 | E-GEOD-61052 | biostudies-arrayexpress
Project description:SRSF2 is an RNA binding protein that plays important roles in splicing of mRNA precursors. Mutations in SRSF2 are frequently found in patients with myelodysplastic syndromes and certain leukemias, but how they affect SRSF2 function has only begun to be examined. Here we used CRISPR/Cas9 to introduce the P95H mutation to SRSF2 in K562 leukemia cells, generating an isogenic model so that splicing alterations can be attributed solely to mutant SRSF2. We found that SRSF2 (P95H) misregulates 548 splicing events (<1% of total). Of these, 374 involve the inclusion of cassette exons, and the inclusion was either increased (206) or decreased (168). We detected a specific motif (UCCA/UG) enriched in the more included exons and a distinct motif (UGGA/UG) in the more excluded exons. RNA gel shift assays showed that a mutant SRSF2 derivative bound more tightly than its wild-type counterpart to RNA sites containing UCCAG, but less tightly to UGGAG sites. The pattern of exon inclusion or exclusion thus correlated in most cases with stronger or weaker RNA binding, respectively. We further show that the P95H mutation does not affect other functions of SRSF2, i.e., protein-protein interactions with key splicing factors. Our results thus demonstrate that the P95H mutation positively or negatively alters the binding affinity of SRSF2 for cognate RNA sites in target transcripts, leading to misregulation of exon inclusion. Our findings not only shed light on the mechanism of the disease-associated SRSF2 mutation in splicing regulation, but also reveal a group of mis-spliced mRNA isoforms for potential therapeutic targeting. Examination of differentially spliced events in K562 CRISPR cell clones (with wild-type or mutant SRSF2) by RNA sequencing
2015-08-10 | E-GEOD-71299 | biostudies-arrayexpress