Clinical presentation and differential splicing of SRSF2, U2AF1 and SF3B1 mutations in patients with Acute Myeloid Leukemia
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PROVIDER: PRJNA609654 | ENA |
REPOSITORIES: ENA
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Project description:Previous studies demonstrated that splicing factor mutations are recurrent events in hematopoietic malignancies with both clinical and functional implications. However, their aberrant splicing patterns in acute myeloid leukemia remain largely unexplored. In this study we characterized mutations in SRSF2, U2AF1 and SF3B1, the most commonly mutated splicing factors. In our clinical analysis of 2678 patients, splicing factor mutations showed inferior relapse-free and overall survival, however, these mutations did not represent independent prognostic markers. RNA-sequencing of 246 and independent validation in 177 patients revealed an isoform expression profile highly characteristic for each individual mutation, with several isoforms showing a strong dysregulation. By establishing a custom differential splice junction usage pipeline, we accurately detected aberrant splicing in splicing factor mutated samples. A large proportion of differentially used junctions were novel, including several junctions in leukemia associated genes. In SRSF2(P95H) mutants we further explored the possibility of a cascading effect through the dysregulation of the splicing pathway. Furthermore, we observed a validated impact on overall survival for two junctions overused in SRSF2(P95H) mutants. We conclude that splicing factor mutations do not represent independent prognostic markers. However, they do have genome-wide consequences on gene splicing leading to dysregulated isoform expression of several genes
2020-05-24 | GSE146173 | GEO
Project description:Myelodysplastic syndromes (MDS) with mutated SF3B1 gene have many features including a favorable outcome that are distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we show that SF3B1-mutated MDS are characterized by a dramatically reduced R-loop formation predominating in gene bodies, which tightly associates with reduced retention of introns specifically found in SF3B1-mutated, but not in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibited augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation, which were recapitulated in murine Sf3b1K700E/+ proerythroblasts. Importantly, R-loop formation was restored by histone deacetylase inhibition using SAHA/vorinostat, which improved Sf3b1K700E/+ erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress is a hallmark of SF3B1- mutated MDS ineffective erythropoiesis, which could be used as a new therapeutic target.
2024-04-08 | PXD038700 | Pride
Project description:Myelodysplastic syndromes (MDS) with mutated SF3B1 gene have many features including a favorable outcome that are distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we show that SF3B1-mutated MDS are characterized by a dramatically reduced R-loop formation predominating in gene bodies, which tightly associates with reduced retention of introns specifically found in SF3B1-mutated, but not in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibited augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation, which were recapitulated in murine Sf3b1K700E/+ proerythroblasts. Importantly, R-loop formation was restored by histone deacetylase inhibition using SAHA/vorinostat, which improved Sf3b1K700E/+ erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress is a hallmark of SF3B1- mutated MDS ineffective erythropoiesis, which could be used as a new therapeutic target.
2024-05-29 | PXD038656 | Pride
Project description:Myelodysplastic syndromes (MDS) with mutated SF3B1 gene have many features including a favorable outcome that are distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we show that SF3B1-mutated MDS are characterized by a dramatically reduced R-loop formation predominating in gene bodies, which associates with intron retention reduction specifically found in SF3B1-mutated, but not in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibited augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation. Importantly, histone deacetylase inhibition using vorinostat restored Rloop formation,slowed down DNA replication forks and improved SF3B1-mutated erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress is a hallmark of SF3B1-mutated MDS ineffective erythropoiesis, which could be used as a new therapeutic target.
2024-02-22 | GSE220525 | GEO
Project description:Myelodysplastic syndromes (MDS) with mutated SF3B1 gene have many features including a favorable outcome that are distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we show that SF3B1-mutated MDS are characterized by a dramatically reduced R-loop formation predominating in gene bodies, which associates with intron retention reduction specifically found in SF3B1-mutated, but not in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibited augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation. Importantly, histone deacetylase inhibition using vorinostat restored Rloop formation,slowed down DNA replication forks and improved SF3B1-mutated erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress is a hallmark of SF3B1-mutated MDS ineffective erythropoiesis, which could be used as a new therapeutic target.
2024-02-22 | GSE220523 | GEO
Project description:Myelodysplastic syndromes (MDS) with mutated SF3B1 gene have many features including a favorable outcome that are distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we show that SF3B1-mutated MDS are characterized by a dramatically reduced R-loop formation predominating in gene bodies, which associates with intron retention reduction specifically found in SF3B1-mutated, but not in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibited augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation. Importantly, histone deacetylase inhibition using vorinostat restored Rloop formation,slowed down DNA replication forks and improved SF3B1-mutated erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress is a hallmark of SF3B1-mutated MDS ineffective erythropoiesis, which could be used as a new therapeutic target.
2024-02-22 | GSE220516 | GEO
Project description:Myelodysplastic syndromes (MDS) with mutated SF3B1 gene have many features including a favorable outcome that are distinct from MDS with mutations in other splicing factor genes SRSF2 or U2AF1. Molecular bases of these divergences are poorly understood. Here we show that SF3B1-mutated MDS are characterized by a dramatically reduced R-loop formation predominating in gene bodies, which tightly associates with reduced retention of introns specifically found in SF3B1-mutated, but not in U2AF1- or SRSF2-mutated MDS. Compared to erythroblasts from SRSF2- or U2AF1-mutated patients, SF3B1-mutated erythroblasts exhibited augmented DNA synthesis, accelerated replication forks, and single-stranded DNA exposure upon differentiation, which were recapitulated in murine Sf3b1K700E/+ proerythroblasts. Importantly, R-loop formation was restored by histone deacetylase inhibition using SAHA/vorinostat, which improved Sf3b1K700E/+ erythroblast differentiation. In conclusion, loss of R-loops with associated DNA replication stress is a hallmark of SF3B1- mutated MDS ineffective erythropoiesis, which could be used as a new therapeutic target.
2024-02-22 | GSE220271 | GEO
Project description:Recurrent mutations in RNA splicing factors SF3B1, U2AF1, and SRSF2 have been reported in hematologic cancers including myelodysplastic syndromes (MDS) and chronic lymphocytic leukemia (CLL). However, SF3B1 is the only splicing associated gene to be found mutated in CLL and has been shown to induce aberrant splicing. To investigate if any other genomic aberration caused similar transcriptome changes, we clustered RNASeq samples based on an alternative 3’ splice site (ss) pattern previously identified in SF3B1-mutant CLL patients. Out of 215 samples, we identified 37 (17%) with alternative 3’ ss usage, the majority of which harbored known SF3B1 hotspot mutations. Interestingly, 3 patient samples carried previously unreported in-frame deletions in SF3B1 around K700, the most frequent mutation hotspot. To study the functional effects of these deletions, we used various minigenes demonstrating that recognition of canonical 3’ ss and alternative branchsite are required for aberrant splicing, as observed for SF3B1 p.K700E. The common mechanism of action of these deletions and substitutions result in similar sensitivity of primary cells towards splicing inhibitor E7107. Altogether, these data demonstrate that novel SF3B1 in-frame deletion events identified in CLL result in aberrant splicing, a common biomarker in spliceosome-mutant cancers.
2017-06-27 | GSE95352 | GEO
Project description:Myelodysplastic syndromes (MDS) are characterized by recurrent somatic alterations often affecting components of RNA splicing machinery. Mutations of splice factors SF3B1, SRSF2, ZRSR2 and U2AF1 occur in >50% of MDS. To assess the impact of spliceosome mutations on splicing and to identify common pathways/genes affected by distinct mutations, we performed RNA-sequencing of 24 MDS bone marrow samples harboring spliceosome mutations (including hotspot alterations of SF3B1, SRSF2 and U2AF1; small deletions of SRSF2 and truncating mutations of ZRSR2), and devoid of other common co-occurring mutations. We uncover the landscape of splicing alterations in each splice factor mutant MDS and demonstrate that SRSF2 deletions cause highest number of splicing alterations compared with other spliceosome mutations. Although the mis-spliced events observed in different splice factor mutations were largely non-overlapping, a subset of genes, including EZH2, were aberrantly spliced in multiple mutant groups. Pathway analysis revealed that the mis-spliced genes in different mutant groups were enriched in RNA splicing and transport as well as several signaling cascades, suggesting converging biological consequences downstream of distinct spliceosome mutations.
2019-11-07 | GSE128429 | GEO
Project description:Mutations in RNA splicing factor genes including SF3B1, U2AF1, SRSF2, and ZRSR2 have been reported to contribute to development of myeloid neoplasms including myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia (sAML). Chemical tools targeting cells carrying these mutant genes remain limited and underdeveloped. Among the four proteins, mutant U2AF1 (U2AF1mut) acquires an altered 3’ splice site selection preference and co-operates with the wild-type U2AF1 (U2AF1wt) to change various gene isoform patterns to support MDS cells survival and proliferation. U2AF1 mutations in MDS cells are always heterozygous and the cell viability is reduced when exposed to additional insult affecting U2AF1wt function. To investigate if the pharmacological inhibition of U2AF1wt function can provoke drug-induced vulnerability of cells harboring U2AF1mut, we conducted a fragment-based library screening campaign to discover compounds targeting the U2AF homology domain (UHM) in U2AF1 that is required for the formation of the U2AF1/U2AF2 complex to define the 3' splice site. The most promising hit (SF1-8) selectively inhibited growth of leukemia cell lines overexpressingU2AF1mut and human primary MDS cells carrying U2AF1mut. RNA-seq analysis of K562-U2AF1mut following treatment with SF1-8 further revealed alteration of isoform patterns for a set of proteins that impair or rescue pathways associated with endocytosis, intracellular vesicle transport, and secretion. Our data suggested that further optimization of SF1-8 is warranted to obtain chemical probes that can be used to evaluate the therapeutic concept of inducing lethality to U2AF1mut cells by inhibiting the U2AF1wt protein.
2024-06-28 | GSE267059 | GEO