Similar Datasets
Project description:Mutations in the RNA splicing factor SF3B1 are common across hematologic and solid cancers and result in widespread alterations in splicing but therapeutic means to correct this mis-splicing do not exist. Here we utilize synthetic introns uniquely responsive to mutant SF3B1 to identify trans factors required for aberrant mutant SF3B1 splicing activity. This revealed the G-patch domain containing protein GPATCH8 as required for mutant SF3B1-induced splicing alterations and impaired hematopoiesis. GPATCH8 is involved in quality control of branchpoint selection, interacts with the RNA helicase DHX15, and functionally opposes SUGP1, a G-patch protein recently implicated in SF3B1 mutant diseases. Silencing of GPATCH8 corrected one-third of mutant SF3B1 splicing defects and was sufficient to improve hematopoiesis in SF3B1 mutant mouse and human cells. These data identify GPATCH8 as a novel splicing factor required for mis-splicing by mutant SF3B1 and the therapeutic impact of correcting aberrant splicing in SF3B1 mutant cancers.
2023-09-01 | GSE242092 | GEO
Project description:Mutations in the RNA splicing factor SF3B1 are common across hematologic and solid cancers and result in widespread alterations in splicing but therapeutic means to correct this mis-splicing do not exist. Here we utilize synthetic introns uniquely responsive to mutant SF3B1 to identify trans factors required for aberrant mutant SF3B1 splicing activity. This revealed the G-patch domain containing protein GPATCH8 as required for mutant SF3B1-induced splicing alterations and impaired hematopoiesis. GPATCH8 is involved in quality control of branchpoint selection, interacts with the RNA helicase DHX15, and functionally opposes SUGP1, a G-patch protein recently implicated in SF3B1 mutant diseases. Silencing of GPATCH8 corrected one-third of mutant SF3B1 splicing defects and was sufficient to improve hematopoiesis in SF3B1 mutant mouse and human cells. These data identify GPATCH8 as a novel splicing factor required for mis-splicing by mutant SF3B1 and the therapeutic impact of correcting aberrant splicing in SF3B1 mutant cancers.
2023-09-01 | GSE242093 | GEO
Project description:Mutations in the RNA splicing factor SF3B1 are common across hematologic and solid cancers and result in widespread alterations in splicing but therapeutic means to correct this mis-splicing do not exist. Here we utilize synthetic introns uniquely responsive to mutant SF3B1 to identify trans factors required for aberrant mutant SF3B1 splicing activity. This revealed the G-patch domain containing protein GPATCH8 as required for mutant SF3B1-induced splicing alterations and impaired hematopoiesis. GPATCH8 is involved in quality control of branchpoint selection, interacts with the RNA helicase DHX15, and functionally opposes SUGP1, a G-patch protein recently implicated in SF3B1 mutant diseases. Silencing of GPATCH8 corrected one-third of mutant SF3B1 splicing defects and was sufficient to improve hematopoiesis in SF3B1 mutant mouse and human cells. These data identify GPATCH8 as a novel splicing factor required for mis-splicing by mutant SF3B1 and the therapeutic impact of correcting aberrant splicing in SF3B1 mutant cancers.
2024-03-20 | GSE262021 | GEO
Project description:UNLABELLED:Uveal melanoma, the most common eye malignancy, causes severe visual morbidity and is fatal in approximately 50% of patients. Primary uveal melanoma can be cured by surgery or radiotherapy, but the metastatic disease is treatment refractory. To understand comprehensively uveal melanoma genetics, we conducted single-nucleotide polymorphism arrays and whole-genome sequencing on 12 primary uveal melanomas. We observed only approximately 2,000 predicted somatic single-nucleotide variants per tumor and low levels of aneuploidy. We did not observe an ultraviolet radiation DNA damage signature, but identified SF3B1 mutations in three samples and a further 15 mutations in an extension cohort of 105 samples. SF3B1 mutations were associated with good prognosis and were rarely coincident with BAP1 mutations. SF3B1 encodes a component of the spliceosome, and RNA sequencing revealed that SF3B1 mutations were associated with differential alternative splicing of protein coding genes, including ABCC5 and UQCC, and of the long noncoding RNA CRNDE. SIGNIFICANCE:Our data show that despite its dismal prognosis, uveal melanoma is a relatively simple genetic disease characterized by recurrent chromosomal losses and gains and a low mutational burden. We show that SF3B1 is recurrently mutated in uveal melanoma, and the mutations are associated with aberrant alternative splicing.
| S-EPMC5321577 | biostudies-literature
Project description:Mutations in the RNA splicing factor gene SF3B1 are common across hematologic and solid cancers and result in widespread alterations in splicing, but therapeutic means to correct this mis-splicing do not exist. Here, we utilize synthetic introns uniquely responsive to mutant SF3B1 to identify trans factors required for aberrant mutant SF3B1 splicing activity. This revealed the G-patch domain-containing protein GPATCH8 as required for mutant SF3B1-induced splicing alterations and impaired hematopoiesis. GPATCH8 is involved in quality control of branchpoint selection, interacts with the RNA helicase DHX15, and functionally opposes SUGP1, a G-patch protein recently implicated in SF3B1-mutant diseases. Silencing of GPATCH8 corrected one-third of mutant SF3B1-dependent splicing defects and was sufficient to improve dysfunctional hematopoiesis in SF3B1-mutant mouse and primary human progenitors. These data identify GPATCH8 as a novel splicing factor required for mis-splicing by mutant SF3B1 and highlight the therapeutic impact of correcting aberrant splicing in SF3B1-mutant cancers.
2024-04-10 | PXD051128 | Pride
Project description:In plant mitochondria, gene expression of translatable mRNAs is a complex process with two critical steps, RNA editing and splicing. We studied the role of RNA editing on non-coding regions of the mat-r-nad1e-nad5c transcript from wheat mitochondria. This RNA contains two trans-introns, 3'-nad1-I4 and 3'-nad5-I2, involved in different trans-splicing events, ensuring the association of nad1d-nad1e and nad5b-nad5c exons from nad1 and nad5 mRNAs respectively. The C-to-U editing changes studied here affect homologous positions on 3'-nad1-I4 and 3'-nad5-I2. It is proposed that these base changes are necessary to place an Adenosine residue in a bulging conformation characteristic of domain VI (D6) from group II introns. In this work, we investigated the role of RNA editing events on 3'-nad1-I4 and 3'-nad5-I2 in the trans-splicing process using in vivo and in organello approaches. When the branched intermediates formed during the splicing process were analyzed, the C residues from D6 intron domains from 3'-nad1-I4 and 3'-nad5-I2 were found changed to U, suggesting that RNA editing of these residues could be mandatory for splicing. This assumption was tested by expressing recombinant mat-r-nad1e transgenes introduced into mitochondria by electroporation. Mutation of the editing target residue dramatically affected trans-splicing. Interestingly, the exon joining efficiency was not recovered by compensatory mutations, suggesting that the role of RNA editing is not confined to the restoration of the secondary structure of domain D6 of the intron. Our results strongly support the hypothesis that RNA editing in trans-introns precedes maturation, and is required for the splicing reaction. In addition, this is the first report using an in organello approach to study the trans-splicing process, opening the way to future studies of this peculiar mechanism.
| S-EPMC3527595 | biostudies-literature
Project description:Previous studies studying mis-splicing mutations were based on exome data and thus our current knowledge is largely limited to exons and the canonical splice sites. To comprehensively characterise intronic mis-splicing mutations, we analysed 1134 pan-cancer whole genomes and transcriptomes together with 3022 normal control samples. The ratio-based splicing analysis resulted in 678 somatic intronic mutations, with 46% residing in deep introns. Among the 309 deep intronic single nucleotide variants, 245 altered core splicing codes, with 38% activating cryptic splice sites, 12% activating cryptic polypyrimidine tracts, and 36% and 12% disrupting authentic polypyrimidine tracts and branchpoints, respectively. All the intronic cryptic splice sites were created at pre-existing GT/AG dinucleotides or by GC-to-GT conversion. Notably, 85 deep intronic mutations indicated gain of splicing enhancers or loss of splicing silencers. We found that 64 tumour suppressors were affected by intronic mutations and blood cancers showed higher proportion of deep intronic mutations. In particular, a telomere maintenance gene, POT1, was recurrently mis-spliced by deep intronic mutations in blood cancers. We validated a pseudoexon activation involving a splicing silencer in POT1 by CRISPR/Cas9. Our results shed light on previously unappreciated mechanisms by which noncoding mutations acting on splicing codes in deep introns contribute to tumourigenesis.
| S-EPMC7892346 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2017-08-22 | GSE97984 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2022-07-09 | GSE185813 | GEO
Project description:Although mutations in the gene encoding the RNA splicing factor SF3B1 are frequent in multiple cancers, their functional effects and therapeutic dependencies are poorly understood. Here, we characterize 98 tumors and 12 isogenic cell lines harboring SF3B1 hotspot mutations, identifying hundreds of cryptic 3' splice sites common and specific to different cancer types. Regulatory network analysis revealed that the most common SF3B1 mutation activates MYC via effects conserved across human and mouse cells. SF3B1 mutations promote decay of transcripts encoding the protein phosphatase 2A (PP2A) subunit PPP2R5A, increasing MYC S62 and BCL2 S70 phosphorylation which, in turn, promotes MYC protein stability and impair apoptosis, respectively. Genetic PPP2R5A restoration or pharmacologic PP2A activation impaired SF3B1-mutant tumorigenesis, elucidating a therapeutic approach to aberrant splicing by mutant SF3B1. SIGNIFICANCE: Here, we identify that mutations in SF3B1, the most commonly mutated splicing factor gene across cancers, alter splicing of a specific subunit of the PP2A serine/threonine phosphatase complex to confer post-translational MYC and BCL2 activation, which is therapeutically intervenable using an FDA-approved drug.See related commentary by O'Connor and Narla, p. 765.This article is highlighted in the In This Issue feature, p. 747.
| S-EPMC8188517 | biostudies-literature