| 1. |
- Anande, Govardhan, et al.
(författare)
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RNA Splicing Alterations Induce a Cellular Stress Response Associated with Poor Prognosis in Acute Myeloid Leukemia
- 2020
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 26:14, s. 3597-3607
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: RNA splicing is a fundamental biological process that generates protein diversity from a finite set of genes. Recurrent somatic mutations of splicing factor genes are common in some hematologic cancers but are relatively uncommon in acute myeloid leukemia (AML, < 20% of patients). We examined whether RNA splicing differences exist in AML, even in the absence of splicing factor mutations.Experimental Design: We developed a bioinformatics pipeline to study alternative RNA splicing in RNA-sequencing data from large cohorts of patients with AML.Results: We have identified recurrent differential alternative splicing between patients with poor and good prognosis. These splicing events occurred even in patients without any discernible splicing factor mutations. Alternative splicing recurrently occurred in genes with specific molecular functions, primarily related to protein translation. Developing tools to predict the functional impact of alternative splicing on the translated protein, we discovered that approximately 45% of the splicing events directly affected highly conserved protein domains. Several splicing factors were themselves misspliced and the splicing of their target transcripts were altered. Studying differential gene expression in the same patients, we identified that alternative splicing of protein translation genes in ELNAdv patients resulted in the induction of an integrated stress response and upregulation of inflammation-related genes. Finally, using machine learning techniques, we identified a splicing signature of four genes which refine the accuracy of existing risk prognosis schemes and validated it in a completely independent cohort.Conclusions: Our discoveries therefore identify aberrant alternative splicing as a molecular feature of adverse AML with clinical relevance.
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| 2. |
- Hornung, R, et al.
(författare)
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Mediation analysis reveals common mechanisms of RUNX1 point mutations and RUNX1/RUNX1T1 fusions influencing survival of patients with acute myeloid leukemia
- 2018
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8:1, s. 11293-
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Tidskriftsartikel (refereegranskat)abstract
- Alterations of RUNX1 in acute myeloid leukemia (AML) are associated with either a more favorable outcome in the case of the RUNX1/RUNX1T1 fusion or unfavorable prognosis in the case of point mutations. In this project we aimed to identify genes responsible for the observed differences in outcome that are common to both RUNX1 alterations. Analyzing four AML gene expression data sets (n = 1514), a total of 80 patients with RUNX1/RUNX1T1 and 156 patients with point mutations in RUNX1 were compared. Using the statistical tool of mediation analysis we identified the genes CD109, HOPX, and KIAA0125 as candidates for mediator genes. In an analysis of an independent validation cohort, KIAA0125 again showed a significant influence with respect to the impact of the RUNX1/RUNX1T1 fusion. While there were no significant results for the other two genes in this smaller validation cohort, the observed relations linked with mediation effects (i.e., those between alterations, gene expression and survival) were almost without exception as strong as in the main analysis. Our analysis demonstrates that mediation analysis is a powerful tool in the identification of regulative networks in AML subgroups and could be further used to characterize the influence of genetic alterations.
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| 3. |
- Jardin, Fabrice, et al.
(författare)
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Recurrent mutations of the exportin 1 gene (XPO1) and their impact on selective inhibitor of nuclear export compounds sensitivity in primary mediastinal B-cell lymphoma.
- 2016
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Ingår i: American Journal of Hematology. - : Wiley. - 0361-8609 .- 1096-8652. ; 91:9, s. 923-30
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Tidskriftsartikel (refereegranskat)abstract
- Primary mediastinal B-cell lymphoma (PMBL) is an entity of B-cell lymphoma distinct from the other molecular subtypes of diffuse large B-cell lymphoma (DLBCL). We investigated the prevalence, specificity, and clinical relevance of mutations of XPO1, which encodes a member of the karyopherin-β nuclear transporters, in a large cohort of PMBL. PMBL cases defined histologically or by gene expression profiling (GEP) were sequenced and the XPO1 mutational status was correlated to genetic and clinical characteristics. The XPO1 mutational status was also assessed in DLBCL, Hodgkin lymphoma (HL) and mediastinal gray-zone lymphoma (MGZL).The biological impact of the mutation on Selective Inhibitor of Nuclear Export (SINE) compounds (KPT-185/330) sensitivity was investigated in vitro. XPO1 mutations were present in 28/117 (24%) PMBL cases and in 5/19 (26%) HL cases but absent/rare in MGZL (0/20) or DLBCL (3/197). A higher prevalence (50%) of the recurrent codon 571 variant (p.E571K) was observed in GEP-defined PMBL and was associated with shorter PFS. Age, International Prognostic Index and bulky mass were similar in XPO1 mutant and wild-type cases. KPT-185 induced a dose-dependent decrease in cell proliferation and increased cell-death in PMBL cell lines harboring wild type or XPO1 E571K mutant alleles. Experiments in transfected U2OS cells further confirmed that the XPO1 E571K mutation does not have a drastic impact on KPT-330 binding. To conclude the XPO1 E571K mutation represents a genetic hallmark of the PMBL subtype and serves as a new relevant PMBL biomarker. SINE compounds appear active for both mutated and wild-type protein. Am. J. Hematol. 91:923-930, 2016. © 2016 Wiley Periodicals, Inc.
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| 4. |
- Mareschal, Sylvain, et al.
(författare)
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Challenging conventional karyotyping by next-generation karyotyping in 281 intensively treated patients with AML
- 2021
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Ingår i: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 5:4, s. 1003-1016
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Tidskriftsartikel (refereegranskat)abstract
- Although copy number alterations (CNAs) and translocations constitute the backbone of the diagnosis and prognostication of acute myeloid leukemia (AML), techniques used for their assessment in routine diagnostics have not been reconsidered for decades. We used a combination of 2 next-generation sequencing-based techniques to challenge the currently recommended conventional cytogenetic analysis (CCA), comparing the approaches in a series of 281 intensively treated patients with AML. Shallow whole-genome sequencing (sWGS) outperformed CCA in detecting European Leukemia Net (ELN)-defining CNAs and showed that CCA overestimated monosomies and suboptimally reported karyotype complexity. Still, the concordance between CCA and sWGS for all ELN CNA-related criteria was 94%. Moreover, using in silico dilution, we showed that 1 million reads per patient would be enough to accurately assess ELN-defining CNAs. Total genomic loss, defined as a total loss 200 Mb by sWGS, was found to be a better marker for genetic complexity and poor prognosis compared with the CCA-based definition of complex karyotype. For fusion detection, the concordance between CCA and whole-transcriptome sequencing (WTS) was 99%. WTS had better sensitivity in identifying inv(16) and KMT2A rearrangements while showing limitations in detecting lowly expressed PML-RARA fusions. Ligation-dependent reverse transcription polymerase chain reaction was used for validation and was shown to be a fast and reliable method for fusion detection. We conclude that a next-generation sequencing-based approach can replace conventional CCA for karyotyping, provided that efforts are made to cover lowly expressed fusion transcripts.
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| 5. |
- Neddermeyer, Anne, et al.
(författare)
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A new mutant NPM1/IDH2R140- and PML-RARA-associated lncRNA MALNC plays a role in AML biology, prognosis and drug response
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Acute myeloid leukemia (AML) is a hematopoietic malignancy characterized by poor prognosis that requires better understanding of its disease biology and new tools for suitable risk stratification and effective treatments. Long non-coding RNAs (lncRNAs) are involved in numerous molecular mechanisms, are implicated in tumor biology and can serve as clinical biomarkers, yet their role remains mostly unclear in AML. In this study, the aim was to discover and characterize lncRNAs implicated in AML and to describe their role in AML biology. Further aims were to explore their use as prognostic or predictive biomarkers. Using whole-transcriptome analysis, a novel lncRNA, here named MALNC, was identified. MALNC had elevated expression in two large AML cohorts compared to normal CD34+ cells. Clinical correlation analyses indicated that MALNC was almost uniquely expressed in patients with PML-RARA fusion gene and with co-mutated isocitrate dehydrogenase-2 R140 and nucleophosmin-1 (IDH2R140/NPM1). MALNC expression was specifically high at the promyelocytic stage and decreased with maturation in leukemic and normal cells. High MALNC expression associated independently with better overall survival. CRISPR-Cas9-knockout in promyelocytic cell lines impaired proliferation, colony formation and all-trans retinoic acid (ATRA)-induced differentiation. Also, MALNC-knockout dramatically sensitized cells to arsenic trioxide (ATO), ATO-ATRA combinatorial and Bcl-2-inhibitor venetoclax treatment as well as associated with cyclin-dependent kinase (Cdk)-inhibitor resistance. In conclusion, MALNC is overexpressed in certain subgroups of AML and could play a role during normal and leukemic hematopoietic maturation. Furthermore, it correlates with response to anti-leukemic drugs, which suggests a role as a predictive marker to drug response and survival in AML.
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| 6. |
- Österroos, Albin, et al.
(författare)
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Integrated transcriptomic and genomic analysis improves prediction of complete remission and survival in elderly patients with acute myeloid leukemia
- 2020
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Ingår i: Blood Cancer Journal. - : NATURE PUBLISHING GROUP. - 2044-5385. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Relevant molecular tools for treatment stratification of patients >= 65 years with acute myeloid leukemia (AML) are lacking. We combined clinical data with targeted DNA- and full RNA-sequencing of 182 intensively and palliatively treated patients to predict complete remission (CR) and survival in AML patients >= 65 years. Intensively treated patients withNPM1andIDH2(R172)mutations had longer overall survival (OS), whereas mutatedTP53conferred lower CR rates and shorter OS.FLT3-ITDandTP53mutations predicted worse OS in palliatively treated patients. Gene expression levels most predictive of CR were combined with somatic mutations for an integrated risk stratification that we externally validated using the beatAML cohort. We defined a high-risk group with a CR rate of 20% in patients with mutatedTP53, compared to 97% CR in low-risk patients defined by high expression ofZBTB7AandEEPD1withoutTP53mutations. Patients without these criteria had a CR rate of 54% (intermediate risk). The difference in CR rates translated into significant OS differences that outperformed ELN stratification for OS prediction. The results suggest that an integrated molecular risk stratification can improve prediction of CR and OS and could be used to guide treatment in elderly AML patients.
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