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1.
RNA ; 28(9): 1224-1238, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35768279

RESUMO

The DExD/H-box RNA helicase DHX34 is a nonsense-mediated decay (NMD) factor that together with core NMD factors coregulates NMD targets in nematodes and in vertebrates. Here, we show that DHX34 is also associated with the human spliceosomal catalytic C complex. Mapping of DHX34 endogenous binding sites using cross-linking immunoprecipitation (CLIP) revealed that DHX34 is preferentially associated with pre-mRNAs and locates at exon-intron boundaries. Accordingly, we observed that DHX34 regulates a large number of alternative splicing (AS) events in mammalian cells in culture, establishing a dual role for DHX34 in both NMD and pre-mRNA splicing. We previously showed that germline DHX34 mutations associated to familial myelodysplasia (MDS)/acute myeloid leukemia (AML) predisposition abrogate its activity in NMD. Interestingly, we observe now that DHX34 regulates the splicing of pre-mRNAs that have been linked to AML/MDS predisposition. This is consistent with silencing experiments in hematopoietic stem/progenitor cells (HSPCs) showing that loss of DHX34 results in differentiation blockade of both erythroid and myeloid lineages, which is a hallmark of AML development. Altogether, these data unveil new cellular functions of DHX34 and suggest that alterations in the levels and/or activity of DHX34 could contribute to human disease.


Assuntos
Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Processamento Alternativo , Animais , Humanos , Leucemia Mieloide Aguda/genética , Mamíferos/genética , Síndromes Mielodisplásicas/genética , Degradação do RNAm Mediada por Códon sem Sentido , RNA Helicases/genética , RNA Helicases/metabolismo , Precursores de RNA/genética , Precursores de RNA/metabolismo , Splicing de RNA , RNA Mensageiro/genética
2.
Br J Haematol ; 199(5): 754-764, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36156210

RESUMO

Despite the inclusion of inherited myeloid malignancies as a separate entity in the World Health Organization Classification, many established predisposing loci continue to lack functional characterization. While germline mutations in the DNA repair factor ERCC excision repair 6 like 2 (ERCC6L2) give rise to bone marrow failure and acute myeloid leukaemia, their consequences on normal haematopoiesis remain unclear. To functionally characterise the dual impact of germline ERCC6L2 loss on human primary haematopoietic stem/progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs), we challenged ERCC6L2-silenced and patient-derived cells ex vivo. Here, we show for the first time that ERCC6L2-deficiency in HSPCs significantly impedes their clonogenic potential and leads to delayed erythroid differentiation. This observation was confirmed by CIBERSORTx RNA-sequencing deconvolution performed on ERCC6L2-silenced erythroid-committed cells, which demonstrated higher proportions of polychromatic erythroblasts and reduced orthochromatic erythroblasts versus controls. In parallel, we demonstrate that the consequences of ERCC6L2-deficiency are not limited to HSPCs, as we observe a striking phenotype in patient-derived and ERCC6L2-silenced MSCs, which exhibit enhanced osteogenesis and suppressed adipogenesis. Altogether, our study introduces a valuable surrogate model to study the impact of inherited myeloid mutations and highlights the importance of accounting for the influence of germline mutations in HSPCs and their microenvironment.


Assuntos
Medula Óssea , Eritropoese , Humanos , Eritropoese/genética , Mutação em Linhagem Germinativa , Reparo do DNA/genética , Células Germinativas , DNA Helicases/genética
3.
Br J Haematol ; 188(1): 49-62, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31863468

RESUMO

Modern management of acute myeloid leukaemia (AML) relies on the integration of phenotypic and genetic data to assign classification, establish prognosis, enhance monitoring and guide treatment. The prism through which we can now disperse a patient's leukaemia, interpret and apply our understanding has fundamentally changed since the completion of the first whole-genome sequencing (WGS) of an AML patient in 2008 and where possible, many clinicians would now prefer to delay treatment decisions until the karyotype and genetic status of a new patient is known. The success of global sequencing initiatives such as The Cancer Genome Atlas (TCGA) have brought us significantly closer to cataloguing the full spectrum of coding mutations involved in human malignancy. Indeed, genetic capability has raced ahead of our capacity to apply much of this knowledge into clinical practice and we are in the peculiar position of having routine access to genetic information on an individual patient's leukaemia that cannot be reliably interpreted or utilised. This is a measure of how rapid the progress has been, and this rate of change is likely to continue into the foreseeable future as research intensifies on the non-coding genome and the epigenome, as we scrutinise disease at a single cell level, and as initiatives like Beat AML and the Harmony Alliance progress. In this review, we will examine how interrogation of the coding genome is revolutionising our understanding of AML and improving our ability to underscore differences between paediatric and adult onset, sporadic and inherited forms of disease. We will look at how this knowledge is informing improvements in outcome prediction and the development of novel treatments, bringing us a step closer to personalised therapy for myeloid malignancy.


Assuntos
Bases de Dados Genéticas , Epigenoma , Genoma Humano , Leucemia Mieloide Aguda/genética , Mutação , Sequenciamento Completo do Genoma , Humanos , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/terapia
4.
Nat Commun ; 11(1): 1044, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32098966

RESUMO

The inclusion of familial myeloid malignancies as a separate disease entity in the revised WHO classification has renewed efforts to improve the recognition and management of this group of at risk individuals. Here we report a cohort of 86 acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) families with 49 harboring germline variants in 16 previously defined loci (57%). Whole exome sequencing in a further 37 uncharacterized families (43%) allowed us to rationalize 65 new candidate loci, including genes mutated in rare hematological syndromes (ADA, GP6, IL17RA, PRF1 and SEC23B), reported in prior MDS/AML or inherited bone marrow failure series (DNAH9, NAPRT1 and SH2B3) or variants at novel loci (DHX34) that appear specific to inherited forms of myeloid malignancies. Altogether, our series of MDS/AML families offer novel insights into the etiology of myeloid malignancies and provide a framework to prioritize variants for inclusion into routine diagnostics and patient management.


Assuntos
Mutação em Linhagem Germinativa , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Adenosina Desaminase/genética , Dineínas do Axonema/genética , Estudos de Coortes , Humanos , Degradação do RNAm Mediada por Códon sem Sentido , Linhagem , Perforina/genética , Glicoproteínas da Membrana de Plaquetas/genética , RNA Helicases/genética , Receptores de Interleucina-17/genética , Proteínas de Transporte Vesicular/genética , Sequenciamento do Exoma
6.
Dis Model Mech ; 9(11): 1405-1417, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27660200

RESUMO

Otitis media (OM), or middle ear inflammation, is the most common paediatric disease and leads to significant morbidity. Although understanding of underlying disease mechanisms is hampered by complex pathophysiology it is clear that epithelial abnormalities underpin the disease. There is currently a lack of a well-characterised in vitro model of the middle ear (ME) epithelium that replicates the complex cellular composition of the middle ear. Here, we report the development of a novel in vitro model of mouse middle ear epithelial cells (mMECs) at an air-liquid interface (ALI) that recapitulates the characteristics of the native murine ME epithelium. We demonstrate that mMECs undergo differentiation into the varied cell populations seen within the native middle ear. Proteomic analysis confirmed that the cultures secrete a multitude of innate defence proteins from their apical surface. We showed that the mMECs supported the growth of the otopathogen, nontypeable Haemophilus influenzae (NTHi), suggesting that the model can be successfully utilised to study host-pathogen interactions in the middle ear. Overall, our mMEC culture system can help to better understand the cell biology of the middle ear and improve our understanding of the pathophysiology of OM. The model also has the potential to serve as a platform for validation of treatments designed to reverse aspects of epithelial remodelling that underpin OM development.


Assuntos
Orelha Média/anatomia & histologia , Epitélio/anatomia & histologia , Animais , Biomarcadores/metabolismo , Técnicas de Cultura de Células , Forma Celular , Células Cultivadas , Cílios/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/ultraestrutura , Epitélio/metabolismo , Epitélio/ultraestrutura , Infecções por Haemophilus/microbiologia , Infecções por Haemophilus/patologia , Haemophilus influenzae/fisiologia , Espectrometria de Massas , Camundongos Endogâmicos C57BL , Modelos Animais , Proteoma/metabolismo
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