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1.
Mol Cell ; 82(13): 2458-2471.e9, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35550257

RESUMO

Many cancers are characterized by gene fusions encoding oncogenic chimeric transcription factors (TFs) such as EWS::FLI1 in Ewing sarcoma (EwS). Here, we find that EWS::FLI1 induces the robust expression of a specific set of novel spliced and polyadenylated transcripts within otherwise transcriptionally silent regions of the genome. These neogenes (NGs) are virtually undetectable in large collections of normal tissues or non-EwS tumors and can be silenced by CRISPR interference at regulatory EWS::FLI1-bound microsatellites. Ribosome profiling and proteomics further show that some NGs are translated into highly EwS-specific peptides. More generally, we show that hundreds of NGs can be detected in diverse cancers characterized by chimeric TFs. Altogether, this study identifies the transcription, processing, and translation of novel, specific, highly expressed multi-exonic transcripts from otherwise silent regions of the genome as a new activity of aberrant TFs in cancer.


Assuntos
Carcinogênese , Regulação Neoplásica da Expressão Gênica , Proteínas de Fusão Oncogênica , Proteína Proto-Oncogênica c-fli-1 , Fatores de Transcrição , Carcinogênese/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Inativação Gênica , Genoma/genética , Genômica , Humanos , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Oncogenes/genética , Proteína Proto-Oncogênica c-fli-1/genética , Proteína Proto-Oncogênica c-fli-1/metabolismo , Sarcoma de Ewing/genética , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/patologia , Fatores de Transcrição/genética , Transcrição Gênica/genética
2.
Am J Hum Genet ; 110(3): 427-441, 2023 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-36787739

RESUMO

Ewing sarcoma (EwS) is a rare bone and soft tissue malignancy driven by chromosomal translocations encoding chimeric transcription factors, such as EWSR1-FLI1, that bind GGAA motifs forming novel enhancers that alter nearby expression. We propose that germline microsatellite variation at the 6p25.1 EwS susceptibility locus could impact downstream gene expression and EwS biology. We performed targeted long-read sequencing of EwS blood DNA to characterize variation and genomic features important for EWSR1-FLI1 binding. We identified 50 microsatellite alleles at 6p25.1 and observed that EwS-affected individuals had longer alleles (>135 bp) with more GGAA repeats. The 6p25.1 GGAA microsatellite showed chromatin features of an EWSR1-FLI1 enhancer and regulated expression of RREB1, a transcription factor associated with RAS/MAPK signaling. RREB1 knockdown reduced proliferation and clonogenic potential and reduced expression of cell cycle and DNA replication genes. Our integrative analysis at 6p25.1 details increased binding of longer GGAA microsatellite alleles with acquired EWSR-FLI1 to promote Ewing sarcomagenesis by RREB1-mediated proliferation.


Assuntos
Neoplasias Ósseas , Sarcoma de Ewing , Humanos , Alelos , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Proteína Proto-Oncogênica c-fli-1/genética , Proteína Proto-Oncogênica c-fli-1/metabolismo , Proteína EWS de Ligação a RNA/genética , Proteína EWS de Ligação a RNA/metabolismo , Sarcoma de Ewing/genética , Sarcoma de Ewing/metabolismo , Sarcoma de Ewing/patologia
3.
Nucleic Acids Res ; 49(9): 5038-5056, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-34009296

RESUMO

ERG family proteins (ERG, FLI1 and FEV) are a subfamily of ETS transcription factors with key roles in physiology and development. In Ewing sarcoma, the oncogenic fusion protein EWS-FLI1 regulates both transcription and alternative splicing of pre-messenger RNAs. However, whether wild-type ERG family proteins might regulate splicing is unknown. Here, we show that wild-type ERG proteins associate with spliceosomal components, are found on nascent RNAs, and induce alternative splicing when recruited onto a reporter minigene. Transcriptomic analysis revealed that ERG and FLI1 regulate large numbers of alternative spliced exons (ASEs) enriched with RBFOX2 motifs and co-regulated by this splicing factor. ERG and FLI1 are associated with RBFOX2 via their conserved carboxy-terminal domain, which is present in EWS-FLI1. Accordingly, EWS-FLI1 is also associated with RBFOX2 and regulates ASEs enriched in RBFOX2 motifs. However, in contrast to wild-type ERG and FLI1, EWS-FLI1 often antagonizes RBFOX2 effects on exon inclusion. In particular, EWS-FLI1 reduces RBFOX2 binding to the ADD3 pre-mRNA, thus increasing its long isoform, which represses the mesenchymal phenotype of Ewing sarcoma cells. Our findings reveal a RBFOX2-mediated splicing regulatory function of wild-type ERG family proteins, that is altered in EWS-FLI1 and contributes to the Ewing sarcoma cell phenotype.


Assuntos
Processamento Alternativo , Proteínas de Fusão Oncogênica/metabolismo , Proteína Proto-Oncogênica c-fli-1/metabolismo , Fatores de Processamento de RNA/metabolismo , Proteína EWS de Ligação a RNA/metabolismo , Proteínas Repressoras/metabolismo , Proteínas de Ligação a Calmodulina/genética , Proteínas de Ligação a Calmodulina/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Células HeLa , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Domínios Proteicos , Sarcoma de Ewing/genética , Sarcoma de Ewing/metabolismo , Regulador Transcricional ERG/química , Regulador Transcricional ERG/metabolismo
4.
Haematologica ; 107(1): 268-283, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33241676

RESUMO

The gene CXXC5, encoding a Retinoid-Inducible Nuclear Factor (RINF), is located within a region at 5q31.2 commonly deleted in myelodysplastic syndrome (MDS) and adult acute myeloid leukemia (AML). RINF may act as an epigenetic regulator and has been proposed as a tumor suppressor in hematopoietic malignancies. However, functional studies in normal hematopoiesis are lacking, and its mechanism of action is unknow. Here, we evaluated the consequences of RINF silencing on cytokineinduced erythroid differentiation of human primary CD34+ progenitors. We found that RINF is expressed in immature erythroid cells and that RINF-knockdown accelerated erythropoietin-driven maturation, leading to a significant reduction (~45%) in the number of red blood cells (RBCs), without affecting cell viability. The phenotype induced by RINF-silencing was TGFß-dependent and mediated by SMAD7, a TGFß- signaling inhibitor. RINF upregulates SMAD7 expression by direct binding to its promoter and we found a close correlation between RINF and SMAD7 mRNA levels both in CD34+ cells isolated from bone marrow of healthy donors and MDS patients with del(5q). Importantly, RINF knockdown attenuated SMAD7 expression in primary cells and ectopic SMAD7 expression was sufficient to prevent the RINF knockdowndependent erythroid phenotype. Finally, RINF silencing affects 5'-hydroxymethylation of human erythroblasts, in agreement with its recently described role as a Tet2- anchoring platform in mouse. Altogether, our data bring insight into how the epigenetic factor RINF, as a transcriptional regulator of SMAD7, may fine-tune cell sensitivity to TGFß superfamily cytokines and thus play an important role in both normal and pathological erythropoiesis.


Assuntos
Proteínas de Ligação a DNA , Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Proteína Smad7 , Fatores de Transcrição , Adulto , Animais , Ciclo Celular , Epigênese Genética , Humanos , Leucemia Mieloide Aguda/genética , Camundongos , Síndromes Mielodisplásicas/genética , RNA Mensageiro , Proteína Smad7/genética
5.
Brain ; 138(Pt 1): 53-68, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25384799

RESUMO

Amyotrophic lateral sclerosis is the most common adult-onset motor neuron disease and evidence from mice expressing amyotrophic lateral sclerosis-causing SOD1 mutations suggest that neurodegeneration is a non-cell autonomous process where microglial cells influence disease progression. However, microglial-derived neurotoxic factors still remain largely unidentified in amyotrophic lateral sclerosis. With excitotoxicity being a major mechanism proposed to cause motor neuron death in amyotrophic lateral sclerosis, our hypothesis was that excessive glutamate release by activated microglia through their system [Formula: see text] (a cystine/glutamate antiporter with the specific subunit xCT/Slc7a11) could contribute to neurodegeneration. Here we show that xCT expression is enriched in microglia compared to total mouse spinal cord and absent from motor neurons. Activated microglia induced xCT expression and during disease, xCT levels were increased in both spinal cord and isolated microglia from mutant SOD1 amyotrophic lateral sclerosis mice. Expression of xCT was also detectable in spinal cord post-mortem tissues of patients with amyotrophic lateral sclerosis and correlated with increased inflammation. Genetic deletion of xCT in mice demonstrated that activated microglia released glutamate mainly through system [Formula: see text]. Interestingly, xCT deletion also led to decreased production of specific microglial pro-inflammatory/neurotoxic factors including nitric oxide, TNFa and IL6, whereas expression of anti-inflammatory/neuroprotective markers such as Ym1/Chil3 were increased, indicating that xCT regulates microglial functions. In amyotrophic lateral sclerosis mice, xCT deletion surprisingly led to earlier symptom onset but, importantly, this was followed by a significantly slowed progressive disease phase, which resulted in more surviving motor neurons. These results are consistent with a deleterious contribution of microglial-derived glutamate during symptomatic disease. Therefore, we show that system [Formula: see text] participates in microglial reactivity and modulates amyotrophic lateral sclerosis motor neuron degeneration, revealing system [Formula: see text] inactivation, as a potential approach to slow amyotrophic lateral sclerosis disease progression after onset of clinical symptoms.


Assuntos
Sistema ASC de Transporte de Aminoácidos/deficiência , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/fisiopatologia , Microglia/metabolismo , Esclerose Lateral Amiotrófica/mortalidade , Animais , Animais Recém-Nascidos , Córtex Cerebral/citologia , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Glutationa/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/metabolismo , Mutação/genética , Óxido Nítrico/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase-1
6.
Nat Commun ; 14(1): 8361, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38102136

RESUMO

Activation of oncogenic gene expression from long-range enhancers is initiated by the assembly of DNA-binding transcription factors (TF), leading to recruitment of co-activators such as CBP/p300 to modify the local genomic context and facilitate RNA-Polymerase 2 (Pol2) binding. Yet, most TF-to-coactivator recruitment relationships remain unmapped. Here, studying the oncogenic fusion TF PAX3-FOXO1 (P3F) from alveolar rhabdomyosarcoma (aRMS), we show that a single cysteine in the activation domain (AD) of P3F is important for a small alpha helical coil that recruits CBP/p300 to chromatin. P3F driven transcription requires both this single cysteine and CBP/p300. Mutants of the cysteine reduce aRMS cell proliferation and induce cellular differentiation. Furthermore, we discover a profound dependence on CBP/p300 for clustering of Pol2 loops that connect P3F to its target genes. In the absence of CBP/p300, Pol2 long range enhancer loops collapse, Pol2 accumulates in CpG islands and fails to exit the gene body. These results reveal a potential novel axis for therapeutic interference with P3F in aRMS and clarify the molecular relationship of P3F and CBP/p300 in sustaining active Pol2 clusters essential for oncogenic transcription.


Assuntos
RNA Polimerase II , Rabdomiossarcoma Alveolar , Humanos , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Cisteína/metabolismo , Fatores de Transcrição/metabolismo , Fator de Transcrição PAX3/genética , Rabdomiossarcoma Alveolar/genética , RNA/metabolismo , Ativação Transcricional , Ligação Proteica , Proteína Forkhead Box O1/metabolismo
7.
Nat Commun ; 14(1): 3034, 2023 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-37236926

RESUMO

Renal medullary carcinoma (RMC) is an aggressive tumour driven by bi-allelic loss of SMARCB1 and tightly associated with sickle cell trait. However, the cell-of-origin and oncogenic mechanism remain poorly understood. Using single-cell sequencing of human RMC, we defined transformation of thick ascending limb (TAL) cells into an epithelial-mesenchymal gradient of RMC cells associated with loss of renal epithelial transcription factors TFCP2L1, HOXB9 and MITF and gain of MYC and NFE2L2-associated oncogenic and ferroptosis resistance programs. We describe the molecular basis for this transcriptional switch that is reversed by SMARCB1 re-expression repressing the oncogenic and ferroptosis resistance programs leading to ferroptotic cell death. Ferroptosis resistance links TAL cell survival with the high extracellular medullar iron concentrations associated with sickle cell trait, an environment propitious to the mutagenic events associated with RMC development. This unique environment may explain why RMC is the only SMARCB1-deficient tumour arising from epithelial cells, differentiating RMC from rhabdoid tumours arising from neural crest cells.


Assuntos
Carcinoma Medular , Carcinoma de Células Renais , Ferroptose , Neoplasias Renais , Traço Falciforme , Humanos , Neoplasias Renais/patologia , Carcinoma Medular/metabolismo , Carcinoma de Células Renais/patologia , Proteína SMARCB1/genética , Proteína SMARCB1/metabolismo , Proteínas Repressoras , Proteínas de Homeodomínio
8.
Commun Biol ; 6(1): 949, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37723198

RESUMO

Pediatric patients with recurrent and refractory cancers are in most need for new treatments. This study developed patient-derived-xenograft (PDX) models within the European MAPPYACTS cancer precision medicine trial (NCT02613962). To date, 131 PDX models were established following heterotopical and/or orthotopical implantation in immunocompromised mice: 76 sarcomas, 25 other solid tumors, 12 central nervous system tumors, 15 acute leukemias, and 3 lymphomas. PDX establishment rate was 43%. Histology, whole exome and RNA sequencing revealed a high concordance with the primary patient's tumor profile, human leukocyte-antigen characteristics and specific metabolic pathway signatures. A detailed patient molecular characterization, including specific mutations prioritized in the clinical molecular tumor boards are provided. Ninety models were shared with the IMI2 ITCC Pediatric Preclinical Proof-of-concept Platform (IMI2 ITCC-P4) for further exploitation. This PDX biobank of unique recurrent childhood cancers provides an essential support for basic and translational research and treatments development in advanced pediatric malignancies.


Assuntos
Leucemia , Neoplasias , Animais , Criança , Humanos , Camundongos , Bancos de Espécimes Biológicos , Modelos Animais de Doenças , Xenoenxertos , Neoplasias/genética , Medicina de Precisão , Ensaios Clínicos como Assunto
9.
Nat Commun ; 14(1): 2575, 2023 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-37142597

RESUMO

Noradrenergic and mesenchymal identities have been characterized in neuroblastoma cell lines according to their epigenetic landscapes and core regulatory circuitries. However, their relationship and relative contribution in patient tumors remain poorly defined. We now document spontaneous and reversible plasticity between the two identities, associated with epigenetic reprogramming, in several neuroblastoma models. Interestingly, xenografts with cells from each identity eventually harbor a noradrenergic phenotype suggesting that the microenvironment provides a powerful pressure towards this phenotype. Accordingly, such a noradrenergic cell identity is systematically observed in single-cell RNA-seq of 18 tumor biopsies and 15 PDX models. Yet, a subpopulation of these noradrenergic tumor cells presents with mesenchymal features that are shared with plasticity models, indicating that the plasticity described in these models has relevance in neuroblastoma patients. This work therefore emphasizes that intrinsic plasticity properties of neuroblastoma cells are dependent upon external cues of the environment to drive cell identity.


Assuntos
Plasticidade Celular , Neuroblastoma , Humanos , Neuroblastoma/metabolismo , Linhagem Celular Tumoral , Microambiente Tumoral/genética
10.
Cancers (Basel) ; 14(9)2022 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-35565457

RESUMO

Ewing sarcoma (EwS) is an aggressive primary bone cancer in children and young adults characterized by oncogenic fusions between genes encoding FET-RNA-binding proteins and ETS transcription factors, the most frequent fusion being EWSR1-FLI1. We show that EGR2, an Ewing-susceptibility gene and an essential direct target of EWSR1-FLI1, directly regulates the transcription of genes encoding key enzymes of the mevalonate (MVA) pathway. Consequently, Ewing sarcoma is one of the tumors that expresses the highest levels of mevalonate pathway genes. Moreover, genome-wide screens indicate that MVA pathway genes constitute major dependencies of Ewing cells. Accordingly, the statin inhibitors of HMG-CoA-reductase, a rate-limiting enzyme of the MVA pathway, demonstrate cytotoxicity in EwS. Statins induce increased ROS and lipid peroxidation levels, as well as decreased membrane localization of prenylated proteins, such as small GTP proteins. These metabolic effects lead to an alteration in the dynamics of S-phase progression and to apoptosis. Statin-induced effects can be rescued by downstream products of the MVA pathway. Finally, we further show that statins impair tumor growth in different Ewing PDX models. Altogether, the data show that statins, which are off-patent, well-tolerated, and inexpensive compounds, should be strongly considered in the therapeutic arsenal against this deadly childhood disease.

11.
Cell Rep ; 41(10): 111761, 2022 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-36476851

RESUMO

Ewing sarcoma (EwS) is characterized by EWSR1-ETS fusion transcription factors converting polymorphic GGAA microsatellites (mSats) into potent neo-enhancers. Although the paucity of additional mutations makes EwS a genuine model to study principles of cooperation between dominant fusion oncogenes and neo-enhancers, this is impeded by the limited number of well-characterized models. Here we present the Ewing Sarcoma Cell Line Atlas (ESCLA), comprising whole-genome, DNA methylation, transcriptome, proteome, and chromatin immunoprecipitation sequencing (ChIP-seq) data of 18 cell lines with inducible EWSR1-ETS knockdown. The ESCLA shows hundreds of EWSR1-ETS-targets, the nature of EWSR1-ETS-preferred GGAA mSats, and putative indirect modes of EWSR1-ETS-mediated gene regulation, converging in the duality of a specific but plastic EwS signature. We identify heterogeneously regulated EWSR1-ETS-targets as potential prognostic EwS biomarkers. Our freely available ESCLA (http://r2platform.com/escla/) is a rich resource for EwS research and highlights the power of comprehensive datasets to unravel principles of heterogeneous gene regulation by chimeric transcription factors.


Assuntos
Sarcoma de Ewing , Humanos , Sarcoma de Ewing/genética , Multiômica , Oncogenes , Linhagem Celular , Fatores de Transcrição
12.
JCO Precis Oncol ; 6: e2100534, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36265118

RESUMO

PURPOSE: Rhabdomyosarcomas (RMS) are rare neoplasms affecting children and young adults. Efforts to improve patient survival have been undermined by a lack of suitable disease markers. Plasma circulating tumor DNA (ctDNA) has shown promise as a potential minimally invasive biomarker and monitoring tool in other cancers; however, it remains underexplored in RMS. We aimed to determine the feasibility of identifying and quantifying ctDNA in plasma as a marker of disease burden and/or treatment response using blood samples from RMS mouse models and patients. METHODS: We established mouse models of RMS and applied quantitative polymerase chain reaction (PCR) and droplet digital PCR (ddPCR) to detect ctDNA within the mouse plasma. Potential driver mutations, copy-number alterations, and DNA breakpoints associated with PAX3/7-FOXO1 gene fusions were identified in the RMS samples collected at diagnosis. Patient-matched plasma samples collected from 28 patients with RMS before, during, and after treatment were analyzed for the presence of ctDNA via ddPCR, panel sequencing, and/or whole-exome sequencing. RESULTS: Human tumor-derived DNA was detectable in plasma samples from mouse models of RMS and correlated with tumor burden. In patients, ctDNA was detected in 14/18 pretreatment plasma samples with ddPCR and 7/7 cases assessed by sequencing. Levels of ctDNA at diagnosis were significantly higher in patients with unfavorable tumor sites, positive nodal status, and metastasis. In patients with serial plasma samples (n = 18), fluctuations in ctDNA levels corresponded to treatment response. CONCLUSION: Comprehensive ctDNA analysis combining high sensitivity and throughput can identify key molecular drivers in RMS models and patients, suggesting potential as a minimally invasive biomarker. Preclinical assessment of treatments using mouse models and further patient testing through prospective clinical trials are now warranted.


Assuntos
DNA Tumoral Circulante , Neoplasias , Rabdomiossarcoma Embrionário , Humanos , Criança , Camundongos , Animais , DNA Tumoral Circulante/genética , Estudos de Viabilidade , Estudos Prospectivos , Biomarcadores Tumorais/genética , Mutação
13.
Gastroenterology ; 139(4): 1355-64, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20600021

RESUMO

BACKGROUND & AIMS: Although hepatitis C virus (HCV) can be grown in the hepatocarcinoma-derived cell line Huh-7, a cell-culture model is needed that supports its complete, productive infection cycle in normal, quiescent, highly differentiated human hepatocytes. We sought to develop such a system. METHODS: Primary cultures of human adult hepatocytes were inoculated with HCV derived from Huh-7 cell culture (HCVcc) and monitored for expression of hepatocyte differentiation markers and replication of HCV. Culture supernatants were assayed for HCV RNA, core antigen, and infectivity titer. The buoyant densities of input and progeny virus were compared in iodixanol gradients. RESULTS: While retaining expression of differentiation markers, primary hepatocytes supported the complete infectious cycle of HCV, including production of significant titers of new infectious progeny virus, which was called primary-culture-derived virus (HCVpc). Compared with HCVcc, HCVpc had lower average buoyant density and higher specific infectivity; this was similar to the characteristics of virus particles associated with the very-low-density lipoproteins that are produced during in vivo infection. These properties were lost after re-culture of HCVpc in poorly differentiated Huh-7 cells, suggesting that authentic virions can be produced only by normal hepatocytes that secrete authentic very-low-density lipoproteins. CONCLUSIONS: We have established a cell-culture-based system that allows production of infectious HCV in physiologically relevant human hepatocytes. This provides a useful tool for the study of HCV interactions with its natural host cell and for the development of antiviral therapies.


Assuntos
Hepacivirus/fisiologia , Hepatócitos/virologia , Replicação Viral , Adulto , Diferenciação Celular , Linhagem Celular Tumoral , Genoma Viral , Humanos
14.
Cancer Cell ; 39(6): 810-826.e9, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-33930311

RESUMO

STAG2, a cohesin family gene, is among the most recurrently mutated genes in cancer. STAG2 loss of function (LOF) is associated with aggressive behavior in Ewing sarcoma, a childhood cancer driven by aberrant transcription induced by the EWSR1-FLI1 fusion oncogene. Here, using isogenic Ewing cells, we show that, while STAG2 LOF profoundly changes the transcriptome, it does not significantly impact EWSR1-FLI1, CTCF/cohesin, or acetylated H3K27 DNA binding patterns. In contrast, it strongly alters the anchored dynamic loop extrusion process at boundary CTCF sites and dramatically decreases promoter-enhancer interactions, particularly affecting the expression of genes regulated by EWSR1-FLI1 at GGAA microsatellite neo-enhancers. Down-modulation of cis-mediated EWSR1-FLI1 activity, observed in STAG2-LOF conditions, is associated with enhanced migration and invasion properties of Ewing cells previously observed in EWSR1-FLI1low cells. Our study illuminates a process whereby STAG2-LOF fine-tunes the activity of an oncogenic transcription factor through altered CTCF-anchored loop extrusion and cis-mediated enhancer mechanisms.


Assuntos
Neoplasias Ósseas/genética , Fator de Ligação a CCCTC/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Fusão Oncogênica/genética , Sarcoma de Ewing/genética , Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/patologia , Fator de Ligação a CCCTC/química , Fator de Ligação a CCCTC/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Imunoprecipitação da Cromatina , Proteínas Cromossômicas não Histona/metabolismo , Elementos Facilitadores Genéticos , Regulação Neoplásica da Expressão Gênica , Histonas/metabolismo , Humanos , Mutação com Perda de Função , Lisina/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Regiões Promotoras Genéticas , Sarcoma de Ewing/mortalidade , Sarcoma de Ewing/patologia , Coesinas
15.
Cancer Res ; 81(19): 4994-5006, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34341072

RESUMO

Ewing sarcoma is characterized by pathognomonic translocations, most frequently fusing EWSR1 with FLI1. An estimated 30% of Ewing sarcoma tumors also display genetic alterations in STAG2, TP53, or CDKN2A (SPC). Numerous attempts to develop relevant Ewing sarcoma models from primary human cells have been unsuccessful in faithfully recapitulating the phenotypic, transcriptomic, and epigenetic features of Ewing sarcoma. In this study, by engineering the t(11;22)(q24;q12) translocation together with a combination of SPC mutations, we generated a wide collection of immortalized cells (EWIma cells) tolerating EWSR1-FLI1 expression from primary mesenchymal stem cells (MSC) derived from a patient with Ewing sarcoma. Within this model, SPC alterations strongly favored Ewing sarcoma oncogenicity. Xenograft experiments with independent EWIma cells induced tumors and metastases in mice, which displayed bona fide features of Ewing sarcoma. EWIma cells presented balanced but also more complex translocation profiles mimicking chromoplexy, which is frequently observed in Ewing sarcoma and other cancers. Collectively, these results demonstrate that bone marrow-derived MSCs are a source of origin for Ewing sarcoma and also provide original experimental models to investigate Ewing sarcomagenesis. SIGNIFICANCE: These findings demonstrate that Ewing sarcoma can originate from human bone-marrow-derived mesenchymal stem cells and that recurrent mutations support EWSR1-FLI1 translocation-mediated transformation.


Assuntos
Transformação Celular Neoplásica , Suscetibilidade a Doenças , Células-Tronco Mesenquimais/metabolismo , Sarcoma de Ewing/etiologia , Sarcoma de Ewing/metabolismo , Animais , Biomarcadores , Sistemas CRISPR-Cas , Células Cultivadas , Biologia Computacional/métodos , Modelos Animais de Doenças , Edição de Genes , Perfilação da Expressão Gênica , Rearranjo Gênico , Marcação de Genes , Xenoenxertos , Humanos , Imunofenotipagem , Hibridização in Situ Fluorescente , Células-Tronco Mesenquimais/patologia , Camundongos , Mutação , Sarcoma de Ewing/patologia , Translocação Genética
16.
Nat Neurosci ; 23(11): 1339-1351, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33077946

RESUMO

Microglia and peripheral macrophages have both been implicated in amyotrophic lateral sclerosis (ALS), although their respective roles have yet to be determined. We now show that macrophages along peripheral motor neuron axons in mouse models and patients with ALS react to neurodegeneration. In ALS mice, peripheral myeloid cell infiltration into the spinal cord was limited and depended on disease duration. Targeted gene modulation of the reactive oxygen species pathway in peripheral myeloid cells of ALS mice, using cell replacement, reduced both peripheral macrophage and microglial activation, delayed symptoms and increased survival. Transcriptomics revealed that sciatic nerve macrophages and microglia reacted differently to neurodegeneration, with abrupt temporal changes in macrophages and progressive, unidirectional activation in microglia. Modifying peripheral macrophages suppressed proinflammatory microglial responses, with a shift toward neuronal support. Thus, modifying macrophages at the periphery has the capacity to influence disease progression and may be of therapeutic value for ALS.


Assuntos
Esclerose Lateral Amiotrófica/imunologia , Axônios/imunologia , Macrófagos/imunologia , Microglia/imunologia , Neurônios Motores/imunologia , Nervo Isquiático/imunologia , Adulto , Idoso , Esclerose Lateral Amiotrófica/metabolismo , Animais , Feminino , Humanos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/metabolismo , Pessoa de Meia-Idade , Neurônios Motores/metabolismo , Nervo Isquiático/metabolismo , Medula Espinal/imunologia , Medula Espinal/metabolismo
17.
Cell Rep ; 30(6): 1767-1779.e6, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-32049009

RESUMO

EWSR1-FLI1, the chimeric oncogene specific for Ewing sarcoma (EwS), induces a cascade of signaling events leading to cell transformation. However, it remains elusive how genetically homogeneous EwS cells can drive the heterogeneity of transcriptional programs. Here, we combine independent component analysis of single-cell RNA sequencing data from diverse cell types and model systems with time-resolved mapping of EWSR1-FLI1 binding sites and of open chromatin regions to characterize dynamic cellular processes associated with EWSR1-FLI1 activity. We thus define an exquisitely specific and direct enhancer-driven EWSR1-FLI1 program. In EwS tumors, cell proliferation and strong oxidative phosphorylation metabolism are associated with a well-defined range of EWSR1-FLI1 activity. In contrast, a subpopulation of cells from below and above the intermediary EWSR1-FLI1 activity is characterized by increased hypoxia. Overall, our study reveals sources of intratumoral heterogeneity within EwS tumors.


Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Proteína EWS de Ligação a RNA/metabolismo , Sarcoma de Ewing/genética , Transcrição Gênica/genética , Linhagem Celular Tumoral , Humanos , Transdução de Sinais
18.
Nat Med ; 26(5): 712-719, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32341579

RESUMO

Atypical teratoid/rhabdoid tumors (ATRTs) typically arise in the central nervous system (CNS) of children under 3 years of age. Despite intensive multimodal therapy (surgery, chemotherapy and, if age permits, radiotherapy), median survival is 17 months1,2. We show that ATRTs robustly express B7-H3/CD276 that does not result from the inactivating mutations in SMARCB1 (refs. 3,4), which drive oncogenesis in ATRT, but requires residual SWItch/Sucrose Non-Fermentable (SWI/SNF) activity mediated by BRG1/SMARCA4. Consistent with the embryonic origin of ATRT5,6, B7-H3 is highly expressed on the prenatal, but not postnatal, brain. B7-H3.BB.z-chimeric antigen receptor (CAR) T cells administered intracerebroventricularly or intratumorally mediate potent antitumor effects against cerebral ATRT xenografts in mice, with faster kinetics, greater potency and reduced systemic levels of inflammatory cytokines compared to CAR T cells administered intravenously. CAR T cells administered ICV also traffic from the CNS into the periphery; following clearance of ATRT xenografts, B7-H3.BB.z-CAR T cells administered intracerebroventricularly or intravenously mediate antigen-specific protection from tumor rechallenge, both in the brain and periphery. These results identify B7-H3 as a compelling therapeutic target for this largely incurable pediatric tumor and demonstrate important advantages of locoregional compared to systemic delivery of CAR T cells for the treatment of CNS malignancies.


Assuntos
Antígenos B7/imunologia , Neoplasias Encefálicas/terapia , Vacinas Anticâncer/administração & dosagem , Imunoterapia Adotiva/métodos , Tumor Rabdoide/terapia , Teratoma/terapia , Adulto , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Encéfalo/patologia , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Células Cultivadas , Pré-Escolar , Feminino , Feto/patologia , Humanos , Lactente , Injeções Intraventriculares , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Receptores de Antígenos Quiméricos/administração & dosagem , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia , Tumor Rabdoide/imunologia , Tumor Rabdoide/patologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/transplante , Teratoma/imunologia , Teratoma/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
19.
PLoS One ; 15(9): e0237792, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881892

RESUMO

BACKGROUND: Ewing sarcoma (EwS) is a rare, aggressive solid tumor of childhood, adolescence and young adulthood associated with pathognomonic EWSR1-ETS fusion oncoproteins altering transcriptional regulation. Genome-wide association studies (GWAS) have identified 6 common germline susceptibility loci but have not investigated low-frequency inherited variants with minor allele frequencies below 5% due to limited genotyped cases of this rare tumor. METHODS: We investigated the contribution of rare and low-frequency variation to EwS susceptibility in the largest EwS genome-wide association study to date (733 EwS cases and 1,346 unaffected controls of European ancestry). RESULTS: We identified two low-frequency variants, rs112837127 and rs2296730, on chromosome 20 that were associated with EwS risk (OR = 0.186 and 2.038, respectively; P-value < 5×10-8) and located near previously reported common susceptibility loci. After adjusting for the most associated common variant at the locus, only rs112837127 remained a statistically significant independent signal (OR = 0.200, P-value = 5.84×10-8). CONCLUSIONS: These findings suggest rare variation residing on common haplotypes are important contributors to EwS risk. IMPACT: Motivate future targeted sequencing studies for a comprehensive evaluation of low-frequency and rare variation around common EwS susceptibility loci.


Assuntos
Loci Gênicos , Predisposição Genética para Doença , Variação Genética , Células Germinativas/metabolismo , Sarcoma de Ewing/genética , Estudo de Associação Genômica Ampla , Humanos , Desequilíbrio de Ligação/genética , Razão de Chances , Polimorfismo de Nucleotídeo Único/genética
20.
Nat Commun ; 9(1): 3184, 2018 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-30093639

RESUMO

Ewing sarcoma (EWS) is a pediatric cancer characterized by the EWSR1-FLI1 fusion. We performed a genome-wide association study of 733 EWS cases and 1346 unaffected individuals of European ancestry. Our study replicates previously reported susceptibility loci at 1p36.22, 10q21.3 and 15q15.1, and identifies new loci at 6p25.1, 20p11.22 and 20p11.23. Effect estimates exhibit odds ratios in excess of 1.7, which is high for cancer GWAS, and striking in light of the rarity of EWS cases in familial cancer syndromes. Expression quantitative trait locus (eQTL) analyses identify candidate genes at 6p25.1 (RREB1) and 20p11.23 (KIZ). The 20p11.22 locus is near NKX2-2, a highly overexpressed gene in EWS. Interestingly, most loci reside near GGAA repeat sequences and may disrupt binding of the EWSR1-FLI1 fusion protein. The high locus to case discovery ratio from 733 EWS cases suggests a genetic architecture in which moderate risk SNPs constitute a significant fraction of risk.


Assuntos
Perfilação da Expressão Gênica , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Sarcoma de Ewing/genética , Alelos , Proteínas de Ciclo Celular/genética , Proliferação de Células/genética , Proteínas de Ligação a DNA/genética , Regulação Neoplásica da Expressão Gênica , Genótipo , Proteína Homeobox Nkx-2.2 , Proteínas de Homeodomínio/genética , Humanos , Proteínas Nucleares , Proteínas de Fusão Oncogênica/genética , Polimorfismo de Nucleotídeo Único , Proteína Proto-Oncogênica c-fli-1/genética , Controle de Qualidade , Locos de Características Quantitativas , Proteína EWS de Ligação a RNA/genética , Risco , Sarcoma de Ewing/etnologia , Fatores de Transcrição/genética , População Branca , Proteínas de Peixe-Zebra
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