RESUMO
Immunodeficiency-associated primary CNS lymphoma (PCNSL) represents a distinct clinicopathological entity, which is typically Epstein-Barr virus-positive (EBV+) and carries an inferior prognosis. Genetic alterations that characterize EBV-related CNS lymphomagenesis remain unclear precluding molecular classification and targeted therapies. In this study, a comprehensive genetic analysis of 22 EBV+ PCNSL, therefore, integrated clinical and pathological information with exome and RNA sequencing (RNASeq) data. EBV+ PCNSL with germline controls carried a median of 55 protein-coding single nucleotide variants (SNVs; range 24-217) and 2 insertions/deletions (range 0-22). Genetic landscape was largely shaped by aberrant somatic hypermutation with a median of 41.01% (range 31.79-53.49%) of SNVs mapping to its target motifs. Tumors lacked established SNVs (MYD88, CD79B, PIM1) and copy number variants (CDKN2A, HLA loss) driving EBV- PCNSL. Instead, EBV+ PCNSL were characterized by SOCS1 mutations (26%), predicted to disinhibit JAK/STAT signaling, and mutually exclusive gain-of-function NOTCH pathway SNVs (26%). Copy number gains were enriched on 11q23.3, a locus directly targeted for chromosomal aberrations by EBV, that includes SIK3 known to protect from cytotoxic T-cell responses. Losses covered 5q31.2 (STING), critical for sensing viral DNA, and 17q11 (NF1). Unsupervised clustering of RNASeq data revealed two distinct transcriptional groups, that shared strong expression of CD70 and IL1R2, previously linked to tolerogenic tumor microenvironments. Correspondingly, deconvolution of bulk RNASeq data revealed elevated M2-macrophage, T-regulatory cell, mast cell and monocyte fractions in EBV+ PCNSL. In addition to novel insights into the pathobiology of EBV+ PCNSL, the data provide the rationale for the exploration of targeted therapies including JAK-, NOTCH- and CD70-directed approaches.
Assuntos
Infecções por Vírus Epstein-Barr , Linfoma , Humanos , Herpesvirus Humano 4/genética , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/metabolismo , Mutação , Prognóstico , Linfoma/genética , Microambiente TumoralRESUMO
Orchestration of inflammation and tissue repair processes is critical to maintaining homeostasis upon tissue injury. Tissue fibrosis is a pathological process characterized by aberrant accumulation of extracellular matrix proteins, such as collagen, upon injury. Dickkopf1 (DKK1) is a quintessential Wnt antagonist. The role of DKK1 in bleomycin (BLM)-induced lung injury and fibrosis model remains elusive. This study shows that BLM-induced lung injury markedly elevated DKK1 protein expressions in the lungs in mice, consistent with human pulmonary fibrosis patient lung tissues. The elevated DKK1 levels coincided with immune cell infiltration and collagen deposition. Notably, the reduced expression of DKK1 in Dkk1 hypomorphic doubleridge (Dkk1d/d) mice abrogated BLM-induced lung inflammation and fibrosis. Immune cell infiltration, collagen deposition, expression of profibrotic cytokine transforming growth factor ß1 (TGF-ß1), and extracellular matrix protein-producing myofibroblast marker α-smooth muscle actin (α-SMA) were reduced in Dkk1d/d mice. Consistent with these results, local DKK1 antibody administration after BLM-induced lung injury substantially decreased lung inflammation and fibrosis phenotypes. Taken together, these results demonstrate that DKK1 is a proinflammatory and profibrotic ligand that promotes inflammation and fibrosis upon BLM-induced lung injury, placing it as an attractive molecular target for dysregulated pulmonary inflammation and tissue repair.
Assuntos
Lesão Pulmonar , Pneumonia , Fibrose Pulmonar , Humanos , Camundongos , Animais , Fibrose Pulmonar/patologia , Bleomicina/toxicidade , Lesão Pulmonar/patologia , Pulmão/patologia , Fator de Crescimento Transformador beta1/metabolismo , Colágeno/metabolismo , Pneumonia/metabolismo , Inflamação/patologiaRESUMO
While somatic variants of TRAF7 (Tumor necrosis factor receptor-associated factor 7) underlie anterior skull-base meningiomas, here we report the inherited mutations of TRAF7 that cause congenital heart defects. We show that TRAF7 mutants operate in a dominant manner, inhibiting protein function via heterodimerization with wild-type protein. Further, the shared genetics of the two disparate pathologies can be traced to the common origin of forebrain meninges and cardiac outflow tract from the TRAF7-expressing neural crest. Somatic and inherited mutations disrupt TRAF7-IFT57 interactions leading to cilia degradation. TRAF7-mutant meningioma primary cultures lack cilia, and TRAF7 knockdown causes cardiac, craniofacial, and ciliary defects in Xenopus and zebrafish, suggesting a mechanistic convergence for TRAF7-driven meningiomas and developmental heart defects.
Assuntos
Cardiopatias Congênitas , Neoplasias Meníngeas , Meningioma , Animais , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Cardiopatias Congênitas/genética , Neoplasias Meníngeas/genética , Meningioma/genética , Meningioma/patologia , Mutação , Crânio/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Humanos , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose TumoralRESUMO
Immune responses are crucial to maintaining tissue homeostasis upon tissue injury. Upon various types of challenges, macrophages play a central role in regulating inflammation and tissue repair processes. While an immunomodulatory role of Wnt antagonist Dickkopf1 (DKK1) has been implicated, the role of Wnt antagonist DKK1 in regulating macrophage polarization in inflammation and the tissue repair process remains elusive. Here we found that DKK1 induces gene expression profiles to promote inflammation and tissue repair in macrophages. Importantly, DKK1 induced various genes, including inflammation and tissue repair, via JNK (c-jun N-terminal kinase) in macrophages. Furthermore, DKK1 potentiated IL-13-mediated macrophage polarization and activation. The co-inhibition of JNK and STAT6 markedly decreased gene expressions relevant to inflammation and fibrosis by DKK1 and IL-13. Interestingly, thrombocyte-specific deletion of DKK1 in mice reduced collagen deposition and decreased Arg1, CD206, HIF1α, and IL1ß protein expressions in monocyte-derived alveolar macrophages in the acute sterile bleomycin (BLM)-induced lung injury model. These data suggested that thrombocytes communicate with macrophages via DKK1 to orchestrate inflammation and repair in this model. Taken together, our study demonstrates DKK1's role as an important regulatory ligand for macrophage polarization in the injury-induced inflammation and repair process in the lung.
Assuntos
Lesão Pulmonar Aguda , Plaquetas , Macrófagos , Animais , Camundongos , Lesão Pulmonar Aguda/metabolismo , Bleomicina/efeitos adversos , Plaquetas/metabolismo , Inflamação , Interleucina-13/metabolismoRESUMO
Intracranial aneurysm (IA) rupture leads to subarachnoid hemorrhage, a sudden-onset disease that often causes death or severe disability. Although genome-wide association studies have identified common genetic variants that increase IA risk moderately, the contribution of variants with large effect remains poorly defined. Using whole-exome sequencing, we identified significant enrichment of rare, deleterious mutations in PPIL4, encoding peptidyl-prolyl cis-trans isomerase-like 4, in both familial and index IA cases. Ppil4 depletion in vertebrate models causes intracerebral hemorrhage, defects in cerebrovascular morphology and impaired Wnt signaling. Wild-type, but not IA-mutant, PPIL4 potentiates Wnt signaling by binding JMJD6, a known angiogenesis regulator and Wnt activator. These findings identify a novel PPIL4-dependent Wnt signaling mechanism involved in brain-specific angiogenesis and maintenance of cerebrovascular integrity and implicate PPIL4 gene mutations in the pathogenesis of IA.
Assuntos
Encéfalo/irrigação sanguínea , Ciclofilinas/genética , Aneurisma Intracraniano/genética , Neovascularização Patológica/genética , Proteínas de Ligação a RNA/genética , Ciclofilinas/fisiologia , Humanos , Mutação , Proteínas de Ligação a RNA/fisiologia , Sequenciamento do Exoma , Via de Sinalização Wnt/fisiologiaRESUMO
SLIT2 constitutes a known tumour suppressor gene, which has not yet been implicated in the pathogenesis of primary central nervous system lymphoma (PCNSL). Performing exome sequencing on paired blood and tumour DNA samples from six treatment-naïve PCNSL patients, we identified novel SLIT2 variants (p.N63S, p.T590M, p.T732S) that were associated with shorter progression-free survival in our cohort and shorter overall survival in a large validation cohort of lymphoid malignancies from the cBio Cancer Genomics Portal. WNT- and NF-κB-reporter luciferase assays suggest detected alterations are loss-of-function variants. Given the possible prognostic implications, the role of SLIT2 in PCNSL pathogenesis and progression warrants further investigation.
Assuntos
Neoplasias do Sistema Nervoso Central/genética , Sequenciamento do Exoma/métodos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Linfoma não Hodgkin/genética , Proteínas do Tecido Nervoso/genética , Neoplasias do Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/virologia , Estudos de Coortes , Feminino , Variação Estrutural do Genoma/genética , Genômica/métodos , Herpesvirus Humano 4/genética , Humanos , Linfoma não Hodgkin/diagnóstico , Linfoma não Hodgkin/tratamento farmacológico , Linfoma não Hodgkin/mortalidade , Masculino , NF-kappa B/genética , Prognóstico , Intervalo Livre de Progressão , Estudos RetrospectivosRESUMO
This corrects the article DOI: 10.1038/ncomms14433.
RESUMO
Induction of tolerance is a key mechanism to maintain or to restore immunological homeostasis. Here we show that Foxp3+ regulatory T (Treg) cells use Dickkopf-1 (DKK-1) to regulate T-cell-mediated tolerance in the T-cell-mediated autoimmune colitis model. Treg cells from DKK-1 hypomorphic doubleridge mice failed to control CD4+ T-cell proliferation, resulting in CD4 T-cell-mediated autoimmune colitis. Thymus-derived Treg cells showed a robust expression of DKK-1 but not in naive or effector CD4 T cells. DKK-1 expression in Foxp3+ Treg cells was further increased upon T-cell receptor stimulation in vitro and in vivo. Interestingly, Foxp3+ Treg cells expressed DKK-1 in the cell membrane and the functional inhibition of DKK-1 using DKK-1 monoclonal antibody abrogated the suppressor function of Foxp3+ Treg cells. DKK-1 expression was dependent on de novo protein synthesis and regulated by the mitogen-activated protein kinase pathway but not by the canonical Wnt pathway. Taken together, our results highlight membrane-bound DKK-1 as a novel Treg-derived mediator to maintain immunological tolerance in T-cell-mediated autoimmune colitis.
Assuntos
Doenças Autoimunes/metabolismo , Membrana Celular/metabolismo , Colite/metabolismo , Colo/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Tolerância a Antígenos Próprios , Linfócitos T Reguladores/metabolismo , Transferência Adotiva , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Autoimunidade , Células CHO , Membrana Celular/imunologia , Proliferação de Células , Colite/genética , Colite/imunologia , Colite/patologia , Colo/imunologia , Colo/patologia , Cricetulus , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/imunologia , Predisposição Genética para Doença , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Ativação Linfocitária , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fenótipo , Transdução de Sinais , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/transplante , Fatores de Tempo , TransfecçãoRESUMO
Meningiomas are mostly benign brain tumours, with a potential for becoming atypical or malignant. On the basis of comprehensive genomic, transcriptomic and epigenomic analyses, we compared benign meningiomas to atypical ones. Here, we show that the majority of primary (de novo) atypical meningiomas display loss of NF2, which co-occurs either with genomic instability or recurrent SMARCB1 mutations. These tumours harbour increased H3K27me3 signal and a hypermethylated phenotype, mainly occupying the polycomb repressive complex 2 (PRC2) binding sites in human embryonic stem cells, thereby phenocopying a more primitive cellular state. Consistent with this observation, atypical meningiomas exhibit upregulation of EZH2, the catalytic subunit of the PRC2 complex, as well as the E2F2 and FOXM1 transcriptional networks. Importantly, these primary atypical meningiomas do not harbour TERT promoter mutations, which have been reported in atypical tumours that progressed from benign ones. Our results establish the genomic landscape of primary atypical meningiomas and potential therapeutic targets.
Assuntos
Redes Reguladoras de Genes/genética , Redes Reguladoras de Genes/fisiologia , Genoma , Genômica/métodos , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/metabolismo , Meningioma/genética , Meningioma/metabolismo , Sítios de Ligação , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Transformação Celular Neoplásica/genética , Instabilidade Cromossômica , Análise por Conglomerados , Metilação de DNA , Fator de Transcrição E2F2/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigenômica/métodos , Exoma/genética , Proteína Forkhead Box M1/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Genes da Neurofibromatose 2 , Técnicas de Genotipagem , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Técnicas de Sonda Molecular , Mutação , Fenótipo , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Proteína SMARCB1/genética , Análise de Sequência , Transdução de Sinais/genética , TranscriptomaRESUMO
BACKGROUND: Glioblastoma multiforme (GBM) constitutes nearly half of all malignant brain tumors and has a median survival of 15 months. The standard treatment for these lesions includes maximal resection, radiotherapy, and chemotherapy; however, individual tumors display immense variability in their response to these approaches. Genomic techniques such as whole-exome sequencing (WES) provide an opportunity to understand the molecular basis of this variability. METHODS: Here, we report WES-guided treatment of a patient with a primary GBM and two subsequent recurrences, demonstrating the dynamic nature of treatment-induced molecular changes and their implications for clinical decision-making. We also analyze the Yale-Glioma cohort, composed of 110 whole exome- or whole genome-sequenced tumor-normal pairs, to assess the frequency of genomic events found in the presented case. RESULTS: Our longitudinal analysis revealed how the genomic profile evolved under the pressure of therapy. Specifically targeted approaches eradicated treatment-sensitive clones while enriching for resistant ones, generated due to chromothripsis, which we show to be a frequent event in GBMs based on our extended analysis of 110 gliomas in the Yale-Glioma cohort. Despite chromothripsis and the later acquired mismatch-repair deficiency, genomics-guided personalized treatment extended survival to over 5 years. Interestingly, the case displayed a favorable response to immune checkpoint inhibition after acquiring mismatch repair deficiency. CONCLUSIONS: Our study demonstrates the importance of longitudinal genomic profiling to adjust to the dynamic nature of treatment-induced molecular changes to improve the outcomes of precision therapies.
Assuntos
Aberrações Cromossômicas , Genômica , Glioblastoma/terapia , Recidiva Local de Neoplasia , Medicina de Precisão , Antineoplásicos/uso terapêutico , Terapia Combinada , Reparo de Erro de Pareamento de DNA , Análise Mutacional de DNA , DNA de Neoplasias , Progressão da Doença , Exoma , Feminino , Cirurgia Geral , Genoma Humano , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Imunoterapia , Estudos Longitudinais , Pessoa de Meia-Idade , Mutação , Radioterapia , Resultado do TratamentoRESUMO
RNA polymerase II mediates the transcription of all protein-coding genes in eukaryotic cells, a process that is fundamental to life. Genomic mutations altering this enzyme have not previously been linked to any pathology in humans, which is a testament to its indispensable role in cell biology. On the basis of a combination of next-generation genomic analyses of 775 meningiomas, we report that recurrent somatic p.Gln403Lys or p.Leu438_His439del mutations in POLR2A, which encodes the catalytic subunit of RNA polymerase II (ref. 1), hijack this essential enzyme and drive neoplasia. POLR2A mutant tumors show dysregulation of key meningeal identity genes, including WNT6 and ZIC1/ZIC4. In addition to mutations in POLR2A, NF2, SMARCB1, TRAF7, KLF4, AKT1, PIK3CA, and SMO, we also report somatic mutations in AKT3, PIK3R1, PRKAR1A, and SUFU in meningiomas. Our results identify a role for essential transcriptional machinery in driving tumorigenesis and define mutually exclusive meningioma subgroups with distinct clinical and pathological features.
Assuntos
Neoplasias Meníngeas/genética , Meningioma/genética , Mutação , RNA Polimerase II/genética , Domínio Catalítico/genética , Cromossomos Humanos Par 22 , Estudos de Coortes , Análise Mutacional de DNA , Elementos Facilitadores Genéticos , Exoma , Regulação Neoplásica da Expressão Gênica , Genótipo , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Neoplasias Meníngeas/classificação , Meningioma/classificação , Neurofibromina 2/genética , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral/genéticaRESUMO
The single nucleotide polymorphism rs55705857, located in a non-coding but evolutionarily conserved region at 8q24.21, is strongly associated with IDH-mutant glioma development and was suggested to be a causal variant. However, the molecular mechanism underlying this association has remained unknown. With a case control study in 285 gliomas, 316 healthy controls, 380 systemic cancers, 31 other CNS-tumors, and 120 IDH-mutant cartilaginous tumors, we identified that the association was specific to IDH-mutant gliomas. Odds-ratios were 9.25 (5.17-16.52; 95% CI) for IDH-mutated gliomas and 12.85 (5.94-27.83; 95% CI) for IDH-mutated, 1p/19q co-deleted gliomas. Decreasing strength with increasing anaplasia implied a modulatory effect. No somatic mutations were noted at this locus in 114 blood-tumor pairs, nor was there a copy number difference between risk-allele and only-ancestral allele carriers. CCDC26 RNA-expression was rare and not different between the two groups. There were only minor subtype-specific differences in common glioma driver genes. RNA sequencing and LC-MS/MS comparisons pointed to significantly altered MYC-signaling. Baseline enhancer activity of the conserved region specifically on the MYC promoter and its further positive modulation by the SNP risk-allele was shown in vitro. Our findings implicate MYC deregulation as the underlying cause of the observed association.
Assuntos
Biomarcadores Tumorais/genética , Estudos de Associação Genética , Glioma/genética , Proteínas Proto-Oncogênicas c-myc/genética , Adulto , Idoso , Alelos , Feminino , Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Glioma/patologia , Humanos , Isocitrato Desidrogenase/genética , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mutação , Gradação de Tumores , Proteínas de Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Proteômica , Análise de Sequência de RNARESUMO
Exposure to a plethora of environmental challenges commonly triggers pathological type 2 cell-mediated inflammation. Here we report the pathological role of the Wnt antagonist Dickkopf-1 (Dkk-1) upon allergen challenge or non-healing parasitic infection. The increased circulating amounts of Dkk-1 polarized T cells to T helper 2 (Th2) cells, stimulating a marked simultaneous induction of the transcription factors c-Maf and Gata-3, mediated by the kinases p38 MAPK and SGK-1, resulting in Th2 cell cytokine production. Circulating Dkk-1 was primarily from platelets, and the increase of Dkk-1 resulted in formation of leukocyte-platelet aggregates (LPA) that facilitated leukocyte infiltration to the affected tissue. Functional inhibition of Dkk-1 impaired Th2 cell cytokine production and leukocyte infiltration, protecting mice from house dust mite (HDM)-induced asthma or Leishmania major infection. These results highlight that Dkk-1 from thrombocytes is an important regulator of leukocyte infiltration and polarization of immune responses in pathological type 2 cell-mediated inflammation.
Assuntos
Asma/imunologia , Plaquetas/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Leishmania major/imunologia , Leishmaniose Cutânea/imunologia , Células Th2/imunologia , Proteínas Wnt/antagonistas & inibidores , Animais , Antígenos de Dermatophagoides/imunologia , Antígenos de Protozoários/imunologia , Diferenciação Celular , Células Cultivadas , Citocinas/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica , Humanos , Inflamação/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Animais , Pyroglyphidae , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
The fat mass and obesity associated (FTO) gene has previously been associated with a variety of diseases and conditions, notably obesity, acute coronary syndrome and metabolic syndrome. Reports describing mutations in FTO as well as in FTO animal models have further demonstrated a role for FTO in the development of the brain and other organs. Here, we describe a patient born of consanguineous union who presented with microcephaly, developmental delay, behavioral abnormalities, dysmorphic facial features, hypotonia and other various phenotypic abnormalities. Whole-exome sequencing revealed a novel homozygous missense mutation in FTO and a nonsense mutation in the cholesteryl ester transfer protein (CETP). Exome copy number variation analysis revealed no disease-causing large duplications or deletions within coding regions. Patient's, her parents' and non-related control' fibroblasts were analyzed for morphologic defects, abnormal proliferation, apoptosis and transcriptome profile. We have shown that FTO is located in the nucleus of cells from each tested sample. Western blot analysis demonstrated no changes in patient FTO. Quantitative (qPCR) analysis revealed slightly decreased levels of FTO expression in patient cells compared with controls. No morphological or proliferation differences between the patient and control fibroblasts were observed. There is still much to be learned about the molecular mechanisms by which mutations in FTO contribute to such severe phenotypes.
Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Proteínas de Transferência de Ésteres de Colesterol/genética , Estudos de Associação Genética , Homozigoto , Mutação de Sentido Incorreto , Apoptose/genética , Biópsia , Pré-Escolar , Biologia Computacional/métodos , Consanguinidade , Variações do Número de Cópias de DNA , Análise Mutacional de DNA , Exoma , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Fenótipo , TranscriptomaRESUMO
Gliomas represent approximately 30% of all central nervous system tumors and 80% of malignant brain tumors. To understand the molecular mechanisms underlying the malignant progression of low-grade gliomas with mutations in IDH1 (encoding isocitrate dehydrogenase 1), we studied paired tumor samples from 41 patients, comparing higher-grade, progressed samples to their lower-grade counterparts. Integrated genomic analyses, including whole-exome sequencing and copy number, gene expression and DNA methylation profiling, demonstrated nonlinear clonal expansion of the original tumors and identified oncogenic pathways driving progression. These include activation of the MYC and RTK-RAS-PI3K pathways and upregulation of the FOXM1- and E2F2-mediated cell cycle transitions, as well as epigenetic silencing of developmental transcription factor genes bound by Polycomb repressive complex 2 in human embryonic stem cells. Our results not only provide mechanistic insight into the genetic and epigenetic mechanisms driving glioma progression but also identify inhibition of the bromodomain and extraterminal (BET) family as a potential therapeutic approach.
Assuntos
Neoplasias do Sistema Nervoso Central/genética , Glioma/genética , Isocitrato Desidrogenase/genética , Mutação , Neoplasias do Sistema Nervoso Central/patologia , Metilação de DNA , Células-Tronco Embrionárias/metabolismo , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Dosagem de Genes , Regulação Neoplásica da Expressão Gênica , Genes myc , Glioma/patologia , Humanos , Isocitrato Desidrogenase/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Receptor Notch1/genética , Receptor Notch1/metabolismoRESUMO
Exome sequencing analysis of over 2,000 children with complex malformations of cortical development identified five independent (four homozygous and one compound heterozygous) deleterious mutations in KATNB1, encoding the regulatory subunit of the microtubule-severing enzyme Katanin. Mitotic spindle formation is defective in patient-derived fibroblasts, a consequence of disrupted interactions of mutant KATNB1 with KATNA1, the catalytic subunit of Katanin, and other microtubule-associated proteins. Loss of KATNB1 orthologs in zebrafish (katnb1) and flies (kat80) results in microcephaly, recapitulating the human phenotype. In the developing Drosophila optic lobe, kat80 loss specifically affects the asymmetrically dividing neuroblasts, which display supernumerary centrosomes and spindle abnormalities during mitosis, leading to cell cycle progression delays and reduced cell numbers. Furthermore, kat80 depletion results in dendritic arborization defects in sensory and motor neurons, affecting neural architecture. Taken together, we provide insight into the mechanisms by which KATNB1 mutations cause human cerebral cortical malformations, demonstrating its fundamental role during brain development.
Assuntos
Adenosina Trifosfatases/genética , Encéfalo/anormalidades , Encéfalo/patologia , Microcefalia/genética , Células-Tronco Neurais/patologia , Neurogênese/genética , Lobo Óptico de Animais não Mamíferos/anormalidades , Animais , Encéfalo/crescimento & desenvolvimento , Contagem de Células , Divisão Celular/genética , Dendritos/genética , Drosophila , Proteínas de Drosophila/genética , Humanos , Katanina , Camundongos , Microcefalia/patologia , Proteínas Associadas aos Microtúbulos/genética , Mutação , Fuso Acromático/genética , Peixe-ZebraRESUMO
The receptor for glycation end products (RAGE) has been previously implicated in shaping the adaptive immune response. RAGE is expressed in T cells after activation and constitutively in T cells from patients with diabetes. The effects of RAGE on adaptive immune responses are not clear: Previous reports show that RAGE blockade affects Th1 responses. To clarify the role of RAGE in adaptive immune responses and the mechanisms of its effects, we examined whether RAGE plays a role in T cell activation in a Th2 response involving ovalbumin (OVA)-induced asthma in mice. WT and RAGE deficient wild-type and OT-II mice, expressing a T cell receptor specific for OVA, were immunized intranasally with OVA. Lung cellular infiltration and T cell responses were analyzed by immunostaining, FACS, and multiplex bead analyses for cytokines. RAGE deficient mice showed reduced cellular infiltration in the bronchial alveolar lavage fluid and impaired T cell activation in the mediastinal lymph nodes when compared with WT mice. In addition, RAGE deficiency resulted in reduced OT-II T cell infiltration of the lung and impaired IFNγ and IL-5 production when compared with WT mice and reduced infiltration when transferred into WT hosts. When cultured under conditions favoring the differentiation of T cells subsets, RAGE deficient T cells showed reduced production of IFNγ but increased production of IL-17. Our data show a stimulatory role for RAGE in T activation in OVA-induced asthma. This role is largely mediated by the effects of RAGE on T cell proliferation and differentiation. These findings suggest that RAGE may play a regulatory role in T cell responses following immune activation.
Assuntos
Asma/induzido quimicamente , Asma/metabolismo , Ovalbumina/toxicidade , Receptores Imunológicos/metabolismo , Animais , Asma/genética , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Feminino , Interferon gama/metabolismo , Interleucina-17/metabolismo , Interleucina-5/metabolismo , Camundongos , Receptor para Produtos Finais de Glicação Avançada , Receptores Imunológicos/genética , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/metabolismo , Células Th2/citologia , Células Th2/metabolismoRESUMO
We report genomic analysis of 300 meningiomas, the most common primary brain tumors, leading to the discovery of mutations in TRAF7, a proapoptotic E3 ubiquitin ligase, in nearly one-fourth of all meningiomas. Mutations in TRAF7 commonly occurred with a recurrent mutation (K409Q) in KLF4, a transcription factor known for its role in inducing pluripotency, or with AKT1(E17K), a mutation known to activate the PI3K pathway. SMO mutations, which activate Hedgehog signaling, were identified in ~5% of non-NF2 mutant meningiomas. These non-NF2 meningiomas were clinically distinctive-nearly always benign, with chromosomal stability, and originating from the medial skull base. In contrast, meningiomas with mutant NF2 and/or chromosome 22 loss were more likely to be atypical, showing genomic instability, and localizing to the cerebral and cerebellar hemispheres. Collectively, these findings identify distinct meningioma subtypes, suggesting avenues for targeted therapeutics.