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1.
EMBO Rep ; 25(1): 168-197, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38225354

RESUMO

Cell commitment to tumourigenesis and the onset of uncontrolled growth are critical determinants in cancer development but the early events directing tumour initiating cell (TIC) fate remain unclear. We reveal a single-cell transcriptome profile of brain TICs transitioning into tumour growth using the brain tumour (brat) neural stem cell-based Drosophila model. Prominent changes in metabolic and proteostasis-associated processes including ribogenesis are identified. Increased ribogenesis is a known cell adaptation in established tumours. Here we propose that brain TICs boost ribogenesis prior to tumour growth. In brat-deficient TICs, we show that this dramatic change is mediated by upregulated HEAT-Repeat Containing 1 (HEATR1) to promote ribosomal RNA generation, TIC enlargement and onset of overgrowth. High HEATR1 expression correlates with poor glioma patient survival and patient-derived glioblastoma stem cells rely on HEATR1 for enhanced ribogenesis and tumourigenic potential. Finally, we show that HEATR1 binds the master growth regulator MYC, promotes its nucleolar localisation and appears required for MYC-driven ribogenesis, suggesting a mechanism co-opted in ribogenesis reprogramming during early brain TIC development.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Antígenos de Histocompatibilidade Menor , Proteínas Proto-Oncogênicas c-myc , Proteínas de Ligação a RNA , Animais , Humanos , Encéfalo/metabolismo , Neoplasias Encefálicas/metabolismo , Carcinogênese/patologia , Transformação Celular Neoplásica/patologia , Proteínas de Ligação a DNA/metabolismo , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Glioblastoma/metabolismo , Glioma/patologia , Antígenos de Histocompatibilidade Menor/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo
2.
Cell ; 140(4): 477-90, 2010 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-20178741

RESUMO

Current models imply that the FERM domain protein Merlin, encoded by the tumor suppressor NF2, inhibits mitogenic signaling at or near the plasma membrane. Here, we show that the closed, growth-inhibitory form of Merlin accumulates in the nucleus, binds to the E3 ubiquitin ligase CRL4(DCAF1), and suppresses its activity. Depletion of DCAF1 blocks the promitogenic effect of inactivation of Merlin. Conversely, enforced expression of a Merlin-insensitive mutant of DCAF1 counteracts the antimitogenic effect of Merlin. Re-expression of Merlin and silencing of DCAF1 implement a similar, tumor-suppressive program of gene expression. Tumor-derived mutations invariably disrupt Merlin's ability to interact with or inhibit CRL4(DCAF1). Finally, depletion of DCAF1 inhibits the hyperproliferation of Schwannoma cells from NF2 patients and suppresses the oncogenic potential of Merlin-deficient tumor cell lines. We propose that Merlin suppresses tumorigenesis by translocating to the nucleus to inhibit CRL4(DCAF1).


Assuntos
Proteínas de Transporte/metabolismo , Genes Supressores de Tumor , Mesotelioma/metabolismo , Neurilemoma/metabolismo , Neurofibromina 2/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Proteínas de Transporte/química , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células , Células Cultivadas , Humanos , Modelos Moleculares , Proteínas Serina-Treonina Quinases , Ubiquitina-Proteína Ligases
3.
Neuropathol Appl Neurobiol ; 50(2): e12979, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38605644

RESUMO

In 2015, a groundswell of brain tumour patient, carer and charity activism compelled the UK Minister for Life Sciences to form a brain tumour research task and finish group. This resulted, in 2018, with the UK government pledging £20m of funding, to be paralleled with £25m from Cancer Research UK, specifically for neuro-oncology research over the subsequent 5 years. Herein, we review if and how the adult brain tumour research landscape in the United Kingdom has changed over that time and what challenges and bottlenecks remain. We have identified seven universal brain tumour research priorities and three cross-cutting themes, which span the research spectrum from bench to bedside and back again. We discuss the status, challenges and recommendations for each one, specific to the United Kingdom.


Assuntos
Pesquisa Biomédica , Neoplasias Encefálicas , Adulto , Humanos , Reino Unido
4.
Brain ; 146(4): 1697-1713, 2023 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-36148553

RESUMO

Schwannoma tumours typically arise on the eighth cranial nerve and are mostly caused by loss of the tumour suppressor Merlin (NF2). There are no approved chemotherapies for these tumours and the surgical removal of the tumour carries a high risk of damage to the eighth or other close cranial nerve tissue. New treatments for schwannoma and other NF2-null tumours such as meningioma are urgently required. Using a combination of human primary tumour cells and mouse models of schwannoma, we have examined the role of the Hippo signalling pathway in driving tumour cell growth. Using both genetic ablation of the Hippo effectors YAP and TAZ as well as novel TEAD palmitoylation inhibitors, we show that Hippo signalling may be successfully targeted in vitro and in vivo to both block and, remarkably, regress schwannoma tumour growth. In particular, successful use of TEAD palmitoylation inhibitors in a preclinical mouse model of schwannoma points to their potential future clinical use. We also identify the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) as a Hippo signalling target, driven by the TAZ protein in human and mouse NF2-null schwannoma cells, as well as in NF2-null meningioma cells, and examine the potential future role of this new target in halting schwannoma and meningioma tumour growth.


Assuntos
Neoplasias Meníngeas , Meningioma , Neurilemoma , Animais , Humanos , Camundongos , Proliferação de Células , Neurilemoma/genética , Neurilemoma/patologia , Neurofibromina 2/genética , Neurofibromina 2/metabolismo , Proteínas de Sinalização YAP/metabolismo , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional/metabolismo , Fatores de Transcrição de Domínio TEA/metabolismo
5.
Clin Trials ; 21(1): 40-50, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37904489

RESUMO

INTRODUCTION: Neurofibromatosis 1 and schwannomatosis are characterized by potential lifelong morbidity and life-threatening complications. To date, however, diagnostic and predictive biomarkers are an unmet need in this patient population. The inclusion of biomarker discovery correlatives in neurofibromatosis 1/schwannomatosis clinical trials enables study of low-incidence disease. The implementation of a common data model would further enhance biomarker discovery by enabling effective concatenation of data from multiple studies. METHODS: The Response Evaluation in Neurofibromatosis and Schwannomatosis biomarker working group reviewed published data on emerging trends in neurofibromatosis 1 and schwannomatosis biomarker research and developed recommendations in a series of consensus meetings. RESULTS: Liquid biopsy has emerged as a promising assay for neurofibromatosis 1/schwannomatosis biomarker discovery and validation. In addition, we review recommendations for a range of biomarkers in clinical trials, neurofibromatosis 1/schwannomatosis-specific data annotations, and common data models for data integration. CONCLUSION: These Response Evaluation in Neurofibromatosis and Schwannomatosis consensus guidelines are intended to provide best practices for the inclusion of biomarker studies in neurofibromatosis 1/schwannomatosis clinical trials, data, and sample annotation and to lay a framework for data harmonization and concatenation between trials.


Assuntos
Neurilemoma , Neurofibromatoses , Neurofibromatose 1 , Neurofibromatose 2 , Neoplasias Cutâneas , Humanos , Neurofibromatose 1/diagnóstico , Neurofibromatose 2/diagnóstico , Neurofibromatose 2/patologia , Neurofibromatoses/diagnóstico , Neurofibromatoses/terapia , Neurofibromatoses/patologia , Biomarcadores
6.
Adv Exp Med Biol ; 1416: 199-211, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37432629

RESUMO

The management of clinically aggressive meningiomas remains challenging due to limited treatment options aside from surgical removal and radiotherapy. High recurrence rates and lack of effective systemic therapies contribute to the unfavorable prognosis of these patients. Accurate in vitro and in vivo models are critical for understanding meningioma pathogenesis and to identify and test novel therapeutics. In this chapter, we review cell models, genetically engineered mouse models, and xenograft mouse models, with special emphasis on the field of application. Finally, promising preclinical 3D models such as organotypic tumor slices and patient-derived tumor organoids are discussed.


Assuntos
Neoplasias Meníngeas , Meningioma , Humanos , Animais , Camundongos , Meningioma/genética , Meningioma/terapia , Agressão , Modelos Animais de Doenças , Organoides , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/terapia
7.
Br J Neurosurg ; 35(6): 696-702, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34148477

RESUMO

INTRODUCTION: There are a number of prognostic markers (methylation, CDKN2A/B) described to be useful for the stratification of meningiomas. However, there are currently no clinically validated biomarkers for the preoperative prediction of meningioma grade, which is determined by the histological analysis of tissue obtained from surgery. Accurate preoperative biomarkers would inform the pre-surgical assessment of these tumours, their grade and prognosis and refine the decision-making process for treatment. This review is focused on the more controversial grade II tumours, where debate still surrounds the need for adjuvant therapy, repeat surgery and frequency of follow up. METHODS: We evaluated current literature for potential grade II meningioma clinical biomarkers, focusing on radiological, biochemical (blood assays) and immunohistochemical markers for diagnosis and prognosis, and how they can be used to differentiate them from grade I meningiomas using the post-2016 WHO classification. To do this, we conducted a PUBMED, SCOPUS, OVID SP, SciELO, and INFORMA search using the keywords; 'biomarker', 'diagnosis', 'atypical', 'meningioma', 'prognosis', 'grade I', 'grade 1', 'grade II' and 'grade 2'. RESULTS: We identified 1779 papers, 20 of which were eligible for systematic review according to the defined inclusion and exclusion criteria. From the review, we identified radiological characteristics (irregular tumour shape, tumour growth rate faster than 3cm3/year, high peri-tumoural blood flow), blood markers (low serum TIMP1/2, high serum HER2, high plasma Fibulin-2) and histological markers (low H3K27me3, low SMARCE1, low AKAP12, high ARIDB4) that may aid in differentiating grade II from grade I meningiomas. CONCLUSION: Being able to predict meningioma grade at presentation using the radiological and blood markers described may influence management as the likely grade II tumours will be followed up or treated more aggressively, while the histological markers may prognosticate progression or post-treatment recurrence. This to an extent offers a more personalised treatment approach for patients.


Assuntos
Neoplasias Meníngeas , Meningioma , Biomarcadores Tumorais , Proteínas Cromossômicas não Histona , Terapia Combinada , Proteínas de Ligação a DNA , Humanos , Neoplasias Meníngeas/diagnóstico por imagem , Neoplasias Meníngeas/cirurgia , Meningioma/diagnóstico por imagem , Meningioma/cirurgia , Recidiva Local de Neoplasia , Prognóstico
8.
Int J Mol Sci ; 22(2)2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33429944

RESUMO

There is an unmet need for the identification of biomarkers to aid in the diagnosis, clinical management, prognosis and follow-up of meningiomas. There is currently no consensus on the optimum management of WHO grade II meningiomas. In this study, we identified the calcium binding extracellular matrix glycoprotein, Fibulin-2, via mass-spectrometry-based proteomics, assessed its expression in grade I and II meningiomas and explored its potential as a grade II biomarker. A total of 87 grade I and 91 grade II different meningioma cells, tissue and plasma samples were used for the various experimental techniques employed to assess Fibulin-2 expression. The tumours were reviewed and classified according to the 2016 edition of the Classification of the Tumours of the central nervous system (CNS). Mass spectrometry proteomic analysis identified Fibulin-2 as a differentially expressed protein between grade I and II meningioma cell cultures. Fibulin-2 levels were further evaluated in meningioma cells using Western blotting and Real-time Quantitative Polymerase Chain Reaction (RT-qPCR); in meningioma tissues via immunohistochemistry and RT-qPCR; and in plasma via Enzyme-Linked Immunosorbent Assay (ELISA). Proteomic analyses (p < 0.05), Western blotting (p < 0.05) and RT-qPCR (p < 0.01) confirmed significantly higher Fibulin-2 (FBLN2) expression levels in grade II meningiomas compared to grade I. Fibulin-2 blood plasma levels were also significantly higher in grade II meningioma patients compared to grade I patients. This study suggests that elevated Fibulin-2 might be a novel grade II meningioma biomarker, when differentiating them from the grade I tumours. The trend of Fibulin-2 expression observed in plasma may serve as a useful non-invasive biomarker.


Assuntos
Biomarcadores Tumorais/sangue , Proteínas de Ligação ao Cálcio/sangue , Proteínas da Matriz Extracelular/sangue , Neoplasias Meníngeas/sangue , Meningioma/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/patologia , Meningioma/genética , Meningioma/patologia , Pessoa de Meia-Idade , Gradação de Tumores , Prognóstico , Proteômica
9.
Int J Mol Sci ; 21(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32070062

RESUMO

The majority of meningiomas are grade I, but some grade I tumours are clinically more aggressive. Recent advances in the genetic study of meningiomas has allowed investigation into the influence of genetics on the tumour microenvironment, which is important for tumorigenesis. We have established that the endpoint genotyping method Kompetitive Allele Specific PCR (KASP™) is a fast, reliable method for the screening of meningioma samples into different non-NF2 mutational groups using a standard real-time PCR instrument. This genotyping method and four-colour flow cytometry has enabled us to assess the variability in the largest immune cell infiltrate population, M2 macrophages (CD45+HLA-DR+CD14+CD163+) in 42 meningioma samples, and to suggest that underlying genetics is relevant. Further immunohistochemistry analysis comparing AKT1 E17K mutants to WHO grade I NF2-negative samples showed significantly lower levels of CD163-positive activated M2 macrophages in meningiomas with mutated AKT1 E17K, signifying a more immunosuppressive tumour microenvironment in NF2 meningiomas. Our data suggested that underlying tumour genetics play a part in the development of the immune composition of the tumour microenvironment. Stratifying meningiomas by mutational status and correlating this with their cellular composition will aid in the development of new immunotherapies for patients.


Assuntos
Macrófagos/metabolismo , Meningioma/genética , Proteínas Proto-Oncogênicas c-akt/genética , Microambiente Tumoral/genética , Alelos , Antígenos CD/genética , Antígenos de Diferenciação Mielomonocítica/genética , Linhagem da Célula/genética , Feminino , Genótipo , Antígenos HLA-DR/genética , Humanos , Antígenos Comuns de Leucócito/genética , Receptores de Lipopolissacarídeos/genética , Macrófagos/classificação , Macrófagos/patologia , Masculino , Meningioma/classificação , Meningioma/patologia , Pessoa de Meia-Idade , Mutação/genética , Neurofibromina 2/genética , Receptores de Superfície Celular/genética
10.
J Biol Chem ; 292(33): 13599-13614, 2017 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-28673965

RESUMO

Autophagy comprises the processes of autophagosome synthesis and lysosomal degradation. In certain stress conditions, increased autophagosome synthesis may be associated with decreased lysosomal activity, which may result in reduced processing of the excessive autophagosomes by the rate-limiting lysosomal activity. Thus, the excessive autophagosomes in such situations may be largely unfused to lysosomes, and their formation/accumulation under these conditions is assumed to be futile for autophagy. The role of cytotoxicity in accumulating autophagosomes (representing synthesis of autophagosomes subsequently unfused to lysosomes) has not been investigated previously. Here, we found that accumulation of autophagosomes compromised cell viability, and this effect was alleviated by depletion of autophagosome machinery proteins. We tested whether reduction in autophagosome synthesis could affect cell viability in cell models expressing mutant huntingtin and α-synuclein, given that both of these proteins cause increased autophagosome biogenesis and compromised lysosomal activity. Importantly, partial depletion of autophagosome machinery proteins Atg16L1 and Beclin 1 significantly ameliorated cell death in these conditions. Our data suggest that production/accumulation of autophagosomes subsequently unfused to lysosomes (or accumulation of autophagosomes) directly induces cellular toxicity, and this process may be implicated in the pathogenesis of neurodegenerative diseases. Therefore, lowering the accumulation of autophagosomes may represent a therapeutic strategy for tackling such diseases.


Assuntos
Autofagossomos/metabolismo , Lisossomos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Proteínas Qa-SNARE/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Autofagossomos/patologia , Autofagossomos/ultraestrutura , Linhagem Celular Tumoral , Sobrevivência Celular , Células Cultivadas , Embrião de Mamíferos/citologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Proteína 2 de Membrana Associada ao Lisossomo/genética , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Proteínas de Membrana Lisossomal/genética , Proteínas de Membrana Lisossomal/metabolismo , Lisossomos/patologia , Lisossomos/ultraestrutura , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Transmissão , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Neurônios/patologia , Neurônios/ultraestrutura , Proteínas Qa-SNARE/antagonistas & inibidores , Proteínas Qa-SNARE/genética , Interferência de RNA , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Células Tumorais Cultivadas , Proteínas de Transporte Vesicular/antagonistas & inibidores , Proteínas de Transporte Vesicular/genética
11.
Neuropathology ; 36(3): 250-61, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26554033

RESUMO

A minority of meningiomas are difficult to treat with surgery or radiotherapy, and chemotherapeutic alternatives are limited. This study aims to better understand pathways that are active in meningiomas, in order to direct future treatment strategies. We investigated the expression and activation of multiple growth factor receptors, their ligands and downstream signalling pathways in 30 meningiomas using immunohistochemistry. Expression was correlated with chromosome 22q loss. Membrane expression of VEGF receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR)ß was seen in 83% of tumors, Axl in 70%, EGFR in 50% and insulin-like growth factor receptor in 47%. Expression was similar in low- and high-grade tumors, but membrane EGFR expression was not seen in tumors showing chromosome 22q loss (P < 0.05). Expression of ligands (IGF, NRG, VEGF, Gas 6), and signalling proteins (Mek, Erk, Jnk, Akt) and pS6RP, was widespread. Western blot confirmed widespread Axl expression and supported selective expression of EGFR in NF2-intact meningiomas. The majority of meningiomas express and show activation of multiple growth factor receptors and their signalling pathways, irrespective of tumor grade. In addition to previously reported receptors, Axl offers a new therapeutic target. The findings also suggest that anti-EGFR based therapies may be less effective in meningiomas with 22q loss.


Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neoplasias Meníngeas/metabolismo , Meningioma/metabolismo , Receptores de Fatores de Crescimento/metabolismo , Transdução de Sinais , Cromossomos Humanos Par 22 , Humanos , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/patologia , Meningioma/genética , Meningioma/patologia , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Receptor Tirosina Quinase Axl
12.
Am J Med Genet A ; 167A(1): 1-10, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25393061

RESUMO

Neurofibromatosis type 1 (NF1) was the first RASopathy and is now one of many RASopathies that are caused by germline mutations in genes that encode components of the Ras/mitogen-activated protein kinase (MAPK) pathway. Their common underlying pathogenetic etiology causes significant overlap in phenotypic features which includes craniofacial dysmorphology, cardiac, cutaneous, musculoskeletal, GI and ocular abnormalities, and a predisposition to cancer. The proceedings from the symposium "Recent Developments in Neurofibromatoses (NF) and RASopathies: Management, Diagnosis and Current and Future Therapeutic Avenues" chronicle this timely and topical clinical translational research symposium. The overarching goal was to bring together clinicians, basic scientists, physician-scientists, advocate leaders, trainees, students and individuals with Ras pathway syndromes to discuss the most state-of-the-art basic science and clinical issues in an effort to spark collaborations directed towards the best practices and therapies for individuals with RASopathies.


Assuntos
Neurofibromatoses/diagnóstico , Neurofibromatoses/terapia , Proteínas ras/genética , Animais , Ensaios Clínicos como Assunto , Modelos Animais de Doenças , Humanos , Imageamento por Ressonância Magnética , Camundongos , Mutação/genética , Síndrome , Carga Tumoral
14.
Am J Med Genet A ; 164A(3): 563-78, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24443315

RESUMO

The neurofibromatoses (NF) are autosomal dominant genetic disorders that encompass the rare diseases NF1, NF2, and schwannomatosis. The NFs affect more people worldwide than Duchenne muscular dystrophy and Huntington's disease combined. NF1 and NF2 are caused by mutations of known tumor suppressor genes (NF1 and NF2, respectively). For schwannomatosis, although mutations in SMARCB1 were identified in a subpopulation of schwannomatosis patients, additional causative gene mutations are still to be discovered. Individuals with NF1 may demonstrate manifestations in multiple organ systems, including tumors of the nervous system, learning disabilities, and physical disfigurement. NF2 ultimately can cause deafness, cranial nerve deficits, and additional severe morbidities caused by tumors of the nervous system. Unmanageable pain is a key finding in patients with schwannomatosis. Although today there is no marketed treatment for NF-related tumors, a significant number of clinical trials have become available. In addition, significant preclinical efforts have led to a more rational selection of potential drug candidates for NF trials. An important element in fueling this progress is the sharing of knowledge. For over 20 years the Children's Tumor Foundation has convened an annual NF Conference, bringing together NF professionals to share novel findings, ideas, and build collaborations. The 2012 NF Conference held in New Orleans hosted over 350 NF researchers and clinicians. This article provides a synthesis of the highlights presented at the conference and as such, is a "state-of-the-field" for NF research in 2012.


Assuntos
Neurilemoma/etiologia , Neurofibromatoses/etiologia , Neurofibromatose 1/etiologia , Neurofibromatose 2/etiologia , Neoplasias Cutâneas/etiologia , Humanos , Neurilemoma/genética , Neurilemoma/terapia , Neurofibromatoses/genética , Neurofibromatoses/terapia , Neurofibromatose 1/genética , Neurofibromatose 1/terapia , Neurofibromatose 2/genética , Neurofibromatose 2/terapia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/terapia
15.
Brain ; 136(Pt 2): 549-63, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23413263

RESUMO

Loss of the Merlin tumour suppressor causes abnormal de-differentiation and proliferation of Schwann cells and formation of schwannoma tumours in patients with neurofibromatosis type 2. Within the mature peripheral nerve the normal development, differentiation and maintenance of myelinating and non-myelinating Schwann cells is regulated by a network of transcription factors that include SOX10, OCT6 (now known as POU3F1), NFATC4 and KROX20 (also known as Egr2). We have examined for the first time how their regulation of Schwann cell development is disrupted in primary human schwannoma cells. We find that induction of both KROX20 and OCT6 is impaired, whereas enforced expression of KROX20 drives both myelin gene expression and cell cycle arrest in Merlin-null cells. Importantly, we show that human schwannoma cells have reduced expression of SOX10 protein and messenger RNA. Analysis of mouse SOX10-null Schwann cells shows they display many of the characteristics of human schwannoma cells, including increased expression of platelet derived growth factor receptor beta (PDGFRB) messenger RNA and protein, enhanced proliferation, increased focal adhesions and schwannoma-like morphology. Correspondingly, reintroduction of SOX10 into human Merlin-null cells restores the ability of these cells to induce KROX20 and myelin protein zero (MPZ), localizes NFATC4 to the nucleus, reduces cell proliferation and suppresses PDGFRB expression. Thus, we propose that loss of the SOX10 protein, which is vital for normal Schwann cell development, is also key to the pathology of Merlin-null schwannoma tumours.


Assuntos
Técnicas de Silenciamento de Genes , Neurilemoma/genética , Neurofibromatose 2/genética , Neurofibromina 2/deficiência , Fenótipo , Fatores de Transcrição SOXE/deficiência , Animais , Células Cultivadas , Humanos , Camundongos , Camundongos Transgênicos , Neurilemoma/metabolismo , Neurilemoma/patologia , Neurofibromatose 2/metabolismo , Neurofibromatose 2/patologia , Neurofibromina 2/genética , Fatores de Transcrição SOXE/fisiologia
16.
EBioMedicine ; 105: 105211, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38917510

RESUMO

BACKGROUND: External radiation therapy (RT) is often a primary treatment for inoperable meningiomas in the absence of established chemotherapy. Histone deacetylase 6 (HDAC6) overexpression, commonly found in cancer, is acknowledged as a driver of cellular growth, and inhibiting HDACs holds promise in improving radiotherapeutic efficacy. Downregulation of HDAC6 facilitates the degradation of ß-catenin. This protein is a key element in the Wnt/ß-catenin signalling pathway, contributing to the progression of meningiomas. METHODS: In order to elucidate the associations and therapeutic potential of HDAC6 inhibitors (HDAC6i) in conjunction with RT, we administered Cay10603, HDAC6i, to both immortalised and patient-derived meningioma cells prior to RT in this study. FINDINGS: Our findings reveal an increase in HDAC6 expression following exposure to RT, which is effectively mitigated with pre-treated Cay10603. The combination of Cay10603 with RT resulted in a synergistic augmentation of cytotoxic effects, as demonstrated through a range of functional assays conducted in both 2D as well as 3D settings; the latter containing syngeneic tumour microenvironment (TME). Radiation-induced DNA damage was augmented by pre-treatment with Cay10603, concomitant with the inhibition of ß-catenin and minichromosome maintenance complex component 2 (MCM2) accumulation within the nucleus. This subsequently inhibited c-myc oncogene expression. INTERPRETATION: Our findings demonstrate the therapeutic potential of Cay10603 to improve the radiosensitisation and provide rationale for combining HDAC6i with RT for the treatment of meningioma. FUNDING: This work was funded by Brain Tumour Research Centre of Excellence award to C Oliver Hanemann.

17.
Artigo em Inglês | MEDLINE | ID: mdl-38465877

RESUMO

Objective: Dyspnea, or breathlessness, is an important symptom in amyotrophic lateral sclerosis/motor neuron disease (ALS/MND). We examined the measurement properties of the Dyspnea-12. Methods: Rasch analysis enabled conversion of raw Dyspnea-12 scores to interval level metric equivalents. Converted data were used to perform trajectory modeling; those following different trajectories were compared for demographic, clinical, symptom, and functioning characteristics. Logistic regression examined differences between distinct trajectories. Results: In 1022 people, at baseline, mean metric Dyspnea-12 was 7.6 (SD 9.3). 49.8% had dyspnea, severe in 12.6%. Trajectory analysis over 28 months revealed three breathlessness trajectories: group 1 reported none at baseline/follow-up (42.7%); group 2 significantly increased over time (9.4%); group 3 had a much higher level at baseline which rose over follow-up (47.9%). Group 3 had worse outcomes on all symptoms, functioning and quality of life; compared to group 1, their odds of: respiratory onset sixfold greater; King's stage ≥3 2.9 greater; increased odds of being bothered by choking, head drop, fasciculations, and muscle cramps; fatigue and anxiety also elevated (p < .01). Conclusion: Dyspnea is a cardinal symptom in ALS/MND and can be quickly measured using the Dyspnea-12. Raw scores can easily be converted to interval level measurement, for valid change scores and trajectory modeling. Dyspnea trajectories reveal different patterns, showing that clinical services must provide monitoring which is customized to individual patient need. Almost half of this large population had worsening dyspnea, confirming the importance of respiratory monitoring and interventions being integrated into routine ALS care.

18.
Neuro Oncol ; 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38695575

RESUMO

Meningiomas are the most common primary intracranial tumors in adults and are increasing in incidence due to the aging population and the rising availability of neuroimaging. While most exhibit non-malignant behaviour, a subset of meningiomas are biologically aggressive and lead to significant neurological morbidity and mortality. In recent years, meaningful advances in our understanding of the biology of these tumors have led to the incorporation of molecular biomarkers into their grading and prognostication. However, unlike other central nervous system tumors, a unified molecular taxonomy for meningiomas has not yet been established and remains an overarching goal of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy-Not Official WHO (cIMPACT-NOW) working group. There also remains clinical equipoise on how specific meningioma cases and patient populations should be optimally managed. To address these existing gaps, members of the International Consortium on Meningiomas (ICOM) including field-leading experts, have prepared a comprehensive consensus narrative review directed towards clinicians, researchers, and patients. Included in this manuscript are detailed overviews of proposed molecular classifications, novel biomarkers, contemporary treatment strategies, trials on systemic therapies, health-related quality of life studies, and management strategies for unique meningioma patient populations. In each section we discuss the current state of knowledge as well as ongoing clinical and research challenges to road map future directions for further investigation.

19.
Am J Med Genet A ; 161A(8): 2027-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23813970

RESUMO

Medulloblastoma is the commonest brain tumor in childhood and in a minority of patients is associated with an underlying genetic disorder such as Gorlin syndrome or familial adenomatous polyposis. Increased susceptibility to certain tumors, including neuroblastoma and some hematological malignancies, is recognized in disorders caused by mutations in genes encoding components of the RAS signaling pathway which include Noonan syndrome, Noonan syndrome with multiple lentigines (NSML; formerly called LEOPARD syndrome), Costello syndrome, Cardiofaciocutaneous syndrome, Legius syndrome, and Neurofibromatosis type 1 (NF1), collectively termed RASopathies. Although an association between medulloblastoma and NF1 has been reported, this tumor has not previously been reported in other RASopathies. We present a patient with NSML caused by the recurrent PTPN11 mutation c.1403C > T (p.Thr468Met) in whom medulloblastoma was diagnosed at age 10 years. Medulloblastoma could therefore be part of the tumor spectrum associated with this disorder.


Assuntos
Síndrome LEOPARD/genética , Meduloblastoma/etiologia , Mutação/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Adulto , DNA/análise , DNA/genética , Humanos , Síndrome LEOPARD/complicações , Masculino , Meduloblastoma/patologia , Pessoa de Meia-Idade , Fenótipo , Reação em Cadeia da Polimerase , Adulto Jovem
20.
Am J Med Genet A ; 161A(3): 405-16, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23401320

RESUMO

Schwannomatosis is the third major form of neurofibromatosis and is characterized by the development of multiple schwannomas in the absence of bilateral vestibular schwannomas. The 2011 Schwannomatosis Update was organized by the Children's Tumor Foundation (www.ctf.org) and held in Los Angeles, CA, from June 5-8, 2011. This article summarizes the highlights presented at the Conference and represents the "state-of-the-field" in 2011. Genetic studies indicate that constitutional mutations in the SMARCB1 tumor suppressor gene occur in 40-50% of familial cases and in 8-10% of sporadic cases of schwannomatosis. Tumorigenesis is thought to occur through a four-hit, three-step model, beginning with a germline mutation in SMARCB1 (hit 1), followed by loss of a portion of chromosome 22 that contains the second SMARCB1 allele and one NF2 allele (hits 2 and 3), followed by mutation of the remaining wild-type NF2 allele (hit 4). Insights from research on HIV and pediatric rhabdoid tumors have shed light on potential molecular pathways that are dysregulated in schwannomatosis-related schwannomas. Mouse models of schwannomatosis have been developed and promise to further expand our understanding of tumorigenesis and the tumor microenvironment. Clinical reports have described the occurrence of intracranial meningiomas in schwannomatosis patients and in families with germline SMARCB1 mutations. The authors propose updated diagnostic criteria to incorporate new clinical and genetic findings since 2005. In the next 5 years, the authors expect that advances in basic research in the pathogenesis of schwannomatosis will lead toward clinical investigations of potential drug therapies.


Assuntos
Neurilemoma/genética , Neurofibromatoses/genética , Neoplasias Cutâneas/genética , Animais , Proteínas Cromossômicas não Histona/fisiologia , Proteínas de Ligação a DNA/fisiologia , Modelos Animais de Doenças , Humanos , Neurilemoma/patologia , Neurilemoma/terapia , Neurofibromatoses/patologia , Neurofibromatoses/terapia , Proteína SMARCB1 , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/terapia , Fatores de Transcrição/fisiologia , Carga Tumoral
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