Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Cell ; 181(6): 1329-1345.e24, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32445698

RESUMO

Posterior fossa A (PFA) ependymomas are lethal malignancies of the hindbrain in infants and toddlers. Lacking highly recurrent somatic mutations, PFA ependymomas are proposed to be epigenetically driven tumors for which model systems are lacking. Here we demonstrate that PFA ependymomas are maintained under hypoxia, associated with restricted availability of specific metabolites to diminish histone methylation, and increase histone demethylation and acetylation at histone 3 lysine 27 (H3K27). PFA ependymomas initiate from a cell lineage in the first trimester of human development that resides in restricted oxygen. Unlike other ependymomas, transient exposure of PFA cells to ambient oxygen induces irreversible cellular toxicity. PFA tumors exhibit a low basal level of H3K27me3, and, paradoxically, inhibition of H3K27 methylation specifically disrupts PFA tumor growth. Targeting metabolism and/or the epigenome presents a unique opportunity for rational therapy for infants with PFA ependymoma.


Assuntos
Ependimoma/genética , Ependimoma/metabolismo , Epigenoma/genética , Neoplasias Infratentoriais/genética , Neoplasias Infratentoriais/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular , Proliferação de Células/genética , Metilação de DNA/genética , Epigenômica/métodos , Histonas/genética , Histonas/metabolismo , Humanos , Lactente , Lisina/genética , Lisina/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Mutação/genética
2.
Cell ; 172(5): 1050-1062.e14, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29474906

RESUMO

While the preponderance of morbidity and mortality in medulloblastoma patients are due to metastatic disease, most research focuses on the primary tumor due to a dearth of metastatic tissue samples and model systems. Medulloblastoma metastases are found almost exclusively on the leptomeningeal surface of the brain and spinal cord; dissemination is therefore thought to occur through shedding of primary tumor cells into the cerebrospinal fluid followed by distal re-implantation on the leptomeninges. We present evidence for medulloblastoma circulating tumor cells (CTCs) in therapy-naive patients and demonstrate in vivo, through flank xenografting and parabiosis, that medulloblastoma CTCs can spread through the blood to the leptomeningeal space to form leptomeningeal metastases. Medulloblastoma leptomeningeal metastases express high levels of the chemokine CCL2, and expression of CCL2 in medulloblastoma in vivo is sufficient to drive leptomeningeal dissemination. Hematogenous dissemination of medulloblastoma offers a new opportunity to diagnose and treat lethal disseminated medulloblastoma.


Assuntos
Meduloblastoma/irrigação sanguínea , Meduloblastoma/patologia , Neoplasias Meníngeas/irrigação sanguínea , Neoplasias Meníngeas/secundário , Aloenxertos , Animais , Linhagem Celular Tumoral , Quimiocina CCL2/metabolismo , Cromossomos Humanos Par 10/genética , Feminino , Humanos , Masculino , Meduloblastoma/genética , Camundongos SCID , Células Neoplásicas Circulantes , Parabiose
4.
Nature ; 572(7767): 67-73, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31043743

RESUMO

Study of the origin and development of cerebellar tumours has been hampered by the complexity and heterogeneity of cerebellar cells that change over the course of development. Here we use single-cell transcriptomics to study more than 60,000 cells from the developing mouse cerebellum and show that different molecular subgroups of childhood cerebellar tumours mirror the transcription of cells from distinct, temporally restricted cerebellar lineages. The Sonic Hedgehog medulloblastoma subgroup transcriptionally mirrors the granule cell hierarchy as expected, while group 3 medulloblastoma resembles Nestin+ stem cells, group 4 medulloblastoma resembles unipolar brush cells, and PFA/PFB ependymoma and cerebellar pilocytic astrocytoma resemble the prenatal gliogenic progenitor cells. Furthermore, single-cell transcriptomics of human childhood cerebellar tumours demonstrates that many bulk tumours contain a mixed population of cells with divergent differentiation. Our data highlight cerebellar tumours as a disorder of early brain development and provide a proximate explanation for the peak incidence of cerebellar tumours in early childhood.


Assuntos
Neoplasias Cerebelares/genética , Neoplasias Cerebelares/patologia , Evolução Molecular , Feto/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação Neoplásica da Expressão Gênica , Transcrição Gênica , Animais , Neoplasias Cerebelares/classificação , Cerebelo/citologia , Cerebelo/embriologia , Cerebelo/metabolismo , Criança , Feminino , Feto/citologia , Glioma/classificação , Glioma/genética , Glioma/patologia , Humanos , Meduloblastoma/classificação , Meduloblastoma/genética , Meduloblastoma/patologia , Camundongos , Análise de Sequência de RNA , Análise de Célula Única , Fatores de Tempo , Transcriptoma/genética
5.
Nature ; 529(7586): 351-7, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26760213

RESUMO

The development of targeted anti-cancer therapies through the study of cancer genomes is intended to increase survival rates and decrease treatment-related toxicity. We treated a transposon-driven, functional genomic mouse model of medulloblastoma with 'humanized' in vivo therapy (microneurosurgical tumour resection followed by multi-fractionated, image-guided radiotherapy). Genetic events in recurrent murine medulloblastoma exhibit a very poor overlap with those in matched murine diagnostic samples (<5%). Whole-genome sequencing of 33 pairs of human diagnostic and post-therapy medulloblastomas demonstrated substantial genetic divergence of the dominant clone after therapy (<12% diagnostic events were retained at recurrence). In both mice and humans, the dominant clone at recurrence arose through clonal selection of a pre-existing minor clone present at diagnosis. Targeted therapy is unlikely to be effective in the absence of the target, therefore our results offer a simple, proximal, and remediable explanation for the failure of prior clinical trials of targeted therapy.


Assuntos
Neoplasias Cerebelares/terapia , Células Clonais/efeitos dos fármacos , Células Clonais/metabolismo , Meduloblastoma/terapia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Seleção Genética/efeitos dos fármacos , Animais , Neoplasias Cerebelares/genética , Neoplasias Cerebelares/patologia , Neoplasias Cerebelares/radioterapia , Neoplasias Cerebelares/cirurgia , Células Clonais/patologia , Radiação Cranioespinal , Análise Mutacional de DNA , Modelos Animais de Doenças , Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Feminino , Genoma Humano/genética , Humanos , Masculino , Meduloblastoma/genética , Meduloblastoma/patologia , Meduloblastoma/radioterapia , Meduloblastoma/cirurgia , Camundongos , Terapia de Alvo Molecular/métodos , Recidiva Local de Neoplasia/terapia , Radioterapia Guiada por Imagem , Transdução de Sinais , Ensaios Antitumorais Modelo de Xenoenxerto
6.
STAR Protoc ; 5(2): 103078, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38781075

RESUMO

Here, we present a protocol for preclinical evaluation of locoregionally delivered CAR T cells in patient-derived xenograft models of primary, metastatic, and recurrent brain tumors. We provide instructions for isolating peripheral blood mononuclear cells (PBMCs), producing CAR T cells in conjunction with locoregional delivery, and preclinical trial design and analysis involving CAR T cells. Additionally, we describe comprehensive preclinical readouts and guidelines for critical endpoint sample collections. In line with clinical trial procedures, our protocol broadens available treatment modalities for direct clinical translation. For complete details on the use and execution of this protocol, please refer to Donovan et al.1.


Assuntos
Neoplasias Encefálicas , Imunoterapia Adotiva , Ensaios Antitumorais Modelo de Xenoenxerto , Humanos , Neoplasias Encefálicas/terapia , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Animais , Camundongos , Imunoterapia Adotiva/métodos , Linfócitos T/imunologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/imunologia , Receptores de Antígenos Quiméricos/imunologia
7.
Nat Commun ; 15(1): 270, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38191555

RESUMO

Many genes that drive normal cellular development also contribute to oncogenesis. Medulloblastoma (MB) tumors likely arise from neuronal progenitors in the cerebellum, and we hypothesized that the heterogeneity observed in MBs with sonic hedgehog (SHH) activation could be due to differences in developmental pathways. To investigate this question, here we perform single-nucleus RNA sequencing on highly differentiated SHH MBs with extensively nodular histology and observed malignant cells resembling each stage of canonical granule neuron development. Through innovative computational approaches, we connect these results to published datasets and find that some established molecular subtypes of SHH MB appear arrested at different developmental stages. Additionally, using multiplexed proteomic imaging and MALDI imaging mass spectrometry, we identify distinct histological and metabolic profiles for highly differentiated tumors. Our approaches are applicable to understanding the interplay between heterogeneity and differentiation in other cancers and can provide important insights for the design of targeted therapies.


Assuntos
Neoplasias Cerebelares , Meduloblastoma , Humanos , Proteínas Hedgehog/genética , Meduloblastoma/genética , Proteômica , Cerebelo , Neoplasias Cerebelares/genética
8.
Cancer Discov ; 14(4): 663-668, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38571421

RESUMO

SUMMARY: We are building the world's first Virtual Child-a computer model of normal and cancerous human development at the level of each individual cell. The Virtual Child will "develop cancer" that we will subject to unlimited virtual clinical trials that pinpoint, predict, and prioritize potential new treatments, bringing forward the day when no child dies of cancer, giving each one the opportunity to lead a full and healthy life.


Assuntos
Neoplasias , Humanos , Neoplasias/genética
9.
Neuron ; 111(1): 30-48.e14, 2023 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-36323321

RESUMO

Major obstacles in brain cancer treatment include the blood-tumor barrier (BTB), which limits the access of most therapeutic agents, and quiescent tumor cells, which resist conventional chemotherapy. Here, we show that Sox2+ tumor cells project cellular processes to ensheathe capillaries in mouse medulloblastoma (MB), a process that depends on the mechanosensitive ion channel Piezo2. MB develops a tissue stiffness gradient as a function of distance to capillaries. Sox2+ tumor cells perceive substrate stiffness to sustain local intracellular calcium, actomyosin tension, and adhesion to promote cellular process growth and cell surface sequestration of ß-catenin. Piezo2 knockout reverses WNT/ß-catenin signaling states between Sox2+ tumor cells and endothelial cells, compromises the BTB, reduces the quiescence of Sox2+ tumor cells, and markedly enhances the MB response to chemotherapy. Our study reveals that mechanosensitive tumor cells construct the BTB to mask tumor chemosensitivity. Targeting Piezo2 addresses the BTB and tumor quiescence properties that underlie treatment failures in brain cancer.


Assuntos
Neoplasias Encefálicas , beta Catenina , Camundongos , Animais , beta Catenina/metabolismo , beta Catenina/uso terapêutico , Células Endoteliais/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Encéfalo/metabolismo , Canais Iônicos/metabolismo , Barreira Hematoencefálica/metabolismo
10.
Nat Med ; 26(5): 720-731, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32341580

RESUMO

Recurrent medulloblastoma and ependymoma are universally lethal, with no approved targeted therapies and few candidates presently under clinical evaluation. Nearly all recurrent medulloblastomas and posterior fossa group A (PFA) ependymomas are located adjacent to and bathed by the cerebrospinal fluid, presenting an opportunity for locoregional therapy, bypassing the blood-brain barrier. We identify three cell-surface targets, EPHA2, HER2 and interleukin 13 receptor α2, expressed on medulloblastomas and ependymomas, but not expressed in the normal developing brain. We validate intrathecal delivery of EPHA2, HER2 and interleukin 13 receptor α2 chimeric antigen receptor T cells as an effective treatment for primary, metastatic and recurrent group 3 medulloblastoma and PFA ependymoma xenografts in mouse models. Finally, we demonstrate that administration of these chimeric antigen receptor T cells into the cerebrospinal fluid, alone or in combination with azacytidine, is a highly effective therapy for multiple metastatic mouse models of group 3 medulloblastoma and PFA ependymoma, thereby providing a rationale for clinical trials of these approaches in humans.


Assuntos
Neoplasias Encefálicas/terapia , Vacinas Anticâncer/administração & dosagem , Líquido Cefalorraquidiano/efeitos dos fármacos , Ependimoma/terapia , Imunoterapia Adotiva/métodos , Meduloblastoma/terapia , Animais , Neoplasias Encefálicas/líquido cefalorraquidiano , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Neoplasias Cerebelares/líquido cefalorraquidiano , Neoplasias Cerebelares/imunologia , Neoplasias Cerebelares/patologia , Neoplasias Cerebelares/terapia , Líquido Cefalorraquidiano/imunologia , Criança , Pré-Escolar , Sistemas de Liberação de Medicamentos/métodos , Ependimoma/líquido cefalorraquidiano , Ependimoma/imunologia , Ependimoma/patologia , Feminino , Células HEK293 , Humanos , Lactente , Injeções Intraventriculares , Masculino , Meduloblastoma/líquido cefalorraquidiano , Meduloblastoma/imunologia , Meduloblastoma/patologia , Camundongos , Metástase Neoplásica , Receptores de Antígenos Quiméricos/administração & dosagem , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/transplante , Resultado do Tratamento , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Nat Genet ; 51(12): 1702-1713, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31768071

RESUMO

Childhood brain tumors have suspected prenatal origins. To identify vulnerable developmental states, we generated a single-cell transcriptome atlas of >65,000 cells from embryonal pons and forebrain, two major tumor locations. We derived signatures for 191 distinct cell populations and defined the regional cellular diversity and differentiation dynamics. Projection of bulk tumor transcriptomes onto this dataset shows that WNT medulloblastomas match the rhombic lip-derived mossy fiber neuronal lineage and embryonal tumors with multilayered rosettes fully recapitulate a neuronal lineage, while group 2a/b atypical teratoid/rhabdoid tumors may originate outside the neuroectoderm. Importantly, single-cell tumor profiles reveal highly defined cell hierarchies that mirror transcriptional programs of the corresponding normal lineages. Our findings identify impaired differentiation of specific neural progenitors as a common mechanism underlying these pediatric cancers and provide a rational framework for future modeling and therapeutic interventions.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Encéfalo/embriologia , Regulação da Expressão Gênica no Desenvolvimento , Animais , Encéfalo/patologia , Linhagem Celular Tumoral , Humanos , Lactente , Meduloblastoma/genética , Meduloblastoma/patologia , Camundongos , Neoplasias Embrionárias de Células Germinativas/genética , Neoplasias Embrionárias de Células Germinativas/patologia , Fibras Nervosas/patologia , Fibras Nervosas/fisiologia , Prosencéfalo/citologia , Prosencéfalo/embriologia , Tumor Rabdoide/genética , Tumor Rabdoide/patologia , Análise de Célula Única
13.
Nat Genet ; 49(5): 780-788, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28394352

RESUMO

Spatial heterogeneity of transcriptional and genetic markers between physically isolated biopsies of a single tumor poses major barriers to the identification of biomarkers and the development of targeted therapies that will be effective against the entire tumor. We analyzed the spatial heterogeneity of multiregional biopsies from 35 patients, using a combination of transcriptomic and genomic profiles. Medulloblastomas (MBs), but not high-grade gliomas (HGGs), demonstrated spatially homogeneous transcriptomes, which allowed for accurate subgrouping of tumors from a single biopsy. Conversely, somatic mutations that affect genes suitable for targeted therapeutics demonstrated high levels of spatial heterogeneity in MB, malignant glioma, and renal cell carcinoma (RCC). Actionable targets found in a single MB biopsy were seldom clonal across the entire tumor, which brings the efficacy of monotherapies against a single target into question. Clinical trials of targeted therapies for MB should first ensure the spatially ubiquitous nature of the target mutation.


Assuntos
Neoplasias Cerebelares/genética , Regulação Neoplásica da Expressão Gênica , Meduloblastoma/genética , Transcriptoma , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Cerebelares/patologia , Criança , Pré-Escolar , Análise por Conglomerados , Variações do Número de Cópias de DNA , Feminino , Perfilação da Expressão Gênica/métodos , Heterogeneidade Genética , Estudo de Associação Genômica Ampla , Humanos , Mutação INDEL , Masculino , Meduloblastoma/patologia , Pessoa de Meia-Idade , Mutação , Polimorfismo de Nucleotídeo Único , Análise de Componente Principal , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
Anticancer Res ; 34(12): 6919-24, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25503117

RESUMO

BACKGROUND/AIM: While neuron-glia 2 (NG2) is well-characterized in the developing brain and in adult high-grade gliomas, little is known about NG2 expression in paediatric brain tumors. Here, NG2 expression was examined in a range of paediatric brain tumors. MATERIALS AND METHODS: A retrospective immunohistopathological analysis of 57 paediatric brain tumor biopsies of various tumor types was carried out. Paediatric cell lines, including two medulloblastomas and one dysembryoplastic neuroepithelial tumor, in addition to one adult high-grade glioma, were also assessed for NG2 expression. RESULTS: NG2-positive staining was seen in all dysembryoplastic neuroepithelial tumors (DNETs) examined; however, only two of the fourteen medulloblastomas examined were NG2-positive. Compared to adult glioma, there was a lack of NG2 staining in the vasculature of paediatric brain tumors. CONCLUSION: NG2 expression in paediatric brain tumors differs depending upon type and, unlike adult glioma, includes expression on lower-grade tumors.


Assuntos
Antígenos/metabolismo , Neoplasias Encefálicas/metabolismo , Proteoglicanas/metabolismo , Adolescente , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Gradação de Tumores , Estudos Retrospectivos
16.
Int J Oncol ; 42(3): 1011-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23340741

RESUMO

The cancer stem cell (CSC) marker CD133 is widely expressed in gliomas and employed mostly by use of the CD133/1 antibody which binds the extracellular glycosylated AC133 epitope. CD133 recognition may, however, be affected by its glycosylation pattern and oxygen tension. The present study investigates the effect of oxygen deprivation on CD133 expression and glycosylation status employing a high AC133-expressing glioblastoma multiforme (GBM) cell line, IN699. IN699 cells were cultured under normoxic (21% O2) and hypoxic (3% O2) conditions. CD133 expression was analysed by western blotting (WB), qRT-PCR, immunocytochemistry (ICC) and flow cytometry using the glycosylation-specific antibody CD133/1 and ab19898 which binds the unglycosylated intra-cellular residues of CD133. By flow cytometry, ab19898 detected 94.1% and 96.2% CD133+ cells under normoxia and hypoxia, respectively. Hypoxia significantly increased the percentage of CD133+ cells from 69% to 92% using CD133/1 (p<0.005). Moreover, a significantly higher geomean fluorescence intensity (GMI) was demonstrated by ab19898 (p<0.005) in CD133+ cells. WB and qRT-PCR results were consistent with flow cytometry data. Furthermore, over a period of 72-h incubation under normoxic and hypoxic conditions after autoMACS sorting, an average of 31.8% and 42.2%, respectively, of CD133-negative IN699 cells became positive using CD133/1. Our data show that a) previously reported CD133- cells may have been misidentified using the glycosylation-specific CD133/1 as constitutive expression of CD133 was detected by the intracellular antibody ab19898; b) hypoxia promotes glycosylation status of CD133, indicating possible involvement of glycosylated CD133 in the process of anti-hypoxia-mediated apoptosis.


Assuntos
Antígenos CD/metabolismo , Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , Glicoproteínas/metabolismo , Células-Tronco Neoplásicas/metabolismo , Peptídeos/metabolismo , Antígeno AC133 , Anticorpos Monoclonais/imunologia , Antígenos CD/imunologia , Apoptose , Hipóxia Celular , Linhagem Celular Tumoral , Glicoproteínas/imunologia , Glicosilação , Humanos , Peptídeos/imunologia
17.
Transl Oncol ; 5(3): 141-54, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22741033

RESUMO

Few studies on the biologic and molecular properties of pediatric glioblastoma have been performed. Until now, differential genomic analysis of CD133(+)ve and CD133(-)ve fractions has not been described in pediatric glioma. We hypothesize not only that the presence of CD133 could be the source of tumor resistance but also that maintenance of this molecule by hypoxia dictates cellular and molecular behavior. From a series of human glioblastoma biopsies investigated, only one, IN699 (from a pediatric glioblastoma), generated greater than 4% of the total cell volume as CD133(+)ve cells. Using this pediatric glioblastoma, containing unprecedented high levels of the putative brain tumor stem cell marker CD133, as a study model, we report biologic and molecular characteristics of the parent culture and of CD133(+)ve and CD133(-)ve populations derived therefrom under atmospheric and hypoxic culture conditions. Immunocytochemistry and flow cytometry were performed with antigenic markers known to characterize neural stem cells and associated glioma behavior. Behavioral analysis was carried out using proliferation, adhesion, migration, and invasion assays. Cell cycle analysis and array comparative genomic hybridization were used to assess copy number profiles for parental cells and CD133(+)ve and CD133(-)ve fractions, respectively. With regard to invasion and proliferation, CD133(+)ve and CD133(-)ve fractions were inversely proportional, with a significant increase in invasive propensity within the CD133(-)ve cells (P < .005) and a significant increase in proliferation within CD133(+)ve cells (P < .005). Our observations indicate identical genomic imbalances between CD133(+)ve and CD133(-)ve fractions. Furthermore, our research documents a direct link between decreasing oxygen tension and CD133 expression.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA