RESUMEN
We identify a population of Protogenin-positive (PRTG+ve) MYChigh NESTINlow stem cells in the four-week-old human embryonic hindbrain that subsequently localizes to the ventricular zone of the rhombic lip (RLVZ). Oncogenic transformation of early Prtg+ve rhombic lip stem cells initiates group 3 medulloblastoma (Gr3-MB)-like tumors. PRTG+ve stem cells grow adjacent to a human-specific interposed vascular plexus in the RLVZ, a phenotype that is recapitulated in Gr3-MB but not in other types of medulloblastoma. Co-culture of Gr3-MB with endothelial cells promotes tumor stem cell growth, with the endothelial cells adopting an immature phenotype. Targeting the PRTGhigh compartment of Gr3-MB in vivo using either the diphtheria toxin system or chimeric antigen receptor T cells constitutes effective therapy. Human Gr3-MBs likely arise from early embryonic RLVZ PRTG+ve stem cells inhabiting a specific perivascular niche. Targeting the PRTGhigh compartment and/or the perivascular niche represents an approach to treat children with Gr3-MB.
RESUMEN
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.
Asunto(s)
Ependimoma/genética , Ependimoma/metabolismo , Epigenoma/genética , Neoplasias Infratentoriales/genética , Neoplasias Infratentoriales/metabolismo , Animales , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Línea Celular , Proliferación Celular/genética , Metilación de ADN/genética , Epigenómica/métodos , Histonas/genética , Histonas/metabolismo , Humanos , Lactante , Lisina/genética , Lisina/metabolismo , Masculino , Ratones Endogámicos C57BL , Mutación/genéticaRESUMEN
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.
Asunto(s)
Meduloblastoma/irrigación sanguínea , Meduloblastoma/patología , Neoplasias Meníngeas/irrigación sanguínea , Neoplasias Meníngeas/secundario , Aloinjertos , Animales , Línea Celular Tumoral , Quimiocina CCL2/metabolismo , Cromosomas Humanos Par 10/genética , Femenino , Humanos , Masculino , Meduloblastoma/genética , Ratones SCID , Células Neoplásicas Circulantes , ParabiosisRESUMEN
Metabolic adaptation is essential for cell survival during nutrient deprivation. We report that eukaryotic elongation factor 2 kinase (eEF2K), which is activated by AMP-kinase (AMPK), confers cell survival under acute nutrient depletion by blocking translation elongation. Tumor cells exploit this pathway to adapt to nutrient deprivation by reactivating the AMPK-eEF2K axis. Adaptation of transformed cells to nutrient withdrawal is severely compromised in cells lacking eEF2K. Moreover, eEF2K knockdown restored sensitivity to acute nutrient deprivation in highly resistant human tumor cell lines. In vivo, overexpression of eEF2K rendered murine tumors remarkably resistant to caloric restriction. Expression of eEF2K strongly correlated with overall survival in human medulloblastoma and glioblastoma multiforme. Finally, C. elegans strains deficient in efk-1, the eEF2K ortholog, were severely compromised in their response to nutrient depletion. Our data highlight a conserved role for eEF2K in protecting cells from nutrient deprivation and in conferring tumor cell adaptation to metabolic stress. PAPERCLIP:
Asunto(s)
Caenorhabditis elegans/metabolismo , Quinasa del Factor 2 de Elongación/metabolismo , Neoplasias/fisiopatología , Extensión de la Cadena Peptídica de Translación , Transducción de Señal , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Neoplasias Encefálicas/fisiopatología , Caenorhabditis elegans/genética , Supervivencia Celular , Transformación Celular Neoplásica , Quinasa del Factor 2 de Elongación/genética , Privación de Alimentos , Glioblastoma/fisiopatología , Células HeLa , Humanos , Ratones , Ratones Desnudos , Células 3T3 NIH , Trasplante de Neoplasias , Factor 2 de Elongación Peptídica/metabolismo , Trasplante HeterólogoRESUMEN
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.
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Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/patología , Evolución Molecular , Feto/metabolismo , Regulación del Desarrollo de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Transcripción Genética , Animales , Neoplasias Cerebelosas/clasificación , Cerebelo/citología , Cerebelo/embriología , Cerebelo/metabolismo , Niño , Femenino , Feto/citología , Glioma/clasificación , Glioma/genética , Glioma/patología , Humanos , Meduloblastoma/clasificación , Meduloblastoma/genética , Meduloblastoma/patología , Ratones , Análisis de Secuencia de ARN , Análisis de la Célula Individual , Factores de Tiempo , Transcriptoma/genéticaRESUMEN
In cancer, recurrent somatic single-nucleotide variants-which are rare in most paediatric cancers-are confined largely to protein-coding genes1-3. Here we report highly recurrent hotspot mutations (r.3A>G) of U1 spliceosomal small nuclear RNAs (snRNAs) in about 50% of Sonic hedgehog (SHH) medulloblastomas. These mutations were not present across other subgroups of medulloblastoma, and we identified these hotspot mutations in U1 snRNA in only <0.1% of 2,442 cancers, across 36 other tumour types. The mutations occur in 97% of adults (subtype SHHδ) and 25% of adolescents (subtype SHHα) with SHH medulloblastoma, but are largely absent from SHH medulloblastoma in infants. The U1 snRNA mutations occur in the 5' splice-site binding region, and snRNA-mutant tumours have significantly disrupted RNA splicing and an excess of 5' cryptic splicing events. Alternative splicing mediated by mutant U1 snRNA inactivates tumour-suppressor genes (PTCH1) and activates oncogenes (GLI2 and CCND2), and represents a target for therapy. These U1 snRNA mutations provide an example of highly recurrent and tissue-specific mutations of a non-protein-coding gene in cancer.
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Neoplasias Cerebelosas/genética , Proteínas Hedgehog/genética , Meduloblastoma/genética , ARN Nuclear Pequeño/genética , Adolescente , Adulto , Empalme Alternativo , Proteínas Hedgehog/metabolismo , Humanos , Mutación , Sitios de Empalme de ARN , Empalme del ARNRESUMEN
Genomic sequencing has driven precision-based oncology therapy; however, the genetic drivers of many malignancies remain unknown or non-targetable, so alternative approaches to the identification of therapeutic leads are necessary. Ependymomas are chemotherapy-resistant brain tumours, which, despite genomic sequencing, lack effective molecular targets. Intracranial ependymomas are segregated on the basis of anatomical location (supratentorial region or posterior fossa) and further divided into distinct molecular subgroups that reflect differences in the age of onset, gender predominance and response to therapy. The most common and aggressive subgroup, posterior fossa ependymoma group A (PF-EPN-A), occurs in young children and appears to lack recurrent somatic mutations. Conversely, posterior fossa ependymoma group B (PF-EPN-B) tumours display frequent large-scale copy number gains and losses but have favourable clinical outcomes. More than 70% of supratentorial ependymomas are defined by highly recurrent gene fusions in the NF-κB subunit gene RELA (ST-EPN-RELA), and a smaller number involve fusion of the gene encoding the transcriptional activator YAP1 (ST-EPN-YAP1). Subependymomas, a distinct histologic variant, can also be found within the supratetorial and posterior fossa compartments, and account for the majority of tumours in the molecular subgroups ST-EPN-SE and PF-EPN-SE. Here we describe mapping of active chromatin landscapes in 42 primary ependymomas in two non-overlapping primary ependymoma cohorts, with the goal of identifying essential super-enhancer-associated genes on which tumour cells depend. Enhancer regions revealed putative oncogenes, molecular targets and pathways; inhibition of these targets with small molecule inhibitors or short hairpin RNA diminished the proliferation of patient-derived neurospheres and increased survival in mouse models of ependymomas. Through profiling of transcriptional enhancers, our study provides a framework for target and drug discovery in other cancers that lack known genetic drivers and are therefore difficult to treat.
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Elementos de Facilitación Genéticos/genética , Ependimoma/tratamiento farmacológico , Ependimoma/genética , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes/genética , Terapia Molecular Dirigida , Oncogenes/genética , Factores de Transcripción/metabolismo , Animales , Secuencia de Bases , Ependimoma/clasificación , Ependimoma/patología , Femenino , Humanos , Ratones , Medicina de Precisión , Interferencia de ARN , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Current therapies for medulloblastoma, a highly malignant childhood brain tumour, impose debilitating effects on the developing child, and highlight the need for molecularly targeted treatments with reduced toxicity. Previous studies have been unable to identify the full spectrum of driver genes and molecular processes that operate in medulloblastoma subgroups. Here we analyse the somatic landscape across 491 sequenced medulloblastoma samples and the molecular heterogeneity among 1,256 epigenetically analysed cases, and identify subgroup-specific driver alterations that include previously undiscovered actionable targets. Driver mutations were confidently assigned to most patients belonging to Group 3 and Group 4 medulloblastoma subgroups, greatly enhancing previous knowledge. New molecular subtypes were differentially enriched for specific driver events, including hotspot in-frame insertions that target KBTBD4 and 'enhancer hijacking' events that activate PRDM6. Thus, the application of integrative genomics to an extensive cohort of clinical samples derived from a single childhood cancer entity revealed a series of cancer genes and biologically relevant subtype diversity that represent attractive therapeutic targets for the treatment of patients with medulloblastoma.
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Análisis Mutacional de ADN , Genoma Humano/genética , Meduloblastoma/clasificación , Meduloblastoma/genética , Secuenciación Completa del Genoma , Carcinogénesis/genética , Proteínas Portadoras/genética , Estudios de Cohortes , Metilación de ADN , Conjuntos de Datos como Asunto , Epistasis Genética , Genómica , Humanos , Terapia Molecular Dirigida , Proteínas Musculares/genética , Mutación , Oncogenes/genética , Factores de Transcripción/genética , Proteínas Wnt/genéticaRESUMEN
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.
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Neoplasias Cerebelosas/terapia , Células Clonales/efectos de los fármacos , Células Clonales/metabolismo , Meduloblastoma/terapia , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Selección Genética/efectos de los fármacos , Animales , Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/patología , Neoplasias Cerebelosas/radioterapia , Neoplasias Cerebelosas/cirugía , Células Clonales/patología , Irradiación Craneoespinal , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Drosophila melanogaster/citología , Drosophila melanogaster/genética , Femenino , Genoma Humano/genética , Humanos , Masculino , Meduloblastoma/genética , Meduloblastoma/patología , Meduloblastoma/radioterapia , Meduloblastoma/cirugía , Ratones , Terapia Molecular Dirigida/métodos , Recurrencia Local de Neoplasia/terapia , Radioterapia Guiada por Imagen , Transducción de Señal , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Medulloblastoma, the most common malignant paediatric brain tumour, arises in the cerebellum and disseminates through the cerebrospinal fluid in the leptomeningeal space to coat the brain and spinal cord. Dissemination, a marker of poor prognosis, is found in up to 40% of children at diagnosis and in most children at the time of recurrence. Affected children therefore are treated with radiation to the entire developing brain and spinal cord, followed by high-dose chemotherapy, with the ensuing deleterious effects on the developing nervous system. The mechanisms of dissemination through the cerebrospinal fluid are poorly studied, and medulloblastoma metastases have been assumed to be biologically similar to the primary tumour. Here we show that in both mouse and human medulloblastoma, the metastases from an individual are extremely similar to each other but are divergent from the matched primary tumour. Clonal genetic events in the metastases can be demonstrated in a restricted subclone of the primary tumour, suggesting that only rare cells within the primary tumour have the ability to metastasize. Failure to account for the bicompartmental nature of metastatic medulloblastoma could be a major barrier to the development of effective targeted therapies.
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Evolución Clonal/genética , Meduloblastoma/genética , Meduloblastoma/patología , Metástasis de la Neoplasia/genética , Metástasis de la Neoplasia/patología , Animales , Islas de CpG/genética , Metilación de ADN , Elementos Transponibles de ADN/genética , Modelos Animales de Enfermedad , Genes p53/genética , Mutación de Línea Germinal/genética , Humanos , Síndrome de Li-Fraumeni/complicaciones , Síndrome de Li-Fraumeni/genética , Meduloblastoma/complicaciones , Ratones , Mutagénesis Insercional , Tasa de SupervivenciaRESUMEN
Medulloblastoma, the most common malignant paediatric brain tumour, is currently treated with nonspecific cytotoxic therapies including surgery, whole-brain radiation, and aggressive chemotherapy. As medulloblastoma exhibits marked intertumoural heterogeneity, with at least four distinct molecular variants, previous attempts to identify targets for therapy have been underpowered because of small samples sizes. Here we report somatic copy number aberrations (SCNAs) in 1,087 unique medulloblastomas. SCNAs are common in medulloblastoma, and are predominantly subgroup-enriched. The most common region of focal copy number gain is a tandem duplication of SNCAIP, a gene associated with Parkinson's disease, which is exquisitely restricted to Group 4α. Recurrent translocations of PVT1, including PVT1-MYC and PVT1-NDRG1, that arise through chromothripsis are restricted to Group 3. Numerous targetable SCNAs, including recurrent events targeting TGF-ß signalling in Group 3, and NF-κB signalling in Group 4, suggest future avenues for rational, targeted therapy.
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Neoplasias Cerebelosas/clasificación , Neoplasias Cerebelosas/genética , Genoma Humano/genética , Variación Estructural del Genoma/genética , Meduloblastoma/clasificación , Meduloblastoma/genética , Proteínas Portadoras/genética , Neoplasias Cerebelosas/metabolismo , Niño , Variaciones en el Número de Copia de ADN/genética , Duplicación de Gen/genética , Genes myc/genética , Genómica , Proteínas Hedgehog/metabolismo , Humanos , Meduloblastoma/metabolismo , FN-kappa B/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas de Fusión Oncogénica/genética , Proteínas/genética , ARN Largo no Codificante , Transducción de Señal , Factor de Crecimiento Transformador beta/metabolismo , Translocación Genética/genéticaRESUMEN
Medulloblastoma comprises four distinct molecular variants with distinct genetics, transcriptomes, and outcomes. Subgroup affiliation has been previously shown to remain stable at the time of recurrence, which likely reflects their distinct cells of origin. However, a therapeutically relevant question that remains unanswered is subgroup stability in the metastatic compartment. We assembled a cohort of 12-paired primary-metastatic tumors collected in the MAGIC consortium, and established their molecular subgroup affiliation by performing integrative gene expression and DNA methylation analysis. Frozen tissues were collected and profiled using Affymetrix gene expression arrays and Illumina methylation arrays. Class prediction and hierarchical clustering were performed using existing published datasets. Our molecular analysis, using consensus integrative genomic data, establishes the unequivocal maintenance of molecular subgroup affiliation in metastatic medulloblastoma. We further validated these findings by interrogating a non-overlapping cohort of 19 pairs of primary-metastatic tumors from the Burdenko Neurosurgical Institute using an orthogonal technique of immunohistochemical staining. This investigation represents the largest reported primary-metastatic paired cohort profiled to date and provides a unique opportunity to evaluate subgroup-specific molecular aberrations within the metastatic compartment. Our findings further support the hypothesis that medulloblastoma subgroups arise from distinct cells of origin, which are carried forward from ontogeny to oncology.
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Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/patología , Meduloblastoma/genética , Meduloblastoma/patología , Metástasis de la Neoplasia/genética , Adolescente , Niño , Preescolar , Análisis por Conglomerados , Femenino , Humanos , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , TranscriptomaRESUMEN
Telomerase reverse transcriptase (TERT) promoter mutations were recently shown to drive telomerase activity in various cancer types, including medulloblastoma. However, the clinical and biological implications of TERT mutations in medulloblastoma have not been described. Hence, we sought to describe these mutations and their impact in a subgroup-specific manner. We analyzed the TERT promoter by direct sequencing and genotyping in 466 medulloblastomas. The mutational distributions were determined according to subgroup affiliation, demographics, and clinical, prognostic, and molecular features. Integrated genomics approaches were used to identify specific somatic copy number alterations in TERT promoter-mutated and wild-type tumors. Overall, TERT promoter mutations were identified in 21 % of medulloblastomas. Strikingly, the highest frequencies of TERT mutations were observed in SHH (83 %; 55/66) and WNT (31 %; 4/13) medulloblastomas derived from adult patients. Group 3 and Group 4 harbored this alteration in <5 % of cases and showed no association with increased patient age. The prognostic implications of these mutations were highly subgroup-specific. TERT mutations identified a subset with good and poor prognosis in SHH and Group 4 tumors, respectively. Monosomy 6 was mostly restricted to WNT tumors without TERT mutations. Hallmark SHH focal copy number aberrations and chromosome 10q deletion were mutually exclusive with TERT mutations within SHH tumors. TERT promoter mutations are the most common recurrent somatic point mutation in medulloblastoma, and are very highly enriched in adult SHH and WNT tumors. TERT mutations define a subset of SHH medulloblastoma with distinct demographics, cytogenetics, and outcomes.
Asunto(s)
Neoplasias Encefálicas/genética , Meduloblastoma/genética , Mutación , Regiones Promotoras Genéticas , Telomerasa/genética , Adolescente , Adulto , Neoplasias Encefálicas/patología , Niño , Preescolar , Análisis Mutacional de ADN , Femenino , Perfilación de la Expresión Génica , Genotipo , Humanos , Lactante , Masculino , Meduloblastoma/patología , Persona de Mediana Edad , PronósticoRESUMEN
Medulloblastoma is the most common malignant pediatric brain tumor. Despite its prevalence and importance in pediatric neuro-oncology, the genes and pathways responsible for its initiation, maintenance, and progression remain poorly understood. Genetically engineered mouse models are an essential tool for uncovering the molecular and cellular basis of human diseases, including cancer, and serve a valuable role as preclinical models for testing targeted therapies. In this review, we summarize how such models have been successfully applied to the study of medulloblastoma over the past decade and what we might expect in the coming years.
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Neoplasias Cerebelosas , Modelos Animales de Enfermedad , Ingeniería Genética , Proteínas Hedgehog/metabolismo , Meduloblastoma , Animales , Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/metabolismo , Neoplasias Cerebelosas/patología , Humanos , Meduloblastoma/genética , Meduloblastoma/metabolismo , Meduloblastoma/patología , Ratones , Ratones Transgénicos , Mutación , Receptores Patched , Interferencia de ARN , ARN Interferente Pequeño/genética , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Receptor Smoothened , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Sonic hedgehog medulloblastoma encompasses a clinically and molecularly diverse group of cancers of the developing central nervous system. Here, we use unbiased sequencing of the transcriptome across a large cohort of 250 tumors to reveal differences among molecular subtypes of the disease, and demonstrate the previously unappreciated importance of non-coding RNA transcripts. We identify alterations within the cAMP dependent pathway (GNAS, PRKAR1A) which converge on GLI2 activity and show that 18% of tumors have a genetic event that directly targets the abundance and/or stability of MYCN. Furthermore, we discover an extensive network of fusions in focally amplified regions encompassing GLI2, and several loss-of-function fusions in tumor suppressor genes PTCH1, SUFU and NCOR1. Molecular convergence on a subset of genes by nucleotide variants, copy number aberrations, and gene fusions highlight the key roles of specific pathways in the pathogenesis of Sonic hedgehog medulloblastoma and open up opportunities for therapeutic intervention.
Asunto(s)
Neoplasias Cerebelosas/genética , Regulación Neoplásica de la Expresión Génica , Proteínas Hedgehog/genética , Meduloblastoma/genética , Transcriptoma , Adolescente , Adulto , Niño , Preescolar , Femenino , Redes Reguladoras de Genes , Variación Genética , Humanos , Lactante , Masculino , Persona de Mediana Edad , Transducción de Señal/genética , Adulto JovenRESUMEN
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.
Asunto(s)
Neoplasias Encefálicas/terapia , Vacunas contra el Cáncer/administración & dosificación , Líquido Cefalorraquídeo/efectos de los fármacos , Ependimoma/terapia , Inmunoterapia Adoptiva/métodos , Meduloblastoma/terapia , Animales , Neoplasias Encefálicas/líquido cefalorraquídeo , Neoplasias Encefálicas/inmunología , Neoplasias Encefálicas/patología , Neoplasias Cerebelosas/líquido cefalorraquídeo , Neoplasias Cerebelosas/inmunología , Neoplasias Cerebelosas/patología , Neoplasias Cerebelosas/terapia , Líquido Cefalorraquídeo/inmunología , Niño , Preescolar , Sistemas de Liberación de Medicamentos/métodos , Ependimoma/líquido cefalorraquídeo , Ependimoma/inmunología , Ependimoma/patología , Femenino , Células HEK293 , Humanos , Lactante , Inyecciones Intraventriculares , Masculino , Meduloblastoma/líquido cefalorraquídeo , Meduloblastoma/inmunología , Meduloblastoma/patología , Ratones , Metástasis de la Neoplasia , Receptores Quiméricos de Antígenos/administración & dosificación , Receptores Quiméricos de Antígenos/genética , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Linfocitos T/trasplante , Resultado del Tratamiento , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Medulloblastoma and central nervous system primitive neuroectodermal tumors (CNS-PNET) are aggressive, poorly differentiated brain tumors with limited effective therapies. Using Sleeping Beauty (SB) transposon mutagenesis, we identified novel genetic drivers of medulloblastoma and CNS-PNET. Cross-species gene expression analyses classified SB-driven tumors into distinct medulloblastoma and CNS-PNET subgroups, indicating they resemble human Sonic hedgehog and group 3 and 4 medulloblastoma and CNS neuroblastoma with FOXR2 activation. This represents the first genetically induced mouse model of CNS-PNET and a rare model of group 3 and 4 medulloblastoma. We identified several putative proto-oncogenes including Arhgap36, Megf10, and Foxr2. Genetic manipulation of these genes demonstrated a robust impact on tumorigenesis in vitro and in vivo. We also determined that FOXR2 interacts with N-MYC, increases C-MYC protein stability, and activates FAK/SRC signaling. Altogether, our study identified several promising therapeutic targets in medulloblastoma and CNS-PNET. SIGNIFICANCE: A transposon-induced mouse model identifies several novel genetic drivers and potential therapeutic targets in medulloblastoma and CNS-PNET.
Asunto(s)
Neoplasias Encefálicas/genética , Neoplasias Cerebelosas/genética , Meduloblastoma/genética , Tumores Neuroectodérmicos Primitivos/genética , Animales , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Transformación Celular Neoplásica/genética , Neoplasias Cerebelosas/metabolismo , Neoplasias Cerebelosas/patología , Elementos Transponibles de ADN/genética , Femenino , Factores de Transcripción Forkhead/genética , Proteínas Activadoras de GTPasa/biosíntesis , Proteínas Activadoras de GTPasa/genética , Humanos , Masculino , Meduloblastoma/metabolismo , Meduloblastoma/patología , Proteínas de la Membrana/genética , Ratones , Ratones Desnudos , Mutagénesis Insercional/métodos , Células-Madre Neurales/metabolismo , Células-Madre Neurales/patología , Tumores Neuroectodérmicos Primitivos/metabolismo , Tumores Neuroectodérmicos Primitivos/patología , PronósticoRESUMEN
Raf-1 is an important effector of Ras mediated signaling and is a critical regulator of the ERK/MAPK pathway. Raf-1 activation is controlled in part by phosphorylation on multiple residues, including an obligate phosphorylation site at serine 338. Previously PAK1 and casein kinase II have been implicated as serine 338 kinases. To identify novel kinases that phosphorylate this site, we tested the ability of group II PAKs (PAKs 4-6) to control serine 338 phosphorylation. We observed that all group II PAKs were efficient serine 338 kinases, although only PAK1 and PAK5 significantly stimulated Raf-1 kinase activity. We also showed that PAK5 forms a tight complex with Raf-1 in the cell, but not A-Raf or B-Raf. Importantly, we also demonstrated that the association of Raf-1 with PAK5 targets a subpopulation of Raf-1 to mitochondria. These data indicate that PAK5 is a potent regulator of Raf-1 activity and may control Raf-1 dependent signaling at mitochondria.
Asunto(s)
Mitocondrias/enzimología , Proteínas Proto-Oncogénicas c-raf/metabolismo , Quinasas p21 Activadas/metabolismo , Línea Celular , Activación Enzimática , Factor de Crecimiento Epidérmico/farmacología , Regulación Enzimológica de la Expresión Génica , Humanos , Mitocondrias/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosfoserina/metabolismo , Unión Proteica , Proteínas Proto-Oncogénicas c-raf/clasificación , Proteínas Proto-Oncogénicas c-raf/genética , Quinasas p21 Activadas/genéticaRESUMEN
microRNAs (miRNAs) have wide-ranging effects on large-scale gene regulation. As such, they play a vital role in dictating normal development, and their aberrant expression has been implicated in cancer. There has been a large body of research on the role of miRNAs in medulloblastoma, the most common malignant brain tumor of childhood. The identification of the 4 molecular subgroups with distinct biological, genetic, and transcriptional features has revolutionized the field of medulloblastoma research over the past 5 years. Despite this, the growing body of research on miRNAs in medulloblastoma has largely focused on the clinical entity of a single disease rather than the molecular subgroups. This review begins by highlighting the role of miRNAs in development and progresses to explore their myriad of implications in cancer. Medulloblastoma is characterized by increased proliferation, inhibition of apoptosis, and maintenance of stemness programs-features that are inadvertently regulated by altered expression patterns in miRNAs. This review aims to contextualize the large body of work on miRNAs within the framework of medulloblastoma subgroups. The goal of this review is to stimulate new areas of research, including potential therapeutics, within a rapidly growing field.