RESUMO
COVID survivors frequently experience lingering neurological symptoms that resemble cancer-therapy-related cognitive impairment, a syndrome for which white matter microglial reactivity and consequent neural dysregulation is central. Here, we explored the neurobiological effects of respiratory SARS-CoV-2 infection and found white-matter-selective microglial reactivity in mice and humans. Following mild respiratory COVID in mice, persistently impaired hippocampal neurogenesis, decreased oligodendrocytes, and myelin loss were evident together with elevated CSF cytokines/chemokines including CCL11. Systemic CCL11 administration specifically caused hippocampal microglial reactivity and impaired neurogenesis. Concordantly, humans with lasting cognitive symptoms post-COVID exhibit elevated CCL11 levels. Compared with SARS-CoV-2, mild respiratory influenza in mice caused similar patterns of white-matter-selective microglial reactivity, oligodendrocyte loss, impaired neurogenesis, and elevated CCL11 at early time points, but after influenza, only elevated CCL11 and hippocampal pathology persisted. These findings illustrate similar neuropathophysiology after cancer therapy and respiratory SARS-CoV-2 infection which may contribute to cognitive impairment following even mild COVID.
Assuntos
COVID-19 , Influenza Humana , Neoplasias , Animais , Humanos , Influenza Humana/patologia , Camundongos , Microglia/patologia , Bainha de Mielina , Neoplasias/patologia , SARS-CoV-2RESUMO
Chemotherapy results in a frequent yet poorly understood syndrome of long-term neurological deficits. Neural precursor cell dysfunction and white matter dysfunction are thought to contribute to this debilitating syndrome. Here, we demonstrate persistent depletion of oligodendrocyte lineage cells in humans who received chemotherapy. Developing a mouse model of methotrexate chemotherapy-induced neurological dysfunction, we find a similar depletion of white matter OPCs, increased but incomplete OPC differentiation, and a persistent deficit in myelination. OPCs from chemotherapy-naive mice similarly exhibit increased differentiation when transplanted into the microenvironment of previously methotrexate-exposed brains, indicating an underlying microenvironmental perturbation. Methotrexate results in persistent activation of microglia and subsequent astrocyte activation that is dependent on inflammatory microglia. Microglial depletion normalizes oligodendroglial lineage dynamics, myelin microstructure, and cognitive behavior after methotrexate chemotherapy. These findings indicate that methotrexate chemotherapy exposure is associated with persistent tri-glial dysregulation and identify inflammatory microglia as a therapeutic target to abrogate chemotherapy-related cognitive impairment. VIDEO ABSTRACT.
Assuntos
Disfunção Cognitiva/induzido quimicamente , Metotrexato/efeitos adversos , Oligodendroglia/efeitos dos fármacos , Animais , Encéfalo/metabolismo , Diferenciação Celular , Linhagem da Célula , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Tratamento Farmacológico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Metotrexato/farmacologia , Camundongos , Microglia/metabolismo , Bainha de Mielina/metabolismo , Fibras Nervosas Mielinizadas , Neurogênese/fisiologia , Neuroglia/metabolismo , Neurônios/efeitos dos fármacos , Oligodendroglia/metabolismo , Substância Branca/metabolismoRESUMO
Active neurons exert a mitogenic effect on normal neural precursor and oligodendroglial precursor cells, the putative cellular origins of high-grade glioma (HGG). By using optogenetic control of cortical neuronal activity in a patient-derived pediatric glioblastoma xenograft model, we demonstrate that active neurons similarly promote HGG proliferation and growth in vivo. Conditioned medium from optogenetically stimulated cortical slices promoted proliferation of pediatric and adult patient-derived HGG cultures, indicating secretion of activity-regulated mitogen(s). The synaptic protein neuroligin-3 (NLGN3) was identified as the leading candidate mitogen, and soluble NLGN3 was sufficient and necessary to promote robust HGG cell proliferation. NLGN3 induced PI3K-mTOR pathway activity and feedforward expression of NLGN3 in glioma cells. NLGN3 expression levels in human HGG negatively correlated with patient overall survival. These findings indicate the important role of active neurons in the brain tumor microenvironment and identify secreted NLGN3 as an unexpected mechanism promoting neuronal activity-regulated cancer growth.
Assuntos
Neoplasias Encefálicas/patologia , Moléculas de Adesão Celular Neuronais/metabolismo , Proliferação de Células , Glioma/patologia , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Adolescente , Sequência de Aminoácidos , Animais , Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , Xenoenxertos , Humanos , Masculino , Camundongos , Dados de Sequência Molecular , Transplante de Neoplasias , Neurônios/metabolismoRESUMO
The role of the nervous system in the regulation of cancer is increasingly appreciated. In gliomas, neuronal activity drives tumour progression through paracrine signalling factors such as neuroligin-3 and brain-derived neurotrophic factor1-3 (BDNF), and also through electrophysiologically functional neuron-to-glioma synapses mediated by AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors4,5. The consequent glioma cell membrane depolarization drives tumour proliferation4,6. In the healthy brain, activity-regulated secretion of BDNF promotes adaptive plasticity of synaptic connectivity7,8 and strength9-15. Here we show that malignant synapses exhibit similar plasticity regulated by BDNF. Signalling through the receptor tropomyosin-related kinase B16 (TrkB) to CAMKII, BDNF promotes AMPA receptor trafficking to the glioma cell membrane, resulting in increased amplitude of glutamate-evoked currents in the malignant cells. Linking plasticity of glioma synaptic strength to tumour growth, graded optogenetic control of glioma membrane potential demonstrates that greater depolarizing current amplitude promotes increased glioma proliferation. This potentiation of malignant synaptic strength shares mechanistic features with synaptic plasticity17-22 that contributes to memory and learning in the healthy brain23-26. BDNF-TrkB signalling also regulates the number of neuron-to-glioma synapses. Abrogation of activity-regulated BDNF secretion from the brain microenvironment or loss of glioma TrkB expression robustly inhibits tumour progression. Blocking TrkB genetically or pharmacologically abrogates these effects of BDNF on glioma synapses and substantially prolongs survival in xenograft models of paediatric glioblastoma and diffuse intrinsic pontine glioma. Together, these findings indicate that BDNF-TrkB signalling promotes malignant synaptic plasticity and augments tumour progression.
Assuntos
Adaptação Fisiológica , Glioma , Plasticidade Neuronal , Sinapses , Animais , Criança , Humanos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proliferação de Células , Progressão da Doença , Glioma/metabolismo , Glioma/patologia , Ácido Glutâmico/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Receptor trkB/genética , Receptor trkB/metabolismo , Receptores de AMPA/metabolismo , Transdução de Sinais , Sinapses/metabolismo , Microambiente Tumoral , OptogenéticaRESUMO
Development of effective targeted cancer therapies is fundamentally limited by our molecular understanding of disease pathogenesis. Diffuse intrinsic pontine glioma (DIPG) is a fatal malignancy of the childhood pons characterized by a unique substitution to methionine in histone H3 at lysine 27 (H3K27M) that results in globally altered epigenetic marks and oncogenic transcription. Through primary DIPG tumor characterization and isogenic oncohistone expression, we show that the same H3K27M mutation displays distinct modes of oncogenic reprogramming and establishes distinct enhancer architecture depending upon both the variant of histone H3 and the cell context in which the mutation occurs. Compared with non-malignant pediatric pontine tissue, we identify and functionally validate both shared and variant-specific pathophysiology. Altogether, we provide a powerful resource of epigenomic data in 25 primary DIPG samples and 5 rare normal pediatric pontine tissue samples, revealing clinically relevant functional distinctions previously unidentified in DIPG.
Assuntos
Glioma Pontino Intrínseco Difuso/genética , Histonas/genética , Encéfalo/patologia , Neoplasias Encefálicas/genética , Reprogramação Celular/genética , Glioma Pontino Intrínseco Difuso/metabolismo , Elementos Facilitadores Genéticos/genética , Epigênese Genética/genética , Epigenômica , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/genética , Glioma/genética , Glioma/metabolismo , Humanos , Lisina/genética , Mutação/genética , Ponte/metabolismo , Transdução de Sinais , Transcriptoma/fisiologiaRESUMO
High-grade gliomas are lethal brain cancers whose progression is robustly regulated by neuronal activity. Activity-regulated release of growth factors promotes glioma growth, but this alone is insufficient to explain the effect that neuronal activity exerts on glioma progression. Here we show that neuron and glioma interactions include electrochemical communication through bona fide AMPA receptor-dependent neuron-glioma synapses. Neuronal activity also evokes non-synaptic activity-dependent potassium currents that are amplified by gap junction-mediated tumour interconnections, forming an electrically coupled network. Depolarization of glioma membranes assessed by in vivo optogenetics promotes proliferation, whereas pharmacologically or genetically blocking electrochemical signalling inhibits the growth of glioma xenografts and extends mouse survival. Emphasizing the positive feedback mechanisms by which gliomas increase neuronal excitability and thus activity-regulated glioma growth, human intraoperative electrocorticography demonstrates increased cortical excitability in the glioma-infiltrated brain. Together, these findings indicate that synaptic and electrical integration into neural circuits promotes glioma progression.
Assuntos
Encéfalo/fisiopatologia , Sinapses Elétricas/patologia , Fenômenos Eletrofisiológicos , Glioma/fisiopatologia , Animais , Encéfalo/citologia , Membrana Celular/patologia , Proliferação de Células , Junções Comunicantes/patologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Neurônios/patologia , Optogenética , Potássio/metabolismo , Transmissão Sináptica , Células Tumorais CultivadasRESUMO
High-grade gliomas (HGG) are a devastating group of cancers, and represent the leading cause of brain tumour-related death in both children and adults. Therapies aimed at mechanisms intrinsic to glioma cells have translated to only limited success; effective therapeutic strategies will need also to target elements of the tumour microenvironment that promote glioma progression. Neuronal activity promotes the growth of a range of molecularly and clinically distinct HGG types, including adult and paediatric glioblastoma (GBM), anaplastic oligodendroglioma, and diffuse intrinsic pontine glioma (DIPG). An important mechanism that mediates this neural regulation of brain cancer is activity-dependent cleavage and secretion of the synaptic adhesion molecule neuroligin-3 (NLGN3), which promotes glioma proliferation through the PI3K-mTOR pathway. However, the necessity of NLGN3 for glioma growth, the proteolytic mechanism of NLGN3 secretion, and the further molecular consequences of NLGN3 secretion in glioma cells remain unknown. Here we show that HGG growth depends on microenvironmental NLGN3, identify signalling cascades downstream of NLGN3 binding in glioma, and determine a therapeutically targetable mechanism of secretion. Patient-derived orthotopic xenografts of paediatric GBM, DIPG and adult GBM fail to grow in Nlgn3 knockout mice. NLGN3 stimulates several oncogenic pathways, such as early focal adhesion kinase activation upstream of PI3K-mTOR, and induces transcriptional changes that include upregulation of several synapse-related genes in glioma cells. NLGN3 is cleaved from both neurons and oligodendrocyte precursor cells via the ADAM10 sheddase. ADAM10 inhibitors prevent the release of NLGN3 into the tumour microenvironment and robustly block HGG xenograft growth. This work defines a promising strategy for targeting NLGN3 secretion, which could prove transformative for HGG therapy.
Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Glioma/metabolismo , Glioma/patologia , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Proteína ADAM10/antagonistas & inibidores , Proteína ADAM10/metabolismo , Adulto , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Moléculas de Adesão Celular Neuronais/deficiência , Moléculas de Adesão Celular Neuronais/genética , Proliferação de Células , Criança , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Glioma/genética , Xenoenxertos , Humanos , Masculino , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Transplante de Neoplasias , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Neurônios/patologia , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Microambiente TumoralRESUMO
Persistent central nervous system (CNS) immune dysregulation and consequent dysfunction of multiple neural cell types is central to the neurobiological underpinnings of a cognitive impairment syndrome that can occur following traditional cancer therapies or certain infections. Immunotherapies have revolutionized cancer care for many tumor types, but the potential long-term cognitive sequelae are incompletely understood. Here, we demonstrate in mouse models that chimeric antigen receptor (CAR) T cell therapy for both CNS and non-CNS cancers can impair cognitive function and induce a persistent CNS immune response characterized by white matter microglial reactivity and elevated cerebrospinal fluid (CSF) cytokines and chemokines. Consequently, oligodendroglial homeostasis and hippocampal neurogenesis are disrupted. Microglial depletion rescues oligodendroglial deficits and cognitive performance in a behavioral test of attention and short-term memory function. Taken together, these findings illustrate similar mechanisms underlying immunotherapy-related cognitive impairment (IRCI) and cognitive impairment following traditional cancer therapies and other immune challenges.
RESUMO
High-grade gliomas (HGG) are deadly diseases for both adult and pediatric patients. Recently, it has been shown that neuronal activity promotes the progression of multiple subgroups of HGG. However, epigenetic mechanisms that govern this process remain elusive. Here we report that the chromatin remodeler chromodomain helicase DNA-binding protein 2 (CHD2) regulates neuron-glioma interactions in diffuse midline glioma (DMG) characterized by onco-histone H3.1K27M. Depletion of CHD2 in H3.1K27M DMG cells compromises cell viability and neuron-to-glioma synaptic connections in vitro, neuron-induced proliferation of H3.1K27M DMG cells in vitro and in vivo, activity-dependent calcium transients in vivo, and extends the survival of H3.1K27M DMG-bearing mice. Mechanistically, CHD2 coordinates with the transcription factor FOSL1 to control the expression of axon-guidance and synaptic genes in H3.1K27M DMG cells. Together, our study reveals a mechanism whereby CHD2 controls the intrinsic gene program of the H3.1K27M DMG subtype, which in turn regulates the tumor growth-promoting interactions of glioma cells with neurons. Significance: Neurons drive the proliferation and invasion of glioma cells. Here we show that chromatin remodeler chromodomain helicase DNA-binding protein 2 controls the epigenome and expression of axon-guidance and synaptic genes, thereby promoting neuron-induced proliferation of H3.1K27M diffuse midline glioma and the pathogenesis of this deadly disease.
Assuntos
Glioma , Neurônios , Humanos , Glioma/genética , Glioma/patologia , Glioma/metabolismo , Camundongos , Animais , Neurônios/metabolismo , Neurônios/patologia , Linhagem Celular Tumoral , Criança , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Proliferação de Células , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Proteínas de Ligação a DNARESUMO
Neural activity is increasingly recognized as a critical regulator of cancer growth. In the brain, neuronal activity robustly influences glioma growth both through paracrine mechanisms and through electrochemical integration of malignant cells into neural circuitry via neuron-to-glioma synapses, while perisynaptic neurotransmitter signaling drives breast cancer brain metastasis growth. Outside of the CNS, innervation of tumors such as prostate, breast, pancreatic and gastrointestinal cancers by peripheral nerves similarly regulates cancer progression. However, the extent to which the nervous system regulates lung cancer progression, either in the lung or when metastatic to brain, is largely unexplored. Small cell lung cancer (SCLC) is a lethal high-grade neuroendocrine tumor that exhibits a strong propensity to metastasize to the brain. Here we demonstrate that, similar to glioma, metastatic SCLC cells in the brain co-opt neuronal activity-regulated mechanisms to stimulate growth and progression. Optogenetic stimulation of cortical neuronal activity drives proliferation and invasion of SCLC brain metastases. In the brain, SCLC cells exhibit electrical currents and consequent calcium transients in response to neuronal activity, and direct SCLC cell membrane depolarization is sufficient to promote the growth of SCLC tumors. In the lung, vagus nerve transection markedly inhibits primary lung tumor formation, progression and metastasis, highlighting a critical role for innervation in overall SCLC initiation and progression. Taken together, these studies illustrate that neuronal activity plays a crucial role in dictating SCLC pathogenesis in both primary and metastatic sites.
RESUMO
Diffuse midline gliomas (DMGs) are universally lethal malignancies occurring chiefly during childhood and involving midline structures of the central nervous system, including thalamus, pons, and spinal cord. These molecularly related cancers are characterized by high prevalence of the histone H3K27M mutation. In search of effective therapeutic options, we examined multiple DMG cultures in sequential quantitative high-throughput screens (HTS) of 2706 approved and investigational drugs. This effort generated 19,936 single-agent dose responses that inspired a series of HTS-enabled drug combination assessments encompassing 9195 drug-drug examinations. Top combinations were validated across patient-derived cell cultures representing the major DMG genotypes. In vivo testing in patient-derived xenograft models validated the combination of the multi-histone deacetylase (HDAC) inhibitor panobinostat and the proteasome inhibitor marizomib as a promising therapeutic approach. Transcriptional and metabolomic surveys revealed substantial alterations to key metabolic processes and the cellular unfolded protein response after treatment with panobinostat and marizomib. Mitigation of drug-induced cytotoxicity and basal mitochondrial respiration with exogenous application of nicotinamide mononucleotide (NMN) or exacerbation of these phenotypes when blocking nicotinamide adenine dinucleotide (NAD+) production via nicotinamide phosphoribosyltransferase (NAMPT) inhibition demonstrated that metabolic catastrophe drives the combination-induced cytotoxicity. This study provides a comprehensive single-agent and combinatorial drug screen for DMG and identifies concomitant HDAC and proteasome inhibition as a promising therapeutic strategy that underscores underrecognized metabolic vulnerabilities in DMG.
Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Avaliação Pré-Clínica de Medicamentos , Glioma/tratamento farmacológico , Ensaios de Triagem em Larga Escala/métodos , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias do Tronco Encefálico/tratamento farmacológico , Morte Celular , Linhagem Celular Tumoral , Sinergismo Farmacológico , Feminino , Glioma/genética , Glioma/metabolismo , Humanos , Lactonas/farmacologia , Lactonas/uso terapêutico , Masculino , Metabolômica , Camundongos , Panobinostat/farmacologia , Panobinostat/uso terapêutico , Pirróis/farmacologia , Pirróis/uso terapêutico , Reprodutibilidade dos Testes , Análise de Sequência de RNA , Transcrição Gênica/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Diffuse intrinsic pontine glioma (DIPG) and other diffuse midline gliomas (DMGs) with mutated histone H3 K27M (H3-K27M)1-5 are aggressive and universally fatal pediatric brain cancers 6 . Chimeric antigen receptor (CAR)-expressing T cells have mediated impressive clinical activity in B cell malignancies7-10, and recent results suggest benefit in central nervous system malignancies11-13. Here, we report that patient-derived H3-K27M-mutant glioma cell cultures exhibit uniform, high expression of the disialoganglioside GD2. Anti-GD2 CAR T cells incorporating a 4-1BBz costimulatory domain 14 demonstrated robust antigen-dependent cytokine generation and killing of DMG cells in vitro. In five independent patient-derived H3-K27M+ DMG orthotopic xenograft models, systemic administration of GD2-targeted CAR T cells cleared engrafted tumors except for a small number of residual GD2lo glioma cells. To date, GD2-targeted CAR T cells have been well tolerated in clinical trials15-17. Although GD2-targeted CAR T cell administration was tolerated in the majority of mice bearing orthotopic xenografts, peritumoral neuroinflammation during the acute phase of antitumor activity resulted in hydrocephalus that was lethal in a fraction of animals. Given the precarious neuroanatomical location of midline gliomas, careful monitoring and aggressive neurointensive care management will be required for human translation. With a cautious multidisciplinary clinical approach, GD2-targeted CAR T cell therapy for H3-K27M+ diffuse gliomas of pons, thalamus and spinal cord could prove transformative for these lethal childhood cancers.
Assuntos
Neoplasias Encefálicas/imunologia , Gangliosídeos/metabolismo , Glioma/imunologia , Histonas/metabolismo , Imunoterapia Adotiva , Lisina/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Animais , Humanos , Metilação , Camundongos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Diffuse intrinsic pontine glioma (DIPG) is a fatal pediatric cancer with limited therapeutic options. The majority of cases of DIPG exhibit a mutation in histone-3 (H3K27M) that results in oncogenic transcriptional aberrancies. We show here that DIPG is vulnerable to transcriptional disruption using bromodomain inhibition or CDK7 blockade. Targeting oncogenic transcription through either of these methods synergizes with HDAC inhibition, and DIPG cells resistant to HDAC inhibitor therapy retain sensitivity to CDK7 blockade. Identification of super-enhancers in DIPG provides insights toward the cell of origin, highlighting oligodendroglial lineage genes, and reveals unexpected mechanisms mediating tumor viability and invasion, including potassium channel function and EPH receptor signaling. The findings presented demonstrate transcriptional vulnerabilities and elucidate previously unknown mechanisms of DIPG pathobiology.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Azepinas/farmacologia , Neoplasias do Tronco Encefálico/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/tratamento farmacológico , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Indóis/farmacologia , Fenilenodiaminas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia , Transcrição Gênica/efeitos dos fármacos , Triazóis/farmacologia , Animais , Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/metabolismo , Neoplasias do Tronco Encefálico/patologia , Proteínas de Ciclo Celular , Proliferação de Células/efeitos dos fármacos , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Glioma/genética , Glioma/metabolismo , Glioma/patologia , Histonas/genética , Histonas/metabolismo , Humanos , Masculino , Camundongos Endogâmicos NOD , Camundongos SCID , Mutação , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Panobinostat , Cultura Primária de Células , Interferência de RNA , Receptores da Família Eph/genética , Receptores da Família Eph/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Quinase Ativadora de Quinase Dependente de CiclinaRESUMO
Diffuse intrinsic pontine glioma (DIPG) is a fatal childhood cancer. We performed a chemical screen in patient-derived DIPG cultures along with RNA-seq analyses and integrated computational modeling to identify potentially effective therapeutic strategies. The multi-histone deacetylase inhibitor panobinostat demonstrated therapeutic efficacy both in vitro and in DIPG orthotopic xenograft models. Combination testing of panobinostat and the histone demethylase inhibitor GSK-J4 revealed that the two had synergistic effects. Together, these data suggest a promising therapeutic strategy for DIPG.
Assuntos
Benzazepinas/administração & dosagem , Neoplasias do Tronco Encefálico/tratamento farmacológico , Glioma/tratamento farmacológico , Ácidos Hidroxâmicos/administração & dosagem , Indóis/administração & dosagem , Pirimidinas/administração & dosagem , Animais , Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/patologia , Modelos Animais de Doenças , Sinergismo Farmacológico , Glioma/genética , Glioma/patologia , Humanos , Panobinostat , Análise de Sequência de RNA , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Myelination of the central nervous system requires the generation of functionally mature oligodendrocytes from oligodendrocyte precursor cells (OPCs). Electrically active neurons may influence OPC function and selectively instruct myelination of an active neural circuit. In this work, we use optogenetic stimulation of the premotor cortex in awake, behaving mice to demonstrate that neuronal activity elicits a mitogenic response of neural progenitor cells and OPCs, promotes oligodendrogenesis, and increases myelination within the deep layers of the premotor cortex and subcortical white matter. We further show that this neuronal activity-regulated oligodendrogenesis and myelination is associated with improved motor function of the corresponding limb. Oligodendrogenesis and myelination appear necessary for the observed functional improvement, as epigenetic blockade of oligodendrocyte differentiation and myelin changes prevents the activity-regulated behavioral improvement.
Assuntos
Diferenciação Celular , Córtex Motor/fisiologia , Bainha de Mielina/metabolismo , Fibras Nervosas Mielinizadas/metabolismo , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia , Oligodendroglia/citologia , Animais , Comportamento Animal/fisiologia , Linhagem da Célula , Proliferação de Células , Channelrhodopsins , Corpo Caloso/citologia , Corpo Caloso/fisiologia , Camundongos , Camundongos Mutantes , Atividade Motora/fisiologia , Córtex Motor/citologia , Antígenos Thy-1/genéticaRESUMO
Hedgehog signaling drives oncogenesis in several cancers, and strategies targeting this pathway have been developed, most notably through inhibition of Smoothened (SMO). However, resistance to Smoothened inhibitors occurs by genetic changes of Smoothened or other downstream Hedgehog components. Here we overcome these resistance mechanisms by modulating GLI transcription through inhibition of bromo and extra C-terminal (BET) bromodomain proteins. We show that BRD4 and other BET bromodomain proteins regulate GLI transcription downstream of SMO and suppressor of fused (SUFU), and chromatin immunoprecipitation studies reveal that BRD4 directly occupies GLI1 and GLI2 promoters, with a substantial decrease in engagement of these sites after treatment with JQ1, a small-molecule inhibitor targeting BRD4. Globally, genes associated with medulloblastoma-specific GLI1 binding sites are downregulated in response to JQ1 treatment, supporting direct regulation of GLI activity by BRD4. Notably, patient- and GEMM (genetically engineered mouse model)-derived Hedgehog-driven tumors (basal cell carcinoma, medulloblastoma and atypical teratoid rhabdoid tumor) respond to JQ1 even when harboring genetic lesions rendering them resistant to Smoothened antagonists. Altogether, our results reveal BET proteins as critical regulators of Hedgehog pathway transcriptional output and nominate BET bromodomain inhibitors as a strategy for treating Hedgehog-driven tumors with emerged or a priori resistance to Smoothened antagonists.