RESUMEN
Genetic drivers of cancer can be dysregulated through epigenetic modifications of DNA. Although the critical role of DNA 5-methylcytosine (5mC) in the regulation of transcription is recognized, the functions of other non-canonical DNA modifications remain obscure. Here, we report the identification of novel N6-methyladenine (N6-mA) DNA modifications in human tissues and implicate this epigenetic mark in human disease, specifically the highly malignant brain cancer glioblastoma. Glioblastoma markedly upregulated N6-mA levels, which co-localized with heterochromatic histone modifications, predominantly H3K9me3. N6-mA levels were dynamically regulated by the DNA demethylase ALKBH1, depletion of which led to transcriptional silencing of oncogenic pathways through decreasing chromatin accessibility. Targeting the N6-mA regulator ALKBH1 in patient-derived human glioblastoma models inhibited tumor cell proliferation and extended the survival of tumor-bearing mice, supporting this novel DNA modification as a potential therapeutic target for glioblastoma. Collectively, our results uncover a novel epigenetic node in cancer through the DNA modification N6-mA.
Asunto(s)
Adenina/análogos & derivados , Neoplasias Encefálicas/patología , Metilación de ADN , Glioblastoma/patología , Adenina/análisis , Adenina/química , Adulto , Anciano , Histona H2a Dioxigenasa, Homólogo 1 de AlkB/antagonistas & inhibidores , Histona H2a Dioxigenasa, Homólogo 1 de AlkB/genética , Histona H2a Dioxigenasa, Homólogo 1 de AlkB/metabolismo , Animales , Astrocitos/citología , Astrocitos/metabolismo , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/mortalidad , Hipoxia de la Célula , Niño , Epigenómica , Femenino , Glioblastoma/metabolismo , Glioblastoma/mortalidad , Heterocromatina/metabolismo , Histonas/metabolismo , Humanos , Estimación de Kaplan-Meier , Masculino , Ratones , Persona de Mediana Edad , Células Madre Neoplásicas/citología , Células Madre Neoplásicas/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Growth factor receptors rank among the most important oncogenic pathways, but pharmacologic inhibitors often demonstrate limited benefit as monotherapy. Here, we show that epidermal growth factor receptor (EGFR) signaling repressed N6-methyladenosine (m6A) levels in glioblastoma stem cells (GSCs), whereas genetic or pharmacologic EGFR targeting elevated m6A levels. Activated EGFR induced non-receptor tyrosine kinase SRC to phosphorylate the m6A demethylase, AlkB homolog 5 (ALKBH5), thereby inhibiting chromosomal maintenance 1 (CRM1)-mediated nuclear export of ALKBH5 to permit sustained mRNA m6A demethylation in the nucleus. ALKBH5 critically regulated ferroptosis through m6A modulation and YTH N6-methyladenosine RNA binding protein (YTHDF2)-mediated decay of the glutamate-cysteine ligase modifier subunit (GCLM). Pharmacologic targeting of ALKBH5 augmented the anti-tumor efficacy of EGFR and GCLM inhibitors, supporting an EGFR-ALKBH5-GCLM oncogenic axis. Collectively, EGFR reprograms the epitranscriptomic landscape through nuclear retention of the ALKBH5 demethylase to protect against ferroptosis, offering therapeutic paradigms for the treatment of lethal cancers.
Asunto(s)
Desmetilasa de ARN, Homólogo 5 de AlkB , Receptores ErbB , Ferroptosis , Glioblastoma , Humanos , Adenosina/metabolismo , Desmetilasa de ARN, Homólogo 5 de AlkB/genética , Desmetilasa de ARN, Homólogo 5 de AlkB/metabolismo , Receptores ErbB/genética , Ferroptosis/genética , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , ARN Mensajero/genéticaRESUMEN
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.
Asunto(s)
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
Sex can be an important determinant of cancer phenotype, and exploring sex-biased tumor biology holds promise for identifying novel therapeutic targets and new approaches to cancer treatment. In an established isogenic murine model of glioblastoma (GBM), we discovered correlated transcriptome-wide sex differences in gene expression, H3K27ac marks, large Brd4-bound enhancer usage, and Brd4 localization to Myc and p53 genomic binding sites. These sex-biased gene expression patterns were also evident in human glioblastoma stem cells (GSCs). These observations led us to hypothesize that Brd4-bound enhancers might underlie sex differences in stem cell function and tumorigenicity in GBM. We found that male and female GBM cells exhibited sex-specific responses to pharmacological or genetic inhibition of Brd4. Brd4 knockdown or pharmacologic inhibition decreased male GBM cell clonogenicity and in vivo tumorigenesis while increasing both in female GBM cells. These results were validated in male and female patient-derived GBM cell lines. Furthermore, analysis of the Cancer Therapeutic Response Portal of human GBM samples segregated by sex revealed that male GBM cells are significantly more sensitive to BET (bromodomain and extraterminal) inhibitors than are female cells. Thus, Brd4 activity is revealed to drive sex differences in stem cell and tumorigenic phenotypes, which can be abrogated by sex-specific responses to BET inhibition. This has important implications for the clinical evaluation and use of BET inhibitors.
Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Glioblastoma/metabolismo , Proteínas Nucleares/metabolismo , Factores Sexuales , Factores de Transcripción/metabolismo , Animales , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Proliferación Celular/genética , Femenino , Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/genética , Glioblastoma/genética , Histonas/metabolismo , Humanos , Masculino , Ratones , Proteínas Nucleares/fisiología , Unión Proteica , Proteínas Proto-Oncogénicas c-myc/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos/genética , Caracteres Sexuales , Factores de Transcripción/fisiología , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
N6-methyladenosine (m6A) is a common modification on endogenous RNA transcripts in mammalian cells. Technologies to precisely modify the RNA m6A levels at specific transcriptomic loci empower interrogation of biological functions of epitranscriptomic modifications. Here, we developed a bidirectional dCasRx epitranscriptome editing platform composed of a nuclear-localized dCasRx conjugated with either a methyltransferase, METTL3, or a demethylase, ALKBH5, to manipulate methylation events at targeted m6A sites. Leveraging this platform, we specifically and efficiently edited m6A modifications at targeted sites, reflected in gene expression and cell proliferation. We employed the dCasRx epitranscriptomic editor system to elucidate the molecular function of m6A-binding proteins YTHDF paralogs (YTHDF1, YTHDF2 and YTHDF3), revealing that YTHDFs promote m6A-mediated mRNA degradation. Collectively, our dCasRx epitranscriptome perturbation platform permits site-specific m6A editing for delineating of functional roles of individual m6A modifications in the mammalian epitranscriptome.
Asunto(s)
Adenosina/análogos & derivados , Desmetilasa de ARN, Homólogo 5 de AlkB/metabolismo , Metiltransferasas/metabolismo , ARN Mensajero/metabolismo , Adenosina/metabolismo , Desmetilasa de ARN, Homólogo 5 de AlkB/genética , Proteínas Asociadas a CRISPR/genética , Proliferación Celular , Células Cultivadas , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Metiltransferasas/genética , Células Madre Neoplásicas/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Procesamiento Postranscripcional del ARN , ARN Mensajero/química , Proteínas de Unión al ARN/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , TranscriptomaRESUMEN
Glioblastoma (GBM) ranks among the most lethal of human malignancies with GBM stem cells (GSCs) that contribute to tumor growth and therapeutic resistance. Identification and isolation of GSCs continue to be a challenge, as definitive methods to purify these cells for study or targeting are lacking. Here, we leveraged orthogonal in vitro and in vivo phage display biopanning strategies to isolate a single peptide with GSC-specific binding properties. In silico analysis of this peptide led to the isolation of EYA1 (Eyes Absent 1), a tyrosine phosphatase and transcriptional coactivator. Validating the phage discovery methods, EYA1 was preferentially expressed in GSCs compared to differentiated tumor progeny. MYC is a central mediator of GSC maintenance but has been resistant to direct targeting strategies. Based on correlation and colocalization of EYA1 and MYC, we interrogated a possible interaction, revealing binding of EYA1 to MYC and loss of MYC expression upon targeting EYA1. Supporting a functional role for EYA1, targeting EYA1 expression decreased GSC proliferation, migration, and self-renewal in vitro and tumor growth in vivo. Collectively, our results suggest that phage display can identify novel therapeutic targets in stem-like tumor cells and that an EYA1-MYC axis represents a potential therapeutic paradigm for GBM.
Asunto(s)
Bacteriófagos , Neoplasias Encefálicas , Glioblastoma , Bacteriófagos/metabolismo , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Proliferación Celular , Glioblastoma/patología , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Células Madre Neoplásicas/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Tirosina Fosfatasas/genética , Proteínas Tirosina Fosfatasas/metabolismoRESUMEN
Glioblastoma ranks among the most aggressive and lethal of all human cancers. Self-renewing, highly tumorigenic glioblastoma stem cells (GSCs) contribute to therapeutic resistance and maintain cellular heterogeneity. Here, we interrogated superenhancer landscapes of primary glioblastoma specimens and patient-derived GSCs, revealing a kelch domain-containing gene, specifically Kelch domain containing 8A (KLHDC8A) with a previously unknown function as an epigenetically driven oncogene. Targeting KLHDC8A decreased GSC proliferation and self-renewal, induced apoptosis, and impaired in vivo tumor growth. Transcription factor control circuitry analyses revealed that the master transcriptional regulator SOX2 stimulated KLHDC8A expression. Mechanistically, KLHDC8A bound chaperonin-containing TCP1 (CCT) to promote the assembly of primary cilia to activate hedgehog signaling. KLHDC8A expression correlated with Aurora B/C Kinase inhibitor activity, which induced primary cilia and hedgehog signaling. Combinatorial targeting of Aurora B/C kinase and hedgehog displayed augmented benefit against GSC proliferation. Collectively, superenhancer-based discovery revealed KLHDC8A as what we believe to be a novel molecular target of cancer stem cells that promotes ciliogenesis to activate the hedgehog pathway, offering insights into therapeutic vulnerabilities for glioblastoma treatment.
Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Glioma , Humanos , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Proliferación Celular , Glioblastoma/patología , Glioma/metabolismo , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Células Madre Neoplásicas/patología , Transducción de SeñalRESUMEN
In silico interrogation of glioblastoma (GBM) in The Cancer Genome Atlas (TCGA) revealed upregulation of GNA12 (Gα12), encoding the alpha subunit of the heterotrimeric G-protein G12, concomitant with overexpression of multiple G-protein coupled receptors (GPCRs) that signal through Gα12. Glioma stem cell lines from patient-derived xenografts also showed elevated levels of Gα12. Knockdown (KD) of Gα12 was carried out in two different human GBM stem cell (GSC) lines. Tumors generated in vivo by orthotopic injection of Gα12KD GSC cells showed reduced invasiveness, without apparent changes in tumor size or survival relative to control GSC tumor-bearing mice. Transcriptional profiling of GSC-23 cell tumors revealed significant differences between WT and Gα12KD tumors including reduced expression of genes associated with the extracellular matrix, as well as decreased expression of stem cell genes and increased expression of several proneural genes. Thrombospondin-1 (THBS1), one of the genes most repressed by Gα12 knockdown, was shown to be required for Gα12-mediated cell migration in vitro and for in vivo tumor invasion. Chemogenetic activation of GSC-23 cells harboring a Gα12-coupled DREADD also increased THBS1 expression and in vitro invasion. Collectively, our findings implicate Gα12 signaling in regulation of transcriptional reprogramming that promotes invasiveness, highlighting this as a potential signaling node for therapeutic intervention.
Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Humanos , Animales , Ratones , Subunidades alfa de la Proteína de Unión al GTP G12-G13/genética , Subunidades alfa de la Proteína de Unión al GTP G12-G13/metabolismo , Glioblastoma/genética , Glioblastoma/patología , Transducción de Señal , Procesos Neoplásicos , Regulación hacia Arriba , Línea Celular Tumoral , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Proliferación CelularRESUMEN
Glioblastoma is the most malignant primary brain tumor, the prognosis of which remains dismal even with aggressive surgical, medical, and radiation therapies. Glioblastoma stem cells (GSCs) promote therapeutic resistance and cellular heterogeneity due to their self-renewal properties and capacity for plasticity. To understand the molecular processes essential for maintaining GSCs, we performed an integrative analysis comparing active enhancer landscapes, transcriptional profiles, and functional genomics profiles of GSCs and non-neoplastic neural stem cells (NSCs). We identified sorting nexin 10 (SNX10), an endosomal protein sorting factor, as selectively expressed in GSCs compared with NSCs and essential for GSC survival. Targeting SNX10 impaired GSC viability and proliferation, induced apoptosis, and reduced self-renewal capacity. Mechanistically, GSCs utilized endosomal protein sorting to promote platelet-derived growth factor receptor ß (PDGFRß) proliferative and stem cell signaling pathways through posttranscriptional regulation of the PDGFR tyrosine kinase. Targeting SNX10 expression extended survival of orthotopic xenograft-bearing mice, and high SNX10 expression correlated with poor glioblastoma patient prognosis, suggesting its potential clinical importance. Thus, our study reveals an essential connection between endosomal protein sorting and oncogenic receptor tyrosine kinase signaling and suggests that targeting endosomal sorting may represent a promising therapeutic approach for glioblastoma treatment.
Asunto(s)
Glioblastoma , Humanos , Animales , Ratones , Glioblastoma/tratamiento farmacológico , Nexinas de Clasificación/genética , Células Madre Neoplásicas/metabolismo , Transducción de Señal , Proteínas Tirosina Quinasas/metabolismo , Receptores del Factor de Crecimiento Derivado de Plaquetas/metabolismoRESUMEN
Glioblastoma (GBM) ranks among the most lethal of human cancers, containing glioma stem cells (GSCs) that display therapeutic resistance. Here, we report that the lncRNA INHEG is highly expressed in GSCs compared to differentiated glioma cells (DGCs) and promotes GSC self-renewal and tumorigenicity through control of rRNA 2'-O-methylation. INHEG induces the interaction between SUMO2 E3 ligase TAF15 and NOP58, a core component of snoRNP that guides rRNA methylation, to regulate NOP58 sumoylation and accelerate the C/D box snoRNP assembly. INHEG activation enhances rRNA 2'-O-methylation, thereby increasing the expression of oncogenic proteins including EGFR, IGF1R, CDK6 and PDGFRB in glioma cells. Taken together, this study identifies a lncRNA that connects snoRNP-guided rRNA 2'-O-methylation to upregulated protein translation in GSCs, supporting an axis for potential therapeutic targeting of gliomas.
Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Glioma , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Metilación , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Ribonucleoproteínas Nucleolares Pequeñas/metabolismo , Células Madre Neoplásicas/metabolismo , Glioma/genética , Glioma/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Línea Celular TumoralRESUMEN
Adults with intellectual or developmental disability (IDD) comprise 1-2% of the population worldwide. IDD is a significant risk factor for premature morbidity or mortality. This is likely due in part to preventable health conditions, which are modifiable with the intervention of direct care providers in areas including nutrition, promotion of an active lifestyle and effective identification of health or functional deterioration. Adults with IDD are also at increased risk for neglect or mistreatment, a finding that has been documented across multiple countries and in a variety of care settings. Contributing factors include resource availability, lack of person-centered care, management culture and care worker training. Practical and economical interventions may address the known disparities and challenges facing the large community of adults with IDD. To promote person-centered care, improve record-keeping/documentation, and aid in protecting the health and safety of this vulnerable population, we propose incorporation of a video into the evaluation of adults with IDD living outside the home.
Asunto(s)
Discapacidades del Desarrollo , Discapacidad Intelectual , Adulto , Niño , Humanos , Morbilidad , Factores de RiesgoRESUMEN
Glioblastoma is the most prevalent primary malignant brain tumor in adults and is characterized by poor prognosis and universal tumor recurrence. Effective glioblastoma treatments are lacking, in part due to somatic mutations and epigenetic reprogramming that alter gene expression and confer drug resistance. To investigate recurrently dysregulated genes in glioblastoma, we interrogated allele-specific expression (ASE), the difference in expression between two alleles of a gene, in glioblastoma stem cells (GSC) derived from 43 patients. A total of 118 genes were found with recurrent ASE preferentially in GSCs compared with normal tissues. These genes were enriched for apoptotic regulators, including schlafen family member 11 (SLFN11). Loss of SLFN11 gene expression was associated with aberrant promoter methylation and conferred resistance to chemotherapy and PARP inhibition. Conversely, low SLFN11 expression rendered GSCs susceptible to the oncolytic flavivirus Zika. This discovery effort based upon ASE revealed novel points of vulnerability in GSCs, suggesting a potential alternative treatment strategy for chemotherapy-resistant glioblastoma. SIGNIFICANCE: Assessing allele-specific expression reveals genes with recurrent cis-regulatory changes that are enriched in glioblastoma stem cells, including SLFN11, which modulates chemotherapy resistance and susceptibility to the oncolytic Zika virus.
Asunto(s)
Estudios de Asociación Genética/métodos , Glioblastoma/genética , Glioblastoma/terapia , Alelos , Línea Celular Tumoral , HumanosRESUMEN
Glioblastoma (GBM) is the most common and lethal primary malignant brain tumor, containing GBM stem cells (GSCs) that contribute to therapeutic resistance and relapse. Exposing potential GSC vulnerabilities may provide therapeutic strategies against GBM. Here, we interrogated the role of adenosine-to-inosine (A-to-I) RNA editing mediated by adenosine deaminase acting on RNA 1 (ADAR1) in GSCs and found that both ADAR1 and global RNA editomes were elevated in GSCs compared with normal neural stem cells. ADAR1 inactivation or blocking of the upstream JAK/STAT pathway through TYK2 inhibition impaired GSC self-renewal and stemness. Downstream of ADAR1, RNA editing of the 3'-UTR of GM2A, a key ganglioside catabolism activator, proved to be critical, as interference with ganglioside catabolism and disruption of ADAR1 showed a similar functional impact on GSCs. These findings reveal that RNA editing links ganglioside catabolism to GSC self-renewal and stemness, exposing a potential vulnerability of GBM for therapeutic intervention.
Asunto(s)
Glioblastoma , Células-Madre Neurales , Proteínas de Unión al ARN/metabolismo , Adenosina Desaminasa/genética , Gangliósidos/metabolismo , Glioblastoma/metabolismo , Humanos , Quinasas Janus/genética , Quinasas Janus/metabolismo , Recurrencia Local de Neoplasia/metabolismo , Células Madre Neoplásicas/patología , Células-Madre Neurales/metabolismo , ARN , Edición de ARN , Factores de Transcripción STAT , Transducción de Señal/genéticaRESUMEN
Natural killer (NK) cells are known to mediate killing of various cancer types, but tumor cells can develop resistance mechanisms to escape NK cell-mediated killing. Here, we use a "two cell type" whole genome CRISPR-Cas9 screening system to discover key regulators of tumor sensitivity and resistance to NK cell-mediated cytotoxicity in human glioblastoma stem cells (GSC). We identify CHMP2A as a regulator of GSC resistance to NK cell-mediated cytotoxicity and we confirm these findings in a head and neck squamous cells carcinoma (HNSCC) model. We show that deletion of CHMP2A activates NF-κB in tumor cells to mediate increased chemokine secretion that promotes NK cell migration towards tumor cells. In the HNSCC model we demonstrate that CHMP2A mediates tumor resistance to NK cells via secretion of extracellular vesicles (EVs) that express MICA/B and TRAIL. These secreted ligands induce apoptosis of NK cells to inhibit their antitumor activity. To confirm these in vitro studies, we demonstrate that deletion of CHMP2A in CAL27 HNSCC cells leads to increased NK cell-mediated killing in a xenograft immunodeficient mouse model. These findings illustrate a mechanism of tumor immune escape through EVs secretion and identify inhibition of CHMP2A and related targets as opportunities to improve NK cell-mediated immunotherapy.
Asunto(s)
Neoplasias de Cabeza y Cuello , Células Asesinas Naturales , Animales , Apoptosis/genética , Línea Celular Tumoral , Citotoxicidad Inmunológica , Complejos de Clasificación Endosomal Requeridos para el Transporte , Neoplasias de Cabeza y Cuello/genética , Humanos , Inmunoterapia , Ratones , Carcinoma de Células Escamosas de Cabeza y Cuello/genéticaRESUMEN
Glioblastomas are universally fatal cancers and contain self-renewing glioblastoma stem cells (GSCs) that initiate tumors. Traditional anticancer drug discovery based on in vitro cultures tends to identify targets with poor therapeutic indices and fails to accurately model the effects of the tumor microenvironment. Here, leveraging in vivo genetic screening, we identified the histone H3 lysine 4 trimethylation (H3K4me3) regulator DPY30 (Dpy-30 histone methyltransferase complex regulatory subunit) as an in vivospecific glioblastoma dependency. On the basis of the hypothesis that in vivo epigenetic regulation may define critical GSC dependencies, we interrogated active chromatin landscapes of GSCs derived from intracranial patient-derived xenografts (PDXs) and cell culture through H3K4me3 chromatin immunoprecipitation and transcriptome analyses. Intracranial-specific genes marked by H3K4me3 included FOS, NFκB, and phosphodiesterase (PDE) family members. In intracranial PDX tumors, DPY30 regulated angiogenesis and hypoxia pathways in an H3K4me3-dependent manner but was dispensable in vitro in cultured GSCs. PDE4B was a key downstream effector of DPY30, and the PDE4 inhibitor rolipram preferentially targeted DPY30-expressing cells and impaired PDX tumor growth in mice without affecting tumor cells cultured in vitro. Collectively, the MLL/SET1 (mixed lineage leukemia/SET domain-containing 1, histone lysine methyltransferase) complex member DPY30 selectively regulates H3K4me3 modification on genes critical to support angiogenesis and tumor growth in vivo, suggesting the DPY30-PDE4B axis as a specific therapeutic target in glioblastoma.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4 , Glioblastoma , Factores de Transcripción , Animales , Cromatina , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/metabolismo , Epigénesis Genética , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Humanos , Ratones , Células Madre/metabolismo , Factores de Transcripción/metabolismo , Microambiente TumoralRESUMEN
Dysregulated growth factor receptor pathways, RNA modifications, and metabolism each promote tumor heterogeneity. Here, we demonstrate that platelet-derived growth factor (PDGF) signaling induces N6-methyladenosine (m6A) accumulation in glioblastoma (GBM) stem cells (GSCs) to regulate mitophagy. PDGF ligands stimulate early growth response 1 (EGR1) transcription to induce methyltransferase-like 3 (METTL3) to promote GSC proliferation and self-renewal. Targeting the PDGF-METTL3 axis inhibits mitophagy by regulating m6A modification of optineurin (OPTN). Forced OPTN expression phenocopies PDGF inhibition, and OPTN levels portend longer survival of GBM patients; these results suggest a tumor-suppressive role for OPTN. Pharmacologic targeting of METTL3 augments anti-tumor efficacy of PDGF receptor (PDGFR) and mitophagy inhibitors in vitro and in vivo. Collectively, we define PDGF signaling as an upstream regulator of oncogenic m6A regulation, driving tumor metabolism to promote cancer stem cell maintenance, highlighting PDGF-METTL3-OPTN signaling as a GBM therapeutic target.
Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Adenosina/análogos & derivados , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Metiltransferasas/metabolismo , Mitofagia , Células Madre Neoplásicas/patología , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Factor de Crecimiento Derivado de Plaquetas/farmacologíaRESUMEN
Glioblastoma (GBM) is the most lethal primary brain cancer characterized by therapeutic resistance, which is promoted by GBM stem cells (GSC). Here, we interrogated gene expression and whole-genome CRISPR/Cas9 screening in a large panel of patient-derived GSCs, differentiated GBM cells (DGC), and neural stem cells (NSC) to identify master regulators of GSC stemness, revealing an essential transcription state with increased RNA polymerase II-mediated transcription. The YY1 and transcriptional CDK9 complex was essential for GSC survival and maintenance in vitro and in vivo. YY1 interacted with CDK9 to regulate transcription elongation in GSCs. Genetic or pharmacologic targeting of the YY1-CDK9 complex elicited RNA m6A modification-dependent interferon responses, reduced regulatory T-cell infiltration, and augmented efficacy of immune checkpoint therapy in GBM. Collectively, these results suggest that YY1-CDK9 transcription elongation complex defines a targetable cell state with active transcription, suppressed interferon responses, and immunotherapy resistance in GBM. SIGNIFICANCE: Effective strategies to rewire immunosuppressive microenvironment and enhance immunotherapy response are still lacking in GBM. YY1-driven transcriptional elongation machinery represents a druggable target to activate interferon response and enhance anti-PD-1 response through regulating the m6A modification program, linking epigenetic regulation to immunomodulatory function in GBM.This article is highlighted in the In This Issue feature, p. 275.
Asunto(s)
Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Inmunoterapia , Animales , Neoplasias Encefálicas/genética , Epigénesis Genética , Femenino , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Humanos , Masculino , Ratones , Persona de Mediana Edad , Células Madre Neoplásicas/metabolismo , Microambiente TumoralRESUMEN
Meningiomas are the most common primary intracranial tumors. There are no effective medical therapies for meningioma patients, and new treatments have been encumbered by limited understanding of meningioma biology. Here, we use DNA methylation profiling on 565 meningiomas integrated with genetic, transcriptomic, biochemical, proteomic and single-cell approaches to show meningiomas are composed of three DNA methylation groups with distinct clinical outcomes, biological drivers and therapeutic vulnerabilities. Merlin-intact meningiomas (34%) have the best outcomes and are distinguished by NF2/Merlin regulation of susceptibility to cytotoxic therapy. Immune-enriched meningiomas (38%) have intermediate outcomes and are distinguished by immune infiltration, HLA expression and lymphatic vessels. Hypermitotic meningiomas (28%) have the worst outcomes and are distinguished by convergent genetic and epigenetic mechanisms driving the cell cycle and resistance to cytotoxic therapy. To translate these findings into clinical practice, we show cytostatic cell cycle inhibitors attenuate meningioma growth in cell culture, organoids, xenografts and patients.
Asunto(s)
Neoplasias Meníngeas , Meningioma , Metilación de ADN/genética , Humanos , Neoplasias Meníngeas/genética , Meningioma/genética , Neurofibromina 2/genética , ProteómicaRESUMEN
Glioblastoma ranks among the most lethal of primary brain malignancies, with glioblastoma stem cells (GSCs) at the apex of tumor cellular hierarchies. Here, to discover novel therapeutic GSC targets, we interrogated gene expression profiles from GSCs, differentiated glioblastoma cells (DGCs), and neural stem cells (NSCs), revealing EYA2 as preferentially expressed by GSCs. Targeting EYA2 impaired GSC maintenance and induced cell cycle arrest, apoptosis, and loss of self-renewal. EYA2 displayed novel localization to centrosomes in GSCs, and EYA2 tyrosine (Tyr) phosphatase activity was essential for proper mitotic spindle assembly and survival of GSCs. Inhibition of the EYA2 Tyr phosphatase activity, via genetic or pharmacological means, mimicked EYA2 loss in GSCs in vitro and extended the survival of tumor-bearing mice. Supporting the clinical relevance of these findings, EYA2 portends poor patient prognosis in glioblastoma. Collectively, our data indicate that EYA2 phosphatase function plays selective critical roles in the growth and survival of GSCs, potentially offering a high therapeutic index for EYA2 inhibitors.
Asunto(s)
Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Células Madre Neoplásicas/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Tirosina Fosfatasas/metabolismo , Animales , Encéfalo/metabolismo , Muerte Celular/fisiología , Diferenciación Celular/fisiología , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica/fisiología , Humanos , Masculino , Ratones , Células-Madre Neurales/metabolismoRESUMEN
Glioblastoma is a universally lethal cancer driven by glioblastoma stem cells (GSC). Here, we interrogated N 6-methyladenosine (m6A) mRNA modifications in GSCs by methyl RNA immunoprecipitation followed by sequencing and transcriptome analysis, finding transcripts marked by m6A often upregulated compared with normal neural stem cells (NSC). Interrogating m6A regulators, GSCs displayed preferential expression, as well as in vitro and in vivo dependency, of the m6A reader YTHDF2, in contrast to NSCs. Although YTHDF2 has been reported to destabilize mRNAs, YTHDF2 stabilized MYC and VEGFA transcripts in GSCs in an m6A-dependent manner. We identified IGFBP3 as a downstream effector of the YTHDF2-MYC axis in GSCs. The IGF1/IGF1R inhibitor linsitinib preferentially targeted YTHDF2-expressing cells, inhibiting GSC viability without affecting NSCs and impairing in vivo glioblastoma growth. Thus, YTHDF2 links RNA epitranscriptomic modifications and GSC growth, laying the foundation for the YTHDF2-MYC-IGFBP3 axis as a specific and novel therapeutic target in glioblastoma. SIGNIFICANCE: Epitranscriptomics promotes cellular heterogeneity in cancer. RNA m6A landscapes of cancer and NSCs identified cell type-specific dependencies and therapeutic vulnerabilities. The m6A reader YTHDF2 stabilized MYC mRNA specifically in cancer stem cells. Given the challenge of targeting MYC, YTHDF2 presents a therapeutic target to perturb MYC signaling in glioblastoma.This article is highlighted in the In This Issue feature, p. 211.