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1.
Genes Dev ; 38(9-10): 360-379, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38811170

RESUMEN

Glioblastoma (GBM) is the most aggressive primary brain cancer. These tumors exhibit high intertumoral and intratumoral heterogeneity in neoplastic and nonneoplastic compartments, low lymphocyte infiltration, and high abundance of myeloid subsets that together create a highly protumorigenic immunosuppressive microenvironment. Moreover, heterogeneous GBM cells infiltrate adjacent brain tissue, remodeling the neural microenvironment to foster tumor electrochemical coupling with neurons and metabolic coupling with nonneoplastic astrocytes, thereby driving growth. Here, we review heterogeneity in the GBM microenvironment and its role in low-to-high-grade glioma transition, concluding with a discussion of the challenges of therapeutically targeting the tumor microenvironment and outlining future research opportunities.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Microambiente Tumoral , Humanos , Glioblastoma/terapia , Glioblastoma/fisiopatología , Neoplasias Encefálicas/terapia , Neoplasias Encefálicas/fisiopatología , Neoplasias Encefálicas/patología , Animales
2.
J Biol Chem ; 300(8): 107595, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39032650

RESUMEN

The long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) is involved in a variety of human cancers. Two overlapping NEAT1 isoforms, NEAT1_1 and NEAT1_2, are produced through mutually exclusive alternative 3' end formation. Previous studies extensively investigated NEAT1 dysregulation in tumors, but often failed to achieve distinct quantification of the two NEAT1 isoforms. Moreover, molecular mechanisms governing the biogenesis of NEAT1 isoforms and the functional impacts of their dysregulation in tumorigenesis remain poorly understood. In this study, we employed an isoform-specific quantification assay and found differential dysregulation of NEAT1 isoforms in patient-derived glioblastoma multiforme cells. We further showed usage of the NEAT1 proximal polyadenylation site (PAS) is a critical mechanism that controls glioma NEAT1 isoform production. CRISPR-Cas9-mediated PAS deletion reduced NEAT1_1 and reciprocally increased NEAT1_2, which enhanced nuclear paraspeckle formation in human glioma cells. Moreover, the utilization of the NEAT1 PAS is facilitated by the RNA-binding protein quaking (QKI), which binds to the proximal QKI recognition elements. Functionally, we identified transcriptomic changes and altered biological pathways caused by NEAT1 isoform imbalance in glioma cells, including the pathway for the regulation of cell migration. Finally, we demonstrated the forced increase of NEAT1_2 upon NEAT1 PAS deletion is responsible for driving glioma cell migration and promoting the expression of genes implicated in the regulation of cell migration. Together, our studies uncovered a novel mechanism that regulates NEAT1 isoforms and their functional impacts on the glioma transcriptome, which affects pathological pathways of glioma, represented by migration.


Asunto(s)
Movimiento Celular , Glioma , ARN Largo no Codificante , Proteínas de Unión al ARN , Transcriptoma , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Glioma/metabolismo , Glioma/genética , Glioma/patología , Regulación Neoplásica de la Expresión Génica , Línea Celular Tumoral , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/genética , Poliadenilación
3.
Brain ; 144(1): 53-69, 2021 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-33300045

RESUMEN

Paediatric high-grade gliomas (HGGs) account for the most brain tumour-related deaths in children and have a median survival of 12-15 months. One promising avenue of research is the development of novel therapies targeting the properties of non-neoplastic cell-types within the tumour such as tumour associated macrophages (TAMs). TAMs are immunosuppressive and promote tumour malignancy in adult HGG; however, in paediatric medulloblastoma, TAMs exhibit anti-tumour properties. Much is known about TAMs in adult HGG, yet little is known about them in the paediatric setting. This raises the question of whether paediatric HGGs possess a distinct constituency of TAMs because of their unique genetic landscapes. Using human paediatric HGG tissue samples and murine models of paediatric HGG, we demonstrate diffuse midline gliomas possess a greater inflammatory gene expression profile compared to hemispheric paediatric HGGs. We also show despite possessing sparse T-cell infiltration, human paediatric HGGs possess high infiltration of IBA1+ TAMs. CD31, PDGFRß, and PDGFB all strongly correlate with IBA1+ TAM infiltration. To investigate the TAM population, we used the RCAS/tv-a system to recapitulate paediatric HGG in newborn immunocompetent mice. Tumours are induced in Nestin-positive brain cells by PDGFA or PDGFB overexpression with Cdkn2a or Tp53 co-mutations. Tumours driven by PDGFB have a significantly lower median survival compared to PDGFA-driven tumours and have increased TAM infiltration. NanoString and quantitative PCR analysis indicates PDGFB-driven tumours have a highly inflammatory microenvironment characterized by high chemokine expression. In vitro bone marrow-derived monocyte and microglial cultures demonstrate bone marrow-derived monocytes are most responsible for the production of inflammatory signals in the tumour microenvironment in response to PDGFB stimulation. Lastly, using knockout mice deficient for individual chemokines, we demonstrate the feasibility of reducing TAM infiltration and prolonging survival in both PDGFA and PDGFB-driven tumours. We identify CCL3 as a potential key chemokine in these processes in both humans and mice. Together, these studies provide evidence for the potent inflammatory effects PDGFB has in paediatric HGGs.


Asunto(s)
Neoplasias Encefálicas/inmunología , Encefalitis/inmunología , Proteínas Proto-Oncogénicas c-sis/inmunología , Macrófagos Asociados a Tumores/inmunología , Adolescente , Adulto , Animales , Neoplasias Encefálicas/genética , Células Cultivadas , Quimiocinas/genética , Niño , Preescolar , Encefalitis/genética , Femenino , Glioma , Humanos , Lactante , Recién Nacido , Masculino , Ratones Endogámicos C57BL , Transcriptoma , Adulto Joven
4.
Development ; 145(23)2018 12 04.
Artículo en Inglés | MEDLINE | ID: mdl-30327326

RESUMEN

Stem cells reside in specialized microenvironments, called niches, that regulate their development and the development of their progeny. However, the development and maintenance of niches are poorly understood. In the Drosophila brain, cortex glial cells provide a niche that promotes self-renewal and proliferation of neural stem cell-like cells (neuroblasts). In the central brain, neuroblasts and their progeny control post-embryonic morphogenesis of cortex glia through PDGF-like ligands, and this PDGFR receptor tyrosine kinase (RTK) signaling in cortex glia is required for expression of DE-cadherin, which sustains neuroblasts. Thus, through an RTK-dependent feed-forward loop, neuroblasts and their glial niche actively maintain each other. When the EGFR RTK is constitutively activated in cortex glia, they overexpress PDGF orthologs to stimulate autocrine PDGFR signaling, which uncouples their growth and survival from neuroblasts, and drives neoplastic glial transformation and elimination of neuroblasts. These results provide fundamental insights into glial development and niche regulation, and show that niche-neural stem cell feed-forward signaling becomes hijacked to drive neural tumorigenesis.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/embriología , Embrión no Mamífero/citología , Morfogénesis , Células-Madre Neurales/citología , Neuroglía/citología , Proteínas Tirosina Quinasas Receptoras/metabolismo , Transducción de Señal , Animales , Comunicación Autocrina , Encéfalo/crecimiento & desarrollo , Proliferación Celular , Supervivencia Celular , Drosophila melanogaster/enzimología , Embrión no Mamífero/enzimología , Pruebas Genéticas , Células-Madre Neurales/metabolismo , Neuroglía/metabolismo , Neuronas/citología , Neuronas/metabolismo
5.
Glia ; 68(10): 2148-2166, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32639068

RESUMEN

Glioblastoma (GBM) is the most aggressive primary brain tumor. In addition to being genetically heterogeneous, GBMs are also immunologically heterogeneous. However, whether the differences in immune microenvironment are driven by genetic driver mutation is unexplored. By leveraging the versatile RCAS/tv-a somatic gene transfer system, we establish a mouse model for Classical GBM by introducing EGFRvIII expression in Nestin-positive neural stem/progenitor cells in adult mice. Along with our previously published Nf1-silenced and PDGFB-overexpressing models, we investigate the immune microenvironments of the three models of human GBM subtypes by unbiased multiplex profiling. We demonstrate that both the quantity and composition of the microenvironmental myeloid cells are dictated by the genetic driver mutations, closely mimicking what was observed in human GBM subtypes. These myeloid cells express high levels of the immune checkpoint protein PD-L1; however, PD-L1 targeted therapies alone or in combination with irradiation are unable to increase the survival time of tumor-bearing mice regardless of the driver mutations, reflecting the outcomes of recent human trials. Together, these results highlight the critical utility of immunocompetent mouse models for preclinical studies of GBM, making these models indispensable tools for understanding the resistance mechanisms of immune checkpoint blockade in GBM and immune cell-targeting drug discovery.


Asunto(s)
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/inmunología , Glioblastoma/genética , Glioblastoma/inmunología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Mutación/fisiología , Animales , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Femenino , Glioblastoma/tratamiento farmacológico , Glioblastoma/patología , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Células Tumorales Cultivadas
6.
Adv Exp Med Biol ; 1167: 207-224, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31520357

RESUMEN

Glioblastoma multiforme (GBM) is the most common primary malignant adult brain tumor. Genomic amplifications, activating mutations, and overexpression of receptor tyrosine kinases (RTKs) such as EGFR, and genes in core RTK signaling transduction pathways such as PI3K are common in GBM. However, efforts to target these pathways have been largely unsuccessful in the clinic, and the median survival of GBM patients remains poor at 14-15 months. Therefore, to improve patient outcomes, there must be a concerted effort to elucidate the underlying biology involved in GBM tumorigenesis. Drosophila melanogaster has been a highly effective model for furthering our understanding of GBM tumorigenesis due to a number of experimental advantages it has over traditional mouse models. For example, there exists extensive cellular and genetic homology between humans and Drosophila, and 75% of genes associated with human disease have functional fly orthologs. To take advantage of these traits, we developed a Drosophila GBM model with constitutively active variants of EGFR and PI3K that effectively recapitulated key aspects of GBM disease. Researchers have utilized this model in forward genetic screens and have expanded on its functionality to make a number of important discoveries regarding requirements for key components in GBM tumorigenesis, including genes and pathways involved in extracellular matrix signaling, glycolytic metabolism, invasion/migration, stem cell fate and differentiation, and asymmetric cell division. Drosophila will continue to reveal novel biological pathways and mechanisms involved in gliomagenesis, and this knowledge may contribute to the development of effective treatment strategies to improve patient outcomes.


Asunto(s)
Neoplasias Encefálicas/patología , Drosophila melanogaster , Glioblastoma/patología , Adulto , Animales , Transformación Celular Neoplásica , Modelos Animales de Enfermedad , Humanos , Ratones , Transducción de Señal
7.
PLoS Genet ; 9(2): e1003253, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23459592

RESUMEN

Glioblastoma, the most common primary malignant brain tumor, is incurable with current therapies. Genetic and molecular analyses demonstrate that glioblastomas frequently display mutations that activate receptor tyrosine kinase (RTK) and Pi-3 kinase (PI3K) signaling pathways. In Drosophila melanogaster, activation of RTK and PI3K pathways in glial progenitor cells creates malignant neoplastic glial tumors that display many features of human glioblastoma. In both human and Drosophila, activation of the RTK and PI3K pathways stimulates Akt signaling along with other as-yet-unknown changes that drive oncogenesis. We used this Drosophila glioblastoma model to perform a kinome-wide genetic screen for new genes required for RTK- and PI3K-dependent neoplastic transformation. Human orthologs of novel kinases uncovered by these screens were functionally assessed in mammalian glioblastoma models and human tumors. Our results revealed that the atypical kinases RIOK1 and RIOK2 are overexpressed in glioblastoma cells in an Akt-dependent manner. Moreover, we found that overexpressed RIOK2 formed a complex with RIOK1, mTor, and mTor-complex-2 components, and that overexpressed RIOK2 upregulated Akt signaling and promoted tumorigenesis in murine astrocytes. Conversely, reduced expression of RIOK1 or RIOK2 disrupted Akt signaling and caused cell cycle exit, apoptosis, and chemosensitivity in glioblastoma cells by inducing p53 activity through the RpL11-dependent ribosomal stress checkpoint. These results imply that, in glioblastoma cells, constitutive Akt signaling drives RIO kinase overexpression, which creates a feedforward loop that promotes and maintains oncogenic Akt activity through stimulation of mTor signaling. Further study of the RIO kinases as well as other kinases identified in our Drosophila screen may reveal new insights into defects underlying glioblastoma and related cancers and may reveal new therapeutic opportunities for these cancers.


Asunto(s)
Transformación Celular Neoplásica , Glioblastoma , Complejos Multiproteicos , Proteína Oncogénica v-akt , Fosfatidilinositol 3-Quinasas , Serina-Treonina Quinasas TOR , Animales , Apoptosis/genética , Astrocitos/citología , Astrocitos/metabolismo , Proliferación Celular , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Regulación Neoplásica de la Expresión Génica , Genoma de los Insectos , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Diana Mecanicista del Complejo 2 de la Rapamicina , Ratones , Complejos Multiproteicos/genética , Complejos Multiproteicos/metabolismo , Neuroglía/metabolismo , Proteína Oncogénica v-akt/genética , Proteína Oncogénica v-akt/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo
8.
PLoS Genet ; 5(2): e1000374, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19214224

RESUMEN

Gliomas, the most common malignant tumors of the nervous system, frequently harbor mutations that activate the epidermal growth factor receptor (EGFR) and phosphatidylinositol-3 kinase (PI3K) signaling pathways. To investigate the genetic basis of this disease, we developed a glioma model in Drosophila. We found that constitutive coactivation of EGFR-Ras and PI3K pathways in Drosophila glia and glial precursors gives rise to neoplastic, invasive glial cells that create transplantable tumor-like growths, mimicking human glioma. Our model represents a robust organotypic and cell-type-specific Drosophila cancer model in which malignant cells are created by mutations in signature genes and pathways thought to be driving forces in a homologous human cancer. Genetic analyses demonstrated that EGFR and PI3K initiate malignant neoplastic transformation via a combinatorial genetic network composed primarily of other pathways commonly mutated or activated in human glioma, including the Tor, Myc, G1 Cyclins-Cdks, and Rb-E2F pathways. This network acts synergistically to coordinately stimulate cell cycle entry and progression, protein translation, and inappropriate cellular growth and migration. In particular, we found that the fly orthologs of CyclinE, Cdc25, and Myc are key rate-limiting genes required for glial neoplasia. Moreover, orthologs of Sin1, Rictor, and Cdk4 are genes required only for abnormal neoplastic glial proliferation but not for glial development. These and other genes within this network may represent important therapeutic targets in human glioma.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Receptores ErbB/metabolismo , Glioma/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas ras/metabolismo , Animales , Ciclo Celular , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Modelos Animales de Enfermedad , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Receptores ErbB/genética , Glioma/metabolismo , Glioma/patología , Humanos , Mutación , Neuroglía/citología , Neuroglía/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Transducción de Señal , Proteínas ras/genética
9.
STAR Protoc ; 3(3): 101609, 2022 09 16.
Artículo en Inglés | MEDLINE | ID: mdl-35990742

RESUMEN

This protocol describes a genetic model system we developed for glioblastoma (GBM) in Drosophila melanogaster, which can be used to explore the pathogenic phenotypic effects of mutated genetic pathways and to identify potential therapeutic targets for tumors with these mutations. We present genetic schemes and experimental steps needed to create neoplastic glial brain tumors in larval Drosophila. We also provide steps to manipulate genes in this model and to perform brain fixation, immunostaining, and imaging of neoplastic larval brains. For complete details on the use and execution of this protocol, please refer to Read et al., (2009).


Asunto(s)
Glioblastoma , Glioma , Animales , Encéfalo/diagnóstico por imagen , Drosophila melanogaster/genética , Glioblastoma/genética , Glioma/patología , Humanos , Larva/genética
10.
Glia ; 59(9): 1364-76, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21538561

RESUMEN

Glioblastomas (GBM), the most common primary brain tumors, infiltrate the brain, grow rapidly, and are refractory to current therapies. Signature genetic lesions in glioblastomas include mutation of the epidermal growth factor receptor tyrosine kinase (EGFR) receptor tyrosine kinase and activating mutations in components of the PI-3 kinase (PI3K) pathway. Despite years of study, how these pathways specifically regulate glial pathogenesis is unclear. To address the genetic and cellular origins of this disease, a novel Drosophila GBM model has been developed in which glial progenitor cells give rise to proliferative and invasive neoplastic cells that create transplantable tumors in response to constitutive co-activation of the EGFR-Ras and PI3K pathways. Standing with a rich literature demonstrating the direct relevance of Drosophila to studies on human cancer, neurological disease, and neurodevelopment, this model represents a robust cell-type specific Drosophila neurological disease model in which malignant cells are created by mutations in genetic pathways thought to be driving forces in a homologous human disease. Using lineage analysis and cell-type specific markers, neoplastic glial cells were found to originate from committed glial progenitor cells, rather than from multipotent neuroblasts. Genetic analyses demonstrated that EGFR-Ras and PI3K induce fly glial neoplasia through activation of a combinatorial genetic network composed, in part, of other genetic pathways also commonly mutated in human glioblastomas. In the future, large-scale forward genetic screens with this model may reveal new insights into the origins and treatments of human glioblastoma.


Asunto(s)
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Drosophila melanogaster/fisiología , Animales , Biomarcadores de Tumor , Sistema Nervioso Central/química , Sistema Nervioso Central/fisiología , Modelos Animales de Enfermedad , Glioblastoma/patología , Glioma/patología , Humanos , Neuroglía/patología , Neuroglía/fisiología
11.
Clin Cancer Res ; 27(5): 1553-1569, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33172899

RESUMEN

PURPOSE: Glioblastomas (GBMs), neoplasms derived from glia and neuroglial progenitor cells, are the most common and lethal malignant primary brain tumors diagnosed in adults, with a median survival of 14 months. GBM tumorigenicity is often driven by genetic aberrations in receptor tyrosine kinases, such as amplification and mutation of EGFR. EXPERIMENTAL DESIGN: Using a Drosophila glioma model and human patient-derived GBM stem cells and xenograft models, we genetically and pharmacologically tested whether the YAP and TAZ transcription coactivators, effectors of the Hippo pathway that promote gene expression via TEA domain (TEAD) cofactors, are key drivers of GBM tumorigenicity downstream of oncogenic EGFR signaling. RESULTS: YAP and TAZ are highly expressed in EGFR-amplified/mutant human GBMs, and their knockdown in EGFR-amplified/mutant GBM cells inhibited proliferation and elicited apoptosis. Our results indicate that YAP/TAZ-TEAD directly regulates transcription of SOX2, C-MYC, and EGFR itself to create a feedforward loop to drive survival and proliferation of human GBM cells. Moreover, the benzoporphyrin derivative verteporfin, a disruptor of YAP/TAZ-TEAD-mediated transcription, preferentially induced apoptosis of cultured patient-derived EGFR-amplified/mutant GBM cells, suppressed expression of YAP/TAZ transcriptional targets, including EGFR, and conferred significant survival benefit in an orthotopic xenograft GBM model. Our efforts led us to design and initiate a phase 0 clinical trial of Visudyne, an FDA-approved liposomal formulation of verteporfin, where we used intraoperative fluorescence to observe verteporfin uptake into tumor cells in GBM tumors in human patients. CONCLUSIONS: Together, our data suggest that verteporfin is a promising therapeutic agent for EGFR-amplified and -mutant GBM.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Proteínas de Ciclo Celular/antagonistas & inhibidores , Regulación Neoplásica de la Expresión Génica , Glioblastoma/tratamiento farmacológico , Mutación , Factores de Transcripción/antagonistas & inhibidores , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ/antagonistas & inhibidores , Verteporfina/farmacología , Animales , Apoptosis , Biomarcadores de Tumor/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proliferación Celular , Drosophila melanogaster , Receptores ErbB/genética , Femenino , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Células Madre Neoplásicas , Fármacos Fotosensibilizantes/farmacología , Pronóstico , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ/genética , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
12.
Pharmaceuticals (Basel) ; 14(2)2021 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-33525329

RESUMEN

Glioblastoma multiforme (GBM) is a highly malignant primary brain tumor. The current standard of care for GBM is the Stupp protocol which includes surgical resection, followed by radiotherapy concomitant with the DNA alkylator temozolomide; however, survival under this treatment regimen is an abysmal 12-18 months. New and emerging treatments include the application of a physical device, non-invasive 'tumor treating fields' (TTFs), including its concomitant use with standard of care; and varied vaccines and immunotherapeutics being trialed. Some of these approaches have extended life by a few months over standard of care, but in some cases are only available for a minority of GBM patients. Extensive activity is also underway to repurpose and reposition therapeutics for GBM, either alone or in combination with the standard of care. In this review, we present select molecules that target different pathways and are at various stages of clinical translation as case studies to illustrate the rationale for their repurposing-repositioning and potential clinical use.

13.
Sci Rep ; 9(1): 13611, 2019 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-31541170

RESUMEN

Medulloblastoma is a malignant pediatric tumor that arises from neural progenitors in the cerebellum. Despite a five-year survival rate of ~70%, nearly all patients incur adverse side effects from current treatment strategies that drastically impact quality of life. Roughly one-third of medulloblastoma are driven by aberrant activation of the Sonic Hedgehog (SHH) signaling pathway. However, the scarcity of genetic mutations in medulloblastoma has led to investigation of other mechanisms contributing to cancer pathogenicity including epigenetic regulation of gene expression. Here, we show that Helicase, Lymphoid Specific (HELLS), a chromatin remodeler with epigenetic functions including DNA methylation and histone modification, is induced by Sonic Hedgehog (SHH) in SHH-dependent cerebellar progenitor cells and the developing murine cerebella. HELLS is also up-regulated in mouse and human SHH medulloblastoma. Others have shown that HELLS activity generally results in a repressive chromatin state. Our results demonstrate that increased expression of HELLS in our experimental systems is regulated by the oncogenic transcriptional regulator YAP1 downstream of Smoothened, the positive transducer of SHH signaling. Elucidation of HELLS as one of the downstream effectors of the SHH pathway may lead to novel targets for precision therapeutics with the promise of better outcomes for SHH medulloblastoma patients.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas de Ciclo Celular/metabolismo , ADN Helicasas/genética , Meduloblastoma/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Adulto , Animales , Proteínas de Ciclo Celular/genética , Células Cultivadas , Neoplasias Cerebelosas/patología , Cerebelo/metabolismo , Niño , Cromatina/metabolismo , Ensamble y Desensamble de Cromatina/genética , ADN Helicasas/metabolismo , Epigénesis Genética/genética , Femenino , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/fisiología , Humanos , Masculino , Meduloblastoma/metabolismo , Ratones , Células-Madre Neurales/metabolismo , Neuronas/metabolismo , Calidad de Vida , Transducción de Señal , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Activación Transcripcional , Regulación hacia Arriba , Proteínas Señalizadoras YAP
14.
Cancer Res ; 79(6): 1085-1097, 2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30530503

RESUMEN

Glioblastoma (GBM) and lower grade gliomas (LGG) are the most common primary malignant brain tumors and are resistant to current therapies. Genomic analyses reveal that signature genetic lesions in GBM and LGG include copy gain and amplification of chromosome 7, amplification, mutation, and overexpression of receptor tyrosine kinases (RTK) such as EGFR, and activating mutations in components of the PI3K pathway. In Drosophila melanogaster, constitutive co-activation of RTK and PI3K signaling in glial progenitor cells recapitulates key features of human gliomas. Here we use this Drosophila glioma model to identify death-associated protein kinase (Drak), a cytoplasmic serine/threonine kinase orthologous to the human kinase STK17A, as a downstream effector of EGFR and PI3K signaling pathways. Drak was necessary for glial neoplasia, but not for normal glial proliferation and development, and Drak cooperated with EGFR to promote glial cell transformation. Drak phosphorylated Sqh, the Drosophila ortholog of nonmuscle myosin regulatory light chain (MRLC), which was necessary for transformation. Moreover, Anillin, which is a binding partner of phosphorylated Sqh, was upregulated in a Drak-dependent manner in mitotic cells and colocalized with phosphorylated Sqh in neoplastic cells undergoing mitosis and cytokinesis, consistent with their known roles in nonmuscle myosin-dependent cytokinesis. These functional relationships were conserved in human GBM. Our results indicate that Drak/STK17A, its substrate Sqh/MRLC, and the effector Anillin/ANLN regulate mitosis and cytokinesis in gliomas. This pathway may provide a new therapeutic target for gliomas.Significance: These findings reveal new insights into differential regulation of cell proliferation in malignant brain tumors, which will have a broader impact on research regarding mechanisms of oncogene cooperation and dependencies in cancer.See related commentary by Lathia, p. 1036.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Biomarcadores de Tumor/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Regulación Neoplásica de la Expresión Génica , Glioblastoma/patología , Cadenas Ligeras de Miosina/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Apoptosis , Proteínas Reguladoras de la Apoptosis/genética , Biomarcadores de Tumor/genética , Proliferación Celular , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crecimiento & desarrollo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Mitosis , Cadenas Ligeras de Miosina/genética , Fosforilación , Pronóstico , Proteínas Serina-Treonina Quinasas/genética , Transducción de Señal , Tasa de Supervivencia , Células Tumorales Cultivadas
15.
Mol Cell Biol ; 24(15): 6676-89, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15254235

RESUMEN

Src family kinases regulate multiple cellular processes including proliferation and oncogenesis. C-terminal Src kinase (Csk) encodes a critical negative regulator of Src family kinases. We demonstrate that the Drosophila melanogaster Csk ortholog, dCsk, functions as a tumor suppressor: dCsk mutants display organ overgrowth and excess cellular proliferation. Genetic analysis indicates that the dCsk(-/-) overgrowth phenotype results from activation of Src, Jun kinase, and STAT signal transduction pathways. In particular, blockade of STAT function in dCsk mutants severely reduced Src-dependent overgrowth and activated apoptosis of mutant tissue. Our data provide in vivo evidence that Src activity requires JNK and STAT function.


Asunto(s)
Proteínas Quinasas Activadas por Mitógenos/química , Proteínas Tirosina Quinasas/química , Transducción de Señal , Familia-src Quinasas/metabolismo , Animales , Proteína Tirosina Quinasa CSK , Ciclo Celular , División Celular , Proteínas de Unión al ADN/genética , Drosophila , Proteínas de Drosophila , Etiquetas de Secuencia Expresada , Citometría de Flujo , Genotipo , Inmunohistoquímica , Proteínas Quinasas JNK Activadas por Mitógenos , Larva/metabolismo , Microscopía Electrónica de Rastreo , Modelos Biológicos , Modelos Genéticos , Mutación , Fenotipo , Proteínas Tirosina Quinasas/metabolismo , Factor de Transcripción STAT3 , Factores de Tiempo , Transactivadores/genética
17.
Genetics ; 171(3): 1057-81, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15965261

RESUMEN

Dominant mutations in the Ret receptor tyrosine kinase lead to the familial cancer syndrome multiple endocrine neoplasia type 2 (MEN2). Mammalian tissue culture studies suggest that RetMEN2 mutations significantly alter Ret-signaling properties, but the precise mechanisms by which RetMEN2 promotes tumorigenesis remain poorly understood. To determine the signal transduction pathways required for RetMEN2 activity, we analyzed analogous mutations in the Drosophila Ret ortholog dRet. Overexpressed dRetMEN2 isoforms targeted to the developing retina led to aberrant cell proliferation, inappropriate cell fate specification, and excessive Ras pathway activation. Genetic analysis indicated that dRetMEN2 acts through the Ras-ERK, Src, and Jun kinase pathways. A genetic screen for mutations that dominantly suppress or enhance dRetMEN2 phenotypes identified new genes that are required for the phenotypic outcomes of dRetMEN2 activity. Finally, we identified human orthologs for many of these genes and examined their status in human tumors. Two of these loci showed loss of heterozygosity (LOH) within both sporadic and MEN2-associated pheochromocytomas, suggesting that they may contribute to Ret-dependent oncogenesis.


Asunto(s)
Modelos Animales de Enfermedad , Drosophila/genética , Neoplasia Endocrina Múltiple Tipo 2a/genética , Secuencia de Aminoácidos , Animales , Drosophila/crecimiento & desarrollo , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/genética , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Datos de Secuencia Molecular , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogénicas c-ret/genética , Proteínas Proto-Oncogénicas c-ret/metabolismo , Proteínas Proto-Oncogénicas pp60(c-src)/genética , Proteínas Proto-Oncogénicas pp60(c-src)/metabolismo , Retina/crecimiento & desarrollo , Retina/metabolismo , Proteínas ras/genética , Proteínas ras/metabolismo
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