RESUMEN
GPR133 (ADGRD1) is an adhesion G-protein-coupled receptor that signals through Gαs/cyclic AMP (cAMP) and is required for the growth of glioblastoma (GBM), an aggressive brain malignancy. The regulation of GPR133 signaling is incompletely understood. Here, we use proximity biotinylation proteomics to identify ESYT1, a Ca2+-dependent mediator of endoplasmic reticulum-plasma membrane bridge formation, as an intracellular interactor of GPR133. ESYT1 knockdown or knockout increases GPR133 signaling, while its overexpression has the opposite effect, without altering GPR133 levels in the plasma membrane. The GPR133-ESYT1 interaction requires the Ca2+-sensing C2C domain of ESYT1. Thapsigargin-mediated increases in cytosolic Ca2+ relieve signaling-suppressive effects of ESYT1 by promoting ESYT1-GPR133 dissociation. ESYT1 knockdown or knockout in GBM slows tumor growth, suggesting tumorigenic functions of ESYT1. Our findings demonstrate a mechanism for the modulation of GPR133 signaling by increased cytosolic Ca2+, which reduces the signaling-suppressive interaction between GPR133 and ESYT1 to raise cAMP levels.
Asunto(s)
Calcio , Glioblastoma , Receptores Acoplados a Proteínas G , Transducción de Señal , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Humanos , Animales , Calcio/metabolismo , Glioblastoma/metabolismo , Glioblastoma/patología , Glioblastoma/genética , Ratones , AMP Cíclico/metabolismo , Línea Celular Tumoral , Células HEK293 , Unión Proteica , Ratones Desnudos , Proteínas OncogénicasRESUMEN
Glioblastoma (GBM) is the most common and aggressive primary brain malignancy. Adhesion G protein-coupled receptors (aGPCRs) have attracted interest for their potential as treatment targets. Here, we show that CD97 (ADGRE5) is the most promising aGPCR target in GBM, by virtue of its de novo expression compared to healthy brain tissue. CD97 knockdown or knockout significantly reduces the tumor initiation capacity of patient-derived GBM cultures (PDGCs) in vitro and in vivo. We find that CD97 promotes glycolytic metabolism via the mitogen-activated protein kinase (MAPK) pathway, which depends on phosphorylation of its C terminus and recruitment of ß-arrestin. We also demonstrate that THY1/CD90 is a likely CD97 ligand in GBM. Lastly, we show that an anti-CD97 antibody-drug conjugate selectively kills tumor cells in vitro. Our studies identify CD97 as a regulator of tumor metabolism, elucidate mechanisms of receptor activation and signaling, and provide strong scientific rationale for developing biologics to target it therapeutically in GBM.
Asunto(s)
Glioblastoma , Humanos , Glioblastoma/patología , Fosforilación , Receptores Acoplados a Proteínas G/metabolismo , Transducción de SeñalRESUMEN
BACKGROUND: Intracranial solitary fibrous tumors (SFTs), formerly hemangiopericytomas (HPCs), are rare, aggressive dural-based mesenchymal tumors. While adjuvant radiation therapy has been suggested to improve local tumor control (LTC), especially after subtotal resection, the role of postoperative stereotactic radiosurgery (SRS) and the optimal SRS dosing strategy remain poorly defined. METHODS: PubMed, EMBASE, and Web of Science were systematically searched according to PRISMA guidelines for studies describing postoperative SRS for intracranial SFTs. The search strategy was defined in the authors' PROSPERO protocol (CRD42023454258). RESULTS: 15 studies were included describing 293 patients harboring 476 intracranial residual or recurrent SFTs treated with postoperative SRS. At a mean follow-up of 21-77 months, LTC rate after SRS was 46.4-93% with a mean margin SRS dose of 13.5-21.7 Gy, mean maximum dose of 27-39.6 Gy, and mean isodose at the 42.5-77% line. In pooled analysis of individual tumor outcomes, 18.7% of SFTs demonstrated a complete SRS response, 31.7% had a partial response, 18.9% remained stable (overall LTC rate of 69.3%), and 30.7% progressed. When studies were stratified by margin dose, a mean margin dose > 15 Gy showed an improvement in LTC rate (74.7% versus 65.7%). CONCLUSIONS: SRS is a safe and effective treatment for intracranial SFTs. In the setting of measurable disease, our pooled data suggests a potential dose response of improving LTC with increasing SRS margin dose. Our improved understanding of the aggressive biology of SFTs and the tolerated adjuvant SRS parameters supports potentially earlier use of SRS in the postoperative treatment paradigm for intracranial SFTs.
Asunto(s)
Radiocirugia , Síndrome de Trombocitopenia Febril Grave , Tumores Fibrosos Solitarios , Humanos , Radiocirugia/métodos , Estudios de Seguimiento , Estudios Retrospectivos , Resultado del Tratamiento , Tumores Fibrosos Solitarios/radioterapia , Tumores Fibrosos Solitarios/cirugíaRESUMEN
Mutations in IDH1 and IDH2 drive the development of gliomas. These genetic alterations promote tumor cell renewal, disrupt differentiation states, and induce stem-like properties. Understanding how this phenotypic reprogramming occurs remains an area of high interest in glioma research. Previously, we showed that IDH mutation results in the development of a CD24-positive cell population in gliomas. Here, we demonstrate that this CD24-positive population possesses striking stem-like properties at the molecular and phenotypic levels. We found that CD24 expression is associated with stem-like features in IDH-mutant tumors, a patient-derived gliomasphere model, and a neural stem cell model of IDH1-mutant glioma. In orthotopic models, CD24-positive cells display enhanced tumor initiating potency compared to CD24-negative cells. Furthermore, CD24 knockdown results in changes in cell viability, proliferation rate, and gene expression that closely resemble a CD24-negative phenotype. Our data demonstrate that induction of a CD24-positive population is one mechanism by which IDH-mutant tumors acquire stem-like properties. These findings have significant implications for our understanding of the molecular underpinnings of IDH-mutant gliomas.
Asunto(s)
Neoplasias Encefálicas , Glioma , Isocitrato Deshidrogenasa , Células Madre Neoplásicas , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Antígeno CD24/genética , Antígeno CD24/metabolismo , Glioma/genética , Glioma/metabolismo , Glioma/patología , Humanos , Isocitrato Deshidrogenasa/genética , Isocitrato Deshidrogenasa/metabolismo , Mutación , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , FenotipoRESUMEN
Mutations in IDH1 and IDH2 (encoding isocitrate dehydrogenase 1 and 2) drive the development of gliomas and other human malignancies. Mutant IDH1 induces epigenetic changes that promote tumorigenesis, but the scale and reversibility of these changes are unknown. Here, using human astrocyte and glioma tumorsphere systems, we generate a large-scale atlas of mutant-IDH1-induced epigenomic reprogramming. We characterize the reversibility of the alterations in DNA methylation, the histone landscape, and transcriptional reprogramming that occur following IDH1 mutation. We discover genome-wide coordinate changes in the localization and intensity of multiple histone marks and chromatin states. Mutant IDH1 establishes a CD24+ population with a proliferative advantage and stem-like transcriptional features. Strikingly, prolonged exposure to mutant IDH1 results in irreversible genomic and epigenetic alterations. Together, these observations provide unprecedented high-resolution molecular portraits of mutant-IDH1-dependent epigenomic reprogramming. These findings have substantial implications for understanding of mutant IDH function and for optimizing therapeutic approaches to targeting IDH-mutant tumors.
Asunto(s)
Cromatina/metabolismo , Epigénesis Genética , Isocitrato Deshidrogenasa/genética , Mutación , Transcriptoma , Animales , Astrocitos/metabolismo , Células Cultivadas , Metilación de ADN , Retrovirus Endógenos , Femenino , Perfilación de la Expresión Génica , Inestabilidad Genómica , Glioma/genética , Glioma/metabolismo , Código de Histonas , Humanos , Isocitrato Deshidrogenasa/metabolismo , Ratones Endogámicos NOD , Ratones SCID , FenotipoRESUMEN
Purpose: While the tumor microenvironment has been known to play an integral role in tumor progression, the function of nonresident bone marrow-derived cells (BMDC) remains to be determined in neurologic tumors. Here we identified the contribution of BMDC recruitment in mediating malignant transformation from low- to high-grade gliomas.Experimental Design: We analyzed human blood and tumor samples from patients with low- and high-grade gliomas. A spontaneous platelet-derived growth factor (PDGF) murine glioma model (RCAS) was utilized to recapitulate human disease progression. Levels of CD11b+/GR1+ BMDCs were analyzed at discrete stages of tumor progression. Using bone marrow transplantation, we determined the unique influence of BMDCs in the transition from low- to high-grade glioma. The functional role of these BMDCs was then examined using a JAK 1/2 inhibitor (AZD1480).Results: CD11b+ myeloid cells were significantly increased during tumor progression in peripheral blood and tumors of glioma patients. Increases in CD11b+/GR1+ cells were observed in murine peripheral blood, bone marrow, and tumors during low-grade to high-grade transformation. Transient blockade of CD11b+ cell expansion using a JAK 1/2 Inhibitor (AZD1480) impaired mobilization of these cells and was associated with a reduction in tumor volume, maintenance of a low-grade tumor phenotype, and prolongation in survival.Conclusions: We demonstrate that impaired recruitment of CD11b+ myeloid cells with a JAK1/2 inhibitor inhibits glioma progression in vivo and prolongs survival in a murine glioma model. Clin Cancer Res; 23(12); 3109-19. ©2016 AACR.
Asunto(s)
Astrocitoma/tratamiento farmacológico , Janus Quinasa 1/genética , Neovascularización Patológica/tratamiento farmacológico , Pirazoles/administración & dosificación , Pirimidinas/administración & dosificación , Animales , Astrocitoma/sangre , Astrocitoma/genética , Astrocitoma/patología , Antígeno CD11b/antagonistas & inhibidores , Antígeno CD11b/inmunología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Humanos , Janus Quinasa 1/antagonistas & inhibidores , Masculino , Ratones , Células Mieloides/efectos de los fármacos , Células Mieloides/patología , Neovascularización Patológica/patología , Microambiente Tumoral/efectos de los fármacosRESUMEN
Ewing sarcoma cells depend on the EWS-FLI1 fusion transcription factor for cell survival. Using an assay of EWS-FLI1 activity and genome-wide RNAi screening, we have identified proteins required for the processing of the EWS-FLI1 pre-mRNA. We show that Ewing sarcoma cells harboring a genomic breakpoint that retains exon 8 of EWSR1 require the RNA-binding protein HNRNPH1 to express in-frame EWS-FLI1. We also demonstrate the sensitivity of EWS-FLI1 fusion transcripts to the loss of function of the U2 snRNP component, SF3B1. Disrupted splicing of the EWS-FLI1 transcript alters EWS-FLI1 protein expression and EWS-FLI1-driven expression. Our results show that the processing of the EWS-FLI1 fusion RNA is a potentially targetable vulnerability in Ewing sarcoma cells.
Asunto(s)
Proteínas de Fusión Oncogénica/metabolismo , Proteína Proto-Oncogénica c-fli-1/metabolismo , Proteína EWS de Unión a ARN/metabolismo , Secuencia de Bases , Sitios de Unión , Proteínas de Unión a Calmodulina/antagonistas & inhibidores , Proteínas de Unión a Calmodulina/genética , Proteínas de Unión a Calmodulina/metabolismo , Línea Celular Tumoral , Supervivencia Celular , Exones , Regulación Neoplásica de la Expresión Génica , Ribonucleoproteína Heterogénea-Nuclear Grupo F-H/antagonistas & inhibidores , Ribonucleoproteína Heterogénea-Nuclear Grupo F-H/genética , Ribonucleoproteína Heterogénea-Nuclear Grupo F-H/metabolismo , Humanos , Proteínas de Microfilamentos/antagonistas & inhibidores , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Proteínas de Fusión Oncogénica/antagonistas & inhibidores , Proteínas de Fusión Oncogénica/genética , Fosfoproteínas/antagonistas & inhibidores , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteína Proto-Oncogénica c-fli-1/antagonistas & inhibidores , Proteína Proto-Oncogénica c-fli-1/genética , Interferencia de ARN , Precursores del ARN/metabolismo , Empalme del ARN , Factores de Empalme de ARN , ARN Interferente Pequeño/metabolismo , Proteína EWS de Unión a ARN/antagonistas & inhibidores , Proteína EWS de Unión a ARN/genética , Proteínas de Unión al ARN/antagonistas & inhibidores , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Receptores Citoplasmáticos y Nucleares/antagonistas & inhibidores , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Ribonucleoproteína Nuclear Pequeña U2/antagonistas & inhibidores , Ribonucleoproteína Nuclear Pequeña U2/genética , Ribonucleoproteína Nuclear Pequeña U2/metabolismo , Sarcoma de Ewing/patología , Transactivadores , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
LRRK2, a gene relevant to Parkinson's disease, encodes a scaffolding protein with both GTPase and kinase activities. LRRK2 protein is itself phosphorylated and therefore is subject to regulation by cell signalling; however, the kinase(s) responsible for this event have not been definitively identified. Here using an unbiased siRNA kinome screen, we identify and validate casein kinase 1α (CK1α) as being responsible for LRRK2 phosphorylation, including in the adult mouse striatum. We further show that LRRK2 recruitment to TGN46-positive Golgi-derived vesicles is modulated by constitutive LRRK2 phosphorylation by CK1α. These effects are mediated by differential protein interactions of LRRK2 with a guanine nucleotide exchange factor, ARHGEF7. These pathways are therefore likely involved in the physiological maintenance of the Golgi in cells, which may play a role in the pathogenesis of Parkinson's disease.