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Tumor adaptation or selection is thought to underlie therapy resistance in glioma. To investigate longitudinal epigenetic evolution of gliomas in response to therapeutic pressure, we performed an epigenomic analysis of 132 matched initial and recurrent tumors from patients with IDH-wildtype (IDHwt) and IDH-mutant (IDHmut) glioma. IDHwt gliomas showed a stable epigenome over time with relatively low levels of global methylation. The epigenome of IDHmut gliomas showed initial high levels of genome-wide DNA methylation that was progressively reduced to levels similar to those of IDHwt tumors. Integration of epigenomics, gene expression, and functional genomics identified HOXD13 as a master regulator of IDHmut astrocytoma evolution. Furthermore, relapse of IDHmut tumors was accompanied by histologic progression that was associated with survival, as validated in an independent cohort. Finally, the initial cell composition of the tumor microenvironment varied between IDHwt and IDHmut tumors and changed differentially following treatment, suggesting increased neoangiogenesis and T-cell infiltration upon treatment of IDHmut gliomas. This study provides one of the largest cohorts of paired longitudinal glioma samples with epigenomic, transcriptomic, and genomic profiling and suggests that treatment of IDHmut glioma is associated with epigenomic evolution toward an IDHwt-like phenotype. SIGNIFICANCE: Standard treatments are related to loss of DNA methylation in IDHmut glioma, resulting in epigenetic activation of genes associated with tumor progression and alterations in the microenvironment that resemble treatment-naïve IDHwt glioma.
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Neoplasias Encefálicas , Glioma , Isocitrato Deshidrogenasa , Humanos , Neoplasias Encefálicas/patología , Epigénesis Genética , Epigenómica , Glioma/patología , Isocitrato Deshidrogenasa/genética , Isocitrato Deshidrogenasa/metabolismo , Mutación , Recurrencia Local de Neoplasia/genética , Microambiente TumoralRESUMEN
Glioblastoma (GBM) is the most common and aggressive primary brain tumor. GBM contains a small subpopulation of glioma stem cells (GSCs) that are implicated in treatment resistance, tumor infiltration, and recurrence, and are thereby considered important therapeutic targets. Recent clinical studies have suggested that the choice of general anesthetic (GA), particularly propofol, during tumor resection, affects subsequent tumor response to treatments and patient prognosis. In this study, we investigated the molecular mechanisms underlying propofol's anti-tumor effects on GSCs and their interaction with microglia cells. Propofol exerted a dose-dependent inhibitory effect on the self-renewal, expression of mesenchymal markers, and migration of GSCs and sensitized them to both temozolomide (TMZ) and radiation. At higher concentrations, propofol induced a large degree of cell death, as demonstrated using microfluid chip technology. Propofol increased the expression of the lncRNA BDNF-AS, which acts as a tumor suppressor in GBM, and silencing of this lncRNA partially abrogated propofol's effects. Propofol also inhibited the pro-tumorigenic GSC-microglia crosstalk via extracellular vesicles (EVs) and delivery of BDNF-AS. In conclusion, propofol exerted anti-tumor effects on GSCs, sensitized these cells to radiation and TMZ, and inhibited their pro-tumorigenic interactions with microglia via transfer of BDNF-AS by EVs.
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Neoplasias Encefálicas , Vesículas Extracelulares , Glioblastoma , Glioma , Propofol , ARN Largo no Codificante , Humanos , Neoplasias Encefálicas/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Vesículas Extracelulares/metabolismo , Glioblastoma/metabolismo , Glioma/metabolismo , Microglía/metabolismo , Células Madre Neoplásicas/patología , Propofol/farmacología , ARN Largo no Codificante/genética , Temozolomida/farmacologíaRESUMEN
Background: There is a compelling evidence from animal models that early exposure to clinically relevant general anesthetics (GAs) interferes with brain development, resulting in long-lasting cognitive impairments. Human studies have been inconclusive and are challenging due to numerous confounding factors. Here, we employed primary human neural cells to analyze ketamine neurotoxic effects focusing on the role of glial cells and their activation state. We also explored the roles of astrocyte-derived extracellular vesicles (EVs) and different components of the brain-derived neurotrophic factor (BDNF) pathway. Methods: Ketamine effects on cell death were analyzed using live/dead assay, caspase 3 activity and PARP-1 cleavage. Astrocytic and microglial cell differentiation was determined using RT-PCR, ELISA and phagocytosis assay. The impact of the neuron-glial cell interactions in the neurotoxic effects of ketamine was analyzed using transwell cultures. In addition, the role of isolated and secreted EVs in this cross-talk were studied. The expression and function of different components of the BDNF pathway were analyzed using ELISA, RT-PCR and gene silencing. Results: Ketamine induced neuronal and oligodendrocytic cell apoptosis and promoted pro-inflammatory astrocyte (A1) and microglia (M1) phenotypes. Astrocytes and microglia enhanced the neurotoxic effects of ketamine on neuronal cells, whereas neurons increased oligodendrocyte cell death. Ketamine modulated different components in the BDNF pathway: decreasing BDNF secretion in neurons and astrocytes while increasing the expression of p75 in neurons and that of BDNF-AS and pro-BDNF secretion in both neurons and astrocytes. We demonstrated an important role of EVs secreted by ketamine-treated astrocytes in neuronal cell death and a role for EV-associated BDNF-AS in this effect. Conclusions: Ketamine exerted a neurotoxic effect on neural cells by impacting both neuronal and non-neuronal cells. The BDNF pathway and astrocyte-derived EVs represent important mediators of ketamine effects. These results contribute to a better understanding of ketamine neurotoxic effects in humans and to the development of potential approaches to decrease its neurodevelopmental impact.
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Inactivating mutations in the Methyl-CpG Binding Protein 2 (MECP2) gene are the main cause of Rett syndrome (RTT). Despite extensive research into MECP2 function, no treatments for RTT are currently available. Here, we used an evolutionary genomics approach to construct an unbiased MECP2 gene network, using 1028 eukaryotic genomes to prioritize proteins with strong co-evolutionary signatures with MECP2. Focusing on proteins targeted by FDA-approved drugs led to three promising targets, two of which were previously linked to MECP2 function (IRAK, KEAP1) and one that was not (EPOR). The drugs targeting these three proteins (Pacritinib, DMF, and EPO) were able to rescue different phenotypes of MECP2 inactivation in cultured human neural cell types, and appeared to converge on Nuclear Factor Kappa B (NF-κB) signaling in inflammation. This study highlights the potential of comparative genomics to accelerate drug discovery, and yields potential new avenues for the treatment of RTT.
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Proteína 2 de Unión a Metil-CpG/uso terapéutico , Síndrome de Rett/terapia , Genómica , Humanos , Síndrome de Rett/genéticaRESUMEN
[This corrects the article DOI: 10.18632/oncotarget.15991.].
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Glioblastoma (GBM) is a highly aggressive tumor with poor prognosis. A small subpopulation of glioma stem cells (GSCs) has been implicated in radiation resistance and tumor recurrence. In this study we analyzed the expression of miRNAs associated with the functions of GSCs using miRNA microarray analysis of these cells compared with human neural stem cells. These analyses identified gene clusters associated with glioma cell invasiveness, axonal guidance, and TGF-ß signaling. miR-504 was significantly downregulated in GSCs compared with NSCs, its expression was lower in GBM compared with normal brain specimens and further decreased in the mesenchymal glioma subtype. Overexpression of miR-504 in GSCs inhibited their self-renewal, migration and the expression of mesenchymal markers. The inhibitory effect of miR-504 was mediated by targeting Grb10 expression which acts as an oncogene in GSCs and GBM. Overexpression of exogenous miR-504 resulted also in its delivery to cocultured microglia by GSC-secreted extracellular vesicles (EVs) and in the abrogation of the GSC-induced polarization of microglia to M2 subtype. Finally, miR-504 overexpression prolonged the survival of mice harboring GSC-derived xenografts and decreased tumor growth. In summary, we identified miRNAs and potential target networks that play a role in the stemness and mesenchymal transition of GSCs and the miR-504/Grb10 pathway as an important regulator of this process. Overexpression of miR-504 exerted antitumor effects in GSCs as well as bystander effects on the polarization of microglia via delivery by EVs.
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Neoplasias Encefálicas/genética , Vesículas Extracelulares/fisiología , Glioblastoma/genética , MicroARNs/fisiología , Microglía/citología , Células Madre Neoplásicas/citología , Animales , Neoplasias Encefálicas/metabolismo , Proteína Adaptadora GRB10/fisiología , Regulación Neoplásica de la Expresión Génica , Glioblastoma/metabolismo , Humanos , Ratones , Ratones Desnudos , Análisis por Micromatrices , Células-Madre Neurales/citología , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
OBJECTIVES: To determine if patients with coronavirus disease 2019 had a greater number of unplanned extubations resulting in reintubations than in patients without coronavirus disease 2019. DESIGN: Retrospective cohort study comparing the frequency of unplanned extubations resulting in reintubations in a group of coronavirus disease 2019 patients to a historical (noncoronavirus disease 2019) control group. SETTING: This study was conducted at Henry Ford Hospital, an academic medical center in Detroit, MI. The historical noncoronavirus disease 2019 patients were treated in the 68 bed medical ICU. The coronavirus disease 2019 patients were treated in the coronavirus disease ICU, which included the 68 medical ICU beds, 18 neuro-ICU beds, 32 surgical ICU beds, and 40 cardiovascular ICU beds, as the medical ICU was expanded to these units at the peak of the pandemic in Detroit, MI. PATIENTS: The coronavirus disease 2019 cohort included patients diagnosed with coronavirus disease 2019 who were intubated for respiratory failure from March 12, 2020, to April 13, 2020. The historic control (noncoronavirus disease 2019) group consisted of patients who were admitted to the medical ICU in the year spanning from November 1, 2018 to October 31, 2019, with a need for mechanical ventilation that was not related to surgery or a neurologic reason. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: To identify how many patients in each cohort had unplanned extubations, an electronic medical records query for patients with two intubations within 30 days was performed, in addition to a review of our institutional quality and safety database of reported self-extubations. Medical charts were manually reviewed by board-certified anesthesiologists to confirm each event was an unplanned extubation followed by a reintubation within 24 hours. There was a significantly greater incidence of unplanned extubations resulting in reintubation events in the coronavirus disease 2019 cohort than in the noncoronavirus disease 2019 cohort (coronavirus disease 2019 cohort: 167 total admissions with 22 events-13.2%; noncoronavirus disease 2019 cohort: 326 total admissions with 14 events-4.3%; p < 0.001). When the rate of unplanned extubations was expressed per 100 intubated days, there was not a significant difference between the groups (0.88 and 0.57, respectively; p = 0.269). CONCLUSIONS: Coronavirus disease 2019 patients have a higher incidence of unplanned extubation that requires reintubation than noncoronavirus disease 2019 patients. Further study is necessary to evaluate the variables that contribute to this higher incidence and clinical strategies that can reduce it.
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Duchenne muscular dystrophy (DMD) is a progressive, lethal, X-linked disease of skeletal and cardiac muscles caused by mutations in the dystrophin gene. Loss of dystrophin leads to muscle fiber damage and impairment of satellite cell asymmetric division, which are essential for muscle regeneration. These processes ultimately result in muscle wasting and the replacement of the degenerating muscles by fibrogenic cells, a process that leads to the generation of fibrotic tissues. Preimplantation factor (PIF) is an evolutionary conserved 15-amino acid peptide secreted by viable mammalian embryos. Synthetic PIF (sPIF) reproduces the protective/regenerative effects of the endogenous peptide in immune disorders and transplantation models. In this study, we demonstrated that sPIF treatment promoted mouse and human myoblast differentiation and inhibited the expression of collagen 1A1, collagen 1A2, and TGF-ß in DMD patient-derived myoblasts. Additionally, sPIF increased the expression of utrophin, a homolog of dystrophin protein. sPIF effects were mediated via the upregulation of lncRNA H19 and miR-675 and downregulation of let-7. sPIF also inhibited the expression of miR-21, a major fibrosis regulator. The administration of sPIF in mdx mice significantly decreased serum creatine kinase and collagen I and collagen IV expression in the diaphragm, whereas it increased utrophin expression in the diaphragm, heart and quadriceps muscles. In conclusion, sPIF promoted the differentiation of DMD myoblasts, increased utrophin expression via the H19/miRNA-675/let-7 pathway, and reduced muscle fibrosis possibly via the upregulation of miR-675 and inhibition of miR-21 expression. These findings strongly support pursuing sPIF as a potential therapeutic agent for DMD. Moreover, the completion of an sPIF phase I safety trial will further promote the use of sPIF for the treatment of muscular dystrophies.
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Proteínas Portadoras/genética , MicroARNs/genética , Distrofia Muscular de Duchenne/genética , Mioblastos/metabolismo , Utrofina/metabolismo , Animales , Diferenciación Celular , Humanos , RatonesRESUMEN
Secreted protein acidic and rich in cysteine (SPARC) regulates cell-extracellular matrix interactions that influence cell adhesion and migration. We have demonstrated that SPARC is highly expressed in human gliomas, and it promotes brain tumor invasion in vitro and in vivo. To further our understanding regarding SPARC function in glioma migration, we transfected SPARC-green fluorescent protein (GFP) and control GFP vectors into U87MG cells, and assessed the effects of SPARC on cell morphology, migration, and invasion after 24 h. The expression of SPARC was associated with elongated cell morphology, and increased migration and invasion. The effects of SPARC on downstream signaling were assessed from 0 to 6 h and 24 h. SPARC increased the levels of total and phosphorylated HSP27; the latter was preceded by activation of p38 MAPK and inhibited by the p38 MAPK inhibitor SB203580. Augmented expression of SPARC was correlated with increased levels of HSP27 mRNA. In a panel of glioma cell lines, increasing levels of SPARC correlated with increasing total and phosphorylated HSP27. SPARC and HSP27 were colocalized to invading cells in vivo. Inhibition of HSP27 mRNA reversed the SPARC-induced changes in cell morphology, migration, and invasion in vitro. These data indicate that HSP27, a protein that regulates actin polymerization, cell contraction, and migration, is a novel downstream effector of SPARC-regulated cell morphology and migration. As such, it is a potential therapeutic target to inhibit SPARC-induced glioma invasion.
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Movimiento Celular/fisiología , Glioma/patología , Proteínas de Choque Térmico/fisiología , Proteínas de Neoplasias/fisiología , Osteonectina/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Glioma/genética , Glioma/metabolismo , Proteínas de Choque Térmico HSP27 , Humanos , Chaperonas Moleculares , Invasividad Neoplásica/patología , Osteonectina/genética , Osteonectina/fisiología , Células Tumorales CultivadasRESUMEN
Glioblastomas are heterogeneous tumors displaying regions of necrosis, proliferation, angiogenesis, apoptosis and invasion. SPARC, a matricellular protein that negatively regulates angiogenesis and cell proliferation, but enhances cell deadhesion from matrix, is upregulated in gliomas (Grades II-IV). We previously demonstrated that SPARC promotes invasion while concomitantly decreasing tumor growth, in part by decreasing proliferation of the tumor cells. In other cancer types, SPARC has been shown to influence tumor growth by altering matrix production, and by decreasing angiogenesis via interfering with the VEGF-VEGFR1 signaling pathway. We therefore examined whether the SPARC-induced decrease in glioma tumor growth was also, in part, due to alterations in matrix and/or decreased vascularity, and assessed SPARC-VEGF interactions. The data demonstrate that SPARC upregulates glioma matrix, collagen I is a constituent of the matrix and SPARC promotes collagen fibrillogenesis. Furthermore, SPARC suppressed glioma vascularity, and this was accompanied by decreased VEGF expression and secretion, which was, in part, due to reduced VEGF165 transcript abundance. These data indicate that SPARC modulates glioma growth by altering the tumor microenvironment and by suppressing tumor vascularity through suppression of VEGF expression and secretion. These experiments implicate a novel mechanism, whereby SPARC regulates VEGF function by limiting the available growth factor. Because SPARC is considered to be a therapeutic target for gliomas, a further understanding of its complex signaling mechanisms is important, as targeting SPARC to decrease invasion could undesirably lead to the growth of more vascular and proliferative tumors.
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Neoplasias Encefálicas/patología , Glioma/patología , Osteonectina/fisiología , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Secuencia de Bases , Neoplasias Encefálicas/irrigación sanguínea , Línea Celular Tumoral , Colágeno Tipo I/biosíntesis , Cartilla de ADN , Glioma/irrigación sanguínea , Inmunohistoquímica , Inmunoprecipitación , Ratas , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
We characterized the expression and function of the endoplasmic reticulum protein GRP78 in glial tumors. GRP78 is highly expressed in glioblastomas but not in oligodendrogliomas, and its expression is inversely correlated with median patient survival. Overexpression of GRP78 in glioma cells decreases caspase 7 activation and renders the cells resistant to etoposide- and cisplatin-induced apoptosis, whereas silencing of GRP78 decreases cell growth and sensitizes glioma cells to etoposide, cisplatin, and gamma-radiation. Thus, GRP78 contributes to the increased apoptosis resistance and growth of glioma cells and may provide a target for enhancing the therapeutic responsiveness of these tumors.
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Apoptosis/fisiología , Neoplasias Encefálicas/metabolismo , Proliferación Celular , Glioma/metabolismo , Proteínas de Choque Térmico/biosíntesis , Chaperonas Moleculares/biosíntesis , Biomarcadores de Tumor/análisis , Western Blotting , Neoplasias Encefálicas/mortalidad , Caspasa 7 , Línea Celular Tumoral , Resistencia a Antineoplásicos/fisiología , Chaperón BiP del Retículo Endoplásmico , Activación Enzimática/fisiología , Expresión Génica , Perfilación de la Expresión Génica , Glioma/mortalidad , Humanos , Inmunohistoquímica , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transfección , Regulación hacia ArribaRESUMEN
In this study, we examined the expression and functions of related to testes-specific, vespid, and pathogenesis protein 1 (RTVP-1) in glioma cells. RTVP-1 was expressed in high levels in glioblastomas, whereas its expression in low-grade astrocytomas and normal brains was very low. Transfection of glioma cells with small interfering RNAs targeting RTVP-1 decreased cell proliferation in all the cell lines examined and induced cell apoptosis in some of them. Overexpression of RTVP-1 increased astrocyte and glioma cell proliferation and the anchorage-independent growth of the cells. In addition, overexpression of RTVP-1 rendered glioma cells more resistant to the apoptotic effect of tumor necrosis factor-related apoptosis-inducing ligand and serum deprivation. To delineate the molecular mechanisms involved in the survival effects of RTVP-1, we examined the expression and phosphorylation of various apoptosis-related proteins. We found that overexpression of RTVP-1 decreased the phosphorylation of c-Jun-NH2-kinase and increased the expression of Bcl2 and that the protective effect of RTVP-1 was partially mediated by Bcl2. Finally, we found that RTVP-1 regulated the invasion of glioma cells as was evident by their enhanced migration through Matrigel and by their increased invasion in a spheroid confrontation assay. The increased invasive potential of the RTVP-1 overexpressors was also shown by the increased activity of matrix metalloproteinase 2 in these cells. Our results suggest that the expression of RTVP-1 is correlated with the degree of malignancy of astrocytic tumors and that RTVP-1 is involved in the regulation of the growth, survival, and invasion of glioma cells. Collectively, these findings suggest that RTVP-1 is a potential therapeutic target in gliomas.
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Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Glioma/metabolismo , Glioma/patología , Proteínas de Neoplasias/biosíntesis , Proteínas del Tejido Nervioso/biosíntesis , Secuencia de Aminoácidos , Apoptosis/fisiología , Astrocitoma/enzimología , Astrocitoma/metabolismo , Astrocitoma/patología , Neoplasias Encefálicas/enzimología , Procesos de Crecimiento Celular/fisiología , Línea Celular Tumoral , Supervivencia Celular/fisiología , Glioblastoma/enzimología , Glioblastoma/metabolismo , Glioblastoma/patología , Glioma/enzimología , Humanos , Metaloproteinasa 2 de la Matriz/metabolismo , Proteínas de la Membrana , Datos de Secuencia Molecular , Invasividad NeoplásicaRESUMEN
Duchenne muscular dystrophy (DMD) is a degenerative lethal, X-linked disease of skeletal and cardiac muscles caused by mutations in the dystrophin gene. Cell therapy using different cell types, including mesenchymal stromal cells (MSCs), has been considered as a potential approach for the treatment of DMD. MSCs can be obtained from autologous sources such as bone marrow and adipose tissues or from allogeneic placenta and umbilical cord. The safety and therapeutic impact of these cells has been demonstrated in pre-clinical and clinical studies and their functions are attributed to paracrine effects that are mediated by secreted cytokines and extracellular vesicles. Here, we studied the therapeutic effects of placenta-derived MSCs (PL-MSCs) and their secreted exosomes using mouse and human myoblasts from healthy controls, Duchenne patients and mdx mice. Treatment of myoblasts with conditioned medium or exosomes secreted by PL-MSCs increased the differentiation of these cells and decreased the expression of fibrogenic genes in DMD patient myoblasts. In addition, these treatments also increased the expression of utrophin in these cells. Using a quantitative miR-29c reporter, we demonstrated that the PL-MSC effects were partly mediated by the transfer of exosomal miR-29c. Intramuscular transplantation of PL-MSCs in mdx mice resulted in decreased creatine kinase levels. PL-MSCs significantly decreased the expression of TGF-ß and the level of fibrosis in the diaphragm and cardiac muscles, inhibited inflammation and increased utrophin expression. In vivo imaging analyses using MSCs labeled with gold nanoparticles or fluorescent dyes demonstrated localization of the cells in the muscle tissues up to 3 weeks post treatment. Altogether, these results demonstrate that PL-MSCs and their secreted exosomes have important clinical applications in cell therapy of DMD partly via the targeted delivery of exosomal miR-29c.
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Exosomas/metabolismo , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/metabolismo , Distrofia Muscular de Duchenne/tratamiento farmacológico , Placenta/citología , Tejido Adiposo/metabolismo , Animales , Diferenciación Celular/efectos de los fármacos , Medios de Cultivo Condicionados/metabolismo , Distrofina/metabolismo , Vesículas Extracelulares/metabolismo , Femenino , Colorantes Fluorescentes/química , Regulación de la Expresión Génica/efectos de los fármacos , Oro/química , Humanos , Nanopartículas del Metal/química , Ratones Endogámicos mdx , MicroARNs/metabolismo , Mioblastos/efectos de los fármacos , Placenta/efectos de los fármacos , Embarazo , Transfección/métodos , Factor de Crecimiento Transformador beta/metabolismo , Cordón Umbilical/metabolismo , Utrofina/metabolismoRESUMEN
Despite advances in novel therapeutic approaches for the treatment of glioblastoma (GBM), the median survival of 12-14 months has not changed significantly. Therefore, there is an imperative need to identify molecular mechanisms that play a role in patient survival. Here, we analyzed the expression and functions of a novel lncRNA, TALNEC2 that was identified using RNA seq of E2F1-regulated lncRNAs. TALNEC2 was localized to the cytosol and its expression was E2F1-regulated and cell-cycle dependent. TALNEC2 was highly expressed in GBM with poor prognosis, in GBM specimens derived from short-term survivors and in glioma cells and glioma stem cells (GSCs). Silencing of TALNEC2 inhibited cell proliferation and arrested the cells in the G1\S phase of the cell cycle in various cancer cell lines. In addition, silencing of TALNEC2 decreased the self-renewal and mesenchymal transformation of GSCs, increased sensitivity of these cells to radiation and prolonged survival of mice bearing GSC-derived xenografts. Using miRNA array analysis, we identified specific miRNAs that were altered in the silenced cells that were associated with cell-cycle progression, proliferation and mesenchymal transformation. Two of the downregulated miRNAs, miR-21 and miR-191, mediated some of TALNEC2 effects on the stemness and mesenchymal transformation of GSCs. In conclusion, we identified a novel E2F1-regulated lncRNA that is highly expressed in GBM and in tumors from patients of short-term survival. The expression of TALNEC2 is associated with the increased tumorigenic potential of GSCs and their resistance to radiation. We conclude that TALNEC2 is an attractive therapeutic target for the treatment of GBM.
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Autorrenovación de las Células/genética , Glioma/genética , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/efectos de la radiación , ARN Largo no Codificante/genética , Tolerancia a Radiación/genética , Animales , Proliferación Celular , Modelos Animales de Enfermedad , Transición Epitelial-Mesenquimal/genética , Puntos de Control de la Fase G1 del Ciclo Celular/genética , Expresión Génica , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Silenciador del Gen , Glioma/mortalidad , Glioma/patología , Glioma/radioterapia , Humanos , Ratones , MicroARNs/genética , Pronóstico , Transporte de ARN , Resultado del Tratamiento , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Recent studies have proposed that abnormal glutamatergic neurotransmission and glial pathology play an important role in the etiology and manifestation of depression. It was postulated that restoration of normal glutamatergic transmission, by enhancing glutamate uptake, may have a beneficial effect on depression. We examined this hypothesis using unique human glial-like mesenchymal stem cells (MSCs), which in addition to inherent properties of migration to regions of injury and secretion of neurotrophic factors, were differentiated to express high levels of functional glutamate transporters (excitatory amino acid transporters; EAAT). Additionally, gold nanoparticles (GNPs), which serve as contrast agents for CT imaging, were loaded into the cells for non-invasive, real-time imaging and tracking of MSC migration and final location within the brain. MSC-EAAT (2×105; 10 µl) were administered (i.c.v.) to Flinder Sensitive Line rats (FSLs), a genetic model for depression, and longitudinal behavioral and molecular changes were monitored. FSL rats treated with MSC-EAAT showed attenuated depressive-like behaviors (measured by the forced swim test, novelty exploration test and sucrose self-administration paradigm), as compared to controls. CT imaging, Flame Atomic Absorption Spectroscopy analysis and immunohistochemistry showed that the majority of MSCs homed specifically to the dentate gyrus of the hippocampus, a region showing structural brain changes in depression, including loss of glial cells. mRNA and protein levels of EAAT1 and BDNF were significantly elevated in the hippocampus of MSC-EAAT-treated FSLs. Our findings indicate that MSC-EAATs effectively improve depressive-like manifestations, possibly in part by increasing both glutamate uptake and neurotropic factor secretion in the hippocampus.
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Sistema de Transporte de Aminoácidos X-AG/biosíntesis , Depresión/terapia , Expresión Génica , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/fisiología , Animales , Conducta Animal , Giro Dentado/patología , Depresión/patología , Modelos Animales de Enfermedad , Humanos , Estudios Longitudinales , Ratas , Usos TerapéuticosRESUMEN
Glioblastoma (GBM) is the most aggressive primary brain tumor with poor prognosis. Here, we studied the effects of phenformin, a mitochondrial complex I inhibitor and more potent chemical analog of the diabetes drug metformin on the inhibition of cell growth and induction of apoptosis of glioma stem cells (GSCs) using both in vitro and in vivo models. Phenformin inhibited the self-renewal of GSCs, decreased the expression of stemness and mesenchymal markers and increased the expression of miR-124, 137 and let-7. Silencing of let-7 abrogated phenformin effects on the self-renewal of GSCs via a pathway associated with inhibition of H19 and HMGA2 expression. Moreover, we demonstrate that phenformin inhibited tumor growth and prolonged the overall survival of mice orthotopically transplanted with GSCs. Combined treatments of phenformin and temozolomide exerted an increased antitumor effect on GSCs in vitro and in vivo. In addition, dichloroacetate, an inhibitor of the glycolysis enzyme pyruvate dehydrogenase kinase, that decreases lactic acidosis induced by biguanides, enhanced phenformin effects on the induction of cell death in GSCs and prolonged the survival of xenograft-bearing mice. Our results demonstrate for the first time that phenformin targets GSCs and can be efficiently combined with current therapies for GBM treatment and GSC eradication.
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Neoplasias Encefálicas/tratamiento farmacológico , Glioblastoma/tratamiento farmacológico , Glioma/tratamiento farmacológico , Células Madre Neoplásicas/efectos de los fármacos , Fenformina/farmacología , Animales , Apoptosis/efectos de los fármacos , Neoplasias Encefálicas/patología , Proliferación Celular , Ácido Dicloroacético/farmacología , Reposicionamiento de Medicamentos , Silenciador del Gen , Glioblastoma/patología , Glioma/patología , Proteína HMGA2/antagonistas & inhibidores , Humanos , Hipoglucemiantes/química , Lentivirus , Ratones , Ratones Desnudos , MicroARNs/metabolismo , Recurrencia Local de Neoplasia , Trasplante de Neoplasias , Células Madre Neoplásicas/patología , ARN Largo no Codificante/antagonistas & inhibidoresRESUMEN
Gliomas are the most common primary brain tumor and one of the most lethal solid tumors. Mechanistic studies into identification of novel biomarkers are needed to develop new therapeutic strategies for this deadly disease. The objective for this study was to explore the potential direct impact of IL-17-IL-17R interaction in gliomas. Immunohistochemistry and flow cytometry analysis of 12 tumor samples obtained from patients with high grade gliomas revealed that a considerable population (2-19%) of cells in all malignant gliomas expressed IL-17RA, with remarkable co-expression of the glioma stem cell (GSC) markers CD133, Nestin, and Sox2. IL-17 enhanced the self-renewal of GSCs as determined by proliferation and Matrigel® colony assays. IL-17 also induced cytokine/chemokine (IL-6, IL-8, interferon-γ-inducible protein [IP-10], and monocyte chemoattractant protein-1 [MCP-1]) secretion in GSCs, which were differentially blocked by antibodies against IL-17R and IL-6R. Western blot analysis showed that IL-17 modulated the activity of signal transducer and activator of transcription 3 (STAT3), nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB), glycogen synthase kinase-3ß (GSK-3ß) and ß-catenin in GSCs. While IL-17R-mediated secretion of IL-6 and IL-8 were significantly blocked by inhibitors of NF-κB and STAT3; NF-κB inhibitor was more potent than STAT3 inhibitor in blocking IL-17-induced MCP-1 secretion. Overall, our results suggest that IL-17-IL-17R interaction in GSCs induces an autocrine/paracrine cytokine feedback loop, which may provide an important signaling component for maintenance/self-renewal of GSCs via constitutive activation of both NF-κB and STAT3. The results also strongly implicate IL-17R as an important functional biomarker for therapeutic targeting of GSCs.
Asunto(s)
Glioma/metabolismo , Interleucina-17/biosíntesis , Anciano , Proliferación Celular/fisiología , Femenino , Glioma/genética , Glioma/patología , Humanos , Masculino , Persona de Mediana Edad , FN-kappa B/metabolismo , Transducción de SeñalRESUMEN
Glioblastoma (GBM), the most aggressive primary brain tumors, are highly infiltrative. Although GBM express high Ras activity and Ras proteins have been implicated in gliomagenesis, Ras-activating mutations are not frequent in these tumors. RasGRP3, an important signaling protein responsive to diacylglycerol (DAG), increases Ras activation. Here, we examined the expression and functions of RasGRP3 in GBM and glioma cells. RasGRP3 expression was upregulated in GBM specimens and glioma stem cells compared with normal brains and neural stem cells, respectively. RasGRP3 activated Ras and Rap1 in glioma cells and increased cell migration and invasion partially via Ras activation. Using pull-down assay and mass spectroscopy we identified the actin-related protein, Arp3, as a novel interacting protein of RasGRP3. The interaction of RasGRP3 and Arp3 was validated by immunofluorescence staining and co-immunoprecipitation, and PMA, which activates RasGRP3 and induces its translocation to the peri-nuclear region, increased the association of Arp3 and RasGRP3. Arp3 was upregulated in GBM, regulated cell spreading and migration and its silencing partially decreased these effects of RasGRP3 in glioma cells. In summary, RasGRP3 acts as an important integrating signaling protein of the DAG and Ras signaling pathways and actin polymerization and represents an important therapeutic target in GBM.
Asunto(s)
Proteína 3 Relacionada con la Actina/metabolismo , Neoplasias Encefálicas/patología , Movimiento Celular/fisiología , Glioma/patología , Factores de Intercambio de Guanina Nucleótido/metabolismo , Proteína 3 Relacionada con la Actina/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Glioma/genética , Glioma/metabolismo , Factores de Intercambio de Guanina Nucleótido/genética , Humanos , Transducción de Señal , Transfección , Factores de Intercambio de Guanina Nucleótido rasRESUMEN
Glioblastoma (GBM) are characterized by increased invasion into the surrounding normal brain tissue. RTVP-1 is highly expressed in GBM and regulates the migration and invasion of glioma cells. To further study RTVP-1 effects we performed a pull-down assay using His-tagged RTVP-1 followed by mass spectrometry and found that RTVP-1 was associated with the actin polymerization regulator, N-WASP. This association was further validated by co-immunoprecipitation and FRET analysis. We found that RTVP-1 increased cell spreading, migration and invasion and these effects were at least partly mediated by N-WASP. Another protein which was found by the pull-down assay to interact with RTVP-1 is hnRNPK. This protein has been recently reported to associate with and to inhibit the effect of N-WASP on cell spreading. hnRNPK decreased cell migration, spreading and invasion in glioma cells. Using co-immunoprecipitation we validated the interactions of hnRNPK with N-WASP and RTVP-1 in glioma cells. In addition, we found that overexpression of RTVP-1 decreased the association of N-WASP and hnRNPK. In summary, we report that RTVP-1 regulates glioma cell spreading, migration and invasion and that these effects are mediated via interaction with N-WASP and by interfering with the inhibitory effect of hnRNPK on the function of this protein.
Asunto(s)
Neoplasias Encefálicas/metabolismo , Movimiento Celular , Glioblastoma/metabolismo , Proteínas de Neoplasias/metabolismo , Células Madre Neoplásicas/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Ribonucleoproteínas/metabolismo , Proteína Neuronal del Síndrome de Wiskott-Aldrich/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Forma de la Célula , Transferencia Resonante de Energía de Fluorescencia , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Glioblastoma/patología , Ribonucleoproteína Heterogénea-Nuclear Grupo K , Humanos , Inmunoprecipitación , Espectrometría de Masas , Proteínas de la Membrana , Invasividad Neoplásica , Proteínas de Neoplasias/genética , Células Madre Neoplásicas/patología , Proteínas del Tejido Nervioso/genética , Unión Proteica , Proteómica/métodos , Interferencia de ARN , Ribonucleoproteínas/genética , Transducción de Señal , Transfección , Células Tumorales Cultivadas , Proteína Neuronal del Síndrome de Wiskott-Aldrich/genéticaRESUMEN
Glioblastomas (GBMs), the most aggressive primary brain tumors, exhibit increased invasiveness and resistance to anti-tumor treatments. We explored the role of RTVP-1, a glioma-associated protein that promotes glioma cell migration, in the mesenchymal transformation of GBM. Analysis of The Cancer Genome Atlas (TCGA) demonstrated that RTVP-1 expression was higher in mesenchymal GBM and predicted tumor recurrence and poor clinical outcome. ChiP analysis revealed that the RTVP-1 promoter binds STAT3 and C/EBPß, two master transcription factors that regulate mesenchymal transformation of GBM. In addition, IL-6 induced RTVP-1 expression in a STAT3-dependent manner. RTVP-1 increased the migration and mesenchymal transformation of glioma cells. Similarly, overexpression of RTVP-1 in human neural stem cells induced mesenchymal differentiation, whereas silencing of RTVP-1 in glioma stem cells (GSCs) decreased the mesenchymal transformation and stemness of these cells. Silencing of RTVP-1 also increased the survival of mice bearing GSC-derived xenografts. Using gene array analysis of RTVP-1 silenced glioma cells we identified IL-6 as a mediator of RTVP-1 effects on the mesenchymal transformation and migration of GSCs, therefore acting in a positive feedback loop by upregulating RTVP-1 expression via the STAT3 pathway. Collectively, these results implicate RTVP-1 as a novel prognostic marker and therapeutic target in GBM.