RESUMEN
Glioblastoma multiforme (GBM) is a highly aggressive malignancy and represents the most common brain tumor in adults. To better understand its biology for new and effective therapies, we examined the role of GDP-mannose pyrophosphorylase B (GMPPB), a key unit of the GDP-mannose pyrophosphorylase (GDP-MP) that catalyzes the formation of GDP-mannose. Impaired GMPPB function will reduce the amount of GDP-mannose available for O-mannosylation. Abnormal O-mannosylation of alpha dystroglycan (α-DG) has been reported to be involved in cancer metastasis and arenavirus entry. Here, we found that GMPPB is highly expressed in a panel of GBM cell lines and clinical samples and that expression of GMPPB is positively correlated with the WHO grade of gliomas. Additionally, expression of GMPPB was negatively correlated with the prognosis of GBM patients. We demonstrate that silencing GMPPB inhibits the proliferation, migration, and invasion of GBM cells both in vitro and in vivo and that overexpression of GMPPB exhibits the opposite effects. Consequently, targeting GMPPB in GBM cells results in impaired GBM tumor growth and invasion. Finally, we identify that the Hippo/MMP3 axis is essential for GMPPB-promoted GBM aggressiveness. These findings indicate that GMPPB represents a potential novel target for GBM treatment.
Asunto(s)
Neoplasias Encefálicas , Silenciador del Gen , Glioblastoma , Adulto , Humanos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Glioblastoma/genética , Glioblastoma/metabolismo , Manosa , Metaloproteinasa 3 de la Matriz/metabolismoRESUMEN
PURPOSE: This study investigated the protective effect of probucol on Müller cells exposed to high glucose conditions and examined potential mechanisms of action. METHODS: Primary human retinal Müller cells were incubated with high glucose (HG, 35 mM) in the present or absence of different concentrations of probucol for 24 h. Cell viability was determined using the CCK-8 method. Mitochondrial membrane potential (MMP) was measured using JC-1 staining and cell cycle by flow cytometry. The expression of nuclear factor E2-related factor 2 (Nrf2), glutamate-cysteine ligase catalytic subunit, and p62 was quantified using quantitative polymerase chain reaction and western blot. RESULTS: We found that HG inhibited cell proliferation, arrested cell cycle, and increased MMP in human Müller cells. Probucol activated the Nrf2/p62 pathway and upregulated the anti-apoptotic protein, Bcl2, and attenuated HG-mediated damage in Müller cells. CONCLUSIONS: Our results suggest that probucol may protect Müller cells from HG-induced damage through enhancing the Nrf2/p62 signaling pathway.
Asunto(s)
Células Ependimogliales , Probucol , Transducción de Señal , Humanos , Células Ependimogliales/efectos de los fármacos , Células Ependimogliales/metabolismo , Glucosa/metabolismo , Glucosa/farmacología , Factor 2 Relacionado con NF-E2 , Probucol/farmacologíaRESUMEN
Although there have been recent advances in the molecular pathology of ependymomas, little is known about the underlying molecular evolution during its development. Here, we assessed the clinical, pathological and molecular evolutionary process of ependymoma recurrence in a 9-year-old patient who had seven recurrences of supratentorial ependymoma and died from intracranial multiregional recurrences at the age of 19 years old. Whole-genome sequencing (WGS) of 7 tumor samples (1 primary and 6 subsequent recurrent tumors) was performed to elucidate the mutation landscape and identify potential driver mutations for tumor evolution. The genetic profiles of the seven tumor specimens showed significant heterogeneity and suggested a highly branched evolutionary pattern. The mutational signatures and chromothripsis changed with treatments. Strikingly, adhesion G protein-coupled receptor L3 (ADGRL3, also known as Latrophilins 3, LPNH3) was found to be consistently mutated during the entire disease process. However, Sanger sequencing of other 78 ependymoma patients who underwent surgery at our institution showed no genetic alteration of ADGRL3, as found in the present case. The mRNA levels of ADGRL3 were significantly lower in ependymomas (n = 36), as compared with normal brain tissue (n = 3). Grade III ependymomas had the lowest ADGRL3 expression. Moreover, ependymomas with lower mRNA level of ADGRL3 had shorter overall survival. Our findings, therefore, demonstrate a rare evolutionary process of ependymoma involving ADGRL3.
Asunto(s)
Ependimoma , Adulto , Niño , Ependimoma/genética , Ependimoma/patología , Ependimoma/cirugía , Humanos , Mutación , ARN Mensajero , Receptores Acoplados a Proteínas G/genética , Adulto JovenRESUMEN
BACKGROUND: Epidermal growth factor receptor (EGFR) and lanthionine synthetase C-like 2 (LanCL2) genes locate in the same amplicon, and co-amplification of EGFR and LANCL2 is frequent in glioblastoma. However, the prognostic value of LANCL2 and EGFR co-amplification, and their mRNA and protein expression in glioblastoma remain unclear yet. METHODS: This study analyzed the prognostic values of the copy number variations (CNVs), mRNA and protein expression of LANCL2 and EGFR in 575 glioblastoma patients in TCGA database and 100 glioblastoma patients in tumor banks of the Shenzhen Second People's Hospital and the Sun Yat-sen University Cancer Center. RESULTS: The amplification of LANCL2 or EGFR, and their co-amplification were frequent in glioblastoma of TCGA database and our tumor banks. A significant correlation was found between the CNVs of LANCL2 and EGFR (p < 0.001). CNVs of LANCL2 or EGFR were significantly correlated with IDH1/2 mutation but not MGMT promoter methylation. Multivariate analysis showed that LANCL2 amplification was significantly correlated with reduced overall survival (OS) in younger (< 60 years) glioblastoma patients of TCGA database (p = 0.043, HR = 1.657) and our tumor banks (p = 0.018, HR = 2.199). However, LANCL2 or EGFR amplification, and their co-amplification had no significant impact on OS in older (≥ 60 years) or IDH1/2-wild-type glioblastoma patients. mRNA and protein overexpression of LANCL2 and EGFR was also frequently found in glioblastoma. The mRNA expression rather than the protein expression of LANCL2 and EGFR was positively correlated (p < 0.001). However, mRNA or protein expression of EGFR and LANCL2 was not significantly correlated with OS of glioblastoma patients. The protein expression level of LANCL2, rather than EGFR, was elevated in relapsing glioblastoma, compared with newly diagnosed glioblastoma. In addition, the intracellular localization of LanCL2, not EGFR, was associated with the grade of gliomas. CONCLUSIONS: Taken together, amplification and mRNA overexpression of LANCL2 and EGFR, and their co-amplification and co-expression were frequent in glioblastoma patients. Our findings suggest that amplification of LANCL2 and EGFR were the independent diagnostic biomarkers for glioblastoma patients, and LANCL2 amplification was a significant prognostic factor for OS in younger glioblastoma patients.
Asunto(s)
Neoplasias Encefálicas , Receptores ErbB/genética , Glioblastoma , Proteínas de la Membrana/genética , Proteínas de Unión a Fosfato/genética , Anciano , Biomarcadores de Tumor/genética , Neoplasias Encefálicas/genética , Variaciones en el Número de Copia de ADN/genética , Receptores ErbB/metabolismo , Glioblastoma/genética , Humanos , Mutación , Recurrencia Local de Neoplasia , Pronóstico , ARN Mensajero/genéticaRESUMEN
BACKGROUND: Glioblastoma multiforme, the most aggressive and malignant primary brain tumor, is characterized by rapid growth and extensive infiltration to neighboring normal brain parenchyma. Our previous studies delineated a crosstalk between PI3K/Akt and JNK signaling pathways, and a moderate anti-glioblastoma synergism caused by the combined inhibition of PI3K p110ß (PI3Kß) isoform and JNK. However, this combination strategy is not potent enough. MLK3, an upstream regulator of ERK and JNK, may replace JNK to exert stronger synergism with PI3Kß. METHODS: To develop a new combination strategy with stronger synergism, the expression pattern and roles of MLK3 in glioblastoma patient's specimens and cell lines were firstly investigated. Then glioblastoma cells and xenografts in nude mice were treated with the PI3Kß inhibitor AZD6482 and the MLK3 inhibitor URMC-099 alone or in combination to evaluate their combination effects on tumor cell growth and motility. The combination effects on cytoskeletal structures such as lamellipodia and focal adhesions were also evaluated. RESULTS: MLK3 protein was overexpressed in both newly diagnosed and relapsing glioblastoma patients' specimens. Silencing of MLK3 using siRNA duplexes significantly suppressed migration and invasion, but promoted attachment of glioblastoma cells. Combined inhibition of PI3Kß and MLK3 exhibited synergistic inhibitory effects on glioblastoma cell proliferation, migration and invasion, as well as the formation of lamellipodia and focal adhesions. Furthermore, combination of AZD6482 and URMC-099 effectively decreased glioblastoma xenograft growth in nude mice. Glioblastoma cells treated with this drug combination showed reduced phosphorylation of Akt and ERK, and decreased protein expression of ROCK2 and Zyxin. CONCLUSION: Taken together, combination of AZD6482 and URMC-099 showed strong synergistic anti-tumor effects on glioblastoma in vitro and in vivo. Our findings suggest that combined inhibition of PI3Kß and MLK3 may serve as an attractive therapeutic approach for glioblastoma multiforme.
RESUMEN
The ECM protein EFEMP1 (fibulin-3) is associated with all types of solid tumor through its cell context-dependent dual function. A variant of fibulin-3 was engineered by truncation and mutation to alleviate its oncogenic function, specifically the proinvasive role in glioblastoma multiforme (GBM) cells at stem-like state. ZR30 is an in vitro synthesized 39-kDa protein of human fibulin-3 variant. It has a therapeutic effect in intracranial xenograft models of human GBM, through suppression of epidermal growth factor receptor/AKT and NOTCH1/AKT signaling in GBM cells and extracellular MMP2 activation. Glioblastoma multiforme is highly vascular, with leaky blood vessels formed by tumor cells expressing endothelial cell markers, including CD31. Here we studied GBM intracranial xenografts, 2 weeks after intratumoral injection of ZR30 or PBS, by CD31 immunohistochemistry. We found a 70% reduction of blood vessel density in ZR30-treated xenografts compared with that of PBS-treated ones. Matrigel plug assays showed the effect of ZR30 on suppressing angiogenesis. We further studied the effect of ZR30 on genes involved in endothelial transdifferentiation (ETD), in 7 primary cultures derived from 3 GBMs under different culture conditions. Two GBM cultures formed mesh structures with upregulation of ETD genes shortly after culture in Matrigel Matrix, and ZR30 suppressed both. ZR30 also downregulated ETD genes in two GBM cultures with high expression of these genes. In conclusion, multifaceted tumor suppression effects of human fibulin-3 variant include both suppression of angiogenesis and vasculogenic mimicry in GBM.
Asunto(s)
Neoplasias Encefálicas/genética , Proteínas de la Matriz Extracelular/genética , Glioblastoma/genética , Animales , Línea Celular Tumoral , Proliferación Celular/genética , Regulación hacia Abajo/genética , Descubrimiento de Drogas/métodos , Células Endoteliales/metabolismo , Receptores ErbB/genética , Femenino , Expresión Génica/genética , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neovascularización Patológica/genética , Transducción de Señal/genética , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
BACKGROUND: Gliomas represent the largest class of primary central nervous system neoplasms, many subtypes of which exhibit poor prognoses. Surgery followed by radiotherapy and chemotherapy has been used as a standard strategy but yielded unsatisfactory improvements in patient survival outcomes. The S-phase kinase protein 2 (Skp2), a critical component of the E3-ligase SCF complex, has been documented in tumorigenesis in various cancer types but its role in glioma has yet to be fully clarified. In this study, we investigated the function of Skp2 in the proliferation, stem cell maintenance, and drug sensitivity to temozolomide (TMZ) of glioma. METHODS: To investigate the role of Skp2 in the prognosis of patients with glioma, we first analyzed data in databases TCGA and GTEx. To further clarify the effect of Skp2 on glioma cell proliferation, we suppressed its level in glioblastoma (GBM) cell lines through knockdown and small molecule inhibitors (lovastatin and SZL-P1-41). We then detected cell growth, colony formation, sphere formation, drug sensitivity, and in vivo tumor formation in xenograft mice model. RESULTS: Skp2 mRNA level was higher in both low-grade glioma and GBM than normal brain tissues. The knockdown of Skp2 increased cell sensitivity to TMZ, decreased cell proliferation and tumorigenesis. In addition, Skp2 level was found increased upon stem cells enriching, while the knockdown of Skp2 led to reduced sphere numbers. Downregulation of Skp2 also induced senescence. Repurposing of lovastatin and novel compound SZL-P1-41 suppressed Skp2 effectively, and enhanced glioma cell sensitivity to TMZ in vitro and in vivo. CONCLUSION: Our data demonstrated that Skp2 modulated glioma cell proliferation in vitro and in vivo, stem cell maintenance, and cell sensitivity to TMZ, which indicated that Skp2 could be a potential target for long-term treatment.
RESUMEN
OBJECTIVE: Optical molecular imaging technology that indiscriminately detects intracranial glioblastoma (GBM) can help neurosurgeons effectively remove tumor masses. Transferrin receptor 1 (TfR 1) is a diagnostic and therapeutic target in GBM. A TfR 1-targeted peptide, CRTIGPSVC (CRT), was shown to cross the blood brain barrier (BBB) and accumulate at high levels in GBM tissues. In this study, we synthesized a TfR 1-targeted near-infrared fluorescent (NIRF) probe, Cy5-CRT, for identifying the GBM tissue margin in mouse models. METHODS: We initially confirmed the overexpression of TfR 1 in GBM and the tumor-specific homing ability of Cy5-CRT in subcutaneous and orthotopic GBM mouse models. We then examined the feasibility of Cy5-CRT for identifying the tumor margin in orthotopic GBM xenografts. Finally, we compared Cy5-CRT with the clinically used fluorescein sodium in identifying tumor margins. RESULTS: Cy5-CRT specifically accumulated in GBM tissues and detected the tumor burden with exceptional contrast in mice with orthotopic GBM, enabling fluorescence-guided GBM resection under NIRF live imaging conditions. Importantly, Cy5-CRT recognized the GBM tissue margin more clearly than fluorescein sodium. CONCLUSIONS: The TfR 1-targeted optical probe Cy5-CRT specifically differentiates tumor tissues from the surrounding normal brain with high sensitivity, indicating its potential application for the precise surgical removal of GBM.
Asunto(s)
Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Glioma/metabolismo , Glioma/patología , Microscopía Fluorescente/métodos , Imagen Óptica/métodos , Receptores de Transferrina/metabolismo , Animales , Carbocianinas , Línea Celular Tumoral , Modelos Animales de Enfermedad , Fluoresceína , Colorantes Fluorescentes , Ratones , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
OBJECTIVE: To determine the reproducibility of quantitative computed tomography perfusion (CTP) parameters generated using different post-processing methods and identify the relative impact of subjective factors on the robustness of CTP parameters in acute ischemic stroke (AIS). MATERIALS AND METHODS: A total of 80 CTP datasets from patients with AIS or transient ischemic attack (TIA) were retrospectively post-processed by two observers using different regions of interest (ROI) types, input models, and software. The CTP parameters were derived for 10 parenchymal ROIs. The intra-class correlation coefficients (ICCs) were used to assess the reproducibility of the CTP parameters for various post-processing methods. The Spearman correlation test was used to detect potential relationships between software and input models. RESULTS: The ICCs with 95% confidence intervals (CIs) were 0.94 (0.93-0.96), 0.94 (0.92-0.96), 0.82 (0.79-0.86), and 0.87 (0.85-0.90) for inter-reader agreement by using elliptic ROI, irregular ROI, single-input model, and dual-input model, respectively. The ICCs with 95% CI were 0.98 (0.98-0.98), 0.46 (0.43-0.50), and 0.25 (0.20-0.30) for inter-ROI type, inter-input model, and inter-software agreement, respectively. CONCLUSIONS: Although the CTP parameters were stable when measured using different readers with different ROI types, they varied for different input models and software. The standardization of CTP post-processing is essential to reduce variability of CTP values. KEY POINTS: ⢠The CTP parameters derived by different readers with different ROI types have agreements that range from good to excellent. ⢠The CTP parameters derived from different input models and software programs have poor agreement but significant correlations.
Asunto(s)
Isquemia Encefálica/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Circulación Cerebrovascular , Imagen de Perfusión , Tomografía Computarizada por Rayos X , Anciano , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Proyectos de Investigación , Estudios Retrospectivos , Programas Informáticos , Accidente Cerebrovascular/diagnóstico por imagenRESUMEN
Glioblastoma multiforme (GBM) is the most common and aggressive malignant primary tumor in the central nervous system. One of the most widely used chemotherapeutic drugs for GBM is temozolomide, which is a DNA-alkylating agent and its efficacy is dependent on MGMT methylation status. Little progress in improving the prognosis of GBM patients has been made in the past ten years, urging the development of more effective molecular targeted therapies. Hyper-activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway is frequently found in a variety of cancers including GBM, and it plays a central role in the regulation of tumor cell survival, growth, motility, angiogenesis and metabolism. Numerous PI3K inhibitors including pan-PI3K, isoform-selective and dual PI3K/mammalian target of rapamycin (mTOR) inhibitors have exhibited favorable preclinical results and entered clinical trials in a range of hematologic malignancies and solid tumors. Furthermore, combination of inhibitors targeting PI3K and other related pathways may exert synergism on suppressing tumor growth and improving patients' prognosis. Currently, only a handful of PI3K inhibitors are in phase I/II clinical trials for GBM treatment. In this review, we focus on the importance of PI3K/Akt pathway in GBM, and summarize the current development of PI3K inhibitors alone or in combination with other inhibitors for GBM treatment from preclinical to clinical studies.
Asunto(s)
Antineoplásicos/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/metabolismo , Glioblastoma/tratamiento farmacológico , Glioblastoma/metabolismo , Terapia Molecular Dirigida , Inhibidores de las Quinasa Fosfoinosítidos-3 , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Antineoplásicos/química , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/patología , Catálisis , Estudios Clínicos como Asunto , Descubrimiento de Drogas , Evaluación Preclínica de Medicamentos , Glioblastoma/mortalidad , Glioblastoma/patología , Humanos , Isoenzimas , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/efectos adversos , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/metabolismo , Resultado del TratamientoRESUMEN
Preoperative prognostic nutritional index (PNI) has been widely demonstrated to predict survival of patients with malignant tumors. Its utility in predicting outcomes in patients with high-grade gliomas (HGG) remains undefined. A retrospective study of 188 HGG patients was conducted. An optimal PNI cut-off value was applied to stratify patients into high PNI (≥52.55, n = 78) and low PNI (<52.55, n = 110) groups. Univariate and multivariate analysis was performed to identify prognostic factors associated with overall survival (OS) and progression free survival (PFS). The resulting prognostic models were externally validated using a demographic-matched cohort of 130 HGG patients. In the training set, PNI value was negatively correlated with age (p = 0.027) and tumor grade (p = 0.048). Both PFS (8.27 vs. 20.77 months, p < 0.001) and OS (13.57 vs. 33.23 months, p < 0.001) were significantly worse in the low PNI group. Strikingly, patients in high PNI group had a 52% decrease in the risk of tumor progression and 55% decrease of death relative to low PNI. Multivariate analysis further demonstrated PNI as an independent predictor for PFS (HR = 0.62, 95% CI 0.43-0.87) and OS (HR = 0.56, 95% CI 0.38-0.80). The PNI retained independent prognostic value in the validation set for both PFS (p = 0.013) and OS (p = 0.003). On subgroup analysis by tumor grade and treatment modalities, both PFS and OS were better for the patients with high PNI. The PNI is a potentially valuable preoperative marker for the survival of patients following HGG resection.
Asunto(s)
Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/mortalidad , Glioma/diagnóstico , Glioma/mortalidad , Evaluación Nutricional , Adolescente , Adulto , Anciano , Índice de Masa Corporal , Neoplasias Encefálicas/cirugía , Niño , Preescolar , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Glioma/cirugía , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Adulto JovenRESUMEN
Gliomas are a common adult central nervous system tumor, and glioblastoma (GBM), which has a poor prognosis, is the most lethal of all gliomas. The overall survival of GBM patients is only 12-14 months after diagnosis. With progress in the precision of personal medication, therapeutic options for various tumors have become gradually dependent on the molecular profiles of patients. GBM is one of the tumors in which treatment response relies largely on the molecular characteristics of the tumor. Therefore, awareness of the genetic background of each patient will help decision-making regarding the best treatment strategy to use. In this review, a novel molecular classification of gliomas based on recent findings of their genetic characteristics is introduced. Representative molecular markers, such as IDH1 mutation, 1p19q co-deletion, MGMT promoter methylation and EGFRvIII amplification, are described. Furthermore, the development of non-coding RNAs and omics studies of GBM are briefly discussed. Finally, a novel concept for non-invasive detection that could facilitate both diagnosis and treatment monitoring is presented. There is no doubt that the use of molecular profiling by biomarkers will indeed improve the overall survival and quality of life of GBM patients.
Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias Encefálicas/genética , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Receptores ErbB/genética , Glioma/genética , Isocitrato Deshidrogenasa/genética , Proteínas Supresoras de Tumor/genética , Neoplasias Encefálicas/clasificación , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patología , Deleción Cromosómica , Cromosomas Humanos Par 1 , Metilación de ADN , Expresión Génica , Glioma/clasificación , Glioma/diagnóstico , Glioma/patología , Humanos , Medicina de Precisión , Pronóstico , Regiones Promotoras GenéticasAsunto(s)
Betacoronavirus/aislamiento & purificación , Neoplasias Encefálicas/cirugía , Infecciones por Coronavirus/complicaciones , Transmisión de Enfermedad Infecciosa/prevención & control , Personal de Salud/normas , Procedimientos Neuroquirúrgicos/normas , Neumonía Viral/complicaciones , Guías de Práctica Clínica como Asunto/normas , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/virología , COVID-19 , Niño , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/transmisión , Humanos , Masculino , Pandemias/prevención & control , Equipo de Protección Personal , Neumonía Viral/prevención & control , Neumonía Viral/transmisión , SARS-CoV-2 , Oncología Quirúrgica/normasRESUMEN
BACKGROUND: Although the incidence of glioma is relatively low, it is the most malignant tumor of the central nervous system. The prognosis of high-grade glioma patient is very poor due to the difficulties in complete resection and resistance to radio-/chemotherapy. Therefore, it is worth investigating the molecular mechanisms involved in glioma drug resistance. MicroRNAs have been found to play important roles in tumor progression and drug resistance. Our previous work showed that miR-181b is involved in the regulation of temozolomide resistance. In the current study, we investigated whether miR-181b also plays a role in antagonizing the effect of teniposide. METHODS: MiR-181b expression was measured in 90 glioma patient tissues and its relationship to prognosis of these patients was analyzed. Cell sensitivity to teniposide was tested in 48 primary cultured glioma samples. Then miR-181b stably overexpressed U87 cells were generated. The candidate genes of miR-181b from our previous study were reanalyzed, and the interaction between miR-181b and target gene MDM2 was confirmed by dual luciferase assay. Cell sensitivity to teniposide was detected on miR-181b over expressed and MDM2 down regulated cells. RESULTS: Our data confirmed the low expression levels of miR-181b in high-grade glioma tissues, which is related to teniposide resistance in primary cultured glioma cells. Overexpression of miR-181b increased glioma cell sensitivity to teniposide. Through target gene prediction, we found that MDM2 is a candidate target of miR-181b. MDM2 knockdown mimicked the sensitization effect of miR-181b. Further study revealed that miR-181b binds to the 3'-UTR region of MDM2 leading to the decrease in MDM2 levels and subsequent increase in teniposide sensitivity. Partial restoration of MDM2 attenuated the sensitivity enhancement by miR-181b. CONCLUSIONS: MiR-181b is an important positive regulator on glioma cell sensitivity to teniposide. It confers glioma cell sensitivity to teniposide through binding to the 3'-UTR region of MDM2 leading to its reduced expression. Our findings not only reveal the novel mechanism involved in teniposide resistance, but also shed light on the optimization of glioma treatment in the future.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Glioma/tratamiento farmacológico , MicroARNs/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/antagonistas & inhibidores , Tenipósido/farmacología , Biomarcadores de Tumor/genética , Línea Celular Tumoral , Resistencia a Antineoplásicos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Glioma/genética , Glioma/patología , Humanos , MicroARNs/genética , Pronóstico , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Células Tumorales CultivadasRESUMEN
Anti-angiogenic therapy has shown promising but insufficient efficacy on gliomas. Recent studies suggest that vasculogenic mimicry (VM), or the formation of non-endothelial, tumor-cell-lined microvascular channels, occurs in aggressive tumors, including gliomas. There is also evidence of a physiological connection between the endothelial-lined vasculature and VM channels. Tumor cells, by virtue of their high plasticity, can form vessel-like structures themselves, which may function as blood supply networks. Our previous study on gliomas showed that microvessel density was comparably less in VM-positive tumors than in VM-negative tumors. Thus, VM may act as a complement to ensure tumor blood supply, especially in regions with less microvessel density. Patients with VM-positive gliomas survived a shorter period of time than did patients with VM-negative gliomas. Although the detailed molecular mechanisms for VM are not fully understood, glioma stem cells might play a key role, since they are involved in tumor tissue remodeling and contribute to neovascularization via transdifferentiation. In the future, successful treatment of gliomas should involve targeting both VM and angiogenesis. In this review, we summarize the progress and challenges of VM in gliomas.
Asunto(s)
Neoplasias Encefálicas/irrigación sanguínea , Glioma/irrigación sanguínea , Neoplasias/irrigación sanguínea , Neovascularización Patológica , Antígenos CD34/metabolismo , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/terapia , Glioma/patología , Glioma/terapia , Humanos , Metaloproteinasa 2 de la Matriz/metabolismo , Microcirculación , Neoplasias/patología , Neoplasias/terapia , Células Madre Neoplásicas/patología , PronósticoRESUMEN
O6-methylguanine DNA methyltransferase (MGMT) can remove DNA alkylation adducts, thereby repairing damaged DNA and contributing to the drug resistance of gliomas to alkylating agents. In addition, glioma stem-like cells (GSCs) have been demonstrated to be involved in the recurrence and treatment resistance of gliomas. In this study, we aimed to investigate MGMT expression and regulatory mechanisms in GSCs and the association of MGMT with temozolomide (TMZ) sensitivity. GSCs were enriched from one MGMT-positive cell line (SF-767) and 7 MGMT-negative cell lines (U251, SKMG-4, SKMG-1, SF295, U87, MGR1, and MGR2) through serum-free clone culture. GSCs from the U251G, SKMG-4G, SF295G, and SKMG-1G cell lines became MGMT-positive, but those from the U87G, MGR1G, and MGR2G cell lines remained MGMT-negative. However, all the GSCs and their parental glioma cell lines were positive for nuclear factor-κB (NF-κB). In addition, GSCs were more resistant to TMZ than their parental glioma cell lines (P < 0.05). However, there was no significant difference in the 50% inhibition concentration (IC50) of TMZ between MGMT-positive and MGMT-negative GSCs (P > 0.05). When we treated the MGMT-positive GSCs with TMZ plus MG-132 (an NF-κB inhibitor), the antitumor activity was significantly enhanced compared to that of GSCs treated with TMZ alone (P <0.05). Furthermore, we found that MGMT expression decreased through the down-regulation of NF-κB expression by MG-132. Our results show that MG-132 may inhibit NF-κB expression and further decrease MGMT expression, resulting in a synergistic effect on MGMT-positive GSCs. These results indicate that enhanced MGMT expression contributes to TMZ resistance in MGMT-positive GSCs.
Asunto(s)
Dacarbazina/análogos & derivados , Glioma/patología , Leupeptinas/farmacología , FN-kappa B , Células Madre Neoplásicas/metabolismo , O(6)-Metilguanina-ADN Metiltransferasa/metabolismo , Antineoplásicos Alquilantes/farmacología , Línea Celular Tumoral , Dacarbazina/farmacología , Resistencia a Antineoplásicos , Sinergismo Farmacológico , Glioma/metabolismo , Humanos , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , TemozolomidaRESUMEN
BACKGROUND: Nasopharyngeal carcinoma (NPC) is a frequent head and neck cancer in southern China and Southeast Asia. The majority of NPC patients are managed by radiation oncologists, medical oncologists and head and neck surgeons. Actually, neurosurgical interventions are warranted under specific circumstances. In this article, we described our experience as neurosurgeons in the management of NPC patients. METHODS: Medical records of NPC patients who received neurosurgical procedure at Sun Yat-sen University Cancer Center were reviewed. RESULTS: Twenty-seven patients were identified. Among 27 cases, neurosurgical procedures were performed in 18 (66.7%) with radiation-induced temporal necrosis, 2 (7.4%) with radiation-induced sarcoma, 4 (14.8%) with synchronous NPC with primary brain tumors, 2 (7.4%) with recurrent NPC involving skull base, and 1 (3.7%) with metachronous skull eosinophilic granuloma, respectively. The diagnosis is challenging in specific cases and initial misdiagnoses were found in 6 (22.2%) patients. CONCLUSIONS: For NPC patients with intracranial or skull lesions, the initial diagnosis can be occasionally difficult because of the presence or a history of NPC and related treatment. Unawareness of these entities can result in misdiagnosis and subsequent improper treatment. Neurosurgical interventions are necessary for the diagnosis and treatment for these patients.
Asunto(s)
Neoplasias Encefálicas/cirugía , Neoplasias Nasofaríngeas/cirugía , Recurrencia Local de Neoplasia/cirugía , Procedimientos Neuroquirúrgicos , Traumatismos por Radiación/cirugía , Sarcoma/cirugía , Adulto , Anciano , Neoplasias Encefálicas/etiología , Neoplasias Encefálicas/patología , Carcinoma , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/complicaciones , Neoplasias Nasofaríngeas/radioterapia , Necrosis , Recurrencia Local de Neoplasia/etiología , Recurrencia Local de Neoplasia/patología , Pronóstico , Traumatismos por Radiación/etiología , Traumatismos por Radiación/patología , Sarcoma/etiología , Sarcoma/patologíaAsunto(s)
Hemangioma Cavernoso , Dolor/etiología , Neoplasias de la Médula Espinal , Raíces Nerviosas Espinales/diagnóstico por imagen , Hemangioma Cavernoso/complicaciones , Hemangioma Cavernoso/diagnóstico por imagen , Hemangioma Cavernoso/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neoplasias de la Médula Espinal/complicaciones , Neoplasias de la Médula Espinal/diagnóstico por imagen , Neoplasias de la Médula Espinal/cirugía , Raíces Nerviosas Espinales/patologíaRESUMEN
OBJECTIVE: To explore the survival of newly diagnosed malignant gliomas patients on combined modality therapy of surgery, radiotherapy and chemotherapy. METHODS: The data of 122 newly diagnosed malignant glioma patients on combined modality therapy at our center between 2000 and 2010 were retrospectively reviewed and analyzed. The median age was 40 years old (range: 5 - 75) and median Karnofsky performance status score (KPS) 80 (range: 60 - 100). Combined modality therapy consisted of surgery (maximal safety tumor resection), followed by fractionated focal irradiation for a total dose of 54 - 60 Gy and then 4 - 6 cycles of adjuvant chemotherapy including temozolomide or nitrosourea-based regimens or other ones without temozolomide and nitrosourea. The overall and progression-free survivals were analyzed by the Kaplan-Meier method and the influencing factors screened by Cox proportional hazard model. RESULTS: There were grade IV (n = 70) and grade III (n = 52). The median survival periods were 17.0 months for grade IV patients and 36.0 months for grade III ones. The 2, 3, 4 and 5-year survival rates were 32.0% vs 64.8%, 19.6% vs 47.8%, 11.8% vs 32.0% and 5.9% vs 25.4% (P < 0.01) for grades IV and III patients respectively. The median progression-free survivals were 9.0 vs 12.0 months and 1, 2 and 3-year progression-free survival rates 30.8% vs 50.0%, 12.3% vs 31.4% and 9.2% vs 17.7% (P < 0.01) respectively. Multivariate analysis revealed that histologic type was an independent prognostic factor. CONCLUSION: Combined modality therapy of surgery, adjuvant radiotherapy and chemotherapy may improve the survival of patients with malignant gliomas.