PubMed HealthSearch

SEARCH · PubMed Health

Results for “gliomas”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Scanning electron microscopy of malignant gliomas. A comparative study of glioma cells in smear preparations and in tissue culture.

Smear preparations from 15 malignant gliomas, 2 metastatic carcinomas and from normal brain were examined by scanning electron microscopy. Tissue culture preparations from malignant gliomas were also studied. In the better differentiated areas of gliomas, the cells in smears were stellate with multiple long interweaving processes 0.25--1.3 micrometer in diameter which could be distinguished from myelinated nerve fibers (1.3--5 micrometer) and from fibrin (0.08--0.3 micrometer) by their thickness and arrangement in the tissue. The relationship of glial processes to blood vessels within the tumour was well demonstrated in smears. Metastatic carcinoma cells lacked the processes seen in glioma cell smears and did not show the same relationship to blood vessels. The more anaplastic glioma cells had fewer processes and ovoid cell bodies covered with surface ruffles and microvilli similar to the cell membrane projections in the nuclear regions of glioma cells in culture. The relationship of the surface morphology of glioma cells in smears to the known invasive nature of these tumours is discussed.

Brain Neoplasms

Lactic dehydrogenase in ethylnitrosourea-induced rat gliomas. Total lactic dehydrogenase activity and isozymes in autochthonous gliomas and cloned transplantable astrocytomas.

Total lactic dehydrogenase (LDH) levels and LDH isozyme patterns were measured in homogenates of 12 autochthonous ethylnitrosourea-induced rat gliomas and 5 cloned rat astrocytoma cell lines maintained in culture and transplanted to brain or flank sites in syngeneic hosts. The total LDH values in the autochthonous gliomas did not differ appreciably from normal brain controls, but the proportions of the cathodal isozymes, LDH4 and LDH5, were increased to a degree similar to that reported by others in spontaneous human malignant astrocytic gliomas. The cloned astrocytoma lines, both in vitro and in transplants at intracerebral or subcutaneous sites, commonly demonstrated elevated total LDH values and, without exception, showed a preponderance of isozymes, LDH4 and LDH5, that was distinctly more marked than in autochthonous tumors. Especially in cultured and transplanted rat gliomas, these findings suggest that astrocytic tumor cells maintain energy supplies by utilizing anaerobic glycolysis in relatively hypoxic environments. These data further underscore the need to develop laboratory brain tumor models for use in therapy trials that not only retain the convenience and predictability of transplantable gliomas but also approximate closely the metabolic properties of human spontaneous gliomas.

Animals

Alanine inhibition of pyruvate kinase in gliomas and meningiomas. A diagnostic tool in surgery for gliomas?

In gliomas a shift was found in the composition of enzymes, manifested by abnormal inhibition of pyruvate kinase by alanine. This study demonstrates the appearance of the MII-type isoenzyme in various gliomas. This MII type is also found in meningiomas but not in normal brain tissue. The method of enzyme examination described may be valuable as a diagnostic aid in the surgery of gliomas.

Alanine

Reactive glioma in intracranial sarcoma: a form of mixed sarcoma and glioma ("sarcoglioma"): report of eight cases.

The clinicopathologic features of eight new cases of combined intracranial sarcoma and glioma are described. This type of mixed cerebral tumor is histologically characterized by a peripheral distribution of the gliomatous elements in relation to a more centrally situated meningeal or intracerebral sarcoma, and by the frequent presence of gradual transitions from reactive to frankly neoplastic astrocytes. In six of the eight cases, the additional development of either infiltrating astrocytoma or frank glioblastoma in the adjacent brain was demonstrated; this was interpreted as a further expression of malignant glial reaction. It is suggested that these tumors be termed "sarcogliomas" to distinguish them from the type of mixed glioma and sarcoma that has recently been redesignated "gliosarcoma."

Adolescent

Two separate membrane-bound antigens on human glioma cells in tissue culture detected with sera from glioma patients by immunofluorescence.

Sera from patients with malignant and benign gliomas, as well as sera from healthy donors, were tested by indirect immunofluorescence to detect antibodies against antigens on the membrane of glioblastoma, astrocytoma, reactive perimetastatic glia, normal glia and fibroblasts in tissue culture. Sera from glioblastoma patients reacted with glioblastoma, astrocytoma and reactive glial cells; they were negative on normal glia and on fibroblasts, whereas sera from astrocytoma patients were unreactive. Sera from control patients were positive in 7 out of 15 cases, although some differences were noted in the pattern of reaction. Absorption with astrocytoma powder, with glioblastoma and reactive glial cells indicated that all the positive cell lines expressed an astrocytoma-associated antigen "A", while only glioblastoma lines and reactive glial line shared a supplementary antigen "G". Neither of these 2 antigens seemed to be present in significant amount in normal brain, since the positive reactions could not be abolished by absorption with normal brain powder. The relationship between these 2 antigens and the process of increasing malignancy in gliomas is briefly discussed.

Antibodies, Neoplasm

Synergism between BCNU and irradiation in the treatment of anaplastic gliomas. An in vivo study using the avian sarcoma virus-induced glioma model.

The therapeutic effects of irradiation, BCNU, or combined irradiation and BCNU were studied in the avian sarrcoma virus (ASV)-induced glioma model in rats. Whole-head orthovoltage radiation therapy was given in six equal fractions over 2 weeks, and BCNU was administered intraperitoneally as a single dose of 10 mg/kg. Two series of experiments were performed in order to duplicate the results. In Series I, the median survival times of the experimental groups, in days after randomization were as follows: control group (no treatment), 69; group receiving 200 rads, 84 (p less than 0.05); group receiving BCNU, 80.5 (p less than 0.1); and group receiving 2000 rads + BCNU, 112 (p less than 0.001). In Series 2, the median survival times were: control group, 73.5; group receiving 2300 rads, 85 (p less than 0.01); group receiving BCNU, 92.5 (p less than 0.025); and group receiving 2300 rads + BCNU, 123.5 (p less than 0.001). In both series, combined therapy was significantly better than either radiation or BCNU alone. This is the first time that a synergistic effect of BCNU and irradiation has been reported in an in vivo brain-tumor model and supports the clinical use of this combination in the treatment of malignant gliomas.

Animals

Boron neutron capture therapy of cerebral gliomas. II. Utilization of the blood-brain barrier and tumor-specific antigens for the selective concentration of boron in gliomas.

The use of the blood-brain barrier and of tumor-specific antibodies to concentrate boron selectivity in gliomas for neutron capture therapy is considered experimentally and theoretically. The time-dependent concentration of two anionic boranes, B12 H11 SH2- and B12 H11 SOSB12 H114-, in the blood, brain, and tumor of rats bearing a tumor of gliomatous origin is reported. The rate of clearance of each anionic borane from the blood is correlated with the fraction of non-protein bound anion in the plasma. The use of antibodies to carry therapeutical useful amounts of boron to tumor-specific or tumor-associated antigens on the tumor cell surface will require different numbers of boron atoms bound per antibody depending on several immunological and physical parameters. Calculations using published values of antibody-antigen association constants and of cell surface antigen densities predict that in order to obtain 10mug 10B/g tumor from 10 to over 10,000 boron-10 atoms will have to be bound per tumor antigenic site.

Animals

POFUT1 Serves as an Independent Prognostic Factor and Therapeutic Target by Activating the PI3K/AKT Pathway in Glioma.

OBJECTIVE: Protein O-fucosyltransferase 1 (POFUT1) has been implicated in several malignancies, but its functional and prognostic significance in glioma remains insufficiently defined. This study evaluated whether POFUT1 expression is associated with glioma progression, patient outcome, and PI3K/AKT pathway activity. METHODS: Public glioma transcriptome datasets from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) were analyzed and compared with clinical samples collected from 123 glioma patients. POFUT1 protein levels in clinical specimens were determined by immunohistochemical staining, and its association with patient outcome was analyzed using survival curves. In vitro, glioma cell growth, motility, and invasiveness were examined using MTT and Transwell assays. The effect of POFUT1 on tumor formation was further tested in a subcutaneous xenograft model. RNA sequencing, KEGG pathway enrichment, and pharmacological inhibition were then used to explore the mechanism linking POFUT1 to PI3K/AKT signaling. RESULTS: POFUT1 expression was higher in glioma than in normal brain tissue and increased with tumor grade. Patients with high POFUT1 levels had shorter overall survival, and multivariate Cox analyses supported POFUT1 as an independent prognostic indicator. Incorporating POFUT1 into a nomogram improved prediction of 1-, 3-, and 5-year survival. Functionally, POFUT1 knockdown reduced glioma cell growth, motility, invasion, and xenograft expansion, whereas POFUT1 overexpression produced the opposite phenotype. Transcriptomic and protein analyses indicated that POFUT1 enhanced PI3K/AKT signaling. The PI3K inhibitor LY294002 weakened the tumor-promoting effects caused by POFUT1 overexpression. CONCLUSION: POFUT1 as a key driver of glioma malignancy, predominantly through activating the PI3K-AKT signaling pathway. These findings highlight POFUT1 as a promising novel therapeutic target for aggressive glioma.

Glioma

NR2F6 regulates Temozolomide resistance in glioma via the E2F2-PARP1 pathway.

BACKGROUND: Glioma is the most common primary malignant brain tumor in adults. Temozolomide (TMZ) represents a standard-of-care chemotherapeutic agent in glioblastoma (GBM). However, the development of drug resistance constitutes a significant hurdle in the treatment of malignant glioma. Elucidating the mechanisms of temozolomide (TMZ) resistance in glioma is of critical clinical importance for improving patient prognosis and developing novel therapeutic strategies. METHODS: We obtained RNA sequencing (RNA-seq) data of 648 glioma samples from The Cancer Genome Atlas (TCGA) and 325 samples from the Chinese Glioma Genome Atlas (CGGA) as study cohorts. Additionally, we validated the expression characteristics of the NR2F6 gene in our in-house cohort of glioma patients. Furthermore, we investigated the potential mechanism of NR2F6 in TMZ resistance in glioma by constructing TMZ-resistant cell lines in vitro. Statistical analyses and graphical work were primarily performed using R language and GraphPad Prism software. RESULTS: We observed a significant upregulation of NR2F6 expression in high-grade gliomas, which is associated with an unfavorable prognosis in patients. Concurrently, our findings revealed a significant upregulation of NR2F6 in drug-resistant cells, which induced TMZ resistance in glioma cells via the E2F2-PARP1 axis. CONCLUSION: In brief, NR2F6, as a nuclear transcription factor, enhances the transcription of E2F2.The increased expression of E2F2 enhances PARP1 expression, which in turn facilitates TMZ-mediated DNA damage repair, thereby diminishing glioma sensitivity to TMZ.

Journal Article

Genetic association between epilepsy and gliomas: Insights from Mendelian randomization and single-cell transcriptomic analyses.

BACKGROUND: Seizures are prevalent in glioma patients, especially in those with low-grade gliomas. The interaction between gliomas and epilepsy involves complex biological mechanisms that are not fully understood. METHODS: We collected Genome-Wide Association Study data for epilepsy and gliomas, performed differential expression analysis, and conducted Gene Ontology (GO) enrichment analysis on the identified genes. Single-cell RNA sequencing data (scRNA-seq) from GSE221534 dataset in Gene Expression Omnibus (GEO) were used to analyze cell-cell interactions within glioma samples from patients with and without epilepsy. RESULTS: Mendelian Randomization (MR) analysis revealed significant associations between genetic variants related to epilepsy and glioma risk, suggesting a potential causal relationship, especially in astrocytomas. Differential expression analysis identified epilepsy-related genes that were significantly upregulated in astrocytoma tissues compared to normal brain tissues. GO enrichment analysis indicated that these genes are involved in critical biological processes such as neurogenesis and cellular signaling. The scRNA-seq analysis showed, compared to non-epileptic samples, glioma stem cells, microglia, and NK cells are increased in the core regions of astrocytomas in epileptic patients. Additionally, intercellular communication between tumor cells and other non-tumor cells is markedly enhanced in astrocytoma samples from epileptic patients. CONCLUSION: This study provides evidence of a genetic association between epilepsy and gliomas and elucidates the biological mechanisms through which epilepsy may influence glioma progression.

Humans

Systematic decoding of functional enhancer connectomes and risk variants in human glioma.

Genetic and epigenetic variations contribute to the progression of glioma, but the mechanisms underlying these effects, particularly for enhancer-associated genetic variations in non-coding regions, still remain unclear. Here we performed high-throughput CRISPR interference screening to identify pro-tumour enhancers in glioma cells. By integrating genome-wide H3K27ac HiChIP data, we identified the target genes of these pro-tumour enhancers and revealed the essential role of enhancer connectomes in promoting glioma progression. Through systematic analysis of enhancers carrying glioma risk-associated single-nucleotide polymorphisms (SNPs), we found that these SNPs can promote glioma progression through the enhancer connectome. Using CRISPR-Cas9-mediated enhancer interference and SNP editing, we demonstrated that glioma-specific enhancer carrying the risk SNP rs2297440 regulates SOX18 expression by specifically recruiting transcription factor MEIS1 binding, thereby contributing to glioma progression. Our study sheds light on the molecular mechanisms underlying glioma susceptibility and provides potential therapeutic targets to treat glioma.

Humans

Integrated bioinformatics analysis and experimental validation reveal the relationship between ALOX5AP and the prognosis and immune microenvironment in glioma.

BACKGROUND: Treatment of gliomas, the most prevalent primary malignant neoplasm of the central nervous system, is challenging. Arachidonate 5-lipoxygenase activating protein (ALOX5AP) is crucial for converting arachidonic acid into leukotrienes and is associated with poor prognosis in multiple cancers. Nevertheless, its relationship with the prognosis and the immune microenvironment of gliomas remains incompletely understood. METHODS: The differential expression of ALOX5AP was evaluated based on public Databases. Kaplan-Meier, multivariate Cox proportional hazards regression analysis, time-dependent receiver operating characteristic, and nomogram were used to estimate the prognostic value of ALOX5AP. The relationship between ALOX5AP and immune infiltration was calculated using ESTIMATE and CIBERSORT algorithms. Relationships between ALOX5AP and human leukocyte antigen molecules, immune checkpoints, tumor mutation burden, TIDE score, and immunophenoscore were calculated to evaluate glioma immunotherapy response. Single gene GSEA and co-expression network-based GO and KEGG enrichment analysis were performed to explore the potential function of ALOX5AP. ALOX5AP expression was verified using multiplex immunofluorescence staining and its prognostic effects were confirmed using a glioma tissue microarray. RESULT: ALOX5AP was highly expressed in gliomas, and the expression level was related to World Health Organization (WHO) grade, age, sex, IDH mutation status, 1p19q co-deletion status, MGMTp methylation status, and poor prognosis. Single-cell RNA sequencing showed that ALOX5AP was expressed in macrophages, monocytes, and T cells but not in tumor cells. ALOX5AP expression positively correlated with M2 macrophage infiltration and poor immunotherapy response. Immunofluorescence staining demonstrated that ALOX5AP was upregulated in WHO higher-grade gliomas, localizing to M2 macrophages. Glioma tissue microarray confirmed the adverse effect of ALOX5AP in the prognosis of glioma. CONCLUSION: ALOX5AP is highly expressed in M2 macrophages and may act as a potential biomarker for predicting prognosis and immunotherapy response in patients with glioma.

Humans

m6A regulator-based molecular classification and hub genes associated with immune infiltration characteristics and clinical outcomes in diffuse gliomas.

BACKGROUND: m6A methylation modification is a new regulatory mechanism involved in tumorigenesis and tumor-immunity interaction. However, its impact on glioma immune microenvironment and clinical outcomes remains unclear. METHODS: Comprehensive expression profiles of 18 m6A regulators were used to identify molecular subtypes exhibiting distinct m6A modification patterns in 1673 glioma samples sourced from public datasets. A multi-genes signature was constructed for predicting clinical outcomes and response to immunotherapy in glioma patients. Immunohistochemistry and cellular experiments were performed for validation. RESULTS: Two m6A subtypes of gliomas were identified. The m6A-low-risk subtype was characterized by paucity of immune infiltrates; While the m6A-high-risk subtype had higher abundances of multiple immune cells including lymphocyte and macrophage as well as increased expression of PD-L1, corresponding to an immunosuppressive phenotype. The m6A-high-risk subtype had poorer survival than the m6A-low-risk subtype in both the glioblastoma and lower grade gliomas cohorts. Eight m6A-related hub genes of high prognostic significances were identified and selected for developing a scoring signature termed as m6Ascore. Elevated m6Ascore indicated worse survival for glioma patients under standard care, but showed enhanced response to immunotherapy. Moreover, we demonstrated that overexpression of FTO, a m6A demethylase, inhibited the expressions of m6A-related hub genes (PTX3, SPAG4), impaired glioma cell viability and reduced macrophage chemotaxis. CONCLUSION: This work develops an immune- and clinical-relevant m6A subtyping and a scoring model, which enhances our understanding of the role of m6A modification in regulating immune infiltration microenvironment in gliomas and helps to identify patients who are more likely to benefit from immunotherapy.

Humans

Genetic variants in IGF2BP family genes are associated with glioma risk in Chinese children.

BACKGROUND: Glioma is a highly prevalent malignant tumor of the central nervous system in children and is driven by complex genetic and environmental factors. IGF2BP family genes (IGF2BP1, IGF2BP2, and IGF2BP3) encode critical RNA epigenetic "readers" that participate in posttranscriptional gene regulation and modulate various cellular processes. However, the contributions of these gene variants to glioma risk remain unclear. METHODS: A multicenter case-control study was conducted, enrolling 360 patients with glioma and 547 cancer-free controls. Genotyping of 11 potentially functional polymorphisms within IGF2BP family genes was performed using the TaqMan assay. Unconditional logistic regression models were employed to estimate odds ratios and 95% confidence intervals. Furthermore, expression quantitative trait loci (eQTL) and The Cancer Genome Atlas (TCGA) clinical database analyses were conducted to investigate the potential regulatory mechanisms and clinical significance of the identified variants. RESULTS: We found that the IGF2BP1 rs2270575 polymorphism was significantly associated with a decreased risk of glioma. Conversely, the IGF2BP2 rs17289925 and rs7646419 polymorphisms were linked to increased glioma risk. Stratification and cumulative effect analyses revealed that harboring multiple risk genotypes of IGF2BP1 or IGF2BP2 substantially increased&#xa0;glioma susceptibility. This cumulative risk was especially notable among males, younger children (<&#x2009;60&#xa0;months), and patients diagnosed with early-stage (I&#x2009;+&#x2009;II) tumors. Additionally, eQTL and TCGA analyses revealed that the rs2270575 and rs7646419 alleles correlated significantly with altered mRNA expression levels of CALCOCO2 and AC099661.1 (ENSG00000286086), respectively, which further correlated with favorable molecular subtypes (IDH mutation status) and WHO tumor grades. CONCLUSION: Genetic polymorphisms within IGF2BP family genes significantly modulate pediatric glioma susceptibility and have cumulative, subtype-specific, and age-dependent effects; thus, these genes may serve as promising noninvasive biomarkers for early risk stratification of childhood glioma.

Adolescent

FZD5 drives macrophage-mediated immunomodulation and predicts prognosis in glioma: evidence from single-cell sequencing.

BACKGROUND: Gliomas are highly malignant brain tumors characterized by an immunosuppressive microenvironment, which limits therapeutic efficacy and contributes to poor clinical outcomes. The WNT/&#x3b2;-catenin signaling pathway is critically involved in tumor progression, and FZD5, a key receptor within this pathway, may participate in immune regulation. However, its specific role and underlying mechanisms in glioma remain unclear. METHODS: RNA-seq and microarray datasets from the Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas (TCGA), together with single-cell RNA sequencing (scRNA-seq) datasets from GEO, were comprehensively analyzed. The Seurat package was used to identify macrophage-related clusters and mitophagy-associated pathways. Cox and LASSO regression analyses, along with a prognostic nomogram, were applied to evaluate the prognostic significance of FZD5. Immune infiltration, functional enrichment, and immunotherapy response analyses were conducted, followed by validation using spatial transcriptomics, immunohistochemistry, and in vitro assays. RESULTS: In bulk glioma transcriptomes, FZD5 emerged as an independent predictor of poor prognosis. Crucially, single-cell and spatial analyses revealed that the biologically significant FZD5 signal originated predominantly within tumor-associated macrophages (TAMs), where it colocalized with the M2 marker CD163. Consistently, elevated FZD5 levels correlated with increased myeloid infiltration and an immunosuppressive tumor microenvironment. Functionally, macrophage-expressed FZD5 was associated with mitophagy-related programs and promoted an M2-skewed phenotype, thereby enhancing glioma cell proliferation, migration, and invasion via macrophage-glioma crosstalk. CONCLUSION: FZD5 is a TAM-enriched marker in glioma tissues and a potential regulator of macrophage-associated immunosuppressive programs, supporting its utility as a prognostic biomarker and a candidate target for microenvironment-oriented interventions in glioma.

Humans

Glioma mutational signatures associated with haloalkane exposure are enriched in firefighters.

BACKGROUND: Glioma is the most common malignant primary brain tumor and is associated with significant morbidity and mortality. Modifiable risk factors remain unidentified. New advances in exposure assessment, genomic analyses, and statistical techniques permit more accurate evaluation of glioma risk associated with exogenous occupational or environmental exposures. METHODS: By using whole-exome sequencing data from matched germline and glioma tumor samples, the authors compared tumor mutational signatures for 17 persons with glioma and a documented occupational history of firefighting with those of 18 persons with glioma without an occupational history of firefighting. All 35 individuals were participants in the University of California, San Francisco Adult Glioma Study. RESULTS: There was a positive correlation among firefighters between the median number of sample variants attributable to single-base substitution signature 42, a single-base substitution mutational signature associated with haloalkane exposure (from the Catalogue of Somatic Mutational Signatures in Cancer) and firefighting years (p&#xa0;=&#xa0;.04; R2&#xa0;=&#xa0;0.29). Among nonfirefighters, the individuals with the highest number of median variants attributable to single-base substitution signature 42 also had occupations that possibly exposed them to haloalkanes, such as painting and being a mechanic. CONCLUSIONS: In summary, the authors identified gliomas that had mutational signatures associated with haloalkane exposure that were enriched in firefighters and other occupations.

Humans