Classification and Diagnosis of Adult Glioma: A Scoping Review

Epigenetic reprogramming and antitumor immune responses in gliomas: a systematic review

Gliomas, particularly glioblastoma, are among the most aggressive and treatment-resistant brain tumors. Their immunosuppressive tumor microenvironment (TME) and intrinsic molecular heterogeneity hinder effective therapeutic responses. Epigenetic dysregulation in gliomas significantly impacts tumor progression and immune evasion, presenting an opportunity for therapeutic intervention. This systematic review evaluates the role of epigenetic reprogramming in modulating antitumor immune responses in gliomas and explores its potential to enhance treatment outcomes. A comprehensive literature search across major databases, adhering to PRISMA guidelines, identified preclinical and clinical studies examining the effects of epigenetic therapies on glioma-associated immune modulation. Inclusion criteria focused on studies involving DNA methylation inhibitors, histone deacetylase inhibitors, chromatin remodelers, and non-coding RNA-based therapies. Key outcomes included immune activation, tumor progression, survival, and TME modulation. Among 22 included studies, epigenetic therapies demonstrated substantial efficacy in reprogramming the glioma immune landscape. DNA methylation inhibitors such as decitabine enhanced antigen presentation and immune recognition, while histone deacetylase inhibitors improved T-cell-mediated cytotoxicity. Non-coding RNA-targeted interventions disrupted immune suppression and facilitated immune cell infiltration. These strategies showed synergistic potential with immune checkpoint inhibitors, leading to tumor growth inhibition and improved survival in preclinical models. Epigenetic therapies hold promise in overcoming glioma-induced immune resistance by modulating immune escape mechanisms and reprogramming the TME. Their integration with existing treatment modalities, including immunotherapy, represents a transformative avenue for glioma management. Further clinical validation is warranted to optimize their therapeutic potential and safety.

The therapeutic effect of mRNA vaccines in glioma: a comprehensive review

INTRODUCTION

Glioma is the most common primary brain tumor, with glioblastoma being the most lethal type due to its heterogeneous and invasive nature of the cancer. Current therapies have low curative success and are limited to surgery, radiotherapy, and chemotherapy. More than 50% of patients become resistant to chemotherapy, and tumor recurrence occurs in most patients following an initial course of therapy. Therefore, developing novel, effective strategies for glioma treatment is essential. Cancer vaccines are novel therapies that demonstrate advantages over conventional methods and, therefore, may be promising options for treating glioma.

AREAS COVERED

This article provided a critical review of pre-clinical and clinical studies that explored appropriate tumor antigen candidates for developing mRNA vaccines and discussed their clinical application in glioma patients. Medline database, PubMed, and ClinicalTrials.gov were searched for glioma vaccine studies published before 2025 using related keywords.

EXPERT OPINION

mRNA vaccines are promising strategies for treating glioma because they are efficient, cost-beneficial, and have lower side effects than other types such as peptide or DNA-based vaccines.

Current Understanding of the Exosomes and Their Associated Biomolecules in the Glioblastoma Biology, Clinical Treatment, and Diagnosis

Glioblastoma is the most common and aggressive brain tumor with a low survival rate. Due to its heterogeneous composition, high invasiveness, and frequent recurrence after surgery, treatment success has been limited. In addition, due to the brain's unique immune status and the suppressor tumor microenvironment (TME), glioblastoma treatment has faced more challenges. Exosomes play a critical role in cancer metastasis by regulating cell-cell interactions that promote tumor growth, angiogenesis, metastasis, treatment resistance, and immunological regulation in the tumor microenvironment. This review explores the pivotal role of exosomes in the development of glioblastoma, with a focus on their potential as non-invasive biomarkers for prognosis, early detection and real-time monitoring of disease progression. Notably, exosome-based drug delivery methods hold promise for overcoming the blood-brain barrier (BBB) and developing targeted therapies for glioblastoma. Despite challenges in clinical translation, the potential for personalized exosome = -054321`therapies and the capacity to enhance therapeutic responses in glioblastoma, present intriguing opportunities for improving patient outcomes. It seems that getting a good and current grasp of the role of exosomes in the fight against glioblastoma would properly serve the scientific community to further their understanding of the related potentials of these biological moieties.

Tumors and their microenvironments: Learning from pediatric brain pathologies

Early clues to tumors and their microenvironments come from embryonic development. Here we review the literature and consider whether the embryonic brain and its pathologies can serve as a better model. Among embryonic organs, the brain is the most heterogenous and complex, with multiple lineages leading to wide spectrum of cell states and types. Its dysregulation promotes neurodevelopmental brain pathologies and pediatric tumors. Embryonic brain pathologies point to the crucial importance of spatial heterogeneity over time, akin to the tumor microenvironment. Tumors dedifferentiate through genetic mutations and epigenetic modulations; embryonic brains differentiate through epigenetic modulations. Our innovative review proposes learning developmental brain pathologies to target tumor evolution-and vice versa. We describe ways through which tumor pharmacology can learn from embryonic brains and their pathologies, and how learning tumor, and its microenvironment, can benefit targeting neurodevelopmental pathologies. Examples include pediatric low-grade versus high-grade brain tumors as in rhabdomyosarcomas and gliomas.

Understanding Neovascularization in Glioblastoma: Insights from the Current Literature

Glioblastomas (GBMs), among the most aggressive and resilient brain tumors, characteristically exhibit high angiogenic potential, leading to the formation of a dense yet aberrant vasculature, both morphologically and functionally. With these premises, numerous expectations were initially placed on anti-angiogenic therapies, soon dashed by their limited efficacy in concretely improving patient outcomes. Neovascularization in GBM soon emerged as a complex, dynamic, and heterogeneous process, hard to manage with the classical standard of care. Growing evidence has revealed the existence of numerous non-canonical strategies of angiogenesis, variously exploited by GBM to meet its ever-increasing metabolic demand and differently involved in tumor progression, recurrence, and escape from treatments. In this review, we provide an accurate description of each neovascularization mode encountered in GBM tumors to date, highlighting the molecular players and signaling cascades primarily involved. We also detail the key architectural and functional aspects characteristic of the GBM vascular compartment because of an intricate crosstalk between the different angiogenic networks. Additionally, we explore the repertoire of emerging therapies against GBM that are currently under study, concluding with a question: faced with such a challenging scenario, could combined therapies, tailored to the patient's genetic signatures, represent an effective game changer?

Critical Review of Ketogenic Diet Throughout the Cancer Continuum for Neuroglioma: Insights from a Medical Nutrition Therapy (MNT) Perspective

PURPOSE OF REVIEW: A Ketogenic diet (KD; a diet comprised of 75% fat, 20% protein and 5% carbohydrates) has gained much popularity in recent years, especially regarding neurogliomas (or "gliomas"). This review critically assesses literature on the application of KD throughout the cancer continuum from a Medical Nutrition Therapy (MNT) perspective. RECENT FINDINGS: 2021 revised classification standards for Central Nervous System (CNS) tumors are available. Despite research on KD and CNS tumors increasing, the role and benefits of MNT to augment side effects of traditional treatment and KD throughout the cancer continuum remain unclear. Glioma cancer survivors may benefit from a KD. It is a challenging, yet feasible non-pharmacological adjuvant approach. More research is needed regarding KD for prevention and post-treatment of glioma. Standard guidelines regarding macronutrient composition of KD for glioma are warranted. The need and benefits of nutritional guidance provided by a Registered Dietitian Nutritionist (RD or RDNs) during adherence to KD are understated.

The role of sphingolipid rheostat in the adult-type diffuse glioma pathogenesis

Gliomas are highly aggressive primary brain tumors, with glioblastoma multiforme being the most severe and the most common one. Aberrations in sphingolipid metabolism are a hallmark of glioma cells. The sphingolipid rheostat represents the balance between the pro-apoptotic ceramide and pro-survival sphingosine-1-phosphate (S1P), and in gliomas it is shifted toward cell survival and proliferation, promoting gliomas' aggressiveness, cellular migration, metastasis, and invasiveness. The sphingolipid rheostat can be altered by targeting enzymes that directly or indirectly affect the ratio of ceramide to S1P, leading to increased ceramide or decreased S1P levels. Targeting the sphingolipid rheostat offers a potential therapeutic pathway for glioma treatment which can be considered through reducing S1P levels or modulating S1P receptors to reduce cell proliferation, as well as through increasing ceramide levels to induce apoptosis in glioma cells. Although the practical translation into clinical therapy is still missing, sphingolipid rheostat targeting in gliomas has been of great research interest in recent years with several interesting achievements in the glioma therapy approach, offering hope for patients suffering from these vicious malignancies.

Mucins as Precision Biomarkers in Glioma: Emerging Evidence for Their Potential in Biospecimen Analysis and Outcome Prediction

Despite attempts at improving survival by employing novel therapies, progression in glioma is nearly universal. Precision biomarkers are critical to advancing outcomes; however, biomarkers for glioma are currently unknown. Most data on which the field can draw for biomarker identification comprise tissue-based analysis requiring the biospecimen to be removed from the tumor. Non-invasive specimen-based precision biomarkers are needed. Mucins are captured in tissue and blood and are increasingly studied in cancer, with several studies exploring their role as biomarkers to detect disease and monitor disease progression. CA125, also known as MUC16, is implemented as a biomarker in the clinic for ovarian cancer. Similarly, several mucins are membrane-bound, facilitating downstream signaling associated with tumor resistance and hallmarks of cancer. Evidence supports mucin expression in glioma cells with relationships to tumor detection, progression, resistance, and patient outcomes. The differential expression of mucins across tissues and organs could also provide a means of attributing signals measured in serum or plasma. In this review, we compiled existing research on mucins as candidate precision biomarkers in glioma, focusing on promising mucins in relationship to glioma and leading to a framework for mucin analysis in biospecimens as well as avenues for validation as data evolve.

MicroRNA-146 family: Molecular insights into their role in regulation of signaling pathways in glioma progression

Glioma is a highly lethal brain cancer in humans. Despite advancements in treatment, the prognosis for patients remains unfavorable. Epigenetic factors, along with their interactions and non-coding RNAs (ncRNAs), are crucial in glioma cells' development and aggressive characteristics. MicroRNAs (miRNAs) are a class of small non-coding RNAs (ncRNAs) that modulate the expression of various genes by binding to target mRNA molecules. They play a critical role in regulating essential biological mechanisms such as cell proliferation and differentiation, cell cycle, and apoptosis. MiR-146a/miR-146b is a significant and prevalent miRNA whose expression alterations are linked to various pathological changes in cancer cells, as well as the modulation of several cellular signaling pathways, including NF-κB, TGF-β, PI3K/Akt, and Notch-1. Scientists may identify novel targets in clinical settings by studying the complicated link between Mir-146a/mir-146b, drug resistance, molecular pathways, and pharmacological intervention in gliomas. Additionally, its interactions with other ncRNAs, such as circular RNA and long non-coding RNA, contribute to the pathogenesis of glioma. As well as miR-146 holds potential as both a diagnostic and therapeutic biomarker for patients with this condition. In the current review, we investigate the significance of miRNAs in the context of glioma, with a particular focus on the critical role of Mir-146a/mir-146b in glioma tumors. Additionally, we examined the clinical relevance of this miRNA, highlighting its potential implications for diagnosis and treatment.

Integrative analysis of single-cell transcriptomic and multilayer signaling networks in glioma reveal tumor progression stage

Introduction

Tumor microenvironments (TMEs) encompass complex ecosystems of cancer cells, infiltrating immune cells, and diverse cell types. Intercellular and intracellular signals within the TME significantly influence cancer progression and therapeutic outcomes. Although computational tools are available to study TME interactions, explicitly modeling tumor progression across different cancer types remains a challenge.

Methods

This study introduces a comprehensive framework utilizing single-cell RNA sequencing (scRNA-seq) data within a multilayer network model, designed to investigate molecular changes across glioma progression stages. The heterogeneous, multilayered network model replicates the hierarchical structure of biological systems, from genetic building blocks to cellular functions and phenotypic manifestations.

Results

Applying this framework to glioma scRNA-seq data allowed complex network analysis of different cancer stages, revealing significant ligand‒receptor interactions and key ligand‒receptor-transcription factor (TF) axes, along with their associated biological pathways. Differential network analysis between grade III and grade IV glioma highlighted the most critical nodes and edges involved in interaction rewiring. Pathway enrichment analysis identified four essential genes-PDGFA (ligand), PDGFRA (receptor), CREB1 (TF), and PLAT (target gene)-involved in the Receptor Tyrosine Kinases (RTK) signaling pathway, which plays a pivotal role in glioma progression from grade III to grade IV.

Discussion

These genes emerged as significant features for machine learning in predicting glioma progression stages, achieving 87% accuracy and 93% AUC in a 3-year survival prediction through Kaplan-Meier analysis. This framework provides deeper insights into the cellular machinery of glioma, revealing key molecular relationships that may inform prognosis and therapeutic strategies.

Ferroptosis in glioma therapy: advancements in sensitizing strategies and the complex tumor-promoting roles

Ferroptosis, an iron-dependent form of non-apoptotic regulated cell death, is induced by the accumulation of lipid peroxides on cellular membranes. Over the past decade, ferroptosis has emerged as a crucial process implicated in various physiological and pathological systems. Positioned as an alternative modality of cell death, ferroptosis holds promise for eliminating cancer cells that have developed resistance to apoptosis induced by conventional therapeutics. This has led to a growing interest in leveraging ferroptosis for cancer therapy across diverse malignancies. Gliomas are tumors arising from glial or precursor cells, with glioblastoma (GBM) being the most common malignant primary brain tumor that is associated with a dismal prognosis. This review provides a summary of recent advancements in the exploration of ferroptosis-sensitizing methods, with a specific focus on their potential application in enhancing the treatment of gliomas. In addition to summarizing the therapeutic potential, this review also discusses the intricate interplay of ferroptosis and its potential tumor-promoting roles within gliomas. Recognizing these dual roles is essential, as they could potentially complicate the therapeutic benefits of ferroptosis. Exploring strategies aimed at circumventing these tumor-promoting roles could enhance the overall therapeutic efficacy of ferroptosis in the context of glioma treatment.

Correlation of LLT-1 and NLRC4 inflammasome and its effect on glioblastoma prognosis

PURPOSE

LLT-1 is a well-known ligand for the natural killer (NK) cell inhibitory receptor NKRP1A. Here, we examined NLRC4 inflammasome components and LLT-1 expression in glioblastoma (GBM) tissues to elucidate potential associations and interactions between these factors.

METHODS

GBM tissues were collected for RNA sequencing (RNA-seq) and Immunofluorescent experiments. Colocalization of LLT-1 and other proteins was assessed by immunofluorescence. Computational analyses utilized RNA-seq data from 296 to 52 patients from the Chinese Glioma Genome Atlas and CHA medical records, respectively. These data were subjected to survival, non-negative matrix factorization clustering, Gene Ontology enrichment, and protein-protein interaction analyses. Receptor-ligand interactions between tumor and immune cells were confirmed by single-cell RNA-seq analysis.

RESULTS

In GBM tissues, LLT-1 was predominantly colocalized with glial fibrillary acidic protein (GFAP)-expressing astrocytes, but not with microglial markers like Iba-1. Additionally, LLT-1 and activated NLRC4 inflammasomes were mainly co-expressed in intratumoral astrocytes, suggesting an association between LLT-1, NLRC4, and glioma malignancy. High LLT-1 expression correlates with poor prognosis, particularly in the mesenchymal subtype, and is associated with TNF and NOD-like receptor signaling pathway enrichment, indicating a potential role in tumor inflammation and progression. At the single-cell level, mesenchymal-like malignant cells showed high NF, NLR, and IL-1 signaling pathway enrichment compared to other malignant cell types.

CONCLUSION

We revealed an association between NLRC4 inflammasome activity and LLT-1 expression, suggesting a novel regulatory pathway involving TNF, inflammasomes, and IL-1, potentially offering new NK-cell-mediated anti-glioma approaches.

Full kinetic modeling analysis of [18F]fluorocholine Positron Emission Tomography (PET) at initial diagnosis of high-grade glioma

PURPOSE

The main objective was to characterize the tracer uptake kinetics of [18F]fluoromethylcholine ([18F]F-CHO) in high-grade gliomas (HGG) through a full PET kinetic modeling approach. Secondarily, we aimed to explore the relationship between the PET uptake measures and the HGG molecular features.

MATERIALS AND METHODS

Twenty-four patients with a suspected diagnosis of HGG were prospectively included. They underwent a dynamic brain [18F]F-CHO-PET/CT, from which a tumoral time-activity curve was extracted. The plasma input function was obtained through arterial blood sampling with metabolite correction. These data were fitted to 1- and 2-tissue-compartment models, the best of which was selected through the Akaike information criterion. We assessed the correlation between the kinetic parameters and the conventional static PET metrics (SUVmax, SUVmean and tumor-to-background ratio TBR). We explored the association between the [18F]F-CHO-PET quantitative parameters and relevant molecular biomarkers in HGG.

RESULTS

Tumoral time-activity curves in all patients showed a rapid rise of [18F]F-CHO uptake followed by a plateau-like shape. Best fits were obtained with near-irreversible 2-tissue-compartment models. The perfusion-transport constant K1 and the net influx rate Ki showed strong correlation with SUVmax (r = 0.808-0.861), SUVmean (r = 0.794-0.851) and TBR (r = 0.643-0.784), p < 0.002. HGG was confirmed in 21 patients, of which those with methylation of the O-6-methylguanine-DNA methyltransferase (MGMT) gene promoter showed higher mean Ki (p = 0.020), K1 (p = 0.025) and TBR (p = 0.001) than the unmethylated ones.

CONCLUSION

[18F]F-CHO uptake kinetics in HGG is best explained by a 2-tissue-compartment model. The conventional static [18F]F-CHO-PET measures have been validated against the perfusion-transport constant (K1) and the net influx rate (Ki) derived from kinetic modeling. A relationship between [18F]F-CHO uptake rate and MGMT methylation is suggested but needs further confirmation.

Nano-hydroxyapatite promotes cell apoptosis by co-activating endoplasmic reticulum stress and mitochondria damage to inhibit glioma growth

Despite a growing body of studies demonstrating the specific anti-tumor effect of nano-hydroxyapatite (n-HA), the underlying mechanism remained unclear. Endoplasmic reticulum (ER) and mitochondria are two key players in intracellular Ca2+ homeostasis and both require Ca2+ to participate. Moreover, the ER-mitochondria interplay coordinates the maintenance of cellular Ca2+ homeostasis to prevent any negative consequences from excess of Ca2+, hence there needs in-depth study of n-HA effect on them. In this study, we fabricated needle-like n-HA to investigate the anti-tumor effectiveness as well as the underlying mechanisms from cellular and molecular perspectives. Data from in vitro experiments indicated that the growth and invasion of glioma cells were obviously reduced with the aid of n-HA. It is interesting to note that the expression of ER stress biomarkers (GRP78, p-IRE1, p-PERK, PERK, and ATF6) were all upregulated after n-HA treatment, along with the activation of the pro-apoptotic transcription factor CHOP, showing that ER stress produced by n-HA triggered cell apoptosis. Moreover, the increased expression level of intracellular reactive oxygen species and the mitochondrial membrane depolarization, as well as the downstream cell apoptotic signaling activation, further demonstrated the pro-apoptotic roles of n-HA induced Ca2+ overload through inducing mitochondria damage. The in vivo data provided additional evidence that n-HA caused ER stress and mitochondria damage in cells and effectively restrain the growth of glioma tumors. Collectively, the work showed that n-HA co-activated intracellular ER stress and mitochondria damage are critical triggers for cancer cells apoptosis, offering fresh perspectives on ER-mitochondria targeted anti-tumor therapy.

Fractals in the Neurosciences: A Translational Geographical Approach

The chapter presents three new fractal indices (fractal fragmentation index, fractal tentacularity index, and fractal anisotropy index) and normalized Kolmogorov complexity with proven applicability in geographic research, developed by the authors, and the possibility of their future use in neuroscience. The research demonstrates the relevance of fractal analysis in different fields and the basic concepts and principles of fractal geometry being sufficient for the development of models relevant to the studied reality. Also, the research highlighted the need to continue interdisciplinary research based on known fractal indicators, as well as the development of new analysis methods with the translational potential between fields.