Search Results (622)

Glioblastoma (GBM) is a highly aggressive brain tumor marked by invasive growth and therapy resistance. Tumor cells adapt to hostile conditions, such as hypoxia and nutrient deprivation, by activating survival mechanisms including autophagy and metabolic reprogramming. Among GBM-associated changes, hypersialylation, particularly, the aberrant expression of polysialic acid (PSA), has been linked to increased plasticity, motility, and immune evasion. PSA, a long α2,8-linked sialic acid polymer typically attached to the NCAM, is abundant in the embryonic brain and re-expressed in cancers, correlating with poor prognosis. Here, we investigated how PSA expression was regulated in GBM cells under nutrient-limiting conditions. Serum starvation induced a marked increase in PSA-NCAM, driven by upregulation of the polysialyltransferase ST8SiaIV and an autophagy-dependent recycling of sialic acids from degraded glycoproteins. Inhibition of autophagy or sialidases impaired PSA induction, and PSA regulation appeared dependent on p53 function. Immunohistochemical analysis of GBM tissues revealed co-localization of PSA and LC3, particularly around necrotic regions. In conclusion, we identified a novel mechanism by which GBM cells sustain PSA-NCAM expression via autophagy-mediated sialic acid recycling under nutrient stress. This pathway may enhance cell migration, immune escape, and stem-like properties, offering a potential therapeutic target in GBM. Full article

Glioblastoma (GBM) is the most aggressive primary brain tumor, characterized by rapid progression, profound heterogeneity, and resistance to conventional therapies. This review provides an integrated overview of GBM’s pathophysiology, highlighting key mechanisms such as neuroinflammation, genetic alterations (e.g., EGFR, PDGFRA), the tumor microenvironment, microbiome interactions, and molecular dysregulations involving gangliosides and sphingolipids. Current diagnostic strategies, including imaging, histopathology, immunohistochemistry, and emerging liquid biopsy techniques, are explored for their role in improving early detection and monitoring. Treatment remains challenging, with standard therapies—surgery, radiotherapy, and temozolomide—offering limited survival benefits. Innovative therapies are increasingly being explored and implemented, including immune checkpoint inhibitors, CAR-T cell therapy, dendritic and peptide vaccines, and oncolytic virotherapy. Advances in nanotechnology and personalized medicine, such as individualized multimodal immunotherapy and NanoTherm therapy, are also discussed as strategies to overcome the blood–brain barrier and tumor heterogeneity. Additionally, stem cell-based approaches show promise in targeted drug delivery and immune modulation. Non-conventional strategies such as ketogenic diets and palliative care are also evaluated for their adjunctive potential. While novel therapies hold promise, GBM’s complexity demands continued interdisciplinary research to improve prognosis, treatment response, and patient quality of life. This review underscores the urgent need for personalized, multimodal strategies in combating this devastating malignancy. Full article

Glioblastoma (GBM) is a highly aggressive and heterogeneous brain tumor. Glioma stem-like cells (GSCs) play a central role in tumor progression, therapeutic resistance, and recurrence. Although immune cells are known to shape the GBM microenvironment, the impact of antigen-presenting-cell (APC) signature genes on tumor-intrinsic phenotypes remains underexplored. We analyzed both bulk- and single-cell RNA sequencing datasets of GBM to investigate the association between APC gene expression and tumor-cell states, including stemness and metabolic reprogramming. Signature scores were computed using curated gene sets related to APC activity, KEGG metabolic pathways, and cancer hallmark pathways. Protein–protein interaction (PPI) networks were constructed to examine the links between immune regulators and metabolic programs. The high expression of APC-related genes, such as HLA-DRA, CD74, CD80, CD86, and CIITA, was associated with lower stemness signatures and enhanced inflammatory signaling. These APC-high states (mean difference = –0.43, adjusted p < 0.001) also showed a shift in metabolic activity, with decreased oxidative phosphorylation and increased lipid and steroid metabolism. This pattern suggests coordinated changes in immune activity and metabolic status. Furthermore, TNF-α and other inflammatory markers were more highly expressed in the less stem-like tumor cells, indicating a possible role of inflammation in promoting differentiation. Our findings revealed that elevated APC gene signatures are associated with more differentiated and metabolically specialized GBM cell states. These transcriptional features may also reflect greater immunogenicity and inflammation sensitivity. The APC metabolic signature may serve as a useful biomarker to identify GBM subpopulations with reduced stemness and increased immune engagement, offering potential therapeutic implications. Full article

Cellular senescence is a state of the durable cell cycle arrest of dysfunctional cells, which has been associated with the promotion of tumor cell reprogramming into a stem cell state. We previously reported that the mixed lineage kinase (MLK) inhibitor CEP-1347 promotes the differentiation of glioma stem cells (GSCs)—key contributors to glioblastoma recurrence and therapy resistance—into non-stem tumor cells. However, we also noted that CEP-1347–treated GSCs exhibited a morphological change suggestive of senescence. Therefore, we herein investigated whether CEP-1347 induces senescence in GSCs and, consequently, if senescent GSCs may be eliminated using senolytics. Cell death induced by CEP-1347 in combination with senolytic agents or with the knockdown of anti-apoptotic BCL2 family genes, as well as the effects of CEP-1347 on the expression of senescence markers and anti-apoptotic Bcl-2 family proteins, were examined. The results obtained showed that CEP-1347 induced senescence in GSCs accompanied by the increased expression of Bcl-xL. Among the panel of senolytic agents tested, navitoclax, a BH3 mimetic, efficiently induced cell death in GSCs when combined with CEP-1347 at concentrations clinically achievable in the brain. The knockdown of Bcl-xL resulted in more pronounced GSC death in combination with CEP-1347 than that of Bcl-2. These results suggest that combining CEP-1347 with the targeting of Bcl-xL, the expression of which increases with CEP-1347-induced senescence, is a rational approach to ensure the elimination of GSCs, thereby improving the outcomes of glioblastoma treatment. Full article

Sirtuins (SIRTs), a family of NAD+-dependent enzymes, play crucial roles in epigenetic regulation, metabolism, DNA repair, and stress response, making them relevant to glioma biology. This review systematically summarizes the molecular mechanisms and context-specific functions of SIRT1–SIRT7 in central nervous system tumors, with particular focus on gliomas. SIRT1, SIRT3, SIRT5, and SIRT7 are often overexpressed and promote glioma cell proliferation, stemness, therapy resistance, and metabolic adaptation. Conversely, SIRT2, SIRT4, and SIRT6 generally exhibit tumor-suppressive functions by inducing apoptosis, inhibiting invasion, and counteracting oncogenic signaling. Preclinical studies have identified several sirtuin modulators—both inhibitors and activators—that alter tumor growth, sensitize cells to temozolomide, and regulate pathways such as JAK2/STAT3, NF-κB, and mitochondrial metabolism. Emerging evidence positions sirtuins as promising targets for glioma therapy. Future studies should evaluate sirtuin modulators in clinical trials and explore their potential for patient stratification and combined treatment strategies. Full article

Glioblastoma (GBM) is the most common malignant brain tumor, with a poor prognosis and low survival. Its treatment includes complete surgical resection followed by radiotherapy combined with temozolomide (TMZ). GBM contains glial stem cells (GSCs), which contribute to tumor progression, invasiveness, and drug resistance. The histone deacetylase (HDAC) inhibitor valproic acid (VA) has been shown to be a potent antitumor and cytostatic agent. In this study, we tested the effects of VA on glioma cell proliferation, migration, and apoptosis using T98G monolayer and spheroid cells. T98G and U-87MG glioblastoma cell viability was determined by MTT. Cell cycle and ROS levels were analyzed by flow cytometry, and gene and protein levels were detected, respectively, by RT-PCR and immunoblotting. VA reduces cell viability in 2D and 3D T98G and U-87MG cells and blocks the cell cycle at the G0/G1 with decreased levels of cyclin D1. VA addresses apoptosis and ROS production. In addition, VA significantly decreases the mRNA levels of the mesenchymal markers, and it counteracts cell migration, also decreasing MMP2. The results confirm the inhibitory effect of VA on the growth of the T98G and U-87MG cell lines and its ability to counteract migration in both 2D and 3D cellular models. Full article

Background: Protein arginine methyltransferase 3 (PRMT3), a type I family PRMT, regulates the activity of downstream substrates by catalyzing the asymmetric dimethylation of arginine residues. While PRMT3 activity has been reported to be deregulated in many cancers, including glioblastoma (GBM), the underlying signalling mechanisms that contribute to disease progression are largely unknown. Methods: We tested the efficacy of a PRMT3 chemical probe, SGC707, in a cohort of GBM patient-derived primary and recurrent brain tumour stem cell (BTSC) lines. RNA-sequencing, CRISPR-cas9 knockout, and inducible overexpression methods were used to investigate the molecular mechanisms regulated by the aberrant activity of PRMT3 in different BTSC lines. Results: We show that expression of the tumour suppressor protein 4.1B, a negative regulator of PRMT3, predicts the response of GBM BTSCs to the PRMT3 chemical probe, SGC707. Furthermore, PRMT3 modulates the stability and subcellular localization of the downstream effector, UHRF1, a member of the DNA methylation complex. These findings suggest that UHRF1 and DNMT1 may suppress the expression of 4.1B through the increased promoter methylation of EPB4.1L3. Intriguingly, the inducible overexpression of EPB4.1L3 in the BT248^EPB4.1L3low BTSC line mimicked the effects of the pharmacologic and genetic inhibition of PRMT3. In contrast, knockout of EPB4.1L3 in BT143^EPB4.1L3high cells reduced the interactions between PRMT3 and 4.1B proteins, resulting in increased sensitivity of knockout cells to SGC707 treatment. Conclusions: These findings show that 4.1B, PRMT3, and UHRF1/DNMT1 function together to promote BTSC growth. Thus, targeting PRMT3 or UHRF1/DNMT1, especially in tumours with low endogenous 4.1B protein, may have high therapeutic relevance. Full article

Isoforms of prostate transmembrane protein, androgen induced 1 (PMEPA1), are regulated either by TGF-beta or AR activation and provide negative loop-regulation of these signaling pathways. High levels of PMEPA1 protein have been observed in various tumor types, including prostate, bladder, colorectal cancers, and glioblastoma. Direct oncogenic role of PMEPA1 in hepatocellular carcinoma has been recently shown on an animal model. New studies also indicate an upregulation of PMEPA1 in tumor-associated immune and stromal cells; however, its specific role in tumor stromal cells remains largely unexplored. In our previous research, we developed a cancer-stroma sphere (CSS) model that integrates tumor cells with mesenchymal stem cells (MSCs). Evaluations of chemotherapy and CAR-T therapies on CSSs have demonstrated that this model closely mimics in vivo data regarding cytotoxicity and adverse effects of therapy. In the present study, we reveal that PMEPA1 is significantly overexpressed in MSCs within the CSS. Moreover, this overexpression has been induced under short-term co-culture conditions. Among the five isoforms of PMEPA1, PMEPA1a and PMEPA1b isoforms have been detected in MSCs. These findings underscore the potential role of PMEPA1 in the tumor microenvironment modulation by MSCs. Full article

Bardoxolone methyl, also known as CDDO-Me or RTA 402, is a synthetic oleanane triterpenoid that has garnered significant attention as a potent pharmacological activator of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Nrf2 is a master regulator of cellular redox homeostasis, controlling the expression of genes involved in antioxidant defense, detoxification, and mitochondrial function. By inducing Nrf2 and promoting the transcription of downstream antioxidant response element (ARE)-driven genes, bardoxolone methyl enhances cellular resilience to oxidative stress and inflammation. This mechanism is central not only to its cytoprotective effects but also to its emerging role in oncology. A number of studies investigated the effects of bardoxolone methyl in several malignancies including breast cancer, lung cancer, pancreatic ductal adenocarcinoma, prostate cancer, colorectal cancer, oral and esophageal squamous cell carcinoma, ovarian cancer and glioblastoma. Studies in the literature indicate that bardoxolone methyl exhibits anticancer activity through several mechanisms, including the suppression of cell proliferation, induction of cell cycle arrest and apoptosis, inhibition of epithelial–mesenchymal transition (EMT), and impairment of cancer cell stemness. Additionally, bardoxolone methyl modulates mitochondrial function, reduces glycolytic and oxidative phosphorylation capacities, and induces reactive oxygen species (ROS)-mediated stress responses. In this review, we summarize the available literature regarding the studies which investigated the effects of bardoxolone methyl as anticancer agent. Full article

Enhancement of glycolysis has been reported in tumor cells, and it is believed that this enhancement is important for maintaining the stemness of tumor cells and contributes to malignant phenotypes. Here, we investigated the effects of Oxamate, which inhibits glycolysis by blocking the conversion of pyruvate to lactate, on radiosensitivity and its molecular mechanisms in T98G glioblastoma cells. Oxamate significantly enhanced radiosensitivity by delaying DNA repair, as indicated by the persistence of γ-H2AX foci up to four days post-irradiation. Mechanistically, Oxamate suppressed the expression and phosphorylation of key DNA repair factors. Furthermore, Oxamate induced apoptosis and promoted cellular senescence, as evidenced by the accumulation of SA-β-gal and the upregulation of pS15-p53 and p21. In addition, Oxamate downregulated EGFR expression, reduced the levels of stem cell markers, and modulated epithelial–mesenchymal transition (EMT) markers, suggesting a potential suppression of EMT-related pathways. Together, these results demonstrate that Oxamate enhances radiosensitivity in glioblastoma cells through multiple mechanisms, including the inhibition of DNA repair, induction of apoptosis and senescence, and suppression of cancer stem cell properties and EMT. Our findings provide new insights into the potential use of Oxamate as a radiosensitizer and warrant further investigation of its clinical application in glioblastoma therapy. Full article

The WHO estimates that nearly 10–15% of cancers have a known viral etiology, although this number is likely an underestimate. In glioblastoma (GBM), the most common primary brain malignancy, viral associations have been proposed and investigated without a definitive etiology. Viral–host interactions are known to alter cellular growth and stem cell programming, as well as modulate innate immune signaling. However, in GBM, the multifaceted role of endogenous or exogenous viral expression remains unclear. Here, we provide a review of common viral associations in GBM and discuss how these viruses modulate intrinsic cellular processes to enhance anti-viral immune response or suppress anti-tumor immunity. Full article

Gliomas are the most common central nervous system tumors and account for 30% of all primary brain tumors, 80% of all malignant ones, and the vast majority of deaths that are caused by brain tumors. Among them, glioblastoma multiforme has the most aggressive and invasive course. Due to its heterogeneity, it is difficult to treat, and one of the reasons for this are glioma stem cells (GSCs). Therapies such as radiotherapy and chemotherapy are used to treat gliomas but do not bring the expected results. Therefore, treatments targeting glioma stem cells are emerging. A promising strategy is to target GSCs with natural compounds. This review aims to describe the problem of glioma stem cells, the treatment of gliomas, and therapies based on natural compounds, which are promising for the future. Full article

Glioblastoma (GBM) is the most aggressive and challenging brain cancer, in terms of diagnosis and therapy. The highly infiltrative glioblastoma stem cells (GSCs) are difficult to visualize and surgically remove with the current diagnostic tools, which often lead to misdiagnosis and false-positive results. In this study, we focused on a groundbreaking tool for specifically visualizing and removing GSCs. We exploited the specific binding of A40s aptamer to EphA2 for the selective delivery of Near-Infrared Dyes (NIR-Dyes), like IR700DX and ICG, both in vitro and in vivo. The A40s aptamer, engineered through the NIR-Dye conjugation, did not affect aptamer binding ability; indeed, A40s-NIR-Dye conjugates bound GLI261 stem-like cells and patient-derived GSCs in vitro; moreover, they induced cell death upon photodynamic therapy treatment (PDT). Additionally, when systemically administrated, the A40s-NIR-Dye conjugates allowed GSC visualization and accumulated in tumor mass. This allows GSCs detection and treatment. Our findings demonstrate the potential use of A40s aptamer as a targeted therapeutic approach and imaging tool in vivo for GSCs, paving the way for improved, more effective, and less invasive GBM management. Full article

Brain tumors, in particular gliomas and glioblastoma multiforme (GBM), are thought to originate from different cells facing specific founding insults, a feature that partly justifies the complexity and heterogeneity of these severe forms of cancer. However, gliomas and GBM are usually reproduced in animal models by inducing molecular alterations in mature glial cells, which, though being part of the puzzle, do not represent the whole picture. To fill this conceptual gap, we previously developed a neurogenic model of brain cancer in Drosophila, demonstrating that the loss of cell polarity in neural stem cells (called neuroblasts in the fruit fly) is sufficient to promote the formation of malignant masses that continue to grow in the adult, displaying several phenotypic traits typical of human GBM. Here, we expand on previous work by restricting polarity disruption to Drosophila type II neuroblasts, whose self-renewal is comparable to that of mammalian neural progenitors, with the aim to capture the molecular signature of the resulting cancers in a specific and reproducible context. A comparison of the most deregulated transcripts with those found in human primary GBMs confirmed that our model can be proficiently used to delve into the roots of human brain tumorigenesis. Full article

Background: Glioblastoma (GBM) is the most malignant brain tumor, with a cellular hierarchy dominated by glioma stem cells (GSCs). Understanding global communications among GSCs and other cells helps us identify potential new therapeutic targets. In this study, multi-transcriptomic analysis was utilized to explore the communication pattern of GSCs in GBM. Methods: CellChat was used to quantitatively infer and analyze intercellular communication networks from GBM single-cell RNA-sequencing (scRNA-seq) data. Gene set enrichment analysis (GSEA) was conducted to identify specific biological pathways (epithelial–mesenchymal transition, EMT) involved in the communication pattern of GSCs. Spatial transcriptomic database was used to support the relationship between EMT and GSC proliferation. Single-sample GSEA (ssGSEA) was employed to assess which GSC state exhibited the strongest association with the EMT signature. Results: The cell communication pattern of GSCs is mostly related to EMT. Multiple EMT-related genes are highly expressed in GBM, particularly in GSCs, which are associated with poor prognosis. In addition, EMT-related genes are most enriched in mesenchymal-like (MES-like) GSCs. Tumor patients with MES-like GSC-enriched signatures demonstrate the most unfavorable prognosis compared to those harboring proneural-like (PN-like) or classical-like (CL-like) GSCs. Conclusions: This study suggests that GSCs facilitate GBM progression through intercellular communication in the pattern of EMT. EMT-associated genes may drive the differentiation of GSCs toward a MES-like phenotype, thereby leading to poorer clinical outcomes. Consequently, targeting EMT-related pathways could represent a novel therapeutic strategy for GBM treatment. Full article