Integrated genomic analysis identifies clinically relevant subtypes of glioblastoma characterized by abnormalities in PDGFRA, IDH1, EGFR, and NF1

Unveiling the antitumor mechanism of 7α-acetoxy-6β-hydroxyroyleanone from Plectranthus hadiensis in glioblastoma

ETHNOPHARMACOLOGICAL RELEVANCE

Glioblastoma (GB) is the most aggressive and prevalent glioma within the central nervous system. Despite considerable efforts, GB continues to exhibit a dismal 5-year survival rate (∼6%). This is largely attributed to unfavorable prognosis and lack of viable treatment options. Therefore, novel therapies centered around plant-derived compounds emerge as a compelling avenue to enhance patient survival and well-being. The South African species, Plectranthus hadiensis Schweinf. (P. hadiensis), a member of the Lamiaceae family, has a history of use in traditional medicine for treating a range of diseases, including respiratory, digestive, and liver disorders. This species exhibits diverse biological activities, such as anti-inflammatory and antitumoral properties, likely attributed to its rich composition of naturally occurring diterpenes, like the abietane diterpene, 7α-acetoxy-6β-hydroxyroyleanone (Roy). Roy has demonstrated promising antitumor effects in various cancer cell lines, making it a compelling candidate for further investigation into its mechanisms against GB.

AIM OF THE STUDY

This study aims to investigate the antitumor activity and potential mechanism of Roy, a natural lead compound, in GB cells.

MATERIAL AND METHODS

Roy was isolated from the acetonic extract of P. hadiensis and its antitumor mechanism was assessed in a panel of human GB cell lines (U87, A172, H4, U373, and U118) to mimic tumor heterogeneity. Briefly, the impact of Roy treatment on the metabolic activity of cells was evaluated by Alamar Blue® assay, while cell death, cell cycle regulation, mitochondrial membrane potential, and activated caspase-3 activity were evaluated by flow cytometry. Measurement of mRNA levels of target genes was performed by qPCR, while protein expression was assessed by Western blotting. Cell uptake and impact on mitochondrial morphology were evaluated by confocal microscopy.

RESULTS

Roy induced G2/M cell cycle arrest, mitochondrial fragmentation, and apoptosis by inhibiting the expression of anti-apoptotic proteins and increasing the levels of activated caspase-3. The concentrations of Roy needed to achieve significant inhibitory outcomes were notably lower (6-9 fold) than those of temozolomide (TMZ), the standard first-line treatment, for achieving comparable effects. In addition, at low concentrations (16 μM), Roy affected the metabolic activity of tumor cells while having no significant impact on non-tumoral cells (microglia and astrocytes).

CONCLUSION

Overall, Roy demonstrated a robust antitumor activity against GB cells offering a promising avenue for the development of novel chemotherapeutic approaches.

Hypoxia-driven heterogeneous expression of α5 integrin in glioblastoma stem cells is linked to HIF-2α

Despite numerous molecular targeted therapies tested in glioblastoma (GBM), no significant progress in patient survival has been achieved in the last 20 years in the overall population of GBM patients except with TTfield setup associated with the standard of care chemoradiotherapy. Therapy resistance is associated with target expression heterogeneity and plasticity between tumors and in tumor niches. We focused on α5 integrin implicated in aggressive GBM in preclinical and clinical samples. To address the characteristics of α5 integrin heterogeneity we started with patient data indicating that elevated levels of its mRNA are related to hypoxia pathways. We turned on glioma stem cells which are considered at the apex of tumor formation and recurrence but also as they localize in hypoxic niches. We demonstrated that α5 integrin expression is stem cell line dependent and is modulated positively by hypoxia in vitro. Importantly, heterogeneity of expression is conserved in in vivo stem cell-derived mice xenografts. In hypoxic niches, HIF-2α is preferentially implicated in α5 integrin expression which confers migratory capacity to GBM stem cells. Hence combining HIF-2α and α5 integrin inhibitors resulted in proliferation and migration impairment of α5 integrin expressing cells. Stabilization of HIF-2α is however not sufficient to control integrin α5 expression. Our results show that AHR (aryl hydrocarbon receptor) expression is inversely related to HIF-2α and α5 integrin expressions suggesting a functional competition between the two transcription factors. Collectively, data confirm the high heterogeneity of a GBM therapeutic target, its induction in hypoxic niches by HIF-2α and suggest a new way to attack molecularly defined GBM stem cells.

DNA methylation heterogeneity attributable to a complex tumor immune microenvironment prompts prognostic risk in glioma

Gliomas are malignant tumours of the human nervous system with different World Health Organization (WHO) classifications, glioblastoma (GBM) with higher grade and are more malignant than lower-grade glioma (LGG). To dissect how the DNA methylation heterogeneity in gliomas is influenced by the complex cellular composition of the tumour immune microenvironment, we first compared the DNA methylation profiles of purified human immune cells and bulk glioma tissue, stratifying three tumour immune microenvironmental subtypes for GBM and LGG samples from The Cancer Genome Atlas (TCGA). We found that more intermediate methylation sites were enriched in glioma tumour tissues, and used the Proportion of sites with Intermediate Methylation (PIM) to compare intertumoral DNA methylation heterogeneity. A larger PIM score reflected stronger DNA methylation heterogeneity. Enhanced DNA methylation heterogeneity was associated with stronger immune cell infiltration, better survival rates, and slower tumour progression in glioma patients. We then created a Cell-type-associated DNA Methylation Heterogeneity Contribution (CMHC) score to explore the impact of different immune cell types on heterogeneous CpG site (CpGct) in glioma tissues. We identified eight prognosis-related CpGct to construct a risk score: the Cell-type-associated DNA Methylation Heterogeneity Risk (CMHR) score. CMHR was positively correlated with cytotoxic T-lymphocyte infiltration (CTL), and showed better predictive performance for IDH status (AUC = 0.96) and glioma histological phenotype (AUC = 0.81). Furthermore, DNA methylation alterations of eight CpGct might be related to drug treatments of gliomas. In conclusion, we indicated that DNA methylation heterogeneity is associated with a complex tumour immune microenvironment, glioma phenotype, and patient's prognosis.

Are we better together? Addressing a combined treatment of pitavastatin and temozolomide for brain cancer

Pitavastatin is commonly prescribed to treat hypercholesterolemia through the regulation of cholesterol biosynthesis. Interestingly, it has also demonstrated a great potential for treating brain tumors, although the detailed cytotoxic mechanism, particularly in glioblastoma, remains incompletely understood. This work explores the activity of pitavastatin in 2D and 3D glioblastoma models, in an attempt to provide a more representative and robust overview of its anticancer potential in glioblastoma. The results show that not only is pitavastatin 10-1000 times-fold more effective in reducing tumoral metabolic activity than temozolomide, but also demonstrate a synergistic activity with this alkylating drug. In addition, low micromolar concentrations of this statin strongly impair the growth and the invasion ability of multicellular tumor spheroids. The obtained qRT-PCR and proteomics data highlight the modulation of cell death via apoptosis (BAX/BCL2, CASP9) and autophagy (BECN1, BNIP3, BNIP3L and LC3B), as well as an epithelial to mesenchymal transition blockage (HTRA1, SERPINE1, WNT5A, ALDH3B1 and EPHA2) and remodeling of the extracellular matrix (VCAN, SERPINE1 and TGFBI). Overall, these results lay the foundation for further investigations on the potential combinatory clinical treatment with temozolomide.

FABP4 facilitates epithelial-mesenchymal transition via elevating CD36 expression in glioma cells

Glioblastoma multiforme (GBM) is the most aggressive brain tumor with poor prognosis. A better understanding of mechanisms concerned in glioma invasion might be critical for treatment optimization. Given that epithelial-mesenchymal transition in tumor cells is closely associated with glioma progression and recurrence, identifying pivotal mediators in GBM EMT process is urgently needed. As a member of Fatty acid binding protein (FABP) family, FABP4 serves as chaperones for free fatty acids and participates in cellular process including fatty acid uptake, transport, and metabolism. In this study, our data revealed that FABP4 expression was elevated in human GBM samples and correlated with a mesenchymal glioma subtype. Gain of function and loss of function experiments indicated that FABP4 potently rendered glioma cells increased filopodia formation and cell invasiveness. Differential expression genes analysis and GSEA in TCGA dataset revealed an EMT-related molecular signature in FABP4-mediated signaling pathways. Cell interaction analysis suggested CD36 as a potential target regulated by FABP4. Furthermore, in vitro mechanistic experiments demonstrated that FABP4-induced CD36 expression promoted EMT via non-canonical TGFβ pathways. An intracranial glioma model was constructed to assess the effect of FABP4 on tumor progression in vivo. Together, our findings demonstrated a critical role for FABP4 in the regulation invasion and EMT in GBM, and suggest that pharmacological inhibition of FABP4 may represent a promising therapeutic strategy for treatment of GBM.

Fibrillar extracellular matrix produced by pericyte-like cells facilitates glioma cell dissemination

Gliomagenesis induces profound changes in the composition of the extracellular matrix (ECM) of the brain. In this study, we identified a cellular population responsible for the increased deposition of collagen I and fibronectin in glioblastoma. Elevated levels of the fibrillar proteins collagen I and fibronectin were associated with the expression of fibroblast activation protein (FAP), which is predominantly found in pericyte-like cells in glioblastoma. FAP+ pericyte-like cells were present in regions rich in collagen I and fibronectin in biopsy material and produced substantially more collagen I and fibronectin in vitro compared to other cell types found in the GBM microenvironment. Using mass spectrometry, we demonstrated that 3D matrices produced by FAP+ pericyte-like cells are rich in collagen I and fibronectin and contain several basement membrane proteins. This expression pattern differed markedly from glioma cells. Finally, we have shown that ECM produced by FAP+ pericyte-like cells enhances the migration of glioma cells including glioma stem-like cells, promotes their adhesion, and activates focal adhesion kinase (FAK) signaling. Taken together, our findings establish FAP+ pericyte-like cells as crucial producers of a complex ECM rich in collagen I and fibronectin, facilitating the dissemination of glioma cells through FAK activation.

PDGF-BB overexpression in p53 null oligodendrocyte progenitors increases H3K27me3 and induces transcriptional changes which favor proliferation

Proneural gliomas are brain tumors characterized by enrichment of oligodendrocyte progenitor cell (OPC) transcripts and genetic alterations. In this study we sought to identify transcriptional and epigenetic differences between OPCs with Trp53 deletion and PDGF-BB overexpression (BB-p53n) and those carrying only p53 deletion (p53n). In culture, the BB-p53n OPCs display growth characteristics more similar to glioma cells than p53n OPCs. When injected in mouse brains, BB-p53n OPC form tumors, while the p53n OPCs do not. Unbiased histone proteomics and transcriptomic analysis on these OPC populations identified higher levels of the histone H3K27me3 mark and lower levels of the histone H4K20me3. The transcriptome of the BB-p53n OPCs was characterized by higher levels of transcripts related to proliferation and cell adhesion compared to p53n OPCs. Pharmacological inhibition of the enzyme responsible for histone H3K27 trimethylation (EZH2i) in BB-p53n OPCs, reduced cell cycle transcripts and increased the expression of differentiation markers, but was not sufficient to restore their growth characteristics. This suggests that PDGF-BB overexpression in p53n OPCs favors the early stages of transformation, by promoting proliferation and halting differentiation in a H3K27me3-dependent pathway, and favoring growth characteristics in a H3K27me3 independent manner.

MR Imaging-Guided Focused Ultrasound-Clinical Applications in Managing Malignant Gliomas

Malignant gliomas (MGs) are the most common primary brain tumors in adults. Despite recent advances in understanding the biology and potential therapeutic vulnerabilities of MGs, treatment options remain limited as the delivery of drugs is often impeded by the blood-brain barrier (BBB), and safe, complete surgical resection may not always be possible, especially for deep-seated tumors. In this review, the authors highlight emerging applications for MR imaging-guided focused ultrasound (MRgFUS) as a noninvasive treatment modality for MGs. Specifically, the authors discuss MRgFUS's potential role in direct tumor cell killing, opening the BBB, and modulating antitumor immunity.

The role of progranulin in macrophages of a glioblastoma model

PURPOSE

Glioblastoma (GBM), characterized by astrocytic tumorigenesis, remains one of the most prognostically challenging tumor types. Targeting entire GBM microenvironment using novel therapeutic factors is currently desired investigation approach. In this study, we focused on progranulin (PGRN), a regulator of diverse cellular functions. Recent studies implicated PGRN in the poor prognostics of GBM patients. However, the specific role of PGRN in the GBM microenvironment remains elusive.

METHODS

We utilized public databases of GBM patient and previous single-cell RNA sequence to examine association between PGRN expression and patient survival/grade, and expression levels of PGRN in each cell constituting the tumor microenvironment. To clarify the role of PGRN in Tumor-associated macrophage (TAM), we examined cell proliferation and expression of some proteins in murine GBM cells when cell supernatants derived from TAM of PGRN knockout (Grn-/-) or wild type mice were treated with murine GBM cells.

RESULTS

Our results reveal significant PGRN expression in macrophages within the GBM environment, suggesting an association between increased PGRN expression in macrophages and tumor malignancy. TAM induction led to PGRN expression enhancement. Treatment with Grn-/- mouse -derived bone marrow-derived macrophage (BMDM) supernatant resulted in diminished GBM cell proliferation and cell cycle- and mesenchymal GBM subtype-associated reduced protein expression. Furthermore, the Grn-/- mouse-derived BMDM supernatant treatment reduced the phosphorylated STAT3 expression in GBM cells, while the expression of IL-6 and IL-10, known STAT3 pathway activators, diminished in Grn-/- mouse-derived BMDMs.

CONCLUSION

Our results suggest that macrophage-derived PGRN is pivotal for fostering malignant transformations within the tumor microenvironment.

NF1 expression profiling in IDH-wildtype glioblastoma: genomic associations and survival outcomes

BACKGROUND

NF1 inactivation is associated with sensitivity to MEK inhibitor targeted therapy in low-grade and some high-grade gliomas. NF1 loss may also be a harbinger of exploitable vulnerabilities in IDH-wildtype glioblastoma (GBM). Accurate and consistent detection of NF1 loss, however, is fraught given the large gene size, challenges with complete coverage and variant calling upon sequencing, and mechanisms of mRNA and protein regulation that result in early degradation in the absence of genomic alterations. Here, we seek to perform a composite analysis for NF1 loss accounting for genomic alterations and protein expression via immunohistochemistry. We also characterize the landscape of NF1 alterations in GBM.

METHODS

We assembled a single-institution, retrospective cohort of 542 IDH-wildtype GBM with somatic next generation sequencing to investigate the frequency and nature of detected NF1 alterations. We selected 69 GBMs from which to build a tissue microarray (TMA) of 44 NF1-wildtype and 25 NF1-mutant cases. We performed NF1 immunohistochemistry using two different NF1 antibodies (NFC, Sigma-Aldrich; and iNF-07E, iNFixion Bioscience) and correlated results with clinical, genomic, and other immunohistochemical features.

RESULTS

In our retrospective cohort, we identified 88 IDH-wildtype GBM with NF1 alterations (16%). NF1 alterations were mutually exclusive with EGFR and MDM2 alterations (p-adj < 0.001, 0.05, respectively), but co-occurred with PIK3R1 alterations (Log2(OR) = - 1.6, p-adj = 0.03). Of the 63 scorable sporadic GBMs in the TMA, 14 harbored NF1 inactivating alterations and of those, 12 (86%) demonstrated minimal NF1 immunoreactivity by NFC antibody, compared to 8 (57%) by iNF-07E antibody. Among the 42 scorable NF1-wildtype GBM in the TMA, NF1 immunostaining was minimal in 18 (43%) by NFC antibody compared to 4 (10%) by iNF-07E antibody, potentially reflecting false positives or differential protein regulation. Minimal immunoreactivity by NFC antibody was associated with decreased median overall survival (8.5 vs. 16.4 months, p = 0.011). Cox proportional hazards model correcting for prognostic variables in this subset revealed HR 3.23 (95% CI 1.29-8.06, p = 0.01) associated with decreased NF1 expression by IHC.

CONCLUSION

NF1 immunostaining may serve as a sensitive surrogate marker of NF1 genomic inactivation and a valuable extension to next-generation sequencing for defining NF1 status. Minimal NF1 immunoreactivity is a poor prognostic marker, even in IDH-wildtype glioblastoma without apparent NF1 genomic alterations, but the underlying molecular mechanism requires further investigation.

A method for in silico exploration of potential glioblastoma multiforme attractors using single-cell RNA sequencing

We presented a method to find potential cancer attractors using single-cell RNA sequencing (scRNA-seq) data. We tested our method in a Glioblastoma Multiforme (GBM) dataset, an aggressive brain tumor presenting high heterogeneity. Using the cancer attractor concept, we argued that the GBM's underlying dynamics could partially explain the observed heterogeneity, with the dataset covering a representative region around the attractor. Exploratory data analysis revealed promising GBM's cellular clusters within a 3-dimensional marker space. We approximated the clusters' centroid as stable states and each cluster covariance matrix as defining confidence regions. To investigate the presence of attractors inside the confidence regions, we constructed a GBM gene regulatory network, defined a model for the dynamics, and prepared a framework for parameter estimation. An exploration of hyperparameter space allowed us to sample time series intending to simulate myriad variations of the tumor microenvironment. We obtained different densities of stable states across gene expression space and parameters displaying multistability across different clusters. Although we used our methodological approach in studying GBM, we would like to highlight its generality to other types of cancer. Therefore, this report contributes to an advance in the simulation of cancer dynamics and opens avenues to investigate potential therapeutic targets.

Practical immunomodulatory landscape of glioblastoma multiforme (GBM) therapy

Glioblastoma multiforme (GBM) is the most common harmful high-grade brain tumor with high mortality and low survival rate. Importantly, besides routine diagnostic and therapeutic methods, modern and useful practical techniques are urgently needed for this serious malignancy. Correspondingly, the translational medicine focusing on genetic and epigenetic profiles of glioblastoma, as well as the immune framework and brain microenvironment, based on these challenging findings, indicates that key clinical interventions include immunotherapy, such as immunoassay, oncolytic viral therapy, and chimeric antigen receptor T (CAR T) cell therapy, which are of great importance in both diagnosis and therapy. Relatively, vaccine therapy reflects the untapped confidence to enhance GBM outcomes. Ongoing advances in immunotherapy, which utilizes different methods to regenerate or modify the resistant body for cancer therapy, have revealed serious results with many different problems and difficulties for patients. Safe checkpoint inhibitors, adoptive cellular treatment, cellular and peptide antibodies, and other innovations give researchers an endless cluster of instruments to plan profoundly in personalized medicine and the potential for combination techniques. In this way, antibodies that block immune checkpoints, particularly those that target the program death 1 (PD-1)/PD-1 (PD-L1) ligand pathway, have improved prognosis in a wide range of diseases. However, its use in combination with chemotherapy, radiation therapy, or monotherapy is ineffective in treating GBM. The purpose of this review is to provide an up-to-date overview of the translational elements concentrating on the immunotherapeutic field of GBM alongside describing the molecular mechanism involved in GBM and related signaling pathways, presenting both historical perspectives and future directions underlying basic and clinical practice.

Developmental-status-aware transcriptional decomposition establishes a cell state panorama of human cancers

BACKGROUND

Cancer cells evolve under unique functional adaptations that unlock transcriptional programs embedded in adult stem and progenitor-like cells for progression, metastasis, and therapeutic resistance. However, it remains challenging to quantify the stemness-aware cell state of a tumor based on its gene expression profile.

METHODS

We develop a developmental-status-aware transcriptional decomposition strategy using single-cell RNA-sequencing-derived tissue-specific fetal and adult cell signatures as anchors. We apply our method to various biological contexts, including developing human organs, adult human tissues, experimentally induced differentiation cultures, and bulk human tumors, to benchmark its performance and to reveal novel biology of entangled developmental signaling in oncogenic processes.

RESULTS

Our strategy successfully captures complex dynamics in developmental tissue bulks, reveals remarkable cellular heterogeneity in adult tissues, and resolves the ambiguity of cell identities in in vitro transformations. Applying it to large patient cohorts of bulk RNA-seq, we identify clinically relevant cell-of-origin patterns and observe that decomposed fetal cell signals significantly increase in tumors versus normal tissues and metastases versus primary tumors. Across cancer types, the inferred fetal-state strength outperforms published stemness indices in predicting patient survival and confers substantially improved predictive power for therapeutic responses.

CONCLUSIONS

Our study not only provides a general approach to quantifying developmental-status-aware cell states of bulk samples but also constructs an information-rich, biologically interpretable, cell-state panorama of human cancers, enabling diverse translational applications.

Novel strategies to overcome chemoresistance in human glioblastoma

Temozolomide (TMZ) is currently the first-line chemotherapeutic agent for the treatment of glioblastoma multiforme (GBM). However, the inherent heterogeneity of GBM often results in suboptimal outcomes, particularly due to varying degrees of resistance to TMZ. Over the past several decades, O6-methylguanine-DNA methyltransferase (MGMT)-mediated DNA repair pathway has been extensively investigated as a target to overcome TMZ resistance. Nonetheless, the combination of small molecule covalent MGMT inhibitors with TMZ and other chemotherapeutic agents has frequently led to adverse clinical effects. Recently, additional mechanisms contributing to TMZ resistance have been identified, including epidermal growth factor receptor (EGFR) mutations, overactivation of intracellular signalling pathways, energy metabolism reprogramming or survival autophagy, and changes in tumor microenvironment (TME). These findings suggest that novel therapeutic strategies targeting these mechanisms hold promise for overcoming TMZ resistance in GBM patients. In this review, we summarize the latest advancements in understanding the mechanisms underlying intrinsic and acquired TMZ resistance. Additionally, we compile various small-molecule compounds with potential to mitigate chemoresistance in GBM. These mechanism-based compounds may enhance the sensitivity of GBM to TMZ and related chemotherapeutic agents, thereby improving overall survival rates in clinical practice.

Splicing dysregulation in glioblastoma alters the function of cell migration-related genes

Glioblastoma (GBM) has a poor prognosis with a high recurrence and low survival rate. Previous RNA-seq analyses have revealed that alternative splicing (AS) plays a role in GBM progression. Here, we present a novel AS analysis method (Semi-Q) and describe its use to identify GBM-specific AS events. We analyzed RNA-seq data from normal brain (NB), normal human astrocytes (NHAs) and GBM samples, and found that comparison between NHA and GBM was especially informative. Importantly, this analysis revealed that genes encoding cell migration-related proteins, including filamins (FLNs) and actinins (ACTNs), were among those most affected by differential AS. Functional assays revealed that dysregulated AS of FLNA, B and C transcripts produced protein isoforms that not only altered transcription of cell proliferation-related genes but also led to enhanced cell migration, resistance to cell death and/or mitochondrial respiratory function, while a dysregulated AS isoform of ACTN4 enhanced cell migration. Together, our results indicate that cell migration and actin cytoskeleton-related genes are differentially regulated by AS in GBM, supporting a role for AS in facilitating tumor growth and invasiveness.

Metabolism: an important player in glioma survival and development

Gliomas are malignant tumors originating from both neuroglial cells and neural stem cells. The involvement of neural stem cells contributes to the tumor's heterogeneity, affecting its metabolic features, development, and response to therapy. This review provides a brief introduction to the importance of metabolism in gliomas before systematically categorizing them into specific groups based on their histological and molecular genetic markers. Metabolism plays a critical role in glioma biology, as tumor cells rely heavily on altered metabolic pathways to support their rapid growth, survival, and progression. Dysregulated metabolic processes, involving carbohydrates, lipids, and amino acids not only fuel tumor development but also contribute to therapy resistance and metastatic potential. By understanding these metabolic changes, key intervention points, such as mutations in genes like RTK, EGFR, RAS, and IDH can be identified, paving the way for novel therapeutic strategies. This review emphasizes the connection between metabolic pathways and clinical challenges, offering actionable insights for future research and therapeutic development in gliomas.

A Data-Driven Approach Identifies Subtypes of Caries From Dental Charting

OBJECTIVES

The objectives were to: (i) assess the accuracy of dental data for adults obtained from the Swedish Quality Register on Caries and Periodontitis (SKaPa); (ii) explore whether Latent Class Analysis (LCA) can identify groups of people based on caries data; and (iii) characterise the dental, medical and behavioural characteristics of people in the LCA-derived classes.

METHODS

Caries data from the SKaPa register were compared with clinical data collected by five experienced dentists in a nested subgroup of the Malmö Offspring Study (MOS), namely the Malmö Offspring Dental Study (MODS) (n = 724) for validation. Dental data from SKaPa were then used to classify 61 984 adult participants of the Västerbotten Intervention Programme (VIP) into five classes using LCA and DMFS-based quintile ranking, respectively. Dental status (including caries progression over 5 years), medical, anthropometric and behavioural characteristics were compared between the groups. Analyses were replicated in 2767 adults in the MOS.

RESULTS

DMFS-scores and number of teeth recorded within -2 to +2 years showed excellent agreement between the SKaPa and reference data with intra-class correlations > 0.90. The five LCA classes differed in mean DMFS from 10.0 to 94.4. There were strong associations between LCA class and health, and health and behavioural measures respectively, including some associations that were not detected using DMFS-ranked quintile groups. LCA class was associated with incremental change in DMFS, DFS, and number of teeth. The results in the MOS cohort were consistent with the results in the VIP cohort.

CONCLUSIONS

Dental data for adults from the SKaPa registry were considered accurate within 2 years of recording. The LCA approach can classify participants into caries subtypes based on dental charting. These groups differ in health and behavioural characteristics and future caries increment. The LCA approach may capture some information that is missing from DMFS-ranked quintile groups, but is also heavily influenced by total DMFS, meaning that applying LCA in cumulative, highly age-determined diseases, such as caries, is a challenge.

SUMOylation modification of HNRNPK at the K422 site promotes invasion in glioblastoma

Glioblastoma multiforme (GBM) is a highly heterogeneous brain tumor with limited treatment options. Recent studies revealed cellular heterogeneity and the potential for interconversion between distinct cell types on the basis of RNA sequencing and single-cell analyses. The ability of different cell types to adapt to their surrounding environment and undergo transformation significantly complicates the study and treatment of GBM. In this study, we reveal that HNRNPK-SUMO1 expression is predominantly found in the GBM infiltration area. SUMOylation of the K422 residue of HNRNPK interferes with its DNA binding ability, thereby disrupting downstream transcription, and ultimately leading to transitions between different states of glioblastoma stem cells. Although the proneural subtype is considered to have a better prognosis, transitioning towards this state promotes tumor invasion. These findings serve as a reminder to exercise caution when considering treatments targeting specific cellular subtypes.

Cell Fate Dynamics Reconstruction Identifies TPT1 and PTPRZ1 Feedback Loops as Master Regulators of Differentiation in Pediatric Glioblastoma-Immune Cell Networks

Pediatric glioblastoma is a complex dynamical disease that is difficult to treat due to its multiple adaptive behaviors driven largely by phenotypic plasticity. Integrated data science and network theory pipelines offer novel approaches to studying glioblastoma cell fate dynamics, particularly phenotypic transitions over time. Here we used various single-cell trajectory inference algorithms to infer signaling dynamics regulating pediatric glioblastoma-immune cell networks. We identified GATA2, PTPRZ1, TPT1, MTRNR2L1/2, OLIG1/2, SOX11, FXYD6, SEZ6L, PDGFRA, EGFR, S100B, WNT, TNF α , and NF-kB as critical transition genes or signals regulating glioblastoma-immune network dynamics, revealing potential clinically relevant targets. Further, we reconstructed glioblastoma cell fate attractors and found complex bifurcation dynamics within glioblastoma phenotypic transitions, suggesting that a causal pattern may be driving glioblastoma evolution and cell fate decision-making. Together, our findings have implications for developing targeted therapies against glioblastoma, and the continued integration of quantitative approaches and artificial intelligence (AI) to understand pediatric glioblastoma tumor-immune interactions.

The translatome of glioblastoma

Glioblastoma (GB), the most common and aggressive brain tumor, demonstrates intrinsic resistance to current therapies, resulting in poor clinical outcomes. Cancer progression can be partially attributed to the deregulation of protein translation mechanisms that drive cancer cell growth. In this study, we present the translatome landscape of GB as a valuable data resource. Eight patient-derived GB sphere cultures (GSCs) were analyzed using ribosome profiling and messenger RNA (mRNA) sequencing. We investigated inter-cell-line differences through differential expression analysis at both the translatome and transcriptome levels. Translational changes post-radiotherapy were assessed at 30 and 60 min. The translation of non-coding RNAs (ncRNAs) was validated using in-house and public mass spectrometry (MS) data, whereas RNA expression was confirmed by quantitative PCR (qPCR). Our findings demonstrate that ribosome sequencing provides more detailed information than MS or transcriptional analyses. Transcriptional similarities among GSCs correlate with translational similarities, aligning with previously defined subtypes such as proneural and mesenchymal. Additionally, we identified a broad spectrum of open reading frame types in both coding and non-coding mRNA regions, including long non-coding RNAs (lncRNAs) and pseudogenes undergoing active translation. Translation of ncRNAs into peptides was independently confirmed by in-house data and external MS data. We also observed that translational regulation of histones (downregulated) and splicing factors (upregulated) occurs in response to radiotherapy. These data offer new insights into genome-wide protein synthesis, identifying translationally regulated genes and alternative translation initiation sites in GB under normal and radiotherapeutic conditions, providing a rich resource for GB research. Further functional validation of differentially expressed genes after radiotherapy is needed. Understanding translational control in GB can reveal mechanistic insights and identify currently unknown biomarkers, ultimately enhancing the diagnosis and treatment of this aggressive brain cancer.

Nrf2/Keap1/ARE regulation by plant secondary metabolites: a new horizon in brain tumor management

Brain cancer is regarded as one of the most life-threatening forms of cancer worldwide. Oxidative stress acts to derange normal brain homeostasis, thus is involved in carcinogenesis in brain. The Nrf2/Keap1/ARE pathway is an important signaling cascade responsible for the maintenance of redox homeostasis, and regulation of anti-inflammatory and anticancer activities by multiple downstream pathways. Interestingly, Nrf2 plays a somewhat, contradictory role in cancers, including brain cancer. Nrf2 has traditionally been regarded as a tumor suppressor since its cytoprotective functions are considered to be the principle cellular defense mechanism against exogenous and endogenous insults, such as xenobiotics and oxidative stress. However, hyperactivation of the Nrf2 pathway supports the survival of normal as well as malignant cells, protecting them against oxidative stress, and therapeutic agents. Plants possess a pool of secondary metabolites with potential chemotherapeutic/chemopreventive actions. Modulation of Nrf2/ARE and downstream activities in a Keap1-dependant manner, with the aid of plant-derived secondary metabolites exhibits promise in the management of brain tumors. Current article highlights the effects of Nrf2/Keap1/ARE cascade on brain tumors, and the potential role of secondary metabolites regarding the management of the same.

Integrated electrophysiological and genomic profiles of single cells reveal spiking tumor cells in human glioma

Prior studies have described the complex interplay that exists between glioma cells and neurons; however, the electrophysiological properties endogenous to glioma cells remain obscure. To address this, we employed Patch-sequencing (Patch-seq) on human glioma specimens and found that one-third of patched cells in IDH mutant (IDHmut) tumors demonstrate properties of both neurons and glia. To define these hybrid cells (HCs), which fire single, short action potentials, and discern if they are of tumoral origin, we developed the single cell rule association mining (SCRAM) computational tool to annotate each cell individually. SCRAM revealed that HCs possess select features of GABAergic neurons and oligodendrocyte precursor cells, and include both tumor and non-tumor cells. These studies characterize the combined electrophysiological and molecular properties of human glioma cells and describe a cell type in human glioma with unique electrophysiological and transcriptomic properties that may also exist in the non-tumor brain.

Spatiotemporal modeling reveals high-resolution invasion states in glioblastoma

BACKGROUND

Diffuse invasion of glioblastoma cells through normal brain tissue is a key contributor to tumor aggressiveness, resistance to conventional therapies, and dismal prognosis in patients. A deeper understanding of how components of the tumor microenvironment (TME) contribute to overall tumor organization and to programs of invasion may reveal opportunities for improved therapeutic strategies.

RESULTS

Towards this goal, we apply a novel computational workflow to a spatiotemporally profiled GBM xenograft cohort, leveraging the ability to distinguish human tumor from mouse TME to overcome previous limitations in the analysis of diffuse invasion. Our analytic approach, based on unsupervised deconvolution, performs reference-free discovery of cell types and cell activities within the complete GBM ecosystem. We present a comprehensive catalogue of 15 tumor cell programs set within the spatiotemporal context of 90 mouse brain and TME cell types, cell activities, and anatomic structures. Distinct tumor programs related to invasion align with routes of perivascular, white matter, and parenchymal invasion. Furthermore, sub-modules of genes serving as program network hubs are highly prognostic in GBM patients.

CONCLUSION

The compendium of programs presented here provides a basis for rational targeting of tumor and/or TME components. We anticipate that our approach will facilitate an ecosystem-level understanding of the immediate and long-term consequences of such perturbations, including the identification of compensatory programs that will inform improved combinatorial therapies.

Integrated bioinformatics analysis and experimental validation on malignant progression and immune cell infiltration of LTBP2 in gliomas

BACKGROUND

Gliomas are the highly aggressive brain tumor and also the most devastating human tumors. The latent TGF binding proteins (LTBP) had been found to be involved in malignant biological process and could be used as potent biomarkers in several solid tumors. While the role of LTBP family in human glioma remain to be elucidated.

METHODS

Normalized gene expression and corresponding clinical data of 2407 gliomas samples in public datasets were downloaded from Gliovis. Kaplan-Meier methods and Cox regression analysis was used for survival analyses.Western blot (WB) and Immunohistochemical (IHC) testing were employed to test LTBPs protein level in 154 gliomas samples. Correlation between LTBP2 expression and immune infiltration was evaluated by immunofluorescence (IF) and IHC in glioma tissues. CCK8 and flow cytometric analysis were used to detect the effect of LTBP2 on glioma cells. Orthotopic glioma- mouse models were utilized to evaluate effects in vivo.

RESULTS

LTBP2 mRNA level was dramatically higher in glioma samples compared with non-tumor brain tissues in XENA-TCGA_GTEx, Gill and Gravendeel datasets (all P < 0.01), and its expression positively correlated with glioma WHO grade, IDH1/2 wildtype and mesenchymal subtypes. These results were confirmed by In-house cohort which was detected by WB and IHC. We found that gliomas patients with high LTBP2 level had shorter OS than those with low LTBP2 level. LTBP2 expression significantly associated with glioma immune score (Spearman r = 0.68, P < 0.01)) and strongly correlated with infiltration degreee of macrophages both in lower grade gliomas (LGG) and GBM. Knocking down LTBP2 obviously reduced proliferation and enhanced sensitivity to temozolomide in U87 and U251 cells. Nude mice with lower expression of LTBP2 had slower tumor growth, and accompanied by less tumor-associated macrophages (TAMs) infiltration detected by IHC staining in vivo. Finally, low LTBP2 expression glioma patients who received chemotherapy survived longer than patients with high LTBP2 expression.

CONCLUSION

LTBP2 could be used as a prognostic marker, and high LTBP2 expression related to abundant TAMs infiltration and with a worse response to chemotherapy.

The mutated in colorectal cancer (MCC) gene can serve as a potential biomarker of glioblastoma

Introduction

The mutated in colorectal cancer (MCC) gene was initially identified as a candidate tumor suppressor gene in colorectal cancer, acting as a negative regulator of cell cycle progression. However, its functional roles in brain tumors, particularly glioblastoma, remain largely unexplored. This study reveals a significant association between MCC status and glioblastoma.

Methods

We explored MCC expression in the glioblastoma database, patient samples, and cell lines. We investigated the proliferation and migration of the cell lines in MCC gene knockdown using small interfering RNA.

Results

In vitro analyses revealed elevated protein and mRNA levels of MCC in several glioblastoma cell lines (U118MG and T98G). Silencing MCC expression via siRNA-mediated knockdown resulted in increased proliferation and migration of these cell lines. Supporting these findings, analyses of The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), and Genotype-Tissue Expression (GTEx) databases confirmed higher MCC expression in glioblastoma tumors than in normal brain tissue. Importantly, we observed that high MCC expression was associated with poor prognosis in glioblastoma patients, highlighting its potential role in disease progression. Additionally, this study identifies a nuclear localization of MCC in the glioblastoma cell line.

Discussion

These findings indicate that MCC expression is significantly upregulated in glioblastoma and may play a role in its pathophysiology, warranting further investigation.

Glioblastoma and Immune Checkpoint Inhibitors: A Glance at Available Treatment Options and Future Directions

Glioblastoma is known to be one of the most aggressive and fatal human cancers, with a poor prognosis and resistance to standard treatments. In the last few years, many solid tumor treatments have been revolutionized with the help of immunotherapy. However, this type of treatment has failed to improve the results in glioblastoma patients. Effective immunotherapeutic strategies may be developed after understanding how glioblastoma achieves tumor-mediated immune suppression in both local and systemic landscapes. Biomarkers may help identify patients most likely to benefit from this type of treatment. In this review, we discuss the use of immunotherapy in glioblastoma, with an emphasis on immune checkpoint inhibitors and the factors that influence clinical response. A Pubmed data search was performed for all existing information regarding immune checkpoint inhibitors used for the treatment of glioblastoma. All data evaluating the ongoing clinical trials involving the use of ICIs either as monotherapy or in combination with other drugs was compiled and analyzed.

Challenges and Outlooks in Precision Medicine: Expectations Versus Reality

Recent developments in technology have led to rapid advances in precision medicine, especially due to the rise of next-generation sequencing and molecular profiling. These technological advances have led to rapid advances in research, including increased tumor subtype resolution, new therapeutic agents, and mechanistic insights. Certain therapies have even been approved for molecular biomarkers across histopathological diagnoses; however, translation of research findings to the clinic still faces a number of challenges. In this review, the authors discuss several key challenges to the clinical integration of precision medicine, including the blood-brain barrier, both a lack and excess of molecular targets, and tumor heterogeneity/escape from therapy. They also highlight a few key efforts to address these challenges, including new frontiers in drug delivery, a rapidly expanding treatment repertoire, and improvements in active response monitoring. With continued improvements and developments, the authors anticipate that precision medicine will increasingly become the gold standard for clinical care.

Targeting axonal guidance dependencies in glioblastoma with ROBO1 CAR T cells

Resistance to genotoxic therapies and tumor recurrence are hallmarks of glioblastoma (GBM), an aggressive brain tumor. In this study, we investigated functional drivers of post-treatment recurrent GBM through integrative genomic analyses, genome-wide genetic perturbation screens in patient-derived GBM models and independent lines of validation. Specific genetic dependencies were found consistent across recurrent tumor models, accompanied by increased mutational burden and differential transcript and protein expression compared to its primary GBM predecessor. Our observations suggest a multi-layered genetic response to drive tumor recurrence and implicate PTP4A2 (protein tyrosine phosphatase 4A2) as a modulator of self-renewal, proliferation and tumorigenicity in recurrent GBM. Genetic perturbation or small-molecule inhibition of PTP4A2 acts through a dephosphorylation axis with roundabout guidance receptor 1 (ROBO1) and its downstream molecular players, exploiting a functional dependency on ROBO signaling. Because a pan-PTP4A inhibitor was limited by poor penetrance across the blood-brain barrier in vivo, we engineered a second-generation chimeric antigen receptor (CAR) T cell therapy against ROBO1, a cell surface receptor enriched across recurrent GBM specimens. A single dose of ROBO1-targeted CAR T cells doubled median survival in cell-line-derived xenograft (CDX) models of recurrent GBM. Moreover, in CDX models of adult lung-to-brain metastases and pediatric relapsed medulloblastoma, ROBO1 CAR T cells eradicated tumors in 50-100% of mice. Our study identifies a promising multi-targetable PTP4A-ROBO1 signaling axis that drives tumorigenicity in recurrent GBM, with potential in other malignant brain tumors.

Unveiling the Molecular Mechanisms of Glioblastoma through an Integrated Network-Based Approach

Background/Objectives: Despite current treatments extending the lifespan of Glioblastoma (GBM) patients, the average survival time is around 15-18 months, underscoring the fatality of GBM. This study aims to investigate the impact of sample heterogeneity on gene expression in GBM, identify key metabolic pathways and gene modules, and explore potential therapeutic targets. Methods: In this study, we analysed GBM transcriptome data derived from The Cancer Genome Atlas (TCGA) using genome-scale metabolic models (GEMs) and co-expression networks. We examine transcriptome data incorporating tumour purity scores (TPSs), allowing us to assess the impact of sample heterogeneity on gene expression profiles. We analysed the metabolic profile of GBM by generating condition-specific GEMs based on the TPS group. Results: Our findings revealed that over 90% of genes showing brain and glioma specificity in RNA expression demonstrate a high positive correlation, underscoring their expression is dominated by glioma cells. Conversely, negatively correlated genes are strongly associated with immune responses, indicating a complex interaction between glioma and immune pathways and non-tumorigenic cell dominance on gene expression. TPS-based metabolic profile analysis was supported by reporter metabolite analysis, highlighting several metabolic pathways, including arachidonic acid, kynurenine and NAD pathway. Through co-expression network analysis, we identified modules that significantly overlap with TPS-correlated genes. Notably, SOX11 and GSX1 are upregulated in High TPS, show a high correlation with TPS, and emerged as promising therapeutic targets. Additionally, NCAM1 exhibits a high centrality score within the co-expression module, which shows a positive correlation with TPS. Moreover, LILRB4, an immune-related gene expressed in the brain, showed a negative correlation and upregulated in Low TPS, highlighting the importance of modulating immune responses in the GBM mechanism. Conclusions: Our study uncovers sample heterogeneity's impact on gene expression and the molecular mechanisms driving GBM, and it identifies potential therapeutic targets for developing effective treatments for GBM patients.

Feeding the wrath with myelin

Kloosterman and colleagues studied molecular and cellular changes during radiation therapy and disease recurrence across molecular subtypes of glioblastoma. They uncovered a distinct immune-cancer cell metabolic crosstalk during proneural/oligodendrocyte progenitor cell-like to mesenchymal-like transition, wherein macrophages feed on cholesterol-rich myelin debris to provide lipids to mesenchymal tumor cells, thereby fueling glioblastoma growth.

O-GlcNAcylation promotes malignancy and cisplatin resistance of lung cancer by stabilising NRF2

BACKGROUND

The transcription factor NRF2 plays a significant role in regulating genes that protect cells from oxidative damage. O-GlcNAc modification, a type of posttranslational modification, is crucial for cellular response to stress. Although the involvement of both NRF2 and O-GlcNAc in maintaining cellular redox balance and promoting cancer malignancy has been demonstrated, the potential mechanisms remain elusive.

METHODS

The immunoblotting, luciferase reporter, ROS assay, co-immunoprecipitation, and immunofluorescence was used to detect the effects of global cellular O-GlcNAcylation on NRF2. Mass spectrometry was utilised to map the O-GlcNAcylation sites on NRF2, which was validated by site-specific mutagenesis and O-GlcNAc enzymatic labelling. Human lung cancer samples were employed to verify the association between O-GlcNAc and NRF2. Subsequently, the impact of NRF2 O-GlcNAcylation in lung cancer malignancy and cisplatin resistance were evaluated in vitro and in vivo.

RESULTS

NRF2 is O-GlcNAcylated at Ser103 residue, which hinders its binding to KEAP1 and thus enhances its stability, nuclear localisation, and transcription activity. Oxidative stress and cisplatin can elevate the phosphorylation of OGT at Thr444 through the activation of AMPK kinase, leading to enhanced binding of OGT to NRF2 and subsequent elevation of NRF2 O-GlcNAcylation. Both in cellular and xenograft mouse models, O-GlcNAcylation of NRF2 at Ser103 promotes the malignancy of lung cancer. In human lung cancer tissue samples, there was a significant increase in global O-GlcNAcylation, and elevated levels of NRF2 and its O-GlcNAcylation compared to paired adjacent normal tissues. Chemotherapy promotes NRF2 O-GlcNAcylation, which in turn decreases cellular ROS levels and drives lung cancer cell survival.

CONCLUSION

Our findings indicate that OGT O-GlcNAcylates NRF2 at Ser103, and this modification plays a role in cellular antioxidant, lung cancer malignancy, and cisplatin resistance.

Nod-like receptors: The relevant elements of glioblastoma`s prognostic puzzle

Despite considerable improvements in understanding the biology of glioblastoma (GB), it still remains the most lethal type of brain tumor in adults. The role of innate immune cells in the development of GB was recently described. In particular, the tumor-immune cell interactions are thought to be critical in enabling tumor tolerance and even protection against therapeutics. Interestingly, the GB cells express proteins belonging to the family of intracellular pattern-recognition receptors, namely the NOD-like receptors (NLRs). Their activation may trigger the formation of the inflammasome complex leading to the secretion of mature IL-1β and IL-18 and thus resulting in cell death. Intrudingly, the expression of most NLRs was found to be correlated with tumor progression and poor prognosis. We speculate that recognizing the role of NOD-like receptors in GB has the potential to improve the effectiveness of diagnostic tools and prognosis, while also encouraging the development of novel precision medicine-based therapies.

Advancing glioblastoma treatment through iron metabolism: A focus on TfR1 and Ferroptosis innovations

Glioblastoma (GBM) represents a formidable challenge in oncology, characterized by aggressive proliferation and poor prognosis. Iron metabolism plays a critical player in GBM progression, with dysregulated iron uptake and utilization contributing to tumor growth and therapeutic resistance. Iron's pivotal role in DNA synthesis, oxidative stress, and angiogenesis underscores its significance in GBM pathogenesis. Elevated expression of iron transporters, such as transferrin receptor 1 (TfR1), highlights the tumor's reliance on iron for survival. Innovative treatment strategies targeting iron dysregulation hold promise for overcoming therapeutic challenges in GBM management. Approaches such as iron chelation therapies, induction of ferroptosis to nanoparticle-based drug delivery systems exploit iron-dependent vulnerabilities, offering avenues for enhance treatment efficacy and improve patient outcomes. As research advances, understanding the complexities of iron-mediated carcinogenesis provides a foundation for developing precision medicine approaches tailored to combat GBM effectively. This review explores the intricate relationship between iron metabolism and GBM, elucidating its multifaceted implications and therapeutic opportunities. By consolidating the latest insights into iron metabolism in GBM, this review underscores its potential as a therapeutic target for improving patient care in combination with the standard of care approach.

Radiogenomics as an Integrated Approach to Glioblastoma Precision Medicine

PURPOSE OF REVIEW

Isocitrate dehydrogenase wild-type glioblastoma is the most aggressive primary brain tumour in adults. Its infiltrative nature and heterogeneity confer a dismal prognosis, despite multimodal treatment. Precision medicine is increasingly advocated to improve survival rates in glioblastoma management; however, conventional neuroimaging techniques are insufficient in providing the detail required for accurate diagnosis of this complex condition.

RECENT FINDINGS

Advanced magnetic resonance imaging allows more comprehensive understanding of the tumour microenvironment. Combining diffusion and perfusion magnetic resonance imaging to create a multiparametric scan enhances diagnostic power and can overcome the unreliability of tumour characterisation by standard imaging. Recent progress in deep learning algorithms establishes their remarkable ability in image-recognition tasks. Integrating these with multiparametric scans could transform the diagnosis and monitoring of patients by ensuring that the entire tumour is captured. As a corollary, radiomics has emerged as a powerful approach to offer insights into diagnosis, prognosis, treatment, and tumour response through extraction of information from radiological scans, and transformation of these tumour characteristics into quantitative data. Radiogenomics, which links imaging features with genomic profiles, has exhibited its ability in characterising glioblastoma, and determining therapeutic response, with the potential to revolutionise management of glioblastoma. The integration of deep learning algorithms into radiogenomic models has established an automated, highly reproducible means to predict glioblastoma molecular signatures, further aiding prognosis and targeted therapy. However, challenges including lack of large cohorts, absence of standardised guidelines and the 'black-box' nature of deep learning algorithms, must first be overcome before this workflow can be applied in clinical practice.

Comprehensive Bioinformatics Analysis Reveals the Potential Role of the hsa_circ_0001081/miR-26b-5p Axis in Regulating COL15A1 and TRIB3 within Hypoxia-Induced miRNA/mRNA Networks in Glioblastoma Cells

Background/Objectives: The intrinsic molecular heterogeneity of glioblastoma (GBM) is one of the main reasons for its resistance to conventional treatment. Mesenchymal GBM niches are associated with hypoxic signatures and a negative influence on patients' prognosis. To date, competing endogenous RNA (ceRNA) networks have been shown to have a broad impact on the progression of various cancers. In this study, we decided to construct hypoxia-specific microRNA/ messengerRNA (miRNA/mRNA) networks with a putative circular RNA (circRNA) regulatory component using available bioinformatics tools. Methods: For ceRNA network construction, we combined publicly available data deposited in the Gene Expression Omnibus (GEO) and interaction pairs obtained from miRTarBase and circBank; a differential expression analysis of GBM cells was performed with limma and deseq2. For the gene ontology (GO) enrichment analysis, we utilized clusterProfiler; GBM molecular subtype analysis was performed in the Glioma Bio Discovery Portal (Glioma-BioDP). Results: We observed that miR-26b-5p, generally considered a tumor suppressor, was upregulated under hypoxic conditions in U-87 MG cells. Moreover, miR-26b-5p could potentially inhibit TRIB3, a gene associated with tumor proliferation. Protein-protein interaction (PPI) network and GO enrichment analyses identified a hypoxia-specific subcluster enriched in collagen-associated terms, with six genes highly expressed in the mesenchymal glioma group. This subcluster included hsa_circ_0001081/miR-26b-5p-affected COL15A1, a gene downregulated in hypoxic U-87 MG cells yet highly expressed in the mesenchymal GBM subtype. Conclusions: The interplay between miR-26b-5p, COL15A1, and TRIB3 suggests a complex regulatory mechanism that may influence the extracellular matrix composition and the mesenchymal transformation in GBM. However, the precise impact of the hsa_circ_0001081/miR-26b-5p axis on collagen-associated processes in hypoxia-induced GBM cells remains unclear and warrants further investigation.

Defining heritability, plasticity, and transition dynamics of cellular phenotypes in somatic evolution

Single-cell sequencing has characterized cell state heterogeneity across diverse healthy and malignant tissues. However, the plasticity or heritability of these cell states remains largely unknown. To address this, we introduce PATH (phylogenetic analysis of trait heritability), a framework to quantify cell state heritability versus plasticity and infer cell state transition and proliferation dynamics from single-cell lineage tracing data. Applying PATH to a mouse model of pancreatic cancer, we observed heritability at the ends of the epithelial-to-mesenchymal transition spectrum, with higher plasticity at more intermediate states. In primary glioblastoma, we identified bidirectional transitions between stem- and mesenchymal-like cells, which use the astrocyte-like state as an intermediary. Finally, we reconstructed a phylogeny from single-cell whole-genome sequencing in B cell acute lymphoblastic leukemia and delineated the heritability of B cell differentiation states linked with genetic drivers. Altogether, PATH replaces qualitative conceptions of plasticity with quantitative measures, offering a framework to study somatic evolution.

Co-culture models for investigating cellular crosstalk in the glioma microenvironment

Glioma is the most prevalent primary malignant tumor in the central nervous system (CNS). It represents a diverse group of brain malignancies characterized by the presence of various cancer cell types as well as an array of noncancerous cells, which together form the intricate glioma tumor microenvironment (TME). Understanding the interactions between glioma cells/glioma stem cells (GSCs) and these noncancerous cells is crucial for exploring the pathogenesis and development of glioma. To invesigate these interactions requires in vitro co-culture models that closely mirror the actual TME in vivo. In this review, we summarize the two- and three-dimensional in vitro co-culture model systems for glioma-TME interactions currently available. Furthermore, we explore common glioma-TME cell interactions based on these models, including interactions of glioma cells/GSCs with endothelial cells/pericytes, microglia/macrophages, T cells, astrocytes, neurons, or other multi-cellular interactions. Together, this review provides an update on the glioma-TME interactions, offering insights into glioma pathogenesis.

Clinical implications of cytomegalovirus in glioblastoma progression and therapy

Glioblastoma (GBM) is one of the deadliest brain cancers with a median survival of only 15 months. This poor prognosis has prompted exploration of novel therapeutic targets for GBM patients. Human cytomegalovirus (HCMV) has been implicated in GBM; however, its impact remains poorly defined, and there is conflicting data over the presence of HCMV in tumors. Nonetheless, clinical trials targeting HCMV have shown promising initial data, and evidence suggests that HCMV may negatively impact GBM patient survival by multiple mechanisms including changes in GBM cell behavior and the tumor microenvironment (TME) that potentiate tumor progression as well as therapy-induced virus reactivation. Moreover, HCMV has many effects on host immunity that could impact tumor behavior by altering the TME, which are largely unexplored. The goal of this review is to describe these potential interactions between HCMV and GBM. Better understanding of these processes may allow the development of new therapeutic modalities to improve GBM patient outcomes.

Suppressive immune microenvironment and CART therapy for glioblastoma: Future prospects and challenges

Glioblastoma, a highly malignant intracranial tumor, has acquired slow progress in treatment. Previous clinical trials involving targeted therapy and immune checkpoint inhibitors have shown no significant benefits in treating glioblastoma. This ineffectiveness is largely due to the complex immunosuppressive environment of glioblastoma. Glioblastoma cells exhibit low immunogenicity and strong heterogeneity and the immune microenvironment is replete with inhibitory cytokines, numerous immunosuppressive cells, and insufficient effective T cells. Fortunately, recent Phase I clinical trials of CART therapy for glioblastoma have confirmed its safety, with a small subset of patients achieving survival benefits. However, CART therapy continues to face challenges, including blood-brain barrier obstruction, antigen loss, and an immunosuppressive tumor microenvironment (TME). This article provides a detailed examination of glioblastoma's immune microenvironment, both from intrinsic and extrinsic tumor cell factors, reviews current clinical and basic research on multi-targets CART treatment, and concludes by outlining the key challenges in using CART cells for glioblastoma therapy.

Muscarinic receptor drug trihexyphenidyl can alter growth of mesenchymal glioblastoma in vivo

Glioblastoma (GBM) is the most commonly occurring and most aggressive primary brain tumor. Transcriptomics-based tumor subtype classification has established the mesenchymal lineage of GBM (MES-GBM) as cancers with particular aggressive behavior and high levels of therapy resistance. Previously it was show that Trihexyphenidyl (THP), a market approved M1 muscarinic receptor-targeting oral drug can suppress proliferation and survival of GBM stem cells from the classical transcriptomic subtype. In a series of in vitro experiments, this study confirms the therapeutic potential of THP, by effectively suppressing the growth, proliferation and survival of MES-GBM cells with limited effects on non-tumor cells. Transcriptomic profiling of treated cancer cells identified genes and associated metabolic signaling pathways as possible underlying molecular mechanisms responsible for THP-induced effects. In vivo trials of THP in immunocompromised mice carry orthotopic MES-GBMs showed moderate response to the drug. This study further highlights the potential of THP repurposing as an anti-cancer treatment regimen but mode of action and d optimal treatment procedures for in vivo regimens need to be investigated further.

An ILK/STAT3 pathway controls glioblastoma stem cell plasticity

Glioblastoma (GBM) is driven by malignant neural stem-like cells that display extensive heterogeneity and phenotypic plasticity, which drive tumor progression and therapeutic resistance. Here, we show that the extracellular matrix-cell adhesion protein integrin-linked kinase (ILK) stimulates phenotypic plasticity and mesenchymal-like, invasive behavior in a murine GBM stem cell model. ILK is required for the interconversion of GBM stem cells between malignancy-associated glial-like states, and its loss produces cells that are unresponsive to multiple cell state transition cues. We further show that an ILK/STAT3 signaling pathway controls the plasticity that enables transition of GBM stem cells to an astrocyte-like state in vitro and in vivo. Finally, we find that ILK expression correlates with expression of STAT3-regulated proteins and protein signatures describing astrocyte-like and mesenchymal states in patient tumors. This work identifies ILK as a pivotal regulator of multiple malignancy-associated GBM phenotypes, including phenotypic plasticity and mesenchymal state.

Patient-derived tumor organoids mimic treatment-induced DNA damage response in glioblastoma

Glioblastoma (GB) is the most common primary malignant brain tumor, characterized by resistance to therapy. Despite aggressive treatment options, GB remains an incurable disease. Invasiveness and heterogeneity are key GB features that cannot be studied in preclinical in vitro models. In this study, we investigated the effects of standard therapy using patient-derived GB organoids (GBOs). GBOs reflect the complexity and heterogeneity of the original tumor tissue. No significant effect on GBO viability or invasion was observed after irradiation and temozolomide treatment. E3 ubiquitin-protein ligase (MDM2), cyclin-dependent kinase inhibitor 1A (CDKN1A), and the serine/threonine kinases ATM and ATR were upregulated at the gene and protein levels after treatment. Our results show that the p53 pathway and DNA-damage response mechanisms were triggered, suggesting that GBOs recapitulate GB therapy resistance. GBOs thus provide a highly efficient platform to assess the specific responses of GB patients to therapy and to further explore therapy resistance.

Magnetic Hyperthermia in Glioblastoma Multiforme Treatment

Glioblastoma multiforme (GBM) represents one of the most critical oncological diseases in neurological practice, being considered highly aggressive with a dismal prognosis. At a worldwide level, new therapeutic methods are continuously being researched. Magnetic hyperthermia (MHT) has been investigated for more than 30 years as a solution used as a single therapy or combined with others for glioma tumor assessment in preclinical and clinical studies. It is based on magnetic nanoparticles (MNPs) that are injected into the tumor, and, under the effect of an external alternating magnetic field, they produce heat with temperatures higher than 42 °C, which determines cancer cell death. It is well known that iron oxide nanoparticles have received FDA approval for anemia treatment and to be used as contrast substances in the medical imagining domain. Today, energetic, efficient MNPs are developed that are especially dedicated to MHT treatments. In this review, the subject's importance will be emphasized by specifying the number of patients with cancer worldwide, presenting the main features of GBM, and detailing the physical theory accompanying the MHT treatment. Then, synthesis routes for thermally efficient MNP manufacturing, strategies adopted in practice for increasing MHT heat performance, and significant in vitro and in vivo studies are presented. This review paper also includes combined cancer therapies, the main reasons for using these approaches with MHT, and important clinical studies on human subjects found in the literature. This review ends by describing the most critical challenges associated with MHT and future perspectives. It is concluded that MHT can be successfully and regularly applied as a treatment for GBM if specific improvements are made.

Microenvironmental regulation of tumor-associated neutrophils in malignant glioma: from mechanism to therapy

Glioma is the most common primary intracranial tumor in adults, with high incidence, recurrence, and mortality rates. Tumor-associated neutrophils (TANs) are essential components of the tumor microenvironment (TME) in glioma and play a crucial role in glioma cell proliferation, invasion and proneural-mesenchymal transition. Besides the interactions between TANs and tumor cells, the multi-dimensional crosstalk between TANs and other components within TME have been reported to participate in glioma progression. More importantly, several therapies targeting TANs have been developed and relevant preclinical and clinical studies have been conducted in cancer therapy. In this review, we introduce the origin of TANs and the functions of TANs in malignant behaviors of glioma, highlighting the microenvironmental regulation of TANs. Moreover, we focus on summarizing the TANs-targeted methods in cancer therapy, aiming to provide insights into the mechanisms and therapeutic opportunities of TANs in the malignant glioma microenvironment.

Catalytically distinct IDH1 mutants tune phenotype severity in tumor models

Mutations in isocitrate dehydrogenase 1 (IDH1) impart a neomorphic reaction that produces D-2-hydroxyglutarate (D2HG), which can inhibit DNA demethylases to drive tumorigenesis. Mutations affect residue R132 and display distinct catalytic profiles for D2HG production. We show that catalytic efficiency of D2HG production is greater in IDH1 R132Q than R132H mutants, and expression of R132Q in cellular and xenograft models leads to higher D2HG concentrations in cells, tumors, and sera compared to R132H. Though expression of IDH1 R132Q leads to hypermethylation in DNA damage pathways, DNA hypomethylation is more notable when compared to R132H expression. Transcriptome analysis shows increased expression of many pro-tumor pathways upon expression of IDH1 R132Q versus R132H, including transcripts of EGFR and PI3K signaling pathways. Thus, IDH1 mutants appear to modulate D2HG levels via altered catalysis, resulting in distinct epigenetic and transcriptomic consequences where higher D2HG levels appear to be associated with more aggressive tumors.

The multifaceted therapeutical role of low-density lipoprotein receptor family in high-grade glioma

The diverse roles of the low-density lipoprotein receptor family (LDLR) have been associated with many processes critical to maintaining central nervous system (CNS) health and contributing to neurological diseases or cancer. In this review, we provide a comprehensive understanding of the LDLR's involvement in common brain tumors, specifically high-grade gliomas, emphasizing the receptors' critical role in the pathophysiology and progression of these tumors due to LDLR's high expression. We delve into LDLR's role in regulating cellular uptake and transport through the brain barrier. Additionally, we highlight LDLR's role in activating several signaling pathways related to tumor proliferation, migration, and invasion, engaging readers with an in-depth understanding of the molecular mechanisms at play. By synthesizing current research findings, this review underscores the significance of LDLR during tumorigenesis and explores its potential as a therapeutic target for high-grade gliomas. The collective insights presented here contribute to a deeper appreciation of LDLR's multifaceted roles and implications for physiological and pathological states, opening new avenues for tumor treatment.

FACT inhibitor CBL0137, administered in an optimized schedule, potentiates radiation therapy for glioblastoma by suppressing DNA damage repair

PURPOSE

Standard-of-care for glioblastoma remains surgical debulking followed by temozolomide and radiation. However, many tumors become radio-resistant while radiation damages surrounding brain tissue. Novel therapies are needed to increase the effectiveness of radiation and reduce the required radiation dose. Drug candidate CBL0137 is efficacious against glioblastoma by inhibiting histone chaperone FACT, known to be involved in DNA damage repair. We investigated the combination of CBL0137 and radiation on glioblastoma.

METHODS

In vitro, we combined CBL0137 with radiation on U87MG and A1207 glioblastoma cells using the clonogenic assay to evaluate the response to several treatment regimens, and the Fast Halo Assay to examine DNA repair. In vivo, we used the optimum combination treatment regimen to evaluate the response of orthotopic tumors in nude mice.

RESULTS

In vitro, the combination of CBL0137 and radiation is superior to either alone and administering CBL0137 two hours prior to radiation, having the drug present during and for a prolonged period post-radiation, is an optimal schedule. CBL0137 inhibits DNA damage repair following radiation and affects the subcellular distribution of histone chaperone ATRX, a molecule involved in DNA repair. In vivo, one dose of CBL0137 is efficacious and the combination of CBL0137 with radiation increases median survival over either monotherapy.

CONCLUSIONS

CBL0137 is most effective with radiation for glioblastoma when present at the time of radiation, immediately after and for a prolonged period post-radiation, by inhibiting DNA repair caused by radiation. The combination leads to increased survival making it attractive as a dual therapy.

Glioblastoma cells increase expression of notch signaling and synaptic genes within infiltrated brain tissue

Glioblastoma remains one of the deadliest brain malignancies. First-line therapy consists of maximal surgical tumor resection, accompanied by chemotherapy and radiotherapy. Malignant cells escape surgical resection by migrating into the surrounding healthy brain tissue, where they give rise to the recurrent tumor. Based on gene expression, tumor cores can be subtyped into mesenchymal, proneural, and classical tumors, each being associated with differences in genetic alterations and cellular composition. In contrast, the adjacent brain parenchyma where infiltrating malignant cells escape surgical resection is less characterized in patients. Using spatial transcriptomics (n = 11), we show that malignant cells within proneural or mesenchymal tumor cores display spatially organized differences in gene expression, although such differences decrease within the infiltrated brain tissue. Malignant cells residing in infiltrated brain tissue have increased expression of genes related to neurodevelopmental pathways and glial cell differentiation. Our findings provide an updated view of the spatial landscape of glioblastomas and further our understanding of the malignant cells that infiltrate the healthy brain, providing new avenues for the targeted therapy of these cells after surgical resection.

Modulating voltage-gated sodium channels to enhance differentiation and sensitize glioblastoma cells to chemotherapy

BACKGROUND

Glioblastoma (GBM) stands as the most prevalent and aggressive form of adult gliomas. Despite the implementation of intensive therapeutic approaches involving surgery, radiation, and chemotherapy, Glioblastoma Stem Cells contribute to tumor recurrence and poor prognosis. The induction of Glioblastoma Stem Cells differentiation by manipulating the transcriptional machinery has emerged as a promising strategy for GBM treatment. Here, we explored an innovative approach by investigating the role of the depolarized resting membrane potential (RMP) observed in patient-derived GBM sphereforming cell (GSCs), which allows them to maintain a stemness profile when they reside in the G0 phase of the cell cycle.

METHODS

We conducted molecular biology and electrophysiological experiments, both in vitro and in vivo, to examine the functional expression of the voltage-gated sodium channel (Nav) in GSCs, particularly focusing on its cell cycle-dependent functional expression. Nav activity was pharmacologically manipulated, and its effects on GSCs behavior were assessed by live imaging cell cycle analysis, self-renewal assays, and chemosensitivity assays. Mechanistic insights into the role of Nav in regulating GBM stemness were investigated through pathway analysis in vitro and through tumor proliferation assay in vivo.

RESULTS

We demonstrated that Nav is functionally expressed by GSCs mainly during the G0 phase of the cell cycle, suggesting its pivotal role in modulating the RMP. The pharmacological blockade of Nav made GBM cells more susceptible to temozolomide (TMZ), a standard drug for this type of tumor, by inducing cell cycle re-entry from G0 phase to G1/S transition. Additionally, inhibition of Nav substantially influenced the self-renewal and multipotency features of GSCs, concomitantly enhancing their degree of differentiation. Finally, our data suggested that Nav positively regulates GBM stemness by depolarizing the RMP and suppressing the ERK signaling pathway. Of note, in vivo proliferation assessment confirmed the increased susceptibility to TMZ following pharmacological blockade of Nav.

CONCLUSIONS

This insight positions Nav as a promising prognostic biomarker and therapeutic target for GBM patients, particularly in conjunction with temozolomide treatment.

Structural insights into the role and targeting of EGFRvIII

The epidermal growth factor receptor (EGFR) is a well-known oncogenic driver in lung and other cancers. In glioblastoma multiforme (GBM), the EGFR deletion variant III (EGFRvIII) is frequently found alongside EGFR amplification. Agents targeting the EGFR axis have shown limited clinical benefits in GBM and the role of EGFRvIII in GBM is poorly understood. To shed light on the role of EGFRvIII and its potential as a therapeutic target, we determined X-ray crystal structures of a monomeric EGFRvIII extracellular region (ECR). The EGFRvIII ECR resembles the unliganded conformation of EGFR, including the orientation of the C-terminal region of domain II. Domain II is mostly disordered, but the ECR structure is compact. We selected a nanobody with preferential binding to EGFRvIII relative to EGFR and structurally defined an epitope on domain IV that is occluded in the unliganded intact EGFR. These findings suggest new avenues for EGFRvIII targeting in GBM.