Infiltrative Gliomas Research Articles

Foundation models for fast, label-free detection of glioma infiltration.

A critical challenge in glioma treatment is detecting tumour infiltration during surgery to achieve safe maximal resection1-3. Unfortunately, safely resectable residual tumour is found in the majority of patients with glioma after surgery, causing early recurrence and decreased survival4-6. Here we present FastGlioma, a visual foundation model for fast (<10 s) and accurate detection of glioma infiltration in fresh, unprocessed surgical tissue. FastGlioma was pretrained using large-scale self-supervision (around 4 million images) on rapid, label-free optical microscopy, and fine-tuned to output a normalized score that indicates the degree of tumour infiltration within whole-slide optical images. In a prospective, multicentre, international testing cohort of patients with diffuse glioma (n = 220), FastGlioma was able to detect and quantify the degree of tumour infiltration with an average area under the receiver operating characteristic curve of 92.1 ± 0.9%. FastGlioma outperformed image-guided and fluorescence-guided adjuncts for detecting tumour infiltration during surgery by a wide margin in a head-to-head, prospective study (n = 129). The performance of FastGlioma remained high across diverse patient demographics, medical centres and diffuse glioma molecular subtypes as defined by the World Health Organization. FastGlioma shows zero-shot generalization to other adult and paediatric brain tumour diagnoses, demonstrating the potential for our foundation model to be used as a general-purpose adjunct for guiding brain tumour surgeries. These findings represent the transformative potential of medical foundation models to unlock the role of artificial intelligence in the care of patients with cancer.

CNSC-65. ELECTROPHYSIOLOGICAL AND SPATIAL TRANSCRIPTOMIC PROFILING OF GLIOMA-INFILTRATED CORTEX REVEAL LAYER SPECIFIC ALTERATIONS

Abstract Specialized neocortical circuits selectively organize neuronal signals and encode features of cognitive processing via local and long-range connections. Since glioma-infiltrated cortex is excitable and can participate in cognitive processing, the underlying laminar structure and functionality may still be preserved despite infiltration. Moreover, since glioma cells remodel existing neural circuits and microenvironmental factors drive invasion and proliferation, neuron-glioma interactions may demonstrate layer specificity. As glioma-infiltrated cortex remains poorly understood, we sought to characterize these regions using electrophysiological, structural, and genomic approaches. We assessed the power spectra of normal-appearing and glioma-infiltrated cortex using magnetoencephalography and subdural high-density electrode arrays. Immunohistochemistry of formalin-fixed paraffin-embedded (FFPE) samples of infiltrated cortex enabled protein-level neuronal and glioma identification to determine laminar preservation and spatial invasion patterns. Spatial transcriptomics of FFPE tissues and single-nucleus RNA-sequencing were used to identify cell populations, genomic alterations, and cell-cell communication within and across samples at testing and validation sites across the US and Europe. Increased delta range (1-4 Hz) power and decreased power in the beta range (12-20 Hz), activity thought to originate from deep layers, were identified as robust features of infiltrated cortex which were maintained across glioma subtypes (n = 139 patients) and preserved in a validation cohort (n = 8 patients). Immunohistochemistry revealed greater tumor burden within deep laminae regardless of glioma subtype (n = 20 samples). Tissue proteomics and spatial genomics analyses performed using glioma-infiltrated cortical samples (n = 10 samples; 29,011 spots) confirmed routine preservation of laminar organization, greater tumor burden in deep layers, as well as layer specific differences in glioma-related expression programs. Cell-cell communication analyses demonstrated increased interactions in glioma-infiltrated cortex across layers. These findings suggest that laminar structure may be preserved in glioma-infiltrated cortex while remodeling of neural circuits alters spatiotemporal activity in a predictable manner and support a deep to superficial invasion pattern. Thus, investigating glioma infiltration using layer-centric approaches may facilitate novel insights into neuron-glioma interactions.

CNSC-59. EPIGENETIC POTENTIATION OF ANTI-TUMOR IMMUNE RESPONSES USING VIRAL MIMICRY IN GLIOMAS

Abstract Clinical trials using immune checkpoint inhibition(ICI) have traditionally failed in glioblastoma (GBM). Viral mimicry, which augments anti-tumor immune responses and sensitizes response to immunotherapy in other cancers, involves the epigenetic activation of endogenous retroelements (REs). REs are silenced via the HUSH complex and H3K9me3. This process is mediated by ZNF638. We aimed to elucidate the role of viral mimicry in enhancing ICI through epigenetic reprogramming of the HUSH complex. We demonstrated that RE expression among 48 superfamilies inversely correlated with ZNF638 expression in gliomas, based on data from 71 newly-diagnosed GBMs. Using transcriptional deconvolution, we showed ZNF638 negatively correlates with innate antiviral immune response signatures(TLR3)(RTLR3=-0.300,pTLR3=0.00006). We validated these in-silico results in pure glioma cell lines, patient-derived GBM neurospheres, and syngeneic murine models. ZNF638 knockdown induced intracellular RE-mediated dsRNA signaling cascades via RIG-I and TLR3. This knockdown significantly increased PD-L1 expression(p&amp;lt;0.001), reduced H3K9 trimethylation, and enhanced cytoplasmic dsRNA accumulation in glioma cell lines. In patient-derived GBM neurospheres, ZNF638 knockdown upregulated immune and antiviral programs. Additionally, knockdown resulted in upregulation of several endogenous repeat elements (Alu, LTR). Single-cell RNA sequencing showed ZNF638 clustering in neural progenitor-like and oligodendrocyte-like cells, with increased retroelement expression in low ZNF638 cells. Tumors with lower ZNF638 expression showed increased CD8+ populations. Bulk RNA sequencing deconvolution revealed that ZNF638 is linked to reduced CD8 and DC infiltration in gliomas (RCD8=-0.202,RDC=-0.198;pCD8=8.79E-06,pDC=1.34E-05). In immunocompetent mice, ZNF638 KO and PD-L1 inhibition significantly improved survival (mOS &amp;gt;50 days, p&amp;lt;0.0001) and reduced tumor volume (p&amp;lt;0.001). Analysis of cohorts from multiple cancer types treated with anti-PD1 therapy demonstrated that ZNF638 expression predicts therapeutic response and overall survival. Our findings suggest that epigenetic reprogramming through HUSH inhibition may potentiate immunotherapy for GBM.

NIMG-31. CASE REPORT: DIAGNOSIS OF AN INFILTRATIVE GLIOMA IN A LI-FRAUMENI SYNDROME PATIENT OBSCURED BY LESION RESPONSIVENESS TO NSCLC TREATMENT

Abstract Li-Fraumeni syndrome is a rare, autosomal dominant disorder linked to germline mutations of the TP53 suppressor gene. Patients with this syndrome are predisposed to various malignancies and a variety of brain tumors to include choroid plexus carcinoma, medulloblastoma, and glioma. We present a 46-year-old woman with a history of Li-Fraumeni syndrome which manifested with multiple systemic malignancies including breast cancer, ovarian teratoma, and leiomyosarcoma. The patient had been undergoing MRI brain surveillance since 2018, which was initially notable for a right cerebellar midline focus of enhancement associated with slowly evolving right middle cerebellar peduncle FLAIR signal, with no detectable neurologic symptoms. She underwent systemic therapy for non-small cell lung cancer (NSCLC) with pemetrexed/cisplatin. Her next MRI brain in August 2023 showed resolution of the cerebellar enhancement with small residual FLAIR signal. In April 2024, the patient presented with new neurologic symptoms to include ataxia, dizziness, difficulty swallowing, and memory loss. Repeat MRI brain revealed new infiltrative FLAIR signal throughout the right temporal lobe extending from the posterior fossa, contiguous with the previously seen cerebellar findings and consistent with infiltrative glioma. Due to fragmented records and care in multiple systems, her updated MRI initially created a diagnostic challenge with a radiographic interpretation of likely encephalitis. This is a unique case documenting a middle-aged female with Li-Fraumeni syndrome, followed for multiple cancers, presenting with new neurologic symptoms and progressive infiltrative FLAIR changes spanning from the cerebellum into the right temporal lobe. These findings highlight the natural history of a TP53 deficient tumor that ostensibly responded to a cisplatin-based regimen given for a different indication, thereby delaying time to symptom onset and need for biopsy. Surveillance of low grade lesions in patients with underlying tumor predisposition syndromes must be interpreted in context of systemic disease burden and concurrent treatments for other neoplasms.

BIOM-30. NOVEL HISTOLOGIC AND MOLECULAR BIOMARKERS FOR OLIGODENDROGLIOMA

Abstract Oligodendrogliomas are progressive, infiltrative gliomas. While new molecular criteria were introduced in 2016 for diagnosing oligodendroglioma, the grading criteria remains largely unchanged. We evaluated histologic and molecular features for new biomarkers of aggressive behavior, using a cohort of 184 specimens diagnosed as low grade oligodendroglioma within the Duke Brain Tumor Center Biorepository. To identify tumors meeting current molecular criteria for oligodendroglioma, IDH1/2 status was confirmed by whole exome sequencing and 1p/19q codeletion confirmed using inferred copy number variation. First, we assessed for a histologic feature called hypercellular nodules (HCN), which are foci of increased cellularity in regions of otherwise lower cellularity tumor. In patients with newly diagnosed grade 2 oligodendroglioma, 16% (15/92) had HCN. While the median overall survival (OS) was 24.1 years without HCN, the median OS with HCN was only 13.6 years (p&amp;lt;0.02, Mantel-Cox test). We then assessed for homozygous deletion of CDKN2A. Cases with potential CDKN2A homozygous deletion by inferred copy number variation were validated by fluorescence in situ hybridization. In patients with newly diagnosed grade 2 oligodendroglioma, 2% had homozygous CDKN2A deletion (2/107). While the median OS with intact or hemizygous CDKN2A loss was 21 years, it decreased to 3.8 years with homozygous CDKN2A deletion (p&amp;lt;0.0001, Mantel-Cox test), although interpretation is limited given the rarity of homozygous CDKN2A loss at initial diagnosis. For recurrent grade 2 oligodendroglioma, 6% had homozygous deletion (5/77). While the median OS with intact or hemizygous CDKN2A loss in recurrent oligodendroglioma was 25.4 years, it decreased to 6.7 years with homozygous CDKN2A deletion (p&amp;lt; 0.04, Mantel-Cox test). These studies provide support for using HCN and CDKN2A homozygous deletion as grading criteria for oligodendroglioma. Further studies are ongoing, including covariate analysis, expanded cohorts, and ongoing analysis of whole exome sequencing data to identify additional genetic alterations correlated with overall survival.

CNSC-19. ISCHEMIC STROKE DRIVES GLIOMA PROGRESSION BY REMODELING TUMOR-ASSOCIATED ASTROCYTES

Abstract Ischemic stroke and glioma are two deadly neurological disorders worldwide. Recent epidemiological studies reveal an increased risk of brain tumors, notably glioma, in patients with a history of stroke, resulting in a 10% co-occurrence. Comparative transcriptome analyses of brain samples collected from patients with common neurological disorders show that glioma is particularly enriched with stroke-associated gene signatures, especially in pathways related to their shared pathological features. These findings suggest a stroke-glioma interrelationship; however, it remains unknown how stroke alters the brain microenvironment to drive tumor progression. Here, we induced photothrombotic stroke in three mouse glioma models recapitulating multiple aspects of human glioma. Across all glioma models, we consistently observed that stroke increases tumor proliferation and infiltration towards stroke-affected regions, accompanied by reduced survival compared to sham control groups. Further analyses using single-cell RNA sequencing and spatial transcriptomic profiling in our stroke-glioma models reveal pronounced stroke-induced glioma microenvironment changes, among which tumor-associated astrocytes (TAAs) are most dramatically remodeled. Remarkably, we identified a unique stroke-induced astrocyte (SAA) at the tumor leading edge of the stroke-glioma group, characterized by diminished physiological astrocyte signatures and increased chromosomal and metabolic reprogramming. Among the top differentially expressed genes in SAA compared with TAA, the sodium-bicarbonate cotransporter Slc4a4 is interesting due to its enriched expression in TAA in both human and mouse gliomas, and it is significantly down-regulated at the infiltrating tumor edge. Consequently, we examine whether restoring astrocytic Slc4a4 expression rescues stroke-induced glioma progression. We found that astrocytic Slc4a4 overexpression reduces glioma growth and infiltration, accompanied by extended astroglial scar formation. Collectively, our study demonstrates that a subset of TAAs induced by stroke exacerbates glioma pathology, highlighting an indispensable astrocytic contribution to the stroke-glioma interaction.

Clotting promotes glioma growth and infiltration through activation of focal adhesion kinase.

The tumor architecture of high-grade gliomas is shaped by tumor cell necrosis, invasive growth and the leakage of a fibrin-rich edema from poorly organized tumor blood vessels. Here, we demonstrate a marked upregulation of clot formation in the interstitial spaces of tumor tissues from patients with glioblastoma while tumor-free brain is essentially devoid of fibrin. The accumulation of fibrin in tumor interstitial spaces is functionally relevant as we demonstrate increased infiltration and growth of primary glioblastoma cells after embedding in a 3-dimensional matrix made of fibrin ex vivo. Additionally, we detected accelerated tumor growth after implanting glioblastoma cells together with clotted plasma in brains of immune deficient mice while glioblastoma development in clotting-deficient hemophilia mice was delayed. Glioblastoma growth correlated with the outgrowth of invadopodia and their adhesive interactions with the 3-dimensional clot matrix, which was mediated by integrins β1 and β3 and their common downstream target focal adhesion kinase (FAK). Knocking down FAK with CRISPR Cas9 caused an upregulation of p21/p27 cell cycle inhibitors, strong growth inhibition in cultured glioblastoma cells and sustained anti-tumorigenic effects in orthotopic glioblastoma xenografts in vivo. These results go hand in hand with genomic data from The Cancer Genome Atlas that indicate increased clotting activity and reduced patient survival in glioma subgroups with high integrin β1 and β3 expression. We therefore conclude that clotting in glioma interstitial spaces provides tumor cells with a potent proliferative stimulus that can be reversed by targeting the adhesive machinery of glioblastoma cells via inhibition of FAK.

EPCO-07. INTEGRATING SPATIALLY RESOLVED MULTI-OMICS DATA TO UNCOVER DYSFUNCTIONAL METABOLISM DRIVEN NETWORKS THAT ENHANCE INFILTRATION OF DIFFUSE GLIOMAS

Abstract BACKGROUND Diffuse infiltration is an aggressive feature of high-grade gliomas with survival implications. The contribution of crosstalk between non-neoplastic and neoplastic cells to tumor infiltration remains largely understudied due to the lack of profiling techniques that retain spatial information. Spatial multi-omic profiling is a promising approach to comprehensively analyze transcript-omics, prote-omics and metabol-omics on the same tissue section while preserving information about the spatial organization of cells. Integration of these spatial studies allows for inferring the consequences of complex cell-cell communication underlying tumor infiltration. We hypothesize that the glioma edge is enriched with pro-infiltration ligands-receptors driving tumor infiltration. Strategies that disrupt these ligand-receptor networks may suppress glioma infiltration and improve clinical outcomes. METHODS We utilized a glioma tissue micro-array (TMA) to establish the neoplastic and non-neoplastic heterogeneity in the GBM infiltration edge. Each TMA slide consists of pathologist annotated tumor core and edge samples of Glioblastoma (IDH Wildtype, WHO Grade 4; n=10), Diffuse Astrocytoma (IDH Mutant, WHO Grade 3; n=3), Oligodendroglioma (IDH mutant, WHO Grade 2; n=5) and 2 non-brain control samples. We performed spatial multi-omics profiling on adjacent sections of the TMA using 10x Xenium spatial transcriptomics, imaging mass cytometry (IMC) and mass spectrometry imaging (MSI). Integration, visualization, and quantification of the spatial data was done on VisioPharm. RESULTS In GBM, we identified candidate mRNA transcripts and proteins for ligands enriched at the infiltrating edge (compared to tumor core; p&amp;lt;0.0001) that correlated with a poor progression free survival (PFS; r2=0.22). These candidate ligands were also significantly enriched at the edge of oligodendroglioma WHO Grade 2 and astrocytoma WHO Grade 3. CONCLUSIONS Spatial multi-omics profiling on a TMA consisting of Glioma WHO grades 2-4 identified differentially expressed and targetable pro-tumor infiltration ligands associated with lower PFS in GBM. Functional studies to uncover the role of metabolites enriched at the glioma edge for the expression of the identified pro-infiltration ligands are ongoing.

TMIC-34. INFILTRATIVE BEHAVIOR OF PATIENT-DERIVED GLIOBLASTOMA CELL LINES IN REGION-SPECIFIC HUMAN BRAIN ORGANOIDS

Abstract Glioblastoma (GBM) is the most common malignant brain tumor in adults. GBMs are known for their highly invasive and proliferative properties and are associated with a dismal prognosis (~12-18 months post-diagnosis). Neuroanatomical disparities in the occurrence of GBMs suggest that in addition to microenvironmental impacts, tumor cells are impacted by the cellular and molecular diversity across varying regions of this nervous system. This idea has been difficult to study due to the lack of human-specific models that effectively recapitulate the biological behaviors of GBMs in region-specific microenvironments. To address these challenges, we engrafted GFP-tagged patient-derived glioma cell lines into human induced pluripotent stem cell (hiPSC)-derived organoids patterned to mimic the most forebrain (dorsal cortex) and hindbrain (spinal cord) regions of the nervous system. Immunostaining assays at 2, 7, 14, and 21 days post-engraftment compared the extent of infiltration, as measured by the distance traveled by glioma cells, in both regions. We found that glioma cells infiltrated a significantly greater distance in the dorsal cortical organoids compared to the spinal cord organoids. This suggests a more conducive environment for glioma infiltration in the forebrain vs. hindbrain at baseline. We are currently determining if these regional biases in infiltration capacity are modified with either optogenetic stimulation of the host brain organoids or in the presence of interregional interactions in an assembloid system. Thus, using this fully human-specific platform, we aim to gain insights into the infiltrative behaviors of GBM cells, which will advance our understanding of this devastating disease.

Complement C1S is a potential prognostic biomarker and associated with M2 macrophage infiltration in gliomas: From bioinformatics to comprehensive experimental validation

Glioma is the most common malignant tumor of the central nervous system, and the ability of traditional clinical treatment to prolong the survival of glioma patients is limited. A substantial body of evidence underscores the pivotal role of the immune system in eradicating malignant cells and impeding tumor metastasis. Consequently, tumor immunotherapy has become a promising avenue to address the clinical conundrum faced by glioma patients. The complement system is a natural immune system that is an important line of defense in the immune response. C1S plays a key role in activating the classical complement system. Nevertheless, few studies have focused on the role of C1S in glioma tumorigenesis and progression. In this study, we demonstrated that C1S was upregulated in GBM (Grade IV) and low-grade gliomas (LGG, Grade II-III) by combining glioma cohorts from multiple public databases with our internal independent cohorts and that increased C1S expression levels predict a poor prognosis for gliomas. Cox regression analysis identified C1S as an important prognostic indicator for glioma patients. In addition, gene functional enrichment analysis demonstrated that C1S was involved in cellular immunity, T-cell activation, macrophage differentiation, and cell proliferation. Further experiments demonstrated that C1S facilitates tumor cell proliferation, cell migration and intracranial tumor growth in nude mice. More importantly, we evaluated the role of C1S in immune infiltration. These results suggested that C1S was closely related to a variety of immune cell types in glioma, especially M2 macrophages. Our findings were further validated via glioma tissue microarray immunohistochemical analysis and an M2 macrophage infiltration assay. Together, these findings revealed the underlying critical role of C1S in glioma tumorigenesis, progression, and the tumor immune microenvironment, contributing to further understanding of glioma pathogenesis and guiding immunotherapy.

Contrast-enhanced ultrasound can differentiate the level of glioma infiltration and correlate it with biological behavior: a study based on local pathology.

The objective of this study is to assess the diagnostic efficacy of contrast-enhanced ultrasound (CEUS) in determining the level of glioma infiltration and to investigate its correlation with pathological markers. A prospective study involving 16 adult glioma patients was conducted. Preoperative US-(Magnetic Resonance)MR fusion imaging was utilized for tumor infiltration localization, while CEUS was employed to assess hemodynamic alterations. Parameters such as peak intensity (PI), rise time (RT), time to peak (TTP), and area under the curve (AUC) were measured. Utilizing contralateral normal brain tissue as the reference standard. The Kruskal-Wallis H-test was conducted to compare CEUS and pathological parameters (significance level, p < 0.05; bonferroni correction) among tumor margins, infiltration zones, and normal tissues, as well as between low-grade glioma (LGG) and high-grade glioma (HGG) within the infiltration zone, based on whole slide pathological images analysis. Spearman correlation analysis was employed to determine the correlation coefficient between hemodynamics and pathology. Receiver operating characteristic (ROC) curves were drawn to evaluate the performance of CEUS in tumor classification. From tumor margin to normal tissue, PI, AUC, Ki67, EGFR, and 1p/19q showed a significant decreasing trend, while TTP, IDH-1, and MGMT gradually increased. RT was lower at the tumor margin but did not show statistically significant differences. In the infiltration zones, there was a significant increase in parameters such as PI, normalized PI (Nor_PI), AUC, and Ki67 from LGG to HGG, while RT, Nor_RT, TTP, Nor_TTP, IDH-1, and MGMT significantly decreased. Nor_AUC and EGFR increased but were not significant, and 1p/19q decreased but was not significant. RT and Nor_TTP were independent risk factors for distinguishing between LGG and HGG in the infiltration zone, with a combined diagnostic efficacy ROC of 0.891. The sensitivity reached 96.64% and the specificity reached 82.35%. There was a significant correlation between hemodynamic indicators and pathological indicators. CEUS can effectively differentiate levels of infiltration zones, which correlates with their biological behavior, with RT + Nor_TTP showing particularly highest diagnostic efficacy. These findings contribute to improving the accuracy of diagnosing infiltration zones and provide essential biological insights for subsequent treatments.

NCAPD3 is a prognostic biomarker and is correlated with immune infiltrates in glioma.

Non-SMC Condensin II Complex Subunit D3 (NCAPD3) has been linked with the genesis and progression of multiple human cancers. Nevertheless, the scientific value and molecular process of NCAPD3 in glioma remain unclear. We explored the level of NCAPD3 expression in pan-cancer by multiple online databases. And we focused on the level and prognostic value of NCAPD3 expression in glioma by immunohistochemistry (IHC) and survival analysis. Meanwhile, we verified the relationship between NCAPD3, biological function and immune infiltration in glioma by Linkedomics and SangerBox databases. The expression of NCAPD3 was increased in a variety of cancers, including glioma. Its high expression was strongly related to WHO grade (P=0.002) and programmed cell death ligand 1 (PD-L1) expression of glioma (P=0.001). Patients with a high level of NCAPD3 expression had a lower overall survival (OS) in glioma than patients with a low level of NCAPD3 expression. Multivariate statistical analyses showed NCAPD3 expression (P=0.040), WHO grade (P<0.001), 1p/19q codeletion (P<0.001), recurrence (P<0.001), age (P=0.023), and chemotherapy status (P=0.001) were meaningful independent prognostic factors in patients with glioma. Furthermore, bioinformatics analysis proved that NCAPD3 has been linked to immune infiltration in glioma. High level of NCAPD3 expression may serve as a promising prognostic biomarker and correlate with dendritic cell infiltration, representing a potential immunotherapy target in glioma.

Integrated analysis of bulk and single-cell RNA sequencing reveals the impact of nicotinamide and tryptophan metabolism on glioma prognosis and immunotherapy sensitivity

BackgroundNicotinamide and tryptophan metabolism play important roles in regulating tumor synthesis metabolism and signal transduction functions. However, their comprehensive impact on the prognosis and the tumor immune microenvironment of glioma is still unclear. The purpose of this study was to investigate the association of nicotinamide and tryptophan metabolism with prognosis and immune status of gliomas and to develop relevant models for predicting prognosis and sensitivity to immunotherapy in gliomas.MethodsBulk and single-cell transcriptome data from TCGA, CGGA and GSE159416 were obtained for this study. Gliomas were classified based on nicotinamide and tryptophan metabolism, and PPI network associated with differentially expressed genes was established. The core genes were identified and the risk model was established by machine learning techniques, including univariate Cox regression and LASSO regression. Then the risk model was validated with data from the CGGA. Finally, the effects of genes in the risk model on the biological behavior of gliomas were verified by in vitro experiments.ResultsThe high nicotinamide and tryptophan metabolism is associated with poor prognosis and high levels of immune cell infiltration in glioma. Seven of the core genes related to nicotinamide and tryptophan metabolism were used to construct a risk model, and the model has good predictive ability for prognosis, immune microenvironment, and response to immune checkpoint therapy of glioma. We also confirmed that high expression of TGFBI can lead to an increased level of migration, invasion, and EMT of glioma cells, and the aforementioned effect of TGFBI can be reduced by FAK inhibitor PF-573,228.ConclusionsOur study evaluated the effects of nicotinamide and tryptophan metabolism on the prognosis and tumor immune microenvironment of glioma, which can help predict the prognosis and sensitivity to immunotherapy of glioma.

Machine learning-based new classification for immune infiltration of gliomas.

Glioma is a highly heterogeneous and poorly immunogenic malignant tumor, with limited efficacy of immunotherapy. The characteristics of the immunosuppressive tumor microenvironment (TME) are one of the important factors hindering the effectiveness of immunotherapy. Therefore, this study aims to reveal the immune microenvironment (IME) characteristics of glioma and predict different immune subtypes using machine learning methods, providing guidance for immune therapy in glioma. We first performed unsupervised cluster analysis on the genes and arrays of 693 gliomas in CGGA database and 702 gliomas in TCGA database. Then establish and verify the classification model through Machine Learning (ML). Then, use DAVID to perform functional enrichment analysis for different immune subtypes. Next step, analyze the immune cell distribution, stemness maintenance, mesenchymal phenotype, neuronal phenotype, tumorigenic cytokines, molecular and clinical characteristics of different immune subtypes of gliomas. Firstly, we divide the IME of gliomas in the CGGA database into four different subtypes, namely IM1, IM2, IM3, and IM4; similarly, the IME of gliomas in the TCGA database can also be divided into four different subtypes (IMA, IMB, IMC, and IMD). Next, based on ML, we developed a highly reliable model for predicting different immune subtypes of glioma. Then, we found that Monocytic lineage, Myeloid dendritic cells, NK cells and CD8 T cells had the highest enrichment in the IM1/IMD subtypes. Cytotoxic lymphocytes were highest expressed in the IM4/IMA subtypes. Next step, Enrichment analysis revealed that the IM1-IMD subtypes were mainly closely related to the production and secretion of IL-8 and TNF signaling pathway. The IM2-IMB subtypes were strongly associated with leukocyte activation and NK cell mediated cytotoxicity. The IM3-IMC subtypes were closely related to mitotic nuclear division and mitotic cell cycle process. The IM4-IMA subtypes were strongly associated with Central Nervous System (CNS) development and striated muscle tissue development. Afterwards, Single sample gene set enrichment analysis (ssGSEA) showed that stemness maintenance phenotypes were mainly enriched in the IM4/IMA subtypes; Neuronal phenotypes were closely associated with the IM2/IMB subtypes; and mesenchymal phenotypes and tumorigenic cytokines were highly correlated with the IM2 /IMB subtypes. Finally, we found that compared with patients in the IM2/IMB and IM4/IMA subtypes, the IM1/IMD and IM3/IMC subtypes have the highest proportion of GBM patients, the shortest average overall survival of patients and the lowest proportion of patients with IDH mutation and 1p36/19q13 co-deletion. We developed a highly reliable model for predicting different immune subtypes of glioma by ML. Then, we comprehensively analyzed the immune infiltration, molecular and clinical features of different immune subtypes of gliomas and defined gliomas into four subtypes: immunogenic subtype, adaptive immune resistance subtype, mesenchymal subtype, and immune tolerance subtype, which represent different TMEs and different stages of tumor development.

Congress of Neurological Surgeons systematic review and evidence‑based guidelines on the management of recurrent diffuse low-grade glioma: update.

Target population These recommendations apply to adult patients with recurrent WHO grade 2 infiltrative diffuse glioma (oligodendroglioma, astrocytoma).Questions and Recommendations:Imaging Q1: In adult patients with suspected recurrence of histologically proven WHO grade 2 diffuse glioma, do advanced imaging techniques using magnetic resonance spectroscopy, perfusion weighted imaging, diffusion weighted imaging or PET provide superior assessment of tumor recurrence and histologic progression compared to standard MRI neuroimaging?Recommendation Level III: In adult patients with suspected recurrence of histologically proven WHO grade 2 diffuse glioma, advanced imaging techniques using magnetic resonance spectroscopy, perfusion weighted imaging, diffusion weighted imaging or PET are suggested for identification of tumor recurrence or histologic progression.Pathology Q1: In adult patients with suspected recurrence of histologically proven WHO grade 2 diffuse glioma, is molecular testing for IDH-1, IDH-2, and TP53 Mutations and MGMT promotor methylation mutation warranted for predicting survival and formulating treatment recommendations?Recommendation Level III: It is suggested that IDH mutation status be determined for diagnostic purposes. TP53 mutations occur early in WHO grade 2 diffuse glioma pathogenesis, remain stable, and are not suggested as a marker of predisposition to malignant transformation at recurrence or other measures of prognosis. Assessment of MGMT status is suggested as an adjunct to assessing prognosis. Assessment of CDK2NA status is suggested since this is associated with malignant progression of WHO grade 2 diffuse gliomas.Q2: In adult patients with suspected recurrence of histologically proven WHO Grade 2 diffuse glioma, is testing of proliferation indices (MIB-1 and/or BUdR) warranted for predicting survival and formulating treatment recommendations?Recommendation Level III: It is suggested that proliferative indices (MIB-1 or BUdR) be measured in WHO grade 2 diffuse glioma as higher proliferation indices are associated with increased likelihood of recurrence and shorter progression free and overall survival.Chemotherapy Q1: In adult patients with suspected recurrence of histologically proven WHO grade 2 diffuse glioma, does addition of temozolomide (TMZ), other cytotoxic agents or targeted agents to their treatment regimen improve PFS and/or OS?Recommendation Level III: Temozolomide is suggested in the therapy of recurrent WHO grade 2 diffuse glioma as it may improve clinical symptoms. PCV is suggested in the therapy of WHO grade 2 diffuse glioma at recurrence as it may improve clinical symptoms with the strongest evidence being for oligodendrogliomas. TMZ is suggested as the initial choice for recurrent WHO grade 2 diffuse glioma. Carboplatin is not suggested as there is no significant benefit from carboplatin as single agent therapy for recurrent WHO grade 2 diffuse gliomas. There is insufficient evidence to make any recommendations regarding other agents in the management of recurrent WHO grade 2 diffuse glioma.Radiotherapy Q1: In adult patients with suspected recurrence of histologically proven WHO grade 2 diffuse glioma, does addition of radiotherapy to treatment regimen improve PFS and/or OS?Recommendation Level III: Radiation is suggested at recurrence if there was no previous radiation treatment. Q2: In adult patients with suspected recurrence of histologically proven WHO grade 2 diffuse glioma after previous radiotherapy, does addition of re-irradiation or proton therapy to the treatment regimen improve PFS and/or OS?Recommendation Level III: It is suggested that re-irradiation be considered in the setting of WHO grade 2 diffuse glioma recurrence as it may provide benefit in PFS and OS.Surgery Q1: In adult patients with suspected recurrence of histologically proven WHO grade 2 diffuse glioma, does surgical resection improve PFS and/or OS?. There is insufficient evidence to make any new specific recommendations regarding the value of surgery or extent of resection in relationship to survival for recurrent WHO grade 2 diffuse glioma.

Mitogen-activated protein kinase kinase kinase 1 facilitates the temozolomide resistance and migration of GBM via the MEK/ERK signalling.

Mitogen-Activated Protein Kinase Kinase Kinase 1 (MAP3K1) is overexpressed in gliomas; however, its clinical significance, biological functions, and underlying molecular mechanisms remain unclear. Abnormal overexpression of MAP3K1 in glioma is strongly associated with unfavourable clinicopathological characteristics and disease progression. MAP3K1 could potentially serve as a reliable diagnostic and prognostic biomarker for glioma. MAP3K1 silencing suppressed the migration but had no effect on the proliferation and cell death of Glioblastoma Multiforme (GBM) cells. MAP3K1 knockdown exacerbated the temozolomide (TMZ) induced inhibition of glioma cell proliferation and death of GBM cells. In addition, MAP3K1 knockdown combined with TMZ treatment significantly inhibited the growth and increased cell death in organoids derived from GBM patients. MAP3K1 knockdown reversed TMZ resistance of GBM in intracranial glioma model. In terms of molecular mechanisms, the phosphorylation level of ERK was significantly decreased by MAP3K1 silencing. No significant change in the JNK pathway was found in MAP3K1-silenced GBM cells. Inhibition of ERK phosphorylation suppressed the migration and enhanced the TMZ sensibility of GBM cells. MAP3K1 was correlated with the immune infiltration in glioma. MAP3K1 could facilitate the migration and TMZ resistance of GBM cells through MEK/ERK signalling.

Proapoptotic and antimigration properties of osthole in combination with LY294002 against human glioma cells.

Anaplastic astrocytoma and glioblastoma multiforme are infiltrating and vascularized gliomas with a high degree of chemoresistance and metastasis. Our previous studies have shown that osthole may be of great importance in the treatment of gliomas. Therefore, in this work, for the first time, coumarin was used in combination with LY294002-an inhibitor of the PI3K-Akt/PKB-mTOR pathway, which is overly active in gliomas. MOGGCCM and T98G cells were incubated with osthole and LY294002, alone and in combination. Staining with specific fluorochromes was used to visualize cell death and the scratch test to assess the migration. The level of proteins was estimated by immunoblotting. Forming protrusions were visualized by SEM, and immunocytochemistry was used to determine the localization of proteins. Additionally, the expression of Bcl-2, beclin 1 and Raf kinase was silenced using specific siRNA. The obtained results showed that osthole in combination with LY294092 effectively inhibited the migration of glioma cells by reducing the level of metaloproteinases and Rho family proteins, as well as decreasing the level of N-cadherin. In addition, the combination of compounds induced apoptosis. New combination of compounds shows a high pro-apoptotic potential and also inhibits the migration of gliomas cells.

Emerging Role of the Slit/Roundabout (Robo) Signaling Pathway in Glioma Pathogenesis and Potential Therapeutic Options

Gliomas represent the most common primary Central Nervous System (CNS) tumors, characterized by increased heterogeneity, dysregulated intracellular signaling, extremely invasive properties, and a dismal prognosis. They are generally resistant to existing therapies and only a few molecular targeting options are currently available. In search of signal transduction pathways with a potential impact in glioma growth and immunotherapy, the Slit guidance ligands (Slits) and their Roundabout (Robo) family of receptors have been revealed as key regulators of tumor cells and their microenvironment. Recent evidence indicates the implication of the Slit/Robo signaling pathway in inflammation, cell migration, angiogenesis, and immune cell infiltration of gliomas, suppressing or promoting the expression of pivotal proteins, such as cell adhesion molecules, matrix metalloproteinases, interleukins, angiogenic growth factors, and immune checkpoints. Herein, we discuss recent data on the significant implication of the Slit/Robo signaling pathway in glioma pathology along with the respective targeting options, including immunotherapy, monoclonal antibody therapy, and protein expression modifiers.

Somatosensory Mapping Using a Novel Sensory Discrimination Task: Technical Note.

Although diffuse gliomas in the primary somatosensory cortex (S1) are often considered resectable, gliomas in the primary motor cortex require motor mapping to preserve motor function. Recent evidence indicates that some somatosensory cortex neurons may trigger motor responses, necessitating refined somatosensory mapping techniques. Using piezoelectric tactile stimulators on patients' faces and hands, we delivered 25 Hz vibrations and prompted patients to discriminate between dermatomes. Testing included areas contralateral to tumor-infiltrated and to non-tumor-infiltrated cortical regions. Sensory thresholds were determined by reducing stimulus intensity based on performance. Intraoperatively, electrocorticography electrode arrays were used to map sensory responses, and postoperative assessments evaluated sensory outcomes. The high-grade glioma case involved a 61-year-old man with right-sided weakness and numbness with a left parietal mass on MRI. Preoperative testing showed that the average vibratory detection threshold of the hand contralateral to the suspected tumor site was significantly higher than that of the hand contralateral to healthy cortex (P < .001). Intraoperative mapping confirmed the absence of functional involvement in cortical structures overlying the tumor. Postoperative imaging confirmed gross total resection, and sensory vibratory thresholds were normalized (P = .51). The low-grade glioma case included a 54-year-old man with a left parietal nonenhancing mass on MRI. No baseline sensory impairments were found on preoperative testing. Intraoperative mapping identified motor and sensory cortices, guiding tumor resection while preserving motor function. Postoperative MRI confirmed near-total resection, but new sensory impairments were noted in the hand and face contralateral to the resection site (P < .001). These deficits resolved by postoperative day 11, with no evidence of tumor progression on follow-up imaging. The sensory discrimination task provides a quantifiable method for assessing sensory changes and functional outcomes related to glioma. This technique enhances our understanding of how glioma infiltration remodels sensory systems and affects clinical outcomes in patients.

Immune landscape of oncohistone-mutant gliomas reveals diverse myeloid populations and tumor-promoting function

Histone H3-mutant gliomas are deadly brain tumors characterized by a dysregulated epigenome and stalled differentiation. In contrast to the extensive datasets available on tumor cells, limited information exists on their tumor microenvironment (TME), particularly the immune infiltrate. Here, we characterize the immune TME of H3.3K27M and G34R/V-mutant gliomas, and multiple H3.3K27M mouse models, using transcriptomic, proteomic and spatial single-cell approaches. Resolution of immune lineages indicates high infiltration of H3-mutant gliomas with diverse myeloid populations, high-level expression of immune checkpoint markers, and scarce lymphoid cells, findings uniformly reproduced in all H3.3K27M mouse models tested. We show these myeloid populations communicate with H3-mutant cells, mediating immunosuppression and sustaining tumor formation and maintenance. Dual inhibition of myeloid cells and immune checkpoint pathways show significant therapeutic benefits in pre-clinical syngeneic mouse models. Our findings provide a valuable characterization of the TME of oncohistone-mutant gliomas, and insight into the means for modulating the myeloid infiltrate for the benefit of patients.