Pathogenesis Of GBM Research Articles

Artificial Intelligence and Omics in Malignant Gliomas.

The availability of large scale multi-omics data requires development of computational models to infer valuable biological insights for the implementation of precision medicine. Artificial intelligence (AI) refers to a host of computational algorithms that is becoming a major tool capable of integrating large genomic, transcriptomic, proteomic, and metabolomic data. Machine learning (ML) is the most significant AI algorithm in health sciences have exploded, specifically due to the recent progress made by deep learning. Although the use of AI/ML tools in GBM-omics is still at an early stage, a comprehensive discussion of how AI can be used to unravel various aspects of GBM (intratumor heterogeneity, biomarker discovery, survival prediction, and treatment optimization) would be highly relevant to both researchers and clinicians. Here, we aim to review the different AI-based techniques that have been used to study GBM pathogenesis using multi-omics data over the last decade. We first summarize different types of GBM related omics resources that can be used to develop AI models. We then discuss various AI applications for multi-omics data in order to enhance GBM precision medicine. Finally, we discuss the technical and ethical challenges that limit its application and ways to improve its implementation in clinics.

Unveiling the impact of SUMOylation at K298 site of heat shock factor 1 on glioblastoma malignant progression

BackgroundGlioblastoma (GBM) poses a significant medical challenge due to its aggressive nature and poor prognosis. Mitochondrial unfolded protein response (UPRmt) and the heat shock factor 1 (HSF1) pathway play crucial roles in GBM pathogenesis. Post-translational modifications, such as SUMOylation, regulate the mechanism of action of HSF1 and may influence the progression of GBM. Understanding the interplay between SUMOylation-modified HSF1 and GBM pathophysiology is essential for developing targeted therapies. MethodsWe conducted a comprehensive investigation using cellular, molecular, and in vivo techniques. Cell culture experiments involved establishing stable cell lines, protein extraction, Western blotting, co-immunoprecipitation, and immunofluorescence analysis. Mass spectrometry was utilized for protein interaction studies. Computational modeling techniques were employed for protein structure analysis. Plasmid construction and lentiviral transfection facilitated the manipulation of HSF1 SUMOylation. In vivo studies employed xenograft models for tumor growth assessment. ResultsOur research findings indicate that HSF1 primarily undergoes SUMOylation at the lysine residue K298, enhancing its nuclear translocation, stability, and downstream heat shock protein expression, while having no effect on its trimer conformation. SUMOylated HSF1 promoted the UPRmt pathway, leading to increased GBM cell proliferation, migration, invasion, and reduced apoptosis. In vivo studies have confirmed that SUMOylation of HSF1 enhances its oncogenic effect in promoting tumor growth in GBM xenograft models. ConclusionThis study elucidates the significance of SUMOylation modification of HSF1 in driving GBM progression. Targeting SUMOylated HSF1 may offer a novel therapeutic approach for GBM treatment. Further investigation into the specific molecular mechanisms influenced by SUMOylated HSF1 is warranted for the development of effective targeted therapies to improve outcomes for GBM patients.

The causal relationship between CSF metabolites and GBM: a two-sample mendelian randomization analysis

BackgroundGlioblastoma multiforme (GBM) is a highly aggressive primary malignant brain tumor characterized by rapid progression, poor prognosis, and high mortality rates. Understanding the relationship between cerebrospinal fluid (CSF) metabolites and GBM is crucial for identifying potential biomarkers and pathways involved in the pathogenesis of this devastating disease.MethodsIn this study, Mendelian randomization (MR) analysis was employed to investigate the causal relationship between 338 CSF metabolites and GBM. The data for metabolites were obtained from a genome-wide association study summary dataset based on 291 individuals, and the GBM data was derived from FinnGen included 91 cases and 174,006 controls of European descent. The Inverse Variance Weighted method was utilized to estimate the causal effects. Supplementary comprehensive assessments of causal effects between CSF metabolites and GBM were conducted using MR-Egger regression, Weighted Median, Simple Mode, and Weighted Mode methods. Additionally, tests for heterogeneity and pleiotropy were performed.ResultsThrough MR analysis, a total of 12 identified metabolites and 2 with unknown chemical properties were found to have a causal relationship with GBM. 1-palmitoyl-2-stearoyl-gpc (16:0/18:0), 7-alpha-hydroxy-3-oxo-4-cholestenoate, Alpha-tocopherol, Behenoyl sphingomyelin (d18:1/22:0), Cysteinylglycine, Maleate, Uracil, Valine, X-12,101, X-12,104 and Butyrate (4:0) are associated with an increased risk of GBM. N1-methylinosine, Stachydrine and Succinylcarnitine (c4-dc) are associated with decreased GBM risk.ConclusionIn conclusion, this study sheds light on the intricate interplay between CSF metabolites and GBM, offering novel perspectives on disease mechanisms and potential treatment avenues. By elucidating the role of CSF metabolites in GBM pathogenesis, this research contributes to the advancement of diagnostic capabilities and targeted therapeutic interventions for this aggressive brain tumor. Further exploration of these findings may lead to improved management strategies and better outcomes for patients with GBM.

DNAJC1 facilitates glioblastoma progression by promoting extracellular matrix reorganization and macrophage infiltration

BackgroundGlioblastoma (GBM) is a high-grade and heterogeneous subtype of glioma that presents a substantial challenge to human health, characterized by a poor prognosis and low survival rates. Despite its known involvement in regulating leukemia and melanoma, the function and mechanism of DNAJC1 in GBM remain poorly understood.MethodsUtilizing data from the TCGA, CGGA, and GEO databases, we investigated the expression pattern of DNAJC1 and its correlation with clinical characteristics in GBM specimens. Loss-of-function experiments were conducted to explore the impact of DNAJC1 on GBM cell lines, with co-culture experiments assessing macrophage infiltration and functional marker expression.ResultsOur analysis demonstrated frequent overexpression of DNAJC1 in GBM, significantly associated with various clinical characteristics including WHO grade, IDH status, chromosome 1p/19q codeletion, and histological type. Moreover, Kaplan‒Meier and ROC analyses revealed DNAJC1 as a negative prognostic predictor and a promising diagnostic biomarker for GBM patients. Functional studies indicated that silencing DNAJC1 impeded cell proliferation and migration, induced cell cycle arrest, and enhanced apoptosis. Mechanistically, DNAJC1 was implicated in stimulating extracellular matrix reorganization, triggering the epithelial-mesenchymal transition (EMT) process, and initiating immunosuppressive macrophage infiltration.ConclusionsOur findings underscore the pivotal role of DNAJC1 in GBM pathogenesis, suggesting its potential as a diagnostic and therapeutic target for this challenging disease.

CircZNF609 and circNFIX as possible regulators of glioblastoma pathogenesis via miR-145-5p/EGFR axis

Glioblastoma is a rare and deadly malignancy with a low survival rate. Emerging evidence has shown that aberrantly expressed circular RNAs (circRNAs) play a critical role in the initiation and progression of GBM tumorigenesis. The oncogenic function of circZNF609 and circNFIX is involved in several types of cancer, but the role and underlying mechanism of these circRNAs in glioblastoma remain unclear. In this study, we hypothesized that circZNF609 and circNFIX may regulate EGFR through sponging miR-145-5p. Herein, we assessed the expression levels of circZNF609, circNFIX, miR-145-5p, and EGFR using quantitative polymerase chain reaction in glioblastoma patients and normal brain samples. The results showed that circZNF609, circNFIX, and EGFR expression levels were upregulated and miR145-5p was downregulated (p = 0.001, 0.06, 0.002, and 0.0065, respectively), while there was no significant association between clinicopathological features of the patients and the level of these genes expression. We also found a significant inverse correlation between miR145-5p and the expression of cZNF609, cNFIX and EGFR (p = 0.0003, 0.0006, and 0.009, respectively). These findings may open a new window for researchers to better understand the potential pathways involved in GBM pathogenesis. In conclusion, it may provide a new potential pathway for the development of effective drugs for the treatment of GBM patients.

Influence of SLC40A1 on Cytokine Interactions and Immune Infiltration in Glioblastoma.

Numerous studies have explored the various functions of Slc40a1 in cancer development. However, the role of Slc40a1 in primary glioblastoma requires further investigation. Initially, we observed that GBM patients with high Slc40a1 expression had a more favorable prognosis than those with low Slc40a1 expression, as evidenced by an analysis of the TIMER database. Subsequent analysis using the cancer genome atlas (TCGA) database enabled us to identify potential underlying mechanisms involved. Further analyses, including GO, KEGG, GSEA, immune infiltration, and correlation analyses, revealed that Slc40a1 primarily affected cytokine interactions, particularly with Ccl14 and Il18, resulting in changes in the immune microenvironment and ultimately leading to a better prognosis in GBM patients. We validated our findings by examining a tissue microarray with 180 samples and confirmed that GBM patients with high SLC40A1 protein expression exhibited more favorable prognostic outcomes than those with low SLC40A1 protein expression. Immunofluorescence analysis also revealed a significant correlation between SLC40A1 protein expression and the protein expression of IL18 and CCL14. These findings suggest that Slc40a1 may play a role in GBM pathogenesis by modulating the tumor immune microenvironment through the regulation of Il18 and Ccl14. Hence, targeting Slc40a1 might offer potential benefits for immunotherapeutic interventions and prognostic assessments in GBM patients.

Abstract LT05: METTL8-MEDIATED EPITRANSCRIPTOMIC REGULATION OF GBM CYCLING STATE IS DEPENDENT ON RTK/PI3K/AKT SIGNALING

Abstract Glioblastoma (GBM) is a lethal brain tumor with limited treatment options. Treatment failures are often attributed to the existence of glioma stem cells (GSCs), which confer intratumoral heterogeneity and therapy resistance. Contrary to common belief that cancer cells employ aerobic glycolysis (Warburg effect) to sustain their metabolic requirements, GSCs rely on oxidative phosphorylation (OXPHOS) for energy production. As a result, GSCs are uniquely sensitive to OXPHOS inhibitors (Gboxin), as well as mitochondrial translation inhibitors which disrupt OXPHOS. METTL8 is a newly discovered mitochondrial methyltransferase which catalyzes m3C32 modifications in mitochondrial tRNAsThr/Ser(UCN) (mt-tRNAs). This post-transcriptional modification ensures the optimal structure of mt-tRNAs to facilitate efficient translation of mitochondrial proteins involved in electron transport chain (ETC). Although the epitranscriptomic functions of METTL8 have been well characterized, its roles in cancers (i.e. glioblastoma) remain largely unexplored. In this study, we showed that METTL8 is overexpressed in GBM and high METTL8 expression portends poor patient prognosis. In GSC, METTL8 is under the transcriptional regulation of HIF-1α, and the chromatin accessibility at METTL8 promoter is facilitated by the deposition of histone variant H2AZ. METTL8 depletion downregulated m3C32 modifications in mt-tRNAsThr/Ser(UCN) in GSC, leading to impaired mitochondrial translation and OXPHOS defects. Phenotypically, METTL8 knockdown (KD) compromised GSCs’ self-renewal, proliferation, invasiveness and tumorigenicity. Interestingly, METTL8-KD GSC acquired a slow cycling state which is linked to reduced receptor tyrosine kinase (RTK) signaling. Consistently, METTL8-KD GSC showed lower Akt phosphorylation and exhibited increased sensitivity to mTOR/Akt inhibitors. Finally, our mechanistic findings led to the identification of a novel HIF1-α/Akt inhibitor drug combination which faithfully recapitulates the phenotypes of METTL8-KD GSCs. In conclusion, our findings provide the first in-depth study of METTL8 roles in GBM pathogenesis, and highlights a novel drug combination which could potentially be used to treat this dreadful disease. Citation Format: Bernice Woon Li Lee, You Heng Chuah, Jeehyun Yoon, Oleg V. Grinchuk, Jia Feng, Yajing Liang, Jayshree L Hirpara, Ya Ting Shen, Loo Chien Wang, Yan Ting Lim, Tianyun Zhao, Radoslaw M Sobota, Tan Boon Toh, Shazib Pervaiz, Zhewang Lin, Derrick Sek Tong Ong. METTL8-MEDIATED EPITRANSCRIPTOMIC REGULATION OF GBM CYCLING STATE IS DEPENDENT ON RTK/PI3K/AKT SIGNALING [abstract]. In: Proceedings of Frontiers in Cancer Science; 2023 Nov 6-8; Singapore. Philadelphia (PA): AACR; Cancer Res 2024;84(8_Suppl):Abstract nr LT05.

Abstract 6248: Multilayered molecular interactions underlying glioblastoma pathogenesis through multi-omics analysis

Abstract Glioblastoma, IDH-wild type (GBM) is the most common malignant and treatment-refractory brain tumor with a dismal prognosis. Despite the identification of various driver genes in previous large-scale genomic analyses, there has been limited progress in the development of novel treatments. Acquiring an extensive understanding of the molecular mechanisms underlying GBM pathogenesis is crucial to improve prognostic outcomes. We analyzed 289 whole-genome sequencing data (WGS) including 159 unpublished deep WGS (≥ ×120 coverage) along with RNA-seq, DNA methylation array, and assay for transposase-accessible chromatin with sequencing (ATAC-seq) to uncover the molecular mechanisms regulating development and progression of GBM. Our deep WGS enables us to delineate a fine view of clonal architecture, where mutational signature varies between clonal and subclonal mutations, suggesting that different mutational processes contribute to GBM pathogenesis depending on its developmental stage. The differentiation status of tumor cells detected by transcriptional deconvolution analysis is associated with multi-layer profiles including genomic alterations, expression subtypes, DNA methylation, and open chromatin status. Tumors predominantly comprised of differentiated cells display genetic and epigenetic profiles that align with the classical subtype, whereas tumors predominantly composed of stem-like cells exhibit profiles consistent with the proneural subtype. ATAC-seq unveils genome-wide chromatin accessibility features associated with gene expression subtypes. Motif enrichment analysis of differentially accessible sites among the subtypes identified specific transcription factors. The proneural subtype is enriched for the SOX10 binding motif, which is associated with regulating cell states, and exhibits higher expression of SOX10 compared to other subtypes. Conversely, the mesenchymal and classical subtypes are enriched for the CREB1 binding motif, which promotes cell proliferation and angiogenesis through TGFβ2 upregulation, wherein TGFβ2 expression is significantly elevated. These findings support a model in which the difference in chromatin structure also regulates the progression of GBM.Our analysis reveals the multi-layer molecular interactions underlying the progression of GBM enhancing our understanding of the pathogenesis. Citation Format: Takuma Nakashima, Yusuke Funakoshi, Ryo Yamamoto, Yuriko Sugihara, Shohei Nambu, Yoshiki Arakawa, Shota Tanaka, Joji Ishida, Ryuta Saito, Ryosuke Hanaya, Koji Yoshimoto, Yoshitaka Narita, Hiromichi Suzuki. Multilayered molecular interactions underlying glioblastoma pathogenesis through multi-omics analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6248.

The hidden architects of glioblastoma multiforme: Glioma stem cells

AbstractGlioblastoma multiforme (GBM), a WHO grade IV diffuse glioma, is a highly aggressive brain tumor with a median survival of less than a year. Characterized by robust proliferation and invasion, recent studies spotlight glioma stem cells (GSCs) within GBM tumors, pivotal in tumor development, progression, and treatment resistance. This review aims to shed light on the critical role of GSCs in the initiation and progression of GBM, emphasizing their contribution to tumor development and resistance to existing treatments. Unlike normal stem cells, GSCs play a pivotal role in GBM pathogenesis. The review delves into the unique characteristics of GSCs, marked by heightened metabolic activities and distinct epigenetic and transcriptional programming. Recognizing the significance of GSCs in recent years, the review examines how their presence amplifies the lethal nature of GBM. The review also critically evaluates recent advancements in glioma and GBM diagnostic methods and treatment therapies, which also include targeting GSCs. Providing a concise yet comprehensive overview, the review contributes insights into GBM's intricate dynamics, offering potential directions for future research and therapeutic strategies.

10064-GGE-6 A MULTI-OMIC LANDSCAPE OF GLIOBLASTOMA, IDH-WILD TYPE

Abstract Glioblastoma (GBM) is the most common and highly resistant malignant brain tumor. Although the previous large-scale genomic analyses identified numerous driver genes, limited progress has been achieved in the development of novel treatments. To obtain further insights into the molecular mechanisms underlying the development of GBM, an integrated analysis including epigenetic and transcriptomic analyses, known to regulate malignant tumor progression, is imperative. We analyzed 289 whole-genome sequencing (WGS) including 159 unpublished deep WGS (≥ ×120 coverage) along with RNA-seq, DNA methylation array, whole-genome bisulfite sequencing, and assay for transposase-accessible chromatin with sequencing (ATAC-seq).Mutational analysis identified known driver alterations exhibiting inter-tumoral heterogeneity. Deep WGS enables us to delineate a fine view of clonal architecture demonstrating distinct mutational signatures between clonal and subclonal mutations, suggesting different mutational processes contribute to GBM pathogenesis depending on the developmental stage. Genetic alterations are strongly associated with gene expression subtypes and DNA methylation patterns. Transcriptional deconvolution analysis reveals the heterogeneous proportion of differentiated and stem-like cell states among cases. Tumors predominantly comprised of differentiated cells display genetic and epigenetic profiles that align with the classical subtype, whereas tumors predominantly composed of stem-like cells exhibit profiles consistent with the proneural subtype. Genome-wide chromatin accessibility patterns are well associated with expression subtypes of GBM. Motif enrichment analysis of open chromatin sites identified specific transcription factor binding sites, such as the SOX10 motif in the proneural subtype, known to regulate cell states, and the CREB motif in the mesenchymal and classical subtypes, which promote cell proliferation and angiogenesis through TGF-beta regulation. These findings support a model in which the difference in chromatin structure also regulates the progression of GBM.Our analysis encompassing multilayer molecular mechanisms reveals that GBM evolves through harboring genetic alterations and epigenetic modifications depending on the tumor initiation stage and cellular differentiation status.

EPCO-32. DISSECTING THE INTRA- AND INTER-TUMORAL HETEROGENEITY UNDERLYING GLIOBLASTOMA PATHOGENESIS UTILIZING MULTI-OMICS ANALYSIS

Abstract Glioblastoma (GBM) is the most common malignant brain tumor with a dismal prognosis. Considering its extensive molecular diversity underlies therapeutic resistance to multimodal treatment, it is imperative to reveal intra- and inter-tumoral heterogeneity, leading to further understanding of GBM pathogenesis. We analyzed 289 whole-genome sequencing data (WGS) including 159 unpublished deep WGS (≥ ×120 coverage) along with RNA-seq, DNA methylation array, whole-genome bisulfite sequencing, and assay for transposase-accessible chromatin with sequencing (ATAC-seq) to uncover the multi-omics molecular heterogeneity of GBM. Along with inter-tumoral heterogeneity of genetic driver alterations, deep WGS enables us to delineate a fine view of clonal architecture where mutational signatures differ across clonal and subclonal mutations, supporting that different mutational processes contribute to GBM pathogenesis depending on the developmental stage. As well, tumor cell differentiation status detected by transcriptional deconvolution analysis is associated with multi-layer profiles including genome, transcriptome, epigenome, and chromatin status. ATAC-seq demonstrated distinct features of genome-wide chromatin accessibility associated with gene expression subtypes of GBM. Motif enrichment analysis detects the differentially accessible regions where the proneural subtypes are enriched with the SOX10 motif, known as a transcription factor for mesenchymal transition whereas the mesenchymal and classical subtypes are enriched with the CREB/ATF motif, a regulator of TGF beta associated with a poor prognosis. Our findings support a model in which GBM evolves through generating genetic and epigenetic intra-tumoral heterogeneity suggesting that specific cell states may have distinct vulnerability to mutational processes and epigenetic modifications. Our analysis reveals the molecular mechanisms underlying the progression of GBM enhancing our understanding of the pathogenesis.

PLEKHA4 promotes glioblastoma progression through apoptosis inhibition, tumor cell migration, and macrophage infiltration

BackgroundGlioblastoma(GBM) has a profound impact on human health, making the identification of reliable prognostic biomarkers pivotal. While PLEKHA4 has been associated with tumor genesis and development, its role in gliomas is still uncertain. MethodsWe analyzed PLEKHA4 expression in tumor tissues using the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Additionally, we utilized TCGA data to investigate its impact on prognosis, pathway enrichment, and immune infiltration. In vitro loss-of-function experiments were conducted to elucidate the effect of PLEKHA4 silencing on GBM cell behavior. ResultsTCGA and GEO data sets revealed increased levels of PLEKHA4 expression in glioma tissues. Furthermore, we identified a correlation between PLEKHA4 expression and higher disease classification, pathological grading, and poorer prognosis. Silencing PLEKHA4 in vitro resulted in decreased glioma cell migration and increased apoptosis. It also reduced macrophage infiltration and hindered M2 polarization of macrophages. ConclusionOur findings highlight the pivotal role of PLEKHA4 in GBM pathogenesis and suggest its potential as a diagnostic and therapeutic target for GBM.

The identification of key genes and pathways in glioblastoma by bioinformatics analysis

ABSTRACT GBM is the most common and aggressive type of brain tumor. It is classified as a grade IV tumor by the WHO, the highest grade. Prognosis is generally poor, with most patients surviving only about a year. Only 5% of patients survive longer than 5 years. Understanding the molecular mechanisms that drive GBM progression is critical for developing better diagnostic and treatment strategies. Identifying key genes involved in GBM pathogenesis is essential to fully understand the disease and develop targeted therapies. In this study two datasets, GSE108474 and GSE50161, were obtained from the Gene Expression Omnibus (GEO) to compare gene expression between GBM and normal samples. Differentially expressed genes (DEGs) were identified and analyzed. To construct a protein-protein interaction (PPI) network of the commonly up-regulated and down-regulated genes, the STRING 11.5 and Cytoscape 3.9.1 were utilized. Key genes were identified through this network analysis. The GEPIA database was used to confirm the expression levels of these key genes and their association with survival. Functional and pathway enrichment analyses on the DEGs were conducted using the Enrichr server. In total, 698 DEGs were identified, consisting of 377 up-regulated genes and 318 down-regulated genes. Within the PPI network, 11 key up-regulated genes and 13 key down-regulated genes associated with GBM were identified. NOTCH1, TOP2A, CD44, PTPRC, CDK4, HNRNPU, and PDGFRA were found to be important targets for potential drug design against GBM. Additionally, functional enrichment analysis revealed the significant impact of Epstein-Barr virus (EBV), Cell Cycle, and P53 signaling pathways on GBM.

Investigation of leptomeningeal disease in high grade glioma and characterization of molecular alterations.

2070 Background: Leptomeningeal disease (LMD) is a challenging complication of high grade glioma (HGG) and questions remain regarding risk factors, molecular associations, and optimal treatment. Here we report updated results on a larger cohort from our previously reported multicenter study (Shoaf 2022, Neuro-Oncology). Methods: Patients with molecularly-profiled HGG (Caris Life Sciences; Phoenix, AZ) with LMD at 3 institutions were included. NextGen Sequencing of DNA (592 gene or whole exome) and RNA (whole transcriptome) were tested. Medical records were reviewed for clinicopathologic characteristics and outcome. Kaplan-Meier estimates of survival were performed using Cox’s proportional hazard model. Mann-Whitney U or Chi-square tests were applied for molecular comparison as appropriate and adjusted for multiple comparisons. Results: Seventy-two patients (female: 20, male: 52; median age: 54.5y) were identified, comprising 65 grade 4 tumors (glioblastoma [GBM]: 62; gliosarcoma: 2; H3K27M diffuse midline glioma: 1), 5 grade 3 tumors (astrocytoma: 4; pleomorphic xanthoastrocytoma: 1), and 1 astrocytoma NOS. LMD diagnosed at glioma diagnosis (n=23) vs. recurrence (n=44) was associated with longer post-LMD survival [pLMD-OS: 16.9m vs. 5.5m, p<0.0001] but similar overall survival [mOS: 16.9m vs. 20.9m; p=0.36]. Pathology-diagnosed LMD (n=15) vs. MRI-diagnosed LMD (n=54) was associated with longer post-LMD survival [pLMD-OS: 15.2m vs. 6.2m, p=0.0002] but similar overall survival [mOS: 16.9m vs. 20.9m; p=0.72]. Post-LMD survival [pLMD-OS: 8.7m vs. 6.8m, p=0.33] and overall survival [mOS: 21.1m vs. 20.9m, p=0.20] were similar for supratentorial (n=45) vs. infratentorial/spinal (n=10) locations, and post-LMD survival did not significantly differ for symptomatic (n=40) vs. asymptomatic (n=22) patients [pLMD-OS: 6.6m vs. 10.5m, p=0.13). pTERT mutation (73%), MGMT methylation (38%), EGFR amplification (31%), and PTEN mutation (28%) were the most prevalent molecular alterations in this group. Comparison of grade 4 LMD tumors with an independent GBM cohort (n=5431) suggested a male predominance (73.4% vs. 58.5%, p=0.016) and a trend towards more frequent mutations in RB1 (25% vs. 9.2%, p=0.002) and MDM4 (12.7% vs. 4.3%, p=0.01) and amplification of WIF1 (6.1% vs. 0.3%, p=0.006), CHIC2 (17.0% vs. 5.2%, p=0.002), and LGR5 (5.9% vs. 0.4%, p=0.012). The expression of immune checkpoint-related genes was similar, although a trend towards immunologically “colder” tumors in the LMD cohort was observed. However, these effects were not significant after correcting for multiple comparisons. Conclusions: LMD is more common in male patients and may be associated with various genomic alterations and tumor microenvironment differences. Overall survival does not differ from patients without LMD, but these differences may provide clues to the pathogenesis and treatment resistance of GBM.

Association of Traumatic Brain Injury and Glioblastoma Multiforme: A Case Series.

Glioblastoma multiforme (GBM) is an aggressive variant of central nervous system gliomas that carries a dismal prognosis. Although GBM is the most frequently occurring and malignant type of glioma accounting for more than 60% of all brain tumors in adults, its overall incidence is rare, occurring at a rate of 3.21 per 100,000 persons. Little is known about the etiology of GBM, but one proposed theory is that GBM pathogenesis may be linked to a chronic inflammatory course initiated by traumatic injury to the brain. Limited case reports have suggested an association between GBMs and traumatic brain injury (TBI), but larger case-control and epidemiologic studies have been inconclusive. We present three service members (two active duty and one retired) who developed GBM near the original site of prior head trauma. Each service member's military occupation was in the special operations community and shared a common theme of TBI following head trauma/injury. The current research on the association between TBI and GBM is limited and conflicting, predominantly due to the low incidence of the disease in the general population. Evidence has indicated that TBI should be considered a chronic disease with long-term health impacts, including long-term disability, dementia, epilepsy, mental health conditions, and cardiovascular diseases. With the addition of our patients, as well as a recently published study proposing a molecular association between trauma and GBM, further research is needed to better understand the potential relationship.

Abstract 4869: Furin and Notch signaling pathway as part of the 2OHOA landscape against glioblastoma

Abstract Glioblastoma (GBM) is the most common and aggressive cancer tumor of the central nervous system, with only 12-15 months of patients’ median survival. Melitherapy is a novel therapeutic platform based on the regulation of the membrane’s structure and organization with the consequent modulation of certain cell signals. In this context, 2-hydroxioleic acid (2OHOA, LAM561, INN: idroxioleic acid) has been developed for the treatment of GBM and is currently running a phase IIB/III clinical trial for newly diagnosed GBM patients. 2OHOA modulates the lipid composition and structure of cancer cells, increasing membranes fluidity and altering the activity of membrane-associated proteins, inhibiting the proliferation, inducing ER stress and differentiation, and finally triggering cell death by autophagy. The Notch signaling pathway has been highly related to tumorigenesis and cell survival driving the pathogenesis of GBM. In this work, we studied whether 2OHOA modulates the Notch pathway and its relevance in its mechanism of action (MoA) as an antitumoral drug. For this purpose, the 2OHOA’s effect on different components of the pathway was studied by western-blot, Q-PCR, and confocal microscopy. In addition, Notch receptor processing and NICD formation (final effector) were analyzed by cell fractionation and Notch processing enzymes activity, like furin, was evaluated upon 2OHOA treatment. First, the inhibition of this pathway in GBM cells by 2OHOA was confirmed by (i) lower expression levels of some of its components (Notch1, Notch3, and Jagged) and target genes (Hes1, CD3), (ii) less nuclear presence of NICD and Hes1 after 2OHOA treatment, (iii) accumulation of full-length Notch receptor in the membranes, impairing its processing and the NICD formation. Second, the relevance of Notch pathway in 2OHOA’s MoA was determined by the partial hindering of 2OHOA antiproliferative effect by Hes1 overexpression. Moreover, the reduction of Hes1 expression induced by the drug in different GBM cells correlated positively with their sensitivity to 2OHOA. Finally, 2OHOA downregulated furin-like proteases activity by physical association, an enzyme responsible for the Notch processing first step. All together reveals that the inhibition of Notch pathway by 2OHOA plays a role in its antitumoral effect, and this event is unleashed by the direct furin enzyme inhibition, identifying it as a novel target for this drug in the GBM and other pathologies treatment. Citation Format: Raquel Rodríguez-Lorca, Roberto Beteta-Göbel, Ramón Román, Manuel Torres, Victoria Llado, Pablo V. Escribá, Paula Fernández-García. Furin and Notch signaling pathway as part of the 2OHOA landscape against glioblastoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4869.

Identification of Prognostic Aging-Related Genes Associated with Immune Cell Infiltration in Glioblastoma

Background. Aging is recognized as a main tumor risk factor, and thus aging has become a field of interest in the tumor research field. Glioblastoma multiforme represents the most typical primary malignant intracranial tumor, particularly in the elderly. However, the association between aging-related genes (AGs) and GBM prognosis remains unknown. As a result, the primary goal of this study was to determine the association among AGs and the prognosis of GBM. Methods. A total of 307 human AGs were downloaded from the HAGR database, while the expression profiles of GSE4290 and GSE4412 were obtained from the GEO database. Furthermore, data on GBM expression profiles were obtained from the Chinese Glioma Genome Atlas (CGGA) database. The DEAGs that were differentially expressed among the AG and GBM gene expression profiles derived from GSE4290 were then identified, followed by functional analysis of the DEAGs. The survival-related AGs were then screened using univariate Cox regression analysis , which was used to build and validate a prognostic risk model. Furthermore, the ESTIMATE and CIBERSORT algorithms were utilized to explore the association between the survival-related AGs and the tumor immune microenvironment. Results. In entire, 29 DEAGs were identified in the GSE4290. This was monitored by the construction of the prognosis risk model using four DEAGs from the CGGA training set, including C1QA, CDK1, EFEMP1, and IGFBP2. Next, the risk model was confirmed in the CGGA experiment set and the GSE 4412 dataset. Results showed that C1QA, CDK1, EFEMP1, and IGFBP2 levels were remarkably higher in the high-risk score groups, and they had a good association with immune and stromal scores. Conclusion. A robust prognostic risk model was constructed and validated using four AGs, including C1QA, CDK1, EFEMP1, and IGFBP2, which had a close relationship with the immune microenvironment of GBM. This study offers a new reference to further explore the pathogenesis of GBM and recognize new and more effective GBM treatments.

VEGF gene polymorphisms in Iranian patients with intracranial glioblastoma.

Glioblastoma is one of the most common malignant brain tumors in adults with poor prognosis. Neovascularization is one of the characteristics of these tumors, which is associated with overexpression of vascular endothelial growth factor (VEGF). Accordingly, single nucleotide polymorphisms of this gene could play an important role in structural and functional alterations leading to overexpression of this gene in GBM. A total number of 49 patients with GBM and 50 healthy controls were included in the current study. The Genomic DNA was extracted from brain tumor/tissue samples, and after purification assessment, the alleles, and genotypes of rs3025039 and rs2010963 polymorphisms of the VEGF gene were investigated using T-ARMS-PCR. The "T" allele of rs3025039 was 2.79 times more frequent in GBM patients compared to controls (P=0.01). Moreover, the "CT" genotype was 2.83 times more common among patients (P=0.015), while the "CC" was more frequent in controls (P=0.009). The mean overall survival was significantly different between three genotypes of rs3025039, with the longest survival time in "CT" genotype (15.10±5.21, P=0.041). Besides, rs2010963, was significantly associated with GBM occurrence, with the "G" allele being 1.96 times more frequent in patients (P=0.01), as well as the "GG" genotype, which was 7.87 times more common in patients (P<0.001). Polymorphisms of VEGF could potentially play a role in pathogenesis of GBM, as the allele and genotype distributions of rs3025039 and rs2010963 SNPs were significantly associated with GBM occurrence.

GEN-10 WHOLE GENOME LANDSCAPE OF GLIOBLASTOMA, IDH-WILD TYPE

Abstract Introduction: Glioblastoma, IDH-wild type (GBM) is the most common malignant brain tumor with a dismal prognosis. Although its coding region is well-analyzed, little is yet known about the landscape of whole-genome in GBM. Here, we analyzed whole-genome sequencing data from large cohorts to completely uncover the genetic aberrations in GBM. Methods: We analyzed 281 whole-genome sequencing data of patients with GBM, of which 152 cases are from our cohort with deep coverage (×120) and 129 cases are from a public database. Results: The median numbers of somatic mutations and structural variants (SVs) per case are 3.0/Mb and 62.5, respectively. While a complex SV is rare in other malignant brain tumors such as IDH-mutant glioma (35% of samples), a large proportion of GBM cases (85%) have complex SV with ≥10 breakpoints. CDKN2A/B homozygous deletions (HDs) are usually comprised of a simple deletion in IDH-mutant glioma whereas about a quarter of CDKN2A/B HDs in GBM are induced by complex SVs. In addition, 30.5% of extrachromosomal DNA (ecDNA) involves multiple chromosomes. Taken together, complex SVs could play a key role in the initiation and progression of GBM. Our deep WGS enables us to delineate a fine view of clonal architecture, where mutational signature varies between clonal and subclonal mutations. The majority of clonal mutations consist of the clock-like signature, whereas subclonal mutations have a relatively low proportion of the clock-like signature. Instead, several other signatures including the APOBEC signature significantly increase in subclones, presuming that various mutational processes along with the clock-like signature contribute to the GBM pathogenesis in its progression phase. Conclusions: GBM evolves through exploiting complex structural variants involving multiple driver genes and the accumulation of genetic mutations caused by distinct mechanisms depending on its developmental stage.

DNAR-15. POLYMORPHISM AT P21 CODON 31 PROVIDED A PREDICTION FOR BEVACIZUMAB THERAPY IN GLIOBLASTOMA MULTIFORME

Abstract Glioblastoma (GBM) is a common, malignant brain tumor. While it rarely metastasizes to distant organs, the diffuse invasion of glioma cells within the brain makes it difficult to resect. P21 (Waf-1) is a cyclin-dependent kinase inhibitor that plays an essential role in cell growth arrest, terminal differentiation, and apoptosis. Thus, the existence of natural variants of p21 could be linked to specific cancer. The purpose of this study was to identify the polymorphism variants of p21 codon 31 (Ser31Arg) and to explore its role in the therapy of glioblastoma multiforme. A total of unrelated 99 GBM subjects, were enrolled in the study, and genomic DNA was obtained from each tumor sample for genotyping. Genotyping was performed by polymerase chain reaction (PCR) restriction fragment length polymorphism method (PCR-RFLP analysis. Odds ratios (Ors) and 95% confidence intervals (CIs) were estimated by unconditional logistic regression analysis. We found that among these GBM patients, the distribution of codon 31 polymorphisms was 20.2% for Serine homozygotes (Ser/Ser), 32.3% for arginine homozygotes (Arg/Arg), and 47.5% for Serine/arginine heterozygotes (Ser/Arg). Although the polymorphisms of p21 codon 31 were not directly associated with the overall survival of GBM, both the Arg/Arg and Arg/Ser genotypes were associated with significant benefits in terms of overall survival in patients treated with CCRT plus bevacizumab compared to patients treated with CCRT alone. Our findings suggest that the p21 Ser31Arg polymorphism may play an important role in the pathogenesis and initiation of GBM. Moreover, the polymorphism seems to contribute to a significant prediction at early diagnosis for bevacizumab therapy.