Glioblastoma Multiforme Patients Research Articles

Comparative Analysis of Transcription Factors TWIST2, GATA3, and HES5 in Glioblastoma Multiforme : Evaluating Biomarker Potential and Therapeutic Targets Using In Silico Methods.

Glioblastoma multiforme (GBM) is characterized by substantial heterogeneity and limited therapeutic options. As molecular approaches to central nervous system (CNS) tumors have gained prominence, this study examined the roles of three genes, TWIST2, GATA3, and HES5, known to be involved in oncogenesis, developmental processes, and maintenance of cancer stem cell properties, which have not yet been extensively studied in GBM. This study is the first to present gene expression data for TWIST2, GATA3, and HES5 specifically within the context of GBM patient survival. Gene expression data for TWIST2, GATA3, and HES5 were collected from GBM and normal brain tissues using datasets from The Cancer Genome Atlas (TCGA) via the Genomic Data Commons (GDC) portal and the Genotype-Tissue Expression (GTEx) database. These data were rigorously analyzed using in silico methods. All three genes were significantly more expressed in GBM tissues than in normal tissues. TWIST2 and GATA3 were linked to lower survival rates in GBM patients. Interestingly, higher HES5 levels were associated with better survival rates, suggesting a complex role that needs more investigation. This study shows that TWIST2, GATA3, and HES5 could help predict outcomes in GBM patients. Our multigene model offers a better understanding of GBM and points to new treatment options, bringing hope for improved therapies and patient outcomes. This research advances our knowledge of GBM and highlights the potential of molecular diagnostics in oncology.

Harnessing the role of aberrant cell signaling pathways in glioblastoma multiforme: a prospect towards the targeted therapy.

Glioblastoma Multiforme (GBM), designated as grade IV by the World Health Organization, is the most aggressive and challenging brain tumor within the central nervous system. Around 80% of GBM patients have a poor prognosis, with a median survival of 12-15months. Approximately 90% of GBM cases originate from normal glial cells via oncogenic processes, while the remainder arise from low-grade tumors. GBM is notorious for its heterogeneity, high recurrence rates, invasiveness, and aggressive behavior. Its malignancy is driven by increased invasive migration, proliferation, angiogenesis, and reduced apoptosis. Throughout various stages of central nervous system (CNS) development, pivotal signaling pathways, including Wnt/β-catenin, Sonic hedgehog signaling (Shh), PI3K/AKT/mTOR, Ras/Raf/MAPK/ERK, STAT3, NF-КB, TGF-β, and Notch signaling, orchestrate the growth, proliferation, differentiation, and migration of neural progenitor cells in the brain. Numerous upstream and downstream regulators within these signaling pathways have been identified as significant contributors to the development of human malignancies. Disruptions or aberrant activations in these pathways are linked to gliomagenesis, enhancing the invasiveness, progression, and aggressiveness of GBM, along with epithelial to mesenchymal transition (EMT) and the presence of glioma stem cells (GSCs). Traditional GBM treatment involves surgery, radiotherapy, and chemotherapy with Temozolomide (TMZ). However, most patients experience tumor recurrence, leading to low survival rates. This review provides an overview of the major cell signaling pathways involved in gliomagenesis. Furthermore, we explore the signaling pathways leading to therapy resistance and target key molecules within these signaling pathways, paving the way for the development of novel therapeutic approaches.

Role of Circular RNA MMP9 in Glioblastoma Progression: From Interaction With hnRNPC and hnRNPA1 to Affecting the Expression of BIRC5 by Sequestering miR-149.

Glioblastoma multiforme (GBM) presents a significant challenge in neuro-oncology due to its aggressive behavior and self-renewal capacity. Circular RNAs (circRNAs), a subset of non-coding RNAs (ncRNAs) generated through mRNA back-splicing, are gaining attention as potential targets for GBM research. In our study, we sought to explore the functional role of circMMP9 (circular form of matrix metalloproteinase-9) as a promising therapeutic target for GBM through bioinformatic predictions and human data analysis. Our results suggest that circMMP9 functions as a sponge for miR-149 and miR-542, both upregulated in GBM based on microarray data. Kaplan-Meier analysis indicated that reduced levels of miR-149 and miR-542 correlate with worse survival outcomes in GBM, suggesting their role as tumor suppressors. Importantly, miR-149 has been demonstrated to inhibit the expression of BIRC5 (baculoviral inhibitor of apoptosis repeat-containing 5 or survivin), a significant promoter of proliferation in GBM. BIRC5 is not only upregulated in GBM but also in various other cancers, including neuroblastoma and other brain cancers. Our protein-protein interaction analysis highlights the significance of BIRC5 as a central hub gene in GBM. CircMMP9 seems to influence this complex relationship by suppressing miR-149 and miR-542, despite their increased expression in GBM. Additionally, we found that circMMP9 directly interacts with heterogeneous nuclear ribonucleoproteins C and A1 (hnRNPC and A1), although not within their protein-binding domains. This suggests that hnRNPC/A1 may play a role in transporting circMMP9. Moreover, RNA-seq data from GBM patient samples confirmed the increased expression of BIRC5, PIK3CB, and hnRNPC/A1, further emphasizing the potential therapeutic significance of circMMP9 in GBM. In this study, we propose for the first time a new epigenetic regulatory role for circMMP9, highlighting a novel aspect of its oncogenic function. circMMP9 may regulate BIRC5 expression in GBM by sponging miR-149 and miR-542. BIRC5, in turn, suppresses apoptosis and enhances proliferation in GBM. Nonetheless, more extensive studies are advised to delve deeper into the roles of circMMP9, especially in the context of glioma.

The prognostic significance of synchronous metastasis in glioblastoma multiforme patients: a propensity score-matched analysis using SEER data.

Glioblastoma multiforme (GBM) with synchronous metastasis(SM) is a rare occurrence. We extracted the data of GBM patients from the SEER database to look into the incidence of SM in GBM, determine the prognostic significance of SM in GBM, and assess therapeutic options for patients presenting with SM. From 2004 to 2015, information on GBM patients was obtained from the Surveillance, Epidemiology, and End Results (SEER) database. The propensity score matching (PSM) method was employed to mitigate confounding factors between SM and non-SM groups, subsequently investigating the prognostic significance of SM in patients with GBM. Multivariate Cox proportional hazards regression analyses were employed to identify independent prognostic variables for GBM patients with SM. A forest plot was used to visualize the results. A cohort of 19,708 patients was obtained from the database, among which 272 (1.4%) had SM at the time of diagnosis. Following PSM at a 3:1 ratio, in both univariate and multivariate cox regression analysis, SM (HR = 1.27, 95% CI: 1.09-1.46) was found to be an independent predictive predictor for GBM patients. Furthermore, the Cox proportional hazard forest plot demonstrated that independent risk variables for GBM patients with SM included age (Old vs. Young, HR = 1.44, 95% CI: 1.11-1.88), surgery (biopsy vs. no surgery, HR = 0.67, 95% CI: 0.46-0.96;Subtotal resection vs. no surgery, HR = 0.47, 95% CI: 0.32-0.68;Gross total resection vs. no surgery, HR = 0.44, 95% CI: 0.31-0.62), radiotherapy (HR = 0.58, 95% CI: 0.41-0.83), and chemotherapy (HR = 0.51, 95% CI: 0.36-0.72). The predictive value of SM in GBM was determined by this propensity-matched analysis using data from the SEER database. Radiotherapy, chemotherapy, and surgery constitute an effective treatment regimen for patients with SM. A more positive approach toward the use of aggressive treatment for GBM patients with SM may be warranted.

The Implication of Photodynamic Therapy Applied to the Level of Tumor Resection on Postoperative Cerebral Edema and Intracranial Pressure Changes in Gliomas.

The aim of our study was to explore the factors influencing cerebral edema and intracranial pressure in glioblastoma multiforme (GBM) patients who undergo photodynamic therapy (PDT) after resection. This was a retrospective controlled study of GBM patients treated with PDT-assisted resections of varying scope from May 2021 to August 2023. The baseline clinical data, cerebral edema volumes, intracranial pressure values, and imaging data of the GBM patients were collected for statistical analysis. A total of 56 GBM patients were included. Thirty of the patients underwent gross total resection (GTR), and the other 26 patients underwent subtotal resection (STR). We found that the cerebral edema volume and the mean intracranial pressure in patients who underwent GTR were lower than those in patients who underwent STR. Moreover, univariate analysis showed that the scope of tumor resection was an independent factor affecting cerebral edema and intracranial pressure after PDT. Compared with STR, PDT combined with GTR significantly reduced postoperative brain edema volume and intracranial pressure in GBM patients.

Implantable Microneedle-Mediated Eradication of Postoperative Tumor Foci Mitigates Glioblastoma Relapse.

Glioblastoma multiforme (GBM) remains incurable despite multimodal treatments after surgical debulking. Almost all patients with GBM relapse within a narrow margin (2-3cm) of the initial resected lesion due to the unreachable residual cancerous cells. Here, a completely biodegradable microneedle for surgical cavity delivery glioblastoma-associated macrophages (GAMs)-activating immune nano-stimulator that mitigates glioblastoma relapse is reported. The residual tumor lesion-directed biocompatible microneedle releases the nano-stimulator and toll-like receptor 9 agonist in a controlled manner until the microneedles completely degrade over 1 week, efferently induce in situ phonotypic shifting of GAMs from anti- to pro-inflammatory and the tumor recurrence is obviously inhibited. The implantable microneedles offer a significant improvement over conventional transdermal ones, as they are 100% degradable, ensuring safe application within surgical cavities. It is also revealed that the T cells are recruited to the tumor niche as the GAMs initiate anti-tumor response and eradicate residual GBM cells. Taken together, this work provides a potential strategy for immunomodulating the postoperative tumor niche to mitigate tumor relapse in GBM patients, which may have broad applications in other malignancies with surgical intervention.

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.

Non-coding RNAs as Key Regulators of the Notch Signaling Pathway in Glioblastoma: Diagnostic, Prognostic, and Therapeutic Targets.

Glioblastoma multiforme (GBM) is a highly invasive brain malignancy originating from astrocytes, accounting for approximately 30% of central nervous system malignancies. Despite advancements in therapeutic strategies including surgery, chemotherapy, and radiopharmaceutical drugs, the prognosis for GBM patients remains dismal. The aggressive nature of GBM necessitates the identification of molecular targets and the exploration of effective treatments to inhibit its proliferation. The Notch signaling pathway, which plays a critical role in cellular homeostasis, becomes deregulated in GBM, leading to increased expression of pathway target genes such as MYC, Hes1, and Hey1, thereby promoting cellular proliferation and differentiation. Recent research has highlighted the regulatory role of non-coding RNAs (ncRNAs) in modulating Notch signaling by targeting critical mRNA expression at the post-transcriptional or transcriptional levels. Specifically, various types of ncRNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), have been shown to control multiple target genes and significantly contribute to the carcinogenesis of GBM. Furthermore, these ncRNAs hold promise as prognostic and predictive markers for GBM. This review aims to summarize the latest studies investigating the regulatory effects of ncRNAs on the Notch signaling pathway in GBM.

Reproducible and Interpretable Machine Learning-Based Radiomic Analysis for Overall Survival Prediction in Glioblastoma Multiforme

Purpose: To develop and validate an MRI-based radiomic model for predicting overall survival (OS) in patients diagnosed with glioblastoma multiforme (GBM), utilizing a retrospective dataset from multiple institutions. Materials and Methods: Pre-treatment MRI images of 289 GBM patients were collected. From each patient’s tumor volume, 660 radiomic features (RFs) were extracted and subjected to robustness analysis. The initial prognostic model with minimum RFs was subsequently enhanced by including clinical variables. The final clinical–radiomic model was derived through repeated three-fold cross-validation on the training dataset. Performance evaluation included assessment of concordance index (C-Index), integrated area under curve (iAUC) alongside patient stratification into low and high-risk groups for overall survival (OS). Results: The final prognostic model, which has the highest level of interpretability, utilized primary gross tumor volume (GTV) and one MRI modality (T2-FLAIR) as a predictor and integrated the age variable with two independent, robust RFs, achieving moderately good discriminatory performance (C-Index [95% confidence interval]: 0.69 [0.62–0.75]) with significant patient stratification (p = 7 × 10−5) on the validation cohort. Furthermore, the trained model exhibited the highest iAUC at 11 months (0.81) in the literature. Conclusion: We identified and validated a clinical–radiomic model for stratification of patients into low and high-risk groups based on OS in patients with GBM using a multicenter retrospective dataset. Future work will focus on the use of deep learning-based features, with recently standardized convolutional filters on OS tasks.

Introduction of MYBL2 as a common regulator between AHR and RELA: Its relationship with lnc-UCC and lnc-HOTTIP in glioblastoma multiforme

This study aimed to validate the experimental gene expression level of a common gene in the Aryl Hydrocarbon Receptor (AHR) and RELA in glioblastoma multiforme (GBM) using bioinformatics.RNAseq data was analyzed to identify differentially expressed genes (DEGs), and LncRNAs related to the regulation of the founded gene were identified by the RNA Interactome Database. Ten healthy controls and 28 GBM patients' tissue samples were gathered, and the change in gene expression levels was measured by real-time PCR.The results showed that MYBL2 is a common regulator between the AHR and RELA, and the expression of MYBL2, lnc-UCC, and lnc-HOTTIP genes was significantly increased in the GBM group.Lnc-UCC expression showed significant positive correlations with MYBL2 and lnc-HOTTIP expression levels. Further investigation into these genes and their regulatory mechanisms is need.

A Platform to Establish a Working Hierarchy of Glioblastoma Multiforme Cells:

Glioblastoma multiform (GBM), a grade IV glioma, is the most common and aggressive cancer in the central nervous system. Current treatment for GBM includes surgical resection, radiation, and the frontline DNA alkylating drug, temozolomide (TMZ). The current median survival for GBM patients is about 14.5 months with 5% patients surviving up to 5 years. We propose that discerning distinct subsets within heterogeneous GBM will provide avenues for research to improve new therapies. We used different methods to isolate GBM cell subsets. These include stable transfectants of GBM cell lines with a lentiviral system in which green fluorescence protein (GFP) is regulated with tandem repeats of Oct4a and Sox2 response elements. Parallel studies with a plasmid using the full-length regulatory region of Oct4a indicated reduced efficiency in separating cell subsets, relative to SORE6-GFP lentivirus. Stem cell-linked gene expressions and function studies such as ALDH1, tumorsphere and in vivo passaging of GFP hi subsets confirmed the presence of cancer stem cells (CSCs). We also studied a more efficient method that could be relevant for primary GBM cells. We selected tumorspheres by plating heterogeneous GBM cells and then serially passaged the spheres. Studies for stem cell genes indicated that this method could be used for primary GBM cells. Overall, this study provided insights into methods to isolate GBM subsets, including primary GBM cells. The advantages of the methods are discussed.

Long Non-Coding RNA CRNDE, LINC00957, and AC072061.1 as a Promising Diagnostic and Prognostic Biomarker in Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is one of the most invasive types of brain cancer. LncRNAs can be considered a new prognostic and diagnostic biomarker in GBM. This study comprehensively explored the interaction of lncRNAs with mRNAs in the TCGA database and proposed a novel promising biomarker with favorable diagnostic and prognostic values. The public data of RNA-seq and related clinical data were downloaded from the TCGA database. Differential expression analysis was conducted in R. GO and KEGG signaling pathways were used for enrichment. The STRING database was used for PPI analysis. CE-network was constructed by STAR database. Kaplan-Meier survival analysis and ROC curve analysis to indicate the biomarkers' diagnostic and prognostic values. Differentially expressed data illustrated that 4428 mRNAs were differentially expressed in GBM. The GO and KEGG pathway analysis showed that the differentially expressed mRNAs were enriched in critical biological processes. The PPI showed that WEE1, BARD1, and CDK6 were the important PPI hubs. The ceRNA network data demonstrated critical lncRNAs. The data revealed that the lncRNA CRNDE, LINC00957, AC072061.1, AC068888.1, and DBH-AS1 are potential diagnostic prognostic biomarkers in the GBM patients. Altogether, we demonstrated lncRNA, and mRNA interaction and mentioned regulatory networks, considered a therapeutic option in GBM. In addition, we proposed potential diagnostic and prognostic biomarkers for the patients.

Proteomics Studies on Extracellular Vesicles Derived from Glioblastoma: Where Do We Stand?

Like most tumors, glioblastoma multiforme (GBM), the deadliest brain tumor in human adulthood, releases extracellular vesicles (EVs). Their content, reflecting that of the tumor of origin, can be donated to nearby and distant cells which, by acquiring it, become more aggressive. Therefore, the study of EV-transported molecules has become very important. Particular attention has been paid to EV proteins to uncover new GBM biomarkers and potential druggable targets. Proteomic studies have mainly been performed by "bottom-up" mass spectrometry (MS) analysis of EVs isolated by different procedures from conditioned media of cultured GBM cells and biological fluids from GBM patients. Although a great number of dysregulated proteins have been identified, the translation of these findings into clinics remains elusive, probably due to multiple factors, including the lack of standardized procedures for isolation/characterization of EVs and analysis of their proteome. Thus, it is time to change research strategies by adopting, in addition to harmonized EV selection techniques, different MS methods aimed at identifying selected tumoral protein mutations and/or isoforms due to post-translational modifications, which more deeply influence the tumor behavior. Hopefully, these data integrated with those from other "omics" disciplines will lead to the discovery of druggable pathways for novel GBM therapies.

Radiomics analysis of cerebral blood flow suggests a possible link between perfusion homogeneity and poor glioblastoma multiforme prognosis

Objectives. This study investigates the association between cerebral blood flow (CBF) and overall survival (OS) in glioblastoma multiforme (GBM) patients receiving chemoradiation. Identifying CBF biomarkers could help predict patient response to this treatment, facilitating the development of personalized therapeutic strategies. Materials and Methods. This retrospective study analyzed CBF data from dynamic susceptibility contrast (DSC) MRI in 30 newly diagnosed GBM patients (WHO grade IV). Radiomics features were extracted from CBF maps, tested for robustness, and correlated with OS. Kaplan-Meier analysis was used to assess the predictive value of radiomic features significantly associated with OS, aiming to stratify patients into groups with distinct post-treatment survival outcomes. Results. While mean relative CBF and CBV failed to serve as independent prognostic markers for OS, the prognostic potential of radiomic features extracted from CBF maps was explored. Ten out of forty-three radiomic features with highest intraclass correlation coefficients (ICC > 0.9), were selected for characterization. While Correlation and Zone Size Variance (ZSV) features showed significant OS correlations, indicating prognostic potential, Kaplan-Meier analysis did not significantly stratify patients based on these features. Visual analysis of the graphs revealed a predominant association between the identified radiomic features and OS under two years. Focusing on this subgroup, Correlation, ZSV, and Gray-Level Nonuniformity (GLN) emerged as significant, suggesting that a lack of heterogeneity in perfusion patterns may be indicative of a poorer outcome. Kaplan-Meier analysis effectively stratified this cohort based on the features mentioned above. Receiver operating characteristic (ROC) analysis further validated their prognostic value, with ZSV demonstrating the highest sensitivity and specificity (0.75 and 0.85, respectively). Conclusion. Our findings underscored radiomics features sensitive to CBF heterogeneity as pivotal predictors for patient stratification. Our results suggest that these markers may have the potential to identify patients who are unlikely to benefit from standard chemoradiation therapy.

499TiP A phase II study of BPM31510 (a lipid nanodispersion of oxidized CoQ10) with vitamin K in combination with standard of care (SOC) RT and TMZ in glioblastoma multiforme (GBM) patients without prior therapy

499TiP A phase II study of BPM31510 (a lipid nanodispersion of oxidized CoQ10) with vitamin K in combination with standard of care (SOC) RT and TMZ in glioblastoma multiforme (GBM) patients without prior therapy

472P Comprehensive quinomics assessment of BPM31510IV treatment in advanced glioblastoma multiforme patients

472P Comprehensive quinomics assessment of BPM31510IV treatment in advanced glioblastoma multiforme patients

Bioinformatics analysis of SH2D4A in glioblastoma multiforme to evaluate immune features and predict prognosis.

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain cancer in adults. This study aimed to obtain data on immune cell infiltration based on public datasets and to examine the prognostic significance of SH2 domain containing 4A (SH2D4A) for GBM. SH2D4A expression in GBM was analyzed using a Tumor Immunity Estimation Resource (TIMER) 2.0 dataset, and a gene expression profile interaction analysis (GEPIA), and the results were validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The Chinese Glioma Genome Atlas (CGGA) dataset was used to assess the effect of SH2D4A on GBM patient survival. The SH2D4A co-expression network of the LinkedOmics dataset and GeneMANIA dataset was also investigated. Least absolute shrinkage and selection operator (LASSO) regression models and a nomogram were constructed to assess the prognosis of GBM patients. A Gene Set Enrichment Analysis (GSEA) was performed using The Cancer Genome Atlas (TCGA) dataset to find functional differences. The relationship between SH2D4A expression and tumor-infiltrating immune cells was analyzed using xCELL, the Cell Type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) algorithm, and the TIMER dataset. We discovered that SH2D4A expression was upregulated in GBM patients, and elevated SH2D4A expression was also substantially correlated with tumor grade. The survival curve analysis and multivariate Cox regression analysis showed that high SH2D4A expression was a significant independent predictor of poor overall survival (OS) in GBM patients. The immunoassay results suggested that altered SH2D4A expression may affect the immune infiltration of GBM tissues and thus the survival outcomes of GBM patients. In addition to being a possible prognostic marker and therapeutic target for GBM, SH2D4A may also accelerate the progression of GBM.

The role of ALDH1A1 in glioblastoma proliferation and invasion

High-grade gliomas, including glioblastoma multiforme (GBM), continue to be a leading aggressive brain tumor in adults, marked by its rapid growth and invasive nature. Aldehyde dehydrogenase 1 family, member A1 (ALDH1A1), an enzyme, plays a significant role in tumor progression, yet its function in high-grade gliomas is still poorly investigated. In this study, we evaluated ALDH1A1 levels in clinical samples of GBM. We also assessed the prognostic significance of ALDH1A1 expression in GBM and LGG (low grade glioma) patients using TCGA (The Cancer Genome Atlas) database analysis. The MTT and transwell assays were utilized to examine cell growth and the invasive capability of U87 cells, respectively. We quantitatively examined markers for cell proliferation (Ki-67 and cyclin D1) and invasion (MMP2 and 9). A Western blot test was conducted to determine the downstream signaling of ALDH1A1. We found a notable increase in ALDH1A1 expression in high-grade gliomas compared to their low-grade counterparts. U87 cells that overexpressed ALDH1A1 showed increased cell growth and invasion. We found that ALDH1A1 promotes the phosphorylation of AKT, and inhibiting AKT phosphorylation mitigates the ALDH1A1's effects on tumor growth and migration. In summary, our findings suggest ALDH1A1 as a potential therapeutic target for GBM treatment.

AB038. Establishing a reliable semi-automated segmentation method for assessing chemoradiotherapy effects on the non-tumoral brain.

Current voxel-based morphometry (VBM) studies of chemoradiotherapy effects on healthy tissues of the glioblastoma multiforme (GBM) brain face a challenge with neuroanatomical distortions (tumor, tumor edema, and resection cavities) and limited comparisons can be drawn across studies due to lack of a universally accepted software package. Our aim is to compare current semi-automated segmentation methods and optimize them for reliability in investigating the effects of chemoradiotherapy on GBM patients. A publicly available dataset was used based on predefined inclusion and exclusion criteria. VBM pipelines CAT12 and FSL were tested and optimized to reduce the impact of neuroanatomical distortions. T1-weighted images were screened, and post-processed with FSL and CAT12. Gray matter (GM) and white matter (WM), and cerebrospinal fluid (CSF) volumes of whole brain, tumour-containing and non-tumor containing hemispheres, pre- and post-chemoradiotherapy were calculated and analyzed with Wilcoxon signed-rank tests. Agreement and consistency between FSL and CAT12 were assessed using Bland-Altman plots and intraclass correlation coefficients (ICCs). Post-chemoradiotherapy GM volumes were significantly reduced in whole brain with a compensatory significant increase in CSF volumes, while WM volumes had no significant changes. Similar trends were noted in tumor-containing and non-tumor-containing hemispheres. Bland-Altman plots showed good agreement between FSL and CAT12 processed GM and WM volumes of whole brain, tumor-containing, and non-tumor-containing hemispheres. ICC ≥0.70 was observed in GM [0.70 (0.53-0.82)] and WM [0.75 (0.60-0.85)] volumes of non-tumor-containing hemisphere, and WM [0.71 (0.55-0.83)] volumes of whole brain. GM volumes of tumor-containing hemisphere had good agreement but surprisingly, poor consistency [0.50 (0.25-0.68)]. CSF volumes in non-tumor-containing hemisphere had better agreement and consistency [0.55 (0.32-0.71)] than whole brain [0.49 (0.25-0.67)] and tumor-containing hemisphere CSF [0.36 (0.10-0.58)] volumes. Visual inspection revealed both CAT12 and FSL mis-segmented in the presence of neuroanatomical distortion although CAT12 was more susceptible in the presence of a hematoma. VBM studies of chemoradiotherapy effects on the brain post-tumor resection remain challenging due to neuroanatomical distortions. A reliable alternative is to use non-tumor-containing hemispheres with no anatomical distortion. Should tumor-containing brains be used, FSL is a more suitable choice, especially in the presence of hematoma distortion.

AB042. Combined anti-PD-L1 and anti-VEGFR2 therapy promotes the antitumor immune response in glioblastoma multiforme by reprogramming tumor microenvironment.

Inhibitors of programmed cell death ligand 1 (PD-L1) and vascular endothelial growth factor receptor 2 (VEGFR2) are commonly used in the clinic, but they are beneficial for only a minority of glioblastoma multiforme (GBM) patients. GBM has significant immunosuppressive properties, and there are many immunosuppressive cells and dysfunctional effector T-cell in the tumor microenvironment (TME), which is one of the important reasons for the failure of clinical treatment of GBM. P21-activated kinase 4 (PAK4) is a threonine protein kinase, and as a pivotal immune suppressor in the TME. PAK4 knockdown attenuates vascular abnormalities and promotes T-cell infiltration. Using RNA sequencing (RNA-seq) technology, western blotting, and immunofluorescence, we identified changes in genes expression following VEGFR2 knockdown. The impact of anti-PD-L1 and anti-VEGFR2 on GBM cells apoptosis was assessed using coculture assays, western blotting, and flow cytometry. Additionally, the therapeutic efficacy of anti-PD-L1 and anti-VEGFR2 therapy was evaluated through in vivo experiments, immunohistochemistry, and immunofluorescence. Our studies revealed that VEGFR2 binds and phosphorylates signal transducer and activator of transcription 3 (p-STAT3), thereby regulating the expression of PAK4. Anti-PD-L1 and anti-VEGFR2 therapy can increase the secretion of interferon-gamma (IFN-γ), granzyme B, and perforin by immune cells and promoting the cytotoxic effects of cytotoxic cluster of differentiation 8 (CD8)+ T cells, and overexpression of PAK4 could reverse this effect. We also demonstrated that combination therapy with anti-PD-L1 and anti-VEGFR2 agents prevents tumor growth in an intracranial tumor model. Our results support that anti-VEGFR2 therapy can downregulate PAK4, reprogram the TME by increasing CD8+ T cells infiltration and activation, and enhance the therapeutic effect of anti-PD-L1 therapy on GBM cells.