Type Of Brain Tumor Research Articles

Abstract B043: BDNF-TrkB.T1 signaling increases neutrophil recruitment and epithelial-to- mesenchymal transition in gliomas

Abstract Gliomas are the most common type of brain tumor in both children and adults. Communication between glioma cells and the brain tumor microenvironment (TME) is a fundamental aspect of brain cancer pathophysiology. Glioma cells secrete factors that act as chemoattractants, influencing the TME. In addition, neuronal activity within the TME drives the proliferation and growth of gliomas through paracrine signaling, with brain-derived neurotrophic factor (BDNF) being a key mediator. BDNF binds with high affinity to the tropomyosin receptor kinase B (TrkB). Recent work from our group has demonstrated that the TrkB.T1 splice variant is upregulated in human gliomas. Furthermore, TrkB.T1 overexpression enhances tumor aggressiveness in vivo and is associated with the downregulation of genes involved in tumor cell recognition and elimination. However, the role of the TrkB.T1 splice variant in the bidirectional communication between glioma cells and the surrounding microenvironment remains unexplored. Our aim was to investigate whether the increased levels of TrkB.T1 observed in gliomas contribute to modulating immune responses. We investigated the immune cell heterogeneity associated with elevated TrkB.T1 levels in vivo using a glioma mouse model engineered with RCAS/tv-a technology. Tumors overexpressing TrkB.T1 exhibited increased neutrophil recruitment, a phenomenon linked to tumor growth, metastasis and therapeutic resistance. To further dissect the signaling mechanisms underlying the BDNF-TrkB.T1 axis, we conducted in vitro studies using glioma stem cells (GSCs) that express high levels of TrkB.T1. GSCs were treated with BDNF, after which the conditioned media was analyzed using a cytokine multiplex assay, and cell lysates were subjected to proteomic analysis. Our findings revealed that TrkB.T1 significantly upregulates key chemokines previously implicated in neutrophil recruitment. Moreover, BDNF signaling increased the expression of N-cadherin, β- catenin, and Snail, markers indicative of the epithelial-to-mesenchymal transition (EMT) phenotype. To further explore the role of TrkB.T1, we used CRISPR/Cas9-based genome editing to knock down TrkB.T1 in GSCs. In conclusion, our findings suggest that the highly expressed TrkB.T1 receptor in gliomas contributes to creating an immunosuppressive microenvironment by recruiting neutrophils and promoting EMT. These insights highlight TrkB.T1 as a potential therapeutic target for modulating glioma-immune cell interactions, which could be crucial in curbing disease progression. Citation Format: Leyre Merino-Galan, Sergio Ortiz-Espinosa, Hawa L. Jagana, John M. Hemenway, Ashmitha Rajendran, Taylor S. Jackson, Daniel A. Kuppers, Sonali Arora, Patrick J. Paddison, Siobhan S. Pattwell. BDNF-TrkB.T1 signaling increases neutrophil recruitment and epithelial-to- mesenchymal transition in gliomas [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B043.

Analysis of Circulating Plasma MicroRNA Profile in Low-Grade and High-Grade Glioma – A Cross-Sectional Study

Background Glioma is the second most common type of brain tumor, accounting for 24% of all brain tumor cases. The current diagnostic procedure is through an invasive tissue sampling to obtain histopathological analysis, however, not all patients are able to undergo a high-risk procedure. Circulating microRNAs (miRNAs) are considered as promising biomarkers for glioma due to their sensitivity, specificity, and non-invasive properties. There is currently no defined miRNA profile that contributes to determining the grade of glioma. This study aims to find the answer for “Is there any significant miRNA that able to distinguish different grades of glioma?”. Methods This study was conducted to compare the expression of miRNAs between low-grade glioma (LGG) and high-grade glioma (HGG). Eighteen blood plasma samples from glioma patients and 6 healthy controls were analyzed for 798 human miRNA profiles using NanoString nCounter Human v3 miRNA Expression Assay. The differential expressions of miRNAs were then analyzed to identify the differences in miRNA expression between LGG and HGG. Results Analyses showed significant expressions in 12 miRNAs between LGG and HGG, where all of them were downregulated. Out of these significant miRNAs, miR-518b, miR-1271-3p, and miR-598-3p showed the highest potential for distinguishing HGG from LGG, with area under curve (AUC) values of 0.912, 0.889, and 0.991, respectively. Conclusion miR-518b, miR-1271-3p, and miR-598-3p demonstrate significant potentials in distinguishing LGG and HGG.

EXTH-52. SIMULTANEOUS TARGETING OF TUMOR CELLS AND TUMOR-ASSOCIATED MACROPHAGES TO REPROGRAM GLIOBLASTOMA BY TUMOR-SUPPRESSIVE MICRORNA

Abstract Glioblastoma (GBM) is the most aggressive type of primary brain tumors due in part to cell-intrinsic and cell-extrinsic mechanisms. The ability of GBM tumor to not only resist conventional therapies but also induce an immunosuppressive tumor microenvironment (TME) is thought to underlie the failure of immunotherapies. Thus, strategies to target both tumor cells and immunosuppressive immune cells, such as tumor-associated macrophages (TAMs), are of great interest. The ability of microRNA (miRNA) to target multiple genes is favorable to alter the character of the TME and cancer cells. Previously, we have shown that tumor suppressive miRNA, miR-138, can effectively regulate the genes in GBM cells relating to cell proliferation and viability. The exogenous delivery of miRNAs, however, has been limited due to the lack of delivery mechanisms that minimize off target effects. We argue that extracellular vesicles (EVs) are an ideal modality of targeted delivery for therapeutic miRNA, which we can accomplish by decorating the EV surface with cancer specific ligands, such as folate. Here, we report that trypsin digestion of the EV surface can increase the surface labeling efficiency for cancer targeting ligands. Folate-labeled trypsinized EVs effectively targeted folate receptor (FR) positive GBM cells and TAMs, delivering miR-138 in in vitro and in vivo orthotopic intracranial murine models of GBM. This simultaneous delivery decreased cancer cell proliferation and altered macrophage polarization through the inhibition of known target genes, phenotypically reprogramming both cancer cells and TAMs. To our knowledge, this is the first preclinical study attempting to target both tumor cells and innate immunity by delivering tumor suppressive miR-138 using a trypsinized EV-based RNA delivery system. These findings can be rapidly translated into a novel therapeutic option for GBM patients.

STEM-12. A NEURONAL STEM-LIKE PHENOTYPE IN GRADE 4 IDH-MUTANT ASTROCYTOMA WITH CDKN2A/B LOSS IS ASSOCIATED WITH CUX2 DEFICIENCY

Abstract Diffuse gliomas represent the most common type of primary adult malignant brain tumor historically diagnosed and graded from histologic criteria alone. Gliomas harboring isocitrate dehydrogenase (IDH) 1 or 2 mutations are associated with lower grade tumors and portend a favorable prognosis relative to IDH-wildtype glioma. However, the loss of CDKN2A/B in IDH-mutant astrocytoma confers an aggressive high grade phenotype and is the strongest implicated molecular alteration associated poor clinical survival, thus is now sufficient to define a grade 4 tumor regardless of histologic grade. However, there remains no effective therapies targeted at molecular subgroups in aggressive gliomas to date. Here, we sought to elucidate the biologic pathways and functional outcomes associated with the acquisition of high-grade behavior under loss of CDKN2A/B in IDH-mutant astrocytoma to inform future therapeutic strategies. We analyzed a cohort of patient IDH-mutant astrocytomas with RNA sequencing data and found the increased expression of regulators of embryonic nervous system development and signaling concurrent with CDKN2A/B loss. Using grade 4 IDH-mutant astrocytoma patient-derived (PDX) and cell-lines harboring CDKN2A/B homozygous deletion, we stably re-expressed p14ARF, p15INK4B, and p16INK4A using a Tet-inducible system. IDH-mutant cell lines with re-expression of p14, p15, or p16 displayed differential transcription factor activation, impaired neurosphere capability, decreased colony formation, and lower neurosphere proliferation. Intriguingly, RNA-seq data revealed CUX2, a transcription factor known to control neuronal precursor behavior, as the likely candidate regulating the differential expression profile across CDKN2A/B status. We observed increased CUX2 expression in cell lines stably re-expressing p14, p15, and p16. We validated the CUX2 signature across publicly available datasets of IDH-mutant astrocytoma where CUX2 expression negatively correlated with loss of CDKN2A/B in patient tumors. Together our work suggests CUX2 deficiency in IDH-mutant astrocytoma with CDKN2A/B deletion enables an increased neuronal stem-like phenotype in these grade 4 tumors.

TMET-18. MANNOSE INHIBITS GLIOMA CELL PROLIFERATION AND POTENTIATES TEMOZOLOMIDE EFFICACY

Abstract Gliomas are among the most aggressive types of brain tumors, often displaying resistance to standard therapies such as temozolomide (TMZ). Recent research suggests that metabolic modulation may influence tumor growth and therapeutic response. This study explores the effects of mannose, a monosaccharide, on glioma cell growth and its potential to enhance the efficacy of TMZ. In vitro experiments were conducted to evaluate the impact of mannose and its combination with TMZ on glioma cells. Cell viability assays, ATP measurements, and flow cytometry (FACS) analysis were performed to assess cell cycle and apoptosis post-treatment with various monosaccharides, including mannose. The synergistic effects of the combined treatment with mannose and TMZ on cell viability were evaluated using Bliss score analysis and FACS. The impact on cancer stem cell characteristics was investigated through neurosphere formation assays, while tumor invasiveness was assessed using 3D invasion assays. Expression of stemness and invasion markers was analyzed by western blot. Differentially expressed gene (DEG) analysis was conducted to assess changes in gene expression related to stemness and invasiveness. Mannose treatment significantly reduced glioma cell viability and ATP levels, indicating decreased metabolic activity. Combined treatment with mannose and TMZ demonstrated a synergistic effect, enhancing cell death compared to either treatment alone, as evidenced by Bliss score and FACS analysis. Co-treatment reduced neurosphere formation and 3D invasion capabilities, with western blot results showing downregulation of stemness and invasion markers. DEG analysis revealed significant changes in gene expression related to stemness and invasiveness with the combined treatment. Mannose significantly impairs glioma cell growth and enhances the therapeutic efficacy of TMZ in vitro. Combining mannose with standard chemotherapy offers a promising strategy for improving glioma treatment outcomes. Further investigation in clinical settings is warranted to validate these findings.

EXTH-49. DEVELOPMENTAL ANTIGENS CAN TARGET EMBRYONAL PEDIATRIC BRAIN CANCERS IN ADOPTIVE CELLULAR THERAPY

Abstract Mutations in tumor neoantigens have shown promise in immunotherapies for many cancers, yet pediatric brain tumors, which typically have a lower mutational burden, offer fewer opportunities to capitalize on these targeted therapies. Studies indicate that medulloblastoma (MB) and brain stem gliomas (BSG) originate from abnormal reactivation of post-natal developmental processes. This led us to investigate whether proteins expressed during the early post-natal development of the mouse cerebellum and brainstem could be powerful antigens to fight MB and BSG, respectively. We performed both in vitro and in vivo studies in mice with the RNA of developmental antigens from the brain stem and cerebellum in an adoptive cellular therapy (ACT) platform. We evaluated the reactivity and therapeutic efficacy of these treatments as sustainable antigenic targets against BSG and MBs. We demonstrate that T cells activated towards these non-mutated, tissue-specific developmental antigens can recognize distinct subtypes of MB and BSG, and activate specifically without cross-reacting to the normal brain. This conferred a survival benefit in established orthotopic models of these pediatric brain tumor types. Our research exhibits the value developmental antigens can offer when serving as tumor rejection antigens in MB and BSG.

Study of Molecular Markers in Glioma and Their Association with Clinicopathological Features.

Central nervous system tumors are a major cause of morbidity and mortality worldwide. The most prevalent type of primary brain tumor is glioma. The exploration of significant genetic, epigenetic, and transcriptional abnormalities has not only improved our understanding of glioma pathogenesis but has also revealed that these molecular alterations can serve as useful diagnostic markers for more precise classification and are linked to better treatment response and prognosis. Hence, incorporating molecular markers into routine tumor classification is a major priority in modern glioma diagnostics. The aim is to assess the mutation status of isocitrate dehydrogenase (IDH)-1, alpha-thalassemia/mental retardation syndrome X-linked (ATRX), and tumor protein 53 in glioma, and look for their association with various clinicopathological features. A single-center prospective cohort study, where all biopsies of glioma (January 2019 to July 2020) were evaluated, and immunohistochemistry was performed to assess the expression of IDH-1, ATRX, p53, and Ki-67 index. The data were analyzed using IBM SPSS-24 software. Immunohistochemistry was performed in 123 consecutive cases of glioma. IDH-1 mutation was noted in 54 (43.9%) cases and these patients frequently presented with "seizures" (P = 0.006). The expression was maximum in World Health Organization (WHO) grade 2 tumors (65.4%) (P < 0.001), with the highest frequency in oligodendrogliomas (100% in WHO grade 2 and 3). Furthermore, these tumors showed lower proliferative indices (P = 0.001). ATRX mutation was noted in 59 (48%) and p53 overexpression was noted in 76 (61.8%) cases. These mutations were significantly associated with astrocytic phenotype (P = 0.03). Molecular characterization of glioma is an important step in modern glioma diagnostics and immunohistochemistry can play an important role. IDH-1 mutation is commonly observed in adults, frontal lobe location, patients presenting with seizures, and WHO grade 2 tumors with the highest frequencies in oligodendrogliomas. ATRX and p53 can be used as surrogate markers for tumors of astrocytic lineage.

Ruta graveolens, but Not Rutin, Inhibits Survival, Migration, Invasion, and Vasculogenic Mimicry of Glioblastoma Cells.

Glioblastoma (GBM) is the most aggressive type of brain tumor, characterized by poor outcome and limited therapeutic options. During tumor progression, GBM may undergo the process of vasculogenic mimicry (VM), consisting of the formation of vascular-like structures which further promote tumor aggressiveness and malignancy. The resulting resistance to anti-angiogenetic therapies urges the identification of new compounds targeting VM. Extracts of natural plants may represent potential therapeutic tools. Among these, components of Ruta graveolens water extract (RGWE) display a wide range of biological activities. To test the effect of RGWE on human GBM and rat glioma cell line VM, tube formation on a gelled matrix was monitored. Quantitative assessment of VM formation shows the clear-cut inhibitory activity of RGWE. Unlike rutin, one of the most abundant extract components, the whole RGWE strongly reduced the migration and invasion of GBM tumor cells. Moreover, RGWE induced cell death of GBM patient-derived cancer stem cells and impaired VM at sub-lethal doses. Overall, our data reveal a marked RGWE-dependent inhibition of GBM cell survival, migration, invasion, and VM formation. Thus, the clear-cut ability of RGWE to counteract GBM malignancy deserves attention, holding the promise to bring natural products to clinical use, thus uncovering new therapeutic opportunities.

SDR2Tr‐GAN: A Novel Medical Image Fusion Pipeline Based on GAN With SDR2 Module and Transformer Optimization Strategy

ABSTRACTIn clinical practice, radiologists diagnose brain tumors with the help of different magnetic resonance imaging (MRI) sequences and judge the type and grade of brain tumors. It is hard to realize the brain tumor computer‐aided diagnosis system only with a single MRI sequence. However, the existing multiple MRI sequence fusion methods have limitations in the enhancement of tumor details. To improve fusion details of multi‐modality MRI images, a novel conditional generative adversarial fusion network based on three discriminators and a Staggered Dense Residual2 (SDR2) module, named SDR2Tr‐GAN, was proposed in this paper. In the SDR2Tr‐GAN network pipeline, the generator consists of an encoder, decoder, and fusion strategy that can enhance the feature representation. SDR2 module is developed with Res2Net into the encoder to extract multi‐scale features. In addition, a Multi‐Head Spatial/Channel Attention Transformer, as a fusion strategy to strengthen the long‐range dependencies of global context information, is integrated into our pipeline. A Mask‐based constraint as a novel fusion optimization mechanism was designed, focusing on enhancing salient feature details. The Mask‐based constraint utilizes the segmentation mask obtained by the pre‐trained Unet and Ground Truth to optimize the training process. Meanwhile, MI and SSIM loss jointly improve the visual perception of images. Extensive experiments were conducted on the public BraTS2021 dataset. The visual and quantitative results demonstrate that the proposed method can simultaneously enhance both global image quality and local texture details in multi‐modality MRI images. Besides, our SDR2Tr‐GAN outperforms the other state‐of‐the‐art fusion methods regarding subjective and objective evaluation.

MiR-3154 promotes glioblastoma proliferation and metastasis via targeting TP53INP1

Glioblastomas (GBM) are most common types of primary brain tumors and miRNAs play an important role in pathogenesis of glioblastomas. Here, we reported a new miRNA, miR-3154, which regulates glioblastoma proliferation and metastasis. miR-3154 was elevated in glioblastoma tissue and cell lines, and its elevation was associated with grade of glioblastomas. Knockdown of miR-3154 in cell lines weakened ability of proliferation and colony formation, and caused cell cycle arrested and higher percentage of apoptosis. Knockdown of miR-3154 also impaired ability of migration and invasion in glioblastoma cells. In mechanism, miR-3154 bound directly to Tumor Protein P53 Inducible Nuclear Protein 1 (TP53INP1), down-regulating TP53INP1 expression at both mRNA and protein level. Silence of TP53INP1 reversed the effect of miR-3154 knockdown on proliferation and metastasis of glioblastoma cells. These findings show that miR-3154 promotes glioblastoma proliferation and metastasis via targeting TP53INP1.

Compression force promotes glioblastoma progression through the Piezo1‑GDF15‑CTLA4 axis.

Glioma, a type of brain tumor, is influenced by mechanical forces in its microenvironment that affect cancer progression. However, our understanding of the contribution of compression and its associated mechanisms remains limited. The objective of the present study was to create an environment in which human brain glioma H4 cells experience pressure and thereby investigate the compressive mechanosensors and signaling pathways. Subsequent time‑lapse imaging and wound healing assays confirmed that 12 h of compression significantly increased cell migration, thereby linking compression with enhanced cell motility. Compression upregulated the expression of Piezo1, a mechanosensitive ion channel, and growth differentiation factor 15 (GDF15), a TGF‑β superfamily member. Knockdown experiments targeting PIEZO1 or GDF15 using small interfering RNA resulted in reduced cell motility, with Piezo1 regulating GDF15 expression. Compression also upregulated CTLA4, a critical immune checkpoint protein. The findings of the present study therefore suggest that compression enhances glioma progression by stimulating Piezo1, promoting GDF15 expression and increasing CTLA4 expression. Thus, these findings provide important insights into the influence of mechanical compression on glioma progression and highlight the involvement of the Piezo1‑GDF15 signaling pathway. Understanding tumor responses to mechanical forces in the brain microenvironment may guide the development of targeted therapeutic strategies to mitigate tumor progression and improve patient outcomes.

Gene Expression Profiling Regulated by lncRNA H19 Using Bioinformatic Analyses in Glioma Cell Lines.

Glioma, the most common type of primary brain tumor, is characterized by high malignancy, recurrence, and mortality. Long non-coding RNA (lncRNA) H19 is a potential biomarker for glioma diagnosis and treatment due to its overexpression in human glioma tissues and its involvement in cell division and metastasis regulation. This study aimed to identify potential therapeutic targets involved in glioma development by analyzing gene expression profiles regulated by H19. To elucidate the role of H19 in A172 and U87MG glioma cell lines, cell counting, colony formation, and wound healing assays were conducted. RNA-seq data analysis and bioinformatics analyses were performed to reveal the molecular interactions of H19. Cell-based experiments showed that elevated H19 levels were related to cancer cell survival, proliferation, and migration. Bioinformatics analyses identified 2,084 differentially expressed genes (DEGs) influenced by H19 which are involved in cancer progression. Specifically, ANXA5, CLEC18B, RAB42, CXCL8, OASL, USP18, and CDCP1 were positively correlated with H19 expression, while CSDC2 and FOXO4 were negatively correlated. These DEGs were predicted to function as oncogenes or tumor suppressors in gliomas, in association with H19. These findings highlight H19 and its associated genes as potential diagnostic and therapeutic targets for gliomas, emphasizing their clinical significance in patient survival.

A Case of Single Surgical Removal of Two Distinct Meningiomas with Different World Health Organization Grades and Subtypes in an Elderly Patient

Meningioma is one of the most common types of benign primary brain tumors in older adults, and multiple meningiomas are reported in fewer than 1% to 10% of cases. However, there is no definitive treatment guideline for patients with multiple meningiomas. An 80-year-old man presented with abruptly impaired cognition and was found to have two distinct meningiomas located in the temporal and frontal lobes. A single frontotemporal craniotomy was performed to remove both tumors. Pathological analysis revealed different subtypes and World Health Organization grades for each mass. The patient showed symptomatic improvement, experienced no postoperative complications, and exhibited no signs of recurrence during a 1-year follow-up period with evaluations at 3-month intervals. Despite the absence of a standard treatment for multiple meningiomas, surgical resection in a single procedure is feasible in selected patients.

Multimodal Connectivity‐Guided Glioma Segmentation From Magnetic Resonance Images via Cascaded 3D Residual U‐Net

ABSTRACTGlioma is a type of brain tumor with a high mortality rate. Magnetic resonance imaging (MRI) is commonly used for examination, and the accurate segmentation of tumor regions from MR images is essential to computer‐aided diagnosis. However, due to the intrinsic heterogeneity of brain glioma, precise segmentation is very challenging, especially for tumor subregions. This article proposed a two‐stage cascaded method for brain tumor segmentation that considers the hierarchical structure of the target tumor subregions. The first stage aims to identify the whole tumor (WT) from the background area; and the second stage aims to achieve fine‐grained segmentation of the subregions, including enhanced tumor (ET) region and tumor core (TC) region. Both stages apply a deep neural network structure combining modified 3D U‐Net with a residual connection scheme to tumor region and subregion segmentation. Moreover, in the training phase, the 3D masks generation of subregions with potential incomplete connectivity are guided by the completely connected regions. Experiments were performed to evaluate the performance of the methods on both area and boundary accuracy. The average dice score of the WT, TC, and ET regions on BraTS 2020 dataset is 0.9168, 0.0.8992, 0.8489, and the Hausdorff distance is 6.021, 9.203, 12.171, respectively. The proposed method outperforms current works, especially in segmenting fine‐grained tumor subregions.

THE EffiCACY OF GAMMA KNIFE RADIOSURGERY FOR CYSTIC METASTASIS COMPARED WITH NON-CYSTIC METASTASIS

Abstract AIMS Between 20-40% of patients with cancer develop brain metastases (BMets), with metastasis representing the most common type of brain tumour. Cystic metastasis describes a rarer type of BMet characterised by oedematous collections. Stereotactic radiosurgery (SRS) is an effective and minimally invasive method for treating non-cystic BMets but controversy exists regarding its use in cystic BMets. The traditional view that cystic lesions are less responsive to SRS however is not fully evidenced. This investigation aims to elucidate the effectiveness of Gamma Knife (GK) radiosurgery in achieving local control of cystic BMets and enhancing survival versus GK radiosurgery for non-cystic BMets. METHOD Patients who had undergone fractionated GK for either a non-cystic or cystic BMet between 2018 and 2021 were identified. BMet volume on pre-GK MRI was calculated. Information was additionally collected on BMet location, maximum cyst diameter, if present, the patient’s primary tumour and its control and their performance status at the time of GK. The follow-up of patients is ongoing with survival being calculated using the Kaplan- Meier method and local progression through volumetric analysis of repeat MRI scans. RESULTS 57 patients with 79 cystic BMets were identified and 67 patients with non-cystic BMets. The most common primary tumour in both the non-cystic and the cystic BMets group was lung, comprising 30% and 23% respectively. The second most common tumour amongst non-cystic BMets was renal (12%) however in the cystic cohort it was breast (9%). The median tumour volume before treatment was 6.2cm3 in the non-cystic group and 12.5cm3 amongst cystic BMets. Median cyst size was 17.4 mm. Karnofsky Performance Status (KFS) was similar across both groups. CONCLUSION By comparing outcomes following GK for cystic and non-cystic metastasis, with the same primary tumours, this study can uncover the efficacy of fractionated GK for cystic lesions and aid the selection of treatments for these patients.

Immunotherapy for glioblastoma: current state, challenges, and future perspectives.

Glioblastoma (GBM) is an aggressive and lethal type of brain tumor in human adults. The standard of care offers minimal clinical benefit, and most GBM patients experience tumor recurrence after treatment. In recent years, significant advancements have been made in the development of novel immunotherapies or other therapeutic strategies that can overcome immunotherapy resistance in many advanced cancers. However, the benefit of immune-based treatments in GBM is limited because of the unique brain immune profiles, GBM cell heterogeneity, and immunosuppressive tumor microenvironment. In this review, we present a detailed overview of current immunotherapeutic strategies and discuss the challenges and potential molecular mechanisms underlying immunotherapy resistance in GBM. Furthermore, we provide an in-depth discussion regarding the strategies that can overcome immunotherapy resistance in GBM, which will likely require combination therapies.

The role of the Ki-67 labelling index as an independent prognostic factor in indonesian glioma patients.

Gliomas are the most common type of brain tumor. However, interpreting glioma morphology is subjective, and identifying mitosis can be challenging. This can impact the determination of the patient's tumor grade, therapy, and prognosis. In addition, the Ki-67 expression level, which reflects the tumor cells' ability to proliferate, is closely related to the patient's survival. This study aims to find a correlation between Ki-67 expression and the overall survival (OS) of glioma patients in the Indonesian population. Ninety-one glioma patients from Sardjito General Hospital were collected for formalin-fixed embedded paraffin (FFPE) samples, and the Ki-67 labeling index (LI) was calculated by determining the percentage of labeled nuclei per 1000 cells using a 40x objective lens in a randomized area (average method). The OS was calculated from the day of pathology diagnosis until death or the last follow-up (for censored cases). Kaplan-Meier survival analysis was used to analyze the OS. Individuals aged ≥60 with high-grade tumors, infratentorial gliomas, and a Ki-67 LI ≥10% had a shorter OS. The p-values associated with these factors were 0.001, 0.018, and 0.006, respectively. In multivariate analysis, age and tumor grade did not significantly correlate with OS. Glioma patients with a Ki-67 LI ≥10% have a significantly shorter OS than those with a lower Ki-67 LI, indicating that Ki-67 LI is an independent prognostic factor in Indonesian glioma patients.

DEVELOPING CEREBROSPINAL flUID METABOLOMIC BIOMARKERS FOR MINIMAL RESIDUAL DISEASE AND RELAPSE IN EPENDYMOMA AND MEDULLOBLASTOMA

Abstract AIMS Relapse rates of 30% and 50% in medulloblastoma and ependymoma lead to poor outcomes for paediatric brain tumours. Occurring usually within two years, relapses imply minimal residual disease (MRD) is present below the imaging detection threshold. Patient outcomes might be improved by diagnosing MRD using a sensitive, minimally invasive cerebrospinal fluid (CSF) liquid biopsy, as CSF is proximal to tumour. Metabolites arising from aberrant cancer metabolism may be biomarkers in CSF. METHOD With only 25µl CSF, extracted with 75µl methanol, liquid chromatography coupled with tandem high-resolution mass spectrometry (LC-MS/MS) could differentiate these paediatric brain tumours (n=47; day 14 post-surgery) from controls (n=49). RESULTS Fourteen metabolites were increased in abundance in tumours and four decreased compared to controls. These included amino acids and derivatives (n=8), metabolites in one carbon metabolism (n=1), carnitine cycle (n=2), aerobic glycolysis (n=2), purine catabolism (n=2), ascorbate degradation (n=1) and creatinine synthesis (n=2). From those, betaine/creatinine ratio gave an area under the curve (AUC) of 0.96 (excellent) in receiver operating curve analysis. Using a cut-off ratio of 0.1775 for discriminating brain tumours from controls, had sensitivity and specificity of 92% and 89%. Specifically identifying tumours, a ratio of betaine/threonate with cut-off 2.1514 discriminated ependymomas from controls (sensitivity/specificity 92%/91%). A ratio of malic acid/hypoxanthine with cut-off 0.04429 discriminated medulloblastomas from controls (sensitivity/specificity 100%/98%). Medulloblastomas (n=14) were largely similar to ependymomas (n=33); nevertheless, three metabolites met the criteria of corrected p&amp;lt;0.05. A ratio of glutarate semialdehyde/malic acid with cut-off 0.04243 discriminated ependymomas from medulloblastomas (sensitivity/specificity 79%/82%) in a good model (AUC 0.85). CONCLUSION This is the first report of CSF metabolites in ependymoma. Ratios between metabolites levels could be useful as biomarkers to detect brain tumours and distinguish brain tumour type specifically and sensitively. Further work to develop a liquid biopsy test for the detection of MRD is ongoing.

Precision Population Cancer Medicine in Brain Tumors: A Potential Roadmap to Improve Outcomes and Strategize the Steps to Bring Interdisciplinary Interventions.

Brain tumors, a significant health burden,rank as the second leading cause of cancer among adolescents and young adults and the eighth most common cancer in older adults. Despitetreatment advances, outcomesfor many brain tumor types,especiallyglioblastoma multiforme (GBM), remain poor. Precision population cancer medicine (PPCM) offerspromising avenues for improving outcomes in brain tumor management.This comprehensive reviewdelves intothe current landscape of brain tumor diagnosis and treatment,with a primary focus onthe potential of PPCM toenhancecare. The reviewexploresseveral key areas where PPCM approaches show promise. In genetics and molecular biology, the genetic heterogeneity of brain tumors poses challengesandopportunities for targeted therapies. Understanding genetic patterns canguidetreatment strategies and improve prognostication. Epigenetic modificationsarecrucialin brain tumor development and progression. Deoxyribonucleic acid(DNA) methylation patterns, particularly of theO6-methylguanine-DNA methyltransferase (MGMT) gene promoter, serve asessentialbiomarkers for treatment response and prognosis in GBM. Targeting epigenetic mechanisms could lead to novel therapeutic approaches. Non-invasive liquid biopsy techniques show potential for diagnosis, monitoring, and prognostication in brain tumors. Analysis of circulating tumor DNA and microRNAs may provide valuable information about tumor characteristics and treatment response. Advanced imaging techniques, including radiomics and radiogenomics, combined with artificial intelligence (AI) algorithms, are enhancing tumor detection, characterization, and treatment planning. These technologies can contribute to more personalized treatment approaches.In addition, emergingnanotherapeutic platforms, which involve the use of nanoparticles to deliver drugs directly to tumors,and theranostic approaches, which combine therapy and diagnostics in a single platform,offer new possibilities for targeted drug delivery and real-time treatment monitoring in brain tumors. The review also addresses socioeconomic and demographic factors influencing brain tumor incidence and outcomes. It highlightsthe starkdisparities in care access and survival rates among different racial and ethnic groups, emphasizing theurgentneed for PPCM strategies to address these inequities. Challenges in implementing PPCM for brain tumors include the blood-brain barrier, which limits drug delivery, and the need for more extensive clinical trials to validate new approaches. The authors stress the importance of interdisciplinary collaboration and data sharing to advance the field, making the audience feel united and part of a larger team. While PPCM holds great promise, the review emphasizes that it should complement, not replace, population-level interventions and standard-of-care treatments. The authors advocate for a balanced approach that leverages cutting-edge personalized strategies while ensuring broad access to effective treatments. In conclusion, PPCM represents a powerful tool in the fight against brain tumors, offering the potential for more targeted, effective, and less toxic treatments. However, realizing its full potential will require ongoing research, clinical validation, and policy interactionsto address disparities in care access.

Relationship between radiofrequency-electromagnetic radiation from cellular phones and brain tumor: meta-analyses using various proxies for RF-EMR exposure-outcome assessment

IntroductionThe authors conducted meta-analyses regarding the association between cellular and mobile phone use and brain tumor development by applying various radiofrequency-electromagnetic radiation (RF-EMR) exposure subcategories. With changing patterns of mobile phone use and rapidly developing Wireless Personal Area Network (WPAN) technology (such as Bluetooth), this study will provide insight into the importance of more precise exposure subcategories for RF-EMR.MethodsThe medical librarian searched MEDLINE (PubMed), EMBASE, and the Cochrane Library until 16 December 2020.ResultsIn these meta-analyses, 19 case-control studies and five cohort studies were included. Ipsilateral users reported a pooled odds ratio (OR) of 1.40 (95% CI 1.21–1.62) compared to non-regular users. Users with years of use over 10 years reported a pooled OR of 1.27 (95% CI 1.08–1.48). When stratified by each type of brain tumor, only meningioma (OR 1.20 (95% CI 1.04–1.39)), glioma (OR 1.45 (95% CI 1.16–1.82)), and malignant brain tumors (OR 1.93 (95% CI 1.55–2.39)) showed an increased OR with statistical significance for ipsilateral users. For users with years of use over 10 years, only glioma (OR 1.32 (95% CI 1.01–1.71)) showed an increased OR with statistical significance. When 11 studies with an OR with cumulative hours of use over 896 h were synthesized, the pooled OR was 1.59 (95% CI 1.25–2.02). When stratified by each type of brain tumor, glioma, meningioma, and acoustic neuroma reported the pooled OR of 1.66 (95% CI 1.13–2.44), 1.29 (95% CI 1.08–1.54), and 1.84 (95% CI 0.78–4.37), respectively. For each individual study that considered cumulative hours of use, the highest OR for glioma, meningioma, and acoustic neuroma was 2.89 (1.41–5.93) (both side use, > 896 h), 2.57 (1.02–6.44) (both side use, > 896 h), and 3.53 (1.59–7.82) (ipsilateral use, > 1640 h), respectively. For five cohort studies, the pooled risk ratios (RRs) for all CNS tumors, glioma, meningioma, and acoustic neuroma, were statistically equivocal, respectively. However, the point estimates for acoustic neuroma showed a rather increased pooled RR for ever-use (1.26) and over 10 years of use (1.61) compared to never-use, respectively.DiscussionIn this meta-analysis, as the exposure subcategory used became more concrete, the pooled ORs demonstrated higher values with statistical significance. Although the meta-analysis of cohort studies yielded statistically inconclusive pooled effect estimates, (i) as the number of studies included grows and (ii) as the applied exposure subcategories become more concrete, the pooled RRs could show a different aspect in future research. Additionally, future studies should thoroughly account for changing patterns in mobile phone use and the growing use of earphones or headphones with WPAN technology.