Profiling the molecular and clinical landscape of glioblastoma utilizing the Oncology Research Information Exchange Network brain cancer database.

Background: Glioblastoma exhibits aggressive growth and poor outcomes despite treatment, and its marked variability renders therapeutic design and prognostication challenging. The Oncology Research Information Exchange Network (ORIEN) database contains complementary clinical, genomic, and transcriptomic profiling of 206 glioblastoma patients, providing opportunities to identify novel associations between molecular features and clinical outcomes. Methods: Survival analyses were performed using the Logrank test, and clinical features were evaluated using Wilcoxon and chi-squared tests with q-values derived via Benjamini-Hochberg correction. Mutational analyses utilized sample-level enrichments from whole exome sequencing data, and statistical tests were performed using the one-sided Fisher Exact test with Benjamini-Hochberg correction. Transcriptomic analyses utilized a student's t-test with Benjamini-Hochberg correction. Expression fold changes were processed with Ingenuity Pathway Analysis to determine pathway-level alterations between groups. Results: Key findings include an association of MUC17, SYNE1, and TENM1 mutations with prolonged overall survival (OS); decreased OS associated with higher epithelial growth factor receptor (EGFR) mRNA expression, but not with EGFR amplification or mutation; a 14-transcript signature associated with OS > 2 years; and 2 transcripts associated with OS < 1 year. Conclusions: Herein, we report the first clinical, genomic, and transcriptomic analysis of ORIEN glioblastoma cases, incorporating sample reclassification under updated 2021 diagnostic criteria. These findings create multiple avenues for further investigation and reinforce the value of multi-institutional consortia such as ORIEN in deepening our knowledge of intractable diseases such as glioblastoma.

Genetically Distinct Oligosarcoma Arising from Oligodendroglioma: Systematic Review & Illustrative Case Example.

BACKGROUND: Oligosarcoma is a rare central nervous system (CNS) neoplasm that may arise following oligodendroglioma resection, which demonstrates a unique genetic profile and aggressive clinical phenotype. We present a systematic review and illustrative case example emphasizing the clinical and prognostic features of this unusual and unfavorable neuro-oncologic disease. METHODS: Systematic literature review and illustrative case report. RESULTS: A 41-year-old man who had undergone 2 neurosurgical resections for a World Health Organization grade II oligodendroglioma (Ki-67 = 5-10%, 1p/19q codeleted, IDH2 mutated), without adjuvant chemoradiation, presented with seizures seven years after resection. An extra-axial mass was identified adjacent to the resection cavity, in which gross total resection was achieved. Pathology confirmed World Health Organization grade IV oligosarcoma (Ki-67 = 20%). Adjuvant chemoradiation was initiated, with disease control observed over 6 months of follow-up. Seven publications met inclusion criteria. Oligosarcoma has been confirmed in 36 lesions, arising in 35 patients; 5 were primary oligosarcoma, while 31 occurred in the setting of prior resected oligodendroglioma or oligoastrocytoma. Features shared by these lesions include regain of H3K27me3 expression, 1p/19q codeletion, homozygous deletion of CDKN2A/B, loss of 6q, loss of NF1 and YAP1, and attenuation of CpG island methylator. Median survival after oligosarcoma diagnosis was 1.3 years (range, 0-5.2; n = 35). CONCLUSIONS: Oligosarcoma is a prognostically unfavorable CNS neoplasm with characteristic imaging and pathologic features, and a strong association with previously resected oligodendroglioma. Aggressive treatment is recommended, including gross total resection and adjuvant chemoradiation. Further study is required to define optimal treatment protocol for this CNS malignancy.

Physical Forces in Glioblastoma Migration: A Systematic Review.

The invasive capabilities of glioblastoma (GBM) define the cancer's aggressiveness, treatment resistance, and overall mortality. The tumor microenvironment influences the molecular behavior of cells, both epigenetically and genetically. Current forces being studied include properties of the extracellular matrix (ECM), such as stiffness and "sensing" capabilities. There is currently limited data on the physical forces in GBM-both relating to how they influence their environment and how their environment influences them. This review outlines the advances that have been made in the field. It is our hope that further investigation of the physical forces involved in GBM will highlight new therapeutic options and increase patient survival. A search of the PubMed database was conducted through to 23 March 2022 with the following search terms: (glioblastoma) AND (physical forces OR pressure OR shear forces OR compression OR tension OR torsion) AND (migration OR invasion). Our review yielded 11 external/applied/mechanical forces and 2 tumor microenvironment (TME) forces that affect the ability of GBM to locally migrate and invade. Both external forces and forces within the tumor microenvironment have been implicated in GBM migration, invasion, and treatment resistance. We endorse further research in this area to target the physical forces affecting the migration and invasion of GBM.

Polymorphous low-grade neuroepithelial tumor of the young: Rare tumor and review of the literature.

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a recently described low-grade neuroepithelial tumor with an infiltrative growth pattern and oligodendrocyte-like cells that are CD34 immunopositive. Correlating histology and results from molecular testing is critical to correctly diagnosing PLNTY, as its histologic appearance is similar to oligodendrogliomas and shares genetic abnormalities common to other low-grade epilepsy associated tumors (LEATs). In this case report, we describe a 31-year-old female with intractable epilepsy found to have a temporal mass and diagnosed with PLNTY after histopathologic and molecular testing. We describe the radiographic, histologic, and genetic features in relation to the epileptic and oncologic outcomes for this patient. Then, we compare these features and outcomes to other cases of PLNTY described in the literature.

Prognostic Implication of Patient Age in H3K27M-Mutant Midline Gliomas.

Introduction: Pediatric and adult H3K27M-mutant midline gliomas have variable clinical presentations, prognoses, and molecular backgrounds. In this study, we integrated data from published studies to investigate the differences between these two groups. Methods: PubMed and Web of Science were searched for potential data. Studies were included if they had available individual participant data on patients age of H3K27M-mutant midline gliomas. For time-to-event analyses, Kaplan-Meier analysis and Cox regression models were carried out; corresponding hazard ratios (HR) and 95% confidence intervals (CI) were computed to analyze the impact of age and clinical covariates on progression-free survival (PFS) and overall survival (OS). Results: We included 43 studies comprising 272 adults and 657 pediatric midline gliomas with H3K27M mutation for analyses. In adults, there was a male predilection whereas females were slightly more common than males in the pediatric group. Spinal cord tumors were more frequent in adults. The prevalence of H3.1 K27M mutation was significantly higher in the pediatric cohort. Compared to adult patients, pediatric H3K27M-mutant midline gliomas exhibited more aggressive features including higher rates of pathologic features of high-grade tumors and Ki67 proliferation index, and had a shorter PFS and OS. Genetically, ACVR1 mutations were more common whereas MGMT methylation, FGFR1, and NF1 mutations were less prevalent in the pediatric cohort. Conclusion: Pediatric H3K27M-mutant midline gliomas were demographically, clinically, and molecularly distinct from adult patients, highlighting an opportunity to refine the risk stratification for these neoplasms.

A systematic review of amino acid PET in assessing treatment response to temozolomide in glioma.

The response assessment in neuro-oncology (RANO) criteria have been the gold standard for monitoring treatment response in glioblastoma (GBM) and differentiating tumor progression from pseudoprogression. While the RANO criteria have played a key role in detecting early tumor progression, their ability to identify pseudoprogression is limited by post-treatment damage to the blood-brain barrier (BBB), which often leads to contrast enhancement on MRI and correlates poorly to tumor status. Amino acid positron emission tomography (AA PET) is a rapidly growing imaging modality in neuro-oncology. While contrast-enhanced MRI relies on leaky vascularity or a compromised BBB for delivery of contrast agents, amino acid tracers can cross the BBB, making AA PET particularly well-suited for monitoring treatment response and diagnosing pseudoprogression. The authors performed a systematic review of PubMed, MEDLINE, and Embase through December 2021 with the search terms "temozolomide" OR "Temodar," "glioma" OR "glioblastoma," "PET," and "amino acid." There were 19 studies meeting inclusion criteria. Thirteen studies utilized [18F]FET, five utilized [11C]MET, and one utilized both. All studies used static AA PET parameters to evaluate TMZ treatment in glioma patients, with nine using dynamic tracer parameters in addition. Throughout these studies, AA PET demonstrated utility in TMZ treatment monitoring and predicting patient survival.

OKN-007 Alters Protein Expression Profiles in High-Grade Gliomas: Mass Spectral Analysis of Blood Sera.

Current therapies for high-grade gliomas, particularly glioblastomas (GBM), do not extend patient survival beyond 16-22 months. OKN-007 (OKlahoma Nitrone 007), which is currently in phase II (multi-institutional) clinical trials for GBM patients, and has demonstrated efficacy in several rodent and human xenograft glioma models, shows some promise as an anti-glioma therapeutic, as it affects most aspects of tumorigenesis (tumor cell proliferation, angiogenesis, migration, and apoptosis). Combined with the chemotherapeutic agent temozolomide (TMZ), OKN-007 is even more effective by affecting chemo-resistant tumor cells. In this study, mass spectrometry (MS) methodology ESI-MS, mass peak analysis (Leave One Out Cross Validation (LOOCV) and tandem MS peptide sequence analyses), and bioinformatics analyses (Ingenuity® Pathway Analysis (IPA®)), were used to identify up- or down-regulated proteins in the blood sera of F98 glioma-bearing rats, that were either untreated or treated with OKN-007. Proteins of interest identified by tandem MS-MS that were decreased in sera from tumor-bearing rats that were either OKN-007-treated or untreated included ABCA2, ATP5B, CNTN2, ITGA3, KMT2D, MYCBP2, NOTCH3, and VCAN. Conversely, proteins of interest in tumor-bearing rats that were elevated following OKN-007 treatment included ABCA6, ADAMTS18, VWA8, MACF1, and LAMA5. These findings, in general, support our previous gene analysis, indicating that OKN-007 may be effective against the ECM. These findings also surmise that OKN-007 may be more effective against oligodendrogliomas, other brain tumors such as medulloblastoma, and possibly other types of cancers.

A tale of two multi-focal therapies for glioblastoma: An antibody targeting ELTD1 and nitrone-based OKN-007.

Glioblastoma (GBM) is the most common primary malignant brain tumour in adults. Despite a multimodal treatment response, survival for GBM patients remains between 12 and 15 months. Anti-ELTD1 antibody therapy is effective in decreasing tumour volumes and increasing animal survival in an orthotopic GBM xenograft. OKN-007 is a promising chemotherapeutic agent that is effective in various GBM animal models and is currently in two clinical trials. In this study, we sought to compare anti-ELTD1 and OKN-007 therapies, as single agents and combined, against bevacizumab, a commonly used therapeutic agent against GBM, in a human G55 xenograft mouse model. MRI was used to monitor tumour growth, and immunohistochemistry (IHC) was used to assess tumour markers for angiogenesis, cell migration and proliferation in the various treatment groups. OKN and anti-ELTD1 treatments significantly increased animal survival, reduced tumour volumes and normalized the vasculature. Additionally, anti-ELTD1 was also shown to significantly affect other pro-angiogenic factors such as Notch1 and VEGFR2. Unlike bevacizumab, anti-ELTD1 and OKN treatments did not induce a pro-migratory phenotype within the tumours. Anti-ELTD1 treatment was shown to be as effective as OKN therapy. Both OKN and anti-ELTD1 therapies show promise as potential single-agent multi-focal therapies for GBM patients.

H3K27M-mutant diffuse midline gliomas should be further molecularly stratified: an integrated analysis of 669 patients.

INTRODUCTION: H3K27M-mutated diffuse midline gliomas (H3-DMGs) are aggressive tumors with a fatal outcome. This study integrating individual patient data (IPD) from published studies aimed to investigate the prognostic impact of different genetic alterations on survival of these patients. METHODS: We accessed PubMed and Web of Science to search for relevant articles. Studies were included if they have available data of follow-up and additional molecular investigation of H3-DMGs. For survival analysis, Kaplan-Meier analysis and Cox regression models were utilized, and corresponding hazard ratios (HR) and 95% confidence intervals (CI) were computed to analyze the impact of genetic events on overall survival (OS). RESULT: We included 30 studies with 669 H3-DMGs. TP53 mutations were the most common second alteration among these neoplasms. In univariate Cox regression model, TP53 mutation was an indicator of shortened survival (HR 1.446; 95% CI 1.143-1.829) whereas ACVR1 (HR 0.712; 95% CI 0.518-0.976) and FGFR1 mutations (HR 0.408; 95% CI 0.208-0.799) conferred prolonged survival. In addition, ATRX loss was also associated with a better OS (HR 0.620; 95% CI 0.386-0.996). Adjusted for age, gender, and tumor location, the presence of TP53 mutations, the absence of ACVR1 or FGFR1 mutations remained significantly poor prognostic factors. CONCLUSIONS: We outlined the prognostic importance of additional genetic alterations in H3-DMGs and recommended that these neoplasms should be further molecularly segregated. This may aid neuro-oncologists in appropriate risk stratification.

ELTD1 as a multi-focal target for malignant gliomas: preclinical studies.

BACKGROUND: Glioblastoma (GBM) is the most aggressive malignant primary brain tumor in adults. These high-grade gliomas undergo unregulated vascular angiogenesis, migration and cell proliferation allowing the tumor cells to evade cell-cycle checkpoints and apoptotic pathways. The Epidermal growth factor, latrophilin, and seven transmembrane domain-containing 1 on chromosome 1 (ELTD1) is an angiogenic biomarker that is highly expressed in malignant gliomas. Novel treatments targeting ELTD1 with monovalent monoclonal (mmAb) and single chain variable fragment (scFv) antibodies were effective in increasing animal survival, decreasing tumor volume and normalizing the vasculature. Due to the success of our antibody treatments on angiogenesis, this study sought to determine if our anti-ELTD1 treatments affected other aspects of tumorigenesis (cell proliferation, migration, and apoptosis) in a G55 glioma xenograft preclinical mouse model. METHODS: Tumor tissue from untreated, mmAb and scFv anti-ELTD1 treated animals was used to quantify the positivity levels of human mitochondrial antibody, c-MET and Ki-67 for cellular proliferation, migratory markers CD44v6, TRPM8, and BMP2, and cleaved caspase 3 to assess apoptotic activity. RESULTS: This approach demonstrated that our anti-ELTD1 treatments directly affected and decreased the human tumor cells within the tumor region. Additionally, there was a significant decrease in both cellular proliferation and migration due to anti-ETLD1 therapy. Lastly, anti-ELTD1 treatments successfully increased apoptotic activity within the tumor region. CONCLUSION: Our data suggest that anti-ELTD1 therapies would be effective against malignant gliomas by having a multi-focal effect and targeting all four aspects of tumorigenesis.

A systematic review of the utility of amino acid PET in assessing treatment response to bevacizumab in recurrent high-grade glioma.

BACKGROUND: Currently, bevacizumab (BEV), an antiangiogenic agent, is used as an adjunctive therapy to re-irradiation and surgery in patients with recurrent high-grade gliomas (rHGG). BEV has shown to decrease enhancement on MRI, but it is often unclear if these changes are due to tumor response to BEV or treatment-induced changes in the blood brain barrier. Preliminary studies show that amino acid PET can aid in distinguishing these changes on MRI. METHODS: The authors performed a systematic review of PubMed and Embase through July 2020 with the search terms 'bevacizumab' or 'Avastin' and 'recurrent glioma' and 'PET,' yielding 38 papers, with 14 meeting inclusion criteria. RESULTS: Thirteen out of fourteen studies included in this review used static PET and three studies used dynamic PET to evaluate the use of BEV in rHGG. Six studies used the amino acid tracer [18F]FET, four studies used [11C]MET, and four studies used [18F]FDOPA. CONCLUSION: [18F]FET, [11C]MET, and [18F]FDOPA PET in combination with MRI have shown promising results for improving accuracy in diagnosing tumor recurrence, detecting early treatment failure, and distinguishing between tumor progression and treatment-induced changes in patients with rHGG treated with BEV.

Re-evaluating Biopsy for Recurrent Glioblastoma: A Position Statement by the Christopher Davidson Forum Investigators.

Patients with glioblastoma (GBM) need bold new approaches to their treatment, yet progress has been hindered by a relative inability to dynamically track treatment response, mechanisms of resistance, evolution of targetable mutations, and changes in mutational burden. We are writing on behalf of a multidisciplinary group of academic neuro-oncology professionals who met at the collaborative Christopher Davidson Forum at Washington University in St Louis in the fall of 2019. We propose a dramatic but necessary change to the routine management of patients with GBM to advance the field: to routinely biopsy recurrent GBM at the time of presumed recurrence. Data derived from these samples will identify true recurrence vs treatment effect, avoid treatments with little chance of success, enable clinical trial access, and aid in the scientific advancement of our understanding of GBM.

Physical confinement during cancer cell migration triggers therapeutic resistance and cancer stem cell-like behavior.

Metastasized cancer cells have an increased resistance to therapies leading to a drastic decrease in patient survival rates. However, our understanding of the cause for this enhanced resistance is lacking. In this study, we report that physically tight confinement during cancer cell migration triggers therapeutic resistance and induces cancer stem cell-like behavior including up-regulation in efflux proteins and in cancer stem cell related markers. Moreover, the re-localization of Yes-associated protein (YAP) to the cell nucleus indicated an elevated level of cytoskeletal tension. The increased cytoskeletal tension suggested that mechanical interactions between cancer cells and tight surroundings during metastasis is one of the factors that contributes to therapeutic resistance and acquisition of cancer stem cell (CSC) like features. With this system and supporting data, we are able to study cells with therapeutic resistance and CSC-like properties for the future purpose of developing new strategies for the treatment of metastatic cancer.

Anionic phospholipid expression as a molecular target in Listeria monocytogenes and Escherichia coli.

This study validates bacterial anionic phospholipids (APs) as a putative molecular target in a novel antibiotic treatment against the Gram-positive bacterium Listeria monocytogenes and the Gram-negative bacterium Escherichia coli. Bacterial AP expression was targeted with its associated protein-ligand partner, annexin A5 (ANXA5). This protein was functionalised with the covalent addition of the antibiotic ampicillin (AMP) and separately with the antibiotic moxifloxacin (MOX). Functionalised ANXA5 serves as a delivery vehicle, directing the antibiotic to bacterial AP expression. The results presented here suggest that this ANXA5-AMP bioconjugate participates in a positive feedback loop where APs, the target of the delivery vehicle ANXA5, are upregulated by the chemotherapeutic payload of the bioconjugate. Importantly, the ANXA5 delivery vehicle is non-toxic to bacterial cells by itself and neither is the ANXA5-antibiotic bioconjugate toxic to human vascular endothelial cells. As measured by the IC50, conjugation to ANXA5 resulted in increasing the antibiotic activity of AMP against L. monocytogenes and E. coli by more than 4 and 3 orders of magnitude, respectively, compared with free AMP, whilst the activity of MOX against L. monocytogenes is increased by 4 orders of magnitude. Given the conservation of AP expression in pathologies such as oncogenesis and other bacterial/viral/parasitic infections, we hypothesise that a therapeutic modality targeting AP expression may be a viable chemotherapeutic strategy in many infectious diseases.

Application of microfluidic devices for glioblastoma study: current status and future directions.

Glioblastoma (GBM) is one of the most malignant primary brain tumors. This neoplasm is the hardest to treat and has a bad prognosis. Because of the characteristics of genetic heterogeneity and frequent recurrence, a successful cure for the disease is unlikely. Increasing evidence has revealed that the GBM stem cell-like cells (GSCs) and microenvironment are key elements in GBM recurrence and treatment failure. To better understand the mechanisms underlying this disease and to develop more effective therapeutic strategies for treatment, suitable approaches, techniques, and model systems closely mimicking real GBM conditions are required. Microfluidic devices, a model system mimicking the in vivo brain microenvironment, provide a very useful tool to analyze GBM cell behavior, their correlation with tumor malignancy, and the efficacy of multiple drug treatment. This paper reviews the applications of microfluidic devices in GBM research and summarizes progress and perspectives in this field.

NRG/RTOG 1122: A phase 2, double-blinded, placebo-controlled study of bevacizumab with and without trebananib in patients with recurrent glioblastoma or gliosarcoma.

BACKGROUND: Targeting vascular endothelial growth factor (VEGF) alone does not improve overall survival (OS) in recurrent glioblastoma (rGBM). The angiopoiein (Ang)-TIE2 system may play a role in tumor survival under VEGF inhibition. We conducted a phase 2, double-blinded, placebo-controlled trial of bevacizumab plus trebananib (a novel Fc fusion protein that sequesters Ang1/Ang2) over bevacizumab alone in rGBM. METHODS: Patients ≥18 years of age with a Karnofsky performance status ≥70 and GBM or variants in first or second relapse were randomized to bevacizumab 10 mg/kg every 2 weeks plus trebananib 15 mg/kg every week or bevacizumab plus placebo. The primary endpoint was 6-month progression-free survival (PFS). RESULTS: After an initial 6-patient lead-in cohort confirmed the safety of combining bevacizumab and trebananib, 115 eligible patients were randomized to the control (n = 58) or experimental treatment (n = 57). In the control arm, 6-month PFS was 41.1%, median survival time was 11.5 months (95% CI, 8.4-14.2 months), median PFS was 4.8 months (95% CI, 3.8-7.1 months), and radiographic response (RR) was 5.9%. In the experimental arm, 6-month PFS was 22.6%, median survival time was 7.5 months (95% CI, 6.8-10.1 months), median PFS was 4.2 months (95% CI, 3.7-5.6 months), and RR was 4.2%. The rate of severe toxicities was not significantly different between arms. CONCLUSION: The combination of bevacizumab and trebananib was well tolerated but did not significantly improve 6-month PFS rate, PFS, or OS for patients with rGBM over bevacizumab alone. The shorter PFS in the experimental arm with a hazard ratio of 1.51 (P = .04) suggests that the addition of trebananib to bevacizumab is detrimental.

Assessment of an scFv Antibody Fragment Against ELTD1 in a G55 Glioblastoma Xenograft Model.

Glioblastoma (GBM), the most common primary brain tumor found in adults, is extremely aggressive. These high-grade gliomas, which are very diffuse, highly vascular, and invasive, undergo unregulated vascular angiogenesis. Despite available treatments, the median survival for patients is dismal. ELTD1 (EGF, latrophilin, and 7 transmembrane domain containing protein 1) is an angiogenic biomarker highly expressed in human high-grade gliomas. Recent studies have demonstrated that the blood-brain barrier, as well as the blood-tumor barrier, is not equally disrupted in GBM patients. This study therefore aimed to optimize an antibody treatment against ELTD1 using a smaller scFv fragment of a monoclonal antibody that binds against the external region of ELTD1 in a G55 glioma xenograft glioma preclinical model. Morphological magnetic resonance imaging (MRI) was used to determine tumor volumes and quantify perfusion rates. We also assessed percent survival following tumor postdetection. Tumor tissue was also assessed to confirm and quantify the presence of the ELTD1 scFv molecular targeted MRI probe, as well as microvessel density and Notch1 levels. In addition, we used molecular-targeted MRI to localize our antibodies in vivo. This approach showed that our scFv antibody attached-molecular MRI probe was effective in targeting and localizing diffuse tumor regions. Through this analysis, we determined that our anti-ELTD1 scFv antibody treatments were successful in increasing survival, decreasing tumor volumes, and normalizing vascular perfusion and Notch1 levels within tumor regions. This study demonstrates that our scFv fragment antibody against ELTD1 may be useful and potential antiangiogenic treatments against GBM.

Pure Apraxia of Speech After Resection Based in the Posterior Middle Frontal Gyrus.

BACKGROUND AND IMPORTANCE: Apraxia of speech is a disorder of articulatory coordination and planning in speech sound production. Its diagnosis is based on deficits in articulation, prosody, and fluency. It is often described concurrent with aphasia or dysarthria, while pure apraxia of speech is a rare entity. CLINICAL PRESENTATION: A right-handed man underwent focal surgical resection of a recurrent grade III astrocytoma in the left hemisphere dorsal premotor cortex located in the posterior middle frontal gyrus. After the procedure, he experienced significant long-term speech production difficulties. A battery of standard and custom language and articulatory assessments were administered, revealing intact comprehension and naming abilities, and preserved strength in orofacial articulators, but considerable deficits in articulatory coordination, fluency, and prosody-consistent with diagnosis of pure apraxia of speech. Tractography and resection volumes compared with publicly available imaging data from the Human Connectome Project suggest possible overlap with area 55b, an under-recognized language area in the dorsal premotor cortex and has white matter connectivity with the superior longitudinal fasciculus. CONCLUSION: The case reported here details a rare clinical entity, pure apraxia of speech resulting from resection of posterior middle frontal gyrus. While not a classical language area, emerging literature supports the role of this area in the production of fluent speech, and has implications for surgical planning and the general neurobiology of language.

Optimized monoclonal antibody treatment against ELTD1 for GBM in a G55 xenograft mouse model.

Glioblastoma is an aggressive brain tumour found in adults, and the therapeutic approaches available have not significantly increased patient survival. Recently, we discovered that ELTD1, an angiogenic biomarker, is highly expressed in human gliomas. Polyclonal anti-ELTD1 treatments were effective in glioma pre-clinical models, however, pAb binding is potentially promiscuous. Therefore, the aim of this study was to determine the effects of an optimized monoclonal anti-ELTD1 treatment in G55 xenograft glioma models. MRI was used to assess the effects of the treatments on animal survival, tumour volumes, perfusion rates and binding specificity. Immunohistochemistry and histology were conducted to confirm and characterize microvessel density and Notch1 levels, and to locate the molecular probes. RNA-sequencing was used to analyse the effects of the mAb treatment. Our monoclonal anti-ELTD1 treatment significantly increased animal survival, reduced tumour volumes, normalized the vasculature and showed higher binding specificity within the tumour compared with both control- and polyclonal-treated mice. Notch1 positivity staining and RNA-seq results suggested that ELTD1 has the ability to interact with and interrupt Notch1 signalling. Although little is known about ELTD1, particularly about its ligand and pathways, our data suggest that our monoclonal anti-ELTD1 antibody is a promising anti-angiogenic therapeutic in glioblastomas.

Glioblastoma Multiforme heterogeneity profiling with solid-state micropores.

Glioblastoma multiforme (GBM) is the most common and lethal type of brain cancer. It is characterized by widespread heterogeneity at the cellular and molecular levels. The detection of this heterogeneity is valuable for accurate diagnosis. Herein, solid-state 20 µm diameter micropore made in thin suspended silicon dioxide membrane is used as cell sensor device. The device relies on a cell's mechano-physical properties as an indicator to differentiate between the subtypes of GBM. A library of GBM cell lines (U251, U87, D54 EGFRviii, and G55) was created by measuring the differences in cell's micropore translocation properties from their distinct electrical profiles. Each GBM subtype has distinct phenotype and this was delineated in their cell translocation behaviors. The library was used to distinguish cells from samples of brain tumor patients. The micropore device accurately profiled GBM patient samples for cell subtypes by comparing data with the GBM library. The micropore approach is simple, can be implemented at low cost and can be used in the clinical setups and operation theaters to detect and identify GBM subtypes from patient samples.