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Introduction Brain tumors cause morbidity and mortality in part through peritumoral brain edema. The current main treatment for peritumoral brain edema are corticosteroids. Due to the increased recognition of their side-effect profile, there is growing interest in finding alternatives to steroids but there is little formal study of animal models of peritumoral brain edema. This study aims to summarize the available literature. Methods A systematic search was undertaken of 5 literature databases (Medline, Embase, CINAHL, PubMed and the Cochrane Library). The generic strategy was to search for various terms associated with “brain tumors”, “brain edema” and “animal models”. Results We identified 603 reports, of which 112 were identified as relevant for full text analysis that studied 114 peritumoral brain edema animal models. We found significant heterogeneity in the species and strain of tumor-bearing animals, tumor implantation method and edema assessment. Most models did not produce appreciable brain edema and did not test for observable manifestations thereof. Conclusion No animal model currently exists that enable the investigation of novel candidates for the treatment of peritumoral brain edema. With current interest in alternative treatments for peritumoral brain edema, there is an unmet need for clinically relevant animal models.

BACKGROUND: Extracellular vesicles (EVs) play an important role in cell–cell communication, and tumor-derived EVs circulating in patient blood can serve as biomarkers. Here, we investigated the potential role of plasma EVs in meningioma patients for tumor detection and determined whether EVs secreted by meningioma cells reflect epigenetic, genomic, and proteomic alterations of original tumors. METHODS: EV concentrations were quantified in patient plasma (n = 46). Short-term meningioma cultures were established (n = 26) and secreted EVs were isolated. Methylation and copy number profiling was performed using 850k arrays, and mutations were identified by targeted gene panel sequencing. Differential quantitative mass spectrometry was employed for proteomic analysis. RESULTS: Levels of circulating EVs were elevated in meningioma patients compared to healthy individuals, and the plasma EV concentration correlated with malignancy grade and extent of peritumoral edema. Postoperatively, EV counts dropped to normal levels, and the magnitude of the postoperative decrease was associated with extent of tumor resection. Methylation profiling of EV-DNA allowed correct tumor classification as meningioma in all investigated cases, and accurate methylation subclass assignment in almost all cases. Copy number variations present in tumors, as well as tumor-specific mutations were faithfully reflected in meningioma EV-DNA. Proteomic EV profiling did not permit original tumor identification but revealed tumor-associated proteins that could potentially be utilized to enrich meningioma EVs from biofluids. CONCLUSIONS: Elevated EV levels in meningioma patient plasma could aid in tumor diagnosis and assessment of treatment response. Meningioma EV-DNA mirrors genetic and epigenetic tumor alterations and facilitates molecular tumor classification.

Central nervous system (CNS) tumor patients commonly undergo multimodality treatment in the course of their disease. Adverse effects and complications from these interventions have not been systematically studied, but pose significant challenges in clinical practice and impact function and quality of life, especially in the management of long-term brain tumor survivors. Here, the European Association of Neuro-Oncology (EANO) has developed recommendations to prevent, diagnose, and manage adverse effects and complications in the adult primary brain CNS tumor (except lymphomas) patient population with a specific focus on surgery, radiotherapy, and pharmacotherapy. Specifically, we also provide recommendations for dose adaptations, interruptions, and reexposure for pharmacotherapy that may serve as a reference for the management of standard of care in clinical trials. We also summarize which interventions are unnecessary, inactive or contraindicated. This consensus paper should serve as a reference for the conduct of standard therapy within and outside of clinical trials.

Background Preclinical data suggest some cannabinoids may exert antitumour effects against glioblastoma (GBM). Safety and preliminary efficacy of nabiximols oromucosal cannabinoid spray plus dose-intense temozolomide (DIT) was evaluated in patients with first recurrence of GBM. Methods Part 1 was open-label and Part 2 was randomised, double-blind, and placebo-controlled. Both required individualised dose escalation. Patients received nabiximols (Part 1, n = 6; Part 2, n = 12) or placebo (Part 2 only, n = 9); maximum of 12 sprays/day with DIT for up to 12 months. Safety, efficacy, and temozolomide (TMZ) pharmacokinetics (PK) were monitored. Results The most common treatment-emergent adverse events (TEAEs; both parts) were vomiting, dizziness, fatigue, nausea and headache. Most patients experienced TEAEs that were grade 2 or 3 (CTCAE). In Part 2, 33% of both nabiximols- and placebo-treated patients were progression-free at 6 months. Survival at 1 year was 83% for nabiximols- and 44% for placebo-treated patients (p = 0.042), although two patients died within the first 40 days of enrolment in the placebo arm. There were no apparent effects of nabiximols on TMZ PK. Conclusions With personalised dosing, nabiximols had acceptable safety and tolerability with no drug–drug interaction identified. The observed survival differences support further exploration in an adequately powered randomised controlled trial. Clinical trial registration ClinicalTrials.gov: Part 1– NCT01812603; Part 2– NCT01812616.

MicroRNAs play an important role in the regulation of mRNA translation and have therapeutic potential in cancer and other diseases. To profile the landscape of microRNAs with significant cytotoxicity in the context of glioblastoma (GBM), we performed a high-throughput screen in adult and pediatric GBM cells using a synthetic oligonucleotide library representing all known human microRNAs. Bioinformatics analysis was used to refine this list and the top seven microRNAs were validated in a larger panel of GBM cells using state-of-the-art in vitro assays. The cytotoxic effect of our most relevant candidate was assessed in a preclinical model. Our screen identified ~100 significantly cytotoxic microRNAs with 70% concordance between cell lines. MicroRNA-1300 (miR-1300) was the most potent and robust candidate. We observed a striking binucleated phenotype in miR-1300 transfected cells due to cytokinesis failure followed by apoptosis. This was also observed in two stem-like patient-derived cultures. We identified the physiological role of miR-1300 as a regulator of endomitosis in megakaryocyte differentiation where blockade of cytokinesis is an essential step. In GBM cells, where miR-1300 is normally not expressed, the oncogene Epithelial Cell Transforming 2 (ECT2) was validated as a direct key target. ECT2 siRNA phenocopied the effects of miR-1300, and ECT2 overexpression led to rescue of miR-1300 induced binucleation. We showed that ectopic expression of miR-1300 led to decreased tumor growth in an orthotopic GBM model. Our screen provides a resource for the neuro-oncology community and identified miR-1300 as a novel regulator of endomitosis with translatable potential for therapeutic application.

Background Gliomas are associated with significant healthcare burden, yet reports of costs are scarce. While many costs are unavoidable there may be treatable symptoms contributing to higher costs. We describe healthcare and societal costs in glioma patients at high risk for depression and their family caregivers, and explore relationships between costs and treatable symptoms. Methods Data from a multicenter randomized trial on effects of internet-based therapy for depressive symptoms were used (NTR3223). Costs of self-reported healthcare utilization, medication use, and productivity loss were calculated for patients and caregivers separately. We used generalized linear regression models to predict costs with depressive symptoms, fatigue, cognitive complaints, tumor grade (low-/high-grade), disease status (stable or active/progression), and intervention (use/non-use) as predictors. Results Multiple assessments from baseline through 12 months from 91 glioma patients and 46 caregivers were used. Mean overall costs per year were M = €20,587.53 (sd = €30,910.53) for patients and M = €5,581.49 (sd = €13,102.82) for caregivers. In patients, higher healthcare utilization costs were associated with more depressive symptoms; higher medication costs were associated with active/progressive disease. In caregivers, higher overall costs were linked with increased caregiver fatigue, cognitive complaints, and lower patient tumor grade. Higher healthcare utilization costs were related to more cognitive complaints and lower tumor grade. More productivity loss costs were associated with increased fatigue (all P Conclusions There are substantial healthcare and societal costs for glioma patients and caregivers. Associations between costs and treatable psychological symptoms indicate that possibly, adequate support could decrease costs. Trial registration Netherlands Trial Register NTR3223.

Background Detailed prevalence estimates of BRAFV600 mutations and BRAF inhibitor (BRAFi) treatment responses in V600-mutant glioma will inform trial development. Methods Our systematic review analyzed overall prevalence of BRAFV600 mutations in glioma and BRAFi treatment response. Results Based on 13 682 patients in 182 publications, the prevalence of BRAFV600 in epithelioid glioblastoma (eGBM) was 69% [95% CI: 45–89%]; pleomorphic xanthoastrocytoma (PXA): 56% [48–64%] anaplastic pleomorphic xanthoastrocytoma (aPXA): 38% [23–54%], ganglioglioma (GG): 40% [33–46%], and anaplastic ganglioglioma (aGG): 46% [18–76%]. Prevalence in astroblastoma was 24% [8–43%], desmoplastic infantile astrocytoma (DIA): 16% [0–57%], subependymal giant cell astrocytoma (SEGA): 8% [0–37%], dysembryoplastic neuroepithelial tumor (DNET): 3% [0–11%], diffuse astrocytoma (DA): 3% [0–9%], and pilocytic astrocytoma (PA): 3% [2–5%]. We reviewed 394 V600-mutant gliomas treated with BRAFi from 130 publications. One hundred and twenty-nine pediatric low-grade gliomas showed 4 (3.1%) complete response (CR); 53 (41.1%) partial response (PR); 64 (49.6%) stable disease (SD) and 8 (6.2%) progressive disease (PD). 25 pediatric high-grade gliomas showed CR; PR; SD; PD in 4 (16.0%); 10 (40.0%), 4 (16.0%); and 7 (28.0%) respectively. Thirty-nine adult low-grade gliomas showed CR; PR; SD; PD of 4 (10.3%); 17 (43.6%); 16 (41.0%) and 2 (5.1%) respectively. Ninety-seven adult high-grade gliomas showed CR; PR; SD; PD of 6 (6.2%); 31 (32.0%); 27 (27.8%); and 33 (34.0%) respectively. Conclusions BRAFV600 prevalence is highest in eGBM, PXA, aPXA, GG, aGG, and lower in astroblastoma, DIA, SEGA, DNET, DA, and PA. Our data provide the rationale for adjuvant clinical trials of BRAFi in V600-mutant glioma.

Background Glioblastoma multiforme (GBM) is the most common high-grade malignant brain tumour in adults and arises from the glial cells in the brain. The prognosis of treated GBM remains very poor with 5-year survival rates of 5%, a figure which has not improved over the last few decades. Currently, there is a modest 14-month overall median survival in patients undergoing maximum safe resection plus adjuvant chemoradiotherapy. HOX gene dysregulation is now a widely recognised feature of many malignancies. Methods In this study we have focused on HOX gene dysregulation in GBM as a potential therapeutic target in a disease with high unmet need. Results We show significant dysregulation of these developmentally crucial genes and specifically that HOX genes A9, A10, C4 and D9 are strong candidates for biomarkers and treatment targets for GBM and GBM cancer stem cells. We evaluated a next generation therapeutic peptide, HTL-001, capable of targeting HOX gene over-expression in GBM by disrupting the interaction between HOX proteins and their co-factor, PBX. HTL-001 induced both caspase-dependent and –independent apoptosis in GBM cell lines. Conclusion In vivo biodistribution studies confirmed that the peptide was able to cross the blood brain barrier. Systemic delivery of HTL-001 resulted in improved control of subcutaneous murine and human xenograft tumours and improved survival in a murine orthotopic model.

Summary Glioblastoma (GBM) is an aggressive cancer with a very poor prognosis. Generally viewed as weakly immunogenic, GBM responds poorly to current immunotherapies. To understand this problem more clearly we used a combination of natural killer (NK) cell functional assays together with gene and protein expression profiling to define the NK cell response to GBM and explore immunosuppression in the GBM microenvironment. In addition, we used transcriptome data from patient cohorts to classify GBM according to immunological profiles. We show that glioma stem‐like cells, a source of post‐treatment tumour recurrence, express multiple immunomodulatory cell surface molecules and are targeted in preference to normal neural progenitor cells by natural killer (NK) cells ex vivo. In contrast, GBM‐infiltrating NK cells express reduced levels of activation receptors within the tumour microenvironment, with hallmarks of transforming growth factor (TGF)‐β‐mediated inhibition. This NK cell inhibition is accompanied by expression of multiple immune checkpoint molecules on T cells. Single‐cell transcriptomics demonstrated that both tumour and haematopoietic‐derived cells in GBM express multiple, diverse mediators of immune evasion. Despite this, immunome analysis across a patient cohort identifies a spectrum of immunological activity in GBM, with active immunity marked by co‐expression of immune effector molecules and feedback inhibitory mechanisms. Our data show that GBM is recognized by the immune system but that anti‐tumour immunity is restrained by multiple immunosuppressive pathways, some of which operate in the healthy brain. The presence of immune activity in a subset of patients suggests that these patients will more probably benefit from combination immunotherapies directed against multiple immunosuppressive pathways., Our manuscript challenges the current paradigm that Glioblastoma (GBM) is a poor candidate for immunotherapy, therefore impacting on clinical approaches. We identify NK cells as a target for immunosuppression in GBM, with multiple suppressive pathways within GBM human tumours. We also identify a group of GBM patients with higher immunological activity, who will benefit from immunotherapies that target these immunosuppressive pathways.

The authors wish to make the following corrections to this paper [1] [...]

BACKGROUND Glioma diagnosis can be devastating, and results in a wide range of symptoms. Relatively little is known about the long-term challenges these symptoms pose on HRQOL. The aim of this review is to identify the long-term HRQOL issues reported at least two years following diagnosis of glioma. METHOD Systematic literature searches were carried out using Medline, EMBASE, CINAHL, PsycINFO, and Web of Science Core Collection. Searches were designed to identify a range of reported HRQOL aspects defined as physical, mental or social issues, in adult WHO grade II or III patients. To capture the full extent of patients’ experience, studies of any design reporting on primary data where patients had at least two years follow-up from diagnosis were included. WHO grade I and grade IV tumours were excluded due to their different prognoses and the expected nature of their disease trajectories. Narrative synthesis was used to collate findings. RESULTS The search returned 8438 articles. 477 titles remained after title and abstract screening, with seventeen full text articles included in the final analysis. The majority of studies used quantitative methods, with only two articles reporting qualitative or mixed methodology. Articles were predominantly cross-sectional studies (n = 9), along with cohort studies (n = 3), clinical trials (n = 3) and pilot studies (n = 2). Results indicated that patients reported a variety of issues influencing their HRQOL, with emotional/psychological/cognitive changes the most frequently reported. Physical complaints included problems with fatigue, seizures and maintaining daily activity. Social challenges included strained social relationships and issues managing finances. Patient coping strategies were found to significantly influence wellbeing and subsequent HRQOL. CONCLUSION Glioma patients’ long-term HRQOL and daily functioning can be impacted by their physical, mental and social wellbeing. Findings from this review lay the groundwork for efforts to improve patient long-term HRQOL.

Anti-1-amino-3-18fluorine-fluorocyclobutane-1-carboxylic acid (18F-fluciclovine) positron emission tomography (PET) shows preferential glioma uptake but there is little data on how uptake correlates with post-contrast T1-weighted (Gd-T1) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) activity during adjuvant treatment. This pilot study aimed to compare 18F-fluciclovine PET, DCE-MRI and Gd-T1 in patients undergoing chemoradiotherapy for glioblastoma (GBM), and in a parallel pre-clinical GBM model, to investigate correlation between 18F-fluciclovine uptake, MRI findings, and tumour biology. 18F-fluciclovine-PET-computed tomography (PET-CT) and MRI including DCE-MRI were acquired before, during and after adjuvant chemoradiotherapy (60 Gy in 30 fractions with temozolomide) in GBM patients. MRI volumes were manually contoured; PET volumes were defined using semi-automatic thresholding. The similarity of the PET and DCE-MRI volumes outside the Gd-T1 volume boundary was measured using the Dice similarity coefficient (DSC). CT-2A tumour-bearing mice underwent MRI and 18F-fluciclovine PET-CT. Post-mortem mice brains underwent immunohistochemistry staining for ASCT2 (amino acid transporter), nestin (stemness) and Ki-67 (proliferation) to assess for biologically active tumour. 6 patients were recruited (GBM 1–6) and grouped according to overall survival (OS)—short survival (GBM-SS, median OS 249 days) and long survival (GBM-LS, median 903 days). For GBM-SS, PET tumour volumes were greater than DCE-MRI, in turn greater than Gd-T1. For GBM-LS, Gd-T1 and DCE-MRI were greater than PET. Tumour-specific 18F-fluciclovine uptake on pre-clinical PET-CT corresponded to immunostaining for Ki-67, nestin and ASCT2. Results suggest volumes of 18F-fluciclovine-PET activity beyond that depicted by DCE-MRI and Gd-T1 are associated with poorer prognosis in patients undergoing chemoradiotherapy for GBM. The pre-clinical model confirmed 18F-fluciclovine uptake reflected biologically active tumour.

The evolutionary processes that drive universal therapeutic resistance in adult patients with diffuse glioma remain unclear1,2. Here we analysed temporally separated DNA-sequencing data and matched clinical annotation from 222 adult patients with glioma. By analysing mutations and copy numbers across the three major subtypes of diffuse glioma, we found that driver genes detected at the initial stage of disease were retained at recurrence, whereas there was little evidence of recurrence-specific gene alterations. Treatment with alkylating agents resulted in a hypermutator phenotype at different rates across the glioma subtypes, and hypermutation was not associated with differences in overall survival. Acquired aneuploidy was frequently detected in recurrent gliomas and was characterized by IDH mutation but without co-deletion of chromosome arms 1p/19q, and further converged with acquired alterations in the cell cycle and poor outcomes. The clonal architecture of each tumour remained similar over time, but the presence of subclonal selection was associated with decreased survival. Finally, there were no differences in the levels of immunoediting between initial and recurrent gliomas. Collectively, our results suggest that the strongest selective pressures occur during early glioma development and that current therapies shape this evolution in a largely stochastic manner.

Glioblastomas are the most common form of malignant primary brain tumor and an important cause of morbidity and mortality. In recent years there have been important advances in understanding the molecular pathogenesis and biology of these tumors, but this has not translated into significantly improved outcomes for patients. In this consensus review from the Society for Neuro-Oncology (SNO) and the European Association of Neuro-Oncology (EANO), the current management of isocitrate dehydrogenase wildtype (IDHwt) glioblastomas will be discussed. In addition, novel therapies such as targeted molecular therapies, agents targeting DNA damage response and metabolism, immunotherapies, and viral therapies will be reviewed, as well as the current challenges and future directions for research.

The oncogene epidermal growth factor receptor variant III (EGFRvIII) is frequently expressed in glioblastomas (GBM) but its impact on therapy response is still under controversial debate. Here we wanted to test if EGFRvIII influences the sensitivity towards the alkylating agent temozolomide (TMZ). Therefore, we retrospectively analyzed the survival of 336 GBM patients, demonstrating that under standard treatment, which includes TMZ, EGFRvIII expression is associated with prolonged survival, but only in patients with O6-methylguanine-DNA methyltransferase (MGMT) promoter methylated tumors. Using isogenic GBM cell lines with endogenous EGFRvIII expression we could demonstrate that EGFRvIII increases TMZ sensitivity and results in enhanced numbers of DNA double-strand breaks and a pronounced S/G2-phase arrest after TMZ treatment. We observed a higher expression of DNA mismatch repair (MMR) proteins in EGFRvIII+ cells and patient tumor samples, which was most pronounced for MSH2 and MSH6. EGFRvIII-specific knockdown reduced MMR protein expression thereby increasing TMZ resistance. Subsequent functional kinome profiling revealed an increased activation of p38- and ERK1/2-dependent signaling in EGFRvIII expressing cells, which regulates MMR protein expression downstream of EGFRvIII. In summary, our results demonstrate that the oncoprotein EGFRvIII sensitizes a fraction of GBM to current standard of care treatment through the upregulation of DNA MMR.

The overall survival for patients with primary glioblastoma is very poor. Glioblastoma contains a subpopulation of glioma stem cells (GSC) that are responsible for tumour initiation, treatment resistance and recurrence. PPARα is a transcription factor involved in the control of lipid, carbohydrate and amino acid metabolism. We have recently shown that PPARα gene and protein expression is increased in glioblastoma and has independent clinical prognostic significance in multivariate analyses. In this work, we report that PPARα is overexpressed in GSC compared to foetal neural stem cells. To investigate the role of PPARα in GSC, we knocked down its expression using lentiviral transduction with short hairpin RNA (shRNA). Transduced GSC were tagged with luciferase and stereotactically xenografted into the striatum of NOD‐SCID mice. Bioluminescent and magnetic resonance imaging showed that knockdown (KD) of PPARα reduced the tumourigenicity of GSC in vivo. PPARα‐expressing control GSC xenografts formed invasive histological phenocopies of human glioblastoma, whereas PPARα KD GSC xenografts failed to establish viable intracranial tumours. PPARα KD GSC showed significantly reduced proliferative capacity and clonogenic potential in vitro with an increase in cellular senescence. In addition, PPARα KD resulted in significant downregulation of the stem cell factors c‐Myc, nestin and SOX2. This was accompanied by downregulation of the PPARα‐target genes and key regulators of fatty acid oxygenation ACOX1 and CPT1A, with no compensatory increase in glycolytic flux. These data establish the aberrant overexpression of PPARα in GSC and demonstrate that this expression functions as an important regulator of tumourigenesis, linking self‐renewal and the malignant phenotype in this aggressive cancer stem cell subpopulation. We conclude that targeting GSC PPARα expression may be a therapeutically beneficial strategy with translational potential as an adjuvant treatment. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Magnetic resonance imaging (MRI) offers superior soft-tissue contrast as compared with computed tomography (CT), which is conventionally used for radiation therapy treatment planning (RTP) and patient positioning verification, resulting in improved target definition. The 2 modalities are co-registered for RTP; however, this introduces a systematic error. Implementing an MRI-only radiation therapy workflow would be advantageous because this error would be eliminated, the patient pathway simplified, and patient dose reduced. Unlike CT, in MRI there is no direct relationship between signal intensity and electron density; however, various methodologies for MRI-only RTP have been reported. A systematic review of these methods was undertaken. The PRISMA guidelines were followed. Embase and Medline databases were searched (1996 to March, 2017) for studies that generated synthetic CT scans (sCT)s for MRI-only radiation therapy. Sixty-one articles met the inclusion criteria. This review showed that MRI-only RTP techniques could be grouped into 3 categories: (1) bulk density override; (2) atlas-based; and (3) voxel-based techniques, which all produce an sCT scan from MR images. Bulk density override techniques either used a single homogeneous or multiple tissue override. The former produced large dosimetric errors (>2%) in some cases and the latter frequently required manual bone contouring. Atlas-based techniques used both single and multiple atlases and included methods incorporating pattern recognition techniques. Clinically acceptable sCTs were reported, but atypical anatomy led to erroneous results in some cases. Voxel-based techniques included methods using routine and specialized MRI sequences, namely ultra-short echo time imaging. High-quality sCTs were produced; however, use of multiple sequences led to long scanning times increasing the chances of patient movement. Using nonroutine sequences would currently be problematic in most radiation therapy centers. Atlas-based and voxel-based techniques were found to be the most clinically useful methods, with some studies reporting dosimetric differences of

BACKGROUND A primary brain tumour (PrBT) diagnosis can be devastating, and results in a wide range of symptoms. Relatively little is known about the long-term challenges these symptoms pose on HRQOL. The aim of this review is to identify the long-term HRQOL issues reported at least two years following diagnosis of a PrBT. MATERIAL AND METHODS Systematic literature searches were carried out using Medline, EMBASE, CINAHL, PsycINFO and Web of Science Core Collection. Searches were designed to identify a range of reported HRQOL aspects defined as physical, mental or social issues, in adult WHO grade II or III patients. To capture the full extent of patients’ experience, studies of any design reporting on primary data where patients had at least two years follow-up from diagnosis were included. WHO grade I and grade IV tumours were excluded due to their different prognoses and the expected nature of their disease trajectories. Quality assessment was conducted using the Mixed Methods Appraisal Tool (MMAT). Narrative synthesis was used to collate findings. RESULTS The search returned 8438 articles. 477 titles remained after title and abstract screening, with eighteen full text articles included in the final analysis. The majority of studies used quantitative methods, with only two articles reporting qualitative or mixed methodology. Articles were predominantly cross-sectional studies (n = 10), along with cohort studies (n = 3), clinical trials (n = 3) and pilot studies (n = 2). Results indicated that patients reported a variety of issues influencing their HRQOL, with emotional/psychological/cognitive changes being the most commonly reported. Physical complaints included problems with fatigue, seizures and maintaining daily activity. Social challenges included strained social relationships and issues managing finances. Patient coping strategies were found to significantly influence wellbeing and subsequent HRQOL. CONCLUSION PrBT patients’ long-term HRQOL and daily functioning can be impacted by their physical, mental and social wellbeing. Findings from this review lay the groundwork for efforts to improve patient HRQOL in long-term survivorship.

Many traits of cancer progression (e.g., development of metastases or resistance to therapy) are facilitated by tumour evolution: Darwinian selection of subclones with distinct genotypes or phenotypes that enable such progression. Characterising these subclones provide an opportunity to develop drugs to better target their specific properties but requires the accurate identification of somatic mutations shared across multiple spatiotemporal tumours from the same patient. Current best practices for calling somatic mutations are optimised for single samples, and risk being too conservative to identify shared mutations with low prevalence in some samples. We reasoned that datasets from multiple matched tumours can be used for mutual validation and thus propose an adapted two-stage approach: (1) low-stringency mutation calling to identify mutations shared across samples irrespective of the weight of evidence in a single sample; (2) high-stringency mutation calling to further characterise mutations present in a single sample. We applied our approach to three-independent cohorts of paired primary and recurrent glioblastoma tumours, two of which have previously been analysed using existing approaches, and found that it significantly increased the amount of biologically relevant shared somatic mutations identified. We also found that duplicate removal was detrimental when identifying shared somatic mutations. Our approach is also applicable when multiple datasets e.g. DNA and RNA are available for the same tumour.

Background CNS tumors, including medulloblastoma and pediatric glioblastoma (pGBM) account for the majority of solid pediatric malignancies. There remains an unmet need to identify novel treatment approaches in poor prognosis and relapsed pediatric brain tumors, where therapeutic options are limited. Small-molecule B-cell lymphoma 2 (BCL-2) family inhibitors may enhance tumor cell killing when combined with conventional and targeted chemotherapeutic agents. We investigated the effect of disrupting BCL-2 and B cell lymphoma-extra large (BCL-XL) protein function using ABT-263, ABT-199 and WEHI-539 in medulloblastoma and pGBM cells following treatment with MLN8237, an Aurora kinase inhibitor under investigation as a novel agent for the treatment of malignant brain tumors. Methods Tumor cell growth and viability were determined by MTT/WST-1 assays and flow cytometry. Effects on cell phenotype, cell cycle progression, and ploidy were determined by live cell imaging and DNA content analysis. Apoptosis was determined by annexin V/propidium iodide staining and time-lapse microscopy and confirmed by measuring caspase-3/7 activity and western blotting and by short interfering RNA (siRNA) knockdown of BCL-2 associated X protein/BCL-2 antagonist killer (BAX/BAK). Results ABT-263, in combination with MLN8237, reduced mitotic slippage and polyploidy and promoted the elimination of mitotically defective cells via a BAX/BAK-dependent, caspase-mediated apoptotic pathway. The BCL-XL antagonist, WEHI-539, significantly augmented tumor cell killing when used in combination with MLN8237, as well as sensitized resistant brain tumor cells to a novel BAX activator, SMBA1. In addition, siRNA-mediated knockdown of BCL-XL sensitized pGBM and medulloblastoma cells to MLN8237 and mimicked the effect of combination drug treatment. Conclusion Selective small-molecule inhibitors of BCL-XL may enhance the efficacy of MLN8237 and other targeted chemotherapeutic agents.

BACKGROUND Oncolytic viruses represent a novel treatment approach in GBM through oncolytic targeting as well as local immune activation. We designed a phase Ib, open-label study of intravenous reovirus (pelareorep) with GM-CSF alongside standard chemoradiotherapy to assess safety and tolerability. METHODS 15 patients with newly diagnosed GBM were treated with GM-CSF 50mg subcutaneously (days 1–3) and pelareorep (days 4–5) in weeks 1 and 4 of chemoradiotherapy, and week 1 of adjuvant temozolomide course: 7 patients received 1x1010TCID50 (dose level 1); 8 received 3x1010TCID50 (dose level 2). The primary objective was to determine the maximum tolerated dose of pelareorep and GM-CSF with standard chemoradiotherapy. Secondary objectives were to gain preliminary assessment of the activity of the combination and assess treatment compliance. RESULTS 1 dose limiting toxicity (DLT) and 20 SAEs were experienced overall; median number of SAEs per patient was 2. Commonest SAEs were nervous system disorders, predominantly seizures. SARs included fever/flu-like episodes (n=5), fall (n=1) and headache (n=1). Two SUSARs occurred in dose level 2, classed as vascular disorders manifesting as hypotension episodes – one was a DLT. Suspected relationship of SARs: pelareorep (n=6); temozolomide (n=1); radiotherapy (n=1); all study drugs (n=1). 87% of patients (n=13) completed chemoradiotherapy without unplanned delays. Adjuvant treatment was delayed in 21% of cycles overall, with the majority due to inadequate haematology/biochemistry values (44% of delays). Pelareorep was omitted in 4 instances in 4 patients during chemoradiotherapy and omitted in 4 instances in 3 patients during adjuvant treatment. CONCLUSION We present the first clinical data using intravenous pelareorep with GM-CSF alongside standard chemoradiotherapy in patients with GBM, suggesting that the combination is tolerable. Further analysis is underway and efficacy results will be ready for presentation at the conference. This work was supported by CRUK, The Brain Tumour Charity, Yorkshire Cancer Research and Oncolytics Biotech Inc.

MGMT promoter methylation is the only accepted biomarker with prognostic role in GBM but its routine implementation is limited partly response to TMZ is heterogeneous, but also due to lack of effective alternative treatment options. Therefore, additional biomarkers are needed to enable better prediction of survival and to improve individualized treatment of GBM patients. A potential new biomarker is the epidermal growth factor receptor variant III (EGFRvIII). This constitutively activated deletion variant is present in approximately one third of all IDH wildtype GBM, but its relevance to treatment response is poorly understood. The aim of the present study was to analyze the impact of endogenous EGFRvIII expression on chemosensitivity and the mechanisms underlying any differential treatment response. EGFRvIII expression was associated with prolonged median overall survival but only for GBM patients with MGMT promoter methylated tumors. In line with this, we observed increased TMZ sensitivity of EGFRvIII+ and MGMT promoter methylated cells, which translated into improved survival in xenograft experiments. The increased TMZ sensitivity was associated with an elevated DNA damage induction accompanied by an increased expression of DNA mismatch repair (MMR) proteins in EGFRvIII+ cell lines and EGFRvIII+ GBM patient samples. Subsequently, only a moderate reduction in MMR protein expression resulted in a dramatic TMZ resistance, suggesting that EGFRvIII expression specifically sensitized MGMT deficient cells to TMZ treatment by upregulating MMR. Furthermore, EGFRvIII expression in GBM cell lines was accompanied by increased DNA damage, replication fork slowing, stalling and enhanced origin firing, implying replication stress. Targeting of EGFRvIII-dependent replication stress by irinotecan led to hypersensitivity of EGFRvIII+ cells. Taken together this study illustrates that EGFRvIII-induced upregulation of MMR and replication stress increases chemosensitivity thereby highlighting the vulnerability of EGFRvIII+ GBM to available treatments. These important data may also guide the development of new and more effective personalized strategies.

BACKGROUND Glioblastoma has a poor prognosis despite treatment with surgery and chemo-radiotherapy (CRT). Monitoring early response to CRT is challenging and conventional imaging is sub-optimal for stratifying poorly responding patients for novel agents. Also, imaging is not routinely performed during CRT and consequently, personalised treatment through individualised radiation dose adaption is not possible. AIMS: To evalutate the feasibility of Fluorine-18 Fluciclovine PET-CT for early response assessment during and post-treatment in patients with glioblastoma undergoing standard-of-care CRT. METHODS Patients with confirmed glioblastoma and macroscopic residual tumour post-surgery were consented for PET-CT and MRI prior to CRT (scan 1), after completing 2 weeks (10 fractions) of CRT (scan 2) and 6 weeks after completing treatment (scan 3). For each scan, patients were immobilised in a radiotherapy treatment mask. PET-CT and MRI scans were performed at each timepoint within a few days of each other. Patients were treated and followed up according to local guidelines. RESULTS 6 patients were recruited to the study between June 2018 and May 2019. All patients tolerated the additional imaging without problems. 2 patients were unable to attend their post-treatment PET-CT scan due to clinical deterioration. Fluciclovine PET-CT highlighted potentially active disease beyond the surgical cavity pre-radiotherapy (scan 1) in 3 patients. In 4/6, PET signal persisted after 2 weeks of radiotherapy with stable MRI appearances (scan 2). Frank disease progression was seen in 1 patient on both MRI and PET-CT mid-treatment. 3/4 patients with persistent activity at scan 2, showed disease progression post-treatment on both PET-CT and MRI (scan 3). Another had progressive changes on MRI but stable PET-CT appearances possibly representing pseudoprogression. CONCLUSION These preliminary results suggest that Fluciclovine PET-CT could help in monitoring treatment and further work to assess the ability to guide individualised treatment planning in glioblastoma is warranted.

In 2016 there were 5250 brain cancer deaths in the UK. Standard treatment is surgical resection followed by chemo-radiotherapy. In most cases of diffuse glioma, complete tumour resection is not feasible. Many chemotherapy drugs have untested penetration through the blood brain barrier, potentially leading to sub-therapeutic concentrations in the tumour. There is need to refine current treatment strategies in relation to the understanding of tumour biology, and rapidly introduce and evaluate novel therapeutic approaches and agents through delivering rigorous clinical trials. The TESSA JOWELL BRAIN MATRIX Study will evaluate the feasibility of delivering precision medicine for brain cancer patients within the NHS. A multicentre, platform feasibility study of 1200 patients with diffuse glioma will build on the 100,000 genome project to develop and evaluate an infrastructure to collect and integrate: 1) real time comprehensive integrated molecular analysis, including whole genome sequencing and epigenetic classification; 2) serial sampling and annotation of tumours; 3) collection of matched clinical data; 4) assessment of patient quality of life; 5) centralised radiological review and response assessment as per RANO criteria. Once developed this will allow rapid introduction of therapeutic trials to specific patient groups. Secondary objectives include: understanding the association between extent of resection and molecular stratification to refine the role of surgery; optimisation and harmonisation of protocols to best collect, manage and store tissue, clinical data, and radiological images in order to provide a resource for researchers, both within and outside of the study. Improve patient recruitment by identifying and removing recruitment barriers and improve the information and consent processes for patients. Promote the development of a national network with expertise in brain cancer. Enrolment of the first patient is expected in late 2019. For further information, please contact the Brain Matrix Trial Office BrainMatrix@trials.bham.ac.uk.

Recent findings from our group, and the wider community, show that standard treatment does not impose an apparent bottleneck on the clonal evolution of adult glioblastoma (GBM), implying a lack of direct therapeutic opportunity. This does not negate the possibility that multiple treatment-resistance mechanisms co-exist in tumours, repeated across patients, making a combination of targeted therapies a potentially effective approach. We investigated whether treatment resistance may be driven by selection of cellular properties conferred above the level of the genome. Differential expression analysis was performed on 23 pairs of primary and recurrent tumours from patients who received standard treatment and had a local recurrence treated by surgery and second line chemotherapy. This revealed a treatment-induced shift in cell states linked to normal neurodevelopment. The latter is orchestrated by cascades of transcription factors. We, therefore, applied a bespoke gene set enrichment analysis to our paired expression data to investigate whether any factors were implicated in co-regulation of the genes that were altered through therapy. This identified a specific chromatin remodelling machinery, instrumental in normal neurogenesis. We validated our results in an independent cohort of 22 paired GBM samples. Our results suggest that the chromatin remodelling machinery is responsible for determining transcriptional hierarchies in GBM, shown elsewhere to have different treatment sensitivities such that their relative abundances are altered through treatment.

BackgroundMicroRNAs play an important role in the regulation of mRNA translation, and have therapeutic potential in cancer and other diseases.MethodsTo profile the landscape of microRNAs with significant cytotoxicity in the context of glioblastoma (GBM), we performed a high-throughput screen using a synthetic oligonucleotide library representing all known human microRNAs in adult and pediatric GBM cells. Bio-informatics analysis were used to refine this list and the top seven microRNAs were validated in a larger panel of cells by flow-cytometry, and RTqPCR. The downstream mechanism of the strongest and most consistent candidate was investigated by siRNAs, 3’UTR luciferase assays and Western Blotting.ResultsOur screen identified ∼100 significantly cytotoxic microRNAs with 70% concordance between cell lines. MicroRNA-1300 (miR-1300) was the most potent and robust candidate. We observed a striking binucleated phenotype in miR-1300 expressing cells and characterized the mechanism of action as cytokinesis failure followed by apoptosis, which was observed in an extended GBM cell panel including two stem-like patient-derived cultures. We identified the physiological role of miR-1300 as a regulator of endomitosis in megakaryocyte differentiation where blockade of cytokinesis is an essential step. In glioblastoma cells, the oncogene Epithelial Cell Transforming 2 (ECT2) was validated as a direct key target of miR-1300. ECT2 siRNA phenocopied the effects of miR-1300, and its overexpression led to a significant rescue of miR-1300 induced binucleation.ConclusionMiR-1300 was identified as a novel regulator of endomitosis with translatable potential for therapeutic application. The datatasets will be a resource for the neuro-oncology community.Key points (2 or 3 key points 85 characters plus spaces each)70% of cytotoxic microRNAs were shared between adult and pediatric glioblastoma cellsMiR-1300 expression is restricted to endomitosis within megakaryocyte differentiationMiR-1300’s ectopic expression is a potent and promising therapeutic tool in cancerImportance of StudyPrevious functional studies of microRNAs involved in the regulation of glioblastoma cell proliferation and/or survival have focused on adult glioblastoma alone and are restricted to only a few microRNAs at a time. Our study provides the first encompassing landscape of potent cytotoxic microRNAs in pediatric and adult glioblastoma.Not only, does our data provide an invaluable resource for the research community but it also revealed that 70% of microRNAs with significant cytotoxicity were shared by adult and pediatric cells. Finally, we identified and characterized the previously undescribed role of microRNA-1300 in the tight regulation of megakaryocyte differentiation into platelets and how, when expressed outside of this context, miR-1300 consistently causes cytokinesis failure followed by apoptosis, and thus represents a powerful cytotoxic tool with potential for translation towards therapeutic applications.

BACKGROUND Glioblastoma (GBM) tumours recur following standard treatment in almost all cases. We use ‘omics technologies to simultaneously profile pairs of primary and matched recurrent GBM to specifically identify and characterise the cells that resisted treatment, with the aim of determining how to more effectively kill them. MATERIAL AND METHODS We have analysed high coverage RNAseq data from pairs of GBM tumours: primary de novo tumour and matched local recurrence from patients that underwent standard therapy. Our original cohort constituted 23 pairs and our validation cohort was an additional 22 pairs. We also cultured two plates of spheroids directly from a patient’s GBM, treating one with radiation and temozolomide. We monitored growth and captured and sequenced RNA from single cells at two time-points: one week post-treatment when the deviation between untreated and treated spheroid growth curves was most pronounced; and three weeks post-treatment when the growth rate of treated spheroids had recovered. We investigated differential gene expression between primary and recurrent pairs, and single cells pre- and post-treatment, and performed a bespoke per patient gene set enrichment analysis. RESULTS Differential gene expression analysis in 23 tumour pairs indicated a treatment-induced shift in cell states linked to normal neurogenesis and prompted us to develop a novel gene set enrichment analysis approach to identify gene regulatory factors that may orchestrate such a shift. This revealed the significant and universal dysregulation of genes, through therapy, that are targeted by a specific chromatin remodeling machinery. This finding was validated in an independent cohort of 22 further GBM pairs. To understand the therapeutic potential of this finding we must determine whether genes are dysregulated through therapy owing to a) their fixed expression in inherently treatment resistance cells in the primary tumour which get selected during therapy to increase the signal of that profile, or b) changes in expression during the process of cells acquiring treatment resistance. To inspect this, we analysed single cell gene expression data from GBM spheroids pre- and post-treatment. We found that there was significant dysregulation of the genes associated with the chromatin remodeling complex but only at the three-week post-treatment time-point. CONCLUSION Our results indicate that GBM cells are being transcriptionally reprogrammed in response to treatment; the mechanism of which may represent a therapeutic opportunity.

BackgroundGlioblastoma (GBM) is a fatal and incurable brain cancer with a dismal prognosis. In order to impact on this disease, we need to understand how infiltrating, non resectable tumour cells resist chemoradiation and facilitate disease recurrence. To this end, we generated or acquired bulk tumour RNA sequencing data from 45 paired primary and locally recurrent GBM tumours (split into original and validation cohorts) from patients that received standard treatment. We also generated DNA methylation profiles for 9 pairs and sequenced RNA from single cells isolated from a patient derived GBM spheroid model at different timepoints following in vitro chemoradiation.ResultsWe have identified a set of genes with Jumonji and AT-Rich Interacting Domain 2 (JARID2) binding sites in their promoters that are universally dysregulated in post-standard treatment recurrent GBMs compared to the primary tumour. The direction of dysregulation is patient-dependent and not associated with differential promoter DNA methylation. Our in vitro experiments suggest that this dysregulation occurs dynamically following treatment as opposed to resulting from selection of cells with specific expression profiles.ConclusionJARID2 is an accessory protein to a chromatin remodeling complex, responsible for histone modifications observed during cell state transitions in both normal brain and GBM. We propose that JARID2 facilitates GBM recurrence following treatment by indirect transcriptional reprogramming of surviving cells in whichever manner is needed to reproduce the phenotypic heterogeneity required for tumour regrowth in vivo. The mechanism of this reprogramming may present a therapeutic vulnerability for more effective treatment of GBM.

The heterogeneous and invasive nature of pediatric gliomas poses significant treatment challenges, highlighting the importance of identifying novel chemotherapeutic targets. Recently, recurrent Fibroblast growth factor receptor 1 (FGFR1) mutations in pediatric gliomas have been reported. Here, we explored the clinical relevance of FGFR1 expression, cell migration in low and high grade pediatric gliomas and the role of FGFR1 in cell migration/invasion as a potential chemotherapeutic target. A high density tissue microarray (TMA) was used to investigate associations between FGFR1 and activated phosphorylated FGFR1 (pFGFR1) expression and various clinicopathologic parameters. Expression of FGFR1 and pFGFR1 were measured by immunofluorescence and by immunohistochemistry (IHC) in 3D spheroids in five rare patient-derived pediatric low-grade glioma (pLGG) and two established high-grade glioma (pHGG) cell lines. Two-dimensional (2D) and three-dimensional (3D) migration assays were performed for migration and inhibitor studies with three FGFR1 inhibitors. High FGFR1 expression was associated with age, malignancy, tumor location and tumor grade among astrocytomas. Membranous pFGFR1 was associated with malignancy and tumor grade. All glioma cell lines exhibited varying levels of FGFR1 and pFGFR1 expression and migratory phenotypes. There were significant anti-migratory effects on the pHGG cell lines with inhibitor treatment and anti-migratory or pro-migratory responses to FGFR1 inhibition in the pLGGs. Our findings support further research to target FGFR1 signaling in pediatric gliomas.

Patients with glioblastoma (GBM) have a poor prognosis, and inefficient delivery of drugs to tumors represents a major therapeutic hurdle. Hematopoietic stem cell (HSC)-derived myeloid cells efficiently home to GBM and constitute up to 50% of intratumoral cells, making them highly appropriate therapeutic delivery vehicles. Because myeloid cells are ubiquitously present in the body, we recently established a lentiviral vector containing matrix metalloproteinase 14 (MMP14) promoter, which is active specifically in tumor-infiltrating myeloid cells as opposed to myeloid cells in other tissues, and resulted in a specific delivery of transgenes to brain metastases in HSC gene therapy. Here, we used this novel approach to target transforming growth factor beta (TGFβ) as a key tumor-promoting factor in GBM. Transplantation of HSCs transduced with lentiviral vector expressing green fluorescent protein (GFP) into lethally irradiated recipient mice was followed by intracranial implantation of GBM cells. Tumor-infiltrating HSC progeny was characterized by flow cytometry. In therapy studies, mice were transplanted with HSCs transduced with lentiviral vector expressing soluble TGFβ receptor II–Fc fusion protein under MMP14 promoter. This TGFβ-blocking therapy was compared with the targeted tumor irradiation, the combination of the two therapies, and control. Tumor growth and survival were quantified (statistical significance determined by t-test and log-rank test). T cell memory response was probed through a repeated tumor challenge. Myeloid cells were the most abundant HSC-derived population infiltrating GBM. TGFβ-blocking HSC gene therapy in combination with irradiation significantly reduced tumor burden as compared with monotherapies and the control, and significantly prolonged survival as compared with the control and TGFβ-blocking monotherapy. Long-term protection from GBM was achieved only with the combination treatment (25% of the mice) and was accompanied by a significant increase in CD8+ T cells at the tumor implantation site following tumor rechallenge. We demonstrated a preclinical proof-of-principle for tumor myeloid cell-specific HSC gene therapy in GBM. In the clinic, HSC gene therapy is being successfully used in non-cancerous brain disorders and the feasibility of HSC gene therapy in patients with glioma has been demonstrated in the context of bone marrow protection. This indicates an opportunity for clinical translation of our therapeutic approach.

Glioblastoma multiforme (GBM) is the most common malignant brain tumor in adults. The current standard of care includes surgery followed by radiotherapy (RT) and chemotherapy with temozolomide (TMZ). Treatment often fails due to the radiation resistance and intrinsic or acquired TMZ resistance of a small percentage of cells with stem cell-like behavior (CSC). The NOTCH signaling pathway is expressed and active in human glioblastoma and NOTCH inhibitors attenuate tumor growth in vivo in xenograft models. Here we show using an image guided micro-CT and precision radiotherapy platform that a combination of the clinically approved NOTCH/γ-secretase inhibitor (GSI) RO4929097 with standard of care (TMZ + RT) reduces tumor growth and prolongs survival compared to dual combinations. We show that GSI in combination with RT and TMZ attenuates proliferation, decreases 3D spheroid growth and results into a marked reduction in clonogenic survival in primary and established glioma cell lines. We found that the glioma stem cell marker CD133, SOX2 and Nestin were reduced following combination treatments and NOTCH inhibitors albeit in a different manner. These findings indicate that NOTCH inhibition combined with standard of care treatment has an anti-glioma stem cell effect which provides an improved survival benefit for GBM and encourages further translational and clinical studies.

INTRODUCTION: Gliomas are intrinsic brain tumours characterised by their highly invasive, malignant and aggressive nature. Persistently poor prognoses highlight the urgent clinical need to identify novel approaches and therapeutic targets to improve glioma management. Recently we reported a correlation of fibroblast growth factor receptor 1 (FGFR1) expression with malignancy, tumour grade and location in paediatric gliomas. There is evidence that the L1 cell adhesion molecule (L1CAM) potentiates FGFR1 signalling. L1CAM is a transmembrane glycoprotein associated with poor clinical outcomes in various cancers promoting cell motility. Here, following our initial studies on FGFR1, we investigated FGFR1 in its activated phosphorylated form (pFGFR1) as well as L1CAM expression in our cohort and association with various clinicopathological parameters. METHODS. A commercially available tissue microarray (CNS2081, US Biomax) was stained for pFGFR1 and L1CAM expression and data was scored using manual and digital assessment (QuPath). Scores were separately dichotomised into low and high L1CAM and pFGFR1 expression using the median value in SPSS. A two-sided Pearson’s chi squared statistical test was performed using GraphPad Prism where p

BACKGROUND: Treating elderly patients with glioblastoma remains challenging and alternatives to conventional cytotoxics, particularly in patients with unmethylated tumours are required. Pre-clinical data suggest that autophagy inhibition sensitizes gliomas to radiotherapy and chemotherapy MATERIAL AND METHODS: We conducted an open-label multicentre randomized phase-II study of patients aged >=70, performance status 0–1 with newly diagnosed high-grade glioma considered suitable for short course radiotherapy. They were randomized (1:2) to a calibration arm given radiotherapy (RT) alone (30Gy;5Gy/6fractions over 2 weeks), or an experimental arm given RT plus hydroxychloroquine (HCQ, 200mg orally twice daily) from 7 days prior to RT until progression/toxicity. The primary endpoint was one-year overall survival (OS; target 34%). Secondary endpoints included progression free survival (PFS), quality of life and toxicity. RESULTS: Fifty-three patients with median age 75 were included May 2013 to Oct 2016 (n=35 RT+HCQ, n=18 RT alone). One-year survival was 20.3% (95%CI 8–36) in the experimental arm and median OS was 7.9 months. In the calibration arm, one-year survival was 47.6% (95%CI 2–71) and median OS was 11.8 months. Six-month PFS was 25.2% vs 36.5%. Grade 3–5 toxicities occurred in 60% (RT+HCQ) and 38.8% (RT alone), which was not significantly different, with no obvious imbalance in specific events. Common toxicities included lethargy and pulmonary infections. QoL did not differ between arms. The Data Monitoring Committee stopped recruitment early because the experimental arm could not reach its target 1-year OS CONCLUSION: Despite growing interest in autophagy inhibition as a potential mechanism for treating cancer, giving HCQ with short course radiotherapy did not improve outcomes compared to radiotherapy alone. Although median OS was similar to data from other studies for this patient group, it was worse than the calibration arm. Future opportunities could include using higher doses of HCQ, or definition of selective biomarkers for response to autophagy inhibition.

Pharmacological inhibition of uncontrolled cell growth with small-molecule inhibitors is a potential strategy for treating glioblastoma multiforme (GBM), the most malignant primary brain cancer. We showed that the synthetic small-molecule KHS101 promoted tumor cell death in diverse GBM cell models, independent of their tumor subtype, and without affecting the viability of noncancerous brain cell lines. KHS101 exerted cytotoxic effects by disrupting the mitochondrial chaperone heat shock protein family D member 1 (HSPD1). In GBM cells, KHS101 promoted aggregation of proteins regulating mitochondrial integrity and energy metabolism. Mitochondrial bioenergetic capacity and glycolytic activity were selectively impaired in KHS101-treated GBM cells. In two intracranial patient-derived xenograft tumor models in mice, systemic administration of KHS101 reduced tumor growth and increased survival without discernible side effects. These findings suggest that targeting of HSPD1-dependent metabolic pathways might be an effective strategy for treating GBM.

Introduction UK Neuro-Oncologists and multidisciplinary colleagues are developing one of the first randomised clinical trials of proton beam radiotherapy(PBT) to compare quality of life(QOL), cognitive function and other late effects in adults with good prognosis glioma following either PBT or photon radiotherapy. The feasibility of running randomised studies with PBT is an important consideration, particularly in respect of participants’ views of a randomised design requiring treatment at national centres. We sought patient and carer engagement on our proposals to ensure we incorporate their views. Methods To explore these issues, we invited patients who had previously completed radiotherapy for oligodendroglioma and their carers to attend a focus group in Manchester in November 2018. Fifteen participants attended. We sought views on our trial proposal through small group discussions centred around 5 questions, led and facilitated by neuro-oncologists, a research radiographer, neuro-psychologist and statistician. Results Participants strongly endorsed the trial proposal and positively highlighted the opportunity to access PBT within a clinical trial and the group recognised and supported the need for randomisation and stated this should be 1:1. Patients disliked some traditional terminology such as ‘trial’ and ‘neurocognitive tests’ and preferred ‘research study’ and ‘neurocognitive assessments’. Patient and carers expressed the need for careful consideration of issues around travel and accommodation during PBT away from home. Interestingly, participants considered that standard QOL questionnaires fail to address some important areas reflecting daily wellbeing. Conclusion We acknowledge and will now incorporate these important patient and carer observations to strengthen our study and add validity to the key study endpoints.

Background Systemic delivery of a complementary cDNA library expressed from the vesicular stomatitis virus (VSV) treats tumors by vaccinating against a wide range of tumor associated antigens (TAAs). For subcutaneous B16 melanomas, therapy was achieved using a specific combination of self-TAAs (neuroblastoma-Ras, cytochrome c, and tyrosinase-related protein 1) expressed from VSV. However, for intracranial B16 tumors, a different combination was therapeutic (consisting of VSV-expressed hypoxia-inducible factor [HIF]–2α, Sox-10, c-Myc, and tyrosinase-related protein 1). Therefore, we tested the hypothesis that tumors of different histological types growing in the brain share a common immunogenic signature which can be exploited for immunotherapy. Methods Syngeneic tumors, including GL261 gliomas, in the brains of immune competent mice were analyzed for their antigenic profiles or were treated with systemic viroimmunotherapy. Results Several different histological types of tumors growing intracranially, as well as freshly resected human brain tumor explants, expressed a HIF-2αHi phenotype imposed by brain-derived CD11b+ cells. This location-specific antigen expression was exploited therapeutically against intracranial GL261 gliomas using systemically delivered VSV expressing HIF-2α, Sox-10, and c-Myc. Viroimmunotherapy was enhanced by immune checkpoint inhibitors, associated with the de-repression of antitumor T-helper cell type 1 (Th1) interferon-γ and Th17 T cell responses. Conclusions Since different tumor types growing in the same location in the brain share a location-specific phenotype, we suggest that antigen-specific immunotherapies should be based upon expression of both histological type–specific tumor antigens and location-specific antigens. Our findings support clinical application of VSV-TAA therapy with checkpoint inhibition for aggressive brain tumors and highlight the importance of the intracranial microenvironment in sculpting a location-specific profile of tumor antigen expression.

Immune checkpoint inhibitors, including those targeting programmed cell death protein 1 (PD-1), are reshaping cancer therapeutic strategies. Evidence suggests, however, that tumor response and patient survival are determined by tumor programmed death-ligand 1 (PD-L1) expression. We hypothesized that preconditioning of the tumor immune microenvironment using targeted, virus-mediated interferon (IFN) stimulation, would upregulate tumor PD-L1 protein expression and increase cytotoxic T cell infiltration, improving the efficacy of subsequent checkpoint blockade. Oncolytic viruses (OVs) represent a promising form of cancer immunotherapy. For brain tumors, almost all studies to date have used direct intralesional injection of OV, because of the largely untested belief that intravenous (i.v.) administration will not deliver virus to this site. Here we show, in a window-of-opportunity clinical study, that i.v. infusion of oncolytic human Orthoreovirus (referred to herein as reovirus), leads to infection of tumor cells subsequently resected as part of standard clinical care, both in high-grade glioma (HGG) and in brain metastases, and increases cytotoxic T cell tumor infiltration relative to patients not treated with virus. We further show that reovirus upregulates IFN-regulated gene expression, as well as the PD-1/PD-L1 axis in tumors, via an IFN-mediated mechanism. Finally, we show that addition of PD-1 blockade to reovirus enhances systemic therapy in a preclinical glioma model. These results support the development of combined systemic immunovirotherapy strategies for the treatment of both primary and secondary tumors in the brain.

Background: Paediatric high grade glioma (pHGG) and diffuse intrinsic pontine glioma (DIPG) are highly aggressive brain tumours. Their invasive phenotype contributes to their limited therapeutic response, and novel treatments that block brain tumour invasion are needed. Methods: Here, we examine the migratory characteristics and treatment effect of small molecule glycogen synthase kinase-3 inhibitors, lithium chloride (LiCl) and the indirubin derivative 6-bromoindirubin-oxime (BIO), previously shown to inhibit the migration of adult glioma cells, on two pHGG cell lines (SF188 and KNS42) and one patient-derived DIPG line (HSJD-DIPG-007) using 2D (transwell membrane, immunofluorescence, live cell imaging) and 3D (migration on nanofibre plates and spheroid invasion in collagen) assays. Results: All lines were migratory, but there were differences in morphology and migration rates. Both LiCl and BIO reduced migration and instigated cytoskeletal rearrangement of stress fibres and focal adhesions when viewed by immunofluorescence. In the presence of drugs, loss of polarity and differences in cellular movement were observed by live cell imaging. Conclusions: Ours is the first study to demonstrate that it is possible to pharmacologically target migration of paediatric glioma in vitro using LiCl and BIO, and we conclude that these agents and their derivatives warrant further preclinical investigation as potential anti-migratory therapeutics for these devastating tumours.

Despite many clinical efforts, the prognosis of GBM patients has not improved in the last 10 years. Epigenetic silencing of the O6-methylguanine-DNA-methyltransferase (MGMT) gene is the only predictive biomarker that is associated with temozolomide (TMZ) response. The establishment of new biomarkers, for personalized treatment is of significant interest. The epidermal growth factor receptor (EGFR) variant III (EGFRvIII) is expressed in approximately 20–30% of GBM. The aim of this study was to investigate if EGFRvIII is a predictive biomarker for TMZ response by analyzing the TMZ sensitivity of isogenic cell cultures and tumour xenografts with/without endogenous EGFRvIII expression. Using two, unique isogenic pairs of MGMT deficient GBM cells we observed that endogenous EGFRvIII expression was associated with a significant increase in TMZ sensitivity in vitro and in vivo. Knockdown of EGFRvIII restored TMZ resistance, confirming EGFRvIII dependence. We observed prolonged accumulation in S/G2-phase in EGFRvIII+ cells after TMZ treatment, indicating increased replication stress induced by TMZ and a significantly higher number of DNA double strand breaks. Because TMZ sensitivity in MGMT negative cells is predominantly determined by functional mismatch repair (MMR), we next analyzed MMR protein expression. We observed that EGFRvIII expression was associated with upregulated MMR proteins and that conversely, even a moderate decrease in MSH6 and MLH1 expression yielded a pronounced increase in TMZ resistance. In accordance with our findings, analysis of clinical data revealed that EGFRvIII positive GBM patients displaying MGMT promotor methylation have significantly better outcomes than EGFRvIII negative patients. In summary, we have shown that MGMT negative EGFRvIII expressing GBM cells and tumours are significantly more sensitive to TMZ compared to isogenic EGFRvIII negative counterparts due to upregulated MMR. Our data highlight a new mechanism of TMZ sensitivity and we conclude that EGFRvIII is a predictive biomarker for response to TMZ in MGMT methylated GBM patients.

Pharmacological inhibition of uncontrolled cell growth with small molecule inhibitors is a potential strategy against glioblastoma multiforme (GBM), the most malignant primary brain cancer. Phenotypic profiling of the neurogenic small molecule KHS101 revealed the chemical induction of lethal cellular degradation in molecularly-diverse GBM cells, independent of their tumor subtype, whereas non-cancerous brain cells remained viable. Mechanism-of-action (MOA) studies showed that KHS101 specifically bound and inhibited the mitochondrial chaperone HSPD1. In GBM but not non-cancerous brain cells, KHS101 elicited the aggregation of an enzymatic network that regulates energy metabolism. Compromised glycolysis and oxidative phosphorylation (OXPHOS) resulted in the metabolic energy depletion in KHS101-treated GBM cells. Consistently, KHS101 induced key mitochondrial unfolded protein response factor DDIT3 in vitro and in vivo, and significantly reduced intracranial GBM xenograft tumor growth upon systemic administration, without discernible side effects. These findings suggest targeting of HSPD1-dependent oncometabolic pathways as an anti-GBM therapy.

Purpose: The DNA mismatch repair (MMR) pathway is required for the maintenance of genome stability. Unsurprisingly, mutations in MMR genes occur in a wide range of different cancers. Studies thus far have largely focused on specific tumor types or MMR mutations; however, it is becoming increasingly clear that a therapy targeting MMR deficiency in general would be clinically very beneficial. Experimental Design: Based on a drug-repositioning approach, we screened a large panel of cell lines with various MMR deficiencies from a range of different tumor types with a compound drug library of previously approved drugs. We have identified the potassium-sparing diuretic drug triamterene, as a novel sensitizing agent in MMR-deficient tumor cells, in vitro and in vivo. Results: The selective tumor cell cytotoxicity of triamterene occurs through its antifolate activity and depends on the activity of the folate synthesis enzyme thymidylate synthase. Triamterene leads to a thymidylate synthase-dependent differential increase in reactive oxygen species in MMR-deficient cells, ultimately resulting in an increase in DNA double-strand breaks. Conclusions: Conclusively, our data reveal a new drug repurposing and novel therapeutic strategy that has potential for the treatment of MMR deficiency in a range of different tumor types and could significantly improve patient survival. Clin Cancer Res; 23(11); 2880–90. ©2016 AACR.

BACKGROUND: Dysregulated, stem cell-like self-renewal has been implicated in glioma treatment resistance and tumour recurrence. Drugs that eliminate tumour cells possessing this malignant characteristic are urgently needed. It remains, however, an experimental challenge to link heterogeneous glioma genotypes to drug response at scale. To this end, we successfully derived patient-specific induced pluripotent stem cell (iPSC) models from both low- (LGG) and high-grade gliomas (HGG) and developed an initial drug discovery application. METHODS: Brain tumour tissue, acquired at surgery, was reprogrammed. Derived iPSC models were characterised using pluripotency markers, tri-germinal layer differentiation, gene expression, karyology and deep whole genome sequencing (WGS, iPSC versus parental tumour). Glioma iPSC differentiation in 2-dimensional (adherent, optically clear 96-well imaging plates) and 3-dimensional (organoid) culture was carried out. Gene expression of neural induction and neuronal differentiation was analysed using mRNA-seq. Neural cancer stem cells from each glioma iPSC line were orthotopically implanted in vivo. RESULTS: Reprogrammed cells were confirmed as fully-reprogramed/stable iPSCs, with mutational variants (SNPs, CNVs) preserved as compared to the parental tumours. Glioma iPSC maturation and quantification of TUJ-1 expression indicated a ‘differentiation block’ in the HGG iPSC models. This phenotype was concordant in HGG iPSC-derived tumour organoids which displayed SOX2/MKI67-positive neural rosettes. Consistently, mice developed xenograft tumours with GBM histopathological characteristics. Expression profiling during neuronal differentiation (from iPSC to neural stem cells to neurons) has revealed candidate genes that may be responsible for the phenotypic differences between HGG and control/LGG iPSC models. CONCLUSIONS: Our adherent, organoid and in vivo iPSC models may uncover genetic mutations and regulatory networks underlying glioma stem cell self-renewal capability, and provide a basis for industrial-scale drug discovery. Here we have successfully implemented the first stages towards this development (in a 96-well assay format). Ultimately, our patient-derived iPSC-based approach may enable personalised precision medicine strategies against glioma.

One of the biggest challenges when treating brain tumours is achieving efficient delivery of therapeutic agents to the brain and more specifically to the cancer cells. MicroRNA-1300 was identified in our group as a very promising therapeutic microRNA given its cytotoxic effect when introduced in both established as well as cancer-stem-like patient-derived glioblastoma cultures, while not affecting differentiated glioblastoma cells. We are now collaborating to assess the potential efficiency of the natural biopolymer chitosan to form nanocomplexes containing the mature form of microRNA-1300 for delivery. Chitosan has been established as a highly attractive biocompatible polymer to deliver both in vitro and in vivo therapeutic nucleotides intracellularly. In previous studies, we have shown chitosan’s efficacy to form spherical nanocomplexes with microRNA and apply them to the downregulation of JAMA-A mRNA in MCF-7 breast cancer cells. Chitosan can also be chemically conjugated to introduce affinity towards a wide range of cellular targets (e.g. with aptamers). Methods We have optimised of the composition and characterised the biophysical properties of chitosan-microRNA nanocomplexes of varying (+/-) charge ratios using both a control nontargeting microRNA coupled to a fluorochrome (CS-miRdy547, efficiency of cell entry) and mature microRNA-1300 (CS-mi1300, efficient release and biological effect). We have tested the nanocomplexes in 2D monolayers and 3D spheroid cultures on established U251 as well as two patient-derived cultures. Reverse transfection was used as positive control. Results The control nanoparticles of CS-miRdy547 are taken up by the patient-derived cultures in 2D and 3D. Analysis is ongoing using the CS-miR-1300 nanoparticles.

Background A neuro-oncology research radiographer was included in the multi-disciplinary study team (MDT) from the set-up stage of a new advanced imaging study in glioblastoma, as it was envisaged that this would enhance progress and provide better patient-centred care. Aims This pilot study aimed to include 12 participants. This specialist radiographer role was to support recruitment, co-ordinate appointments and monitor patients’ progress. We aimed to ensure that optimal treatment and patient-centred care remained at the forefront of the study pathway. Method Patients were identified and approached by the radiographer prior to consent by a trial investigator. Additional scans were planned prior to radiotherapy (RT), 2 weeks into RT and 6 weeks post RT. The radiographer ensured streamlined appointments and was present during each study visit to liaise with health professionals, provide a specific point of contact with the patient and to ensure continuity. Results 6 patients have been recruited since November 2018. The specialist radiographer has attended 28 study scans to date. Over 40 face-to-face interactions have been undertaken, 30 email communications and 18 telephone consultations. Patient feedback has been extremely positive, all patients convey that they feel supported and value continuity throughout the pathway. Enhanced communication across the entire study team has also guaranteed efficient recruitment. Conclusion The research radiographer has a key role in the multi-disciplinary team delivering this study. Effective liaison between the radiotherapy and imaging departments has been crucial and patients value a consistent point of contact through the study and treatment pathways.

BACKGROUND Glioblastoma multiforme (GBM) carries a poor prognosis, partly due to biological and anatomical heterogeneity. Although radiotherapy (RT) is effective, high doses damage surrounding healthy tissues. Multimodal imaging with Magnetic Resonance (MRI) and Positron Emission Tomography (PET) may represent a useful approach for identifying GBM heterogeneity and visualising metabolic tumour properties. PET radiotracer [18F]-fluciclovine is preferentially accumulated in gliomas compared to healthy brain tissue via the cellular transport systems, LAT1 and ASCT2. In this study the effect of fractionated RT using multimodal imaging including [18F]-fluciclovine uptake and immunohistochemistry (IHC) in a GBM preclinical model will be validated. MATERIAL AND METHODS Two C57BL/6J mice cohorts were injected intracranially (i.c.) with murine CT2A-luc cells and subsequently submitted to multiparametric MRI and [18F]-fluciclovine PET imaging during hemi-brain RT (3Gy on 2 days/each week) for maximum 25 days after i.c. injection. Brains were collected for IHC characterization including LAT1 and ASCT2 staining. RESULTS Preliminary data showed that both MRI and PET were effective modalities to track tumour growth in this model. PET data revealed up to greater than 3-fold increase in SUVmax from regions of interest around the tumour site compared to healthy brain tissue. Time activity curves showed a steady increase in tumour uptake over 90 minutes. MRI showed a 25% increase in T2 values in tumours relative to unaffected contralateral regions. Confirmation of treatment response through matched imaging and IHC are ongoing, from which changes in glioma cell biology as well as amino acid transporter protein levels will be analysed. CONCLUSION These preliminary results show that multimodal imaging presents novel data in the assessment of treatment response in this model and will permit parallel IHC analyses to better define GBM tumour heterogeneity aligned with imaging changes. These data will also inform an on-going clinical study using the same imaging modalities. Work at authors’ labs are supported by an Investigator initiated project from Blue Earth Diagnostics (AS, SCS) and a University of Leeds Biswas studentship (SCS, DS). Daniela Salvatore is also supported by a Scholarship provided by Molecular and Translational Medicine Doctorate School of University of Milan (Italy).