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Glioblastoma (GBM) is a fatal primary malignant brain tumor in adults. Despite decades of research, the prognosis for GBM patients is still disappointing. One major reason for the intense therapeutic resistance of GBM is inter- and intra-tumor heterogeneity. GBM-intrinsic transcriptional profiling has suggested the presence of at least three subtypes of GBM: the proneural, classic, and mesenchymal subtypes. The mesenchymal subtype is the most aggressive, and patients with the mesenchymal subtype of primary and recurrent tumors tend to have a worse prognosis compared with patients with the other subtypes. Furthermore, GBM can shift from other subtypes to the mesenchymal subtype over the course of disease progression or recurrence. This phenotypic transition is driven by diverse tumor-intrinsic molecular mechanisms or microenvironmental factors. Thus, better understanding of the plastic nature of mesenchymal transition in GBM is pivotal to developing new therapeutic strategies. In this review, we provide a comprehensive overview of the current understanding of the elements involved in the mesenchymal transition of GBM and discuss future perspectives.

Development of de novo dural arteriovenous fistula (DAVF) at a different site after resolution of an initial DAVF, is rare. Here we report two cases, which we encountered in our hospital. A 68-year-old woman presented with pulsatile tinnitus on the left side. Cerebral angiography demonstrated a left anterior condylar confluence (ACC) DVAF and she underwent transvenous embolization. Four years after this treatment, she presented with tinnitus on the left side, and cerebral angiography revealed a right DAVF around the sinus of the lesser sphenoid wing. Another 69-year-old woman presented with left-sided orbital bruits, chemosis, and conjunctival hyperemia. Cerebral angiography showed left cavernous sinus (CS) DAVF, for which she underwent transvenous embolization for CS DAVF. One year later, she developed a left ACC and transverse-sigmoid sinus (TSS) DAVF.

We reviewed the outcomes of glioma patients enrolled in a prospective observational registry study of proton beam therapy (PBT) in Japan. The inclusion criteria were glioma patients registered in the Electronic Data Capture system, the Proton-net, between May 2016 and July 2019. Data on patient characteristics, treatments, late adverse events, survival status, recurrence and secondary tumors were extracted and statistically analyzed. The primary endpoint was the overall survival (OS) rate, and the secondary endpoints were the progression-free survival (PFS) rate and cumulative local recurrence rate (cLRR). Of the 65 primary brain tumor patients registered, 29 glioma patients from eight of 19 PBT facilities met the inclusion criteria. There were 19 glioblastoma patients, eight of other malignant gliomas, and two of low-grade gliomas. For glioblastomas, with a median follow-up period of 16 months, the median survival time was 21.2 months and the OS at 1, 2, 3 and 4 years were 77.4%, 44.9%, 23.9% and 23.9%, respectively. The median PFS period was 10.1 months, the 1, 2, 3 and 4-year PFS were 32.4%, 19.4%, 9.7% and 9.7%, respectively. The 1, 2, 3 and 4-year cLRR were 56.1%, 68.8%, 78.4 and 78.4%, respectively. Grade 3 brain necrosis was observed in two patients. No secondary tumor was observed. This is the first report on the current status of PBT for gliomas in Japan. For glioblastomas, the outcomes of PBT are estimated to be equivalent to historical data of photon therapy. The results of a prospective comparative evaluation of PBT and photon therapy are awaited.

Supplementary Figure 2 shows In vitro scratch migration assay.

Glioma cell cytotoxicity with bevacizumab treatment in vitro

Supplementary Figure 3 shows Full scans of the western blotting shown in the figure 6.

Bevacizumab increased the rate of wound closure

Anti-VEGF treatments such as bevacizumab have demonstrated convincing therapeutic advantage in patients with glioblastoma. However, bevacizumab has also been reported to induce invasiveness of glioma. In this study, we examined the effects of rapid antiangiogenesis mediated by oncolytic virus (RAMBO), an oncolytic herpes simplex virus-1 expressing vasculostatin, on bevacizumab-induced glioma invasion. The effect of the combination of RAMBO and bevacizumab in vitro was assessed by cytotoxicity, migration, and invasion assays. For in vivo experiments, glioma cells were stereotactically inoculated into the brain of mice. RAMBO was intratumorally injected 7 days after tumor inoculation, and bevacizumab was administered intraperitoneally twice a week. RAMBO significantly decreased both the migration and invasion of glioma cells treated with bevacizumab. In mice treated with bevacizumab and RAMBO combination, the survival time was significantly longer and the depth of tumor invasion was significantly smaller than those treated with bevacizumab monotherapy. Interestingly, RAMBO decreased the expression of cysteine-rich protein 61 and phosphorylation of AKT, which were increased by bevacizumab. These results suggest that RAMBO suppresses bevacizumab-induced glioma invasion, which could be a promising approach to glioma therapy.

The combination of bevacizumab with temozolomide and radiotherapy was shown to prolong progression-free survival in newly diagnosed patients with glioblastoma, and this emphasizes the potential of bevacizumab as a glioma treatment. However, although bevacizumab effectively inhibits angiogenesis, it has also been reported to induce invasive proliferation. This study examined gene expression in glioma cells to investigate the mechanisms of bevacizumab-induced invasion. We made a human glioma U87ΔEGFR cell xenograft model by stereotactically injecting these cells into the brain of animals. We administered bevacizumab intraperitoneally three times per week. At 18 days after tumor implantation, the brains were removed for histopathology and mRNA was extracted. In vivo, bevacizumab treatment increased glioma cell invasion. qRT-PCR array analysis revealed upregulation of δ-catenin (CTNND2) and several other factors. In vitro, bevacizumab treatment upregulated δ-catenin expression. A low concentration of bevacizumab was not cytotoxic, but tumor cell motility was increased in scratch wound assays and two-chamber assays. Overexpression of δ-catenin increased the tumor invasion in vitro and in vivo. However, δ-catenin knockdown decreased glioma cell invasiveness. The depth of tumor invasion in the U87ΔEGFR cells expressing δ-catenin was significantly increased compared with empty vector-transfected cells. The increase in invasive capacity induced by bevacizumab therapy was associated with upregulation of δ-catenin expression in invasive tumor cells. This finding suggests that δ-catenin is related to tumor invasion and migration.

WST-1 assay and two-chamber assay

Bevacizumab treatment led to increase in invasive and high expression of Î'-catenin. Silencing of Î'-catenin decreased bevacizumab-induced glioma invasion and Î'-catenin expression. Overexpressed Î'-catenin tumor cells showed more invasiveness and expressed high level ofÎ'-catenin protein in the tumor area in vivo.

Supplementary Figure 1 shows Evaluation of glioma cells infected by oncolytic virus and conditioned medium.

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In neurosurgery, perioperative surgical site infection(SSI)is associated with complicated postoperative management, prolonged hospital stay, and patient stress. In this article, we review SSI in the field of skull base surgery, including endoscopic endonasal surgery, and discuss ways to prevent SSI. In a craniotomy, in which the frontal sinus is revealed, prevention of cerebrospinal fluid(CSF)leakage by reliable repair of the dura and frontal sinus reduces SSI. In addition, prevention of postoperative CSF leakage by reliable skull base reconstruction in endoscopic endonasal surgery contributes to the prevention of SSI. Prophylactic antibiotics are often reported to be useful, and cephalosporin or sulbactam/ampicillin intravenous injections are generally used. There are insufficient data to recommend lumbar drainage for the management of SSI and postoperative CSF leak. Skull base surgery is often a clean-contaminated surgery, and serious complications can be prevented by proper understanding and performance of the appropriate method as required. However, no studies with a high level of evidence on SSI in the field of skull base surgery exist. New large randomized controlled trials are expected to evaluate the efficacy of prophylactic antibiotics in skull base surgery.

Although temporary clipping of the parent artery is an indispensable technique in clipping surgery for intracranial aneurysms, the permissive duration of temporary clipping is still not well known. The aim of this study is to confirm the safety of precise motor evoked potential (MEP) monitoring and to estimate the permissive duration of temporary clipping for middle cerebral artery (MCA) aneurysm based on precise MEP monitoring results. Under precise MEP monitoring via direct cortical stimulation every 30 seconds to 1 minute, surgeons released a temporary clip and waited for MEP amplitude to recover following severe (>50%) reduction of MEP amplitude during temporary clipping. Precise MEP monitoring was safely performed. Twenty-eight instances of temporary clipping were performed in 42 MCA aneurysm clipping surgeries. Because precise MEP monitoring could be used to determine when to release a temporary clip even with a severe reduction in MEP amplitude due to lengthy temporary clipping, no patients experienced permanent postoperative hemiparesis. Based on logistic regression analysis, if a temporary clip is applied for 312 seconds or more, there is a higher probability of a severe reduction in MEP amplitude. We should therefore release temporary clips after 5 minutes in order to avoid permanent postoperative hemiparesis.

Despite current progress in treatment, glioblastoma (GBM) remains a lethal primary malignant tumor of the central nervous system. Although immunotherapy has recently achieved remarkable survival effectiveness in multiple malignancies, none of the immune checkpoint inhibitors (ICIs) for GBM have shown anti-tumor efficacy in clinical trials. GBM has a characteristic immunosuppressive tumor microenvironment (TME) that results in the failure of ICIs. Oncolytic herpes simplex virotherapy (oHSV) is the most advanced United States Food and Drug Administration-approved virotherapy for advanced metastatic melanoma patients. Recently, another oHSV, Delytact®, was granted conditional approval in Japan against GBM, highlighting it as a promising treatment. Since oncolytic virotherapy can recruit abundant immune cells and modify the immune TME, oncolytic virotherapy for immunologically cold GBM will be an attractive therapeutic option for GBM. However, as these immune cells have roles in both anti-tumor and anti-viral immunity, fine-tuning of the TME using oncolytic virotherapy will be important to maximize the therapeutic efficacy. In this review, we discuss the current knowledge of oHSV, with a focus on the role of immune cells as friend or foe in oncolytic virotherapy.

Background: Iron is an essential element for maintaining vascular wall, however iron depositions in vascular wall cause tissue damage by oxidative stress via Fenton/Haber-Weiss reaction. We hypothesized that iron promotes intracranial aneurysmal formation and rupture through oxidative stress and vascular inflammation. Using a mouse model of intracranial aneurysm, we examined whether iron restriction reduces aneurysm formation and rupture. Methods: To induce aneurysm, we combined induced systemic hypertension (deoxycorticosterone acetate-salt hypertension) and a single injection of elastase (35mU) into the cerebrospinal fluid at the right basal cistern. The mice were divided into two groups and fed with iron restricted diet (IRD) (0.32mg/100g) or normal diet (ND) (600mg/100g) for 5 weeks. Results: IRD significantly reduced the aneurysmal rupture compared to ND (ND versus IRD: 76% versus 37%; P < 0.05). Whereas, there was no significant difference in the overall incidence of aneurysms between the ND and IRD groups (ND versus IRD: 68% versus 69%; P =1.00). Conclusion: Our data demonstrate that iron restriction reduces intracranial aneurysm rupture.

IntroductionMultidrug chemoimmunotherapy with rituximab, high-dose methotrexate, procarbazine and vincristine (R-MPV) is a standard therapy for younger patients with primary central nervous system lymphoma (PCNSL); however, prospective data regarding its use in elderly patients are lacking. This multi-institutional, non-randomised, phase II trial will assess the efficacy and safety of R-MPV and high-dose cytarabine (HD-AraC) for geriatric patients with newly diagnosed PCNSL.Methods and analysisForty-five elderly patients will be included. If R-MPV does not achieve complete response, the patients will undergo reduced-dose, whole-brain radiotherapy comprising 23.4 Gy/13 fractions, followed by local boost radiotherapy comprising 21.6 Gy/12 fractions. After achieving complete response using R-MPV with or without radiotherapy, the patients will undergo two courses of HD-AraC. All patients will undergo baseline geriatric 8 (G8) assessment before HD-AraC and after three, five and seven R-MPV courses. Patients with screening scores of ≥14 points that decrease to Ethics and disseminationThis study complies with the latest Declaration of Helsinki. Written informed consent will be obtained. All participants can quit the study without penalty or impact on treatment. The protocol for the study, statistical analysis plan and informed consent form have been approved by the Certified Review Board at Hiroshima University (CRB6180006) (approval number: CRB2018-0011). The study is ongoing within nine tertiary and two secondary hospitals in Japan. The findings of this trial will be disseminated through national and international presentations and peer-reviewed publications.Trial registrationjRCTs061180093.

Herpes simplex virus thymidine kinase (HSVTK)/ganciclovir (GCV) suicide gene therapy has a long history of treating malignant gliomas. Recently, stem cells from human exfoliated deciduous teeth (SHED), which are collected from deciduous teeth and have excellent harvestability, ethical aspects, and self-renewal, have been attracting attention mainly in the field of gene therapy. In the present study, we assessed SHED as a novel cellular vehicle for suicide gene therapy in malignant gliomas, as we have previously demonstrated with various cell types. SHED was transduced with the HSVTK gene (SHEDTK). In vitro experiments showed a significant bystander effect between SHEDTK and glioma cell lines in coculture. Furthermore, apoptotic changes caused by caspase 3/7 activation were simultaneously observed in SHEDTK and glioma cells. Mice implanted with a mixture of U87 and SHEDTK and treated with intraperitoneal GCV survived for longer than 100 days. Additionally, tumors in treatment model mice were significantly reduced in size during the treatment period. SHEDTK implanted at the contralateral hemisphere migrated toward the tumor crossing the corpus callosum. These results suggested that SHEDTK-based suicide gene therapy has potent tumor tropism and a bystander-killing effect, potentially offering a new promising therapeutic modality for malignant gliomas.

BACKGROUND Robotic technology is increasingly used in neurosurgery. The authors reported a new technique for fence-post tube placement using robot-guided frameless stereotaxic technology with neuronavigation in patients with glioma. OBSERVATIONS Surgery was performed using the StealthStation S8 linked to the Stealth Autoguide cranial robotic guidance platform and a high-resolution three-dimensional (3D) surgical microscope. A surgical plan was created to determine the removal area using fence-post tube placement at the tumor and normal brain tissue boundary. Using this surgical plan, the robotic system allowed quick and accurate fence-post tube positioning, automatic alignment of the needle insertion and measurement positions in the brain, and quick and accurate puncture needle insertion into the brain tumor. Use of a ventricular drainage tube for the outer needle cylinder allowed placement of the puncture needle in a single operation. Furthermore, use of a high-resolution 3D exoscope allowed the surgeon to simultaneously view the surgical field image and the navigation screen with minimal line-of-sight movement, which improved operative safety. The position memory function of the 3D exoscope allowed easy switching between the exoscope and the microscope and optimal field of view adjustment. LESSONS Fence-post tube placement using robot-guided frameless stereotaxic technology, neuronavigation, and an exoscope allows precise glioma resection.

Background Little is known about the antineoplastic effect and the mechanism of Stearoyl-CoA desaturase (SCD) inhibitor which catalyzes the biosynthesis of monounsaturated fatty acids (MUFA). Mutant isocitrate dehydrogenase (IDH) catalyzes the NADPH-mediated reduction of α-ketoglutarate (αKG) to 2-hydroxyglutarate (2HG) and causes metabolic reprograming of lipid. In this study, to develop a feasible drug for IDH mutant glioma, we have investigated the changes of the lipid distribution and the mechanism of antineoplastic effect of SCD inhibition in IDH mutant glioma. Materials and Methods We prepared genetically engineered glioma cell lines (U251 wild type: U251WT and U251 IDH mutant: U251mut) and patient derived cell lines (TS603 and GSC923). Lipid metabolic analysis was conducted by using Raman imaging spectroscopy and LC-MS, and functional analysis for the role of SCD expression in IDH mutant glioma was investigated by RNA sequence and Western-blotting. Results: In LC-MS analysis of the extracted Endoplasmic Reticulum, MUFAs were distributed significantly higher in IDH mutant than wild type. SCD expression was increased in IDH mutant compared to wild type due to 2HG-mediated upregulation of SCD. Therefore, IDH mutant in which SCD expression level was high indicated high sensitivity to SCD inhibitor, and apoptosis was highly induced in IDH mutant compared to wild type. RNA sequencing was performed in U251mut treated with SCD inhibitor compared to U251mut treated with DMSO, and lipid droplet metabolism-associated RNA expression was significantly changed in U251mut treated with SCD inhibitor. We checked lipid droplet in U251mut with presence or absence of SCD inhibitor, and lipolysis was induced by SCD inhibitor treatment, suggesting that SCD inhibition is associated with the apoptosis in IDH mutant via enhanced lipolysis mechanism. Conclusions 2HG produced in IDH mutant glioma directly induces SCD expression and enhances sensitivity to SCD inhibitor, which suggests that SCD inhibitor is an IDH mutant glioma-specific treatment strategy.

Introduction We investigated HSVTK/GCV suicide gene therapy for malignant glioma, and demonstrated the migration ability and antitumor effect of various tissue-derived pluripotent stem cells. In recent years, stem cells from human exfoliated deciduous teeth (SHED), which have excellent ethical and self-renewal ability, have attracted attention, especially in regenerative medicine. In this study, using SHEDTK transfected with TK, we examined the migration ability and antitumor effect against malignant glioma and metastasis models. Methods In vitro assay: Using Matrigel chamber, the migration ability of SHEDTK to conditioned medium (CM) of glioma cells, lung carcinoma cells, and various tumor growth factors (TGF) was examined. The antitumor effect was examined for cell viability by co-culturing SHEDTK and each tumor cell under the addition of GCV. in vivo assay: Using glioma model mice, SHEDTK migrating around the tumor was confirmed in brain sections. In addition, we co-implanted SHEDTK and administered GCV to glioma and metastasis model as therapeutic models, evaluated tumor reduction effect by bioluminescence, and confirmed survival curves. Results In vitro assay: SHEDTK significantly migrated to CM and TGF compared to control. The antitumor effect was observed even when the ratio of each tumor cell to SHEDTK was 128-256 times. in vivo assay: In glioma model mice, SHEDTK migrated around contralateral tumor. In the treatment experiment, the control group died of tumors, whereas the tumor in the treatment group disappeared within the period of GCV administration, and they survived without neurological deficits until 100 days later, and the overall survival time was improved with a statistically significant difference. Conclusions We confirmed the migration ability and antitumor effect of SHEDTK on malignant glioma and metastasis models. Suicide gene therapy using SHEDTK was suggested as novel gene therapy. In the future, we plan to conduct translational research such as preclinical studies and physician -initiated clinical trials.

Background Germinoma preferentially occurs in pediatric and young adult age groups. Although they are responsive to treatment with chemotherapy and radiation, the treatment may cause long-term sequelae in their later lives. Here, we searched for clinical and histopathological features to predict the prognosis of germinoma and affect treatment response. Methods A total of 114 germinoma cases were included in the analysis. We investigated the association between clinical factors, tumor cell content, and progression-free survival (PFS). Results The tumor cell content was widely distributed from Conclusions We found that tumor cell content significantly affected the prognosis of germinomas. Although validation of these results using an independent and larger cohort is necessary, this potentially opens the possibility of leveraging this pathological factor in future clinical trials when stratifying the treatment intensity.

Methotrexate (MTX) is an immunosuppressor that is widely used to treat autoimmune diseases, including rheumatoid arthritis (RA). However, it can have serious adverse effects including a lymphoma: MTX-associated lymphoproliferative disorder (MTX-LPD). Extranodal lesions are common in MTX-LPD patients. However, MTX-LPD in the central nervous system (CNS) is extremely rare with few reported cases. Here, we describe a case of primary CNS MTX-LPD in a patient with RA, with a review of the literature. A 68-year-old woman who had received MTX for her RA for more than 10 years was referred to our hospital. Head magnetic resonance imaging (MRI) showed multiple lesions with heterogeneous contrast enhancement scattered throughout both hemispheres. As immunosuppression caused by MTX was suspected, MTX was discontinued, based on a working diagnosis of MTX-LPD. We performed an open biopsy of her right temporal lesion. Histopathologic examination showed atypical CD20+ lymphoid cells, leading to a definitive diagnosis of diffuse large B-cell lymphoma (DLBCL). In situ hybridization of an Epstein-Barr virus-encoded small RNA (EBER) was positive. Sanger sequencing confirmed that both MYD88 L265 and CD79B Y196 mutations were absent. The LPD regressed after stopping MTX. Follow-up head MRI at 8 months after surgery showed no evidence of recurrence. Although primary CNS MTX-LPD is extremely rare, it should be included in the differential diagnosis when a patient receiving MTX develops CNS lesions. Diagnosis by biopsy and MTX discontinuation are required as soon as possible.