While molecular subgrouping has revolutionized medulloblastoma classification, the extent of heterogeneity within subgroups is unknown. Similarity network fusion (SNF) applied to genome-wide DNA methylation and gene expression data across 763 primary samples identifies very homogeneous clusters of patients, supporting the presence of medulloblastoma subtypes. After integration of somatic copy-number alterations, and clinical features specific to each cluster, we identify 12 different subtypes of medulloblastoma. Integrative analysis using SNF further delineates group 3 from group 4 medulloblastoma, which is not as readily apparent through analyses of individual data types. Two clear subtypes of infants with Sonic Hedgehog medulloblastoma with disparate outcomes and biology are identified. Medulloblastoma subtypes identified through integrative clustering have important implications for stratification of future clinical trials.

Over the past decade, wingless-activated (WNT) medulloblastoma has been identified as a candidate for therapy de-escalation based on excellent survival; however, a paucity of relapses has precluded additional analyses of markers of relapse. To address this gap in knowledge, an international cohort of 93 molecularly confirmed WNT MB was assembled, where 5-year progression-free survival is 0.84 (95%, 0.763-0.925) with 15 relapsed individuals identified. Maintenance chemotherapy is identified as a strong predictor of relapse, with individuals receiving high doses of cyclophosphamide or ifosphamide having only one very late molecularly confirmed relapse (p = 0.032). The anatomical location of recurrence is metastatic in 12 of 15 relapses, with 8 of 12 metastatic relapses in the lateral ventricles. Maintenance chemotherapy, specifically cumulative cyclophosphamide doses, is a significant predictor of relapse across WNT MB. Future efforts to de-escalate therapy need to carefully consider not only the radiation dose but also the chemotherapy regimen and the propensity for metastatic relapses.

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.

Ring finger protein 213 (RNF213) is a susceptibility gene of moyamoya disease (MMD). A previous case-control study and a family analysis demonstrated a strong association of the East Asian-specific variant, R4810K (rs112735431), with MMD. Our aim is to uncover evolutionary history of R4810K in East Asian populations.

In cancer, recurrent somatic single-nucleotide variants-which are rare in most paediatric cancers-are confined largely to protein-coding genes1-3. Here we report highly recurrent hotspot mutations (r.3A>G) of U1 spliceosomal small nuclear RNAs (snRNAs) in about 50% of Sonic hedgehog (SHH) medulloblastomas. These mutations were not present across other subgroups of medulloblastoma, and we identified these hotspot mutations in U1 snRNA in only <0.1% of 2,442 cancers, across 36 other tumour types. The mutations occur in 97% of adults (subtype SHHδ) and 25% of adolescents (subtype SHHα) with SHH medulloblastoma, but are largely absent from SHH medulloblastoma in infants. The U1 snRNA mutations occur in the 5' splice-site binding region, and snRNA-mutant tumours have significantly disrupted RNA splicing and an excess of 5' cryptic splicing events. Alternative splicing mediated by mutant U1 snRNA inactivates tumour-suppressor genes (PTCH1) and activates oncogenes (GLI2 and CCND2), and represents a target for therapy. These U1 snRNA mutations provide an example of highly recurrent and tissue-specific mutations of a non-protein-coding gene in cancer.

This study explored the superiority of temozolomide (TMZ) + interferonβ (IFNβ) to standard TMZ as treatment for newly diagnosed glioblastoma (GBM) via randomized phase II screening design.

Isocitrate dehydrogenase 1/2 (IDH1/2) mutations have been detected in gliomas, cartilaginous tumors, and leukemias. IDH1/2 mutations are early and frequent genetic alterations, are specific to a single codon in the conserved and functionally important Arginine 132 (R132) in IDH1 and Arginine 172 (R172) in IDH2. We previously established several monoclonal antibodies (mAbs), which are specific for IDH1 mutations: clones IMab-1 or HMab-1 against IDH1-R132H or clone SMab-1 against IDH1-R132S. However, specific mAbs against IDH2 mutations have not been reported. To establish IDH2-mutation-specific mAbs, we immunized mice or rats with each mutation-containing IDH2 peptides including IDH2-R172K and IDH2-R172M. After cell fusion, IDH2 mutation-specific mAbs were screened in Enzyme-Linked Immunosorbent Assay (ELISA). Established mAbs KMab-1 and MMab-1 reacted with the IDH2-R172K and IDH2-R172M peptides, respectively, but not with IDH2-wild type (WT) in ELISA. Western-blot analysis also showed that KMab-1 and MMab-1 reacted with the IDH2-R172K and IDH2-R172M recombinant proteins, respectively, not with IDH2-WT or other IDH2 mutants, indicating that KMab-1 and MMab-1 are IDH2-mutation-specific. Furthermore, MMab-1 specifically stained the IDH2-R172M-expressing cells in immunocytochemistry, but did not stain IDH2-WT and other IDH2-mutation-containing cells. In immunohistochemical analysis, MMab-1 specifically stained IDH2-R172M-expressing glioma. This is the first report to establish anti-IDH2-mutation-specific mAbs, which could be useful in diagnosis of mutation-bearing tumors.

The majority of supratentorial ependymomas (ST-ependymomas) have few mutations but frequently display chromothripsis of chromosome 11q that generates a fusion between C11orf95 and RELA (RELAFUS). Neural stem cells transduced with RELAFUSex vivo form ependymomas when implanted in the brain. These tumors display enhanced NF-κB signaling, suggesting that this aberrant signal is the principal mechanism of oncogenesis. However, it is not known whether RELAFUS is sufficient to drive de novo ependymoma tumorigenesis in the brain and, if so, whether these tumors also arise from neural stem cells. We show that RELAFUS drives ST-ependymoma formation from periventricular neural stem cells in mice and that RELAFUS-induced tumorigenesis is likely dependent on a series of cell signaling pathways in addition to NF-κB.

To analyze a specific genome region using next-generation sequencing technologies, the enrichment of DNA libraries with targeted capture methods has been standardized. For enrichment of mitochondrial genome, a previous study developed an original targeted capture method that use baits constructed from long-range polymerase chain reaction (PCR) amplicons, common laboratory reagents, and equipment. In this study, a new targeted capture method is presented, that of bacterial artificial chromosome (BAC) double capture (BDC), modifying the previous method, but using BAC libraries as baits for sequencing a relatively large gene. We applied the BDC approach for the 214 kb autosomal region, ring finger protein 213, which is the susceptibility gene of moyamoya disease (MMD). To evaluate the reliability of BDC, cost and data quality were compared with those of a commercial kit. While the ratio of duplicate reads was higher, the cost was less than that of the commercial kit. The data quality was sufficiently the same as that of the kit. Thus, BDC can be an easy, low-cost, and useful method for analyzing individual genome regions with substantial length.

Current therapies for medulloblastoma, a highly malignant childhood brain tumour, impose debilitating effects on the developing child, and highlight the need for molecularly targeted treatments with reduced toxicity. Previous studies have been unable to identify the full spectrum of driver genes and molecular processes that operate in medulloblastoma subgroups. Here we analyse the somatic landscape across 491 sequenced medulloblastoma samples and the molecular heterogeneity among 1,256 epigenetically analysed cases, and identify subgroup-specific driver alterations that include previously undiscovered actionable targets. Driver mutations were confidently assigned to most patients belonging to Group 3 and Group 4 medulloblastoma subgroups, greatly enhancing previous knowledge. New molecular subtypes were differentially enriched for specific driver events, including hotspot in-frame insertions that target KBTBD4 and 'enhancer hijacking' events that activate PRDM6. Thus, the application of integrative genomics to an extensive cohort of clinical samples derived from a single childhood cancer entity revealed a series of cancer genes and biologically relevant subtype diversity that represent attractive therapeutic targets for the treatment of patients with medulloblastoma.

Pediatric astrocytomas, a leading cause of death associated with cancer, are the most common primary central nervous system tumors found in children. Most studies of these tumors focus on adults, not on children. We examined the global protein and microRNA expression pattern by 2D SDS-PAGE, mass spectrometry (MALDI-TOF), and RT(2) miRNA PCR Array System. Proteomic studies revealed 49 proteins with changes on the expression. Interactome showed that vimentin, calreticulin, and 14-3-3 epsilon protein are hub proteins in these neoplasms. MicroRNA analyses demonstrated for the first time novel microRNAs involved in the astrocytoma biology. In conclusion, our results show that novel proteins and microRNAs with expression changes on pediatric astrocytoma could serve as biomarkers of tumor progression.

Patients with incomplete surgical resection of medulloblastoma are controversially regarded as having a marker of high-risk disease, which leads to patients undergoing aggressive surgical resections, so-called second-look surgeries, and intensified chemoradiotherapy. All previous studies assessing the clinical importance of extent of resection have not accounted for molecular subgroup. We analysed the prognostic value of extent of resection in a subgroup-specific manner.

Glioblastoma is the most malignant human brain tumor and has a dismal prognosis; however, some patients show long-term survival. The interaction between the costimulatory molecule OX40 and its ligand OX40L generates key signals for T-cell activation. The augmentation of this interaction enhances antitumor immunity. In this present study, we explored whether OX40 signaling is responsible for antitumor adaptive immunity against glioblastoma and also established therapeutic antiglioma vaccination therapy.

This retrospective study was aimed to compare the perioperative complications for internal carotid artery stenosis (ICS) in a Japanese single institute between the use of carotid artery stenting (CAS) alone or the use of an appropriate individualized treatment method allowing either carotid endarterectomy (CEA) or CAS based on patient risk factors. Based on the policy at our hospital, only CAS was performed on patients (n = 33) between January 2005 and November 2009. From December 2009 to December 2012, either CEA or CAS (tailored treatment) was selected for patients (n = 61) based on individual patient risk factors. CEA was considered the first-line treatment in all cases. In high-risk CEA cases, CAS was performed instead (n = 11), whereas in low-risk CEA cases, CEA was performed (n = 19). Further, in moderate-risk CEA cases based on own criteria, CAS was considered first, whereas for high-risk CAS cases, CEA was performed (n = 17). For low-risk CAS cases, CAS was performed (n = 9). Perioperative clinical complications (any stroke, myocardial infarction, or death within 30 days) were compared between both periods. Significantly reduced perioperative complications were observed during the tailored period (4/61 sites, 6.6%) as compared with the CAS period (8/33 sites, 24.2%) [Fisher's exact test p = 0.022; odds ratio, 4.56 (CAS/tailored); 95% confidence interval, 1.26-16.5]. Selecting an appropriate individualized treatment method according to patient risk factors, as opposed to adhering to a single treatment approach such as CAS, may contribute to improved overall outcomes in patients with ICS.

Sonic hedgehog medulloblastoma encompasses a clinically and molecularly diverse group of cancers of the developing central nervous system. Here, we use unbiased sequencing of the transcriptome across a large cohort of 250 tumors to reveal differences among molecular subtypes of the disease, and demonstrate the previously unappreciated importance of non-coding RNA transcripts. We identify alterations within the cAMP dependent pathway (GNAS, PRKAR1A) which converge on GLI2 activity and show that 18% of tumors have a genetic event that directly targets the abundance and/or stability of MYCN. Furthermore, we discover an extensive network of fusions in focally amplified regions encompassing GLI2, and several loss-of-function fusions in tumor suppressor genes PTCH1, SUFU and NCOR1. Molecular convergence on a subset of genes by nucleotide variants, copy number aberrations, and gene fusions highlight the key roles of specific pathways in the pathogenesis of Sonic hedgehog medulloblastoma and open up opportunities for therapeutic intervention.

Although mutations in the promoter region of the telomerase reverse transcriptase (TERTp) gene are the most common alterations in glioblastoma (GBM), their clinical significance remains unclear. Therefore, we investigated the impact of TERTp status on patient outcome and clinicopathological features in patients with GBM over a long period of follow-up.

Thalamic high-grade gliomas (HGGs) are rare tumors with a dismal prognosis. H3K27M and telomerase reverse transcriptase promoter (TERTp) mutations reportedly contribute to poor prognoses in HGG cases. We investigated the outcomes of surgically treated adult thalamic HGGs to evaluate the prognostic significance of H3K27M and TERTp mutations.

Resection of insulo-opercular gliomas carries the risk of postoperative hemiparesis caused by ischemia of the corona radiata resulting from injury to the long insular arteries. However, intraoperative identification of these perforating arteries is challenging. We attempted intra-operative motor evoked potential (MEP) monitoring under temporary occlusion of the suspected long insular artery arising from the opercular portion of middle cerebral artery in two patients with insulo-opercular gliomas. Temporary occlusion of the artery caused decrease in MEP amplitude, which recovered after release in one patient, who had no postoperative motor deficits or ischemic lesion in the corona radiata. Temporary occlusion of the artery caused no changes in MEP amplitude, so that the artery was sacrificed for tumor removal in the other patient, who had no motor deficits but ischemic lesion was present in the corona radiata in the territory of the long insular artery sparing the descending motor pathway. These cases show that great care should be taken during surgical manipulations near the posterior part of the superior limiting sulcus to preserve the perforating branches to the corona radiata, and temporary occlusion of the branches under MEP monitoring is useful to identify the arteries supplying the pyramidal tract.

Brain radiation necrosis (BRN) can be a complication of radiotherapy for primary and secondary brain tumors, as well as head and neck tumors. Since vascular endothelial growth factor (VEGF) is also a vascular permeability factor in the brain, bevacizumab, a humanized antibody that inhibits VEGF, would be expected to reduce perilesional edema that often accompanies BRN.

TP53 mutations confer subgroup specific poor survival for children with medulloblastoma. We hypothesized that WNT activation which is associated with improved survival for such children abrogates TP53 related radioresistance and can be used to sensitize TP53 mutant tumors for radiation. We examined the subgroup-specific role of TP53 mutations in a cohort of 314 patients treated with radiation. TP53 wild-type or mutant human medulloblastoma cell-lines and normal neural stem cells were used to test radioresistance of TP53 mutations and the radiosensitizing effect of WNT activation on tumors and the developing brain. Children with WNT/TP53 mutant medulloblastoma had higher 5-year survival than those with SHH/TP53 mutant tumours (100% and 36.6%±8.7%, respectively (p<0.001)). Introduction of TP53 mutation into medulloblastoma cells induced radioresistance (survival fractions at 2Gy (SF2) of 89%±2% vs. 57.4%±1.8% (p<0.01)). In contrast, β-catenin mutation sensitized TP53 mutant cells to radiation (p<0.05). Lithium, an activator of the WNT pathway, sensitized TP53 mutant medulloblastoma to radiation (SF2 of 43.5%±1.5% in lithium treated cells vs. 56.6±3% (p<0.01)) accompanied by increased number of γH2AX foci. Normal neural stem cells were protected from lithium induced radiation damage (SF2 of 33%±8% for lithium treated cells vs. 27%±3% for untreated controls (p=0.05). Poor survival of patients with TP53 mutant medulloblastoma may be related to radiation resistance. Since constitutive activation of the WNT pathway by lithium sensitizes TP53 mutant medulloblastoma cells and protect normal neural stem cells from radiation, this oral drug may represent an attractive novel therapy for high-risk medulloblastomas.