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Glioblastomas (GBMs), the most common primary brain tumor in adults, are characterized by resistance to chemotherapy and radiotherapy. One of the defining characteristics of GBM is an abundant and aberrant vasculature. The processes of vascular co-option, angiogenesis, and vasculogenesis in gliomas have been extensively described. Recently, however, it has become clear that these three processes are not the only mechanisms by which neovascularization occurs in gliomas. Furthermore, it seems that these processes interact extensively, with potential overlap among them. At least five mechanisms by which gliomas achieve neovascularization have been described: vascular co-option, angiogenesis, vasculogenesis, vascular mimicry, and (the most recently described) glioblastoma-endothelial cell transdifferentiation. We review these mechanisms in glioma neovascularization, with a particular emphasis on the roles of hypoxia and glioma stem cells in each process. Although some of these processes are well established, others have been identified only recently and will need to be further investigated for complete validation. We also review strategies to target glioma neovascularization and the development of resistance to these therapeutic strategies. Finally, we describe how these complex processes interlink and overlap. A thorough understanding of the contributing molecular processes that control the five modalities reviewed here should help resolve the treatment resistance that characterizes GBMs.

Oncogenic TACC-tics Human cancers exhibit many types of genomic rearrangements—including some that juxtapose sequences from two unrelated genes—thereby creating fusion proteins with oncogenic activity. Functional analysis of these fusion genes can provide mechanistic insights into tumorigenesis and potentially lead to effective drugs, as famously illustrated by the BCR-ABL gene in chronic myelogenous leukemia. Singh et al. (p. 1231 , published online 26 July) identify and characterize a fusion gene present in 3% of human glioblastomas, a deadly brain cancer. In the resultant fusion protein, the tyrosine kinase region of the fibroblast growth factor receptor (FGFR) is joined to a domain from a transforming acidic coiled-coil (TACC) protein. The TACC-FGFR protein is oncogenic, shows unregulated kinase activity, localizes to the mitotic spindle, and disrupts chromosome segregation. In mice, FGFR inhibitors slowed the growth of tumors driven by the TACC-FGFR gene, suggesting that a subset of glioblastoma patients may benefit from these types of drugs.

Glutamic acid decarboxylase (GAD) is the rate-limiting enzyme converting glutamate into γ-aminobutyric acid. Impaired GAD function can alter motor, cognitive, and behavioral function. Anti-GAD antibodies (GADAbs) can cause several neurological disorders. However, the association between anti-GADAbs and pure psychosis, without seizures or focal neurological deficits, is not well defined.A 19-year-old woman with recent-onset psychotic disorder was diagnosed with schizophrenia. Brain magnetic resonance imaging and cerebrospinal fluid analysis were normal. Serum anti-GADAb titers were elevated. Brain biopsy showed subcortical gliosis and microglia-macrophage infiltration. The clinical syndrome improved with immune therapy.Severe psychosis and mild cognitive decline without other neurological features, meeting the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision diagnostic criteria for schizophrenia, can result from brain inflammation associated with elevated serum anti-GADAbs.

Object The presence of angiogenesis is a hallmark of glioblastoma (GBM). Vascular endothelial growth factor (VEGF), which drives angiogenesis, provides an additional target for conventional therapy. The authors conducted a prospective clinical trial to test the effectiveness of bevacizumab, an inhibitor of VEGF, in newly diagnosed GBM. Methods From 2006 through 2010, 51 eligible patients with newly diagnosed GBM were treated with involved-field radiation therapy and concomitant temozolomide (75 mg/m2 daily for 42 days) along with bevacizumab (10 mg/kg every 2 weeks), starting 29 days after surgery. This was followed by 6 cycles of adjuvant temozolomide therapy (150 mg/m2 on Days 1–7 of a 28-day cycle) with bevacizumab administered at 10 mg/kg on Days 8 and 22 of each 28-day cycle. Results The 6- and 12-month progression-free survival (PFS) rates were 85.1% and 51%, respectively. The 12- and 24-month overall survival (OS) rates were 85.1% and 42.5%, respectively. Grade III/IV toxicities were noted in 10 patients (19.6%). No treatment-related deaths were observed. Asymptomatic intracranial bleeding was noted in 5 patients. Conclusions The addition of bevacizumab to conventional therapy in newly diagnosed GBM appears to improve both PFS and OS in patients with newly diagnosed GBM, with acceptable morbidity. A shift toward diffuse relapse was noted in a significant number of patients. Ongoing Phase III clinical trials will show the true benefit of this antiangiogenic approach.

Recent studies highlight the importance of BRAF alterations resulting in mitogen activated protein kinase (MAK/ERK) pathway activation in low-grade CNS tumors. We studied 106 low-grade CNS neoplasms in a cohort of primarily pediatric patients to identify the prevalence and clinicopathologic significance of these alterations. Polymerase chain reaction testing identified KIAA1549:BRAF fusions in 51 (48%) tumors overall, including 42 (60%) pilocytic astrocytomas, 4 (17%) unclassifiable low-grade gliomas, 4 (36%) low-grade glioneuronal/neuroepithelial tumors, 0 (of 5) pleomorphic xanthoastrocytomas, 0 (of 4) diffuse astrocytomas (World Health Organization grade II), and 1 (of 3, 33%) pilomyxoid astrocytoma. KIAA1549:BRAF gene fusions confirmed by sequencing included the previously reported ones involving exons 1–16/9–18 (49%), 1–15/9–18 (35%), and 1–16/11–18 (8%) and 2 fusions with novel breakpoints: 1–15/11–18 (6%) and 1–17/10–18 (1%). DNA sequencing identified BRAFV600E mutations in 8% of tumors. BRAFG468A mutations were absent. KIAA1549:BRAF fusions were significantly more frequent in infratentorial (57%) and optic pathway (59%) tumors versus supratentorial (19%) tumors (p = 0.001). We did not identify significantly improved progression-free survival in tumors with fusions. In summary, KIAA1549:BRAF fusions predominate in pilocytic astrocytomas but are also present in some low-grade unclassifiable gliomas and glioneuronal tumors. The prognostic and therapeutic significance of this alteration is unclear and merits further study.

Cell fusion in vitro has been used to study cancer, gene mapping and regulation, and the production of antibodies via hybridomas. However, in-vivo heterosynkaryon formation by cell-cell fusion has received less attention. This investigation describes the spontaneous fusion of a human glioblastoma with normal hamster cells after xenogeneic transplantation, resulting in malignant cells that express both human and hamster genes and gene products, and retention of glioblastoma traits with an enhanced ability to metastasize. Three of 7 human genes found showed translation of their proteins during serial propagation in vivo or in vitro for years; namely, CD74, CXCR4, and PLAGL2, each implicated with malignancy or glioblastoma. This supports the thesis that genetic hybridization of cancer and normal cells can transmit malignancy and also, as first described herein, regulatory genes involved in the tumor’s organotypic morphology. Evidence also is increasing that even cell-free human cancer DNA can induce malignancy and transfer genetic information to normal cells. Hence, we posit that the transfer of genetic information between tumor and stromal cells, whether by cell-cell fusion or other mechanisms, is implicated in the progression of malignancy, and may further define the crosstalk between cancer cells and their stromal neighbors.

Castleman’s disease (CD) is defined as a non-neoplastic reactive proliferation of lymphoid tissue, also known as angiofollicular lymph node hyperplasia and giant lymph node hyperplasia. Initial identification of this eponymous disease dates back to 1956 [1]. Two distinct histological classifications are described extensively in the literature: hyaline-vascular and plasma cell types [2]. However, remarkable advances have been made in the characterization of CD, including the most recent elaboration of human herpes virus-8 (HHV-8)-related CD [3]. Hyaline-vascular CD is more common than the plasma cell type and usually presents as localized or unicentric disease involving one or several lymph node aggregates. Perhaps the most well recognized manifestation of localized CD presents with avidly enhancing mediastinal adenopathy. Despite what the histology implies, extranodal CD has been documented in multiple locations. In rare instances, extranodal disease may affect the central nervous system (CNS) and bears a remarkably similar appearance to meningioma, both clinically and using various imaging methods (e.g. magnetic resonance imaging and arteriography, [4–10]). In this article a follow-up discourse of a case of intracranial CD is presented which will be a unique addition to the literature [11]. This is the first case of intracranial CD which has been evaluated using an advanced imaging technique, dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI). The goals are two-fold: first to chronicle the initial surgical resection of localized CD of the CNS and to remark on what was strongly felt to represented recurrent perineural spread of the disease in a separate, noncontiguous location; second it is hoped that the role that perfusion MRI may play in characterizing intracranial CD will be illuminated, as the inherent limitations of conventional imaging prevent adequate differentiation between CD of the CNS and more commonly encountered extra-axial lesions (e.g. meningioma).

Rhabdoid tumors (RT) are aggressive pediatric malignancies with poor prognosis. INI1/hSNF5 is a component of the chromatin remodeling SWI/SNF complex and a tumor suppressor deleted in RT. Previous microarray studies indicated that reintroduction of INI1/hSNF5 into RT cells leads to repression of a high degree of mitotic genes including Aurora Kinase A (Aurora A, STK6). Here, we found that INI1/SNF5 represses Aurora A transcription in a cell-type–specific manner. INI1-mediated repression was observed in RT and normal cells but not in non-RT cell lines. Chromatin immunoprecipitation (ChIP) assay indicated that INI1/hSNF5 associates with Aurora A promoter in RT and normal cells but not in non-RT cells. Real-time PCR and immunohistochemical analyses of primary human and mouse RTs harboring mutations in INI1/hSNF5 gene indicated that Aurora A was overexpressed/derepressed in these tumor cells, confirming that INI1/hSNF5 represses Aurora A in vivo. Knockdown of Aurora A impaired cell growth, induced mitotic arrest and aberrant nuclear division leading to decreased survival, and increased cell death and caspase 3/7-mediated apoptosis in RT cells (but not in normal cells). These results indicated that Aurora A is a direct downstream target of INI1/hSNF5-mediated repression in RT cells and that loss of INI1/hSNF5 leads to aberrant overexpression of Aurora A in these tumors, which is required for their survival. We propose that a high degree of Aurora A expression may play a role in aggressive behavior of RTs and that targeting expression or activity of this gene is a novel therapeutic strategy for these tumors. Cancer Res; 71(9); 3225–35. ©2011 AACR.

INTRODUCTION: Identification of IDH1/2 mutations and association with better outcome revolutionized diagnosis and management of patients with gliomas. Liquid biopsy can detect driver mutation from blood, however, detection of circulating tumor DNA or circulating tumor cells from patients with brain tumors is difficult due to the low amount of circulating tumor material in the peripheral blood. We hypothesized that brain tumors alter the epigenetic profiles of circulating leukocytes and sought to identify specific methylation patterns in peripheral blood that would identify molecular subtypes of gliomas. METHODS: We analyzed brain tumors and matched whole peripheral blood collected in EDTA tubes from 63 patients with primary gliomas. Tumor IDH1/2 mutation status was analyzed using next-generation sequencing and DNA methylation was analyzed using Illumina Human EPIC array. A complete blood count with differential (CBC) was analyzed to control for variations in CBC profiles. Peripheral blood methylation profile was compared to blood of 40 individuals with no known history of brain tumors. DNA methylation of Acute Myeloid Leukemia (AML) samples (source: TCGA) was used to identify overlapping DNA methylation changes induced by IDH1/2 mutations. Methylation data were analyzed with the R Bioconductor package minfi, including quality control, data normalization and differentially methylated CpG site analysis. Subsequent filtering was performed using a p-value cutoff = 0.01 and a minimal mean difference of the Beta-value of 0.1. RESULTS: Peripheral blood methylation profiles of patients with brain tumors are distinctly different from normal controls. DNA methylation of IDH1/2 mutated brain tumors and AML showed significant overlap (enrichment = 3, p-value 2.2x10-16) and DNA methylation of IDH1/2 mutated AML cells showed significant overlap with circulating leukocytes from patients with IDH1/2 mutated brain tumors (enrichment = 6.5, p-value 2.2x10-8 ). Using this classifier supported by AML data, DNA methylation of circulating leukocytes was able to predict IDH1/2 mutation status of diffuse gliomas with 98% accuracy, nearly perfectly separating IDH status by clustering. CONCLUSIONS: Diffuse gliomas induce epigenetic changes in the methylome of the leukocytes, which resembles methylation changes of IDH1/2 mutated AML. IDH wildtype and mutant gliomas can be distinguished with high accuracy by profiling the epigenome of leukocytes. Our study demonstrates the potential of peripheral blood DNA methylation assessment for non-invasive diagnosis of brain tumors. Citation Format: Andreas Kloetgen, Jonathan Serrano, Seema Patel, Christopher Bowman, Guomiao Shen, David Zagzag, Matthias A. Karajannis, John G. Golfinos, Dimitris Placantonakis, Aristotelis Tsirigos, Andrew S. Chi, Matija Snuderl. DNA methylation of circulating tumor educated leukocytes predicts IDH1/2 mutation status in adult patients with diffuse gliomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3658.

Invasion is a hallmark of malignant gliomas and is the main reason for therapeutic failure and recurrence of the tumor. CXCR4 is a key chemokine receptor implicated in glioma cell migration whose expression is regulated by hypoxia. Here, we report that hepatocyte growth factor (HGF) upregulated CXCR4 protein expression in glioma cells. HGF pre-treatment increased migration of U87MG and LN229 glioma cells towards the CXCR4 ligand, stromal cell-derived factor-1alpha (SDF-1alpha). AMD3100, a CXCR4 inhibitor, inhibited the increased migration of HGF pre-treated LN229 glioma cells towards SDF-1alpha. Following exposure to HGF and hypoxia, both cell lines showed nuclear translocation of NF-kappaB (p65). The HGF- and hypoxia-induced nuclear translocation of NF-kappaB (p65) involved phosphorylation and degradation of IkappaB-alpha. Knock-down of NF-kappaB expression inhibited the induction of CXCR4 expression in response to HGF, but not to hypoxia. However, knock-down of NF-kappaB expression inhibited the induction of CXCR4 expression in response to hypoxia in the presence of HGF. NF-kappaB mediated migration towards SDF-1alpha in response to HGF. Knock-down of NF-kappaB expression resulted in decreased migration of HGF pre-treated glioma cells towards SDF-1alpha. Therefore, HGF upregulates CXCR4 expression via NF-kappaB and leads to enhanced migration. To our knowledge, this is the first report to show that a crosstalk mediated by NF-kappaB exists between the SDF-1alpha/CXCR4 and HGF/c-Met axes relevant to glioma cell migration. These findings imply that effective inhibition of glioma invasion should be directed against several ligand/receptor signaling pathways.

Vestibular schwannomas (VS) arising sporadically or in patients with neurofibromatosis type 2 (NF2) consistently lack expression of Merlin, a tumor suppressor. Conventional treatment options include surgery and radiotherapy but there is no validated medical option. Recent evidence suggests that Merlin deficiency may result in abnormal activation of receptor tyrosine kinases (RTKs) and downstream signaling, promoting tumor growth. Although small-molecule RTK inhibitors are widely available for clinical use, no such therapy has been validated in patients with VS. To screen for RTK activation, surgical VS specimens from patients with and without NF2 were analyzed by phospho-RTK profiling arrays. Downstream signaling pathway activation was analyzed by phospho-MAPK arrays. Activated RTKs and downstream kinases were validated immunohistochemically in corresponding formalin-fixed, paraffin-embedded tissues. Phospho-RTK arrays and immunohistochemistry showed consistent overexpression and activation of EGFR family receptors and evidence of ERK1/2 downstream signaling was observed in all samples analyzed (n = 11). Based on the findings, the small-molecule EGFR/ErbB2 kinase inhibitor lapatinib was selected for evaluation of target inhibition and treatment efficacy in our in vitro human schwannoma model. EGFR/ErbB2 targeted therapy with lapatinib inhibited ErbB2 phosphorylation and survivin upregulation, as well as downstream ERK1/2 and AKT activation, resulting in decreased proliferation. We conclude that EGFR family receptor activation is a consistent feature of both sporadic and NF2-related VS. Molecular targeted therapy with lapatinib downregulates survivin and has antiproliferative activity in a preclinical VS model. Based on these findings, a clinical trial with lapatinib for the treatment of VS is currently underway.

Background/purpose The prognostic value of defining subcategories of gliomas is still controversial. This study aims to determine the utility of relative cerebral blood volume (rCBV) in predicting clinical response in patients with low-grade glioma at multiple institutions. Materials and methods Sixty-nine patients were studied with dynamic susceptibility contrast-enhanced perfusion MRI at two institutions. The pathologic diagnoses of the low-grade gliomas were 34 astrocytomas, 20 oligodendroglioma, 9 oligoastrocytomas, 1 ganglioglioma and 5 with indeterminate histology. Wilcoxon tests were used to compare patients in different response categories with respect to baseline rCBV. Kaplan–Meier curve and log-rank tests were used to predict the association of rCBV with time to progression. Results At both institutions, patients with an adverse event (progressive disease or death) had a significantly higher baseline rCBV than those without (complete response or stable disease) (p value = 0.0138). The odds ratio for detecting an adverse event when using rCBV was 1.87 (95% confidence interval: 1.14–3.08). rCBV was significantly negatively associated with time to progression (p = 0.005). The median time to progression among subjects with rCBV > 1.75 was 365 days, while there was 95% confidence that the median time to progression was at least 889 days among subjects with rCBV Conclusion Our study suggests not only that rCBV measurements correlate well with time to progression or death, but also that the findings can be replicated across institutions, which supports the application of rCBV as an adjunct to pathology in predicting glioma biology.

Subependymal giant cell tumors (SGCTs) are observed in 5–20% of patients with tuberous sclerosis complex (TSC) but account for ~ 25% of neurological morbidity. The authors report the case of a 7-year-old girl with TSC and multiple cortical tubers who presented with worsening seizures in the context of the rapid growth of a cystic, calcified, extraventricular SGCT in the right frontal lobe, initially thought to represent a cortical tuber. The tumor and surrounding tubers were excised, and clinical seizures resolved. This is the first report of an extraventricular SGCT in a child with TSC outside the neonatal period.

T-cell acute lymphoblastic leukaemia (T-ALL) is a blood malignancy afflicting mainly children and adolescents1. T-ALL patients present at diagnosis with increased white cell counts and hepatosplenomegaly, and are at an increased risk of central nervous system (CNS) relapse2,3. For that reason, T-ALL patients usually receive cranial irradiation in addition to intensified intrathecal chemotherapy. The marked increase in survival is thought to be worth the considerable side-effects associated with this therapy. Such complications include secondary tumours, neurocognitive deficits, endocrine disorders and growth impairment3. Little is known about the mechanism of leukaemic cell infiltration of the CNS, despite its clinical importance4. Here we show, using T-ALL animal modelling and gene-expression profiling, that the chemokine receptor CCR7 (ref. 5) is the essential adhesion signal required for the targeting of leukaemic T-cells into the CNS. Ccr7 gene expression is controlled by the activity of the T-ALL oncogene Notch1 and is expressed in human tumours carrying Notch1-activating mutations. Silencing of either CCR7 or its chemokine ligand CCL19 (ref. 6) in an animal model of T-ALL specifically inhibits CNS infiltration. Furthermore, murine CNS-targeting by human T-ALL cells depends on their ability to express CCR7. These studies identify a single chemokine–receptor interaction as a CNS ‘entry’ signal, and open the way for future pharmacological targeting. Targeted inhibition of CNS involvement in T-ALL could potentially decrease the intensity of CNS-targeted therapy, thus reducing its associated short- and long-term complications.

Object Antiangiogenic agents have recently shown impressive radiological responses in high-grade glioma. However, it is not clear if the responses are related to vascular changes or due to antitumoral effects. The authors report the mature results of a clinical study of bevacizumab-based treatment of recurrent high-grade gliomas. Methods Sixty-one patients with recurrent high-grade gliomas received treatment with bevacizumab at 10 mg/ kg every 2 weeks for 4 doses in an 8-week cycle along with either irinotecan or carboplatin. The choice of concomitant chemotherapeutic agent was based on the number of recurrences and prior chemotherapy. Results At a median follow-up of 7.5 months (range 1–19 months), 50 (82%) of 61 patients relapsed and 42 patients (70%) died of the disease. The median number of administered bevacizumab cycles was 2 (range 1–7 cycles). The median progression-free survival (PFS) and overall survival (OS) were 5 (95% confidence interval [CI] 2.3–7.7) and 9 (95% CI 7.6–10.4) months, respectively, as calculated from the initiation of the bevacizumab-based therapy. Radiologically demonstrated responses following therapy were noted in 73.6% of cases. Neither the choice of chemotherapeutic agent nor the performance of a resection prior to therapy had an impact on patient survival. Although the predominant pattern of relapse was local, 15 patients (30%) had diffuse disease. Conclusions Antiangiogenic therapy using bevacizumab appears to improve survival in patients with recurrent high-grade glioma. A possible change in the invasiveness of the tumor following therapy is worrisome and must be closely monitored.

We evaluate the effects of adjuvant treatment with the angiogenesis inhibitor Avastin (bevacizumab) on pathological tissue specimens of high-grade glioma. Tissue from five patients before and after treatment with Avastin was subjected to histological evaluation and compared to four control cases of glioma before and after similar treatment protocols not including bevacizumab. Clinical and radiographic data were reviewed. Histological analysis focused on microvessel density and vascular morphology, and expression patterns of vascular endothelial growth factor–A (VEGF-A) and the hematopoietic stem cell, mesenchymal, and cell motility markers CD34, smooth muscle actin, D2-40, and fascin. All patients with a decrease in microvessel density had a radiographic response, whereas no response was seen in the patients with increased microvessel density. Vascular morphology showed apparent “normalization” after Avastin treatment in two cases, with thin-walled and evenly distributed vessels. VEGF-A expression in tumor cells was increased in two cases and decreased in three and did not correlate with treatment response. There was a trend toward a relative increase of CD34, smooth muscle actin, D2-40, and fascin immunostaining following treatment with Avastin. Specimens from four patients with recurrent malignant gliomas before and after adjuvant treatment (not including bevacizumab) had features dissimilar from our study cases. We conclude that a change in vascular morphology can be observed following anti-angiogenic treatment. There seems to be no correlation between VEGF-A expression and clinical parameters. While the phenomena we describe may not be specific to Avastin, they demonstrate the potential of tissue-based analysis for the discovery of clinically relevant treatment response biomarkers.

The morphological patterns of glioma cell invasion are known as the secondary structures of Scherer. In this report, we propose a biologically based mechanism for the nonrandom formation of Scherer's secondary structures based on the differential expression of stromal cell-derived factor (SDF)-1α and CXCR4 at the invading edge of glioblastomas. The chemokine SDF-1α was highly expressed in neurons, blood vessels, subpial regions, and white matter tracts that form the basis of Scherer's secondary structures. In contrast, the SDF-1α receptor, CXCR4, was highly expressed in invading glioma cells organized around neurons and blood vessels, in subpial regions, and along white matter tracts. Neuronal and endothelial cells exposed to vascular endothelial growth factor up-regulated the expression of SDF-1α. CXCR4-positive tumor cells migrated toward a SDF-1α gradient in vitro, whereas inhibition of CXCR4 expression decreased their migration. Similarly, inhibition of CXCR4 decreased levels of SDF-1α-induced phosphorylation of FAK, AKT, and ERK1/2, suggesting CXCR4 involvement in glioma invasion signaling. These studies offer one plausible molecular basis and explanation of the formation of Scherer's structures in glioma patients.

To retrospectively determine whether relative cerebral blood volume (CBV) measurements can be used to predict clinical outcome in patients with high-grade gliomas (HGGs) and low-grade gliomas (LGGs) and specifically whether patients who have gliomas with a high initial relative CBV have more rapid progression than those who have gliomas with a low relative CBV.Approval for this retrospective HIPAA-compliant study was obtained from the Institutional Board of Research Associates, with waiver of informed consent. One hundred eighty-nine patients (122 male and 67 female patients; median age, 43 years; range, 4-80 years) were examined with dynamic susceptibility-weighted contrast material-enhanced perfusion magnetic resonance (MR) imaging and were followed up clinically with MR imaging (median follow-up, 334 days). Log-rank tests were used to evaluate the association between relative CBV and time to progression by using Kaplan-Meier curves. Binary logistic regression was used to determine whether age, sex, and relative CBV were associated with an adverse event (progressive disease or death).Values for the mean relative CBV for patients according to each clinical response were as follows: 1.41 +/- 0.13 (standard deviation) for complete response (n = 4), 2.36 +/- 1.78 for stable disease (n = 41), 4.84 +/- 3.32 for progressive disease (n = 130), and 3.82 +/- 1.93 for death (n = 14). Kaplan-Meier estimates of median time to progression in days indicated that patients with a relative CBV of less than 1.75 had a median time to progression of 3585 days, whereas patients with a relative CBV of more than 1.75 had a time to progression of 265 days. Age and relative CBV were also independent predictors for clinical outcome.Dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging can be used to predict median time to progression in patients with gliomas, independent of pathologic findings. Patients who have HGGs and LGGs with a high relative CBV (1.75) have a significantly more rapid time to progression than do patients who have gliomas with a low relative CBV.

Objectives We evaluated and compared tumor antigen precursor protein (TAPP) profiles in adult and pediatric brain tumors of 31 genes related to tumor associated antigens (TAA) for possible use in immunotherapy. Antigens were selected based on their potential to stimulate T cell responses against tumors of neuroectodermal origin. Methods Thirty-seven brain tumor specimens from 11 adult and 26 pediatric patients were analyzed by quantitative real-time PCR for the relative expression of 31 TAPP mRNAs. The age range of adults (4F:7M) was 27–77 years (median 51.5 ± 14.5 years) and for pediatrics (12F:14M) was 0.9–19 years (median 8.3 ± 5.5 years). Histological diagnoses consisted of 16 glioblastomas, 4 low grade astrocytomas, 10 juvenile pilocytic astrocytomas, and 7 ependymomas. Results The adult gliomas expressed 94% (29 of 31) of the TAPP mRNAs evaluated compared with pediatric brain tumors that expressed 55–74% of the TAPP mRNAs, dependent on tumor histological subtype. Four types of TAPP expression patterns were observed: (1) equal expression among adult and pediatric cases, (2) greater expression in adult than pediatric cases, (3) expression restricted to adult GBM and (4) a random distribution. The pediatric brain tumors lacked expression of some genes associated with engendering tumor survival, such as hTert and Survivin. Conclusions The potential TAA targets identified from the TAPP profiles of 31 genes associated with adult and pediatric brain tumors may help investigators select specific target antigens for developing dendritic cell- or peptide-based vaccines or T cell-based immunotherapeutic approaches against brain tumors.

OBJECTIVE: Diffusion tensor imaging (DTI) allows in vivo delineation of brainstem white matter tracts. The purpose of this study was to determine whether or not abnormalities of DTI metrics and fiber tractography correlate with neurological deficits and clinical status in patients with primary posterior fossa tumors. METHODS: A review of patients with primary posterior fossa tumors who underwent magnetic resonance imaging with DTI was performed. Patients were stratified by tumor type (well-circumscribed or infiltrating lesions). Fractional anisotropy (FA) color maps were used to localize the corticospinal tracts within the brainstem. FA, mean diffusivity, and eigenvalues were measured. Tractography was performed. Correlations between DTI metrics and clinical status and between DTI metrics and neurological examination findings were assessed within each patient group using Bonferroni correction for multiple comparisons. Comparisons of DTI metrics were also made between patient groups (infiltrating lesions versus well-circumscribed lesions). RESULTS: Thirty patients were studied (mean age, 14.1 yr; 16 male, 14 female). Eighteen patients had infiltrating lesions and 12 had well-circumscribed lesions. Twelve patients (four well-circumscribed and eight infiltrating) demonstrated motor weakness on physical examination (four right, three left, five bilateral). Patients with well-circumscribed lesions and weakness had higher mean diffusivity and lower FA in the contralateral corticospinal tract (P < 0.05). No such association was seen in patients with infiltrating tumors. In 102 total patient-years of follow-up (average follow-up period, 4.2 yr), 17 patients (six well-circumscribed and 11 infiltrating lesions) demonstrated complete response or stable disease and six patients (three well-circumscribed and three infiltrating lesions) demonstrated progressive disease or death. No differences were seen in terms of DTI metrics between patients with infiltrating lesions and those with well-circumscribed lesions. Patients with well-circumscribed tumors and a bad outcome had significantly lower transverse eigenvalue measures in the corticospinal tracts compared with those with a more favorable clinical status (P < 0.05). CONCLUSION: In patients with well-circumscribed primary posterior fossa masses, higher mean diffusivity and lower FA in the brainstem corticospinal tract are associated with contralateral motor deficits; lower transverse eigenvalue may be observed with an unfavorable clinical outcome.

Geldanamycin is a naturally occurring benzoquinone ansamycin product of Streptomyces geldanus that binds the protein chaperone heat shock protein 90. As geldanamycin binds to heat shock protein 90 interfering with its function and heat shock protein 90 is overexpressed in many cancers, heat shock protein 90 has become a target for cancer therapy. As the geldanamycin analogue 17-allylamino-17-demethoxygeldanamycin has a favorable toxicity profile, it is being tested extensively in clinical trials in patients with advanced cancer. In this study, GL261 glioma cells from C57BL/6 mice were used to investigate the anti-tumor effect of 17-allylamino-17-demethoxygeldanamycin both in vitro and in vivo. Heat shock protein 90 inhibitors possess potent anti-proliferative activity, usually at low nanomolar ranges, owing to their pharmacological characteristics of binding tightly to heat shock protein 90, coupled with a slow dissociation rate. We found that 17-allylamino-17-demethoxygeldanamycin at doses as low as 200 nmol/l showed anti-tumor activity within 24 h of treatment. Treatment with 17-allylamino-17-demethoxygeldanamycin arrested GL261 cells in the G2 phase of the cell cycle associated with the downregulation of cyclin B1. Low doses of 17-allylamino-17-demethoxygeldanamycin significantly inhibited migration of GL261 cells within 16 h of treatment, concomitant with the downregulation of phosphorylated focal adhesion kinase and matrix metalloproteinase 2 secretion. Using an orthotopic glioma model with well-established intracranial tumors, 3 weekly cycles of 17-allylamino-17-demethoxygeldanamycin significantly reduced tumor volumes of treated animals compared with untreated controls (P=0.002). Given these promising results, clinical testing of 17-allylamino-17-demethoxygeldanamycin or other novel heat shock protein 90 inhibitors being developed should be considered for glioma patients whose tumors remain refractory to most current treatment regimens.

Cell cycle progression requires precise expression and activation of several cyclins and cyclin-dependent kinases. Geldanamycin (GA) affects cell cycle progression in various kinds of cells. We analyzed GA-induced cell cycle regulation in glioblastoma cells. GA-induced G2 or M arrest in glioblastoma cells in a cell line-dependent manner. GA decreased the expression of Cdc2 and cyclin B1 in U87MG cells. And phosphorylated Cdc2 decreased along with Cdc2 in the GA-treated cells. This cell line showed G2 arrest after GA treatment. In contrast, GA failed to down-regulate these cell cycle regulators in U251MG cells. In U251MG cells, the cell cycle was arrested at M phase in addition to G2 by GA. Next, we analyzed the mechanism of the GA-induced regulation of Cdc2 and cyclin B1 in U87MG cells. Cdc2 and cyclin B1 were ubiquitinated by GA. MG132 abrogated the GA-induced decrease of Cdc2 and cyclin B1 indicating that these proteins were degraded by proteasomes. In conclusion, GA controls the stability of Cdc2 and cyclin B1 in glioblastomas cell species-dependently. Cdc2 and cyclin B1 might be responsible for the different responses of glioblastoma cell lines to GA.

We describe a lesion with the MR imaging characteristics of a glioblastoma mutiforme and demonstrate how perfusion MR imaging and proton MR spectroscopic imaging can be used to differentiate necrotizing cerebritis from what appeared to be a high-grade glioma. A 43 year old woman presented to her physician complaining of progressive visual disturbance and headache for several weeks. Conventional MR imaging demonstrated a parietal peripherally enhancing mass with central necrosis and moderate to severe surrounding T2 hyperintensity suggesting an infiltrating high-grade glioma. However, advanced imaging, including dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) and magnetic resonance spectroscopic imaging (MRSI), suggested a non-neoplastic lesion. The DSC MRI data demonstrated no hyperperfusion within the lesion and surrounding T2 signal abnormality and the MRSI data showed overall decrease in metabolites in this region, except for lactate. Because of the aggressive appearance to the lesion and the patients worsening symptoms, a biopsy was performed. The pathologic diagnosis was necrotizing cerebritis. After the commencement of steroid therapy, imaging findings and patient symptoms improved. This report will review the utility of advanced imaging for differentiating inflammatory from neoplastic appearing lesions on conventional imaging.

PURPOSE: To determine if increased perfusion using dynamic susceptibility contrast perfusion MRI (DSC MRI) in gliomas may be predictive of 1p19q deletions. Loss of heterozygosity of chromosomes 1p and 19q confers responsiveness to chemotherapy improving survival in gliomas. MATERIALS AND METHODS: We retrospectively reviewed 16 patients who had DSC MRI and molecular studies of their excised gliomas for 1p19q deletions. Allelic status was assessed by loss of heterozygosity using polymerase chain reaction (PCR). DNA was extracted from paraffin curls of brain tumor sections and nail clippings. Relative cerebral blood volume (rCBV) measurements were then statistically compared with the presence of 1p and 19q deletions. RESULTS: Patients with 1p19q deletions (N = 7) demonstrated rCBV values of 10.54 +/- 2.93. Patients without 1p deletions (N = 9) had rCBV values of 4.84 +/- 2.4 (P = 0.012). Logistic regression demonstrated that rCBV was able to predict the presence of a 1p deletion to significance levels of 0.038 and 0.044, adjusted and not adjusted for age and sex, respectively. The kappa coefficient for the agreement between predicted deletion status using rCBV and the truedeletion status was 0.746 (P = 0.0028). Deletions of 19q alone, or together with 1p deletions, were not associated with high rCBV. CONCLUSION: Histopathologic, molecular, and imaging evidence supports increased neovascularity in gliomas with 1p deletions in this preliminary study. We propose a diagnostic algorithm to obtain molecular studies in gliomas demonstrating high rCBV.

Mutations in isocitrate dehydrogenase 1 and 2 (mutIDH1/2) are common in gliomas, resulting in enzymes that produce D-2-hydroxyglutarate (D-2-HG). The effects of mutIDH1/2 on the microenvironment, including thrombosis, are not known. In discovery and validation cohorts of World Health Organization (WHO) grade II-IV gliomas from two institutions (total N = 317), microthrombi were present in 85-90% of wild-type gliomas but in only 2-6% of mutant gliomas (P < 0.0001), and their absence was an independent predictor of mutIDH1/2. Systemic hypercoagulation occurred in 25-30% of patients with wild-type IDH1/2 gliomas, but in 0% of patients with mutIDH1/2 gliomas (P < 0.0001). The prognostic strength of microthrombi was comparable to necrosis and microvascular proliferation, the current WHO criteria for a diagnosis of glioblastoma. In silico analysis of 428 gliomas from The Cancer Genome Atlas (TCGA) revealed that, in the coagulome, the mRNA with the strongest inverse relationship to mutIDH1/2 was F3, encoding tissue factor procoagulant (P = 1.06E-52). MutIDH1/2 gliomas in the TCGA also had significantly elevated F3 promoter methylation (P < 0.0001). In a separate tissue microarray containing 95 gliomas, mutIDH1/2 tumors showed dramatically reduced tissue factor protein expression (P < 0.0001). Additionally, D-2-HG inhibited human platelet aggregation by blocking intracellular calcium accumulation. In human in vitro and mouse in vivo models, mutIDH1 and D-2-HG lowered free serum calcium by up to 40% and markedly impaired coagulation (P < 0.0001). In sum, mutIDH1/2 enzymes have potent antithrombotic activity within gliomas and systemically. These findings have profound implications for the pathologic evaluation of gliomas, the effect of altered isocitrate metabolism on tumor microenvironment and calcium homeostasis, and the pre-and postoperative management of these patients.

INTRODUCTION: Pineoblastoma (PB) is one of the rarest and most aggressive brain tumors of childhood. PB is considered a "primitive neuroectodermal tumor" (PNET) based on histology, and commonly treated using treatment protocols developed for medulloblastoma. A subset of PBs may occur in the setting of germline mutations involving DICER1, but no next-generation sequencing studies have been published on PB to date, and the genetic drivers of sporadic PB remain unknown. METHODS: 21 tumor samples with a histological diagnosis of PB (including recurrent/metastatic samples) from 15 patients were included in this study. Matching germline DNA was available from 2 patients. We performed genome-wide methylation array profiling (Illumina Infinium 450k) on all samples, as well as whole-genome (for samples with matching germline DNA) or whole-exome sequence analysis. Fluorescence in situ hybridization (FISH) and digital droplet PCR (ddPCR) was performed to confirm select focal somatic gains. RESULTS: 14/18 samples from 9/13 patients analyzed by 450k profiling had a methylation signature similar to previously profiled PBs from a reference cohort. Samples from 4 patients were found to be more consistent with a diagnosis of embryonal tumor with multilayered rosettes (ETMR) - like tumor (non 19q amplified), papillary tumor of the pineal region, or pineal parenchymal tumor of intermediate differentiation, respectively. No mutations in DICER1 or RB1 were found. Homozygous deletions in DROSHA were found in tumors from 3 PB patients. We identified novel and recurrent somatic gains involving chromosomal region 1q21 that were confirmed by FISH and ddPCR in 4/5 PB patients. CONCLUSION: Our studies revealed multiple candidate drivers of oncogenesis in PB. We identified novel homozygous deletions in DROSHA, a nuclease involved in microRNA processing. We also identified novel, highly recurrent somatic focal gains involving chromosomal region 1q21, which has been linked to brain growth, autism and schizophrenia, but not previously associated with cancer.

BACKGROUND: Long considered to be inert organelles for lipid storage, lipid droplets (LDs) have recently attracted great interest as dynamic structures central to cellular lipid and energy metabolism. hypoxia-inducible gene (HIG2) and perilipin 2 (PLIN2, adipophilin) are LD-associated proteins known to be upregulated by hypoxia (Bensaad, 2014) and/or following von Hippel-Lindau (VHL) gene inactivation (Togashi, 2005; Yao, 2005). We sought to determine whether overexpression of HIG2 and PLIN2 in response to hypoxia or pseudohypoxia may be involved in these histopathologic features of glioma and hemangioblastoma. METHODS: Tumor specimens from 12 patients with glioma grade II-IV (age 3-59 y) and 23 patients with CNS hemangioblastoma (age 15-63 y) were analyzed by immunohistochemistry (IHC) to delineate their expression of HIG2 and PLIN2. To evaluate the role of hypoxia, glioblastoma (GBM) tissues (n = 2) were double-label immunostained for HIF-1α and PLIN2 (Zagzag, 2008). Additionally, cultures of tumor spheres isolated from GBM patients (n = 2) (Bayin, 2014) were exposed to hypoxic (1% O2) conditions for 24-72 h, and the cell proteins analyzed by Western blots. RESULTS: HIG2 and PLIN2 were consistently expressed on LDs in hypoxic glioma tumor cells, including pseudopalisading cells in GBMs, but not in adjacent hyperplastic vessels, inflammatory cells or normal brain tissue, independently of tumor grade or the presence of IDH1 (n = 3) and/or TP53 (n = 7) mutations. Likewise, LDs in stromal tumor cells in hemangioblastoma were intensely immunopositive for HIG2 and PLIN2. Double-label IHC showed tight co-expression of HIF-1α and PLIN2 in glioma tumor cells, consistent with the hypoxic regulation of PLIN2. Similarly, expression of HIF-1α and HIG2 proteins was upregulated in GBM tumor spheres under hypoxic conditions. CONCLUSIONS: Our results suggest that HIG2 and PLIN2 are involved in the hypoxic adaptation of lipid metabolism during tumorigenesis, and may serve as specific biomarkers of glioma tumor cells and stromal cells in CNS hemangioblastoma.

INTRODUCTION: Pineoblastoma (PB) is one of the rarest and most aggressive brain tumors of childhood. PB is considered a “primitive neuroectodermal tumor” (PNET) based on histology, and commonly treated using treatment protocols developed for medulloblastoma. A subset of PBs may occur in the setting of germline mutations involving DICER1, but no next-generation sequencing studies have been published on PB to date, and the genetic drivers of sporadic PB remain unknown. METHODS: 21 tumor samples with a histological diagnosis of PB (including recurrent/metastatic samples) from 15 patients were included in this study. Matching germline DNA was available from 2 patients. We performed genome-wide methylation array profiling (Illumina Infinium 450k) on all samples, as well as whole-genome (for samples with matching germline DNA) or whole-exome sequence analysis. Fluorescence in situ hybridization (FISH) and digital droplet PCR (ddPCR) was performed to confirm select focal somatic gains. RESULTS: 14/18 samples from 9/13 patients analyzed by 450k profiling had a methylation signature similar to previously profiled PBs from a reference cohort. Samples from 4 patients were found to be more consistent with a diagnosis of embryonal tumor with multilayered rosettes (ETMR) - like tumor (non 19q amplified), papillary tumor of the pineal region, or pineal parenchymal tumor of intermediate differentiation, respectively. No mutations in DICER1 or RB1 were found. Homozygous deletions in DROSHA were found in tumors from 3 PB patients. We identified novel and recurrent somatic gains involving chromosomal region 1q21 that were confirmed by FISH and ddPCR in 4/5 PB patients. CONCLUSION: Our studies revealed multiple candidate drivers of oncogenesis in PB. We identified novel homozygous deletions in DROSHA, a nuclease involved in microRNA processing. We also identified novel, highly recurrent somatic focal gains involving chromosomal region 1q21, which has been linked to brain growth, autism and schizophrenia, but not previously associated with cancer.

Medulloblastoma comprises four distinct molecular variants with distinct genetics, transcriptomes, and outcomes. Subgroup affiliation has been previously shown to remain stable at the time of recurrence, which likely reflects their distinct cells of origin. However, a therapeutically relevant question that remains unanswered is subgroup stability in the metastatic compartment. We assembled a cohort of 12-paired primary-metastatic tumors collected in the MAGIC consortium, and established their molecular subgroup affiliation by performing integrative gene expression and DNA methylation analysis. Frozen tissues were collected and profiled using Affymetrix gene expression arrays and Illumina methylation arrays. Class prediction and hierarchical clustering were performed using existing published datasets. Our molecular analysis, using consensus integrative genomic data, establishes the unequivocal maintenance of molecular subgroup affiliation in metastatic medulloblastoma. We further validated these findings by interrogating a non-overlapping cohort of 19 pairs of primary-metastatic tumors from the Burdenko Neurosurgical Institute using an orthogonal technique of immunohistochemical staining. This investigation represents the largest reported primary-metastatic paired cohort profiled to date and provides a unique opportunity to evaluate subgroup-specific molecular aberrations within the metastatic compartment. Our findings further support the hypothesis that medulloblastoma subgroups arise from distinct cells of origin, which are carried forward from ontogeny to oncology.

© 2015 Elsevier Inc. Ependymal tumors across age groups are currently classified and graded solely by histopathology. It is, however, commonly accepted that this classification scheme has limited clinical utility based on its lack of reproducibility in predicting patients' outcome. We aimed at establishing a uniform molecular classification using DNA methylation profiling. Nine molecular subgroups were identified in a large cohort of 500 tumors, 3 in each anatomical compartment of the CNS, spine, posterior fossa, supratentorial. Two supratentorial subgroups are characterized by prototypic fusion genes involving RELA and YAP1, respectively. Regarding clinical associations, the molecular classification proposed herein outperforms the current histopathological classification and thus might serve as a basis for the next World Health Organization classification of CNS tumors.

Much of the interest in angiogenesis and hypoxia has led to investigating diagnostic imaging methodologies and developing efficacious agents against angiogenesis in gliomas. In many ways, because of the cytostatic effects of these agents on tumor growth and tumor-associated endothelial cells, the effects of therapy are not immediately evident. Hence finding clinically applicable imaging tools and pathologic surrogate markers is an important step in translating glioma biology to therapeutics. There are a variety of strategies in the approach to experimental therapeutics that target the hypoxia-inducible factor pathway, the endogenous antiangiogenic and proangiogenic factors and their receptors, adhesion molecules, matrix proteases and cytokines, and the existing vasculature. We discuss the rationale for antiangiogenesis as a treatment strategy, the preclinical and clinical assessment of antiangiogenic interventions and finally focus on the various treatment strategies, including combining antiangiogenic drugs with radiation and chemotherapy.

Response of a solid tumor to radiation treatment depends, in part, on the intrinsic radiosensitivity of tumor cells, the proliferation rate of tumor cells between radiation treatments and the hypoxic state of the tumor cells. A successful radiosensitizing agent would target S-phase cells and hypoxia. Recently, we demonstrated the anti-tumor effects of flavopiridol in the GL261 murine glioma model might involve 1) recruitment of tumor cells to S-phase (Newcomb et al Cell Cycle 2004; 3:230-234) and 2) an anti-angiogenic effect on the tumor vasculature by downregulation of hypoxia-inducible factor -1alpha (HIF-1alpha) (Newcomb et al Neuro-Oncology 2005; 7:225-235). Given that flavopiridol has demonstrated radiosensitizing activity in several murine tumor models, we tested whether it would enhance the response of GL261 tumors to radiation. In the present study, we evaluated the intrinsic radiation sensitivity of the GL261 glioma model using the tumor control/cure dose of radiation assay (TCD(50)). We found that a single dose of 65 Gy (CI 57.1-73.1) was required to cure 50% of the tumors locally. Using the tumor growth delay assay, fractionated radiation (5 fractions of 5 Gy over 10 days) combined with flavopiridol (5 mg/kg) given three times weekly for 3 cycles produced a significant growth delay. Our results indicate that the GL261 murine glioma model mimics the radioresistance encountered in human gliomas, and thus should prove useful in identifying promising new investigational radiosensitizers for use in the treatment of glioma patients.

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory disease of the CNS initiated by autoreactive CD4+ T cells. EAE classically presents with a progressive ascending paralysis and is a model of multiple sclerosis that recapitulates some aspects of the disease. In this report we describe a mouse strain that spontaneously develops a severe, nonclassical form of EAE with 100% incidence. The distinct clinical phenotype is marked initially by a slight head tilt, progressing to a severe head tilt, spinning, or a rotatory motion. Classical EAE spontaneously occurs in myelin basic protein (MBP)-specific TCR transgenic RAG-1−/− mice (referred to as T/R−), whereas nonclassical EAE spontaneously occurs in T/R− IFN-γ−/− mice (T/R−γ−). Thus, the TCR recognizes the same Ag (MBP) and uses identical TCR in both cases. The cellular infiltrate in nonclassical EAE is predominantly found in the brainstem and cerebellum, with very little inflammation in the spinal cord, which is primarily affected in classical disease. Importantly, depending on the genetic makeup and priming conditions of the MBP-specific T cells, nonclassical disease can occur in the presence of an inflammatory infiltrate with eosinophilic, neutrophilic, or monocytic characteristics. Finally, we believe that nonclassical spontaneous EAE could be a useful model for the study of some characteristics of multiple sclerosis not observed in classical EAE, such as the inflammatory responses in the brainstem and cerebellum that can cause vertigo.

Advanced MRI techniques, such as MR spectroscopy, diffusion and perfusion MR imaging can give important in vivo physiological and metabolic information, complementing morphologic findings from conventional MRI in the clinical setting. Combining perfusion MRI and MR spectroscopy can help in patients with brain masses in who the pre-operative differential diagnosis is unclear. This review demonstrates the use of dynamic, susceptibility weighted, contrast-enhanced MR imaging (DSC MRI) and magnetic resonance spectroscopic imaging (MRSI) to distinguish surgical from non-surgical lesions in the brain. There is overlap in the MRI appearance of many enhancing and ring-enhancing lesions such as gliomas, metastases, inflammatory lesions, demyelinating lesions, subacute ischemia, abscess and some AIDS related lesions. We review examples of histopathologically confirmed high-grade glioma, a middle cerebral artery territory infarct, a tumefactive demyelinating lesion and a metastasis for which conventional MR imaging (MRI) was non-specific and potentially misleading and demonstrate how DSC MRI and MRSI features were used to increase the specificity of neurodiagnosis. At several institutions, many patients routinely undergo MRI as well as MRSI and DSC MRI. Cerebral blood flow (CBF), mean transit time (MTT), and relative cerebral blood volume (rCBV) measurements are obtained from regions of maximal perfusion as determined from perfusion color overlay maps. Metabolite levels and ratios are determined for Choline (Cho), N-Acetyl Aspartate (NAA), Lactate and Lipids (LL). Metabolite levels are obtained by measuring the peak heights of each metabolite and the ratios are obtained from these measurements for Cho/Cr, Cho/NAA and NAA/Cr. Neurosurgical intervention carries substantial morbidity, mortality, financial and potential emotional cost to the patient and family. Making a pre-operative diagnosis allows the neurosurgeon to be confident in the choice of treatment plan for the patient and allays considerable patient anxiety. The utility of combining clinical findings with multi-parametric information from perfusion and spectroscopic MR imaging in differentiating surgical lesions from those which do not require surgical intervention is discussed.

To determine whether diffusion-tensor magnetic resonance (MR) imaging metrics of peritumoral edema can be used to differentiate intra- from extraaxial lesions, metastatic lesions from gliomas, and high- from low-grade gliomas.In this study, diffusion-tensor MR imaging was performed preoperatively in 40 patients with intracranial neoplasms, including meningiomas, metastatic lesions, glioblastomas multiforme, and low-grade gliomas. Histograms of mean diffusivity (MD) and fractional anisotropy (FA) were used to analyze both the tumor and the associated T2 signal intensity abnormality. An additional metric, the tumor infiltration index (TII), was evaluated. The TII is a measure of the change in FA presumably caused by tumor cells infiltrating the peritumoral edema. Student t test and least-squares linear regression analyses were performed.Peritumoral MD and FA values indicated no statistically significant difference between intra- and extraaxial lesions or between high- and low-grade gliomas. Regarding intraaxial tumors, the measured mean peritumoral MD of metastatic lesions, 0.733 x 10(-3) mm(2)/sec +/- 0.061 (SD), was significantly higher than that of gliomas, 0.587 +/- 0.093 x 10(-3) mm(2)/sec (P.05). There was also a statistically significant difference between the TIIs of the edema surrounding meningiomas and metastases (mean, 0 +/- 35) and the TIIs of the edema surrounding gliomas (mean, 64 +/- 59) (P.05).Peritumoral diffusion-tensor MR imaging metrics enable the differentiation of solitary intraaxial metastatic brain tumors from gliomas. In addition, the TII enables one to distinguish presumed tumor-infiltrated edema from purely vasogenic edema.

The mechanism of action of many chemotherapeutic agents targets the cell cycle. Recently, we demonstrated cytotoxic and other anti-tumor effects of flavopiridol, the first synthetic cyclin dependent kinase (CDK) inhibitor to enter clinical trials, on the murine GL261 glioma cell line in vitro (Newcomb et al., Cell Cycle 2003; 2:243). Given that flavopiridol has demonstrated anti-tumor activity in several human xenograft models, we wanted to evaluate it for anti-glioma activity in vivo in our established subcutaneous and intracranial GL261 experimental tumor models. In particular, the intracranial animal model recapitulates many of the histopathological and biological features of human high-grade glioma including both necrosis with pseudopalisading and invasion of the brain adjacent to tumor. Here we tested the activity of flavopiridol against tumors formed by GL261 cells, first as subcutaneous implants, and then in the intracranial model. We demonstrate efficacy of flavopiridol as a single modality treatment in delaying tumor growth in both animal models. We hypothesize that flavopiridol treatment induced tumor growth delay by two possible mechanisms involving growth arrest combined with recruitment of tumor cells to S-phase. Based on our findings, flavopiridol should be considered as a treatment approach for patients with high-grade glioma.

OBJECTIVE To describe the pathological features of three very similar and unusual primary central nervous system tumors that are not readily recognized as conventional ependymomas but which, by ultrastructural examination, have an ependymomatous character. METHODS Three distinctive tumors were found in a review of our files for cases of ependymoma. In each case, hematoxylin and eosin-stained sections were reviewed, and immunostains for epithelial membrane antigen, cytokeratin, vimentin, and glial fibrillary acidic protein were performed on formalin-fixed, paraffin-embedded sections. Electron microscopy was performed in each case. RESULTS The tumors had a diffuse myxoid background, often containing tightly clustered cells that mimicked multinucleated giant cells, but lacking perivascular pseudorosettes or central lumen rosettes. Glial fibrillary acidic protein and vimentin immunostains did not reveal perivascular processes. Epithelial membrane antigen immunostains showed a dot-like cytoplasmic immunoreactivity in some cell clusters in two of the three cases. Cytokeratin was negative in all three cases. However, ultrastructurally, the cells of each tumor had extensive surface microvilli; the giant cell-like clusters had cells with extensive close appositions, some junctions, and, in two cases, lumina with microvilli. Two of the patients were adults (both with temporal lobe tumors), and one patient was 13 years old and had a cervical spinal cord intramedullary tumor. Each tumor was sharply circumscribed from adjacent central nervous system tissue but was not encapsulated. One of the cases in an adult was mitotically highly active; this tumor recurred locally 4 years after initial gross total excision. CONCLUSION These tumors are unusual variants of ependymoma. This pattern of ependymoma is sufficiently distinctive to be recognized in hematoxylin and eosin stains once the architecture of the epithelioid clusters is appreciated.

Mycosis fungoides is a malignant, cutaneous lymphoma of T-helper (TH or CD4+) cells. At presentation, the disease is usually limited to the skin, with lesions that resemble eczema or psoriasis. Neurologic involvement is uncommon. This case demonstrates the conventional MRI and dynamic contrast enhanced perfusion MRI findings in intracerebral mycosis fungoides. T1-weighted spin echo imaging demonstrated a lesion with slightly decreased signal within the body of the corpus callosum. The lesion was isointense with grey matter on axial T2-weighted imaging. Following administration of contrast, there was patchy heterogeneous enhancement. Multiple relative cerebral blood volume (rCBV) measurements were made and the minimum rCBV was 0.30 with the maximum rCBV being 1.61. The mean rCBV was 0.81 +/- 0.49 (average of 10 measurements and standard deviation).

Despite clear indications of their importance in lower organisms, the contributions of protein tyrosine phosphatases (PTPs) to development or function of the mammalian nervous system have been poorly explored. In vitro studies have indicated that receptor protein tyrosine phosphatase alpha (RPTPalpha) regulates SRC family kinases, potassium channels and NMDA receptors. Here, we report that absence of RPTPalpha compromises correct positioning of pyramidal neurons during development of mouse hippocampus. Thus, RPTPalpha is a novel member of the functional class of genes that control radial neuronal migration. The migratory abnormality likely results from a radial glial dysfunction rather than from a neuron-autonomous defect. In spite of this aberrant development, basic synaptic transmission from the Schaffer collateral pathway to CA1 pyramidal neurons remains intact in Ptpra(-/-) mice. However, these synapses are unable to undergo long-term potentiation. Mice lacking RPTPalpha also underperform in the radial-arm water-maze test. These studies identify RPTPalpha as a key mediator of neuronal migration and synaptic plasticity.

Focal adhesion kinase (FAK) and hypoxia-inducible factor (HIF-1alpha) are both up-regulated in glioblastoma multiforme (GBMs), particularly in invasive zones. Because FAK may play an important role in the invasion of glioma cells into the surrounding brain, we sought an agent that causes down-regulation of FAK phosphorylation as a potential inhibitor of brain tumor invasion and growth. Geldanamycin (GA), a benzoquinone ansamycin antibiotic, binds to heat shock protein 90 (Hsp90) and interferes with its function. GA inhibits the proliferation of various non-glial cells and has anti-tumor activity. Moreover, GA blocks HIF-regulated transcription of VEGF and inhibits the VEGF-induced phosphorylation of FAK and migration of endothelial cells. Here, we tested the effect of GA on glioma cell migration in vitro and its potential to down-regulate HIF-1alpha induction. Our results demonstrate that GA (i) decreases U87MG, LN229, and U251MG glioma cell migration; (ii) reduces cell migration independent of p53 and PTEN status; (iii) prevents migration at non-toxic concentrations; (iv) reduces phosphorylation of FAK; and (v) inhibits cobalt chloride (CoCl(2))-mediated induction of HIF-1alpha in glioma cells. To the best of our knowledge, this is the first report showing that GA can inhibit phosphorylation of FAK concomitant with a decrease in cellular migration. One of the most clinically relevant aspects of this study is that GA interferes with the induction of HIF-1alpha that has been linked with glioma cell migration and angiogenesis. Given the fact that GA is a small lipophilic molecule capable of penetrating the blood brain barrier together with the data presented here provide a strong rationale for its use or its analogues in the treatment of highly invasive GBMs.

We recently identified a mutation in the I-kappa B kinase associated protein (IKBKAP) gene as the major cause of familial dysautonomia (FD), a recessive sensory and autonomic neuropathy. This alteration, located at base pair 6 of the intron 20 donor splice site, is present on99.5% of FD chromosomes and results in tissue-specific skipping of exon 20. A second FD mutation, a missense change in exon 19 (R696P), was seen in only four patients heterozygous for the major mutation. Here, we have further characterized the consequences of the major mutation by examining the ratio of wild-type to mutant (WT:MU) IKBKAP transcript in EBV-transformed lymphoblast lines, primary fibroblasts, freshly collected blood samples, and postmortem tissues from patients with FD. We consistently found that WT IKBKAP transcripts were present, albeit to varying extents, in all cell lines, blood, and postmortem FD tissues. Further, a corresponding decrease in the level of WT protein is seen in FD cell lines and tissues. The WT:MU ratio in cultured lymphoblasts varied with growth phase but not with serum concentration or inclusion of antibiotics. Using both densitometry and real-time quantitative polymerase chain reaction, we found that relative WT:MU IKBKAP RNA levels were highest in cultured patient lymphoblasts and lowest in postmortem central and peripheral nervous tissues. These observations suggest that the relative inefficiency of WT IKBKAP mRNA production from the mutant alleles in the nervous system underlies the selective degeneration of sensory and autonomic neurons in FD.Therefore, exploration of methods to increase the WT:MU IKBKAP transcript ratio in the nervous system offers a promising approach for developing an effective therapy for patients with FD.

E steemed neuroscientist and former Professor of Neuropathology at New York University Medical Center, Irwin Feigin, MD, was born on May 13, 1915, in Manhattan, and died peacefully on January 22,2015, in Jamaica, Queens, New York. During World War II, Dr. Feigin attended Columbia College at Columbia University (from where he graduated at the top of his class), and attended the New York University School of Medicine. Dr. Feigin then served for the United States Army in the Medical corps, landing in France the day after D-Day. While working for the military, he was engaged in research on the evidence of German biological warfare. Dr. Feigin's experience on the beaches of Normandy engendered a life-long abhorrence of aggression. Returning to the US, Dr. Feigin began his research career in neuropathology at NY Presbyterian Medical Center, where he worked with the eminent pathologist Dr. Abner Wolf (who would later become his brother-in-law). …

Cap43 is a protein whose RNA is induced under conditions of severe hypoxia or prolonged elevations of intracellular calcium. Additionally, Ni and Co also induce Cap43 because they produce a state of hypoxia in cells. Cap43 protein is expressed at low levels in normal tissues; however, in a variety of cancers, including lung, brain, melanoma, liver, prostate, breast, and renal cancers, Cap43 protein is overexpressed in cancer cells. The low level of expression of Cap43 in some normal tissues compared with their cancerous counterparts, combined with the high stability of Cap43 protein and mRNA, makes the Cap43 gene a new, important cancer marker. We hypothesize that the mechanism of Cap43 overexpression in cancer cells involves a state of hypoxia characteristic of cancer cells where the Cap43 protein becomes a signature for this hypoxic state. United States Department of Health & Human Services National Institutes of Health (NIH) - USA NIH National Institute of Environmental Health Sciences (NIEHS) [ (P30ES000260 P42ES010344 -- ES 10344 ES 05512 ES 00260 ) ]

INI1/hSNF5 is a component of the ATP-dependent chromatin remodeling hSWI/SNF complex and a tumor suppressor gene of aggressive pediatric atypical teratoid and malignant rhabdoid tumors (AT/RT). To understand the molecular mechanisms underlying its tumor suppressor function, we studied the effect of reintroduction of INI1/hSNF5 into AT/RT-derived cell lines such as MON that carry biallelic deletions of the INI1/hSNF5 locus. We demonstrate that expression of INI1/hSNF5 causes G(0)-G(1) arrest and flat cell formation in these cells. In addition, INI1/hSNF5 repressed transcription of cyclin D1 gene in MON, in a histone deacetylase (HDAC)-dependent manner. Chromatin immunoprecipitation studies revealed that INI1/hSNF5 was directly recruited to the cyclin D1 promoter and that its binding correlated with recruitment of HDAC1 and deacetylation of histones at the promoter. Analysis of INI1/hSNF5 truncations indicated that cyclin D1 repression and flat cell formation are tightly correlated. Coexpression of cyclin D1 from a heterologous promoter in MON was sufficient to eliminate the INI1-mediated flat cell formation and cell cycle arrest. Furthermore, cyclin D1 was overexpressed in AT/RT tumors. Our data suggest that one of the mechanisms by which INI1/hSNF5 exerts its tumor suppressor function is by mediating the cell cycle arrest due to the direct recruitment of HDAC activity to the cyclin D1 promoter thereby causing its repression and G(0)-G(1) arrest. Repression of cyclin D1 gene expression may serve as a useful strategy to treat AT/RT.

Dynamic contrast agent-enhanced perfusion magnetic resonance (MR) imaging provides physiologic information that complements the anatomic information available with conventional MR imaging. Analysis of dynamic data from perfusion MR imaging, based on tracer kinetic theory, yields quantitative estimates of cerebral blood volume that reflect the underlying microvasculature and angiogenesis. Perfusion MR imaging is a fast and robust imaging technique that is increasingly used as a research tool to help evaluate and understand intracranial disease processes and as a clinical tool to help diagnose, manage, and understand intracranial mass lesions. With the increasing number of applications of perfusion MR imaging, it is important to understand the principles underlying the technique. In this review, the essential underlying physics and methods of dynamic contrast-enhanced susceptibility-weighted echo-planar perfusion MR imaging are described. The clinical applications of cerebral blood volume maps obtained with perfusion MR imaging in the differential diagnosis of intracranial mass lesions, as well as the pitfalls and limitations of the technique, are discussed. Emphasis is on the clinical role of perfusion MR imaging in providing insight into the underlying pathophysiology of cerebral microcirculation.