Glioma progression is shaped by genetic evolution and microenvironment interactions.

The factors driving therapy resistance in diffuse glioma remain poorly understood. To identify treatment-associated cellular and genetic changes, we analyzed RNA and/or DNA sequencing data from the temporally separated tumor pairs of 304 adult patients with isocitrate dehydrogenase (IDH)-wild-type and IDH-mutant glioma. Tumors recurred in distinct manners that were dependent on IDH mutation status and attributable to changes in histological feature composition, somatic alterations, and microenvironment interactions. Hypermutation and acquired CDKN2A deletions were associated with an increase in proliferating neoplastic cells at recurrence in both glioma subtypes, reflecting active tumor growth. IDH-wild-type tumors were more invasive at recurrence, and their neoplastic cells exhibited increased expression of neuronal signaling programs that reflected a possible role for neuronal interactions in promoting glioma progression. Mesenchymal transition was associated with the presence of a myeloid cell state defined by specific ligand-receptor interactions with neoplastic cells. Collectively, these recurrence-associated phenotypes represent potential targets to alter disease progression.

PD-1 Inhibitory Receptor Downregulates Asparaginyl Endopeptidase and Maintains Foxp3 Transcription Factor Stability in Induced Regulatory T Cells.

CD4+ T cell differentiation into multiple T helper (Th) cell lineages is critical for optimal adaptive immune responses. This report identifies an intrinsic mechanism by which programmed death-1 receptor (PD-1) signaling imparted regulatory phenotype to Foxp3+ Th1 cells (denoted as Tbet+iTregPDL1 cells) and inducible regulatory T (iTreg) cells. Tbet+iTregPDL1 cells prevented inflammation in murine models of experimental colitis and experimental graft versus host disease (GvHD). Programmed death ligand-1 (PDL-1) binding to PD-1 imparted regulatory function to Tbet+iTregPDL1 cells and iTreg cells by specifically downregulating endo-lysosomal protease asparaginyl endopeptidase (AEP). AEP regulated Foxp3 stability and blocking AEP imparted regulatory function in Tbet+iTreg cells. Also, Aep-/- iTreg cells significantly inhibited GvHD and maintained Foxp3 expression. PD-1-mediated Foxp3 maintenance in Tbet+ Th1 cells occurred both in tumor infiltrating lymphocytes (TILs) and during chronic viral infection. Collectively, this report has identified an intrinsic function for PD-1 in maintaining Foxp3 through proteolytic pathway.

Cystatin F Ensures Eosinophil Survival by Regulating Granule Biogenesis.

Eosinophils are now recognized as multifunctional leukocytes that provide critical homeostatic signals to maintain other immune cells and aid tissue repair. Paradoxically, eosinophils also express an armory of granule-localized toxins and hydrolases believed to contribute to pathology in inflammatory disease. How eosinophils deliver their supporting functions while avoiding self-inflicted injury is poorly understood. We have demonstrated that cystatin F (CF) is a critical survival factor for eosinophils. Eosinophils from CF null mice had reduced lifespan, reduced granularity, and disturbed granule morphology. In vitro, cysteine protease inhibitors restored granularity, demonstrating that control of cysteine protease activity by CF is critical for normal eosinophil development. CF null mice showed reduced pulmonary pathology in a model of allergic lung inflammation but also reduced ability to combat infection by the nematode Brugia malayi. These data identify CF as a "cytoprotectant" that promotes eosinophil survival and function by ensuring granule integrity. VIDEO ABSTRACT.

A career in neurosurgery: perceptions and the impact of a national SBNS/NANSIG neurosurgery careers day.

OBJECTIVE: Entrance to neurosurgical training is highly competitive. Without proper advice, information and opportunities, talented individuals may be dissuaded from applying. The Neurology and Neurosurgery Interest Group (NANSIG) organises a Careers Day in Neurosurgery every year. Our objective was to assess the overall utility of a neurosurgery careers day and the perceived factors that attract and detract from the specialty, from attendees of the ninth annual neurosurgery careers day. METHODS: Eighteen-item pre-conference and 19-item post-conference questionnaires were disseminated electronically to conference attendees. Questions aimed to capture: (i) baseline demographics; (ii) previous experience and exposure in neurosurgery; (iii) interest in neurosurgery; (iv) understanding training and a career in neurosurgery; (v) perceived factors of attraction and dissuasion of neurosurgery; and (vi) perceived value, quality and educational purpose of the conference. RESULTS: In total, 77 delegates attended the careers day. Most did not have a formal neurosurgical rotation during medical school (24.7%, n = 19), but almost half had gained neurosurgical experience and presented research work. The careers day increased knowledge of the neurosurgical application process (median Likert score 3/5 to 4/5, p < 0.01), duration of training (72.7-88.3%), and desire to pursue a career in neurosurgery (75.3-81.8%). The most commonly reported factors attracting delegates to neurosurgery were interest in neuroanatomy (80.5%, n = 62), practical skills (64.9%, n = 50), and impact on patients (62.3%, n = 48). The most common dissuasive factors were competition to entry (64.9%, n = 50), long working hours (40.3%, n = 31), and other career interests (35.1%, n = 27). Almost all would recommend the event to a colleague (94.9%, n = 73). CONCLUSIONS: Formal undergraduate exposure to neurosurgery is limited. Neurosurgery careers days increase awareness and understanding of the application process and improve interest in a selected cohort. The factors attracting applicants to neurosurgery remain practical links to neuroanatomy, opportunities in neurosurgery for innovation and research, and direct impact on patients.

Tumour treating fields in glioblastoma: is the treatment tolerable, effective, and practical in UK patients?

BACKGROUND: Tumour Treating Fields (TTF) in combination with standard therapy, prolongs survival in patients with glioblastoma (GBM). The aim of the current study was to assess the feasibility of integrating TTF into a standard UK neuro-oncology service with a focus on patient tolerability, compliance, and treatment delivery. METHODS: A prospective study was performed of UK patients with IDH 1 Wild Type, MGMT Unmethylated GBM treated with TTF, in conjunction with conventional therapy. Patient compliance data, device-specific tolerability questions, and an evaluation of disease progression and survival were collected. Monthly quality of life (QoL) questionnaires (EORTC QLQ-C30 with BN-20) examined the trend of global health, psychosocial function, and symptom progression. RESULTS: Nine patients were enrolled with a median age of 47 (seven males; two females). Overall, compliance with TTF was 89% (range 16-97%). Only one patient failed to comply with treatment. Patients tolerated the device with minimal side effects. Eight patients described mild to moderate skin irritation, whilst all patients were keen to recommend the device to other patients (100%). Most patients found the weight and size of the device to be its biggest drawback (72%). Progression-free survival was 5.5 months and median overall survival was 14.9 months. CONCLUSIONS: TTF was well-tolerated amongst a small cohort of UK patients, who were able to comply with treatment without any significant complication. QoL questionnaires showed no sustained deterioration in global health, physical and emotional function until the final months of life when the disease burden was greatest.

Intraoperative imaging technology to maximise extent of resection for glioma: a network meta-analysis.

BACKGROUND: Multiple studies have identified the prognostic relevance of extent of resection in the management of glioma. Different intraoperative technologies have emerged in recent years with unknown comparative efficacy in optimising extent of resection. One previous Cochrane Review provided low- to very low-certainty evidence in single trial analyses and synthesis of results was not possible. The role of intraoperative technology in maximising extent of resection remains uncertain. Due to the multiple complementary technologies available, this research question is amenable to a network meta-analysis methodological approach. OBJECTIVES: To establish the comparative effectiveness and risk profile of specific intraoperative imaging technologies using a network meta-analysis and to identify cost analyses and economic evaluations as part of a brief economic commentary. SEARCH METHODS: We searched CENTRAL (2020, Issue 5), MEDLINE via Ovid to May week 2 2020, and Embase via Ovid to 2020 week 20. We performed backward searching of all identified studies. We handsearched two journals, Neuro-oncology and the Journal of Neuro-oncology from 1990 to 2019 including all conference abstracts. Finally, we contacted recognised experts in neuro-oncology to identify any additional eligible studies and acquire information on ongoing randomised controlled trials (RCTs). SELECTION CRITERIA: RCTs evaluating people of all ages with presumed new or recurrent glial tumours (of any location or histology) from clinical examination and imaging (computed tomography (CT) or magnetic resonance imaging (MRI), or both). Additional imaging modalities (e.g. positron emission tomography, magnetic resonance spectroscopy) were not mandatory. Interventions included fluorescence-guided surgery, intraoperative ultrasound, neuronavigation (with or without additional image processing, e.g. tractography), and intraoperative MRI. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the search results for relevance, undertook critical appraisal according to known guidelines, and extracted data using a prespecified pro forma. MAIN RESULTS: We identified four RCTs, using different intraoperative imaging technologies: intraoperative magnetic resonance imaging (iMRI) (2 trials, with 58 and 14 participants); fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) (1 trial, 322 participants); and neuronavigation (1 trial, 45 participants). We identified one ongoing trial assessing iMRI with a planned sample size of 304 participants for which results are expected to be published around winter 2020. We identified no published trials for intraoperative ultrasound. Network meta-analyses or traditional meta-analyses were not appropriate due to absence of homogeneous trials across imaging technologies. Of the included trials, there was notable heterogeneity in tumour location and imaging technologies utilised in control arms. There were significant concerns regarding risk of bias in all the included studies. One trial of iMRI found increased extent of resection (risk ratio (RR) for incomplete resection was 0.13, 95% confidence interval (CI) 0.02 to 0.96; 49 participants; very low-certainty evidence) and one trial of 5-ALA (RR for incomplete resection was 0.55, 95% CI 0.42 to 0.71; 270 participants; low-certainty evidence). The other trial assessing iMRI was stopped early after an unplanned interim analysis including 14 participants; therefore, the trial provided very low-quality evidence. The trial of neuronavigation provided insufficient data to evaluate the effects on extent of resection. Reporting of adverse events was incomplete and suggestive of significant reporting bias (very low-certainty evidence). Overall, the proportion of reported events was low in most trials and, therefore, issues with power to detect differences in outcomes that may or may not have been present. Survival outcomes were not adequately reported, although one trial reported no evidence of improvement in overall survival with 5-ALA (hazard ratio (HR) 0.82, 95% CI 0.62 to 1.07; 270 participants; low-certainty evidence). Data for quality of life were only available for one study and there was significant attrition bias (very low-certainty evidence). AUTHORS' CONCLUSIONS: Intraoperative imaging technologies, specifically 5-ALA and iMRI, may be of benefit in maximising extent of resection in participants with high-grade glioma. However, this is based on low- to very low-certainty evidence. Therefore, the short- and long-term neurological effects are uncertain. Effects of image-guided surgery on overall survival, progression-free survival, and quality of life are unclear. Network and traditional meta-analyses were not possible due to the identified high risk of bias, heterogeneity, and small trials included in this review. A brief economic commentary found limited economic evidence for the equivocal use of iMRI compared with conventional surgery. In terms of costs, one non-systematic review of economic studies suggested that, compared with standard surgery, use of image-guided surgery has an uncertain effect on costs and that 5-ALA was more costly. Further research, including completion of ongoing trials of ultrasound-guided surgery, is needed.

ANTECEDENTES: En múltiples estudios se ha identificado la importancia pronóstica del alcance de la resección en el tratamiento del glioma. En los últimos años han surgido diferentes tecnologías intraoperatorias con una eficacia comparativa desconocida para optimizar el alcance de la resección. Una revisión Cochrane anterior proporcionó evidencia de certeza baja a muy baja en los análisis de un solo ensayo y no fue posible la síntesis de los resultados. La función de la tecnología intraoperatoria para maximizar el alcance de la resección aún no está clara. Debido a las múltiples tecnologías complementarias disponibles, esta pregunta de investigación se presta a un enfoque metodológico de metanálisis en red. OBJETIVOS: Establecer el perfil comparativo de efectividad y riesgo de determinadas tecnologías de imagenología intraoperatorias mediante un metanálisis en red e identificar análisis de costos y evaluaciones económicas como parte de un breve comentario económico. MÉTODOS DE BÚSQUEDA: Se hicieron búsquedas en CENTRAL (2020, número 5), MEDLINE vía Ovid hasta la semana 2 de mayo de 2020, y Embase vía Ovid hasta la semana 20 de 2020. Se realizó una búsqueda retrospectiva de todos los estudios identificados. Se hicieron búsquedas manuales en dos revistas, Neuro­oncology y Journal of Neuro­oncology, desde 1990 hasta 2019, y se incluyeron todos los resúmenes de congresos. Finalmente, se estableció contacto con expertos reconocidos en neurooncología para identificar cualquier estudio elegible adicional y obtener información sobre los ensayos controlados aleatorizados (ECA) en curso. CRITERIOS DE SELECCIÓN: ECA que evaluaron a personas de todas las edades con presuntos tumores gliales nuevos o recidivantes (de cualquier ubicación o histología) a partir del examen clínico y la imagenología (tomografía computarizada [TC] o imagenología de resonancia magnética [IRM], o ambas). Las modalidades adicionales de imagenología (p.ej., tomografía de emisión de positrones, espectroscopia de resonancia magnética) no fueron obligatorias. Las intervenciones incluyeron cirugía guiada por fluorescencia, ecografía intraoperatoria, neuronavegación (con o sin procesamiento adicional de las imágenes, p.ej., tractografía) e IRM intraoperatoria. OBTENCIÓN Y ANÁLISIS DE LOS DATOS: Dos autores de la revisión, de forma independiente, evaluaron los resultados de la búsqueda en cuanto a su relevancia, realizaron la evaluación crítica según las guías conocidas y extrajeron los datos mediante un formulario predeterminado. RESULTADOS PRINCIPALES: Se identificaron cuatro ECA, que utilizaron diferentes tecnologías de imagenología intraoperatorias: la resonancia magnética (IRM) intraoperatoria (dos ensayos, con 58 y 14 participantes); la cirugía guiada por fluorescencia con ácido 5­aminolevulínico (5­ALA) (un ensayo, 322 participantes); y la neuronavegación (un ensayo, 45 participantes). Se identificó un ensayo en curso que evaluó la IRM con un tamaño de la muestra planificado de 304 participantes, del que se espera la publicación de los resultados alrededor del invierno de 2020. No se han identificado ensayos publicados sobre la ecografía intraoperatoria. Los metanálisis en red o los metanálisis tradicionales no fueron apropiados debido a la falta de ensayos homogéneos en tecnologías de imagenología. De los ensayos incluidos, hubo una notable heterogeneidad en la localización de los tumores y en las tecnologías de imagenología utilizadas en los brazos control. Hubo inquietudes significativas con respecto al riesgo de sesgo en todos los estudios incluidos. Un ensayo de IRM encontró un aumento en la extensión de la resección (razón de riesgos [RR] para la resección incompleta 0,13; intervalo de confianza [IC] del 95%: 0,02 a 0,96; 49 participantes; evidencia de certeza muy baja) y un ensayo de 5­ALA (RR para la resección incompleta 0,55; IC del 95%: 0,42 a 0,71; 270 participantes; evidencia de certeza baja). El otro ensayo que evaluó la IRM se interrumpió de forma temprana después de un análisis intermedio no planificado que incluyó 14 participantes; por lo tanto, el ensayo proporciona evidencia de calidad muy baja. El ensayo de neuronavegación no proporcionó datos suficientes para evaluar los efectos sobre el grado de resección. El informe de los eventos adversos fue incompleto e indicó la presencia de sesgo de informe significativo (evidencia de certeza muy baja). En general, la proporción de eventos informados fue baja en la mayoría de los ensayos y, por lo tanto, pueden haber estado presentes o no problemas relacionados con el poder estadístico suficiente para detectar diferencias en los desenlaces. No se informó adecuadamente sobre los desenlaces de supervivencia, aunque un ensayo no informó evidencia de mejora en la supervivencia general con 5­ALA (cociente de riesgos instantáneos [CRI] 0,82; IC del 95%: 0,62 a 1,07; 270 participantes; evidencia de certeza baja). Solo hubo datos disponibles sobre la calidad de vida de un estudio, con un sesgo de desgaste significativo (evidencia de certeza muy baja). CONCLUSIONES DE LOS AUTORES: Las tecnologías de imagenología intraoperatoria, específicamente la IRM y el 5­ALA, pueden ser beneficiosas para maximizar el grado de resección en los participantes con glioma de grado alto. Sin embargo, lo anterior se basa en evidencia de certeza baja a muy baja. Por lo tanto, los efectos neurológicos a corto y a largo plazo no están claros. No están claros los efectos de la cirugía guiada por imágenes sobre la supervivencia general, la supervivencia sin progresión ni la calidad de vida. No fue posible realizar metanálisis en red ni tradicionales debido al alto riesgo de sesgo identificado, a la heterogeneidad y a los ensayos pequeños incluidos en esta revisión. Un comentario económico breve encontró evidencia económica limitada sobre el uso equívoco de la IRM en comparación con la cirugía convencional. En cuanto a los costos, una revisión no sistemática de estudios económicos indicó que, en comparación con la cirugía estándar, el uso de la cirugía guiada por imágenes no tiene un efecto claro sobre los costos y que el ácido 5­aminolevulínico fue más costoso. Se necesitan estudios de investigación adicionales, incluida la finalización de los ensayos en curso sobre la cirugía guiada por ecografía.

Widespread resetting of DNA methylation in glioblastoma-initiating cells suppresses malignant cellular behavior in a lineage-dependent manner.

Epigenetic changes are frequently observed in cancer. However, their role in establishing or sustaining the malignant state has been difficult to determine due to the lack of experimental tools that enable resetting of epigenetic abnormalities. To address this, we applied induced pluripotent stem cell (iPSC) reprogramming techniques to invoke widespread epigenetic resetting of glioblastoma (GBM)-derived neural stem (GNS) cells. GBM iPSCs (GiPSCs) were subsequently redifferentiated to the neural lineage to assess the impact of cancer-specific epigenetic abnormalities on tumorigenicity. GiPSCs and their differentiating derivatives display widespread resetting of common GBM-associated changes, such as DNA hypermethylation of promoter regions of the cell motility regulator TES (testis-derived transcript), the tumor suppressor cyclin-dependent kinase inhibitor 1C (CDKN1C; p57KIP2), and many polycomb-repressive complex 2 (PRC2) target genes (e.g., SFRP2). Surprisingly, despite such global epigenetic reconfiguration, GiPSC-derived neural progenitors remained highly malignant upon xenotransplantation. Only when GiPSCs were directed to nonneural cell types did we observe sustained expression of reactivated tumor suppressors and reduced infiltrative behavior. These data suggest that imposing an epigenome associated with an alternative developmental lineage can suppress malignant behavior. However, in the context of the neural lineage, widespread resetting of GBM-associated epigenetic abnormalities is not sufficient to override the cancer genome.

Advances in Research of Adult Gliomas.

Diffuse gliomas are the most frequent brain tumours, representing 75% of all primary malignant brain tumours in adults. Because of their locally aggressive behaviour and the fact that they cannot be cured by current therapies, they represent one of the most devastating cancers. The present review summarises recent advances in our understanding of glioma development and progression by use of various in vitro and in vivo models, as well as more complex techniques including cultures of 3D organoids and organotypic slices. We discuss the progress that has been made in understanding glioma heterogeneity, alteration in gene expression and DNA methylation, as well as advances in various in silico models. Lastly current treatment options and future clinical trials, which aim to improve early diagnosis and disease monitoring, are also discussed.

Detection of glioblastoma intratumor heterogeneity in radiosensitivity using patient-derived neurosphere cultures.

PURPOSE: Glioblastoma (GBM) is characterized by extensive clonal diversity suggesting the presence of tumor cells with varying degrees of treatment sensitivity. Radiotherapy is an integral part of glioblastoma treatment. Whether GBMs are comprised of spatially distinct cellular populations with uniform or varying degrees of radiosensitivity has not been established. METHODS: Spatially distinct regions of three GBMs (J3, J7 and J14) were resected and unique cell lines were derived from each region. DNA from cell lines, corresponding tumor fragments, and patient blood was extracted for whole exome sequencing. Variants, clonal composition, and functional implications were compared and analyzed with superFreq and IPA. Limiting dilution assays were performed on cell lines to measure intrinsic radiosensitivity. RESULTS: Based on WES, cell lines generated from different regions of the same tumor were more closely correlated with their tumor of origin than the other GBMs. Variant and clonal composition comparisons showed that cell lines from distinct tumors displayed increasing levels of ITH with J3 and J14 having the lowest and highest, respectively. The radiosensitivities of the cell lines generated from the J3 tumor were similar as were those generated from the J7 tumor. However, the radiosensitivities of the 2 cell lines generated from the J14 tumor (J14T3 and J14T6) were significantly different with J14T6 being more sensitive than J14T3. CONCLUSION: Data suggest a tumor dependent ITH in radiosensitivity. The existence of ITH in radiosensitivity may impact not only the initial therapeutic response but also the effectiveness of retreatment protocols.

Outcome of cell suspension allografts in a patient with Huntington's disease.

For patients with incurable neurodegenerative disorders such as Huntington's (HD) and Parkinson's disease, cell transplantation has been explored as a potential treatment option. Here, we present the first clinicopathological study of a patient with HD in receipt of cell-suspension striatal allografts who took part in the NEST-UK multicenter clinical transplantation trial. Using various immunohistochemical techniques, we found a discrepancy in the survival of grafted projection neurons with respect to grafted interneurons as well as major ongoing inflammatory and immune responses to the grafted tissue with evidence of mutant huntingtin aggregates within the transplant area. Our results indicate that grafts can survive more than a decade post-transplantation, but show compromised survival with inflammation and mutant protein being observed within the transplant site. Ann Neurol 2018;84:950-956.

Non-invasive assessment of glioma microstructure using VERDICT MRI: correlation with histology.

PURPOSE: This prospective study evaluated the use of vascular, extracellular and restricted diffusion for cytometry in tumours (VERDICT) MRI to investigate the tissue microstructure in glioma. VERDICT-derived parameters were correlated with both histological features and tumour subtype and were also used to explore the peritumoural region. METHODS: Fourteen consecutive treatment-naïve patients (43.5 years ± 15.1 years, six males, eight females) with suspected glioma underwent diffusion-weighted imaging including VERDICT modelling. Tumour cell radius and intracellular and combined extracellular/vascular volumes were estimated using a framework based on linearisation and convex optimisation. An experienced neuroradiologist outlined the peritumoural oedema, enhancing tumour and necrosis on T2-weighted imaging and contrast-enhanced T1-weighted imaging. The same regions of interest were applied to the co-registered VERDICT maps to calculate the microstructure parameters. Pathology sections were analysed with semi-automated software to measure cellularity and cell size. RESULTS: VERDICT parameters were successfully calculated in all patients. The imaging-derived results showed a larger intracellular volume fraction in high-grade glioma compared to low-grade glioma (0.13 ± 0.07 vs. 0.08 ± 0.02, respectively; p = 0.05) and a trend towards a smaller extracellular/vascular volume fraction (0.88 ± 0.07 vs. 0.92 ± 0.04, respectively; p = 0.10). The conventional apparent diffusion coefficient was higher in low-grade gliomas compared to high-grade gliomas, but this difference was not statistically significant (1.22 ± 0.13 × 10-3 mm2/s vs. 0.98 ± 0.38 × 10-3 mm2/s, respectively; p = 0.18). CONCLUSION: This feasibility study demonstrated that VERDICT MRI can be used to explore the tissue microstructure of glioma using an abbreviated protocol. The VERDICT parameters of tissue structure correlated with those derived on histology. The method shows promise as a potential test for diagnostic stratification and treatment response monitoring in the future. KEY POINTS: • VERDICT MRI is an advanced diffusion technique which has been correlated with histopathological findings obtained at surgery from patients with glioma in this study. • The intracellular volume fraction measured with VERDICT was larger in high-grade tumours compared to that in low-grade tumours. • The results were complementary to measurements from conventional diffusion-weighted imaging, and the technique could be performed in a clinically feasible timescale.

WINDOW consortium: A path towards increased therapy efficacy against glioblastoma.

Glioblastoma is the most common and malignant form of brain cancer, for which the standard treatment is maximal surgical resection, radiotherapy and chemotherapy. Despite these interventions, mean overall survival remains less than 15 months, during which extensive tumor infiltration throughout the brain occurs. The resulting metastasized cells in the brain are characterized by chemotherapy resistance and extensive intratumoral heterogeneity. An orthogonal approach attacking both intracellular resistance mechanisms as well as intercellular heterogeneity is necessary to halt tumor progression. For this reason, we established the WINDOW Consortium (Window for Improvement for Newly Diagnosed patients by Overcoming disease Worsening), in which we are establishing a strategy for rational selection and development of effective therapies against glioblastoma. Here, we overview the many challenges posed in treating glioblastoma, including selection of drug combinations that prevent therapy resistance, the need for drugs that have improved blood brain barrier penetration and strategies to counter heterogeneous cell populations within patients. Together, this forms the backbone of our strategy to attack glioblastoma.

Diabetes insipidus-an extremely rare complication from replacement of an external ventricular drain.

Insertion of an external ventricular drain (EVD) is one of the most common and most important lifesaving procedures encountered in the neurologic intensive care unit, but often done by the junior members of the team. A good number of complications may follow the insertion of EVD. In the available literature, only one case was reported with the placement of EVD in suprasellar cistern. There is no report of insertion or replacement of an EVD in the sella. Diabetes insipidus (DI) is also an unheard of complication of EVD. Here, we report a case where a patient with subarachnoid haemorrhage (SAH) with acute hydrocephalus needed CSF diversion and had an EVD, during replacement of which through the same tract, the new EVD went into the sellar floor and she developed diabetes insipidus (DI) eventually. The catheter was pulled out and the DI settled. DI may occur as a consequence of SAH. The rationale behind reporting this case is to differentiate the cause of DI; as following insertion of EVD in a patient of SAH, the development of DI should raise the suspicion of misplaced EVD, should not be left as a consequence of SAH and appropriate imaging should be obtained. To prevent this happening, preoperative verification of CT, image-guided insertion, measurement of the length of the tubing and careful anchorage of EVD to surrounding tissue are necessary.

Local alkylating chemotherapy applied immediately after 5-ALA guided resection of glioblastoma does not provide additional benefit.

Grade IV glioma is the most common and aggressive primary brain tumour. Gross total resection with 5-aminolevulinic acid (5-ALA) guided surgery combined with local chemotherapy (carmustine wafers) is an attractive treatment strategy in these patients. No previous studies have examined the benefit carmustine wafers in a treatment programme of 5-ALA guided resection followed by a temozolomide-based chemoradiotherapy protocol. The objective of this study was to examine the benefit of carmustine wafers on survival in patients undergoing 5-ALA guided resection. A retrospective cohort study of 260 patients who underwent 5-ALA resection of confirmed WHO 2007 Grade IV glioma between July 2009 and December 2014. Survival curves were calculated using the Kaplan-Meier method from surgery. The log-rank test was used to compare survival curves between groups. Cox regression was performed to identify variables predicting survival. A propensity score matched analysis was used to compare survival between patients who did and did not receive carmustine wafers while controlling for baseline characteristics. Propensity matched analysis showed no significant survival benefit of insertion of carmustine wafers over 5-ALA resection alone (HR 0.97 [0.68-1.26], p = 0.836). There was a trend to higher incidence of wound infection in those who received carmustine wafers (15.4 vs. 7.1%, p = 0.064). The Cox regression analysis showed that intraoperative residual fluorescent tumour and residual enhancing tumour on post-operative MRI were significantly predictive of reduced survival. Carmustine wafers have no added benefit following 5-ALA guided resection. Residual fluorescence and residual enhancing disease following resection have a negative impact on survival.

Intraoperative imaging technology to maximise extent of resection for glioma.

BACKGROUND: Extent of resection is considered to be a prognostic factor in neuro-oncology. Intraoperative imaging technologies are designed to help achieve this goal. It is not clear whether any of these sometimes very expensive tools (or their combination) should be recommended as standard care for people with brain tumours. We set out to determine if intraoperative imaging technology offers any advantage in terms of extent of resection over standard surgery and if any one technology was more effective than another. OBJECTIVES: To establish the overall effectiveness and safety of intraoperative imaging technology in resection of glioma. To supplement this review of effects, we also wished to identify cost analyses and economic evaluations as part of a Brief Economic Commentary (BEC). SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 7, 2017), MEDLINE (1946 to June, week 4, 2017), and Embase (1980 to 2017, week 27). We searched the reference lists of all identified studies. We handsearched two journals, the Journal of Neuro-Oncology and Neuro-oncology, from 1991 to 2017, including all conference abstracts. We contacted neuro-oncologists, trial authors, and manufacturers regarding ongoing and unpublished trials. SELECTION CRITERIA: Randomised controlled trials evaluating people of all ages with presumed new or recurrent glial tumours (of any location or histology) from clinical examination and imaging (computed tomography (CT) or magnetic resonance imaging (MRI), or both). Additional imaging modalities (e.g. positron emission tomography, magnetic resonance spectroscopy) were not mandatory. Interventions included intraoperative MRI (iMRI), fluorescence-guided surgery, ultrasound, and neuronavigation (with or without additional image processing, e.g. tractography). DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the search results for relevance, undertook critical appraisal according to known guidelines, and extracted data using a prespecified pro forma. MAIN RESULTS: We identified four randomised controlled trials, using different intraoperative imaging technologies: iMRI (2 trials including 58 and 14 participants, respectively); fluorescence-guided surgery with 5-aminolevulinic acid (5-ALA) (1 trial, 322 participants); and neuronavigation (1 trial, 45 participants). We identified one ongoing trial assessing iMRI with a planned sample size of 304 participants for which results are expected to be published around autumn 2018. We identified no trials for ultrasound.Meta-analysis was not appropriate due to differences in the tumours included (eloquent versus non-eloquent locations) and variations in the image guidance tools used in the control arms (usually selective utilisation of neuronavigation). There were significant concerns regarding risk of bias in all the included studies. All studies included people with high-grade glioma only.Extent of resection was increased in one trial of iMRI (risk ratio (RR) of incomplete resection 0.13, 95% confidence interval (CI) 0.02 to 0.96; 1 study, 49 participants; very low-quality evidence) and in the trial of 5-ALA (RR of incomplete resection 0.55, 95% CI 0.42 to 0.71; 1 study, 270 participants; low-quality evidence). The other trial assessing iMRI was stopped early after an unplanned interim analysis including 14 participants, therefore the trial provides very low-quality evidence. The trial of neuronavigation provided insufficient data to evaluate the effects on extent of resection.Reporting of adverse events was incomplete and suggestive of significant reporting bias (very low-quality evidence). Overall, reported events were low in most trials. There was no clear evidence of improvement in overall survival with 5-ALA (hazard ratio 0.83, 95% CI 0.62 to 1.07; 1 study, 270 participants; low-quality evidence). Progression-free survival data were not available in an appropriate format for analysis. Data for quality of life were only available for one study and suffered from significant attrition bias (very low-quality evidence). AUTHORS' CONCLUSIONS: Intra-operative imaging technologies, specifically iMRI and 5-ALA, may be of benefit in maximising extent of resection in participants with high grade glioma. However, this is based on low to very low quality evidence, and is therefore very uncertain. The short- and long-term neurological effects are uncertain. Effects of image-guided surgery on overall survival, progression-free survival, and quality of life are unclear. A brief economic commentary found limited economic evidence for the equivocal use of iMRI compared with conventional surgery. In terms of costs, a non-systematic review of economic studies suggested that compared with standard surgery use of image-guided surgery has an uncertain effect on costs and that 5-aminolevulinic acid was more costly. Further research, including studies of ultrasound-guided surgery, is needed.

European Association for Neuro-Oncology (EANO) guideline on the diagnosis and treatment of adult astrocytic and oligodendroglial gliomas.

The European Association for Neuro-Oncology guideline provides recommendations for the clinical care of adult patients with astrocytic and oligodendroglial gliomas, including glioblastomas. The guideline is based on the 2016 WHO classification of tumours of the central nervous system and on scientific developments since the 2014 guideline. The recommendations focus on pathological and radiological diagnostics, and the main treatment modalities of surgery, radiotherapy, and pharmacotherapy. In this guideline we have also integrated the results from contemporary clinical trials that have changed clinical practice. The guideline aims to provide guidance for diagnostic and management decisions, while limiting unnecessary treatments and costs. The recommendations are a resource for professionals involved in the management of patients with glioma, for patients and caregivers, and for health-care providers in Europe. The implementation of this guideline requires multidisciplinary structures of care, and defined processes of diagnosis and treatment.

The PDK1-Rsk Signaling Pathway Controls Langerhans Cell Proliferation and Patterning.

Langerhans cells (LC), the dendritic cells of the epidermis, are distributed in a distinctive regularly spaced array. In the mouse, the LC array is established in the first few days of life from proliferating local precursors, but the regulating signaling pathways are not fully understood. We found that mice lacking the kinase phosphoinositide-dependent kinase 1 selectively lack LC. Deletion of the phosphoinositide-dependent kinase 1 target kinases, ribosomal S6 kinase 1 (Rsk1) and Rsk2, produced a striking perturbation in the LC network: LC density was reduced 2-fold, but LC size was increased by the same magnitude. Reduced LC numbers in Rsk1/2(-/-) mice was not due to accelerated emigration from the skin but rather to reduced proliferation at least in adults. Rsk1/2 were required for normal LC patterning in neonates, but not when LC were ablated in adults and replaced by bone marrow-derived cells. Increased LC size was an intrinsic response to reduced LC numbers, reversible on LC emigration, and could be observed in wild type epidermis where LC size also correlated inversely with LC density. Our results identify a key signaling pathway needed to establish a normal LC network and suggest that LC might maintain epidermal surveillance by increasing their "footprint" when their numbers are limited.

A crucial role for ß2 integrins in podosome formation, dynamics and Toll-like-receptor-signaled disassembly in dendritic cells.

The dynamic properties of podosomes, their ability to degrade the underlying matrix and their modulation by Toll-like receptor (TLR) signaling in dendritic cells (DCs) suggests they have an important role in migration. Integrins are thought to participate in formation and dynamics of podosomes but the multiplicity of integrins in podosomes has made this difficult to assess. We report that murine DCs that lack ß2 integrins fail to form podosomes. Re-expression of ß2 integrins restored podosomes but not when the membrane proximal or distal NPxF motifs, or when an intervening triplet of threonine residues were mutated. We show that ß2 integrins are remarkably long-lived in podosome clusters and form a persistent framework that hosts multiple actin-core-formation events at the same or adjacent sites. When ß2 integrin amino acid residues 745 or 756 were mutated from Ser to Ala, podosomes became resistant to dissolution mediated through TLR signaling. TLR signaling did not detectably modulate phosphorylation at these sites but mutation of either residue to phospho-mimetic Asp increased ß2 integrin turnover in podosomes, indicating that phosphorylation at one or both sites establishes permissive conditions for TLR-signaled podosome disassembly.

Neuroprotective actions of PIKE-L by inhibition of SET proteolytic degradation by asparagine endopeptidase.

Ischemia and seizure cause excessive neuronal excitation that is associated with brain acidosis and neuronal cell death. However, the molecular mechanism of acidification-triggered neuronal injury is incompletely understood. Here, we show that asparagine endopeptidase (AEP) is activated under acidic condition, cuts SET, an inhibitor of DNase, and triggers DNA damage in brain, which is inhibited by PIKE-L. SET, a substrate of caspases, was cleaved by acidic cytosolic extract independent of caspase activation. Fractionation of the acidic cellular extract yielded AEP that is required for SET cleavage. We found that kainate provoked AEP activation and SET cleavage at N175, triggering DNA nicking in wild-type, but not AEP null, mice. PIKE-L strongly bound SET and prevented its degradation by AEP, leading to resistance of neuronal cell death. Moreover, AEP also mediated stroke-provoked SET cleavage and cell death in brain. Thus, AEP might be one of the proteinases activated by acidosis triggering neuronal injury during neuroexcitotoxicity or ischemia.

Intratumor heterogeneity in human glioblastoma reflects cancer evolutionary dynamics.

Glioblastoma (GB) is the most common and aggressive primary brain malignancy, with poor prognosis and a lack of effective therapeutic options. Accumulating evidence suggests that intratumor heterogeneity likely is the key to understanding treatment failure. However, the extent of intratumor heterogeneity as a result of tumor evolution is still poorly understood. To address this, we developed a unique surgical multisampling scheme to collect spatially distinct tumor fragments from 11 GB patients. We present an integrated genomic analysis that uncovers extensive intratumor heterogeneity, with most patients displaying different GB subtypes within the same tumor. Moreover, we reconstructed the phylogeny of the fragments for each patient, identifying copy number alterations in EGFR and CDKN2A/B/p14ARF as early events, and aberrations in PDGFRA and PTEN as later events during cancer progression. We also characterized the clonal organization of each tumor fragment at the single-molecule level, detecting multiple coexisting cell lineages. Our results reveal the genome-wide architecture of intratumor variability in GB across multiple spatial scales and patient-specific patterns of cancer evolution, with consequences for treatment design.