Genetic pathways to primary and secondary glioblastoma

Behavior-Oriented Nomogram for the Stratification of Lower-Grade Gliomas to Improve Individualized Treatment

Secondary glioblastomas (sGBM) are derived from previously lower-grade [World Health Organization (WHO) grades II or III] gliomas. Lower-grade benign-behaving gliomas may retain their former grade following recurrence, or may become malignant higher-grade glioblastomas. Prediction of tumor behavior in lower-grade gliomas is critical for individualized glioma therapy. A total of 89 patients were included between January 2000 and January 2019 in the present study to establish a nomogram via univariate and multivariate logistic regression analyses. Nomogram predictive performance was tested in the validation group. We then analyzed 36 O-6-methylguanine-DNA methyltransferase (MGMT) unmethylated lower-grade gliomas from patients seen at West China Hospital of Sichuan University. Survival statistics were calculated with the Kaplan-Meier method. Two clinical factors (molecular diagnosis and WHO grade), five radiological factors (location, cortical involvement, multicentricity, uniformity, and margin enhancement), one biomarker (1p19q codeletion), and a combination of three biomarkers (IDH+/ATRX-/TP53-) were associated with glioma upgrading. Nomograms positive for these prognostic factors had an AUC of 0.880 in the derivation group and 0.857 in the validation group. The calibration and score-stratified survival curves for the derivation group and validation group were good. An operational nomogram was published at https://warrenwrl.shinyapps.io/DynNomapp/. The overall survival of secondary gliomas in the MGMT-unmethylated cohort were influenced independently by the use of temozolomide during the treatment of formerly low-grade gliomas (p=0.00096). Clinical and radiological factors and biomarker-based behavior-oriented nomograms may offer a feasible identification tool for the detection of sGBM precursors. This method may further assist neurosurgeons with the stratification of lower-grade glioma cases and thus the development of better, more individualized treatment plans.

Correlation of genetic alterations by whole-exome sequencing with clinical outcomes of glioblastoma patients from the Lebanese population

Introduction

Glioblastoma (GBM) is an aggressive brain tumor associated with high degree of resistance to treatment. Given its heterogeneity, it is important to understand the molecular landscape of this tumor for the development of more effective therapies. Because of the different genetic profiles of patients with GBM, we sought to identify genetic variants in Lebanese patients with GBM (LEB-GBM) and compare our findings to those in the Cancer Genome Atlas (TCGA).

Methods

We performed whole exome sequencing (WES) to identify somatic variants in a cohort of 60 patient-derived GBM samples. We focused our analysis on 50 commonly mutated GBM candidate genes and compared mutation signatures between our population and publicly available GBM data from TCGA. We also cross-tabulated biological covariates to assess for associations with overall survival, time to recurrence and follow-up duration.

Results

We included 60 patient-derived GBM samples from 37 males and 23 females, with age ranging from 3 to 80 years (mean and median age at diagnosis were 51 and 56, respectively). Recurrent tumor formation was present in 94.8% of patients (n = 55/58). After filtering, we identified 360 somatic variants from 60 GBM patient samples. After filtering, we identified 360 somatic variants from 60 GBM patient samples. Most frequently mutated genes in our samples included ATRX, PCDHX11, PTEN, TP53, NF1, EGFR, PIK3CA, and SCN9A. Mutations in NLRP5 were associated with decreased overall survival among the Lebanese GBM cohort (p = 0.002). Mutations in NLRP5 were associated with decreased overall survival among the Lebanese GBM cohort (p = 0.002). EGFR and NF1 mutations were associated with the frontal lobe and temporal lobe in our LEB-GBM cohort, respectively.

Conclusions

Our WES analysis confirmed the similarity in mutation signature of the LEB-GBM population with TCGA cohorts. It showed that 1 out of the 50 commonly GBM candidate gene mutations is associated with decreased overall survival among the Lebanese cohort. This study also highlights the need for studies with larger sample sizes to inform clinicians for better prognostication and management of Lebanese patients with GBM.

Identification of Systems Level Molecular Signatures from Glioblastoma Multiforme Derived Extracellular Vesicles

Glioblastoma multiforme (GBM) is one of the most lethal malignancies of the central nervous system characterized by high mortality rate. The complexity of GBM pathogenesis, progression, and prognosis is not fully understood yet. GBM-derived extracellular vesicles (EVs) carry several oncogenic elements that facilitate GBM progression. The purpose of this study was to identify systems level molecular signatures from GBM-derived EVs using integrative analysis of publicly available transcriptomic data generated from plasma and serum samples. The dataset contained 19 samples in total, of which 15 samples were from plasma (11 GBM patients and 4 healthy samples) and 4 samples were from serum (2 GBM and 2 healthy samples). We carried out statistical analysis to identify differentially expressed genes (DEGs), functional enrichment analysis of the DEGs, protein-protein interaction networks, module analysis, transcription factors and target gene regulatory networks analysis, and identification of hub genes. The differential expression of the identified hub genes were validated with the independent TCGA-GBM dataset. We have identified a few crucial genes and pathways associated with GBM prognosis and therapy resistance. The DEGs identified from plasma were associated with inflammatory processes and viral infection. On the other hand, the hub genes identified from the serum samples were significantly associated with protein ubiquitinylation processes and cytokine signaling regulation. The findings indicate that GBM-derived plasma and serum DEGs may be associated with distinct cellular processes and pathways which facilitate GBM progression. The findings will provide better understanding of the molecular mechanisms of GBM pathogenesis and progression. These results can further be utilized for developing and validating minimally invasive diagnostic and therapeutic molecular biomarkers for GBM.

Identification of New Genetic Clusters in Glioblastoma Multiforme: EGFR Status and ADD3 Losses Influence Prognosis

Glioblastoma multiforme (GB) is one of the most aggressive tumors. Despite continuous efforts to improve its clinical management, there is still no strategy to avoid a rapid and fatal outcome. EGFR amplification is the most characteristic alteration of these tumors. Although effective therapy against it has not yet been found in GB, it may be central to classifying patients. We investigated somatic-copy number alterations (SCNA) by multiplex ligation-dependent probe amplification in a series of 137 GB, together with the detection of EGFRvIII and FISH analysis for EGFR amplification. Publicly available data from 604 patients were used as a validation cohort. We found statistical associations between EGFR amplification and/or EGFRvIII, and SCNA in CDKN2A, MSH6, MTAP and ADD3. Interestingly, we found that both EGFRvIII and losses on ADD3 were independent markers of bad prognosis (p = 0.028 and 0.014, respectively). Finally, we got an unsupervised hierarchical classification that differentiated three clusters of patients based on their genetic alterations. It offered a landscape of EGFR co-alterations that may improve the comprehension of the mechanisms underlying GB aggressiveness. Our findings can help in defining different genetic profiles, which is necessary to develop new and different approaches in the management of our patients.

Discovering and interpreting transcriptomic drivers of imaging traits using neural networks

MOTIVATION

Cancer heterogeneity is observed at multiple biological levels. To improve our understanding of these differences and their relevance in medicine, approaches to link organ- and tissue-level information from diagnostic images and cellular-level information from genomics are needed. However, these 'radiogenomic' studies often use linear or shallow models, depend on feature selection, or consider one gene at a time to map images to genes. Moreover, no study has systematically attempted to understand the molecular basis of imaging traits based on the interpretation of what the neural network has learned. These studies are thus limited in their ability to understand the transcriptomic drivers of imaging traits, which could provide additional context for determining clinical outcomes.

RESULTS

We present a neural network-based approach that takes high-dimensional gene expression data as input and performs non-linear mapping to an imaging trait. To interpret the models, we propose gene masking and gene saliency to extract learned relationships from radiogenomic neural networks. In glioblastoma patients, our models outperformed comparable classifiers (>0.10 AUC) and our interpretation methods were validated using a similar model to identify known relationships between genes and molecular subtypes. We found that tumor imaging traits had specific transcription patterns, e.g. edema and genes related to cellular invasion, and 10 radiogenomic traits were significantly predictive of survival. We demonstrate that neural networks can model transcriptomic heterogeneity to reflect differences in imaging and can be used to derive radiogenomic traits with clinical value.

AVAILABILITY AND IMPLEMENTATION

https://github.com/novasmedley/deepRadiogenomics.

CONTACT

whsu@mednet.ucla.edu.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Discovery of a dual inhibitor of NQO1 and GSTP1 for treating glioblastoma

BACKGROUND

Glioblastoma (GBM) is a universally lethal tumor with frequently overexpressed or mutated epidermal growth factor receptor (EGFR). NADPH quinone oxidoreductase 1 (NQO1) and glutathione-S-transferase Pi 1 (GSTP1) are commonly upregulated in GBM. NQO1 and GSTP1 decrease the formation of reactive oxygen species (ROS), which mediates the oxidative stress and promotes GBM cell proliferation.

METHODS

High-throughput screen was used for agents selectively active against GBM cells with EGFRvIII mutations. Co-crystal structures were revealed molecular details of target recognition. Pharmacological and gene knockdown/overexpression approaches were used to investigate the oxidative stress in vitro and in vivo.

RESULTS

We identified a small molecular inhibitor, "MNPC," that binds to both NQO1 and GSTP1 with high affinity and selectivity. MNPC inhibits NQO1 and GSTP1 enzymes and induces apoptosis in GBM, specifically inhibiting the growth of cell lines and primary GBM bearing the EGFRvIII mutation. Co-crystal structures between MNPC and NQO1, and molecular docking of MNPC with GSTP1 reveal that it binds the active sites and acts as a potent dual inhibitor. Inactivation of both NQO1 and GSTP1 with siRNA or MNPC results in imbalanced redox homeostasis, leading to apoptosis and mitigated cancer proliferation in vitro and in vivo.

CONCLUSIONS

Thus, MNPC, a dual inhibitor for both NQO1 and GSTP1, provides a novel lead compound for treating GBM via the exploitation of specific vulnerabilities created by mutant EGFR.

Extracranial metastases in secondary glioblastoma multiforme: a case report

Background

Glioblastoma (GBM) is known for its devastating intracranial infiltration and its unfavorable prognosis, while extracranial involvement is a very rare event, more commonly attributed to IDH wild-type (primary) GBM evolution.

Case presentation

We present a case of a young woman with a World Health Organization (WHO) grade II Astrocytoma evolved to WHO grade IV IDH mutant glioblastoma, with subsequent development of lymphatic and bone metastases, despite the favorable biomolecular pattern and the stability of the primary brain lesion.

Conclusions

Our case highlights that grade II Astrocytoma may evolve to a GBM and rarely lead to a secondary metastatic diffusion, which can progress quite rapidly; any symptoms referable to a possible systemic involvement should be carefully investigated.

Endothelial-Tumor Cell Interaction in Brain and CNS Malignancies

Glioblastoma and other brain or CNS malignancies (like neuroblastoma and medulloblastoma) are difficult to treat and are characterized by excessive vascularization that favors further tumor growth. Since the mean overall survival of these types of diseases is low, the finding of new therapeutic approaches is imperative. In this review, we discuss the importance of the interaction between the endothelium and the tumor cells in brain and CNS malignancies. The different mechanisms of formation of new vessels that supply the tumor with nutrients are discussed. We also describe how the tumor cells (TC) alter the endothelial cell (EC) physiology in a way that favors tumorigenesis. In particular, mechanisms of EC-TC interaction are described such as (a) communication using secreted growth factors (i.e., VEGF, TGF-β), (b) intercellular communication through gap junctions (i.e., Cx43), and (c) indirect interaction via intermediate cell types (pericytes, astrocytes, neurons, and immune cells). At the signaling level, we outline the role of important mediators, like the gasotransmitter nitric oxide and different types of reactive oxygen species and the systems producing them. Finally, we briefly discuss the current antiangiogenic therapies used against brain and CNS tumors and the potential of new pharmacological interventions that target the EC-TC interaction.

SOI-Nanowire Biosensor for the Detection of Glioma-Associated miRNAs in Plasma

Herein, we report the development of a highly sensitive nanotechnology-based system—silicon-on-insulator nanowire biosensor for the revelation of microRNAs (miRNAs), associated with the development of glioma in the human. In this system, a sensor chip, bearing an array of silicon nanowire structures, is employed. The sensor chip is fabricated using a top-down technology. In our experiments reported herein, we demonstrated the detection of DNA oligonucleotide (oDNA), which represents a synthetic analogue of microRNA-363 associated with the development of glioma. To provide biospecific detection of the target oligonucleotides, the surface of the nanowire structures is modified with oligonucleotide probes; the latter are complementary to the target ones. The concentration limit of the target oligonucleotide detection, attained using our nanowire biosensor, is at the level of DL~10−17 M. The revelation of the elevated level of glioma-associated miRNA in plasma is also demonstrated.

Multidisciplinary Therapy Managed Recurrent Glioblastoma in a BRAF-V600E Mutant Pregnant Female: A Case Report and Review of the Literature

Background: Glioblastoma (GBM) is the most malignant intracranial tumor in adults. However, the overall management of GBM in pregnancy is rarely reported. How to balance the therapeutic benefits to the mother and risks to the fetus remains hugely challenging for clinicians. The application of specific targeting therapy combined with conventional treatment sheds light on a longer lifetime for the patients suffering from GBM. Case Presentation: We present a pregnant female at 20 weeks gestation diagnosed with GBM. Surgical resection was initially performed without adjuvant therapy, and the tumor recurred de novo 2 months later. A secondary craniotomy and cesarean section were performed simultaneously at 32 weeks gestation, both the patient and infant were survived. She was subsequently treated with traditional chemo-radiotherapy. No other identified genetic alterations indicating an optimistic prognosis were detected except for BRAF V600E mutation. Thus, the BRAF inhibitor was placed on her with achieving a good clinical outcome of more than 2-year survival without recurrence. Conclusion: Personalized multidisciplinary therapy should be considered when GBMs occur in pregnancy. Response to the therapy in this presenting case suggests that BRAF V600E mutation is a favorable biomarker for GBM. The mortality of GBM might be reduced through genetic testing and targeted treatment. However, more studies must be conducted to confirm our observation.

Valganciclovir as Add-On to Standard Therapy in Secondary Glioblastoma

Patients with glioblastoma have a very poor prognosis despite aggressive therapeutic strategies. Cytomegalovirus has been detected in >90% of glioblastoma tumors. This virus can affect tumor progression and may represent a novel glioblastoma therapy target. We report, here, a retrospective survival analysis of patients with secondary glioblastoma who were treated with the anti-viral drug valganciclovir at Karolinska University Hospital in Stockholm. We performed survival analyses of eight patients with secondary glioblastoma who were treated with a standard dose of valganciclovir as an add-on to second-line therapy after their disease progression to glioblastoma. Thirty-six patients with secondary glioblastoma admitted during the same time period who received similar treatment and care served as contemporary controls. The patients treated with valganciclovir showed an increased median overall survival after progression to glioblastoma compared with controls (19.1 versus 12.7 months, p = 0.0072). This result indicates a potential positive effect of valganciclovir in secondary glioblastoma, which is in agreement with our previous observation that valganciclovir treatment improves the outcomes of patients with newly diagnosed glioblastoma. Larger randomized studies are warranted to prove this hypothesis.

Non-coding RNAs in Brain Tumors, the Contribution of lncRNAs, circRNAs, and snoRNAs to Cancer Development-Their Diagnostic and Therapeutic Potential

Brain tumors are one of the most frightening ailments that afflict human beings worldwide. They are among the most lethal of all adult and pediatric solid tumors. The unique cell-intrinsic and microenvironmental properties of neural tissues are some of the most critical obstacles that researchers face in the diagnosis and treatment of brain tumors. Intensifying the search for potential new molecular markers in order to develop new effective treatments for patients might resolve this issue. Recently, the world of non-coding RNAs (ncRNAs) has become a field of intensive research since the discovery of their essential impact on carcinogenesis. Some of the most promising diagnostic and therapeutic regulatory RNAs are long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and small nucleolar RNAs (snoRNAs). Many recent reports indicate the important role of these molecules in brain tumor development, as well as their implications in metastasis. In the following review, we summarize the current state of knowledge about regulatory RNAs, namely lncRNA, circRNAs, and snoRNAs, and their impact on the development of brain tumors in children and adults with particular emphasis on malignant primary brain tumors-gliomas and medulloblastomas (MB). We also provide an overview of how these different ncRNAs may act as biomarkers in these tumors and we present their potential clinical implications.

Checkpoint inhibitor immunotherapy for glioblastoma: current progress, challenges and future outlook

INTRODUCTION

Despite maximal surgical resection and chemoradiation, glioblastoma (GBM) continues to be associated with significant morbidity and mortality. Novel therapeutic strategies are urgently needed. Given success in treating multiple other forms of cancer, checkpoint inhibitor immunotherapy remains foremost amongst novel therapeutic strategies that are currently under investigation.

AREAS COVERED

Through a systematic review of both published literature and the latest preliminary data available from ongoing clinical studies, we provide an up-to-date discussion on the immune system in the CNS, a detailed mechanistic evaluation of checkpoint biology in the CNS along with evidence for disruption of these pathways in GBM, and a summary of available preclinical and clinical data for checkpoint blockade in GBM. We also include a discussion of novel, emerging targets for checkpoint blockade which may play an important role in GBM immunotherapy.

EXPERT OPINION

Evidence indicates that while clinical success of checkpoint blockade for the treatment of GBM has been limited to date, through improved preclinical models, optimization in the context of standard of care therapies, assay standardization and harmonization, and combinatorial approaches which may include novel targets for checkpoint blockade, checkpoint inhibitor immunotherapy may yield a safe and effective therapeutic option for the treatment of GBM.

New hints towards a precision medicine strategy for IDH wild-type glioblastoma

Glioblastoma represents the most common primary malignancy of the central nervous system in adults and remains a largely incurable disease. The elucidation of disease subtypes based on mutational profiling, gene expression and DNA methylation has so far failed to translate into improved clinical outcomes. However, new knowledge emerging from the subtyping effort in the IDH-wild-type setting may provide directions for future precision therapies. Here, we review recent learnings in the field, and further consider how tumour microenvironment differences across subtypes may reveal novel contexts of vulnerability. We discuss recent treatment approaches and ongoing trials in the IDH-wild-type glioblastoma setting, and propose an integrated discovery stratagem incorporating multi-omics, single-cell technologies and computational approaches.

Current Opinion on Molecular Characterization for GBM Classification in Guiding Clinical Diagnosis, Prognosis, and Therapy

Glioblastoma (GBM) is highly invasive and the deadliest brain tumor in adults. It is characterized by inter-tumor and intra-tumor heterogeneity, short patient survival, and lack of effective treatment. Prognosis and therapy selection is driven by molecular data from gene transcription, genetic alterations and DNA methylation. The four GBM molecular subtypes are proneural, neural, classical, and mesenchymal. More effective personalized therapy heavily depends on higher resolution molecular subtype signatures, combined with gene therapy, immunotherapy and organoid technology. In this review, we summarize the principal GBM molecular classifications that guide diagnosis, prognosis, and therapeutic recommendations.

Ethnic delineation of primary glioblastoma genome

Glioblastoma (GBM) is the most malignant primary brain tumor in adults with substantial genomic alterations. The median survival is approximately 14.6 months, despite aggressive therapeutic intervention, which comprised of surgical resection, radiotherapy, and chemotherapy. Recent studies on cancer genomic have revealed crucial insights into dynamic molecular subgroups within GBM, which govern distinct clinical response and sensitivity of each individual to therapy. In the present study, we analyzed genomic composition of primary GBMs between two ethnic groups [IRCR (Institute of Refractory Cancer Research), and TCGA (The Cancer Genome Atlats)] to explore genomic and molecular features that constitute malignant behavior of glioblastoma based on distinct ethnicity. We identified enrichments of MAPK and p53 pathways in IRCR patients, while aberrant activation of Receptor Tyrosine Kinases (RTKs) were predominant in TCGA cohort. We also discovered differential clinical prognosis between two groups and explored essential features that present such diversity.

Multifaceted transforming growth factor-beta (TGFβ) signalling in glioblastoma

Glioblastoma (GBM) is an aggressive and devastating primary brain cancer which responds very poorly to treatment. The average survival time of patients is only 14-15 months from diagnosis so there is a clear and unmet need for the development of novel targeted therapies to improve patient outcomes. The multifunctional cytokine TGFβ plays fundamental roles in development, adult tissue homeostasis, tissue wound repair and immune responses. Dysfunction of TGFβ signalling has been implicated in both the development and progression of many tumour types including GBM, thereby potentially providing an actionable target for its treatment. This review will examine TGFβ signalling mechanisms and their role in the development and progression of GBM. The targeting of TGFβ signalling using a variety of approaches including the TGFβ binding protein Decorin will be highlighted as attractive therapeutic strategies.

Apoptosis related microRNAs and MGMT in glioblastoma cell lines submitted to treatments with ionizing radiation and temozolomide

Aim

To evaluate the effect of radiotherapy and temozolomide on the expression of miRNAs apoptotic (miRNAs-21, -221, -222 (anti-apoptotic) and miRNAs-15a, -16 (pro-apoptotic)) and the gene MGMT in glioblastoma cell lines.

Background

The limited knowledge of the molecular biology of malignant gliomas may hinder the development of therapeutic modalities. In this scenario, one of the greatest advances of recent years was the identification of microRNAs. These molecules have an important role in biological processes involving cancer, including glioblastoma.

Materials and methods

Trypan blue was used to verify the cell viability, and real time PCR to quantify the expression of microRNAs and gene 24, 48 and 120 h after exposure to treatments.

Results

There was a statistically significant decrease of expression of miR-15a between 48 and 120 h in line T98 G treated with radiation, increased expression of miR-15a between 24 and 120 h in line U251 treated with radiation and temozolomide, and increased expression of miR-16 between 24 and 120 h in line U251 treated with radiation alone and when combined with temozolomide. There was a decrease in MGMT gene expression, between 24 and 48 h in U343 cells treated with temozolomide.

Conclusions

Ionizing radiation and temozolomide modified the expression of miRNAs studied and MGMT.

A fully automated artificial intelligence method for non-invasive, imaging-based identification of genetic alterations in glioblastomas

Glioblastoma is the most common malignant brain parenchymal tumor yet remains challenging to treat. The current standard of care-resection and chemoradiation-is limited in part due to the genetic heterogeneity of glioblastoma. Previous studies have identified several tumor genetic biomarkers that are frequently present in glioblastoma and can alter clinical management. Currently, genetic biomarker status is confirmed with tissue sampling, which is costly and only available after tumor resection or biopsy. The purpose of this study was to evaluate a fully automated artificial intelligence approach for predicting the status of several common glioblastoma genetic biomarkers on preoperative MRI. We retrospectively analyzed multisequence preoperative brain MRI from 199 adult patients with glioblastoma who subsequently underwent tumor resection and genetic testing. Radiomics features extracted from fully automated deep learning-based tumor segmentations were used to predict nine common glioblastoma genetic biomarkers with random forest regression. The proposed fully automated method was useful for predicting IDH mutations (sensitivity = 0.93, specificity = 0.88), ATRX mutations (sensitivity = 0.94, specificity = 0.92), chromosome 7/10 aneuploidies (sensitivity = 0.90, specificity = 0.88), and CDKN2 family mutations (sensitivity = 0.76, specificity = 0.86).

The Role of Liquid Biopsies in Detecting Molecular Tumor Biomarkers in Brain Cancer Patients

Glioblastoma multiforme (GBM) is one of the most lethal primary central nervous system cancers with a median overall survival of only 12-15 months. The best documented treatment is surgical tumor debulking followed by chemoradiation and adjuvant chemotherapy with temozolomide, but treatment resistance and therefore tumor recurrence, is the usual outcome. Although advances in molecular subtyping suggests GBM can be classified into four subtypes, one concern about using the original histology for subsequent treatment decisions is that it only provides a static snapshot of heterogeneous tumors that may undergo longitudinal changes over time, especially under selective pressure of ongoing therapy. Liquid biopsies obtained from bodily fluids like blood and cerebro-spinal fluid (CSF) are less invasive, and more easily repeated than surgery. However, their deployment for patients with brain cancer is only emerging, and possibly suppressed clinically due to the ongoing belief that the blood brain barrier prevents the egress of circulating tumor cells, exosomes, and circulating tumor nucleic acids into the bloodstream. Although brain cancer liquid biopsy analyses appear indeed challenging, advances have been made and here we evaluate the current literature on the use of liquid biopsies for detection of clinically relevant biomarkers in GBM to aid diagnosis and prognostication.

Molecular analyses of glioblastoma stem-like cells and glioblastoma tissue

Glioblastoma is a common, malignant brain tumor whose disease incidence increases with age. Glioblastoma stem-like cells (GSCs) are thought to contribute to cancer therapy resistance and to be responsible for tumor initiation, maintenance, and recurrence. This study utilizes both SNP array and gene expression profiling to better understand GSCs and their relation to malignant disease. Peripheral blood and primary glioblastoma tumor tissue were obtained from patients, the latter of which was used to generate GSCs as well as a CD133^pos./CD15^pos. subpopulation. The stem cell features of GSCs were confirmed via the immunofluorescent expression of Nestin, SOX2, and CD133. Both tumor tissue and the isolated primary cells shared unique abnormal genomic characteristics, including a gain of chromosome 7 as well as either a partial or complete loss of chromosome 10. Individual genomic differences were also observed, including the loss of chromosome 4 and segmental uniparental disomy of 9p24.3→p21.3 in GSCs. Gene expression profiling revealed 418 genes upregulated in tumor tissue vs. CD133^pos./CD15^pos. cells and 44 genes upregulated in CD133^pos./CD15^pos. cells vs. tumor tissue. Pathway analyses demonstrated that upregulated genes in CD133^pos./CD15^pos. cells are relevant to cell cycle processes and cancerogenesis. In summary, we detected previously undescribed genomic and gene expression differences when comparing tumor tissue and isolated stem-like subpopulations.

The Role of Selected Chemokines and Their Receptors in the Development of Gliomas

Among heterogeneous primary tumors of the central nervous system (CNS), gliomas are the most frequent type, with glioblastoma multiforme (GBM) characterized with the worst prognosis. In their development, certain chemokine/receptor axes play important roles and promote proliferation, survival, metastasis, and neoangiogenesis. However, little is known about the significance of atypical receptors for chemokines (ACKRs) in these tumors. The objective of the study was to present the role of chemokines and their conventional and atypical receptors in CNS tumors. Therefore, we performed a thorough search for literature concerning our investigation via the PubMed database. We describe biological functions of chemokines/chemokine receptors from various groups and their significance in carcinogenesis, cancer-related inflammation, neo-angiogenesis, tumor growth, and metastasis. Furthermore, we discuss the role of chemokines in glioma development, with particular regard to their function in the transition from low-grade to high-grade tumors and angiogenic switch. We also depict various chemokine/receptor axes, such as CXCL8-CXCR1/2, CXCL12-CXCR4, CXCL16-CXCR6, CX3CL1-CX3CR1, CCL2-CCR2, and CCL5-CCR5 of special importance in gliomas, as well as atypical chemokine receptors ACKR1-4, CCRL2, and PITPMN3. Additionally, the diagnostic significance and usefulness of the measurement of some chemokines and their receptors in the blood and cerebrospinal fluid (CSF) of glioma patients is also presented.

The Essentials of Molecular Testing in CNS Tumors: What to Order and How to Integrate Results

PURPOSE OF REVIEW

Molecular testing has become essential for the optimal workup of central nervous system (CNS) tumors. There is a vast array of testing from which to choose, and it can sometimes be challenging to appropriately incorporate findings into an integrated report. This article reviews various molecular tests and provides a concise overview of the most important molecular findings in the most commonly encountered CNS tumors.

RECENT FINDINGS

Many molecular alterations in CNS tumors have been identified over recent years, some of which are incorporated into the 2016 World Health Organization (WHO) classification and the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy-Not Official WHO (cIMPACT-NOW) updates. Array-based methylation profiling has emerged over the past couple of years and will likely replace much of currently used ancillary testing for diagnostic purposes. A combination of next-generation sequencing (NGS) panel and copy number array is ideal for diffuse gliomas and embryonal tumors, with a low threshold to employ in other tumor types. With the recent advances in molecular diagnostics, it will be ever more important for the pathologist to recognize the molecular testing available, which tests to perform, and to appropriately integrate results in light of clinical, radiologic, and histologic findings.

C/EBPβ mediates NQO1 and GSTP1 anti-oxidative reductases expression in glioblastoma, promoting brain tumor proliferation

Glioblastoma (GBM) is the most common and most aggressive brain tumor, associated with high levels of reactive oxidative species (ROS) due to metabolic and signaling aberrations. High ROS levels are detrimental to cells, but it remains incompletely understood how cancer cells cope with the adverse effects. Here we show that C/EBPβ, a ROS responsive transcription factor, regulates the transcription of NQO1 and GSTP1, two antioxidative reductases, which neutralize ROS in the GBM and mediates their proliferation. C/EBPβ is upregulated in EGFR overexpressed GBM cells, inversely correlated with the survival rates of brain tumor patients. Interestingly, C/EBPβ binds the promoters of NQO1 and GSTP1 and escalates their expression. Overexpression of C/EBPβ selectively decreases the ROS in EGFR-overexpressed U87MG cells and promotes cell proliferation via upregulating NQO1 and GSTP1; whereas knocking down C/EBPβ elevates the ROS and reduces proliferation by repressing the reductases. Accordingly, C/EBPβ mediates the brain tumor growth in vivo, coupling with NQO1 and GSTP1 expression and ROS levels. Hence, C/EBPβ regulates the expression of antioxidative reductases and balances the ROS, promoting brain tumor proliferation.

PEAMOtecan, a novel chronotherapeutic polymeric drug for brain cancer

Glioblastoma multiforme (GBM) is an aggressive and difficult to treat form of brain cancer. In this work, we report on a novel chronotherapeutic polymeric drug, PEAMOtecan, for GBM therapy. PEAMOtecan was synthesized by conjugating camptothecin, a topoisomerase I inhibitor, to our proprietary, 'clickable' and modular polyoxetane polymer platform consisting of acetylene-functionalized 3-ethyl-3-(hydroxymethyl)oxetane (EAMO) repeat units (Patent No.: US 9,421,276) via the linker 3,3'-dithiodipropionic acid (DDPA) with a disulfide bond (SS) extended by short-chain polyethylene glycol (PEG). We show that PEAMOtecan is a highly modular polymer nanoformulation that protects covalently bound CPT until slowly being released over extended periods of time dependent on the cleavage of the disulfide and ester linkages. PEAMOtecan kills glioma cells by mitotic catastrophe with p53 mutant/knockdown cells being more sensitive than matched wild type cells potentially providing cancer-specific targeting. To establish proof-of-principle therapeutic effects, we tested PEAMOtecan as monotherapy for efficacy in a mouse orthotopic glioma model. PEAMOtecan was administered by one-time, convection-enhanced delivery (CED) intra-tumorally to achieve superior distribution and extended drug release over time. In addition, the near-infrared (NIR) dye Cy5.5 was coupled to the polymer providing live-animal imaging capability to track tissue distribution and clearance of the injected polymer over time. We show that PEAMOtecan significantly improves the survival of mice harboring intra-cranial tumors (p = .0074 compared to untreated group). Altogether, these results support further development and testing of our nanoconjugate platform.

Advances in Diagnostic Immunohistochemistry for Primary Tumors of the Central Nervous System

As genomic characterization becomes increasingly necessary for accurate diagnosis of tumors of the central nervous system, identification of rapidly assessible biomarkers is equally important to avoid excessive cost and delay in initiation of therapy. This article reviews novel immunohistochemical markers that may be used to determine mutation status, activation of signaling pathways, druggable targets, and cell lineage in many diverse tumor types. In particular, recently added entities to the 2016 WHO classification of central nervous system tumors will be addressed, including IDH-mutant gliomas, diffuse midline glioma, epithelioid glioblastoma, angiocentric glioma, RELA-rearranged ependymoma, embryonal tumors (medulloblastoma, atypical teratoid/rhabdoid tumor, pineoblastoma, embryonal tumor with multilayered rosettes, and other genetically defined high-grade neuroepithelial tumors), and meningiomas associated with germline alterations.

The Role of miRNA for the Treatment of MGMT Unmethylated Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most common high-grade intracranial tumor in adults. It is characterized by uncontrolled proliferation, diffuse infiltration due to high invasive and migratory capacities, as well as intense resistance to chemo- and radiotherapy. With a five-year survival of less than 3% and an average survival rate of 12 months after diagnosis, GBM has become a focus of current research to urgently develop new therapeutic approaches in order to prolong survival of GBM patients. The methylation status of the promoter region of the O⁶-methylguanine–DNA methyltransferase (MGMT) is nowadays routinely analyzed since a methylated promoter region is beneficial for an effective response to temozolomide-based chemotherapy. Furthermore, several miRNAs were identified regulating MGMT expression, apart from promoter methylation, by degrading MGMT mRNA before protein translation. These miRNAs could be a promising innovative treatment approach to enhance Temozolomide (TMZ) sensitivity in MGMT unmethylated patients and to increase progression-free survival as well as long-term survival. In this review, the relevant miRNAs are systematically reviewed.

Recent Trends of microRNA Significance in Pediatric Population Glioblastoma and Current Knowledge of Micro RNA Function in Glioblastoma Multiforme

Central nervous system tumors are a significant problem for modern medicine because of their location. The explanation of the importance of microRNA (miRNA) in the development of cancerous changes plays an important role in this respect. The first papers describing the presence of miRNA were published in the 1990s. The role of miRNA has been pointed out in many medical conditions such as kidney disease, diabetes, neurodegenerative disorder, arthritis and cancer. There are several miRNAs responsible for invasiveness, apoptosis, resistance to treatment, angiogenesis, proliferation and immunology, and many others. The research conducted in recent years analyzing this group of tumors has shown the important role of miRNA in the course of gliomagenesis. These particles seem to participate in many stages of the development of cancer processes, such as proliferation, angiogenesis, regulation of apoptosis or cell resistance to cytostatics.

Identification of biomarkers for the transition from low-grade glioma to secondary glioblastoma by an integrated bioinformatic analysis

Secondary glioblastoma (sGBM) is a type of glioblastoma multiforme that evolves from low-grade glioma (LGG). However, the mechanism of this transition still remains poorly understood. In this study, we used weighted gene co-expression network analysis (WGCNA) on the gene expression profiles of glioma samples from the Chinese Glioma Genome Atlas (CGGA) database to identify key genetic module related to distinguish histological characteristics. Here, the brown module was highly correlated with histological characteristics and was selected as the hub module. By applying functional annotation analysis, we found that biological processes related to the cell-cycle and DNA-replication were enriched in the genes of the brown module. After constructing a protein-protein interaction (PPI) network, validation of differential gene expression, and survival analyses, we ultimately identified five hub genes: CCNB2 (Cyclin B2), KIF2C (Kinesin Family Member 2C), CDC20 (Cell Division Cycle 20), TPX2 (TPX2 Microtubule Nucleation Factor), and PLK1 (Polo Like Kinase 1). In addition, a computational risk model was developed for predicting the clinical outcomes of sGBM patients by combining gene expression levels. This gene signature was demonstrated to be an independent predictor of survival by univariate and multivariable Cox regression analysis. Finally, we used the Genomics of Drug Sensitivity in Cancer (GDSC) database to predict the responses of sGBM patients to routine chemotherapeutic drugs. Patients from the high-risk group were more sensitive to common chemotherapies during clinical treatment. Our findings based on comprehensive analyses might advance the understanding of sGBM transition and aid the development of novel biomarkers for diagnosing and predicting the survival of sGBM patients.

SYT16 is a prognostic biomarker and correlated with immune infiltrates in glioma: A study based on TCGA data

BACKGROUND

Glioma is the most lethal primary brain tumor. Lower-grade glioma (LGG) is the crucial pathological type of Glioma. Immune-infiltration of the tumor microenvironment positively associated with overall survival in LGG. SYT16 is a gene has not been reported in cancer. We assess the role of SYT16 in LGG, via the publicly available TCGA database.

METHODS

Gene Expression Profiling Interactive Analysis (GEPIA) was used to analyze the expression of SYT16 in LGG. We evaluated the influence of SYT16 on survival of LGG patients by survival module. Then, datasets of LGG were downloaded from TCGA. The correlations between the clinical information and SYT16 expression were analyzed using logistic regression. Univariable survival and Multivariate Cox analysis was used to compare several clinical characteristics with survival. we also explore the correlation between SYT16 and cancer immune infiltrates using CIBERSORT and correlation module of GEPIA. Gene set enrichment analysis (GSEA) was performed using the TCGA dataset. In addition, we use TIMER to explore the collection of SYT16 Expression and Immune Infiltration Level in LGG and to explore cumulative survival in LGG.

RESULTS

The univariate analysis using logistic regression, indicated that increased SYT16 expression significantly correlated with the tumor grade. Moreover, multivariate analysis revealed that the up-regulated SYT16 expression is an independent prognostic factor for good prognosis. Specifically, SYT16 expression level has significant negative correlations with infiltrating levels of B cell, CD4+ T cells, Macrophages, Neutrophils and DCs in LGG. In addition, GSEA identified ingle organism behavior, gated channel activity, cognition, transporter complex and ligand gated channel activity  in Gene Ontology (GO) were differentially enriched in the high SYT16 expression phenotype pathway. Neuroactive ligand receptor interaction, calcium signaling pathway, long term potentiation, type II diabetes mellitus and long term depression were identified as differentially enriched  pathway in Kyoto Encyclopedia of Genes and Genomes (KEGG).

CONCLUSION

SYT16 is a Prognostic Biomarker and Correlated with Immune Infiltrates in LGG.

Glioblastoma: Pathogenesis and Current Status of Chemotherapy and Other Novel Treatments

Glioblastoma is one of the most common and detrimental forms of solid brain tumor, with over 10,000 new cases reported every year in the United States. Despite aggressive multimodal treatment approaches, the overall survival period is reported to be less than 15 months after diagnosis. A widely used approach for the treatment of glioblastoma is surgical removal of the tumor, followed by radiotherapy and chemotherapy. While there are several drugs available that are approved by the Food and Drug Administration (FDA), significant efforts have been made in recent years to develop new chemotherapeutic agents for the treatment of glioblastoma. This review describes the molecular targets and pathogenesis as well as the current progress in chemotherapeutic development and other novel therapies in the clinical setting for the treatment of glioblastoma.

Remarkable response of a patient with secondary glioblastoma to a histone deacetylase inhibitor

Secondary glioblastoma is a rare brain tumor characterized by a mutation in isocitrate dehydrogenase, which is reported to lead to epigenetic modification. Patients with secondary glioblastoma experience poor survival and quality-of-life outcomes due to the disease’s aggressiveness and a lack of targeted therapies. In this report, a patient with a secondary glioblastoma was treated with a histone deacetylase inhibitor, an epigenetic drug with potent anti-inflammatory properties, in addition to the standard regimen. The patient showed very favorable survival and quality-of-life measures, and a restoration of several neuro-metabolites as measured by spectroscopic magnetic resonance imaging.

A comprehensive overview on the molecular biology of human glioma: what the clinician needs to know

The molecular biology of human glioma is a complex and fast-growing field in which basic research needs to meet clinical expectations in terms of anti-tumor efficacy. Although much effort is being done in molecular biology research, significant contribution to the quality of life and overall survival still lacks. The vastness of molecular biology literature makes it virtually impossible for clinicians to keep up to date in the field. This paper reviews some practical concepts regarding glioma tumorigenesis from the clinician's perspective. Five main aspects are discussed: major intracellular signaling pathways involved in glioma formation; genomic, epigenetic and transcriptomic relevant features of glioma; the prognostic and predictive values of molecular markers according to the new WHO classification of glial tumors; the importance of molecular and cellular heterogeneity in glioblastoma, responsible for its therapy resistance; and the interaction between glioma and the immune system, in view of the novel and promising targeted therapies.

The therapeutic potential of Aurora kinases targeting in glioblastoma: from preclinical research to translational oncology

Glioblastoma is the most common aggressive primary brain tumor. Standard care includes maximal safe surgical resection, radiation, and chemotherapy with temozolomide. However, the impact of this therapeutic approach on patient survival is disappointing and poor outcomes are frequently observed. Therefore, new therapeutic targets are needed to treat this potentially deadly tumor. Aurora kinases are one of today's most sought-after classes of therapeutic targets to glioblastoma therapy. They are a family of proteins composed of three members: Aurora-A, Aurora-B, and Aurora-C that play different roles in the cell division through regulation of chromosome segregation. Deregulation of these genes has been reported in glioblastoma and a progressive number of studies have shown that inhibition of these proteins could be a promising strategy for the treatment of this tumor. This review discusses the preclinical and early clinical findings on the potential use of the Aurora kinases as new targets for the treatment of glioblastoma. KEY MESSAGES: GBM is a very aggressive tumor with limited therapeutic options. Aurora kinases are a family of serine/threonine kinases implicated in GBM pathology. Aurora kinases are critical for glioblastoma cell growth, apoptosis, and chemoresistance. Inhibition of Aurora kinases has a synergistic or sensitizing effect with chemotherapy drugs, radiotherapy, or with other targeted molecules in GBM. Several Aurora kinase inhibitors are currently in clinical trials.

Tumor Copy Number Deconvolution Integrating Bulk and Single-Cell Sequencing Data

Characterizing intratumor heterogeneity (ITH) is crucial to understanding cancer development, but it is hampered by limits of available data sources. Bulk DNA sequencing is the most common technology to assess ITH, but involves the analysis of a mixture of many genetically distinct cells in each sample, which must then be computationally deconvolved. Single-cell sequencing is a promising alternative, but its limitations-for example, high noise, difficulty scaling to large populations, technical artifacts, and large data sets-have so far made it impractical for studying cohorts of sufficient size to identify statistically robust features of tumor evolution. We have developed strategies for deconvolution and tumor phylogenetics combining limited amounts of bulk and single-cell data to gain some advantages of single-cell resolution with much lower cost, with specific focus on deconvolving genomic copy number data. We developed a mixed membership model for clonal deconvolution via non-negative matrix factorization balancing deconvolution quality with similarity to single-cell samples via an associated efficient coordinate descent algorithm. We then improve on that algorithm by integrating deconvolution with clonal phylogeny inference, using a mixed integer linear programming model to incorporate a minimum evolution phylogenetic tree cost in the problem objective. We demonstrate the effectiveness of these methods on semisimulated data of known ground truth, showing improved deconvolution accuracy relative to bulk data alone.

Long Noncoding RNA LINC00467 Promotes Glioma Progression through Inhibiting P53 Expression via Binding to DNMT1

Purpose: This study aimed to investigate whether long noncoding RNA (lncRNA) LINC00467 could regulate proliferative and invasive abilities of glioma cells via p53 and DNA methyltransferase 1 (DNMT1), so as to participate in the occurrence and progression of glioma. Methods: LINC00467 expression in glioma was analyzed by GEPIA database and LINC00467 expression in glioma cell lines was detected by qRT-PCR. The regulatory effects of LINC00467 and p53 on proliferative, invasive capacities and cell cycle were conducted by CCK-8 and EdU assays, transwell assay and flow cytometry, respectively. The binding conditions between LINC00467, DNMT1 and p53 were determined by RNA immunoprecipitation (RIP) and Chromatin immunoprecipitation (ChIP) assays. Western blot was conducted to determine whether LINC00467 could regulate p53 in glioma cells. Finally, rescue experiments were carried out to evaluate whether LINC00467 regulates proliferative and invasive abilities of glioma cells through p53. Results: The expression of LINC00467 was significantly up-regulated in tumor samples than that in normal samples, which was not correlated with patient survival time. Besides, expression of LINC00467 was higher in glioma cells than that of negative control cells. Upregulation of LINC00467 promoted proliferative and invasive abilities, and accelerated cell cycle in G0/G1 phase of U87 and LN229 cells. The results of RIP and ChIP assays demonstrated that LINC00467 could bind to DNMT1 and inhibit p53 expression. Overexpression of p53 partially reversed the enhancement of LINC00467 on proliferative and invasive abilities of glioma cells. Conclusion: These results indicated that high expression of LINC00467 could promote proliferative and invasive abilities of glioma cells through targeting inhibition of p53 expression by binding to DNMT1.

Copy number assessment in the genomic analysis of CNS neoplasia: An evidence-based review from the cancer genomics consortium (CGC) working group on primary CNS tumors

The period from the 1990s to the 2010s has witnessed a burgeoning sea change in the practice of surgical neuropathology due to the incorporation of genomic data into the assessment of a range of central nervous system (CNS) neoplasms. This change has since matured into the adoption of genomic information into the definition of several World Health Organization (WHO)-established diagnostic entities. The data needed to accomplish the modern diagnosis of CNS neoplasia includes DNA copy number aberrations that may be assessed through a variety of mechanisms. Through a review of the relevant literature and professional practice guidelines, here we provide a condensed and scored overview of the most critical DNA copy number aberrations to assess for a selection of primary CNS neoplasms.

Additional Diagnostic Value of Unenhanced Computed Tomography plus Diffusion-Weighted Imaging Combined with Routine Magnetic Resonance Imaging Findings of Early-Stage Gliblastoma

PURPOSE

This study was performed to determine whether diffusion-weighted imaging (DWI) plus unenhanced computed tomography (CT) of the brain increases the diagnostic value of routine magnetic resonance (MR) imaging findings of early-stage glioblastoma.

METHODS

Postcontrast MR images of eight unenhanced lesions that had been pathologically diagnosed as glioblastoma were retrospectively examined. The location, margin, signal intensity, and attenuation on MR imaging and CT were assessed.

RESULTS

On MR imaging, all lesions were ill-defined, small, and isointense to hypointense on T1-weighted images and hyperintense on T2-weighted images. Four patients had perilesional edema. In seven patients, DWI showed an inhomogeneous hyperintense lesion (n = 1) or isointense lesion with a hyperintense region (n = 1) or isointense lesion with a hyperintense region (n = 1) or isointense lesion with a hyperintense region (n = 1) or isointense lesion with a hyperintense region (n = 1) or isointense lesion with a hyperintense region (n = 1) or isointense lesion with a hyperintense region (n = 1) or isointense lesion with a hyperintense region (n = 1) or isointense lesion with a hyperintense region (n = 1) or isointense lesion with a hyperintense region (.

CONCLUSIONS

MR imaging was the most sensitive imaging method for depicting early-stage glioblastoma. The CT finding of a hyperattenuated or isoattenuated region combined with the DWI finding of the same region containing an inhomogeneous hyperintense lesion or isointense lesion with a hyperintense region may be a specific diagnostic sign for early-stage glioblastoma. DWI plus unenhanced CT added diagnostic value to the routine MR imaging findings of early-stage glioblastoma.

Retrospective and Randomized Analysis of Influence and Correlation of Clinical and Molecular Prognostic Factors in a Mono-Operative Series of 122 Patients with Glioblastoma Treated with STR or GTR

Glioblastoma is a solid, infiltrating, and the most frequent highly malignant primary brain tumor. Our aim was to find the correlation between sex, age, preoperative Karnofsky performance status (KPS), presenting with seizures, and extent of resection (EOR) with overall survival (OS), progression-free survival (PFS), and postoperative KPS, along with the prognostic value of IDH1, MGMT, ATRX, EGFR, and TP53 genes mutations and of Ki67 through the analysis of a single-operator series in order to avoid the biases of a multi-operator series, such as the lack of homogeneity in surgical and adjuvant nonsurgical treatments. A randomized retrospective analysis of 122 patients treated by a single first operator at Sapienza University of Rome was carried out. After surgery, patients followed standard Stupp protocol treatment. Exclusion criteria were: (1) patients with primary brainstem and spinal cord gliomas and (2) patients who underwent partial resections (resection < 90%) or a biopsy exclusively for diagnostic purposes. Statistical analysis with a simultaneous regression model was carried out through the use of SPSS 25^® (IBM). Results showed statistically significant survival increase in four groups: (1) patients treated with gross total resection (GTR) (p < 0.030); (2) patients with mutation of IDH1 (p < 0.0161); (3) patients with methylated MGMT promoter (p < 0.005); (4) patients without EGFR amplification or EGFRvIII mutation (p < 0.035). Higher but not statistically significant survival rates were also observed in: patients <75 years, patients presenting with seizures at diagnosis, patients affected by lesions in noneloquent areas, as well as in patients with ATRX gene mutation and Ki-67 < 10%.

Long noncoding RNA MALAT1 may be a prognostic biomarker in IDH1/2 wild-type primary glioblastomas

Primary glioblastoma (GB) is the most aggressive type of brain tumors. While mutations in isocitrate dehydrogenase (IDH) genes are frequent in secondary GBs and correlate with a better prognosis, most primary GBs are IDH wild-type. Recent studies have shown that the long noncoding RNA metastasis associated lung adenocarcinoma transcript-1 (MALAT1) is associated with aggressive tumor phenotypes in different cancers. Our aim was to clarify the prognostic significance of MALAT1 in IDH1/2 wild-type primary GB tumors. We analyzed IDH1/2 mutation status in 75 patients with primary GB by DNA sequencing. The expression of MALAT1 was detected in the 75 primary GB tissues and 5 normal brain tissues using reverse transcription quantitative PCR (RT-qPCR). The associations between MALAT1 expression, IDH1/2 mutation status, and clinicopathological variables of patients were determined. IDH1 (R132H) mutation was observed in 5/75 primary GBs. IDH2 (R172H) mutation was not detected in any of our cases. MALAT1 expression was significantly upregulated in primary GB vs. normal brain tissues (p = 0.025). Increased MALAT1 expression in IDH1/2 wild-type primary GBs correlated with patient age and tumor localization (p = 0.032 and p = 0.025, respectively). A multivariate analysis showed that high MALAT1 expression was an unfavorable prognostic factor for overall survival (p = 0.034) in IDH1/2 wild-type primary GBs. High MALAT1 expression may have a prognostic role in primary GBs independent of IDH mutations.

Autocrine CXCL8-dependent invasiveness triggers modulation of actin cytoskeletal network and cell dynamics

Glioblastoma (GB) is the most representative form of primary malignant brain tumour. Several studies indicated a pleiotropic role of CXCL8 in cancer due to its ability to modulate the tumour microenvironment, growth and aggressiveness of tumour cell. Previous studies indicated that CXCL8 by its receptors (CXCR1 and CXCR2) induced activation of the PI3K/p-Akt pathway, a crucial event in the regulation of cytoskeleton rearrangement and cell mobilization. Human GB primary cell culture and U-87MG cell line were used to study the effects of CXCR1 and CXCR2 blockage, by a dual allosteric antagonist, on cell migration and cytoskeletal dynamics. The data obtained point towards a specific effect of autocrine CXCL8 signalling on GB cell invasiveness by the activation of pathways involved in cell migration and cytoskeletal dynamics, such as PI3K/p-Akt/p-FAK, p-cortactin, RhoA, Cdc42, Acetylated α-tubulin and MMP2. All the data obtained support the concept that autocrine CXCL8 signalling plays a key role in the activation of an aggressive phenotype in primary glioblastoma cells and U-87MG cell line. These results provide new insights about the potential of a pharmacological approach targeting CXCR1/CXCR2 pathways to decrease migration and invasion of GB cells in the brain parenchyma, one of the principal mechanisms of recurrence.

Upregulation of DEAD box helicase 5 and 17 are correlated with the progression and poor prognosis in gliomas

Recent researches indicated Ddx5 and Ddx17 play crucial roles in tumorigenesis. However, the study of Ddx5 and Ddx17 in glioma remains a little. Our study investigated their expression in glioma and evaluated its association with clinical factors and prognostic significance. The expression of Ddx5 and Ddx17 were both upregulated in glioma tissues compared to normal brain tissues, and a significant positive correlation between Ddx5 and Ddx17 expression was identified by statistical analysis. Immunohistochemical staining verified the expression of Ddx5 and Ddx17 in peritumoral zone was lower than that in core zone but higher than normal brain tissues. Moreover, the increased expression of Ddx5 and Ddx17 was markedly correlated with WHO Grade and histological type, and high Ddx5 and Ddx17 were found to be significantly associated with the worse overall survival of glioma patients. In additional, higher expression of both Ddx5 and Ddx17 predicted shorter clinical survival time for high-grade glioma patients with radiotherapy or with chemotherapy. In conclusion, overexpressed Ddx5 and Ddx17 are involved in the clinical progression and poor prognosis of glioma patients, suggesting that their upregulation can be used as a reliable clinical predictor for tumor diagnosis and to predict survival in patients with glioma.

Potential implications of hydrogen peroxide in the pathogenesis and therapeutic strategies of gliomas

Glioma is the most common type of primary brain tumor, and it has a high mortality rate. Currently, there are only a few therapeutic approaches for gliomas, and their effects are unsatisfactory. Therefore, uncovering the pathogenesis and exploring more therapeutic strategies for the treatment of gliomas are urgently needed to overcome the ongoing challenges. Cellular redox imbalance has been shown to be associated with the initiation and progression of gliomas. Among reactive oxygen species (ROS), hydrogen peroxide (H₂O₂) is considered the most suitable for redox signaling and is a potential candidate as a key molecule that determines the fate of cancer cells. In this review, we discuss the potential cellular and molecular roles of H₂O₂ in gliomagenesis and explore the potential implications of H₂O₂ in radiotherapy and chemotherapy and in the ongoing challenges of current glioma treatment. Moreover, we evaluate H₂O₂ as a potential redox sensor and potential driver molecule of nanocatalytic therapeutic strategies for glioma treatment.

Loss of cytoskeleton protein ADD3 promotes tumor growth and angiogenesis in glioblastoma multiforme

Adducin 3 (ADD3) is a crucial assembly factor in the actin cytoskeleton and has been found to be aberrantly expressed in various cancers, including glioblastoma multiforme (GBM). It has previously been studied in array-based studies with controversial findings as to its functional role in glioma. In microarray analyses of 452 glioma specimens, we found significant downregulation of ADD3 in GBM, but not in less malignant gliomas, compared to normal brain tissue, which suggests that its downregulation might underlie critical events during malignant progression. We also found that ADD3 was functionally dependent on cell-matrix interaction. In our in vivo study, the proliferative and angiogenic capacity of ADD3-depleted GBM cells was promoted, possibly through PCNA, while p53 and p21 expression was suppressed, and pro-angiogenic signals were induced through VEGF-VEGFR-2-mediated activation in endothelial cells. With correlative in vitro, in vivo, and clinical data, we provide compelling evidence on the putative tumor-suppressive role of ADD3 in modulating GBM growth and angiogenesis. As a preclinical study, our research offers a better understanding of the pathogenesis of glioma malignant progression for the benefit of future investigations.

Open Data for Differential Network Analysis in Glioma

The complexity of cancer diseases demands bioinformatic techniques and translational research based on big data and personalized medicine. Open data enables researchers to accelerate cancer studies, save resources and foster collaboration. Several tools and programming approaches are available for analyzing data, including annotation, clustering, comparison and extrapolation, merging, enrichment, functional association and statistics. We exploit openly available data via cancer gene expression analysis, we apply refinement as well as enrichment analysis via gene ontology and conclude with graph-based visualization of involved protein interaction networks as a basis for signaling. The different databases allowed for the construction of huge networks or specified ones consisting of high-confidence interactions only. Several genes associated to glioma were isolated via a network analysis from top hub nodes as well as from an outlier analysis. The latter approach highlights a mitogen-activated protein kinase next to a member of histondeacetylases and a protein phosphatase as genes uncommonly associated with glioma. Cluster analysis from top hub nodes lists several identified glioma-associated gene products to function within protein complexes, including epidermal growth factors as well as cell cycle proteins or RAS proto-oncogenes. By using selected exemplary tools and open-access resources for cancer research and differential network analysis, we highlight disturbed signaling components in brain cancer subtypes of glioma.

Raman and FTIR spectroscopy in determining the chemical changes in healthy brain tissues and glioblastoma tumor tissues

Glioblastoma, also called glioblastoma multiforme (GBM), is a particularly malignant form of primary brain tumor. This cancer accounts for 12-15% of all brain tumors. Despite the advances in neurosurgery, radio and chemotherapy the average survival rate is only 12.1-16.6 months. This is due not only to the late diagnosis of the disease, but also to ineffective treatment methods which result from the still low knowledge about the causes of glioblastoma development. Therefore, it is very important to look for new diagnostic methods of detection of the smallest features of cancer. Raman and infrared spectroscopy (FTIR) can be such methods. In this paper we discuss the chemical composition of sample glioblastoma brain tissues and marginal brain tissues using these two spectroscopy methods. Raman and FTIR spectra of cancer brain tissues showed that the highest differences in the chemical composition, compared to the control brain tissue, occur in the areas corresponding to lipids, collagen and proteins. Moreover, Raman spectroscopy also showed significant changes in the cancer tissues in the phosphatidylcholine and sphingomyelin. Interestingly, FTIR spectra after Kramers-Kronig transformations showed signals only for three peaks which corresponded to the vibrations of lipid function groups. Adjustment of the Lorenz function for these three peaks showed that only in the case of cancerous tissues the number of matching lines is different, compared to the control and marginal tissues. Therefore, we assume that lipids could be a spectroscopic marker for brain tumor. Furthermore, principal component analysis (PCA) showed that chemical changes seen between cancer and control tissues are significant and it is possible to differentiate the infected tissue from the healthy one. Interestingly, the PCA analysis also showed that adjacent brain tissues have different chemical composition than the control tissues.

Oncogenic Gain of Function in Glioblastoma Is Linked to Mutant p53 Amyloid Oligomers

Tumor-associated p53 mutations endow cells with malignant phenotypes, including chemoresistance. Amyloid-like oligomers of mutant p53 transform this tumor suppressor into an oncogene. However, the composition and distribution of mutant p53 oligomers are unknown and the mechanism involved in the conversion is sparse. Here, we report accumulation of a p53 mutant within amyloid-like p53 oligomers in glioblastoma-derived cells presenting a chemoresistant gain-of-function phenotype. Statistical analysis from fluorescence fluctuation spectroscopy, pressure-induced measurements, and thioflavin T kinetics demonstrates the distribution of oligomers larger than the active tetrameric form of p53 in the nuclei of living cells and the destabilization of native-drifted p53 species that become amyloid. Collectively, these results provide insights into the role of amyloid-like mutant p53 oligomers in the chemoresistance phenotype of malignant and invasive brain tumors and shed light on therapeutic options to avert cancer.

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Amyloid oligomers transform p53 tumor suppressor into an oncogene

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Amyloid-like mutant p53 oligomers occur in chemoresistant glioblastoma cells

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p53 oligomer larger than tetramers is detected in the nuclei of living cells

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Gain-of-function p53 phenotypes is attributed to p53 amyloid oligomers