Oncolytic viruses as a promising therapeutic strategy against the detrimental health impacts of air pollution: The case of glioblastoma multiforme

Human livelihood highly depends on applying different sources of energy whose utilization is associated with air pollution. On the other hand, air pollution may be associated with glioblastoma multiforme (GBM) development. Unlike other environmental causes of cancer (e.g., irradiation), air pollution cannot efficiently be controlled by geographical borders, regulations, and policies. The unavoidable exposure to air pollution can modify cancer incidence and mortality. GBM treatment with chemotherapy or even its surgical removal has proven insufficient (100% recurrence rate; patient's survival mean of 15 months; 90% fatality within five years) due to glioma infiltrative and migratory capacities. Given the barrage of attention and research investments currently plowed into next-generation cancer therapy, oncolytic viruses are perhaps the most vigorously pursued. Provision of an insight into the current state of the research and future direction is essential for stimulating new ideas with the potentials of filling research gaps. This review manuscript aims to overview types of brain cancer, their burden, and different causative agents. It also describes why air pollution is becoming a concerning factor. The different opinions on the association of air pollution with brain cancer are reviewed. It tries to address the significant controversy in this field by hypothesizing the air-pollution-brain-cancer association via inflammation and atopic conditions. The last section of this review deals with the oncolytic viruses, which have been used in, or are still under clinical trials for GBM treatment. Engineered adenoviruses (i.e., DNX-2401, DNX-2440, CRAd8-S-pk7 loaded Neural stem cells), herpes simplex virus type 1 (i.e., HSV-1 C134, HSV-1 rQNestin34.5v.2, HSV-1 G207, HSV-1 M032), measles virus (i.e., MV-CEA), parvovirus (i.e., ParvOryx), poliovirus (i.e., Poliovirus PVSRIPO), reovirus (i.e., pelareorep), moloney murine leukemia virus (i.e., Toca 511 vector), and vaccinia virus (i.e., vaccinia virus TG6002) as possible life-changing alleviations for GBM have been discussed. To the best of our knowledge, this review is the first review that comprehensively discusses both (i) the negative/positive association of air pollution with GBM; and (ii) the application of oncolytic viruses for GBM, including the most recent advances and clinical trials. It is also the first review that addresses the controversies over air pollution and brain cancer association. We believe that the article will significantly appeal to a broad readership of virologists, oncologists, neurologists, environmentalists, and those who work in the field of (bio)energy. Policymakers may also use it to establish better health policies and regulations about air pollution and (bio)fuels exploration, production, and consumption.

HIF2α Upregulates the Migration Factor ODZ1 under Hypoxia in Glioblastoma Stem Cells

Background: Glioblastoma (GBM) remains a major clinical challenge due to its invasive capacity, resistance to treatment, and recurrence. We have previously shown that ODZ1 contributes to glioblastoma invasion and that ODZ1 mRNA levels can be upregulated by epigenetic mechanisms in response to hypoxia. Herein, we have further studied the transcriptional regulation of ODZ1 in GBM stem cells (GSCs) under hypoxic conditions and analyzed whether HIF2α has any role in this regulation. Methods: We performed the experiments in three primary GSC cell lines established from tumor specimens. GSCs were cultured under hypoxia, treated with HIF regulators (DMOG, chetomin), or transfected with specific siRNAs, and the expression levels of ODZ1 and HIF2α were analyzed. In addition, the response of the ODZ1 promoter cloned into a luciferase reporter plasmid to the activation of HIF was also studied. Results: The upregulation of both mRNA and protein levels of HIF2α under hypoxia conditions correlated with the expression of ODZ1 mRNA. Moreover, the knockdown of HIF2α by siRNAs downregulated the expression of ODZ1. We found, in the ODZ1 promoter, a HIF consensus binding site (GCGTG) 1358 bp from the transcription start site (TSS) and a HIF-like site (CCGTG) 826 bp from the TSS. Luciferase assays revealed that the stabilization of HIF by DMOG resulted in the increased activity of the ODZ1 promoter. Conclusions: Our data indicate that the HIF2α-mediated upregulation of ODZ1 helps strengthen the transcriptional control of this migration factor under hypoxia in glioblastoma stem cells. The discovery of this novel transcriptional pathway identifies new targets to develop strategies that may avoid GBM tumor invasion and recurrence.

Bisdemethoxycurcumin Induces Cell Apoptosis and Inhibits Human Brain Glioblastoma GBM 8401/Luc2 Cell Xenograft Tumor in Subcutaneous Nude Mice In Vivo

Bisdemethoxycurcumin (BDMC) has biological activities, including anticancer effects in vitro; however, its anticancer effects in human glioblastoma (GBM) cells have not been examined yet. This study aimed to evaluate the tumor inhibitory effect and molecular mechanism of BDMC on human GBM 8401/luc2 cells in vitro and in vivo. In vitro studies have shown that BDMC significantly reduced cell viability and induced cell apoptosis in GBM 8401/luc2 cells. Furthermore, BDMC induced apoptosis via inhibited Bcl-2 (anti-apoptotic protein) and increased Bax (pro-apoptotic proteins) and cytochrome c release in GBM 8401/luc2 cells in vitro. Then, twelve BALB/c-nude mice were xenografted with human glioblastoma GBM 8401/luc2 cancer cells subcutaneously, and the xenograft nude mice were treated without and with BDMC (30 and 60 mg/kg of BDMC treatment) every 3 days. GBM 8401/luc2 cell xenografts experiment showed that the growth of the tumors was significantly suppressed by BDMC administration at both doses based on the reduction of tumor size and weights. BDMC did not change the body weight and the H&E histopathology analysis of liver samples, indicating that BDMC did not induce systemic toxicity. Meanwhile, treatment with BDMC up-regulated the expressions of BAX and cleaved caspase-3, while it down-regulated the protein expressions of Bcl-2 and XIAP in the tumor tissues compared with the control group. This study has demonstrated that BDMC presents potent anticancer activity on the human glioblastoma GBM 8401/luc2 cell xenograft model by inducing apoptosis and inhibiting tumor cell proliferation and shows the potential for further development to the anti-GBM cancer drug.

Targeting DYRK1A/B kinases to modulate p21-cyclin D1-p27 signalling and induce anti-tumour activity in a model of human glioblastoma

The dual-specificity tyrosine-regulated kinases DYRK1A and DYRK1B play a key role in controlling the quiescence-proliferation switch in cancer cells. Serum reduction of U87MG 2D cultures or multi-cellular tumour spheroids induced a quiescent like state characterized by increased DYRK1B and p27, and decreased pRb and cyclin D1. VER-239353 is a potent, selective inhibitor of the DYRK1A and DYRK1B kinases identified through fragment and structure-guided drug discovery. Inhibition of DYRK1A/B by VER-239353 in quiescent U87MG cells increased pRb, DYRK1B and cyclin D1 but also increased the cell cycle inhibitors p21 and p27. This resulted in exit from G0 but subsequent arrest in G1. DYRK1A/B inhibition reduced the proliferation of U87MG cells in 2D and 3D culture with greater effects observed under reduced serum conditions. Paradoxically, the induced re-expression of cell cycle proteins by DYRK1A/B inhibition further inhibited cell proliferation. Cell growth arrest induced in quiescent cells by DYRK1A/B inhibition was reversible through the addition of growth-promoting factors. DYRK inhibition-induced DNA damage and synergized with a CHK1 inhibitor in the U87MG spheroids. In vivo, DYRK1A/B inhibition-induced tumour stasis in a U87MG tumour xenograft model. These results suggest that further evaluation of VER-239353 as a treatment for glioblastoma is therefore warranted.

Evaluation of Haptoglobin and Its Proteoforms as Glioblastoma Markers

Haptoglobin (Hp) is a blood plasma glycoprotein that plays a critical role in tissue protection and the prevention of oxidative damage. Haptoglobin is an acute-phase protein, its concentration in plasma changes in pathology, and the test for its concentration is part of normal clinical practice. Haptoglobin is a conservative protein and is the subject of research as a potential biomarker of many diseases, including malignant neoplasms. The Human Hp gene is polymorphic and controls the synthesis of three major phenotypes-homozygous Hp1-1 and Hp2-2, and heterozygous Hp2-1, determined by a combination of allelic variants that are inherited. Numerous studies indicate that the phenotype of haptoglobin can be used to judge the individual's predisposition to various diseases. In addition, Hp undergoes various post-translational modifications (PTMs). Glioblastoma multiform (GBM) is the most malignant primary brain tumor. In our study, we have analyzed the state of Hp proteoforms in plasma and cells using 1D (SDS-PAGE) and 2D electrophoresis (2DE) with the following mass spectrometry (LC ES-MS/MS) or Western blotting. We found that the levels of α2- and β-chain proteoforms are up-regulated in the plasma of GBM patients. An unprocessed form of Hp2-2 (PreHp2-2, zonulin) with unusual biophysical parameters (pI/Mw) was also detected in the plasma of GBM patients and glioblastoma cells. Altogether, this data shows the possibility to use proteoforms of haptoglobin as a potential GBM-specific plasma biomarker.

Tumor Vessels Fuel the Fire in Glioblastoma

Glioblastoma, a subset of aggressive brain tumors, deploy several means to increase blood vessel supply dedicated to the tumor mass. This includes typical program borrowed from embryonic development, such as vasculogenesis and sprouting angiogenesis, as well as unconventional processes, including co-option, vascular mimicry, and transdifferentiation, in which tumor cells are pro-actively engaged. However, these neo-generated vascular networks are morphologically and functionally abnormal, suggesting that the vascularization processes are rather inefficient in the tumor ecosystem. In this review, we reiterate the specificities of each neovascularization modality in glioblastoma, and, how they can be hampered mechanistically in the perspective of anti-cancer therapies.

Single-cell characterization of macrophages in glioblastoma reveals MARCO as a mesenchymal pro-tumor marker

BACKGROUND

Macrophages are the most common infiltrating immune cells in gliomas and play a wide variety of pro-tumor and anti-tumor roles. However, the different subpopulations of macrophages and their effects on the tumor microenvironment remain poorly understood.

METHODS

We combined new and previously published single-cell RNA-seq data from 98,015 single cells from a total of 66 gliomas to profile 19,331 individual macrophages.

RESULTS

Unsupervised clustering revealed a pro-tumor subpopulation of bone marrow-derived macrophages characterized by the scavenger receptor MARCO, which is almost exclusively found in IDH1-wild-type glioblastomas. Previous studies have implicated MARCO as an unfavorable marker in melanoma and non-small cell lung cancer; here, we find that bulk MARCO expression is associated with worse prognosis and mesenchymal subtype. Furthermore, MARCO expression is significantly altered over the course of treatment with anti-PD1 checkpoint inhibitors in a response-dependent manner, which we validate with immunofluorescence imaging.

CONCLUSIONS

These findings illustrate a novel macrophage subpopulation that drives tumor progression in glioblastomas and suggest potential therapeutic targets to prevent their recruitment.

Radiation induced glioma in a sexagenarian: A case report

INTRODUCTION

Radiation induced gliomas often occurs after radiation therapy for other brain tumors. Medulloblastoma often occurs in children and its associated radiation-induced glioblastoma multiforme's (GBM) after radiotherapy often has a long latency period. Our case is very unique because the medulloblastoma was detected at an advance age and the latency period of radiation-induced GBM was relatively shorter.

PATIENTS CONCERNS

A 64-year-old male was first admitted at our hospital in March 2018 with dizziness, vomiting, and blurred vision.

DIAGNOSIS

Magnetic resonance imaging of brain revealed a lesion with local mixed density and mass enhancement in left cerebellar region. Histopathology established medulloblastoma (World Health Organization) grade 4 and a classic histological subtype after surgery.

INTERVENTION

Surgical resection followed by radiation therapy were the initial therapeutic modalities.

OUTCOMES

In April 2019, the patient was readmitted with dizziness and blurred vision. Magnetic resonance imaging showed the left cerebellar hemisphere bulky enhancement lesion. Again, a multimodal therapy comprising surgical resection, radiation therapy as well as chemotherapy was adapted after histopathology established GBM.

LESION

Radiotherapy for medulloblastoma patients at advance ages is a critical predisposing factor for the development of radiation-induced GBM in a very short period of time. We suggest that, radiotherapy as adjuvant therapy for medulloblastoma patients at advance ages should be chosen with extreme caution.

Regulation of Fibroblast Activation Protein by Transforming Growth Factor Beta-1 in Glioblastoma Microenvironment

The proline-specific serine protease fibroblast activation protein (FAP) can participate in the progression of malignant tumors and represents a potential diagnostic and therapeutic target. Recently, we demonstrated an increased expression of FAP in glioblastomas, particularly those of the mesenchymal subtype. Factors controlling FAP expression in glioblastomas are unknown, but evidence suggests that transforming growth factor beta (TGFbeta) can trigger mesenchymal changes in these tumors. Here, we investigated whether TGFbeta promotes FAP expression in transformed and stromal cells constituting the glioblastoma microenvironment. We found that both FAP and TGFbeta-1 are upregulated in glioblastomas and display a significant positive correlation. We detected TGFbeta-1 immunopositivity broadly in glioblastoma tissues, including tumor parenchyma regions in the immediate vicinity of FAP-immunopositive perivascular stromal cells. Wedemonstrate for the first time that TGFbeta-1 induces expression of FAP in non-stem glioma cells, pericytes, and glioblastoma-derived endothelial and FAP⁺ mesenchymal cells, but not in glioma stem-like cells. In glioma cells, this effect is mediated by the TGFbeta type I receptor and canonical Smad signaling and involves activation of FAP gene transcription. We further present evidence of FAP regulation by TGFbeta-1 secreted by glioma cells. Our results provide insight into the previously unrecognized regulation of FAP expression by autocrine and paracrine TGFbeta-1 signaling in a broad spectrum of cell types present in the glioblastoma microenvironment.

Radiation-induced glioblastoma of the conus medullaris from radiation treatment of cervical cancer

Radiation-induced spinal glioblastoma is an extremely rare disease with only four previously published reports in the literature. We report the fifth case, a 69-year-old woman who previously underwent treatment with brachytherapy for cervical cancer, and thereafter presented with neurologic deficits from a conus medullaris tumour. Biopsy and histopathology confirm glioblastoma, not otherwise specified. Treatment of spinal glioblastoma consists of surgery, either biopsy or excision and chemoradiation. However, results are still unsatisfactory and prognosis remains poor.

Chimeric Antigen Receptor T-Cell Therapy in Glioblastoma: Current and Future

Glioblastoma (GBM) is a highly aggressive glioma with an extremely poor prognosis after conventional treatment. Recent advances in immunotherapy offer hope for these patients with incurable GBM. Our present review aimed to provide an overview of immunotherapy for GBM, especially chimeric antigen receptor T-cell (CAR T) therapy. CAR T-cell immunotherapy, which involves the engineering of T cells to kill tumors by targeting cell surface-specific antigens, has been successful in eliminating B-cell leukemia by targeting CD19. IL-13Rα2, EGFRvIII, and HER2-targeted CAR T cells have shown significant clinical efficacy and safety in phase 1 or 2 clinical trials conducted in patients with GBM; these findings support the need for further studies to examine if this therapy can ultimately benefit this patient group. However, local physical barriers, high tumor heterogeneity, and antigen escape make the use of CAR T therapy, as a treatment for GBM, challenging. The potential directions for improving the efficacy of CAR T in GBM are to combine the existing traditional therapies and the construction of multi-target CAR T cells.

RBPJ contributes to the malignancy of glioblastoma and induction of proneural-mesenchymal transition via IL-6-STAT3 pathway

Notch signaling plays a pivotal role in many cancers, including glioblastoma (GBM). Recombination signal binding protein for immunoglobulin kappa J region (RBPJ) is a key transcription factor of the Notch signaling pathway. Here, we interrogated the function of RBPJ in GBM. Firstly, RBPJ expression of GBM samples was examined. Then, we knocked down RBPJ expression in 2 GBM cell lines (U251 and T98) and 4 glioblastoma (GBM) stem-like cell lines derived from surgical samples of GBM (KGS01, KGS07, KGS10 and KGS15) to investigate the effect on cell proliferation, invasion, stemness, and tumor formation ability. Expression of possible downstream targets of RBPJ was also assessed. RBPJ was overexpressed in the GBM samples, downregulation of RBPJ reduced cell proliferation and the invasion ability of U251 and T98 cells and cell proliferation ability and stemness of glioblastoma stem-like cells (GSC) lines. These were accompanied by reduced IL-6 expression, reduced activation of STAT3, and inhibited proneural-mesenchymal transition (PMT). Tumor formation and PMT were also impaired by RBPJ knockdown in vivo. In conclusion, RBPJ promotes cell proliferation, invasion, stemness, and tumor initiation ability in GBM cells through enhanced activation of IL-6-STAT3 pathway and PMT, inhibition of RBPJ may constitute a prospective treatment for GBM.

Novel Molecular Markers in Glioblastoma-Benefits of Liquid Biopsy

Glioblastoma is a primary Central Nervous System (CNS) malignancy with poor survival. Treatment options are scarce and despite the extremely heterogeneous nature of the disease, clinicians lack prognostic and predictive markers to characterize patients with different outcomes. Certain immunohistochemistry, FISH, or PCR-based molecular markers, including isocitrate dehydrogenase1/2 (IDH1/2) mutations, epidermal growth factor receptor variant III (EGFRvIII) mutation, vascular endothelial growth factor overexpression (VEGF) overexpression, or (O6-Methylguanine-DNA methyltransferase promoter) MGMT promoter methylation status, are well-described; however, their clinical usefulness and accuracy is limited, and tumor tissue samples are always necessary. Liquid biopsy is a developing field of diagnostics and patient follow up in multiple types of cancer. Fragments of circulating nucleic acids are collected in various forms from different bodily fluids, including serum, urine, or cerebrospinal fluid in order to measure the quality and quantity of these markers. Multiple types of nucleic acids can be analyzed using liquid biopsy. Circulating cell-free DNA, mitochondrial DNA, or the more stable long and small non-coding RNAs, circular RNAs, or microRNAs can be identified and measured by novel PCR and next-generation sequencing-based methods. These markers can be used to detect the previously described alterations in a minimally invasive method. These markers can be used to differentiate patients with poor or better prognosis, or to identify patients who do not respond to therapy. Liquid biopsy can be used to detect recurrent disease, often earlier than using imaging modalities. Liquid biopsy is a rapidly developing field, and similarly to other types of cancer, measuring circulating tumor-derived nucleic acids from biological fluid samples could be the future of differential diagnostics, patient stratification, and follow up in the future in glioblastoma as well.

The impact of autophagy during the development and survival of glioblastoma

Glioblastoma is the most common and aggressive adult brain tumour, with poor median survival and limited treatment options. Following surgical resection and chemotherapy, recurrence of the disease is inevitable. Genomic studies have identified key drivers of glioblastoma development, including amplifications of receptor tyrosine kinases, which drive tumour growth. To improve treatment, it is crucial to understand survival response processes in glioblastoma that fuel cell proliferation and promote resistance to treatment. One such process is autophagy, a catabolic pathway that delivers cellular components sequestered into vesicles for lysosomal degradation. Autophagy plays an important role in maintaining cellular homeostasis and is upregulated during stress conditions, such as limited nutrient and oxygen availability, and in response to anti-cancer therapy. Autophagy can also regulate pro-growth signalling and metabolic rewiring of cancer cells in order to support tumour growth. In this review, we will discuss our current understanding of how autophagy is implicated in glioblastoma development and survival. When appropriate, we will refer to findings derived from the role of autophagy in other cancer models and predict the outcome of manipulating autophagy during glioblastoma treatment.

The RNA-binding protein SERBP1 functions as a novel oncogenic factor in glioblastoma by bridging cancer metabolism and epigenetic regulation

BACKGROUND

RNA-binding proteins (RBPs) function as master regulators of gene expression. Alterations in RBP expression and function are often observed in cancer and influence critical pathways implicated in tumor initiation and growth. Identification and characterization of oncogenic RBPs and their regulatory networks provide new opportunities for targeted therapy.

RESULTS

We identify the RNA-binding protein SERBP1 as a novel regulator of glioblastoma (GBM) development. High SERBP1 expression is prevalent in GBMs and correlates with poor patient survival and poor response to chemo- and radiotherapy. SERBP1 knockdown causes delay in tumor growth and impacts cancer-relevant phenotypes in GBM and glioma stem cell lines. RNAcompete identifies a GC-rich region as SERBP1-binding motif; subsequent genomic and functional analyses establish SERBP1 regulation role in metabolic routes preferentially used by cancer cells. An important consequence of these functions is SERBP1 impact on methionine production. SERBP1 knockdown decreases methionine levels causing a subsequent reduction in histone methylation as shown for H3K27me3 and upregulation of genes associated with neurogenesis, neuronal differentiation, and function. Further analysis demonstrates that several of these genes are downregulated in GBM, potentially through epigenetic silencing as indicated by the presence of H3K27me3 sites.

CONCLUSIONS

SERBP1 is the first example of an RNA-binding protein functioning as a central regulator of cancer metabolism and indirect modulator of epigenetic regulation in GBM. By bridging these two processes, SERBP1 enhances glioma stem cell phenotypes and contributes to GBM poorly differentiated state.

Influence of glioblastoma contact with the subventricular zone on survival and recurrence patterns

BACKGROUND

There is growing evidence that the subventricular zone (SVZ) may be involved in both the initiation and progression of glioblastoma (GB). We aimed to assess tumor proximity to the SVZ as a potential prognostic factor in GB.

METHOD

Retrospective study of 133 patients diagnosed with primary GB who underwent surgery followed by temozolomide-based chemoradiation between 2010 and 2016. All lesions were classified according to their anatomic relation with the SVZ. We determined the effect of tumor contact with the SVZ on progression-free survival (PFS), overall survival (OS), type, and patterns of recurrence.

RESULTS

At a median follow-up of 18.6 months (95% CI 15.9-21.2), PFS and OS were 7.5 (95% CI 6.7-8.3) and 13.9 (95% CI 10.9-16.9) months, respectively. On the univariate analyses, initial contact with the SVZ was a factor for poor prognosis for both PFS (6.1 vs. 8.7 months; p = 0.006) and OS (10.6 vs. 17.9 months; p = 0.037). On the multivariate analysis, tumor contact with the SVZ remained statistically significant for PFS, but not OS. Patients with SVZ-contacting tumors presented a higher rate of aggressive clinical progression (30.9% vs. 11.3%; p = 0.007) and contralateral relapse patterns (23.4% vs. 9.1%; p = 0.048).

CONCLUSIONS

Our results suggest that glioblastoma contact with the SVZ appears to be an independent prognostic factor for poor PFS. The presence of an SVZ-contacting tumor was associated with more aggressive recurrences and a higher rate of contralateral relapses. These findings suggest that this variable may be a new prognostic factor in glioblastoma.

Hypoxia, Inflammation and Necrosis as Determinants of Glioblastoma Cancer Stem Cells Progression

Tumor hypoxic microenvironment causes hypoxia inducible factor 1 alpha (HIF-1α) activation and necrosis with alarmins release. Importantly, HIF-1α also controls the expression of alarmin receptors in tumor cells that can bind to and be activated by alarmins. Human tumor tissues possess 1–2% of cancer stem cells (CSCs) residing in hypoxic niches and responsible for the metastatic potential of tumors. Our hypothesis is that hypoxic CSCs express alarmin receptors that can bind alarmins released during necrosis, an event favoring CSCs migration. To investigate this aspect, glioblastoma stem-like cell (GSC) lines were kept under hypoxia to determine the expression of hypoxic markers as well as receptor for advanced glycation end products (RAGE). The presence of necrotic extracts increased migration, invasion and cellular adhesion. Importantly, HIF-1α inhibition by digoxin or acriflavine prevented the response of GSCs to hypoxia alone or plus necrotic extracts. In vivo, GSCs injected in one brain hemisphere of NOD/SCID mice were induced to migrate to the other one in which a necrotic extract was previously injected. In conclusion, our results show that hypoxia is important not only for GSCs maintenance but also for guiding their response to external necrosis. Inhibition of hypoxic pathway may therefore represent a target for preventing brain invasion by glioblastoma stem cells (GSCs).

Tumoral and immune heterogeneity in an anti-PD-1-responsive glioblastoma: a case study

Clinical benefit of immune checkpoint blockade in glioblastoma (GBM) is rare, and we hypothesize that tumor clonal evolution and the immune microenvironment are key determinants of response. Here, we present a detailed molecular characterization of the intratumoral and immune heterogeneity in an IDH wild-type, MGMT-negative GBM patient who plausibly benefited from anti-PD-1 therapy with an unusually long 25-mo overall survival time. We leveraged multiplex immunohistochemistry, RNA-seq, and whole-exome data from the primary tumor and three resected regions of recurrent disease to survey regional tumor-immune interactions, genomic instability, mutation burden, and expression profiles. We found significant regional heterogeneity in the neoantigenic and immune landscape, with a differential T-cell signature among recurrent sectors, a uniform loss of focal amplifications in EGFR, and a novel subclonal EGFR mutation. Comparisons with recently reported correlates of checkpoint blockade in GBM and with TCGA-GBM revealed appreciable intratumoral heterogeneity that may have contributed to a differential PD-1 blockade response.

System-based approaches as prognostic tools for glioblastoma

BACKGROUND

The evasion of apoptosis is a hallmark of cancer. Understanding this process holistically and overcoming apoptosis resistance is a goal of many research teams in order to develop better treatment options for cancer patients. Efforts are also ongoing to personalize the treatment of patients. Strategies to confirm the therapeutic efficacy of current treatments or indeed to identify potential novel additional options would be extremely beneficial to both clinicians and patients. In the past few years, system medicine approaches have been developed that model the biochemical pathways of apoptosis. These systems tools incorporate and analyse the complex biological networks involved. For their successful integration into clinical practice, it is mandatory to integrate systems approaches with routine clinical and histopathological practice to deliver personalized care for patients.

RESULTS

We review here the development of system medicine approaches that model apoptosis for the treatment of cancer with a specific emphasis on the aggressive brain cancer, glioblastoma.

CONCLUSIONS

We discuss the current understanding in the field and present new approaches that highlight the potential of system medicine approaches to influence how glioblastoma is diagnosed and treated in the future.

Prion Protein in Glioblastoma Multiforme

The cellular prion protein (PrPc) is an evolutionarily conserved cell surface protein encoded by the PRNP gene. PrPc is ubiquitously expressed within nearly all mammalian cells, though most abundantly within the CNS. Besides being implicated in the pathogenesis and transmission of prion diseases, recent studies have demonstrated that PrPc contributes to tumorigenesis by regulating tumor growth, differentiation, and resistance to conventional therapies. In particular, PrPc over-expression has been related to the acquisition of a malignant phenotype of cancer stem cells (CSCs) in a variety of solid tumors, encompassing pancreatic ductal adenocarcinoma (PDAC), osteosarcoma, breast cancer, gastric cancer, and primary brain tumors, mostly glioblastoma multiforme (GBM). Thus, PrPc is emerging as a key in maintaining glioblastoma cancer stem cells’ (GSCs) phenotype, thereby strongly affecting GBM infiltration and relapse. In fact, PrPc contributes to GSCs niche’s maintenance by modulating GSCs’ stem cell-like properties while restraining them from differentiation. This is the first review that discusses the role of PrPc in GBM. The manuscript focuses on how PrPc may act on GSCs to modify their expression and translational profile while making the micro-environment surrounding the GSCs niche more favorable to GBM growth and infiltration.

Connecting signaling and metabolic pathways in EGF receptor-mediated oncogenesis of glioblastoma

As malignant transformation requires synchronization of growth-driving signaling (S) and metabolic (M) pathways, defining cancer-specific S-M interconnected networks (SMINs) could lead to better understanding of oncogenic processes. In a systems-biology approach, we developed a mathematical model for SMINs in mutated EGF receptor (EGFRvIII) compared to wild-type EGF receptor (EGFRwt) expressing glioblastoma multiforme (GBM). Starting with experimentally validated human protein-protein interactome data for S-M pathways, and incorporating proteomic data for EGFRvIII and EGFRwt GBM cells and patient transcriptomic data, we designed a dynamic model for EGFR-driven GBM-specific information flow. Key nodes and paths identified by in silico perturbation were validated experimentally when inhibition of signaling pathway proteins altered expression of metabolic proteins as predicted by the model. This demonstrated capacity of the model to identify unknown connections between signaling and metabolic pathways, explain the robustness of oncogenic SMINs, predict drug escape, and assist identification of drug targets and the development of combination therapies.

Complex and highly dynamic interconnected networks allow cancer to take different routes and circumvent chemotherapy. Therefore, understanding these context-specific networks and their dynamics of molecular interactions driven by different oncogenic signaling and metabolic pathways is very much needed to predict drug targets and the effect of therapeutics. We incorporated high-throughput transcriptome and proteome data into mathematical models to deduce properties of cancer cells through systems biology approach. Here we report the development, testing and validation of an integrated systems biology model of information flow between signaling and metabolic pathways to understand the regulation of the interconnection between them in cancer. Our model efficiently identified unique connections and key nodes important in signaling-metabolic information flow. We predicted some potential novel targets before performing actual drug tests. We have successfully applied this model to identify the interconnections altered in the constitutive signaling of the mutated EGFR by comparing EGF-dependent and wild-type EGFR signaling in glioblastoma multiforme.

The Autophagy Status of Cancer Stem Cells in Gliobastoma Multiforme: From Cancer Promotion to Therapeutic Strategies

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor featuring rapid cell proliferation, treatment resistance, and tumor relapse. This is largely due to the coexistence of heterogeneous tumor cell populations with different grades of differentiation, and in particular, to a small subset of tumor cells displaying stem cell-like properties. This is the case of glioma stem cells (GSCs), which possess a powerful self-renewal capacity, low differentiation, along with radio- and chemo-resistance. Molecular pathways that contribute to GBM stemness of GSCs include mTOR, Notch, Hedgehog, and Wnt/β-catenin. Remarkably, among the common biochemical effects that arise from alterations in these pathways, autophagy suppression may be key in promoting GSCs self-renewal, proliferation, and pluripotency maintenance. In fact, besides being a well-known downstream event of mTOR hyper-activation, autophagy downregulation is also bound to the effects of aberrantly activated Notch, Hedgehog, and Wnt/β-catenin pathways in GBM. As a major orchestrator of protein degradation and turnover, autophagy modulates proliferation and differentiation of normal neuronal stem cells (NSCs) as well as NSCs niche maintenance, while its failure may contribute to GSCs expansion and maintenance. Thus, in the present review we discuss the role of autophagy in GSCs metabolism and phenotype in relationship with dysregulations of a variety of NSCs controlling pathways, which may provide novel insights into GBM neurobiology.

Post-traumatic Glioma: Report of two Cases

We report two cases of brain glioma that developed in the scar of an old brain trauma. The first is that of a 40-year-old man who presented with severe headaches; CT and MRI showed a large mass in the right parietal region. The tumor was unresectable and surgical biopsy showed a glioblastoma multiforme. The patient had suffered a cranial trauma in a road accident 20 years previously with an intrathecal hematoma in the right parietal region. The second case concerns a 60-year-old man who, 15 years after severe head injury in a road accident, developed a glioblastoma multiforme which was localized in the scar of the brain contusion. These cases fulfill the established criteria for a traumatic origin of brain tumors and add further support to the relationship between cranial trauma and the onset of glioma. As stated by other authors, an association between head trauma and brain tumor risk cannot be ruled out and should be studied further.

Proneural-Mesenchymal Transition: Phenotypic Plasticity to Acquire Multitherapy Resistance in Glioblastoma

Glioblastoma (GBM) is an extremely aggressive tumor of the central nervous system, with a prognosis of 12–15 months and just 3–5% of survival over 5 years. This is mainly because most patients suffer recurrence after treatment that currently consists in maximal resection followed by radio- and chemotherapy with temozolomide. The recurrent tumor shows a more aggressive behavior due to a phenotypic shift toward the mesenchymal subtype. Proneural-mesenchymal transition (PMT) may represent for GBM the equivalent of epithelial–mesenchymal transition associated with other aggressive cancers. In this review we frame this process in the high degree of phenotypic inter- and intra-tumor heterogeneity of GBM, which exists in different subtypes, each one characterized by further phenotypic variability in its stem-cell compartment. Under the selective pressure of different treatment agents PMT is induced. The mechanisms involved, as well as the significance of such event in the acquisition of a multitherapy resistance phenotype, are taken in consideration for future perspectives in new anti-GBM therapeutic options.

Comparison of Biomarker Assays for EGFR: Implications for Precision Medicine in Patients with Glioblastoma

PURPOSE

Patients with glioblastoma (GBM) have a poor prognosis and are in desperate need of better therapies. As therapeutic decisions are increasingly guided by biomarkers, and EGFR abnormalities are common in GBM, thus representing a potential therapeutic target, we systematically evaluated methods of assessing EGFR amplification by multiple assays. Specifically, we evaluated correlation among fluorescence in situ hybridization (FISH), a standard assay for detecting EGFR amplification, with other methods.Experimental Design: Formalin-fixed, paraffin-embedded tumor samples were used for all assays. EGFR amplification was detected using FISH (N = 206) and whole-exome sequencing (WES, N = 74). EGFR mRNA expression was measured using reverse transcription-polymerase chain reaction (RT-PCR, N = 206) and transcriptome profiling (RNAseq, N = 64). EGFR protein expression was determined by immunohistochemistry (IHC, N = 34). Significant correlations among various methods were determined using Cohen's kappa (κ = 0.61-0.80 defines substantial agreement) or R 2 statistics.

RESULTS

EGFR mRNA expression levels by RNA sequencing (RNAseq) and RT-PCR were highly correlated with EGFR amplification assessed by FISH (κ = 0.702). High concordance was also observed when comparing FISH to WES (κ = 0.739). RNA expression was superior to protein expression in delineating EGFR amplification.

CONCLUSIONS

Methods for assessing EGFR mRNA expression (RT-PCR, RNAseq) and copy number (WES), but not protein expression (IHC), can be used as surrogates for EGFR amplification (FISH) in GBM. Collectively, our results provide enhanced understanding of available screening options for patients, which may help guide EGFR-targeted therapeutic approaches.

Stearoyl CoA Desaturase Is Essential for Regulation of Endoplasmic Reticulum Homeostasis and Tumor Growth in Glioblastoma Cancer Stem Cells

Inherent plasticity and various survival cues allow glioblastoma stem-like cells (GSCs) to survive and proliferate under intrinsic and extrinsic stress conditions. Here, we report that GSCs depend on the adaptive activation of ER stress and subsequent activation of lipogenesis and particularly stearoyl CoA desaturase (SCD1), which promotes ER homeostasis, cytoprotection, and tumor initiation. Pharmacological targeting of SCD1 is particularly toxic due to the accumulation of saturated fatty acids, which exacerbates ER stress, triggers apoptosis, impairs RAD51-mediated DNA repair, and achieves a remarkable therapeutic outcome with 25%-100% cure rate in xenograft mouse models. Mechanistically, divergent cell fates under varying levels of ER stress are primarily controlled by the ER sensor IRE1, which either promotes SCD1 transcriptional activation or converts to apoptotic signaling when SCD1 activity is impaired. Taken together, the dependence of GSCs on fatty acid desaturation presents an exploitable vulnerability to target glioblastoma.

Glioblastoma in a patient with tuberous sclerosis

Tuberous sclerosis complex (TSC) is a multisystem, autosomal dominant disorder with a wide clinical spectrum. The most common brain tumor associated with TSC is the low grade subependymal giant cell astrocytoma. Reports of high grade primary brain tumors in patients with TSC are rare. TSC1/2 mutation has been identified in glioblastoma (GBM) even though it probably does not increase the overall risk for GBM in patients with TSC. We present a 58-year-old patient with known TSC, admitted for new neurological symptoms, diagnosed with a large heterogeneous tumor involving most of the corpus callosum. Stereotactic needle brain biopsy confirmed the diagnosis to be GBM. Five previously reported similar cases are reviewed, reflecting diversity in clinical and radiological findings and indicating that a high index of clinical suspicion must be maintained in patients with TSC.

Possible effects of radiofrequency electromagnetic fields on in vivo C6 brain tumors in Wistar rats

PURPOSE

Glioblastoma is a malignant brain tumor which has one of the poorest prognosis. It is not clear if toxic environmental factors can influence its aggressiveness. Recently, it was suggested that brain cancer patients with heavy cell phone use showed reduced survival. Here we aimed to assess the effect of controlled brain averaged specific absorption rate (BASAR) from heavy use of cell phone radiofrequency electromagnetic fields (RF-EMF) on in vivo C6 brain tumors in Wistar rats.

METHODS

C6 cells grafted male rats were exposed to GSM 900 MHz signal at environmental BASAR, 0 (sham), 0.25 or 0.5 W/kg (5 days a week, 45 min a day in restraint), or were cage controls (no restraint). At death, tumor volume and immunohistochemistry for CD31, cleaved caspase (CC) 3 and Ki67 were assessed to examine vascularization, apoptosis and cellular divisions, respectively. Moreover, immune cell invasion, necrosis and mitotic index were determined.

RESULTS

Results showed no BASAR effect on survival (31 days post-graft median), tumor volume, mitotic index, vascularization, infiltration, necrosis or cell division. However, results suggested a BASAR-dependent reduction of immune cell invasion and apoptosis.

CONCLUSIONS

Our data suggested an action of RF-EMF by reducing immune cell invasion and glioblastoma cell apoptosis, at probably too low amplitude to impact survival. Further replication studies are needed to confirm these observations.

Secondary Brain Neoplasm after Stereotactic Radiosurgery in Patients with Metastatic Non-small Cell Lung Cancer

Stereotactic radiosurgery (SRS) using the Gamma Knife (GK) is now being increasingly utilized for the treatment of brain metastases. However, there are a few reported cases of SRS-induced brain neoplasms. We herein report the case of a Japanese woman with metastatic non-small cell lung cancer (NSCLC) harboring epidermal growth factor (EGFR)-mutations who was treated four times with a GK for brain metastases. She developed glioblastoma 5.7 years after the initial GK surgery. Radiation-induced secondary neoplasms generally appear after a latency period of several years. Advances in cancer therapy have improved the survival of patients with NSCLC, providing enough time for secondary neoplasms to appear after SRS.

Traumatic glioblastoma: commentary and suggested mechanism

The role of head trauma in the development of glioblastoma is highly controversial and has been minimized since first put forward. This is not unexpected because skull injuries are overwhelmingly more common than glioblastoma. This paper presents a commentary based on the contributions of James Ewing, who established a major set of criteria for the recognition of an official relationship between trauma and cancer. Ewing's criteria were very stringent. The scholars who succeeded Ewing have facilitated the characterization of traumatic brain injuries since the introduction of computed tomography and magnetic resonance imaging. Discussions of the various criteria that have since developed are now being conducted, and those of an unnecessarily limiting nature are being highlighted. Three transcription factors associated with traumatic brain injury have been identified: p53, hypoxia-inducible factor-1α, and c-MYC. A role for these three transcription factors in the relationship between traumatic brain injury and glioblastoma is suggested; this role may support a cause-and-effect link with the subsequent development of glioblastoma.

Glioblastoma Multiforme and Breast Cancer: Report on 11 Cases and Clinico-Pathological Remarks

The association between breast cancer and glioblastoma multiforme has not been amply analyzed in the literature. We describe 11 female patients with a diagnosis of glioblastoma multiforme who were treated when younger for breast cancer. We believe that this association is not due to chance but rather to genetic changes in hormone status and in particular to sex hormones. Another important point of view is represented by the chemotherapy treatment of breast cancer, which could have a carcinogenic effect and explain the growth of glioblastoma. This consideration, in our opinion, is important, because more effort should be made to understand the pathogenesis of glioblastoma multiforme and to improve the therapeutic approaches.

Toxicity and Efficacy of a Novel GADD34-expressing Oncolytic HSV-1 for the Treatment of Experimental Glioblastoma

Purpose: Glioblastoma (GBM) is the most common primary central nervous system cancer in adults. Oncolytic HSV-1 (oHSV) is the first FDA-approved gene therapy approach for the treatment of malignant melanoma. For GBM, oHSVs need to be engineered to replicate within and be toxic to the glial tumor but not to normal brain parenchymal cells. We have thus engineered a novel oHSV to achieve these objectives.Experimental Design: NG34 is an attenuated HSV-1 with deletions in the genes encoding viral ICP6 and ICP34.5. These mutations suppress virus replication in nondividing brain neurons. NG34 expresses the human GADD34 gene under transcriptional control of a cellular Nestin gene promoter/enhancer element, whose expression occurs selectively in GBM. In vitro cytotoxicity assay and survival studies with mouse models were performed to evaluate therapeutic potency of NG34 against glioblastoma. In vivo neurotoxicity evaluation of NG34 was tested by intracerebral inoculation.Results: NG34 replicates in GBM cells in vitro with similar kinetics as those exhibited by an oHSV that is currently in clinical trials (rQNestin34.5). Dose-response cytotoxicity of NG34 in human GBM panels was equivalent to or improved compared with rQNestin34.5. The in vivo efficacy of NG34 against two human orthotopic GBM models in athymic mice was similar to that of rQNestin34.5, whereas intracerebral injection of NG34 in the brains of immunocompetent and athymic mice showed significantly better tolerability. NG34 was also effective in a syngeneic mouse glioblastoma model.Conclusions: A novel oHSV encoding GADD34 is efficacious and relatively nontoxic in mouse models of GBM. Clin Cancer Res; 24(11); 2574-84. ©2018 AACR.

Glioblastoma and ABO blood groups: further evidence of an association between the distribution of blood group antigens and brain tumours

BACKGROUND

Glioblastoma is a highly malignant brain tumour that usually leads to death. Several studies have reported a link between the distribution of ABO blood group antigens and a risk of developing specific types of cancer, although no consensus has been reached. This study aims to investigate the relationship between the distribution of ABO blood group antigens and the incidence of glioblastoma.

MATERIALS AND METHODS

The study cohort consisted of 115 glioblastoma patients who were diagnosed at King Abdullah University Hospital, Jordan, between 2004 and 2015. Three different patient populations made up three control groups and these were selected from among patients at the same institution between 2014 and 2015 as follows: 3,847 healthy blood donors, 654 accidental trauma patients admitted to the Departments of Neurosurgery and Orthopaedics, and 230 age- and sex-matched control subjects recruited blindly from the Departments of Paediatrics and Internal Medicine.

RESULTS

There was a significant association between the distribution of ABO blood group antigens and the incidence of glioblastoma. Post hoc residual analysis revealed that individuals with group A had a higher than expected chance of developing glioblastoma, while individuals with group O had a lower than expected chance. Furthermore, individuals with group A were found to be at a 1.62- to 2.28-fold increased risk of developing glioblastoma compared to individuals with group O.

DISCUSSION

In the present study, we demonstrate that, in Jordan, individuals with group A have an increased risk of developing glioblastoma, while individuals with group O have a reduced risk. These findings suggest that the distribution of ABO blood group antigens is associated with a risk of brain tumours and may play an important role in their development. However, further clinical and experimental investigations are required to confirm this association.

Glioblastoma in the Canton of Zurich, Switzerland revisited: 2005 to 2009

BACKGROUND

A population-based analysis of patients with glioma diagnosed between 1980 and 1994 in the Canton of Zurich in Switzerland confirmed the overall poor prognosis of glioblastoma. To explore changes in outcome, registry data were reevaluated for patients diagnosed between 2005 and 2009.

METHODS

Patients with glioblastoma who were diagnosed between 2005 and 2009 were identified by the Zurich and Zug Cancer Registry. The prognostic significance of epidemiological and clinical data, isocitrate dehydrogenase 1 (IDH1)(R132H) mutation status, and O6 methylguanine DNA methyltransferase (MGMT) promoter methylation status was analyzed using the Kaplan-Meier method and the Cox proportional hazards model.

RESULTS

A total of 264 patients with glioblastoma were identified, for an annual incidence of 3.9 compared with the previous incidence of 3.7. The mean age of the patients at the time of diagnosis was 59.5 years in the current cohort compared with 61.3 years previously. The overall survival (OS) rate was 46.4% at 1 year, 22.5% at 2 years, and 14.4% at 3 years in the current study compared with 17.7% at 1 year, 3.3% at 2 years, and 1.2% at 3 years as reported previously. The median OS for all patients with glioblastoma was 11.5 months compared with 4.9 months in the former patient population. The median OS was 1.9 months for best supportive care, 6.2 months for radiotherapy alone, 6.7 months for temozolomide alone, and 17.0 months for radiotherapy plus temozolomide. Multivariate analysis revealed age, Karnofsky performance score, extent of tumor resection, first-line treatment, year of diagnosis, and MGMT promoter methylation status were associated with survival in patients with IDH1(R132H) -nonmutant glioblastoma.

CONCLUSIONS

The OS of patients newly diagnosed with glioblastoma in the Canton of Zurich in Switzerland markedly improved from 1980 through 1994 to 2005 through 2009. Cancer 2016;122:2206-15. © 2016 American Cancer Society.

JC polyomavirus in the aetiology and pathophysiology of glial tumours

Glial brain tumours with their poor prognosis, limited treatment modalities and unclear detailed pathophysiology represent a significant health concern. The purpose of the current study was to investigate and describe the possible role of the human polyomavirus JC as an underlying cancerogenic or co-cancerogenic factor in the complex processes of glial tumour induction and development. Samples from 101 patients with glial tumours were obtained during neurosurgical tumour resection. Small tissue pieces were taken from several areas of the histologically verified solid tumour core. Biopsies were used for DNA extraction and subsequent amplification reactions of sequences from the JC viral genome. Real-time polymerase chain reaction was used for detection and quantification of its non-coding control region (NCCR) and gene encoding the regulatory protein Large T antigen (LT). An average of 37.6% of all patients was found to be LT positive, whereas only 6.9% tested positive for NCCR. The analysis of the results demonstrated significant variance between the determined LT prevalence and the rate for NCCR, with a low starting copy number in all positive samples and threshold cycles in the range of 36 to 42 representing viral load in the range from 10 to 1000 copies/μl. The results most probably indicate incomplete JC viral replication. Under such conditions, mutations in the host cell genome may be accumulated due to interference of the virus with the host cell machinery, and eventually malignant transformation may occur.

The in vitro effects of caffeine on viability, cycle cycle profiles, proliferation, and apoptosis of glioblastomas

OBJECTIVE

We studied the effects of caffeine on cell viability, cell cycle profiles, proliferation, and apoptosis in rat C6 and human U87MG glioblastoma cell lines.

MATERIALS AND METHODS

Cell viability was quantified by the methyl thiazolyl tetrazolium (MTT) assay. Flow cytometry was used to quantify the relative number of cells in different phases of the cell cycle, while cell proliferation was quantified using the Cell Counting Kit-8. The proportion of apoptotic cells was determined by flow cytometry, and expression of apoptosis-related proteins Caspase-3, Cyt-C, Bax and Bcl-2 by Western blot.

RESULTS

Caffeine at doses of up to 0.5 mM did not affect cell viability in both rat C6 and human U87MG glioblastoma cells. Further studies were done using the dose of 0.5 mM. Percentage of cells in the G0/G1 phase was markedly increased, while percentage of cells in the S phase decreased, after cell treatment with caffeine. Cell proliferation was significantly inhibited by caffeine. Furthermore, caffeine induced cell apoptosis, decreased expression of Bcl-2, and increased expression of Cyt-C and Caspase-3.

CONCLUSIONS

Caffeine inhibits proliferation and induces apoptosis in glioblastoma cells. Our results provide the experimental basis for further studies of potential role of caffeine in the treatment of glioblastomas.

[Epidermic growth factor receptor (EGFR) in glioblastomas: the mechanism of tumorigenesis and its role as a therapeutic target]

A glioblastoma is a primary brain tumour that is very aggressive and resistant to conventional treatment with chemo- or radiotherapy. Given that epidermic growth factor receptor (EGFR) is altered in 50% of glioblastomas, it is currently one of the most promising therapeutic targets in this kind of tumour. Yet, inhibitors of the kinase activity of EGFR have yielded poor results in clinical trials with patients with glioblastomas. In this review we analyse the function of EGFR in glioblastomas and outline the therapeutic approaches aimed against this receptor in this kind of tumour. This sort of analysis could be a starting point for improving the design of future therapies for glioblastomas, based on inhibiting the EGFR function.

Glioblastoma after AVM radiosurgery. Case report and review of the literature

BACKGROUND

Stereotactic radiosurgery (SRS) is considered to be a relatively safe procedure in cerebral arteriovenous malformation management. There are very few reported cases of SRS-associated/induced malignancies.

METHODS

We show the case of a 21-year-old female who presented with a 21-mm(3) ruptured AVM in the right mesial frontocallosal region. Embolization and/or radiosurgery was proposed. She preferred radiosurgery. The AVM was treated with CyberKnife(®) SRS.

RESULTS

She presented behavior changes 6 years after SRS. MRI showed a right subcortical frontal lesion with increased perfusion, more consistent with high-grade glioma. The lesion's center was within the irradiated region of the previous SRS, having received an estimated radiation dose of 4 Gy. Pathological examination noted a hypercellular tumor showing astrocytic tumor cells with moderate pleomorphism in a fibrillary background, endothelial proliferation, and tumor necrosis surrounded by perinecrotic pseudopalisades. Numerous mitotic figures were seen. The appearances were those of glioblastoma, WHO grade IV, with neuronal differentiation. SRS-associated/-induced GBM after treatment of a large AM is exceptional. SRS-associated/-induced malignancies are mostly GBMs and occur on average after a latency of 9.4 years, within very low-dose peripheral regions as well as the full-dose regions; 33.3 % of patients were under 20 years at the time of SRS, and in 66 % the lesion treated was a vascular pathology.

CONCLUSION

Although it is unlikely that the risk of radiation-induced cancer will change the current standard of practice, patients must be warned of this potential possibility before treatment.

A pooled multisite analysis of the effects of atopic medical conditions in glioma risk in different ethnic groups

PURPOSE

The incidences of atopic conditions (allergies, asthma, or eczema) and glioma vary by ethnicity. Atopic conditions are inversely associated with gliomas. We conducted a pooled multisite study investigating the associations of atopic conditions with glioma in different race/ethnicity groups.

METHODS

Using glioma cases and healthy controls, unconditional logistic regression was conducted to assess the associations of atopic conditions with glioma separately in white, black, Asian, and Hispanic subpopulations. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

Glioblastoma multiforme cases were less likely than controls to report a history of atopic conditions in whites (OR = 0.46, [95% CI, 0.38-0.54]) and Asians (OR = 0.27, [95% CI, 0.10-0.73]). The same trend was seen when looking at glioma cases of all histologies. An inverse association was not seen in blacks for glioblastoma multiforme or all histologies combined.

CONCLUSIONS

The inverse association between glioma and atopic conditions may vary by ethnicity due to a difference in the biology of atopic conditions in different ethnicities but may be due to chance because of the limitations of small nonwhite sample sizes.

The role of inflammation in brain cancer

Malignant brain tumors are among the most lethal of human tumors, with limited treatment options currently available. A complex array of recurrent genetic and epigenetic changes has been observed in gliomas that collectively result in derangements of common cell signaling pathways controlling cell survival, proliferation, and invasion. One important determinant of gene expression is DNA methylation status, and emerging studies have revealed the importance of a recently identified demethylation pathway involving 5-hydroxymethylcytosine (5hmC). Diminished levels of the modified base 5hmC is a uniform finding in glioma cell lines and patient samples, suggesting a common defect in epigenetic reprogramming. Within the tumor microenvironment, infiltrating immune cells increase oxidative DNA damage, likely promoting both genetic and epigenetic changes that occur during glioma evolution. In this environment, glioma cells are selected that utilize multiple metabolic changes, including changes in the metabolism of the amino acids glutamate, tryptophan, and arginine. Whereas altered metabolism can promote the destruction of normal tissues, glioma cells exploit these changes to promote tumor cell survival and to suppress adaptive immune responses. Further understanding of these metabolic changes could reveal new strategies that would selectively disadvantage tumor cells and redirect host antitumor responses toward eradication of these lethal tumors.

Associations of high-grade glioma with glioma risk alleles and histories of allergy and smoking

Glioma risk has consistently been inversely associated with allergy history but not with smoking history despite putative biologic plausibility. Data from 855 high-grade glioma cases and 1,160 controls from 4 geographic regions of the United States during 1997-2008 were analyzed for interactions between allergy and smoking histories and inherited variants in 5 established glioma risk regions: 5p15.3 (TERT), 8q24.21 (CCDC26/MLZE), 9p21.3 (CDKN2B), 11q23.3 (PHLDB1/DDX6), and 20q13.3 (RTEL1). The inverse relation between allergy and glioma was stronger among those who did not (odds ratio(allergy-glioma) = 0.40, 95% confidence interval: 0.28, 0.58) versus those who did (odds ratio(allergy-glioma) = 0.76, 95% confidence interval: 0.59, 0.97; P(interaction) = 0.02) carry the 9p21.3 risk allele. However, the inverse association with allergy was stronger among those who carried (odds ratio(allergy-glioma) = 0.44, 95% confidence interval: 0.29, 0.68) versus those who did not carry (odds ratio(allergy-glioma) = 0.68, 95% confidence interval: 0.54, 0.86) the 20q13.3 glioma risk allele, but this interaction was not statistically significant (P = 0.14). No relation was observed between glioma risk and smoking (odds ratio = 0.92, 95% confidence interval: 0.77, 1.10; P = 0.37), and there were no interactions for glioma risk of smoking history with any of the risk alleles. The authors' observations are consistent with a recent report that the inherited glioma risk variants in chromosome regions 9p21.3 and 20q13.3 may modify the inverse association of allergy and glioma.

Therapy-associated secondary tumors in patients with non-germinomatous malignant germ cell tumors

We report three patients with non-germinomatous malignant germ cell tumor (NGMGCT) who developed therapy-associated secondary tumors. They were diagnosed as having NGMGCT by elevated serum levels of α-fetoprotein (AFP), human chorionic gonadotropin (HCG), or β-HCG. Preoperatively, all patients received a combination of etoposide and platinum-based chemotherapy and radiotherapy; neo-adjuvant therapy (NAT) was followed by complete excision of the residual tumor. Postoperatively, all underwent maintenance chemotherapy and all remained free of NGMGCT without recurrence. However, they developed therapy-associated secondary tumors, i.e. glioblastoma, meningioma, or cavernous angioma after 10.1, 9.8, and 8.2 years, respectively. The patient with glioblastoma died one year after its detection. The other two patients are currently alive; the meningioma was completely removed and the cavernous angioma is being monitored without additional treatment. To the best of our knowledge, therapy-associated secondary tumors in patients treated for NGMGCT are rare.

Association between body mass index and mortality in patients with glioblastoma mutliforme

PURPOSE

To examine the association between obesity and survival in patients with glioblastoma mutliforme (GBM) METHODS: Using a prospective design, 1,259 patients with previously untreated GBM were recruited between 1991 and 2008. Height and weight were self-reported or abstracted from medical records at study entry and used to calculate body mass index (BMI) [weight (kg)/[height (m)](2). Cox proportional models were used to estimate the risk of death associated with BMI as a continuous variable or categorized using established criteria (normal weight, 18.5-24.9 kg/m(2); overweight, 25.0-29.9 kg/m(2); obese, ≥ 30.0 kg/m(2)).

RESULTS

Median follow-up was 40 months, and 1,069 (85%) deaths were observed during this period. For all patients, minimal adjusted analyses indicated no significant association between BMI treated as a continuous variable and survival. Compared with patients with a BMI 18.5-24.9 kg/m(2), the minimally adjusted HR for overall survival was 1.08 (95% CI, 0.94-1.24) for a BMI 25-29.9 kg/m(2) and 1.08 (95% CI, 0.91-28) for a BMI ≥ 30.0 kg/m(2). After additional adjustment for adjuvant therapy, the HR for those with a BMI of 25.0-29.9 kg/m(2) was 1.14 (95% CI, 0.99-1.32) and 1.09 (95% CI, 0.91-1.30) for those with a BMI ≥ 30.0 kg/m(2). No significant interactions were revealed for BMI and any demographic variables.

CONCLUSION

BMI was not associated with survival in newly diagnosed and previously untreated patients with GBM. Further research investigating the prognostic significance of alternative, quantitative measures of body habitus, and functional performance are required.

Glioblastoma and dementia may share a common cause

The cause of most glioblastomas is unknown. One cause might lie in the surrounding brain tissue. The interactions between glioblastoma cells and their micro- and macro-environment could create a context that promotes or suppresses tumor growth and protects or exposes the malignant cells to immune attack. Alzheimer's disease has been identified as a protein misfolding disorder (proteopathy), caused by accumulation of abnormally folded A-beta and tau proteins in the brain. These or other changed proteins or as yet unrecognized biochemical brain changes of dementia might promote glioblastoma development. Published data indicate that there is an association between Alzheimer's disease prevalence and malignant brain tumor incidence in 19 US states. Hypothetically, Alzheimer's and glioblastoma may share an as yet unknown peripheral tissue pathway that can promote the progression of both diseases. If this pathway can be identified, new treatments for both conditions may follow.

Intravascular thrombosis in central nervous system malignancies: a potential role in astrocytoma progression to glioblastoma

The presence of necrosis within a diffuse glioma is a powerful predictor of poor prognosis, yet little is known of its origins. Intravascular thrombosis is a frequent finding in glioblastoma [GBM; World Health Organization (WHO) grade IV] specimens and could potentially be involved in astrocytoma progression to GBM or represent a surrogate marker of GBM histology. We investigated whether intravascular thrombosis was more frequent or prominent in GBM than other central nervous system (CNS) malignancies and considered its prognostic significance in anaplastic astrocytoma (AA; WHO grade III), which lacks necrosis. Histologic sections were examined for thrombosis, necrosis and microvascular hyperplasia from each of 297 CNS tumors, including 103 GBMs, 46 AAs, 20 diffuse astrocytoma (DAs; WHO grade II), eight anaplastic oligodendrogliomas (AOs; WHO grade III), 20 oligodendrogliomas (ODs; WHO grade II), 49 metastatic carcinomas (METs), 31 primary central nervous system lymphomas (PCNSLs) and 20 medulloblastomas (MBs). Among newly diagnosed tumors, thrombosis was present in 92% of GBM resections, significantly greater than other types of CNS malignancies. Of tumors with thrombosis, GBMs had a higher frequency of affected vessels than AAs, DAs, AOs, ODs and MBs, but had a frequency similar to METs and PCNSLs. The sensitivity of thrombosis for the diagnosis of GBM in this set of tumors was 92% and the specificity was 91%. Intravascular thrombosis was uncommon in AAs and was only noted in stereotactic biopsies. This subset of patients had shorter survivals than those AAs without thrombosis. Thus, intravascular thrombosis is more frequent in GBM than other CNS malignancies. When present in AAs, it appears to indicate aggressive clinical behavior.

[Radiotherapy induced glioblastoma in a child previously treated for cerebellar medulloblastoma (case report and review of the literature)]

Malignant gliomas represent the most frequent radiotherapy induced ("secondary") solid tumor. Their prognosis remains extremely poor despite of aggressive multimodal treatment. We present a case report of a 16 years old boy who developed cerebellar glioblastoma six years following the combined treatment for medulloblastoma. Clinical history, pathological and cytogenetic findings of the case are discussed along with treatment possibilities.

Téléphone mobile, risque de tumeurs cérébrales et du nerf vestibuloacoustique: l'étude cas-témoins INTERPHONE en France

BACKGROUND

Use of cell phones has increased dramatically since 1992 when they were first introduced in France. Certain electromagnetic fields (at extremely low frequency) have been recognized as possibly carcinogenic by the International Agency for Research on Cancer. Given the use of radiofrequency technology in cell phones, the rapid increase in the number of cell phones has generated concerns about the existence of a potential health hazard. To evaluate the relationship between the use of cell phones and the development of tumors of the head, a multicentric international study (INTERPHONE), coordinated by the International Agency for Research on Cancer, was carried out in 13 countries. This publication reports the results of the French part of the INTERPHONE study.

METHODS

INTERPHONE is a case-control study focused on tumors of the brain and central nervous system: gliomas, meningiomas and neuromas of cranial nerves. Eligible cases were men and women, residents of Paris or Lyon, aged 30-59, newly diagnosed with a first primary tumor between February 2001 and August 2003. The diagnoses were all either histologically confirmed or based upon unequivocal radiological images. Controls were matched for gender, age (+/-5 years) and place of residence. They were randomly drawn from electoral rolls. Detailed information was collected for all subjects during a computer-assisted face-to-face interview. Conditional logistic regression was used to estimate the odds ratio (OR) for an association between the use of cell phones and risk of each type of cancer.

RESULTS

Regular cell phone use was not associated with an increased risk of neuroma (OR=0,92; 95% confidence interval=[0.53-1.59]), meningioma (OR=0,74; 95% confidence interval=[0.43-1.28]) or glioma (OR=1.15; 95% confidence interval=[0.65-2.05]). Although these results are not statistically significant, a general tendency was observed for an increased risk of glioma among the heaviest users: long-term users, heavy users, users with the largest numbers of telephones.

CONCLUSION

No significant increased risk for glioma, meningioma or neuroma was observed among cell phone users participating in Interphone. The statistical power of the study is limited, however. Our results, suggesting the possibility of an increased risk among the heaviest users, therefore need to be verified in the international INTERPHONE analyses.

Glioblastoma multiforme after stereotactic radiotherapy for acoustic neuroma: case report and review of the literature

Indications for the use of radiotherapy in the management of a variety of benign intracranial neoplastic and nonneoplastic pathologies are increasing. Although the short-term risks are minimal, the long-term risks of radiation-induced de novo secondary neoplasms or malignant progression of the primary benign tumor need to be considered. There are currently 19 reported cases of tumors linked with stereotactic radiotherapy/radiosurgery, to which we add our second institutional experience of a patient who succumbed to a glioblastoma multiforme (GBM) after stereotactic radiotherapy for an acoustic neuroma (AN). Review of these 20 cases revealed 10 de novo secondary tumors, of which eight were malignant, with six being malignant gliomas. The majority of the cases (14 of 20) involved AN, with most being in patients with neurofibromatosis-2 (NF2; 8 of 14), reflecting the large numbers and long-term use of radiotherapy for AN. Accelerated growth of the primary benign AN, some 2 to 6 years after focused radiotherapy, was found in six of eight NF2 patients, with pathological verification of a malignant nerve sheath tumor documented in most. The exact carcinogenic risk after radiotherapy is unknown but likely extremely low. However, the risk is not zero and requires discussion with the patient, with specific consideration in young patients and those with a cancer predisposition.