Types Of Glioblastoma Multiforme Research Articles

BIOM-40. THERABIOME-GBM: THERAPEUTIC OUTCOMES RELATED TO GUT MICROBIOME IN GLIOBLASTOMA (GBM) PATIENTS RECEIVING CHEMO-RADIATION: A PROSPECTIVE OBSERVATIONAL STUDY

Abstract PURPOSE A major barrier to improving outcomes in glioblastoma multiforme (GBM) is overcoming a heavily immunosuppressed tumor and systemic environment, as demonstrated by several negative phase III randomized studies of nivolumab in both newly diagnosed and recurrent GBM. In several mouse avatar and human studies across several tumor cohorts including in a humanized microbiome GBM model, re-establishing a new gut microbiome (GM) via fecal transplantation led to tumor responses to PD-1/PD-L1 inhibition. A recent scoping review confirmed a paucity of GM clinical data of a uniform GBM cohort with adequate longitudinal GM sample collection. We are conducting a single-center prospective observational study to establish the feasibility of collecting stool samples throughout the time course of GBM treatment and upon recurrence, and to understand the gut microbiome dynamics of newly diagnosed IDH-wild type (WT) GBM patients. METHODS Patients with newly diagnosed unifocal IDH-1 R132H WT WHO grade 4 GBM, ECOG 0-2, at least 70% tumor resected with plan to receive temozolomide-radiation (TMZ-RT) and adjuvant TMZ +/- Tumor Treating Fields are eligible. Stool samples will be collected prior to TMZ-RT, 4 weeks after TMZ-RT, after adjuvant TMZ, and upon recurrence. The primary endpoint is feasibility, defined as stool sample obtained pre-RT, post-RT (pre-adjuvant TMZ), and at time of recurrence in ≥ 70% of enrolled participants, 75% of target sample size enrolled within 2 years, and stool sample volume and quality sufficient for analysis in ≥ 75% of collected samples. Secondary endpoints include progression-free survival (PFS) in pre-defined GM subgroups, GM taxonomy and diversity in late vs. early progressors, and GM differences in patients with and without post-RT necrosis. Age, sex, race, concurrent medication, corticosteroid use, and diet will be carefully accounted for. Patient reported outcomes using EORTC-QLQ-BN20 and QLQ-C30 will be collected at baseline, 3-, 6-, 9-, and 12-months.

BIOS-02. RECAPITULATE TUMOR DIVERSION AND SPATIAL PATTERNING IN GLIOBLASTOMA BACKGROUND

Abstract BACKGROUND Intra-tumoral heterogeneity of glioblastoma multiforme (GBM) drives aggressive behavior and intrinsic therapeutic resistance. To investigate heterogeneity, high-resolution sequencing techniques provided us to feature tumor molecular subtyping and simulate differentiation. In our study, we proposed to dissect tumor heterogeneity in different anatomical regions by single cell transcriptome analysis. Material and Method We performed single-cell RNA sequencing on 10675 adult IDH-wild type GBM cells from six pairs of tumor core (central necrotic part of tumor) and tumor margin (junction between tumor and brain). Subtyping following RNA velocity was performed to investigate tumor diversity. Result Four subgroups of tumor cells (OPC-like (oligoprogenitor cell), NPC-like (neuroprogenitor cell), AC-like (astrocyte), and MES-like (mesenchymal) )were identified. The higher cell population of OPC/NPC at tumor margin and AC/MES at tumor core was found. The RNA velocity analysis showed the major diversity order was OPC at margin, OPC at core, NPC at margin, and AC with MES at core. CONCLUSION We explore the spatial pattern of tumorigenesis of GBM that OPC at margin part could be the tumor initiating cell. Further investigation of biological characteristics of OPC could be the strategies to block tumor differentiation and progression.

Modulation of Tumor Immune Microenvironment and Prognostic Value of Ferroptosis-Related Genes, and Candidate Target Drugs in Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is the most common type of malignant brain tumor, among which IDH1-wild type GBM has a poor prognosis. Recent studies have shown that ferroptosis-related genes (FRGs) are correlated with the development and progression of cancer. In GBM, the role of FRGs associated with IDH1 status as biological indicators and therapeutic targets remains to be clarified. Ten of FRGs (STEAP3, HSPB1, MAP1LC3A, SOCS1, LOX, CAPG, CP, GDF15, CDKN1A, and CD44) associated with IDH1 status in GBM were identified as key genes through screening by survival analysis and Random Forest using The Cancer Genome Atlas (TCGA) datasets, and the protein expressions of key genes were verified. Transwell and qPCR results showed that ferroptosis promoted the migration of glioblastoma cells and affected the expression of key genes. Our study established the ferroptosis-related prognostic model for GBM patients based on ten key genes by a different modeling method from previous study, the GSVA algorithm. Further, we took the methods of functional enrichment analysis, clinical characteristics, immune cell infiltration, immunomodulator, ESTIMATE and single nucleotide variant (SNV) analysis to study the molecular mechanisms of prognostic model and key genes. The results showed that ten key genes were strongly associated with immune-related factors and were significantly involved in the p53 signaling pathway, senescence and autophagy in cancer, and in the negative regulation of protein kinase activity. Moreover, potential therapeutic drugs were identified by Virtual Screening and Molecular Docking. Our study indicated that the novel ferrotosis-related prognostic model for GBM patients and key genes possessed the prognostic and therapeutic values.

The role of IDH1 mutation on gene expression in glioblastoma

Glioblastoma multiforme (GBM) is the most malignant primary brain tumor found in humans. Mutations in isocitrate dehydrogenases 1 (IDH1R132H) was observed in GBM. GBMs with IDH1R132H have longer patient survival compared to GBMs with wild-type IDH1 and identifying the mechanism of this can contribute to the development of a new treatment for GBM. To investigate the role of IDH1R132H on gene expression, we incorporated three expression arrays from GEO including GSE36245, GSE131837, and GSE122586, and one expression array from TCGA which in total investigate gene expression differences between 293 wild type and 41 mutant IDH1 GBM samples. Meta-DE package in R software was applied to screen the differentially expressed genes (DEGs) between IDH1 wild type and IDH1R132H GBMs. DEGs were used to construct co-expression networks by WGCNA package for TCGA data and genes of the detected module were used to build protein-protein interaction (PPI) network. Each of the mentioned expression arrays was analyzed independently using limma package by cutoff |logFC| > 1 and P.value < 0.05, and 13 downregulated and 26 upregulated common genes were identified. By merging the results of limma package and core genes of the PPI network, 10 hub genes including ARAP3, ARHGAP11B, BDNF, CFAP45, CXCL8, MMP9, RHOBTB1, SHH, SYNJ2, and VEGFA were identified. Based on the TCGA database, we tested the prognostic significance of the detected genes using Kaplan-Meier survival analysis. In conclusion, the results suggested that the hub genes may play role in GBM pathogeny.

The positive feedback loop of NHE1-ERK phosphorylation mediated by BRAFV600E mutation contributes to tumorigenesis and development of glioblastoma

The v-raf murine sarcoma viral oncogene homolog B1 (BRAF) activating mutation V600E (BRAFV600E) is involved in glioblastoma multiforme (GBM). Na/H exchanger 1 (NHE1), a main pH regulator affecting cell microenvironment, is hyper-expressed in GBM. However, the relationship between BRAFV600E signal pathway and NHE1 in GMB cells remains unclear. This study found that NHE1 was a downstream target of BRAFV600E and an upstream factor of extracellular signal-regulated kinase (ERK). In addition, there was a positive feedback loop between NHE1-ERK phosphorylation under regulation of BRAFV600E mutation contributing to the proliferation and invasion of GBM cells. Moreover, the proliferation and invasion abilities of BRAFV600E-mutant and BRAF wild type GBM cells were all suppressed by the NHE1 inhibitor, BRAFV600E inhibitor and combination of them. The inhibitory effect of combination of the two inhibitors was better than each single drug both in vitro and in vivo. Combination of BRAFV600E and NHE1 inhibitors could be considered as a new therapeutic regimen for GBM, especially for GBM with BRAFV600E.

Combined Surgical Resection and Laser Interstitial Thermal Therapy for Glioblastoma: Technical Note.

Glioblastoma multiforme (GBM) is an aggressive intracranial malignancy that confers a poor prognosis despite maximum surgical resection and chemoradiotherapy. Survival decreases further with deep-seated lesions. Laser interstitial thermal therapy (LITT) is an emerging minimally invasive technique for tumor ablation shown to reduce tumor burden effectively, particularly in deep-seated locations less amenable to gross total resection. We describe our initial technical experience of using the combination of LITT followed by surgical resection in patients with GBMs that exhibit both an easily accessible and deep-seated component. Patients with GBM who received concurrent LITT and surgical resection at our institution were identified. Patient demographic and clinical information was procured from the University of Texas MD Anderson Cancer Center electronic medical record along with preoperative, postoperative, and 1-month follow-up magnetic resonance imaging (MRI). Four patients (n = 2 male, n = 2 female) with IDH-wild type GBM who received combined LITT and surgical resection were identified and analyzed retrospectively. All patients received chemoradiotherapy before presentation. All but one patient (75%) received resection before presentation. Median age was 54 years (range: 44-56 years). Median length of hospital stay was 6.5 days (range: 2-47 days). Median extent of combined ablation/resection was 90.4%. One of the four patients experienced complications in the perioperative or immediate follow-up periods. Local recurrence was observed in one patient during the follow-up period. Malignant gliomas in deep-seated locations or in close proximity to white matter structures are challenging to manage. LITT followed by surgical resection may provide an alternative for tumor debulking that minimizes potential morbidities and extent of residual tumor. Further studies comparing this approach with standard resection techniques are warranted.

CBMS-04 SIGNIFICANT ROLE OF HYPOXIA IN THE EXPRESSION AND FUNCTION OF OSTEOPONTIN IN CD44-HIGHLY EXPRESSED GLIOMA STEM-LIKE CELLS IN TUMOR PROGRESSION OF GLIOBLASTOMA

The poor prognosis of glioblastoma multiforme (GBM) may be due to the surviving glioma stem-like cells (GSCs) in the tumor periphery after tumor resection. We demonstrated that CD44-expressed GSCs existed much more in the tumor periphery of high invasive (HI) type GBM than low invasive (LI) type GBM. The HI type was significantly associated with worse outcome, but how GSCs with high CD44 expression relate to tumor progression remains unknown. In this study, we investigated effects of hypoxia on CD44-directed signal pathways, leading to tumor invasion and proliferation in GBM. We focused on the CD44 ligand osteopontin (OPN) because it is known hypoxia affects the interaction of CD44 and OPN which promotes stemness and proliferation of cancer stem cells. We examined mRNA expressions of hypoxia inducible factor (HIF)-1a, HIF-2a, CD44 and OPN in tumor tissues of GBM and investigated effects of hypoxia (1%O2:severe or 5%O2:moderate) on the expression of these molecules using cultured GSCs that were established from tumor tissues showing high CD44 expression in the periphery of GBMs. In addition, we analyzed the effects of OPN on invasive, migratory and proliferative activities of GSCs under the hypoxic conditions. OPN was much higher expressed in the tumor periphery of LI type GBM than HI type GBM. Severe hypoxia significantly increased the expressions of HIF-1a and CD44 but did not OPN. On the other hands, moderate hypoxia promoted the expressions of HIF-2a and OPN. Knockdown of HIF-2a significantly inhibited OPN expression. In addition, the more OPN was expressed in the cultured GSCs under moderate hypoxia, the more the GSCs proliferated and decreased their invasive and migratory activities. In conclusion, GSCs existing in the tumor periphery of GBM can migrate or proliferate by changing CD44-directed signal pathways. Moderate hypoxia promoted HIF-2a/OPN/CD44 pathway, resulting in phenotypic transition to high proliferative tumors.

Ion beams for space radiation radiobiological effect studies

Space radiation exposures to the heavier particles found in galactic cosmic rays (GCR) present a risk in manned space travel, particularly to the central nervous system (CNS). GCR are made up of a mixture of multiple charged particles such as protons, 4He, and 56Fe heavy ions. The most harmful to the CNS are the more highly charged and energetic (HZE) particles, including 56Fe because of their significant biological effect contribution to GCR dose and high linear energy transfer. These HZE particles can result in altered cognitive function, reduced motor function and behavioural changes and long term chronic brain disease. There is currently a lack of data on the biological response to 56Fe ions. In this regard, ground based experiments could be used to infer the effects of the cosmic environment on cell survival. A mono-energetic beam of 56Fe ions was generated by the Heavy Ion Medical Accelerator Chiba, National Institute of Radiological Sciences, Chiba, Japan. Three different types of glioblastoma multiforme (GBM) cell lines were studied. Using GBM cell lines which arise from the glia cells could aid in the understanding of the effects of space radiation to the brain. Clonogenic assay was used to determine the efficacy of the radiations. Certain strains of GBM are low-dose hypersensitive and hence, the very low doses used to study space radiation here are relevant. Results show that 0.2 Gy 56Fe (500 MeV/- 200 keV/μm) ions were able to inactivate approximately 8% of T98G, 15% LN18 and 27% of U87 cells. These results may infer and demonstrate the deleterious effects of 56Fe ions on human CNS, since a significant percentage of GBM cells were killed at very low doses. The data presented may therefore be employed in assessing risk related to high LET radiation exposure, simulating the effects in space radiation.

Clinical implications of hypoxia-inducible factor-1α and caveolin-1 overexpression in isocitrate dehydrogenase-wild type glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the most common type of primary brain tumour in adults, and presents a very low survival rate. Isocitrate dehydrogenase (IDH)1/2 mutations have been found in ~12% of glioblastomas and are associated with long-term GBM survival. However, the risk factors that influence the prognosis of IDH-wild type GBM remain unclear. Hypoxia-inducible factor (HIF)-1α, an important oxygen-regulated transcription factor, has been demonstrated to serve a crucial role in tumour development and to be associated with a poor prognosis. In addition, caveolin-1 (CAV1) is a plasma membrane organizing protein, the expression of which can also be regulated by a hypoxic microenvironment. The present study therefore aimed to examine the expression levels of HIF-1α and CAV1, and their association with GBM prognosis. Reverse transcription-quantitative polymerase chain reaction and western blotting were performed to analyse the expression levels of HIF-1α and CAV1 in paired GBM tumour and adjacent non-tumour tissues. Immunohistochemistry was used to analyse the expression of the two proteins in paraffin-embedded tissues obtained from 42 patients with IDH-wild type GBM. Statistical analyses were performed to examine the correlation between HIF-1α and CAV1 expression and patient prognosis. The results revealed hat the expression levels of HIF-1α and CAV1 were upregulated in IDH-wild type GBM tissues compared to their paired non-tumour tissues (P<0.001). The expression of CAV1 was significantly correlated with high HIF-1α expression (P<0.01). In addition, overexpression of HIF-1α and CAV1 was markedly associated with a poor prognosis (P<0.001). In conclusion, HIF-1α and CAV1 may represent potential biomarkers for IDH-wild type GBM prognosis and potential targets for the development of therapies extending GBM survival.

Abstract 1318: Mapping tumoral and immune heterogeneity in PD-1 responsive glioblastoma multiforme

Abstract Background and aims: Clonal evolution and the immune microenvironment in glioblastoma multiforme (GBM) harbor critical clues to its well-known but poorly understood treatment resistance, and to assessing the potential benefit of checkpoint inhibition. We created a tumor-immune interaction map by computing the mutational and neo-epitope tumoral burden, along with the magnitude and clonality of infiltrating lymphocytes, from initial and recurrent tumor of a single patient who benefited from PD-1 blockade. The question of how this particular GBM evolution trajectory compares to a typical GBM is addressed by projection of mutational and other signatures onto a causal gene-gene interaction network we derived from the TCGA GBM cohort. Methods: We compiled samples from a 57- year-old patient who presented with a seizure and had a resection of a large temporal GBM followed by radiotherapy with concurrent temozolomide, with subsequent re-resection for recurrent disease. Starting two weeks after the final resection the patient received 26 cycles of a PD-1 checkpoint inhibitor simultaneous with 20 cycles of bevacizumab, a VEGF-A inhibitor, for a total survival of 25 months after diagnosis. Samples from the primary and three spatial sectors of the recurrence were submitted for RNA sequencing. Data analyses included intra-tumoral gene expression including MHC-I and MHC-II allele-specific expression, expressed relative mutation and (class I and class II) neo-epitope prediction, T and B cell receptor sequencing, and survival and molecular analysis on the GBM TCGA dataset. Results and Conclusions: We quantified the evolving relative mutational and neo-epitope burden of a GBM, emphasizing the differences between class I and class II neo-epitope spectra and resulting adaptive immune recruitment between the original and recurrent tumor regions. We find no evidence of hypermutation in the recurrence, a relative absence of immune infiltration in all recurrences despite the expression of a number of neo-epitope generating mutations (including a novel clonal mutation of EGFR), and compelling evidence of epigenetically driven aberrations in one recurrence sector. Hypothesizing significant molecular heterogeneity as a result of immune editing and treatment, we derived a tumor-recurrence molecular evolution trajectory and projected it onto a Bayesian inference network we derived from the TCGA GBM cohort. We quantified intra-tumoral heterogeneity, derived a patient survival signature, and also identified immunogenic mutated gene regulatory subnetworks that could be potentially targeted by any induced robust immune response. Citation Format: Bojan Losic, Raymund Yong, Nicholas Akers, Ilaria Laface, Nadejda Tsankova, Robert Sebra, Sacha Gnjatic, Adilia Hormigo. Mapping tumoral and immune heterogeneity in PD-1 responsive glioblastoma multiforme [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1318.

Abstract 2805: A panel of orthotopic glioblastoma multiforme (GBM) patient derived xenograft (PDX) mouse models for efficacy evaluation of drugs

Abstract Background: Patients with glioblastoma multiforme (GBM) have a poor prognosis and few treatment options; hence new treatments are needed. Subcutaneous patient derived xenograft (PDX) models are increasingly used for efficacy studies in drug development. However, orthotopic implantation confers a translational advantage as the cancer develops in a microenvironment more closely mimicking that of the original patient tumor. Also the major impact of the blood brain barrier that must be taking into account when targeting brain tumors as GBM in terms of drug bioavailability is better represented in the orthotopic models. The aim of this study was therefore to develop a panel of orthotopic GBM PDX models for pre-clinical efficacy studies of new drugs. The models were then used to study the efficacy of standard of care such as temozolomide (TMZ) and external radiation therapy (XRT). Methods: Low passage subcutaneous tumors from six different PDX GBM models designated ST108, ST112, ST146, ST545, ST610 and ST2473 were digested and used for intracranial stereotactic injection in nude mice. Tumor take and growth was determined by T2-weighted magnetic resonance imaging (MRI). At confirmed tumor take mice were either treated with TMZ (100mg/kg/day for 5 days) or whole brain XRT (2 Gy/day for 5 days). Control groups receiving vehicle or sham XRT were included depending on treatment regiment. Final endpoint was survival by humane endpoints and tumors were fixed in formalin for histological evaluation. Results: MRI confirmed tumor take in all models within 5 weeks of implantation. The take rate was &amp;gt; 80% across all models. TMZ showed efficacy in the orthotopic ST610 GBM PDX model evaluated by MRI on day 14 (16.2±2.9 mm3 vs. 76.8±13.1 mm3, p=0.016), whereas the ST146 model displayed resistance to TMZ on day 14 (12.7±5.6 mm3 vs. 26.5±11.9 mm3, p=0.26). The median survival was 60 days vs. 14 days in the ST610 model (TMZ vs. vehicle, p=0.0005) and 27 days vs. 13 days in the ST146 model (TMZ vs. vehicle, p=0.007). XRT showed efficacy in the orthotopic ST2473 model. Tumor volume was significantly smaller in treated vs. sham animals 11 days after inclusion (6.9±1.4 mm3 vs. 28.9±3.3 mm3, p=0.001). Also, a survival benefit was observed in XRT treated animals compared to sham. Histology confirmed the presence of orthotopic tumors and typical GBM pathology characteristics such as pseudopalisading tumor cells surrounding necrosis and micro vascular proliferation were identified. Conclusion: Six different orthotopic GBM PDX models were established from low passage subcutaneous PDX models. Models sensitive and resistant to TMZ were identified and histological GBM characteristics were identified. Together, the established panel of orthotopic PDX models can be used as a relevant translational platform for testing of new drugs in a setting that more closely mimics the GBM tumor microenvironment and the impact of the blood brain barrier in patients. Citation Format: Mette M. Jensen, Camilla S. Knudsen, Lotte K. Kristensen, Mette K. Nedergaard, Michael J. Wick, Kyriakos P. Papadopoulos, Anthony W. Tolcher, Andreas Kjaer, Carsten H. Nielsen. A panel of orthotopic glioblastoma multiforme (GBM) patient derived xenograft (PDX) mouse models for efficacy evaluation of drugs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2805. doi:10.1158/1538-7445.AM2017-2805

Designing the angiogenic inhibitor for brain tumor via disruption of VEGF and IL17A expression

Glioblastoma multiforme is a highly malignant, heterogenic, and drug resistant tumor. The blood–brain barrier (BBB), systemic cytotoxicity, and limited specificity are the main obstacles in designing brain tumor drugs. In this study a computational approach was used to design brain tumor drugs that could downregulate VEGF and IL17A in glioblastoma multiforme type four. Computational screening tools were used to evaluate potential candidates for antiangiogenic activity, target binding, BBB permeability, and ADME physicochemical properties. Additionally, in vitro cytotoxicity, migration, invasion, tube formation, apoptosis, ROS and ELISA assays were conducted for molecule 6 that was deemed most likely to succeed. The efflux ratio of membrane permeability and calculated docking scores of permeability to glycoproteins (P-gps) were used to determine the BBB permeability of the molecules. The results showed BBB permeation for molecule 6, with the predicted efficiency of 0.55kcal/mol and binding affinity of −37kj/mol corresponding to an experimental efflux ratio of 0.625 and predicted −15kj/mol of binding affinity for P-gps. Molecule 6 significantly affected the angiogenesis pathways by 2-fold downregulation of IL17A and VEGF through inactivation of active sites of HSP90 (predicted binding: −37kj/mol, predicted efficiency: 0.55kcal/mol) and p23 (predicted binding: 12kj/mol, predicted efficiency: 0.17kcal/mol) chaperon proteins. Additionally, molecule 6 activated the 17.38% relative fold of ROS level at 18.3μg/mL and upregulated the caspase which lead the potential synergistic apoptosis through the antiangiogenic activity of molecule 6 and thereby the highly efficacious anticancer upshot. The results indicate that the binding of the molecules to the therapeutic target is not essential to produce a lethal effect on cancer cells of the brain and that antiangiogenic efficiency is much more important.

Abstract 4148: Different immune cell responses are associated with glioblastoma subclassification and typical genetic alterations

Abstract Interactions between various components in the tumor microenvironment and dysregulated immune responses are thought to play important roles in cancer development. To better understand the role of immune cells in tumor pathogenesis and destruction, we computationally model the microenvironment of an aggressive brain tumor glioblastoma multiforme (GBM). We downloaded GBM patient RNA-seq data from the Cancer Genome Atlas (TCGA). Using cluster analysis, we identified 16 clusters, each containing 10 to 933 genes that show a statistical enrichment of immune response related gene ontology terms. Utilizing a panel of RNA-seq data from normal cell types, we constructed global and cluster specific regression models to characterize the expression profiles of GBM samples in the clusters of interest as linear combinations of normal cell and reference GBM expression profiles. Simulated data was used to validate that the regression model coefficients accurately reflect the contributions of normal cell types to the expression profiles of tumor samples. Based on the regression analysis, we were able to uncover high variability in the composition of microenvironment across the TCGA cohort, suggesting diverse immune responses in tumors. The results from global regression analysis were then associated with common genetic alterations in GBM and with GBM subclassification. Especially the estimated macrophage, granulocyte, and CD8+ T lymphocyte proportions show significant differences between different GBM subgroups. Accumulation of immune cells was increased in the mesenchymal and neural subtype compared to other subtypes. Furthermore, estimated immune cell proportions were associated with alterations in EGFR and NF1. Taken together, our analysis provided a characterization of the immunomicroenvironment in GBM and linked immune cell responses to typical GBM alterations and GBM subtypes. More detailed characterization of diverse immune responses will facilitate patient stratification and might provide tools for personalized immunotherapy in the future. Citation Format: Suvi Luoto, Juha Kesseli, Matti Nykter, Kirsi J. Granberg. Different immune cell responses are associated with glioblastoma subclassification and typical genetic alterations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4148.

CBIO-46SPINDLE CELLS IN EARLY C6-GBM GROWTH ARE STEM CELLS - FUNCTIONAL STUDY WITH MITOCHONDRIAL VOLUME FOR THERAPEUTIC PURPOSE

OBJECTIVE: Recurrence of glioblastoma multiforme (GBM) after total resection is postulated to originate from precursor cells existing in surrounding brain tissue. The authors have found spindle cells in the early stage of rat C6 GBM growth, resembling spongioblasts, the origin of GBM (Bailey and Cushing, 1926). They are stem-like cells with positive CD15 staining, and should be the primary target for treatment in experimental animals (Poster at SPNO meeting in May). Currently, spindle cells are functionally evaluated by mitochondrial volume studies for future development of therapeutic tactics. METHODS: 1. C6 cells were cultured in MEM solution, and morphological cell changes were studied with and without temozolomide (TMZ) treatment. 2. Mitochondrial volume of C6 cell in these conditions was measured by mitochondrial mass specific fluorescence probe. 3. C6 cells were implanted into rat's brain and observed the growth in the normal brain tissue. RESULTS: 1. Spindle cells grew in early period, and formed syncytiums. As syncytiums multiplied, mitotic cells began to appear, and typical GBM features developed. During TMZ treatment, multiform cells were mostly destroyed, while spindle cells survived. 2. By TMZ treatment, the number of survived C6 cells decreased, but the volume of mitochondria per unit of C6 cells increased, as the concentration of TMZ increased. 3. The same cell growth pattern was identified in implanted tumor, as seen in cultured cells growth. DISCUSSION AND CONCLUSION: 1. Histologically CD15-positive spindle cells have much higher resistance for survival against TMZ than fully developed multiform cells. 2. Increased mitochondrial volume in survived C6 cells is likely related to metabolic activation of spindle cells under TMZ treatment. 3. The control of mitochondrial hyperactivity of C6 cells should be one of the important means for GBM treatment in experimental GBM, and probably in humans.

Infratentorial Glioblastoma Multiforme in a Young Patient

Glioblastoma multiforme (GBM) is the most common primary supratentorial tumor of the brain. Infratentorial type GBM is very rare especially in young patients. In this report we present a case of primary infratentorial GBM in a young patient which was treated surgically with concomitant chemoradiotherapy.

Awareness about Glioblastoma

Glioblastoma or glioblastoma multiforme abbreviated as GBM is the most common and most aggressive type of glioma. Glioblastoma tumors arise from astrocytes (star shaped cell) that make glue like tissues of the brain. Astrocytomas are a type of cancer of the brain and GBM is grade four tumors & the most malignant form of astrocytoma. Our survey aimed to find out its awareness among the pharmacy undergraduates at Jinnah University for Women, Karachi, Pakistan. A random and cross-sectional method was to collect the data in the month of May- June, 2014. After our survey we have concluded that the awareness of glioblastoma multiforme is very less in pharmacy undergraduates. There were only 12% students who know about the glioblastoma multiforme. There were only 3% students who know about the treatment of glioblastoma multiforme, whereas only 2% pharmacy undergraduates who knows the types of glioblastoma multiforme, difference between primary and secondary type of glioblastoma multiforme and the causes of glioblastoma multiforme. This result shows that almost there is no awareness about the grade 4 tumor, glioblastoma multiforme.

Multiple Microsurgical Resections for Repeated Recurrence of Glioblastoma Multiforme

There has been little evidence so far supporting further surgical intervention in case of repeated recurrence of glioblastoma multiforme (GBM). Thus, the efficacy and utility of repeated resection remains unclear but worthy of consideration. The aim of this study was to review the efficacy of multiple repeated resections in patients with recurrent GBM. Forty-two patients underwent repeated surgical resections for recurrent GBM. All patients who underwent >2 surgical interventions were clustered in group A. Group B were patients treated nonsurgically after resection of the first recurrence. Patients' treatment history, including surgical interventions, radiotherapy, chemotherapy regimens, postoperative complications, Karnofsky Performance Score, and survival rate were reviewed. Group A consisted of 10 patients (median age, 60.5 y) and group B of 32 patients (median age, 56.5 y). Histopathologic findings revealed typical GBM in 8 patients of group A and in 23 patients of group B. An oligodendroglial component was detected in 2 patients of group A and in 7 patients of group B. The median Karnofsky Performance Score after the first surgery for tumor recurrence was 80 in both groups (P=0.084). The median overall survival time was 26 months in patients of group A and 16 months in patients of group B (P=0.052). The 2-year survival rate of group A was 58.3% and significantly higher than in group B (29.0%; P=0.036). The 3-year survival rate of group A was 31.1% and 12.4% of group B (P=0.038). Microsurgical resection of repeatedly recurring GBM is likely to prolong survival. Repeated surgical resection may be considered as an effective treatment option in addition to radiochemotherapy in repeated GBM recurrence.

Evaluation of Tyrosine Kinase Inhibitor Combinations for Glioblastoma Therapy

Glioblastoma multiforme (GBM) is the most common intracranial cancer but despite recent advances in therapy the overall survival remains about 20 months. Whole genome exon sequencing studies implicate mutations in the receptor tyrosine kinase pathways (RTK) for driving tumor growth in over 80% of GBMs. In spite of various RTKs being mutated or altered in the majority of GBMs, clinical studies have not been able to demonstrate efficacy of molecular targeted therapies using tyrosine kinase inhibitors in GBMs. Activation of multiple downstream signaling pathways has been implicated as a possible means by which inhibition of a single RTK has been ineffective in GBM. In this study, we sought a combination of approved drugs that would inhibit in vitro and in vivo growth of GBM oncospheres. A combination consisting of gefitinib and sunitinib acted synergistically in inhibiting growth of GBM oncospheres in vitro. Sunitinib was the only RTK inhibitor that could induce apoptosis in GBM cells. However, the in vivo efficacy testing of the gefitinib and sunitinib combination in an EGFR amplified/ PTEN wild type GBM xenograft model revealed that gefitinib alone could significantly improve survival in animals whereas sunitinib did not show any survival benefit. Subsequent testing of the same drug combination in a different syngeneic glioma model that lacked EGFR amplification but was more susceptible to sunitinib in vitro demonstrated no survival benefit when treated with gefitinib or sunitinib or the gefitinib and sunitinib combination. Although a modest survival benefit was obtained in one of two animal models with EGFR amplification due to gefitinib alone, the addition of sunitinib, to test our best in vitro combination therapy, did not translate to any additional in vivo benefit. Improved targeted therapies, with drug properties favorable to intracranial tumors, are likely required to form effective drug combinations for GBM.

Magnetic Resonance Imaging and Computed Tomography Findings in Pediatric Giant Cell Glioblastoma

Giant cell glioblastoma (GCG) is considered to be a subtype of glioblastoma multiforme (GBM). This malignant tumor of glial origin is a grade IV tumor according to the current classification of the World Health organization (WHo, [1]) and accounts for approximately 5% of GBMs and 0.8% of all brain tumors [2]. In pediatric patients supratentorial tumors are less common than infratentorial tumors with a ratio of approximately 1:2. The GBMs account for 7–9% of all intracranial tumors and 0.6–7.9% of all GBMs occur during childhood [3]. These statistics demonstrate that GCG is an exceedingly rare tumor mainly described in isolated case reports or series with a predilection for younger patients [2, 4]. The GCGs arise from white matter, as do the common GBMs and have a tendency to involve the frontal and temporal lobes [2, 5]. The higher predilection for the cerebral hemispheres than a typical GBM, probably in addition to histological variations, may be responsible for the better prognosis as the location means that gross total resection is more frequent. The tumor is macroscopically well-circumscribed and histologically shows numerous bizarre multinucleated giant cells with an abundant reticulin network and a high frequency of p53 mutations [6, 7]. In general terms GBM has a poor prognosis with a mean survival time ranging from 12–15 months in adults [8]. In pediatric patients with high grade astrocytoma the outcome is slightly better but still remains poor with survival times ranging from 15–42 months [9, 10]. In standard GBM treatment protocols tumor resection is followed by irradiation and dnA alkylating chemotherapy. Adding temozolomide as a chemotherapy drug significantly improved outcome in newly diagnosed GBM [11, 12] and the median survival time improved from 12.1 to 14.6 months and the 2-year survival rate reached 25.6% compared to 10.4% previously when adding temozolomide to standard GBM treatment protocols [13, 14]. other factors associated with decreased survival in GBM include but are not limited to larger tumor size [15], higher age [16] as well as bilateral location [17]. The GCG is associated with longer survival times compared to GBM, ranging from 15 months up to 17 years in adults [5, 18] and ranging from 14 months up to 12 years in children [4, 19].one case report also reported a long-term survival with a late transformation to gliosarcoma [6].

Primary Extracerebral Meningeal Glioblastoma: Clinical and Pathological Analysis

Primary meningeal gliomas are uncommon tumors in the subarachnoid space, their primary characteristic being the absence of any obvious connection to the brain parenchyma. Rarely, they are quite malignant and assume a bulky, well circumscribed appearance rendering the differential diagnosis from other CNS neoplasms difficult. A 53-year-old man presented with a history of persistent headaches and left sided weakness. Magnetic resonance imaging revealed a temporoparietal mass attached to the dura that strongly resembled a meningioma. At surgery, the outer layer of the dura mater was intact and there was a clear brain-tumor interface without obvious pial disruption. Histological examination showed a biphasic pattern consisting of benign connective tissue intermingled with bundles of what seemed to be a glioblastoma. The mass demonstrated strong positivity for GFAP and the MIB labeling index focally exceeded 20%. The tumor was identified as a primary meningeal glioblastoma. The patient was disease-free for 42 months, after which he developed a recurrence for which he was re-operated. This time, the pathological findings of the tumor were those of a typical glioblastoma multiforme. We discuss the origin of the initial neoplasm and also the differential diagnosis that needs to include meningioma, aggressive glioblastoma infiltrating the dura and a recently recognized bimorphic CNS tumor: the desmoplastic glioblastoma.