bluuebunny/crossref_metadata_2025 huggingface dataset:
BIOM-07. LOW EXPRESSION OF HLA-A AS A NOVEL PROGNOSTIC FACTOR IN GLIOBLASTOMA TREATED WITH TUMOR FUSED DENDRITIC CELL VACCINES
Authors: Takei Jun , Akasaki Yasuharu , Tanaka Toshihide , Fukasawa Nei , Gomisawa Kazutaka , Satake Mari , Mori Ryosuke , Yamamoto Yohei , Oda Ayaka , Kamata Yuko , Murahashi Mutsunori , Fukuda Takahiro , Shimoda Masayuki , Murayama Yuichi
Published: November 2022

Although immunotherapy has become an attractive approach to cancer treatment in patients with broad types of aggressive tumors, phase III clinical trials of immunotherapy for glioblastoma (GBM) have not achieved extended survival of patients. Dendritic cells perform an essential role in the immune system as antigen-presenting cells and tumor fused dendritic cells (TFDCs) can induce tumor-specific cytotoxic T cells as a cancer vaccine. We have previously described the safety and mechanisms of TFDCs therapy, as well as immunological and clinical responses of patients with GBM, however, there were little known about predictive and prognostic biomarkers specific to TFDCs therapy. In the present study, we investigated the whole transcriptome sequencing of tumor cells, and novel prognostic factors were identified through molecular profiling GBM treated with TFDCs immunotherapy. Fifty-three patients were eligible in this study and 28 samples from patients with newly diagnosed GBM IDH wild-type were included. Of these 28 samples, 15 high-quality RNA samples successfully extracted from tumors were analysed. The samples were divided into two groups based on the median patient's overall survival. Differential expression analyses and enrichment analysis between the two groups were carried out using CLC Genomics Workbench (QIAGEN), and Gene Ontologies (GO) were assigned. A total of 473 differentially expressed genes were detected including 327 enriched GO terms. Fifteen GO terms out of 327 GO terms represented the highest enrichment scores, revealed that five GO terms were associated with the major histocompatibility complex (MHC). The relationship among the MHC, immune-related genes, and clinical outcomes was investigated using the Cox regression model and Kaplan–Meier log-rank test. Low expression of HLA-A in the tumors turned out to be a significantly favorable prognostic impact (p = 0.01). The decreased expression of HLA-A might be a novel prognostic factor in GBM patients treated with TFDCs immunotherapy.
BIOM-08. IL13RA2 AS A LIQUID BIOPSY BIOMARKER FOR NERVOUS SYSTEM TUMORS
Authors: Khristov Vladimir , Nesterova Darya , Patel Neel , Smith Nataliya , Shenoy Ganesh , Zacharia Brad , Harbaugh Kimberly , Rizk Elias , Connor James
Published: November 2022

While tumors of the nervous system (NS) are rare, they contribute to significant morbidity and mortality. Despite advances in imaging technology, initial diagnosis and characterization of treatment response remains problematic for devastating tumors such as glioblastoma (GBM). A liquid biopsy can provide a minimally-invasive and serial source of biomarkers to supplement current diagnostic methods. Here, we utilize a unique characteristic of NS tumors including GBM and schwannoma/neurofibroma – the overexpression of the a2 variant of the IL-13 receptor which is not detectable in normal tissue. Previously, we have shown that IL13Ra2 is elevated in the plasma of some GBM patients above baseline levels. We hypothesize that the presence of circulating IL13Ra2 not only predicts the level of this receptor in the tumor tissue, but also has clinical prognostic value. Here, we used ELISA to measure the plasma levels of IL13Ra2 in the GBM (n=77) and schwannoma/neurofibroma (n=15) patients and correlated these levels to tumor levels, diagnosis, and clinical characteristics. We have demonstrated that elevated levels of plasma IL13Ra2 correlated with tumor presence compared to non-tumor controls for both GBM and schwannoma/neurofibroma patients, indicating this biomarker’s diagnostic utility. Further, for both GBM and schwannoma/neurofibroma patients the plasma concentration of IL13Ra2 is correlated to its tumor concentration, indicating that sampling patient plasma could provide insight into the tumor’s composition. Finally, elevated levels of IL13Ra2 protein in the tumor and plasma of GBM patients predicted longer patient survival. These exciting findings lay the groundwork for a plasma-based NS tumor liquid biopsy.
BIOM-09. GUIDING PRECISION THERAPEUTICS THROUGH INTERROGATING ONCOGENIC PATHWAY ACTIVATION
Authors: Nobre Liana , Levine Adrian , Milos Scott , Johnson Monique , Laxer Ben , Ryall Scott , Bennett Julie , Ku Michelle , Siddaway Robert , Tabori Uri , Hawkins Cynthia
Published: November 2022

The deregulation of canonical oncogenic pathways are largely responsible for driving pediatric cancers and can be targeted for therapeutics. Currently, we interrogate these pathways clinically by looking for gene mutations, but these are not found in all cases, and in others multiple genes are. We hypothesized that assessing transcriptomic and proteomic-based pathway activation will allow a better understanding of the most active oncogenic pathways and help guide therapy. To do this, we developed and validated a nanostring based assay that interrogates 4 key actionable pathways (MAPK, PI3K-AKT-mTOR, JAK-STAT, and NFkB) including RNA, protein and phosphoprotein expression. The assay was clinically validated using isogenic cell lines and a cohort of 40 gliomas with previous RNAseq. We then interrogated over 400 tumor samples, including 15 ependymomas, 11 medulloblastomas, 250 low grade gliomas (LGG), 145 high grade gliomas and 10 control normal brain specimens. Interestingly, although pediatric LGG exhibited higher MAPK activation than control tissue and other tumor types, a subset of these tumors have increased activity in PI3K , JAK and NFKB pathways. Furthermore, high PI3K activation score was correlated with worse PFS in a subset of pediatric LGGs that required adjuvant chemotherapy (p=0.018). To further explore the therapeutic implication of the assay, we analyzed a cohort of patients treated with MEK inhibitors (n=20). Strikingly, on top of universal RAS/MAPK activation, crosstalk between additional activated pathways such as PI3K and JAK-STAT may contribute to lack of response. In particular, pre-treatment and post-progression PLGG who failed therapy, revealed mild reduction in MAPK signature accompanied by increased PI3K phospho-proteins (p-S6/p-4EBP1,p-AKT)(p< 0.01). We conclude that assessing oncogenic pathway activation can add to DNA sequencing to predict different outcome and response to targeted therapies in childhood brain tumors. This can inform future therapeutic strategies including the identification of potential responders and combination strategies for non-responders.
BIOM-19. NEXT-GENERATION SEQUENCING (NGS) FOR IDENTIFYING ACTIONABLE MOLECULAR ALTERATIONS IN NEWLY DIAGNOSED AND RECURRENT IDHWT-GLIOBLASTOMA (GBM) PATIENTS: A LARGE MONO INSTITUTIONAL EXPERIENCE
Authors: Padovan Marta , Maccari Marta , Bosio Alberto , Vizzaccaro Salvatore , Cestonaro Ilaria , Corrà Martina , Caccese Mario , Cerretti Giulia , Fassan Matteo , Zagonel Vittorina , Lombardi Giuseppe
Published: November 2022

BACKGROUNDNGS

panels allow the identification of alterations within hundreds of cancer-related genes and can guide a personalized strategy in glioma treatment.

METHODS

From Nov 2019 to Jan 2022 at Veneto Institute of Oncology, Padua, Italy, a large cohort of IDHwt-GBM tissues was analyzed by NGS (FoundationOne®CDx). We identified all potential actionable molecular alterations at diagnosis and/or at recurrence. High tumor mutational burden (TMB) was defined as ≥10 mutations/megabase.

RESULTS

We analyzed 429 IDHwt-GBM samples: NGS profile was available for 419 samples (97.7%); sample failures in 10 cases (2.3%). 351 (84%) and 68 (16%) GBM samples derived from surgery at diagnosis and recurrence, respectively. All patients received radiotherapy and/or temozolomide as first line therapy. Among all the analyzed samples, the most frequent actionable molecular alterations were: CDKN2A (57%), CDKN2B (53%), EGFR amplification (39%), EGFR mutation (24%), PTEN loss (27%), RB1 (23%), NF1 (18%), PIK3CA (18%), CDK4 (15%), MDM2 (10%), PDGFRA (8%), BRCA1-2 (7%), FGFR1-3 (7%), Myc (6%), JAK (6%), ROS1 (5%), METmut (2%), METampl (2%), BRAF V600E (2%). No NTRK1/2/3 druggable alterations were observed. High TMB was found in 18 samples. The incidence of alteration of EGFR (ampl/mut), RB1, PIK3CA was statistically different between the two subgroups of newly diagnosed and recurrent GBM samples (Fisher test). To date, 10% of patients received a personalized treatment as compassionate use, off-label use or in clinical trials (9 Dabrafenib/Trametinib, 8 Alpelisib, 3 Erdafitinib, 2 Ipatasertib, 1 Alectinib, 1 Capmatinib, 1 Palbociclib, 1 Entrectinib, 1 Pamiparib). Activity analysis is still ongoing.

CONCLUSIONNGS

is feasible in GBM samples. Potentially, a high rate of patients could receive a personalized treatment. The activity analysis is ongoing. However, the incidence of actionable molecular alterations may differ between diagnosis and recurrent GBM samples.
BIOM-20. IDENTIFICATION OF BLOOD BIOMARKERS FOR DIFFERENTIATING PSEUDOPROGRESSION FROM RECURRENCE IN GLIOBLASTOMA
Authors: Nakada Mitsutoshi , Ohtsuki Sumio , Uchida Yasuo , Nakajima Riho , Sabit Hemragul , Tamai Sho , Ichinose Toshiya , Kinoshita Masashi ,   team BIRD-DOG
Published: November 2022

After the initial treatment of glioblastoma, we occasionally encounter difficulty in distinguishing between pseudoprogression and recurrence. Observation without obtaining a pathological diagnosis is a common strategy in clinical practice. If the differentiation can be achieved easily, and reliably, early treatment can be introduced appropriately, leading to the benefits of early glioblastoma treatment. In this study, we attempted to identify blood biomarkers that help distinguish between recurrence and pseudoprogression. Blood samples were collected in 25 cases of primary glioblastoma, IDH wild type, at three time points: before treatment, after standard treatment: operation and temozolomide chemotherapy with concomitant radiation therapy, and when an enhancing lesion was recognized (21 cases of recurrence, 4 cases of pseudoprogression). Gelsolin (GSN), Apolipoprotein A-IV, Osteopontin, SERPINA3, ITIH2/4 Ceruloplasmin, LRG1, Collagen-1A2, which we previously extracted as diagnostic markers, using the comprehensive proteomics SWATH method, in blood samples of healthy volunteers and patients with glioblastoma (PLoS One. 2018, J Proteome Res. 2020), were analyzed. Absolute quantitative values of candidate molecules in the blood were obtained using a commercially available enzyme-linked immunoassay. Among the candidate molecules, GSN was significantly lower in pseudoprogression than in recurrence (p = 0.0032), and ROC analysis showed sensitivity of 95%, specificity of 100%, and an AUC = 0.98, which makes GSN a useful molecule to consider as a differential marker. We previously reported that GSN, actin binding protein, and inflammation markers are downregulated in glioblastoma (Cancer Sci. 2020). In summary, GSN was extracted as a candidate blood biomarker for the diagnosis of pseudoprogression. We are planning to validate the research with nationwide multi-institutional studies.
BIOM-28. AN EXOSOME BASED LIQUID BIOPSY DIAGNOSTIC FOR GLIOMA
Authors: Ray Amit , Lath Rahul , Reddy Madhan , Ippili Kaushal , Ratnam Boola , Vohra Tarang , Reddy Arjun , Prasad Brahma , Ranjan Alok , Reddy Rajesh , Panigrahi Manas , Rao Venkateshwara , Balasubramanium Anandh , Kaur Inderjeet
Published: November 2022

BACKGROUND

Liquid biopsy has gained popularity of late in the diagnosis and management of several cancers. This study aims to diagnose suspected lesions suspected of being gliomas on neuro-imaging by obtaining a peripheral venous blood sample- with a specificity and sensitivity that approaches a tissue biopsy. MATERIALS AND

METHODS

After clearance from Ethics Committees, specimens of the tumour tissue along with blood from a peripheral or vein was collected from all 80 adult patients with a suspected diagnosis of glioma. Clinical details along with the neurological status, the functional score, the extent of resection, pathological diagnosis and survival data were also collected. The tumour tissue transported in RNA-later and stored at -80C. Following exosome isolation, RNA-seq was performed on the exosomal sample obtained from the serum and the tumour sample. Exome analysis was performed on the tumour tissue (somatic mutations) and the WBC (for germline mutations) to a depth of 100.

RESULTS

The analysed data was quality checked for all glioma associated genes including but not limited to ATRX, H3F3A, IDH1, MGTM and TERT driver genes related to DNA repair, cytoskeleton and cellular proliferation-related genes EGFR, FLT1/(VEGFR), BRAF, GFAP, MKi67, NES, OLIG2, PIK3CA, SMAD3, S1001A and VIM and tumour suppressor genes SMARCB1/INI1 and TP53. Open-source cloud based genomic analysis platforms were used for analysis. Machine learning clustering algorithms identified serum exosome based clusters that corresponded to already identified glioma tissue based genomic subgroups, with specificity and sensitivity approaching 95%.

CONCLUSION

Liquid biopsies provide a reliable and effective way of diagnosing gliomas in patients who present with an intracranial lesion on radiology.
BIOM-33. TEMPORAL HETEROGENEITY OF DNA METHYLATION SUBCLASSES BETWEEN MATCHED NEWLY DIAGNOSED AND RECURRENT IDH-WILDTYPE GLIOBLASTOMA
Authors: Drexler Richard , Schüller Ulrich , Eckhardt Alicia , Sauvigny Thomas , Ricklefs Tammo , Bode Helena , Khatri Robin , Hausmann Fabian , Hänzelmann Sonja , Huber Tobias , Bonn Stefan , Lamszus Katrin , Westphal Manfred , Dührsen Lasse , Ricklefs Franz
Published: November 2022

Spatiotemporal heterogeneity is a major factor contributing to the devastating prognosis of isocitrate-dehydrogenase (IDH)-wildtype glioblastoma. Genome-wide DNA methylation profiling allows the stratification into several DNA methylation subgroups of IDH-wildtype glioblastoma, which were shown to have a spatial heterogeneity in newly diagnosed tumors. However, the temporal heterogeneity and its clinical relevance of DNA methylation subgroups remains inconclusive. Tumor tissue obtained from first and recurrence surgery of 31 patients diagnosed with IDH-wildtype glioblastoma was subjected to DNA methylation profiling. DNA methylation profiles were analyzed for temporal heterogeneity and correlated with clinical data, survival outcome and copy number variations. In addition, deconvolution of immune cells and unsupervised hierarchical clustering using pairwise Pearson correlation coefficients of the 10.000 most variable CpG features was performed. Of all patients with matched tumor tissue, 4 (12.9%) patients had a non-matching brain tumor classifier output at recurrence. Within the remaining 27 patients, a transition of the dominant DNA methylation subclass was observed in 8 (29.6%) glioblastomas with a most frequent transition to the mesenchymal subclass (62.5%). A subclass transition was more likely after incomplete removal of contrast-enhanced tumor parts at first surgery (p = 0.04). Tumor location, adjuvant treatment, and time between primary and recurrence surgery did not influence the transition. Immune cell proportions from deconvolution data, tumor purity or specific CpG sites were not correlated with a subclass transition. Survival analyses revealed a comparable outcome for patients with or without subclass transition. Our findings demonstrate the temporal heterogeneity of DNA methylation subclasses in 29.6% of IDH-wildtype glioblastoma. We identified clinical factors and showed that a subclass transition did not impact the survival outcome. However, a possible DNA methylation subclass transition must be taken into consideration for future targeted therapies at recurrence.
BIOM-40. COMPARATIVE STUDY OF INFLAMMATORY MARKERS IN THE CEREBROSPINAL FLUID OF PATIENTS WITH GLIOMA AND CENTRAL NERVOUS SYSTEM MALIGNANT LYMPHOMA
Authors: Sasayama Takashi , Tanaka Kazuhiro , Nagashima Hiroaki , Fujita Yuichi , Iwahashi Hirofumi , Kodama Yoshinori , Nishihara Masamitsu
Published: November 2022

INTRODUCTION

Cytokines in the cerebrospinal fluid (CSF) are useful as markers for primary central nervous system malignant lymphoma (PCBSL). However, there are few reports of CSF markers in glioma. We analyzed and examined glioma and PCNSL CSF inflammation-related mediators.

MATERIALS AND METHODS

The patients with glioma and PCNSL who were operated on at Kobe University between 2006 and 2017 and whose histology was diagnosed, and whose CSF was stored at -80 °C before treatment. Using Bio-Plex Pro Human Inflammation Assays (Bio-Rad Laboratories, Inc.), 37 types of inflammation-related molecules such as TNF superfamilies, interferonss, and Interleukines were measured and compared with glioma and PCNSL.

RESULTS

The subjects were 53 glioma patients and 24 PCNSL patients. There were 22 types of significant differences between glioma and PCNSL, 18 with high PCNSL and 4 with high glioma. In addition to IL-10, which has been reported so far, the significant higher concentrations in PCNSL was found in Osteopontin, TNFSF8, TNFSF12, TNFSF13, TNFSF13B, TNFSF14, sTNF-R1, sTNF-R2, IL-6Ra, IL-8, IL-12(p40), IL-20, IL-27, sCD163, MMP2, MMP3, CHI3L1. On the other hand, IL-2, Il-12(p70), IL-22, and MMP-1 levels were significant higher in CSF in glioma. Although CD163 is an important molecule as a marker for M2 macrophages, immunostaining of tissues showed no significant difference in infiltration between Glioblastoma and PCNSL. This suggests that M2 macrophages infiltrating PCNSL and Glioblastoma have different activation states.

CONCLUSION

PCNSL had higher levels of inflammatory mediators such as TNF-related molecules. PCNSL was significantly higher in sCD163 than in glioblastoma, suggesting different activation of intratumoral M2 macrophages.
BIOM-41. IDENTIFICATION OF GLIOMA CELLS BY PROFILING SINGLE-CELL BIOPHYSICAL PROPERTIES THROUGH MULTICONSTRICTION MICROFLUIDIC CHANNELS
Authors: Ren Xiang , Ji Hongming , Geng Xin
Published: November 2022

This study introduces a multicontraction microfluidic channel that can differentiate glioma cells from normal glio cells. As cells pass through successive constriction channels, the incremental velocity and varying size profiles of the cells will be collected, reflecting their biophysical properties. The data of high-dimensional variables were analyzed , including the cell sizes, velocities, and velocity increments. The prediction value is used to represent the difference between two groups using the established classification model from high-dimensional variables. At the same time, we prepared three groups of primary tumor cells from patients with different grades of glioma to verify the efficacy of this classification method. The results show that in this microfluidic channel, the diagnostic model made of cell biophysical properties can well identify glioma cells, which gives a novel method for efficient identification of circulating tumor cells and rapid pathological diagnosis.
BIOM-49. A PILOT STUDY OF CEREBROSPINAL FLUID EXOSOMAL SMALL RNA-SEQUENCING IN PEDIATRIC MEDULLOBLASTOMA PATIENTS ON THE NEXT CONSORTIUM “HEAD START” 4 PROTOCOL
Authors: Bell Erica , Webb Amy , Stanek Joseph , Blue Megan , Patel Parth , Thomas Diana , Pierson Christopher , Mladkova Nikol , Fleming Jessica , Miller Katherine , Grischow Olivia , Liszkay Thomas , Olshefski Randall , Chi Susan , Comito Melanie , Friedman Gregory , Bendel Anne , Coven Scott , Hastings Caroline , Sayour Elias , Garvin James , Davidson Tom , Cornelius Albert , Moertel Christopher , Mazewski Claire , Walter Andrew , Greiner Robert , Puccetti Diane , Gorsi Hamza , Dorris Kathleen , Khatib Ziad , Chakravarti Arnab , Cottrell Catherine , Asgharzadeh Shahab , Huang Annie , Rassekh Rod , Limbrick David , Boue Daniel , Biegel Jaclyn , Mardis Elaine , Dhall Girish , Finlay Jonathan , Leonard Jeffrey
Published: November 2022

BACKGROUND

Head Start 4 is a randomized clinical trial to determine whether dose-intensive tandem consolidation, compared with a single cycle, with autologous hematopoietic progenitor cell rescue provides a survival benefit in pediatric patients with medulloblastoma or other embryonal tumors. The trial incorporates upfront molecular subgrouping and non-mandatory, prospective blood and cerebrospinal fluid (CSF) collection. This pilot study aimed to identify exosomal non-coding RNAs (exo-ncRNAs) that might serve as novel diagnostic and/or treatment response biomarkers.

METHODS

CSF(1-2mLs) from 11 controls (non-tumor) and 27 medulloblastoma participants including 23 obtained at baseline, 22 at the end of induction, 3 post-consolidation, and 4 relapse time points, were profiled. Exosome isolation and small RNA-sequencing were performed by System Biosciences. Differential gene expression (DGE) was performed in R (DESeq2). Variations in gene expression profiles between samples were visualized using principal component analysis.

RESULTS

After limiting to ncRNAs with expression of 2 counts per million in 50% or more of the samples in each comparison, ~9,500 ncRNAs were detected. DGE analyses revealed 118 ncRNAs with log2 fold change(FC) >2 and 1 ncRNA with log2FC< -2 in baseline CSF samples compared to controls. In contrast, 11 ncRNAs(log2FC >2) and 1 ncRNA(log2FC< -2) were detected in end of induction CSF samples compared to controls. Comparing end of induction to baseline CSF samples accounting for paired samples, 0 ncRNAs(log2FC >2) and 52 ncRNAs(log2FC< -2) were detected.

CONCLUSIONS

Overall, our data indicate that exosomal small RNA-sequencing of limited CSF volumes is feasible. Differential expression and distinct clustering between tumor baseline samples compared to non-tumor controls was observed. CSF-derived exo-ncRNAs at end of induction also demonstrated “normalization” of ncRNA profiles, signifying CSF biomarkers may serve a role in diagnosis and molecular response assessment. A comprehensive analysis including multi-marker predictive model development and molecular subgrouping will be undertaken at completion of study enrollment.
BIOM-57. DISSECTING STEMNESS IN AGGRESSIVE MENINGIOMAS: PROGNOSTIC ROLE OF SOX2 EXPRESSION
Authors: Bonaventura Rina Di , Martini Maurizio , Cenci Tonia , Caccavella Valerio Maria , Barresi Valeria , Gessi Marco , Albanese Alessio , Lauretti Liverana , Pallini Roberto , D'Alessandris Quintino Giorgio , Olivi Alessandro
Published: November 2022

Aggressive meningiomas are prone to recur despite GTR and eventually progress: they represent a challenge and are difficult to recognize at first diagnosis. SOX2 (Sex-determining region Y-box2) is a transcription regulator whose role is crucial for cell’s fate and maintenance of progenitor’s identity during embryogenesis, and homeostasis and regeneration in adult tissue through stem cell activity preservation. We reviewed meningioma cases surgically treated at Gemelli Hospital, Rome between 2014 and 2019. We included all patients with diagnosis of grade 3 meningiomas, both progressive and de novo, grade 2 with at least one surgical recurrence after GTR and benign grade 1 and grade 2 without recurrence at 10 and 5 years long follow-up respectively. SOX2 expression was evaluated through IHC and RT-PCR. Its role in predicting progression, recurrence, OS and PFS was investigated. 87 patients were included: 16 de novo grade 3 meningioma, 7 progressive grade 1, 13 progressive grade 2, 12 recurrent grade 2, 20 benign grade 1, 19 benign grade 2. The IHC method for SOX2 was validated by correlation between IHC score and mRNA levels (Spearman R=0.0398, p=0.001, AUC 0.87). Although SOX2 expression is related to WHO grade in the series, its status doesn’t change with progression. SOX2 expression at first surgery is related to risk of progression (p< 0,0001) and represents a grade independent prognostic factor for PFS and OS (PFS 38,41 months in positive cases vs not reached in negative cases; p< 0,0001; OS 173,9 months in positive cases vs not reached in negative cases; p=0,0001) and both in grade 1 and grade 2. Histomorphological criteria, cornerstone of the current WHO classification, are inadequate to predict aggressiveness. SOX2 expression since first diagnosis is able to point out meningiomas prone to recur and progress. SOX2 status could integrate current classification as molecular biomarker of stemness and aggressiveness.
BIOM-62. INTEGRATED GENOMIC PROﬁLING OF LONG-TERM GLIOBLASTOMA SURVIVORS
Authors: Xu PengFei , Chen ZhongPing
Published: November 2022

Glioblastoma (GBM) is a fatal brain tumor, and few patients survive beyond 5 years. Therefore, a study of genomic alterations in GBM long-term survivors is essential for insights into tumor biology and biomarker identiﬁcation. In our study, 13 GBM long-term survivors (overall survival >60 months) and 19 short-term survivors (overall survival < 24 months) were retrospectively collected, and surgically resected tumor tissues and normal blood controls were extracted and were performed whole exome sequencing and transcriptome sequencing. Our results revealed that although no significant differences were found in the composition of driver genes between the two groups, mutation signature analysis of two GBM groups revealed that the proportion of mutation signature 19 was higher in the longer survivors than in the shorter survivors (P=0.059). Analysis of copy number variants showed that the longer survivors group had higher copy number variants at the chromosomal level (P=0.049). At the chromosome Arm level, the proportion of 19p amplification and 19q amplification in the longer survivors group was significantly higher than in the short survival group (P=0.001/0.002). And in the TCGA GBM dataset, GBM patients with 19p amplification also had a better prognosis (log-rank P=0.04). In conclusion, the proportion of mutation signature 19 and amplification of 19p was potential prognostic molecular features for GBM.
BIOS-01. MANAGEMENT OF OPTIC PATHWAY GLIOMA: A SYSTEMATIC REVIEW AND META-ANALYSIS
Authors: Yousefi Omid , Azami Pouria , Sabahi Mohammadmahdi , Adada Badih , Borghei-Razavi Hamid
Published: November 2022

In the current study, we systematically review the literature regarding the management of optic pathway glioma (OPG). This review will analyze demographics, information regarding the type of treatment, radiological and clinical (visual) outcomes, and also complications. Article selection was performed by searching PubMed, Web of Science, and Cochrane databases. Of the 105 eligible studies, a total of 4177 patients underwent different therapeutic modalities including surgery, radiotherapy, and chemotherapy. The mean age was 8.17 years and the gender ratio was 97 males per 100 females. Based on the available data, the mean follow-up was 98.6 months and 48.7% of the patients were known cases of the neurofibromatosis type1. According to the Dodge classification 1104, 941, and 1353 tumors were D1, D2, and D3, respectively. The toxicity induced by either chemo- or radiotherapy was the most common complication, followed by the ophthalmologic complications rather than visual acuity exacerbation. The pooled mortality rate was 0.12 (95%CI 0.09–0.14). Due to the unrepresentative data, improved and not changed outcomes were classified as the favorable outcome and worsened as an unfavorable. Meta-analyses were performed to determine the rate of clinical and radiological favorable outcomes. In terms of visual assessment, the pooled rate of a favorable outcome in chemotherapy, radiotherapy, and surgery was 0.74, 0.81, and 0.65, respectively and the overall pooled rate of the favorable outcome is 0.75 (95%CI 0.70–0.80). In terms of radiological assessment, the rate of a favorable outcome following chemotherapy, radiotherapy, and surgery was 0.71, 0.74, and 0.67, respectively and the overall pooled rate of the favorable outcome is 0.71 (95%CI 0.65–0.76). The subgroup analysis revealed no significant difference in the rate of clinical and radiological favorable outcomes between the different treatment modalities (P > 0.05). Our analyses showed that each therapeutic modality represents viable treatment options to achieve remission for these patients.
CNSC-05. ELECTROPHYSIOLOGICAL PATTERNS OF GLIOMA-INDUCED NEURONAL NETWORK REMODELING ARE CONSERVED ACROSS TUMOR SUBTYPE
Authors: Aabedi Alexander , Lipkin Benjamin , Young Jacob S , Hinkley Leighton , Findlay Anne , Daniel Andy , Krishna Saritha , Umbach Gray , Kaur Jasleen , Berger Mitchel S , Molinaro Annette , Brang David , Nagarajan Srikantan , Hervey-Jumper Shawn L
Published: November 2022

Recent evidence indicates that diffuse gliomas engage with neurons at the single-unit and circuit level through differing mechanisms. Certain malignant gliomas form glioma-neuron excitatory glutamatergic synapses and modulate neuron-neuron synapses through activity-dependent paracrine signaling, while others establish glioma-glioma connections via tumor microtubes. It is therefore possible that diffuse gliomas remodel neuronal circuits in a defined and predictable manner and demonstrate distinct electrophysiological profiles with prognostic and therapeutic significance. Here we apply machine learning principles in 140 patients across glioma subtypes to uncover unique electrophysiological features non-invasively via magnetoencephalography (discovery dataset) followed by feature validation using subdural electrocorticography (validation dataset). Following spatial-temporal registration, we fit an elastic net logistic regression classifier to distinguish between power spectra arising from glioma-remodeled cortex and within-subject control conditions. Model significance was determined non-parametrically by re-training each model 1,000 times with randomly permuted class labels and testing the true phi coefficient against the null distribution. In the discovery dataset, we were able to classify glioma infiltration based on tumor intrinsic neuronal activity (p < 0.05) in 127 patients (90.7%). We identified 30 electrophysiological features which revealed increased power in the delta range (1-4 Hz) and decreased power in the beta range (12-20 Hz) as a unique signature of glioma remodeling (p < 0.05) which was preserved in the validation dataset as well as across WHO 2021 diffuse glioma subtypes. In order to identify gene expression programs and signaling mechanisms that may contribute to glioma-induced remodeling but are potentially not identified in the current clinical classification scheme, we assessed targeted, next generation sequencing and DNA mutations as covariates, which again demonstrated the significance of the delta-beta spectral features. These data support converging mechanisms of glioma-induced neuronal network remodeling across tumor subtypes, setting the stage for novel therapies such as neuromodulation.
CNSC-07. MECHANISMS OF GLIOBLASTOMA-INDUCED CORTICAL REMODELING IDENTIFY THERAPEUTIC VULNERABILITIES
Authors: Krishna Saritha , Choudhury Abrar , Keough Michael , Ni Lijun , Seo Kyounghee , Aabedi Alexander , Popova Galina , Kakaizada Sofia , Findlay Anne , Lee Anthony , Gonzales Cesar , Sudharshan Rasika , Cao Caroline , Venkatesh Humsa , Almeida Nyle , Nagarajan Srikantan , Berger Mitchel S , Raleigh David , Brang David , Monje Michelle , Hervey-Jumper Shawn L
Published: November 2022

Prior work demonstrated synaptic integration of malignant gliomas into neural circuits induces local hyperexcitability and tumor proliferation. However, prognostication and therapeutic vulnerabilities are lacking from preclinical models. Here, we integrate in vivo and in vitro neurophysiology spatially matched with gene expression programs and protein signaling mechanisms across 66 IDH WT glioblastoma patients to identify thrombospondin-1 (TSP-1) as a molecular driver of glioma-induced network remodeling. Bulk and single cell RNA-sequencing of 11 intratumoral regions maintaining functional connectivity (13,730 cells analyzed) revealed a distinct neurogenic signature enriched for the synaptogenic factor TSP-1. Mechanistic and functional studies validating therapeutic vulnerabilities to TSP-1 silencing by shRNA knockdown and FDA-approved inhibitors (Gabapentin and LSKL) of excitatory synapse formation through the gabapentin a2d-1 receptor was performed in vitro and in vivo. Glioma-neuron co-culture of TSP-1 overexpressing cells demonstrated increased Ki67 proliferation and tumor microtube (TMT) formation when cultured in the presence of neurons. Pharmacological inhibition of TSP-1 using gabapentin or TSP-1 shRNA inhibited the proliferation and TMT-mediated expansion. Hippocampal xenografted mice with TSP-1 over expressing primary patient cultures demonstrated shorter survival and gabapentin treatment of xenografted mice significantly reduced the proliferation of TSP-1 overexpressing cells in vivo. Electrophysiological properties of glioma-neuron co-cultures analyzed using multi-electrode array (MEA) demonstrated increased neuronal spiking activity and network burst synchrony in the presence of TSP-1 over expressing cells. Strikingly, these increases were eliminated in the presence of gabapentin. We modeled survival risk in patients incorporating the effects of glioma intrinsic neuronal activity, molecular, therapeutic, and clinical factors on overall survival by recursive partitioning. Three risk groups were identified based on tumor intrinsic neuronal activity, pre- and post-operative tumor volume with shortest overall survival in patients with glioma intrinsic neuronal activity. These data identify glioma-induced secretion of TSP-1 as a key contributor of tumor proliferation shedding light on new therapies.
TMET-05. MAGMAS FACILITATES METABOLIC CHANGES INDUCED BY STRESSORS IN GLIOBLASTOMA
Authors: Lepe Javier , Lomeli Naomi , Douglas Chris , Di Kaijun , Bota Daniela
Published: November 2022

The dynamic nature of tumor microenvironments contributes to tumor heterogeneity generating subpopulations of cells that are resistant to treatment in glioblastoma (GBM). The high recurrent rate of GBM tumors in patients can partially be explained by the presence of glioma stem cells (GSCs), which are thought to give rise to resistant clones against chemotherapy. As solid tumors expand, cancer cells can disrupt the tumor microenviroment by disrupting the blood brain barrier. Pericytes and astrocytes detach from the vascular endothelial cells, forming leaky vessels, which leads to thrombosis and eventually necrosis. Necrosis is a hallmark signature of GBM, as oxygen and nutrient supply runs low which can be observed through contrast imaging. Cancer cells go through a phenotypic change by upregulating stemness genes and glycolytic metabolism. Cells migrate away from hypoxic and nutrient deprived regions forming pseudopalisading cells which are an indication of cells becoming more invasive and malignant. Mitochondrial protein trafficking is a tightly regulated mechanism which selectively allows specific peptides carrying a mitochondrial targeting sequence (MTS) to be transported through the TOM40 and TIM23 complexes. Magmas, a TIM23 subunit, negatively regulates DNAJC19 by inhibiting its stimulatory activity on Hsp70 in the mitochondrial matrix. The regulation of the ATPase activity on Hsp70 is critical for processing pre-cursor proteins through the TIM23 complex into the mitochondrial matrix. Our laboratory has uncovered a novel role of Magmas activity in GBM cells under serum starved conditions in vitro. Magmas is downregulated in serum starved cells which allows for an increase of mitochondrial matrix proteins, which include key subunits important for forming electron transport chain complexes. This influx of ETC proteins can explain how cells are able to reduce aerobic glycolysis and increase oxidative phosphorylation (OXPHOS), a mechanism that can be exploited for potential therapeutic treatment in patients with GBM.
TMET-07. MOLECULAR MECHANISM OF EXQUISITE SENSITIVITY OF DIFFUSE MIDLINE GLIOMA TO DE NOVO PYRIMIDINE BIOSYNTHESIS
Authors: Pal Sharmistha , Savani Milan , Kaplan Jakub , Stopka Sylwia Sylwia A , Nguyen Huy , Regan Michael , Agar Nathalie , McBrayer Samuel , Haas-Kogan Daphne
Published: November 2022

Diffuse midline glioma (DMG) is a lethal pediatric brain cancer in dire need for therapeutic breakthroughs. To identify intrinsic addictions and therapeutic targets for DMG, we conducted a genome-wide k¬¬¬¬nockout CRISPR screen that identified de novo pyrimidine biosynthesis pathway as a targetable dependency. Since pyrimidine nucleotides can be synthesized by salvage and de novo pathways, identification of the latter as a dependency indicated a prominent role of de novo pathway in establishing the pyrimidine nucleotide pool in DMG. We investigated the molecular mechanism underlying this dependency using metabolic tracing of 15N-glutamine and genetic approaches. We report that DMG cells derive the majority of UMP (70%) through de novo synthesis, along with significantly elevated flux through the pyrimidine degradation pathway. High flux of 15N- labeled UMP through pyrimidine degradation in DMGs suggests that substrates (uridine and uracil) required for pyrimidine nucleotide salvage are limited, thus enhancing the dependency on de novo biosynthesis. To further confirm the causal role of pyrimidine degradation in driving de novo pathway dependency in DMG, we knocked down DPYD, the enzyme catalyzing the first committed step in pyrimidine degradation, using inducible shRNAs. Knockdown of DPYD diminished sensitivity of DMGs to de novo pathway inhibition as it rescued UMP pools and resultant DNA damage. Conversely, overexpression of DPYD in adult glioblastomas enhanced their sensitivity to de novo pyrimidine synthesis inhibition which was accompanied by greater depletion of UMP and induction of DNA damage. Consistent with this mechanism, we observed downregulation of DPYD in DMGs that acquired resistance to antagonists of de novo pyrimidine synthesis. Taken together, we have uncovered DPYD as a predictive biomarker of sensitivity to de novo pyrimidine synthesis inhibitors.
TMET-14. TUMOR-ASSOCIATED MYELOID CELL-DERIVED CREATINE PROMOTES GLIOBLASTOMA GROWTH IN HYPOXIC NICHES AND PSEUDOPALISADING TUMOR REGIONS
Authors: Zolp Andrew , Rashidi Aida , Chia Tzu-Yi , Dmello Crismita , Arrieta Victor , Zhao Junfei , Castro Brandyn , Markwell Steven , Heiland Deiter Henrik , Brat Daniel , Chandel Navdeep , Lesniak Maciej , Lee-Chang Catalina , Miska Jason
Published: November 2022

Glioblastoma (GBM) consists of a unique tumor microenvironment (TME) dominated by infiltrating tumor-associated myeloid cells (TAMCs). TAMCs are central to tumor growth and understanding how they support tumor progression is critical to identifying new therapeutic modalities. Examination of the metabolic and genetic phenotypes of TAMCs revealed that the de-novo creatine phenotype is central to their identity. Immunohistochemistry and multiplex fluorescence in GBM patient-derived tissue showed TAMC infiltration localizing to hypoxic pseudopalisading regions. Furthermore, single-cell RNAseq analysis of human and mouse models of GBM identified that the transporter of creatine, Slc6a8, is located on tumor cells within these regions. Spatial transcriptomics confirmed this transporter-synthesis gene compartmentalization is specific to hypoxic pseudopalisading regions, and further elucidated a radial glial cell gene signature for tumor cells expressing Slc6a8. Murine models recapitulated the TAMC de-novo creatine metabolic phenotype both ex-vivo and in-vitro. Metabolomics showed that TAMC-derived creatine can transfer to tumor cells in-vitro and is enhanced under hypoxic conditions. β-guanidinopropionic acid (β-GPA) is a creatine analog proposed to block Slc6a8 function and effectively blocked TAMC-derived creatine transfer to tumor cells in-vitro. Furthermore, β-GPA inhibited both the viability and size of spheres for tumor cells grown in stem-cell conditions. Lastly, inhibition of creatine transport using clinically relevant inhibitors enhanced survival following tumor implantation in murine models. This work highlights the key role of creatine in the pseudopalisading and hypoxic niche in GBM, offering evidence for a potential benefit in targeting this axis for GBM therapy regimens.
CNSC-21. CHARACTERIZATION OF NEURON-TUMOR INTERACTIONS USING HUMAN CO-CULTURES
Authors: Tetzlaff Svenja , Campos Joaquín , Nguyen Linh , Strahle Christopher , Wick Wolfgang , Kuner Thomas , Winkler Frank , Acuna Claudio , Venkataramani Varun
Published: November 2022

Glioblastoma are incurable brain tumors characterized by their colonization of the entire brain and their notorious therapeutic resistance. Recently, we discovered long membrane tubes called tumor microtubes contributing to invasion, network formation of tumor-tumor networks and therapeutic resistance. Subsequently, heterogeneous networks of neurons and glioblastoma cells were characterized, which can communicate by synaptic and perisynaptic contacts as well as by paracrine mechanisms. Currently used models of studying neuron-glioblastoma interactions are limited by the possibility to study glioblastoma in a defined human neuronal microenvironment. Here, we set out to derive excitatory and inhibitory neurons from embryonic stem cells via lentiviral reprogramming and co-cultured them with patient-derived glioblastoma cells. We could show that structural and functional neuron-glioblastoma synaptic contacts are formed. Functional communication between neurons and glioblastoma cells were characterized with calcium imaging, showing similar complex calcium dynamics previously characterized with in vivo imaging of patient-derived xenograft models. The single-cell glioblastoma morphology was morphometrically similar to that of human glioblastoma tissue. Tumor microtubes and the formation of tumor-tumor networks could be demonstrated. Additionally, glioblastoma invasion patterns in our human neuronal co-culture model resemble invasion patterns recently characterized with patient-derived xenograft models. Lastly, we investigated reciprocal neuron-glioblastoma interactions and longitudinally characterized neuronal activity with patch-clamp electrophysiology. In conclusion, we provide a novel human neuron-glioblastoma co-culture system allowing in-depth molecular and functional characterization for future Cancer Neuroscience studies.
TMET-18. TARGETING AMINO ACID METABOLIC VULNERABILITIES IN GLIOBLASTOMA
Authors: Ohba Shigeo , Teranishi Takao , Hirose Yuichi
Published: November 2022

Tumor cells have different metabolism from normal cell, which is called as cancer metabolism. In normal cells, asparagine is provided by asparagine synthetase (ASNS) from aspartate. On the other hand, in tumor cells, asparagine is needed to be taken in from outside the cells in addition to synthesized by ASNS within the cells, because of rapid growth of the tumor cells. Glioblastoma is one of the aggressive brain tumors, and temozolomide is frequently used. After glioblastoma cells acquire the resistance to temozolomide, no effective chemotherapy remained. The object of this study is to evaluate whether cancer metabolism, especially asparagine, could be a new target of treatment in primary and recurrent glioblastoma. Temozolomide-sensitive glioblastoma cell lines (U251, and U87), and U251- or U87 derived temozolomide-resistant cells, which were obtained after long treatment of temozolomide to parental cells, were used for the experiments. Genetical inhibition of ASNS using siRNA suppressed the proliferation of temozolomide-sensitive glioblastoma cells, inducing apoptosis. Adding of asparagine in the medium reversed the effect of siRNA targeting ASNS. L-asparaginase, which converts asparagine into aspartate, reduced the colonogenicity of glioblastoma cells. L-asparaginase increased the expression of mRNA of ASNS, and inhibition of ASNS potentiated L-asparaginase-induced anti-tumor effect. For temozolomide-resistant U251- or U87-derived cells, inhibition of ASNS also suppressed the colonogenicity of the cells, and inhibition of ASNS enhanced anti-tumor effect by L-asparaginase. In conclusion, targeting asparagine metabolism will be a therapeutic option for temozolomide-sensitive and temozolomide-resistant glioblastoma.
TMET-24. MITOCHONDRIAL AND GENE EXPRESSION CHANGES IN BRAIN TUMOR CELLS GROWN IN Β-HYDROXYBUTYRATE
Authors: Almekkawi Ahmad Kareem , Sheets Rachelle , Werner Brianna , Perryman Richard , Singh Indrapal , Karim Mohammad , Frye Richard , Syed Nelofer , Scheck Adrienne
Published: November 2022

Malignant brain tumors are devastating diseases with poor outcomes. The search for more effective therapeutic combinations has led to investigation of the use of a therapeutic ketogenic diet (KD) as an adjuvant therapy based on the metabolic dysregulation that is a hallmark of cancer. KD sometimes results in extended survival, but like all cancer therapies the tumor eventually becomes resistant. Resistance can arise due to the “metabolic remodeling” of resistant cells due to limitations in nutrient availability and other signals from the tumor microenvironment. We are investigating the molecular and mitochondrial changes of tumor cells grown in β-hydroxybutyrate (BHB), the main ketone produced when following a therapeutic KD, to partially recapitulate the long-term effects of the KD on patients. Murine malignant glioma cells (GL261-luc2) were cultured long term in 2, 5 or 10mM BHB. The Agilent XFe96 Seahorse Analyzer was used to measure changes in cell metabolism. Epigenetic changes that occur in the mitochondria were interrogated using DNA methylation assays. Finally, we implanted BHB resistant glioma cells intracranially in mice and carried out RNAseq to determine the mechanisms by which these cells adapt. Seahorse analyses of GL261-luc2 cells grown in BHB demonstrated changes in several respiratory parameters including maximal respiration and reserve capacity. In addition, there is a statistically significant decrease in mitochondrial DNA methylation with increasing concentrations of BHB. RNAseq analysis of BHB resistant GL261 tumors showed changes in pathways related to mitochondrial translation and the electron transport chain. Our preliminary results show that the heterogeneity seen in these tumors is recapitulated in the various mitochondrial respiration parameters. Further, these may be altered as a consequence of BHB therapy. An understanding of the genetic and mitochondrial changes that occur when cells become resistant will lead to a more effective use of the KD as an adjuvant therapy.