bluuebunny/crossref_metadata_2025_split huggingface dataset:
BIMG-09. GLUTAMINE AND GLYCINE BY MR SPECTROSCOPY IDENTIFY AGGRESSIVE GLIOMAS
Authors: Choi Changho , Askari Pegah , Daoud Elena , Hatanpaa Kimmo , Raisanen Jack , Levy Michael , Pan Edward , Patel Toral , Mickey Bruce , Maher Elizabeth 
Published: March 2021

Abstract
Cancers reprogram their metabolism and the resulting alterations in metabolite abundance can be monitored in patients noninvasively using proton magnetic resonance spectroscopy (MRS). We evaluated glutamine, glycine and 2-hydroxyglutarate (2HG) in 27 adult subjects with gliomas (17 male and 10 female; age 22 - 69, median 39 years) using optimized MRS at 3T (PRESS TE 97ms) and examined their association with post-gadolinium enhancement, cell proliferation rate (MIB-1 labeling index), and overall survival of patients. The tumors included 9 glioblastomas (3 IDH mutated and 6 IDH wildtype), 10 astrocytomas (7 IDH mutated and 3 IDH wildtype), and 8 oligodendrogliomas (IDH mutated). The concentrations of glutamine and glycine were both significantly higher in enhancing tumors than in non-enhancing tumors (p=0.001 and 0.0001, respectively). The concentrations of glutamine and glycine were both positively correlated with MIB-1 (p=4E-5 and 1E-7, respectively). The sum of glutamine and glycine levels showed stronger association with MIB-1 (p=5E-10, r=0.89). In the Kaplan-Meier overall survival analysis, the survival was significantly shorter in patients with glutamine levels higher than 4.1 mM than those with concentrations less than 4.1 mM (p=0.02). For glycine, the patients with higher than 2.4 mM showed association with poor survival (p=0.03). The sum of glutamine and glycine levels showed stronger association with overall survival (p=0.008, cutoff 8.5mM). 2HG level greater than 0.5 mM was associated with long survival (p=0.01). We tested metabolic ratios to 2HG, in which 2HG estimates less than 1 mM were put as 1 mM (avoiding infinite ratios arising from null 2HG cases). The glutamine/2HG, glycine/2HG, and (glutamine+glycine)/2HG showed strong association with overall survival (p=2E-4, 2E-5 and 4.5E-7, respectively). Our data suggest that increased metabolism of glutamine and glycine is closely associated with rapid cell proliferation and poor survival, suggesting the metabolites are imaging biomarkers of glioma aggressiveness.
BIMG-10. IDH1 MUTATIONS INDUCE ORGANELLE DEFECTS VIA DYSREGULATED PHOSPHOLIPIDS
Authors: Yamasaki Tomohiro , Lita Adrian , Zhang Lumin , Rodado Victor Ruiz , Dowdy Tyrone , Gilbert Mark , Larion Mioara 
Published: March 2021

Abstract

BACKGROUND
Metabolic alterations of lipids have been identified as a hallmark of neoplasms, with the most prevalent being the balance between saturated fatty acid (SFA) and monosaturated fatty acid (MUFA). Stearoyl-CoA desaturase1 (SCD1), converting SFA to MUFA, is increased in many cancers, leading to worse prognosis. In glioma, the role of SCD1 remains unknown. Isocitrate dehydrogenase (IDH) mutations have been most commonly observed in glioma, but the involvement of mutant IDH in SCD1 expression also remains unknown.

METHODS
We conducted metabolic analysis to examine the alteration of SCD1 expression in genetically engineered glioma cell lines and normal human astrocyte (NHA). Lipid metabolic analysis was conducted by using LC-MS, Raman Imaging Microscopy and SCD1 expression was examined by Western-blotting and RT-PCR method. Electron microscopy was employed for organelle structure and genetic knock-down of SCD1 gene was performed.

RESULT
Herein, we uncovered increased MUFA and their phospholipids in Endoplasmic Reticulum (ER), generated by IDH1 mutation, that were responsible for Golgi and ER dilation. RNA seq data from The Cancer Genome Atlas, showed that SCD1 expression was significantly higher in IDH mutant gliomas compared with wild-type, and high SCD1 expression was associated with longer survival. Inhibition of IDH1 mutation or SCD1 silencing restored ER and Golgi morphology, while D-2HG and oleic acid induced morphological defects in these organelles. Moreover, addition of oleic acid, which tilts the balance towards elevated levels of MUFA, produced IDH1 mutant-specific cellular apoptosis.

CONCLUSION
Collectively, our results suggest that IDH1 mutant-induced SCD overexpression can rearrange the distribution of lipids in the organelles of glioma cells, providing a new insight on the link between lipids metabolism and organelle morphology in these cells, with potential and unique therapeutic implications. The results of the present study may also provide novel insights into the discovery of metabolic biomarkers for IDH mutant gliomas.
BIMG-12. [18F]FLUCICLOVINE PET TO DISTINGUISH PSEUDOPROGRESSION FROM TUMOR PROGRESSION IN POST-TREATMENT GLIOBLASTOMA
Authors: Nabavizadeh Ali , Doot Robert , Young Anthony , Nasrallah MacLean , Ware Jeffrey , Schubert Erin , Henderson Fraser , Pantel Austin , Desai Arati , Bagley Stephen , O’Rourke Donald , Brem Steven 
Published: March 2021

Abstract

PURPOSE
Differentiation of true tumor progression from pseudoprogression (PsP) is a major unmet need in patients with glioblastoma (GBM). [18F]Fluciclovine is a synthetic amino acid PET radiotracer that is FDA approved in the setting of biochemical recurrence in prostate cancer. The aim of this study was to assess the value of [18F]Fluciclovine PET in differentiation of true tumor progression and PsP in post-treatment of glioblastoma.

METHODS
15 patients with GBM with new contrast-enhancing lesions or lesions showing increased enhancement (&gt;25% increase) on standard MRI after completion of radiation underwent 60-minutes dynamic [18F]Fluciclovine PET imaging. Patients subsequently (within 1 week) underwent resection of the enhancing lesion and the tumor percentage vs treatment-related changes were quantified on histopathology. Patients were considered true tumor progression if tumor represented ≥ 50% of the resected specimen and considered PsP if treatment-related changes represented ≥70% of the resected specimen. Summed 30- to 40-minute post-injection PET images were used to measure SUVpeak, SUVmax, and 50% threshold SUVmean.

RESULTS
10 patients with true tumor progression and 5 patients with PsP were included. Patients who demonstrated true tumor progression had significantly higher SUVpeak compared to patients with PsP (5.3±1.4 vs 3.1± 0.9, p=0.002, AUC=0.92, p&lt;0.0001). SUVpeak cut-off of 3.5 provided 100% sensitivity, 80% specificity and 93% accuracy for differentiation of true tumor progression from PsP. There was a moderate to strong correlation between SUVpeak and tumor percentage on histopathology (Rho= 0.68, p=0.004). Alternative SUV measures had similar performance.

DISCUSSION
Our preliminary results indicated that [18F]Fluciclovine PET imaging can accurately differentiate true tumor progression from PsP. Further studies are required to confirm these promising early results and determine the optimal criteria for interpreting [18F]Fluciclovine PET to distinguish PsP from true tumor progression.
BIMG-14. IDENTIFICATION OF IDH MUTATION STATUS USING PROTON MR SPECTROSCOPY AND MASS SPECTROMETRY: A STUDY OF 178 GLIOMAS
Authors: Sacli-Bilmez Banu , Akin-Levi Cansu , Danyeli Ayça Ersen , Yakicier Cengiz , Pamir M Necmettin , Özduman Koray , Dincer Alp , Can Ozge , Ozturk-Isik Esin 
Published: March 2021

Abstract
IDH mutation, a key factor in predicting glioma prognosis, alters the levels of some metabolites in brain, including 2-hydroxyglutarate (2HG), glutamine (Gln), and glutathione (GSH). While proton MR spectroscopy (1H-MRS) enables in-vivo detection of these metabolites, liquid chromatography-mass spectrometry (LC-MS/MS) is a sensitive in-vitro method to measure absolute metabolite concentrations. This study aims to examine the correlation of metabolic concentrations measured using 1H-MRS and LC-MS/MS in gliomas, and to detect IDH mutation with machine learning based on 1H-MRS and LC-MS/MS metabolic intensities. The patient cohort included 178 glioma patients (111M/67F, mean age:44.09±13.95 years, 100 IDH-mut, 78 IDH-wt). The patients were scanned pre-surgery by a 3T MR scanner with a 32-channel head coil. 1H-MRS was obtained from a manually placed region of interest with no necrosis, edema, and hemorrhage, using a Point Resolved Spectroscopy (PRESS) sequence (TR/TE=2000/30ms). LCModel software was used for quantification of eighteen metabolites of 1H-MRS data. Metabolite concentrations including creatine (Cr), choline (Cho), Gln, glutamate (Glu), gamma-aminobutyric acid (GABA), N-acetyl aspartate (NAA), myo-inositol (mIns), 2HG, and lactate (Lac) were also determined with LC-MS/MS for surgical specimen of the same patients. Spearman correlation coefficients were calculated between the metabolite concentrations measured with 1H-MRS and LC-MS/MS. Additionally, machine-learning algorithms were used to detect IDH mutation in gliomas based on metabolite concentrations obtained with 1H-MRS and LC-MS/MS. Consequently, there were statistically significant correlations between 1H-MRS and LC-MS/MS results for 2HG (p=0.036), Cr (p=0.009), mIns (p&lt;0.001), Lac (p=0.007) and NAA (p=0.004). IDH mutation was detected with an accuracy of 92.42% (sensitivity=91.70%, specificity=93.46) and 82.94% (sensitivity=84.04, specificity=81.43) based on LC-MS/MS and 1H-MRS metabolic intensities, respectively. In conclusion, 1H-MRS and LC-MS/MS metabolic intensities were highly correlated and these techniques were successful in identifying IDH mutation in gliomas. This study has been supported by TUBITAK 1003 grant 216S432.
BIMG-17. EFFECTS OF THE TUMOUR MICROENVIRONMENT ON PROTOPORPHYRIN IX ACCUMULATION IN GLIOBLASTOMA
Authors: Walker Paul , Finch Alina , Wykes Victoria , Watts Colin , Tennant Dan 
Published: March 2021

Abstract
Glioblastoma is the most common primary brain tumour and has a poor prognosis. The median survival is less than two years despite clinical intervention that usually involves the resection of the tumour volume, chemotherapy and radiotherapy. Achieving gross-total resection is challenging due to poorly defined boundaries as a result of tumour infiltration. Fluorescence-guided surgery (FGS) utilises an apparently selective accumulation of protoporphyrin IX (PPIX) that occurs in areas of glioblastoma after administration of the metabolite, 5-aminolevulinic acid (5-ALA). 5-ALA and the fluorescent metabolite, PPIX, sit within the endogenous heme biosynthetic pathway, which suggests that FGS is not only an important clinical tool, but also highlights differing metabolic phenotypes naturally present throughout the tumour. Genetic and mechanistic studies into this phenomenon have shown that differential expression of metabolite transporters, altered activity of the heme pathway enzymes and variable nutrient availability are all factors in the accumulation of PPIX. However, little is known about the cellular driving force for the uptake of 5-ALA and subsequent conversion into PPIX. Our data suggest that different microenvironments within the tumour alter the activity of the heme biosynthetic pathway, resulting in differential fluorescence in glioblastoma. It paves the way for work to alter the glioblastoma microenvironment in order to further improve the use of FGS in guiding surgery across these devastating tumours.
DDRE-01. METABOLIC PLASTICITY AND HETEROGENEITY IN IDH1MUT CELL LINES PRODUCES RESISTANCE TO GLUTAMINASE INHIBITION BY CB839
Authors: Larion Mioara , Ruiz-Rodado Victor 
Published: March 2021

Abstract

BACKGROUND
Mutant IDH1 (IDH1mut) gliomas have characteristic genetic and metabolic profiles and exhibit phenotype that is distinct from their wild-type counterparts. The glutamine/glutamate pathway has been hypothesized as a selective therapeutic target in IDH1mut gliomas. However, little information exists on the contribution of this pathway to the formation of D-2-hydroxyglutarate (D-2HG), a hallmark of IDHmut cells, and the metabolic consequences of inhibiting this pathway.

METHODS
We employed an untargeted metabolic profiling approach in order to detect metabolic changes arising from glutaminase (GLS) inhibition treatment. Subsequently, 13C metabolic tracing analysis through a combined Nuclear Magnetic Resonance and Liquid Chromatography-Mass Spectrometry approach, we explored the fate of glutamine and glucose under treatment with CB839 a glutaminase-GLS-inhibitor and their respective contributions to D-2HG formation.

RESULTS AND CONCLUSIONS
The effects of CB839 on cellular proliferation differed among the cell lines tested, leading to designations of GLS-inhibition super-sensitive, -sensitive or -resistant. Our data indicates a decrease in the production of downstream metabolites of glutamate, including those involved in the TCA cycle, when treating the sensitive cells with CB839 (glutaminase -GLS- inhibitor). Notably, CB839-sensitive IDH1mutcells respond to GLS inhibition by upregulating glycolysis and lactate production. In contrast, CB839-resistantIDH1mut cell lines do not rely only on glutamine for the sustenance of TCA cycle. In these cells, glucose contribution to TCA is enough to compensate the downregulation of glutamine-derived TCA metabolites. This investigation reveals that the glutamine/glutamate pathway contributes differentially to D-2HG in a cell-line dependent fashion on a panel of IDHmut cell lines. Further, these results demonstrate that there is a heterogeneous landscape of IDH1mut metabolic phenotypes. This underscores the importance of detailed metabolic profiling of IDH1mut patients prior to the decision to target glutamine/glutamate pathway clinically.
DDRE-05. STEAROYL COA DESATURASE IS ESSENTIAL FOR REGULATION OF ENDOPLASMIC RETICULUM HOMEOSTASIS AND TUMOR GROWTH IN GLIOBLASTOMA CANCER STEM CELLS
Authors: Park David , Badr Christian 
Published: March 2021

Abstract

INTRODUCTION
Emerging evidence suggest that, in addition to glucose, fatty acids can also drive glioma growth. Increased lipid synthesis is one of the metabolic hallmarks of cancer, and indeed, unsaturated fatty acids (UFA) are particularly abundant in glioblastoma. However, the exact role of fatty acids in GBM tumors remains unclear. Blocking fatty acids synthesis can present a new therapy for GBM.

METHODS
Through targeted inhibitors screening on glioma stem cells (GSCs), we found that they are highly susceptible to Stearoyl CoA Desaturase 1 (SCD1) inhibitors. SCD1 is a key enzyme responsible for the conversion of saturated fatty acids (SFA) to UFA. 1) Through cell-based assays and immunoblot analyses, we tried to understand the role of UFA, SFA and SCD1 in GSCs differentiation and proliferation. We investigated the mechanism between fatty acids and tumor growth through ER stress modulation linked with SCD1 expression. 2) As we found that GSCs are highly susceptible to SCD1 inhibition, we tested CAY, SCD1 inhibitor, in GSCs orthotopic mouse models and assess its effect on tumor growth and overall survival.

RESULTS
We found that GSCs with extensive self-renewal capacity have an increased dependence on SCD1 activity. Through immunoblot analyses, we demonstrated that SCD1 inhibition exacerbates ER stress through accumulation of SFA and SCD1-mediated UFA synthesis mitigates ER stress. Survival analyses between SCD1 inhibitor-treated group and control group showed significant survival benefit in SCD1-inhibitor-treated group, in both mesenchymal (p=0.008, 35 days vs 18) and proneural (p=0.0002) type glioma cells (n=8/groups).

CONCLUSIONS
We demonstrate that SCD1, the fatty acid desaturase, is essential for the maintenance of glioblastoma cancer stem cells. SCD1 is activated by ER stress and exerts a cytoprotective function by regulating ER homeostasis, thus favoring survival and tumor growth. Pharmacological targeting of SCD1 exhibits potent therapeutic efficacy in brain tumor mouse models.
DDRE-12. HETEROGENOUS RESPONSE OF IDH-MUTANT AND IDH-WT GLIOMA TO NAMPT INHIBITION
Authors: Rahman Masum , Hirte Renee , Olson Ian , Mansour Moustafa , Ikram Samar , MunozCasabella Amanda , Sutiwisesak Rujapope , Carlstrom Lucas , Warrington Arthur , Rajani Karishma , Sarkaria Jann , Burns Terry 
Published: March 2021

Abstract

BACKGROUND
NAD+ is required for cell metabolism and DNA repair. It is generated from nicotinic acid (NA) by NAPRT and from Nicotinamide (NAM) by NAMPT. D2HG in IDH-mutant tumors methylates and inactivates NAPRT, increasing dependence on NAMPT. Toxic side effects of NAMPT inhibition can be prevented by NA supplementation in healthy cells without NAPRT methylation. A1326133 is a recently described CNS-penetrant NAMPT inhibitor hypothesized to selectively eliminate IDH-mutant NAPRT-methylated gliomas, likely in combination with other therapies. Our group is looking for biomarkers of drug efficacy to augment individualized therapies. To that end, we sought to identify GBM cell lines with varying sensitivity to NAMPT inhibition.

METHODS
Human non-immortalized astrocytes and human GBM cell lines were utilized from the Mayo Clinic Glioma patient-derived xenograft resource, including IDH-R132Hmutant lines (GBM164, 196) and IDH-WT lines (GBM6, 12, 76). Cell viability was analyzed after 4days incubation with the NAMPT inhibitor, A1326133 +/- Temozolomide (TMZ) or NA. IC50 for A1326133 was estimated based on intracellular ATP using Cell-Titer-Glo.

RESULTS
Marked heterogeneity between lines was observed in response to A1326133 +/- NA or TMZ. Sensitive and resistant lines were identified among both IDH-mutant and IDH-WT cell lines. IC50s: GBM164, 12, 6, 196 and 76 were 5.6, 9.3, 39.2, 910, and 9455nM, respectively. NA partially rescued GBM164 by NA (IC50 increased to 20.8nM) but not GBM6 nor 12. IC50 for Human astrocytes was 221.7nM, but &gt;10,000nM with NA. Addition of TMZ did not improve A1326133 efficacy.

CONCLUSION
Our data illustrate the potential utility of NAMPT inhibition to kill a subset of IDH-WT and IDH mutant lines, but conflict with previously reported TMZ synergy and correlation with mutant IDH. NA may increase safety but could decrease efficacy in certain lines. Ongoing studies seek metabolic biomarkers of therapeutic efficacy to guide individualized therapy with NAMPT inhibitors.
DDRE-13. INHIBITION OF EXTRACELLULAR CARBONIC ANHYDRASES INHIBITS GLIOBLASTOMA CELL INVASION
Authors: Proescholdt Martin , Zhenwei Qiu , Annette Lohmeier , Nils-Ole Schmidt , Marsha Merrill 
Published: March 2021

Abstract

OBJECTIVE
Malignant gliomas metabolize glucose preferably by glycolysis which is in accordance with the Warburg effect. This induces a high demand of glucose combined with a significant lactic acid load. The hypoxia-inducible carbonic anhydrase (CA) IX has been shown to moderate the extrusion of hydrogen ions into the extracellular space. Since the acidification of the extracellular environment contributes to host tissue invasion due to activation of proteolytic enzymes, we hypothesized that CA IX plays an important role in malignant glioma Recently, specific small molecule inhibitors of this enzyme have been developed and may provide an innovative strategy for anti – invasive treatment.

METHODS
Two established and 4 primary GBM cell lines (2 with mesenchymal and 2 with proneural transcriptional profile) were exposed to the CAIX inhibitor U104 under normoxic and hypoxic conditions. Cell toxicity was measured by ATP and crystal violet assay. For invasion assessment, a matrigel invasion chamber system with 8 µm pore size polycarbonate filter was used. CAIX expression was analyzed by quantitative RTPCR and Western Blot.

RESULTS
Hypoxia significantly induced CAIX expression in all cell lines. Invasiveness increased significantly under hypoxic conditions in the mesenchymal cells (p &lt; 0.01). Regardless of oxygenation status, the mesenchymal group displayed significantly higher invasiveness compared to the proneural group (p = 0.006). Looking at all cell lines, invasion is significantly inhibited by U104, both under normoxic and hypoxic conditions (p &lt; 0.01). However, while the mesenchymal group showed the highest susceptibility to CAIX inhibition followed by the proneurally differentiated group, the established cell lines were entirely refractory to CAIX inhibition.

CONCLUSION
Our data demonstrate that CAIX inhibition can effectively inhibit invasion in malignant glioma cells independent from oxygenation status, however the effects are significantly influenced by cell type specific biological features.
DDRE-32. THERAPEUTIC TARGETING OF A NOVEL METABOLIC ADDICTION IN DIFFUSE MIDLINE GLIOMA
Authors: Pal Sharmistha , Kaplan Jakub P , Stopka Sylwia A , Regan Michael S , Hunsel Bradley R , Kann Benjamin H , Agar Nathalie Y R , Stiles Charles D , Cooney Tabitha M , Mueller Sabine , Chowdhury Dipanjan , Kaelin William G , McBrayer Samuel K , Haas-Kogan Daphne 
Published: March 2021

Abstract
Diffuse midline glioma (DMG) is a uniformly fatal pediatric cancer that is in need of urgent “outside the box” therapeutic approaches. Recent studies show that tumor cells adapt to stresses created by oncogenic mutations and these oncogene-induced adaptations create vulnerabilities that can be exploited to therapeutic ends. To uncover these oncogene-induced vulnerabilities in DMGs we conducted a genome-wide CRIPSR knockout screen in three DMG lines. The top common DMG dependency pathway that we discovered is de novo pyrimidine biosynthesis. Under normal conditions pyrimidine nucleotide needs are met through the salvage pathway. However, in DMG tumorigenesis, pyrimidine nucleotide synthesis is rewired such that the cells become dependent on the de novo biosynthesis pathway. De novo pyrimidine synthesis is catalyzed by CAD, DHODH and UMPS; all three genes are identified as dependencies in our screen and have been validated using shRNA mediated gene knockdown. Interestingly, DMG cells did not exhibit a dependency on the de novo purine biosynthesis pathway. Using a small molecule inhibitor of DHODH, BAY2402234 [currently studied in phase I trial for myeloid malignancies (NCT03404726)], we have demonstrated and validated, (i) efficacy and specificity of de novo pyrimidine synthesis inhibition in vitro in DMG cells; (ii) de novo pyrimidine addiction is not attributable to cell proliferation; (iii) DHODH inhibition induces apoptosis by hindering replication and inciting DNA damage; (iv) DHODH and ATR inhibition act synergistically to induce DMG cell death; and (v) critical in vivo efficacy. The in vivo experiment documents that BAY2402234 crosses the blood-brain barrier, is present in the brain at therapeutically relevant concentrations, suppresses de novo pyrimidine biosynthesis in intracranial DMG tumors in mice, and prolongs survival of orthotopic DMG tumor bearing mice. Taken together, our studies have identified a novel metabolic vulnerability that can be translated for the treatment of DMG patients.