bluuebunny/crossref_metadata_2025_split huggingface dataset:
P06.13.B GRAPHENE NANOSHEET ENABLED REPROGRAMMING OF GLIOBLASTOMA MYELOID CELLS TO UNLOCK THE EFFICACY OF IMMUNOTHERAPY
Authors: Kisby T , Stylianou M , Despotopoulou D , Parker H , Thawley A , Lozano N , MacDonald A , Kostarelos K 
Published: September 2023

Abstract

Immunotherapy has substantiated its promise and achieved striking clinical efficacy in at least a subset of patients in several cancer types. However, in patients with glioblastoma multiforme (GBM), immunotherapies have lacked efficacy as a consequence of the highly immunosuppressive “cold” tumour microenvironment. Small, thin graphene oxide (GO) nanosheets possess notable pharmacokinetic properties in GBM including deep translocation throughout the whole tumour volume and selective internalization by tumour associated macrophages and microglia (TAMMs) following local administration. The current study aimed to investigate whether this selective nanomaterial-TAMM interaction could be exploited to reprogram the immune-microenvironment of GBM. GO nanosheets were non-covalently complexed with a TLR7/8 agonist to form a stable immunomodulatory nanosystem (imodGO) which was tested in primary macrophages in vitro, and an orthotopic syngeneic GBM model in vivo. imodGO enhanced the polarization of macrophages toward a pro-inflammatory M1-like phenotype in vitro without disrupting their phagocytic or cytokine producing capacity. A single intratumoral administration of the same nanocomplex in an intracranial GL261 model was also effective in increasing M1-like TAMMs (CD86+, MHCII+, TNFα+) while decreasing immunosuppressive M2-like TAMMs (Ym1+, Arg1+) which resulted in a wider reprogramming of the brain tumour immune-microenvironment. Repeat imodGO administration was able to significantly inhibit tumour progression highlighting the therapeutic potential of this nanomaterial enabled immunomodulatory strategy. Based on these

RESULTS
, imodGO has emerged as a novel strategy to ameliorate the immunosuppressive character of GBM. Further work is warranted to assess whether imodGO could enhance the efficacy of systemic immunotherapies used in combination.
P07.05.B DNA-METHYLATION PROFILING IS AN EFFECTIVE ASSET FOR IDENTIFICATION OF TUMORS IN SUSPECTED, YET IMMUNOHISTOCHEMICALLY UNSPECIFIABLE, NEURO-ONCOLOGICAL CASES
Authors: Onken J S 
Published: September 2023

Abstract

BACKGROUND
Patients with a suspected neurooncological disease on radiographic images and no histopathological evidence of a tumor on the surgically retrieved tissue, pose a great challenge for clinicians and neuropathologists. DNA methylation-based classifications and copy number variation (CNV) analysis allow robust brain tumor classification. Here, we aim to evaluate their diagnostic properties in histopathologically unspecifiable or negative cases.

MATERIAL AND METHODS
We screened all neurosurgical cases, which underwent surgery at our institution between 2009 and 2021, with suspected neurooncological, but negative or unspecific histopathological diagnosis. We differentiated two groups: cases with cell-enriched, reactive tissue (+/- single tumor cells), insufficient to fully classify the lesion according to criteria of WHO for CNS tumors (group 1) and cases without histological evidence of tumor cells (group 2). In both groups, DNA methylation profiling was applied. Endpoints were diagnostic results of DNA methylation profiling (classifier Score ≥0.9) and evidence/no evidence of tumorigenic CNV alterations and eventually feasibility to make a diagnosis according to WHO 2021 criteria for brain tumors.

RESULTS
23 cases with unspecifiable histopathological diagnosis were identified, out of whom 5 (21.7%) were confirmed as healthy brain tissue via DNA-methylation profiling, whereas the eventual diagnosis of tumorigenic tissue was provided in 18 (78.3%) cases. 14 of these were assigned to group 1, 4 cases to group 2. In 6 cases of group 1 (42.9%) DNA-methylation profiling resulted in a successful tumor classification (score ≥0.9) compared to 1 case (25%) in group 2. CNV indicated tumorigenic alterations in 9 (64.3%) patients in group 1 and 2 (50%) patients in group 2. Specific tumor alterations in the CNV were found in 8 (57.1%) patients in group 1 and in 1 (25%) patient in group 2. Combining CNV and DNA-methylation profiling, a final tumor diagnosis according to WHO 2021 criteria was feasible in 9 (64.3%) cases in group 1 and 3 (75%) cases in group 2. Median time from surgery to histopathological diagnosis was 6 and 7 days and 32.5 and 31 days for integrated diagnosis (group 1 vs. group 2).

CONCLUSION
Molecular diagnostics with DNA-methylation profiling and CNV analysis substantially increases the likelihood of a definitive diagnosis according to 2021 WHO criteria for these challenging cases.
P08.02.B NEEDS OF SUPPORT IN GLIOBLASTOMA - FROM THE PATIENTS’ PERSPECTIVE
Authors: Ståhl P , Henoch I , Smits A , Rydenhag B , Ozanne A 
Published: September 2023

Abstract

BACKGROUND
Patients with IDH-wt glioblastoma carry a poor prognosis with a rapidly progressive illness trajectory. It is clear that the disabling symptoms experienced throughout the course of the disease require different kind of support depending on the nature of the problems. Previous research has drawn attention to support needs for brain tumour in general, but there is a lack of data focusing on patients with glioblastoma. This study aimed to explore the need of support during the illness trajectory for patients with glioblastoma considered from their own perspective.

MATERIAL AND METHODS
Twelve individual interviews with patients with glioblastoma were conducted during 2022 in Sweden. The inclusion criteria were histologically confirmed diagnosis of IDH-wt glioblastoma since at least 2 months and age ≥ 18 years at the time of diagnosis. The focus of the interviews was on experiences and specific needs of support. The interviews took place on one occasion, at a location based on the participant's preferences. Three interviews were conducted face-to-face, eight via telephone and one was a video interview. Interviews were audio recorded and transcribed verbatim. The analysis process based on qualitative content analysis is still in progress, but preliminary data will be discussed.

RESULTS
The preliminary results indicate that persons with glioblastoma need support in how to handle troublesome symptoms as well as practical support with e.g., transport and work abilities. More specifically, they wanted help in finding coping strategies and how to overcome deteriorated executive abilities. They found it positive to have been attributed a specific contact to discuss such questions or problems. Knowing whom to turn to in troublesome situations contributed to a sense of security even if the contact was not used. Furthermore, they wanted healthcare to be easily accessible, and to use an empathetic approach for the individual.

CONCLUSION
The preliminary results indicate that patients with glioblastoma need person-centred support throughout the course of the disease. Support is needed at different organizational healthcare levels; partly on a more comprehensive level, where accessibility is emphasised as an important factor, but also on an individual level where the attitude by the health care staff is seen as an important part of the support from the healthcare system.
P09.01.A IMPACT OF TIMING OF ANTISEIZURE MEDICATION WITHDRAWAL ON SEIZURE RECURRENCE IN GLIOMA PATIENTS: A RETROSPECTIVE OBSERVATIONAL STUDY
Authors: van der Meer P B , Dirven L , Fiocco M , Vos M J , Kerkhof M , Kouwenhoven M C , van den Bent M J , Taphoorn M J B , Koekkoek J A F 
Published: September 2023

Abstract

BACKGROUND
Withdrawal of antiseizure medication treatment (ASM) can be considered after completion of antitumour treatment in glioma patients who no longer suffer from seizures. We compared the risk of recurrent seizures after ASM withdrawal between patients with short-term, medium-term versus long-term seizure freedom after antitumour treatment.

MATERIAL AND METHODS
In this retrospective observational study, the primary outcome was time to recurrent seizure, from the starting date of no ASM treatment up to 36 months follow-up. Cox proportional hazards models were used to study the effect of risk factors on time to recurrent seizure. Stratification was done with information known at baseline. Short-term seizure freedom was defined as ≥3 months, but &lt;12 months; medium-term as 12-24 months; and long-term as ≥24 months seizure freedom from the date of last antitumour treatment.

RESULTS
This study comprised of 109 patients; 31% (34/109) were in the short-term, 29% (32/109) in the medium-term, and 39% (43/109) in the long-term group. A recurrent seizure was experienced by 44% (15/34) of the patients in the short-term, 31% (10/32) in the medium-term, and 44% (19/43) in the long-term group. Seizure recurrence risk was similar between patients in the short-term group as compared to the medium-term (cause-specific adjusted hazard ratio [aHR]=0.65 [95%CI=0.29-1.46]) and long-term group (cause-specific aHR=1.04 [95%CI=0.52-2.09]).

CONCLUSION
Seizure recurrence risk is relatively similar between patients with short-term, medium-term, and long-term seizure freedom after completion of antitumour treatment.
P10.05.A INDUCED SENESCENCE AND CALCIFICATION TO ANAPLASTIC MENINGIOMA
Authors: YOKOGAMI K , Watanabe T , Mizuguchi A , Yamashita S , Matsumoto F , Takeshima H 
Published: September 2023

Abstract

BACKGROUND
Although the majority of meningiomas are slow-growing and benign, atypical and anaplastic meningiomas behave aggressively with a penchant for recurrence. The 5-year risk of progression for incompletely resected meningiomas is over 80 percents. Specifically, the 5-year survival rates are 78-91% and 41-65% for atypical and anaplastic meningiomas, respectively. On the other hand, it has been reported that benign meningiomas with psammoma bodies or those with bone hyperplasia at the attachment site and subtype of high calcification have a low growth rate. Here we show that BMP signals essential for bone formation, especially GREM2 upstream inhibitor of BMP signals, are involved in meningioma growth, senescence and calcification.

MATERIAL AND METHODS
1) A long-term primary cultured meningioma and commercially available anaplastic meningioma (IOMM-lee and HKB-MM) are used. For immunohistochemistry and expression analysis, 87 surgical samples operated in our hospital were used.2) We observed changes in phenotype, proliferation rate and cell cycle by inhibiting BMP signal. Overexpression of GREM2, an upstream inhibitor of BMP signals, was performed in anaplastic meningiomas and analyzed comprehensively. Downloaded RNA-seq data from GREIN, a public database, and performed a comprehensive analysis of the extent of GREM2 expression and gene expression related to cellular senescence.

RESULTS
1) Inhibition of BMP signaling reduced proliferation. Moreover, long term inhibition of BMP signals induced calcification. 2) Expression of GREM2 related to proliferation in surgical samples. GREM2 mainly localized surrounding of psammoma bodies. 3)Overexpression of GREM2 increased sub-G1 population and inhibits cell proliferation. 4)Expression of GREM2 shifts tryptophan catabolism from Kynurenine/NAD/NADH to serotonin production. 5) Comprehensive analysis using RNA-seq data from GREIN showed that high expression of GREM2 decreases oxidative phosphorylation. 6)Senescence assay showed that inhibition of BMP signaling induced senescence.

CONCLUSION
Inhibition of BMP signaling reduced proliferation and induced calcification. The underlying mechanism is shifting tryptophan catabolism from Kynurenine/NADH/NAD to serotonin production.
P10.17.A GLUTAMINE METABOLISM AS A PROGNOSTIC FACTOR IN GBM AND OLIGODENDROGLIOMA
Authors: Trybula M , Lysiak M , Malmstrom A , Soderkvist P 
Published: September 2023

Abstract

BACKGROUND
Increased uptake of principal nutrients is one of the attributes of cancer cells. A recent study has shown that glutamine, but not glucose, consumption differed markedly between gliomas and adjacent healthy tissue. However, the prognostic role of glutaminolysis or glutaminolysis-related genes (GRGs) in gliomas remains unclear. Here we sought to determine if the GRG signature correlates with glioma patient survival and if it could identify patients with different outcomes.

MATERIAL AND METHODS
The RNA-seq and clinical data for The Cancer Genome Atlas (TCGA) was obtained from the GlioVis webpage. We compared the expression of the GRGs (GLUD1, GLUL, GLS1, GLS2, GOT1, GOT2, GPT, GPT2, SLC1A5, and SLC7A5) between 4 non-tumor, 220 IDH wild-type (IDHwt) and 389 IDH mutant (IDHmut) gliomas, of which 154 harbored 1p/19q codeletion. We further performed unsupervised hierarchical clustering for all glioma patients and compared survival between clusters.

RESULTS
Our results revealed that most GRGs were differentially expressed between non-tumor, IDHwt, and IDHmut gliomas. We found that gliomas grouped into 3 clusters based on the varying GRGs expression. Eighty-eight percent of glioblastomas (GBM, IDHwt) and 19% of all IDHmut tumors were characterized by low GRGs expression. These were denoted as cluster 1, and the remaining samples belonged to clusters 2 or 3, corresponding to intermediate and high GRGs expression groups, respectively. We performed survival analysis separately for IDHwt and IDHmut gliomas and found that cluster 1 patients had the worst prognosis, regardless of IDH status. We further separated IDHmut gliomas according to 1p/19q codeletion status. Oligodendroglioma (1p/19q codeleted) patients had a median survival of 33.2 months, 134.3 months, and 169.8 months in clusters 1, 2, and 3, respectively. No cluster-dependent differences in survival were seen for astrocytoma. For IDHwt (GBM) we found that patients from clusters 1 and 2 had survival of 14 months and 25 months, respectively. Due to the small number of deceased GBM patients in cluster 3, we could not estimate the median survival. The univariate analysis confirmed that cluster membership was an independent predictor of survival in oligodendroglioma (cluster 2 and 3 vs. 1, HR 0.14; 95% CI, 0.05-0.4; p=0.0005) and GBM (cluster 1 vs. 2 and 3, HR 3.05; 95% CI, 1.5-5.9; p=0.0012).

CONCLUSION
The GRG signature could define metabolic groups with distinct survivals in oligodendroglioma and GBM and constitute a new prognostic factor. We are planning further investigations to confirm our findings.
P10.19.A COMBINED TREATMENT USING MAPK AND PI3K SIGNALING PATHWAYS INHIBITORS EFFECTIVELY REDUCES GROWTH OF MELANOMA BRAIN METASTASIS CELLS IN VITRO
Authors: Sættem M , Wang J , Sundstrøm T , Thorsen F 
Published: September 2023

Abstract

BACKGROUND
Brain metastasis is associated with poor prognosis, and median survival time from the time of diagnosis for cancer patients with brain metastases is only a few months. Brain metastases are estimated to occur in 20-40% of cancer patients. All solid tumors may spread to the brain, but the risk of developing brain metastases is higher in breast cancer, lung cancer and melanoma. Standard treatment of melanoma brain metastases (MBM) includes radiation therapy and surgery. In melanoma, the mitogen activated protein kinase (MAPK) and the phosphoinositide 3-kinase (PI3K) signaling pathways are often activated by genetic alterations. An activation mutation (BRAFV600E) in the MAPK pathway is commonly found in melanoma refractory to therapy. This mutation leads to increased proliferation and tumor cell survival. Previous studies show that BRAF-inhibitors block the increase in cell proliferation induced by the activated BRAF gene, however, many of the patients develop drug resistance within a few months. Objectives: In this project, we aimed to show that drugs targeting BRAF (vemurafenib) and PI3K pathways (buparlisib) used in combination effectively inhibit growth of treatment resistant MBM cells.

MATERIAL AND METHODS
Our research lab has previously developed human MBM cell lines, which have been made resistant towards vemurafenib treatment. To study the potential antitumoral effects of combined treatment we used these cells in several in vitro assays such as cell viability and proliferation, cell migration, colony forming assay, spheroid growth, apoptosis by IncuCyte and western blot to confirm effects on signaling pathways.

RESULTS
We found that combination treatment reduced the viability of resistant MBM cells, as well as their ability to proliferate. Further, the cells showed less ability to migrate after therapy. Altered cell morphology was also seen. Initial results show effects on colony formation and increased apoptosis after combined treatment.

CONCLUSION
A combination of MAPK and PI3K inhibitors effectively inhibits growth and viability of treatment resistant human MBM cells, compared to single drug treatment alone. The results support clinical use of combined therapy for melanoma patients with metastatic disease.
P10.25.A ATR INHIBITION IN EXPERIMENTAL GLIOMA: DISCOVERY AND VALIDATION OF MOLECULAR TARGETS FOR FUNCTIONALLY-INSTRUCTED COMBINATION THERAPIES
Authors: Walter B , Hirsch S , Kuhlburger L , Stahl A , Schnabel L , Haeusser L A , Tsiami F , Ploeger S , Aghaallaei N , Dick A M , Skokowa J , Schmees C , Templin M , Schenke-Layland K , Tatagiba M , Nahnsen S , Merk D , Tabatabai G 
Published: September 2023

Abstract

BACKGROUND
The DNA damage response (DDR) is an important physiological network for the prevention of malignant transformation, e.g. by halting the cell cycle upon DNA damage detection and promoting DNA repair. Glioblastoma are incurable primary brain tumors that display acquired treatment resistance which might also be due to DDR dysregulation. Furthermore, we had recently investigated molecular effects of disrupting the (b)HLH network, a frequently altered and tumor-promoting transcriptional network in glioma. The identified downstream anti-tumor effects included the ataxia telangiectasia and Rad3 related (ATR) pathway. In the present study, we aimed at investigating the anti-glioma effects of ATR inhibition (ATRi) in experimental glioma and exploring potential treatment regimens for forward translation.

MATERIAL AND METHODS
We assessed ATRi monotherapy in the syngeneic SMA560/VM/Dk mouse model, performed acute cytotoxicity, clonogenic survival assays, cell cycle analyses by flow cytometry and apoptosis induction in vitro. Furthermore, we used RNA sequencing, DigiWest protein profiling analyses and genome-wide CRISPR/Cas9 loss-of function and activation screens. We evaluated synergistic or additive anti-glioma effects of functionally-instructed combination therapies by the Bliss and ZIP synergy models. We xenotransplanted zebrafish embryos with glioma cells to validate most promising combination approaches in vivo.

RESULTS
ATRi monotherapy induced prolonged latency until the onset of neurological symptoms in the SMA560/VM/Dk mouse model. ATRi reduced viability and clonogenic survival in vitro and ex vivo. Molecular analyses revealed differential patterns of gene expression, e.g. p53 signaling, differing modes of cell cycle and apoptosis regulation, arguing for a profound context specificity of the treatment. Similarly, CRISPR/Cas-9 genome-wide knockout and activation screens revealed distinct genetic vulnerabilities. Based on these

RESULTS
, we designed a drug library for investigating potential functionally-instructed modifiers of response to ATRi in experimental glioma in vitro, ex vivo and in vivo.

CONCLUSION
In summary, we present a workflow in experimental glioma for target discovery and validation leading to the design of novel combination therapies. We identify potential combination therapies involving ATRi in experimental glioma that could inform future early phase clinical trials and preclinical studies.
P10.35.A CDK12/CDK13 INHIBITION DISRUPTS A TRANSCRIPTIONAL PROGRAM CRITICAL FOR GLIOBLASTOMA SURVIVAL
Authors: Pandey D P 
Published: September 2023

Abstract

BACKGROUND
Glioblastoma is the most prevalent and aggressive malignant tumor of the central nervous system. Aberrant transcriptional programs are key to development and maintenance of cancer cells, and these can be exploited to target a specific cancer. Thus, targeting the transcriptional addiction specific for gliomas could offer a large therapeutic potential.

METHODS
A panel of patient-derived primary glioma stem cell (GSC) lines and glioblastoma organoids (GBO) were used to investigate the effect of transcriptional cyclin-dependent kinase (tCDK) inhibitors using a range of survival assays. A CRISPR/CAS9-based competition assay was applied to study the effect of genetic ablation of individual tCDKs. CUT&RUN was utilized to generate the genome-wide maps of the total RNA polymerase II (RNAPII) and phosphorylated species, and SLAM-seq was used to identify changes in steady-state and nascent transcriptome. Cell cycle analyses were done using EdU incorporation to mark S-phase cells.

RESULTS
We show that pharmacological inhibition or genetic ablation of the tCDKs, CDK12 and CDK13, markedly reduces the in vitro proliferation of GSCs and of ex vivo glioblastoma organoids as well as migratory capacity of GSCs. Using a xenograft mouse model, we demonstrate that CDK12/13 inhibition reduces tumor growth in vivo, which compares favorably with the existing chemotherapeutic treatments. Mechanistically, inhibition of CDK12/CDK13 leads to a genome-wide abrogation of RNAPII C-terminal Domain (CTD) phosphorylation, which in turn disrupts transcription and cell cycle progression in glioblastoma cells.

CONCLUSION
s CDK12/CDK13 inhibition may have a large therapeutic potential for glioblastoma treatment, both alone and in combination.
P11.08.B R-MPV THERAPY FOR PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA; SINGLE CENTER RETROSPECTIVE ANALYSIS
Authors: Nagashima H , Tanaka K , Yamanishi S , Sasayama T 
Published: September 2023

Abstract

BACKGROUND
Whole brain radiation therapy (WBRT) to primary central nervous system lymphoma (PCNSL) correlate with brain atrophy and leukoencephalopathy, negatively impacting cognitive function and quality of life. R-MPV with reduced WBRT or without WBRT has recently been reported to improve the outcomes of PCNSL. Here we retrospectively analyzed newly diagnosed PCNSL patients to compare the outcome and toxicity of R-MPV therapy with these of WBRT following R-MTX therapy in a real-life setting.

MATERIAL AND METHODS
Sixty newly histological diagnosed PCNSL patients were retrospectively evaluated. Clinical data from the database included patient characteristics, response rate, adverse effects, overall survival and radiological brain atrophy at 1 year; whole brain volume (mm2) calculated from BainLab automatically. Thirty-one patients were received WBRT (30Gy) following R-MTX therapy (R-MTX-RT group) and 29 patients were received R-MPV therapy (R-MPV group).

RESULTS
The mean age at symptom onset was significantly younger in R-MTX-RT group than in R-MPV group (64 vs 74 years, p=0.014). Complete response rate after chemotherapy was higher in R-MPV group (58% in R-MTX-RT group and 88% in R-MPV group). However, overall survival was not significant difference (53.5 month in R-MTX-RT group, 52.7 month in R-MPV group). Three patients of 31 (9.6%) in R-MTX-RT group and 6 patients (20%) in R-MPV group were not able to complete the chemotherapy regimen. Notably, patients &gt;75 years of age sometimes had severe adverse effect with R-MPV therapy. Treatment rerated death was not significant difference in both group (3% in R-MTX-RT vs 13% in R-MPV group, Fisher’s exact test p=0.19). Brain atrophy at 1 year was significantly lesser in R-MPV group than in R-MTX-RT group (R-MTX group, n=17; 4.03%, R-MPV group, n=15; 0.95%, p=0.005).

CONCLUSION
R-MPV therapy has benefit of avoiding WBRT in PCNSL patients. However, elderly patients exhibit increased risk for adverse events of R-MPV.