bluuebunny/crossref_metadata_2025 huggingface dataset:
P03.16.A ROLE OF BRD9 IN REGULATING RADIOTHERAPY INDUCED CHANGES IN CHROMATIN ARCHITECTURE OF GBM
Authors: Celikkol S A , Pinarbasi-Değirmenci N , Bagci-Onder T
Published: September 2023

Glioblastoma (GBM) is the most common, formidable, and aggressive type of adult brain tumor, with a poor prognosis. The standard treatment strategies are surgical resection, followed by radiotherapy and accompanying chemotherapy. However, 90% of patients suffer from recurrence of the disease due to the radiation resistance and chemotherapy resistance of glioblastoma cells, which exacerbate the success of the treatment, and thus, resistance remains one of the most important obstacles to overcome. The advances in molecular biology revealed that therapy resistance is related with alterations in DNA repair pathways as well as epigenetic changes governed by histone modifications and chromatin remodeling. Therefore, understanding the underlying epigenetic mechanisms that are involved in the DNA damage response has the potential to develop effective therapeutic strategies. In this manner, an epigenetic drug screen is conducted to identify novel epigenetic modifiers and their inhibitors as radiosensitizers. Bromodomain containing 9 (BRD9) was selected as target modifier while iBRD9 is selected as the radiosensitizer. Inhibition of BRD9 with a common probe, iBRD9 reduced cell viability and colony formation when combined with different doses of radiotherapy. Also, as an acetylated histone reader, inhibition of BRD9 increased the number of acetylated histones as shown by Western Blotting; where Belinostat treatment served as positive control. Currently, our efforts are directed towards understanding which genes are directly targeted by BRD9 in the presence and absence of radiotherapy. To this end, we have ectopically expressed Flag-tagged BRD9 and confirmed its expression by Western Blots. We showed that BRD9 was mainly localized to nucleus. Using this tool, we will perform ChIP sequencing and reveal radiotherapy induced changes in BRD9 binding sites.
P04.04.A GENOME-WIDE CRISPR/CAS9 KNOCKOUT SCREENS REVEAL EPIGENETIC REGULATORS AS DRUGGABLE TARGETS FOR SONIC HEDGEHOG MEDULLOBLASTOMA
Authors: Tsiami F , Piccioni F , Root D , Bandopadhayhay P , Segal R , Tabatabai G , Merk D
Published: September 2023

BACKGROUND

Sonic hedgehog medulloblastoma (SHH-MB) is a malignant pediatric brain tumor that accounts for 30% of all MBs and is characterized by constitutive activation of the SHH signaling pathway. Besides the standard-of-care therapies, current therapies are targeting Smoothened (SMO) receptor, in order to inhibit the pathway. However, acquired or de novo resistance against SMO inhibition limits its efficacy. Therefore, our aim is to unravel novel therapeutic targets for SHH-MB, potentially beyond the SHH pathway.

MATERIAL AND METHODS

We performed genome-wide CRISPR/Cas9 knockout screens, in order to decipher cancer dependencies and synthetic lethal interactors for SHH-MB. The hits identified were first validated genetically and pharmacologically in in vitro assays, while further molecular analyses including RNAseq and differential methylation were also conducted. Moreover, the identified hits were evaluated in in vivo mouse models representing normal cerebellar, as well as SHH-MB development.

RESULTS

Functional genomics identified members of the epigenetic machinery, such as Dnmt1 and Smarca5 as context-specific dependencies for SHH-MB. We prove that DNMT1 inhibition is efficacious against SMO-resistant and sensitive SHH-MB cell lines, by inhibiting SHH pathway output, as shown via RNAseq. A further knockout drug screen unraveled novel synthetic lethal interactors for DNMT1 inhibitors. Genetic ablation and pharmacological inhibition of epigenetic regulators prolongs survival of established mouse models of SHH-MB.

CONCLUSION

Summarizing, our data indicate inhibitors of epigenetic regulators as novel therapeutic targets for SHH-MB irrespective of mutational drivers within the SHH pathway. We further propose combinatorial treatment approaches for this tumor entity that involve DNMT1 inhibitors.
P04.10.A ASSESSMENT OF VDR STATUS BY IMMUNOHISTOCHEMISTRY IN CHILDHOOD MALIGNANCIES - VDR EXPRESSION PATTERN OF CNS TUMORS
Authors: Juhász O
Published: September 2023

BACKGROUND

Childhood cancers, including CNS tumors, the second most prevalent entities after hematological malignancies cannot generally be prevented or identified through screening, the disease is often diagnosed at advanced stages, and this obviously affects patient outcomes negatively. There is an urgent need for identifying prognostic and therapeutic biomarkers. Our previous work has shown a correlation between lower vitamin D levels in children with cancer and adverse prognosis. VDR expression in childhood solid tumors has been linked to tumor characteristics and patient survival only in few studies, moreover literature found that VDR plays a role in the development of the central nervous system.

METHODS

For this study, 177 children with solid tumors were selected whose biopsies and tumor tissue formalin-fixed, paraffin-embedded tissue blocks were available for immunohistochemical (IHC) analysis at Semmelweis University, Budapest (Hungary). To investigate the association between the presence of VDR in the tumor tissue and outcome, tumor samples and the survival dataset of 110 children were available.

RESULTS

We found that minor VDR expression was associated with a significantly less favorable prognosis (p = 0.0061) in the examined childhood solid tumors. The rate of VDR expression differed significantly between tumor types (p <0.0001). In case of CNS tumors pathological observations on VDR expression characteristics partly not correlated with previous literature. In some ependymoma samples an utterly novel VDR pattern was observed.

CONCLUSION

In conclusion, VDR expression measured by IHC staining is inversely associated with aggressive characteristics in different childhood cancers. The downregulation of VDR expression in more aggressive childhood cancers suggests that functional vitamin D activity may slow or block cancer progression. The presence of VDR may have prognostic and therapeutic implications for CNS malignancies. Knowledge of the VDR status in childhood solid tumors provides clinicians with a valuable biomarker and based on this, additional therapy (vitamin D, and analogs) to use alongside conventional first-line oncotherapy.
P05.01.B PROGNOSTIC MARKERS OF DNA METHYLATION AND NGS SEQUENCING IN PROGRESSIVE GLIOBLASTOMA FROM THE EORTC-26101 TRIAL
Authors: Kessler T , Schrimpf D , Doerner L , Hai L , Kaulen L , Ito J , van den Bent M , Taphoorn M , Brandes A A , Idbaih A , Domont J , Clement P M , Campone M , Bendszus M , von Deimling A , Sahm F , Platten M , Wick W , Wick A
Published: September 2023

BACKGROUND

The EORTC-26101 study was a randomized phase 2 and 3 clinical trial of bevacizumab in combination with lomustine versus lomustine alone in progressive glioblastoma. Other than for progression-free survival (PFS), there was no benefit from addition of bevacizumab for overall survival (OS). However, molecular data allows for the rare opportunity to assess prognostic biomarkers from primary surgery for their impact in progressive glioblastoma.

MATERIAL AND METHODS

We analyzed DNA methylation array data and panel sequencing from 170 genes of 380 tumor samples of the EORTC-26101 study. These patients were comparable to the overall study cohort in regards of baseline characteristics, study treatment and survival.

RESULTS

295/380 (78%) of patients’ samples were classified into one of the main glioblastoma groups receptor tyrosine kinase (RTK)1, RTK2 and mesenchymal. There were 10 patients (2.6%) with isocitrate dehydrogenase (IDH) mutant tumors in the biomarker cohort. Patients with RTK1 and RTK2 classified tumors had lower median OS compared to mesenchymal (7.6 vs. 9.2 vs. 10.5 months). O6-methylguanine DNA-methyltransferase (MGMT) promotor methylation was prognostic for PFS and OS. Neurofibromin (NF)1 mutations were predictive of response to bevacizumab treatment.

CONCLUSION

Thorough molecular classification is important for brain tumor clinical trial inclusion and evaluation. MGMT promoter methylation and RTK1 classifier assignment were prognostic in progressive glioblastoma. NF1 mutation may be a predictive biomarker for bevacizumab treatment.
P05.03.B METHYLOME PROFILING OF GLIOBLASTOMAS WITH FGFR3/TACC3 FUSION
Authors: Picca A , Gareau T , Mohand Oumoussa B , Carpentier C , Dridi-Aloulou A , Di Stefano A , Mokhtari K , Bielle F , Sanson M
Published: September 2023

BACKGROUND

Glioblastomas (GBMs) with the FGFR3-TACC3 (F3T3) gene fusion have histological, molecular, metabolic, and clinicoradiological characteristics. They have a better prognosis compared to other GBMs. Recent findings suggest that methylome profiling could further stratify these patients identifying a subgroup (defined as “outlier” F3T3+ GBMs, or GBM-F3T3-O) with a methylation profile resembling gangliogliomas (GGs), low-grade histological appearance, and a better outcome.

MATERIAL AND METHODS

We performed DNA methylation profiling (Infinium MethylationEPIC Array v1.0) of 32 adult diffuse gliomas with FGFR3 gene fusions (30 FGFR3-TACC3, one FGFR3-ACLY, and one FGFR3-MYO18A), plus two paired samples of a diffuse glioma with two distinct contingents (one with positive FGFR3 staining and FGFR3-TACC3 gene fusion, the other with intense EGFR staining and EGFR gene amplification). All cases corresponded to “glioblastoma, IDH-wildtype” according to the WHO CNS5. Methylation data were submitted to the DFKZ brain tumor classifier (molecularneuropathology.org), versions 11b4 and 12.5 and to dimensionality reduction with t-distributed stochastic neighbor embedding (tSNE). Copy-number variation (CNV) estimation based on conumee package was obtained from DFKZ website.

RESULTS

With the brain tumor classifier v11b4, most cases (26/34, 76%) were classified as methylation class (MC) GBM (17/26 with a significant score ≥0.9). Out of them, 23/26 (88%) were significantly (score ≥0.5) classified in the “GBM, mesenchymal” (16/26, 62%) or in the “GBM, RTK II” methylation families (7/26, 27%). With the classifier v12.5, again most tumors were classified as “GBM, mesenchymal” (18/34, 53%) or “GBM, RTK II” (9/34, 26%), of which twelve (12/34, 35%) with a score ≥0.9. Two were classifed as GG (score 0.69 and 0.39), both having “GBM, mesenchymal” as a second hit (score 0.19 and 0.33, respectively). Five had GG as a second hit, although with low scores (range <0.01-0.25). After tSNE dimensionality reduction of our and literature cases, most tumors clustered together with other GBM, mesenchymal and GBM, RTK II cases. Only two cases fell within a distinct cluster corresponding to GBM-F3T3-O tumors from the literature. These included two histologically defined GBMs with a survival of 26 and 100 months. Recurrent inferred CNV included chromosome (chr) 7 gain (96%) and chr10 loss (85%), followed by chr20 gain (46%), chr22q loss (46%), and chr19 gain (33%). The presence of chr19 gain (alone or associated with chr20 gain) was associated with increased survival (p=0.01).

CONCLUSION

Glioblastomas with FGFR3 fusions (mostly F3T3) have an epigenomic profile close to other mesenchymal and RTK II GBMs. Methylation analysis identifies methylation (GBM-F3T3-O) and CNV (chr19 gain) profiles associated with better survival.
P06.04.B NEW APPROACHES FOR EXPANDING GLIOBLASTOMA INFILTRATING LYMPHOCYTES
Authors: Khasraw M , Hotchkiss K , Blandford E , Mohan A , Railton C , Brown M , Noldner P , Zhou Y , Parrott R , Fecci P , Antonia S , Patel A , Shaz B
Published: September 2023

BACKGROUND

Adoptive cell therapy using tumor infiltrating lymphocytes (TILs) has shown promise in melanoma and Non-Small Cell Lung Cancer. TILs culture and expansion from GBM remains challenging due to paucity of infiltrated T-cells that are also exhausted. This hinders creation of potent TILs. We have developed a new efficient method to manufacture potent TILs from GBM samples.

METHODS

We have developed efficient TILs manufacturing methods using both solid and aspirated liquid samples collected during vacuum assisted excision containing tumor fragments that may stem predominantly from the tumor margins and provide a source for TILs. We followed the traditional two steps: initial expansion (preREP) where T-cells are expanded with tumor cells to selectively expand tumor antigen-reactive TILs, followed by a large-scale expansion (REP) after further activation. For both steps we optimized media and reagents.

RESULTS

TILs cultures from solid tumors were established from enzymatically digested tissue and by fragment plating. Successful TILs yield from liquid samples required enzymatic digestion, debris removal and RBC lysis prior to culture initiation. PreREP TILs yields ranged from a few million to 2 billion viable cells for solid and liquid samples. REP of TILs from liquid samples expanded similarly from solid samples. REP of TILs reached up to 556-fold expansion (mean: 346, range: 95-556) providing promising numbers of activated TILs. The potency of the TILs was demonstrated with tumor specific Interferon-gamma production when cultured with matched tumor digest or neurospheres.

CONCLUSIONS

We successfully expanded TILs that are rich in cytotoxic T-cells, demonstrated their tumor reactivity and further expanded the preREP TILs to reach therapeutic doses. We have characterized the TILs by scRNA and TCRseq and analyze paired TCR reads using scRNA sequencing. Overrepresented TCR alpha and beta chains will be linked by a P2A site and will be cloned into a lentiviral vector to establish a TCR library which will be transduced into novel Jurkat Triple Parameter Reporter Cell Lines under the control of different T cell activation programs. TCR Jurkat Libraries will be cocultured with original tumor material and sorted to identify tumor reactive TCRs; enabling us to define the percentage of TCRs that are enriched by TIL isolation that are specifically reactive to tumor vs bystander expanded TCR cells. Ultimately, we aim to bring this therapy to patients in a clinical trial.
P06.15.B IMMUNOTHERAPEUTIC TARGETING OF FIBROBLAST ACTIVATION PROTEIN (FAP) IN TREATMENT REFRACTORY GLIOBLASTOMA USING NOVEL CAR-T CELL THERAPY
Authors: Tatari N , Mohamed Seid Hedad H , Zingg A , Bartoszek E M , Tschan V , Schenker T , Ritz M , Miletic P , Venugopal C , Etter M , Singh S K , Läubli H , Hutter G
Published: September 2023

BACKGROUND

Glioblastoma (GBM) is the most common malignant primary adult brain tumor, characterized by extensive cellular and genetic heterogeneity. The Standard of Care (SOC) therapy and clinical trials have not been successful in improving patients’ survival which underscores an urgent need for developing new effective therapies for this treatment refractory disease.

MATERIAL AND METHODS

In silico and in vitro analysis have revealed high level of Fibroblast Activation Protein (FAP) expression in GBM tissue in multiple cell populations including endothelial cells, fibroblasts, stromal cells and tumor cells, but not on normal brain tissue, making FAP a safe and suitable therapeutic target as it allows for destruction of tumor cells as well as effective elimination of their supporting microenvironment. As Chimeric antigen receptor (CAR) expressing T cells have shown promising results against multiple cancers in the past few years, we aimed to target FAP in GBM by FAP specific CAR-T cells generated using a novel GMP-ready FAP-CAR construct produced based on a virus-free CAR gene transfer using advanced sleeping beauty transposon technology and preclinically test their anti-tumor efficacy against GBM at in vitro and in vivo level.

RESULTS

Our data revealed that co-culturing CAR-T cells with FAP+ GBM cells (U87) results in increased surface expression of T-cell activation markers. Moreover, FAP CAR-T mediated cytotoxicity against FAP+ GBM cells was also observed in the co-culture of GBM and CAR-T cells. For further validation, the effect of FAP CAR-T cells will be tested on patient-derived GBM organoids. The in vivo efficacy of FAP CAR-T cells is currently under investigation and we anticipate that the treatment of GBM tumor-bearing mice with FAP CAR-Ts results in extended survival and reductions of tumor burden.

CONCLUSION

These rigorously obtained data show high level of efficacy for FAP-specific CAR-T cells against GBM suggesting that clinical development of this therapeutic modality can provide a novel therapeutic strategy for GBM patients that can be used in combination with SOC or other immunotherapeutics. Therefore, upon successful completion of the preclinical study, we plan to conduct a phase I dose-escalation trial of autologous FAP-CAR T cells for patients with recurrent Glioblastoma.
P07.02.B A FATTY-ACID BASED PROBE FOR NEAR INFRARED FLUORESCENCE GUIDED SURGERY OF GLIOBLASTOMA
Authors: Ali M , Khodakivskyi P , Goun E , Lamfers M L M , Lowik C W G M , Dirven C M F , Balvers R K , Mezzanotte L
Published: September 2023

BACKGROUND

Glioblastoma (GBM) is the most aggressive primary tumor of the brain with a median survival of 15 months. Maximal safe resection is the initial standard-of-care, but resection is limited by the diffuse invasiveness of the tumor. Fluorescence imaging has been shown to aid intra-operative tumor identification, but the current options fail to do so consistently. Recent literature has shown fatty acid (FA) metabolism and uptake to be altered in glioblastoma. For this reason, we introduce a novel, near-infrared fluorescent dye, fatty-acid indocyanine green (FA-ICG), that aims to target the enhanced fatty acid uptake of glioblastoma. We evaluate this dye in in vitro and in vivo models.

MATERIAL AND METHODS

FA-ICG consists of palmitic acid, a long-chain, saturated fatty acid, that has been covalently linked to indocyanine green (ICG), as described previously. We validated FA-ICG in vitro in one animal cell line and four (two primary and two recurrent) patient-derived neurosphere glioblastoma cell lines. We performed in vitro temporal uptake dynamics and oleic acid based inhibition assays for FA-ICG and ICG on all cell lines. Time uptake was investigated by starving and then incubating cells with either dye for an increasing length of time. Similarly, inhibition was tested by incubating cells with increasing concentrations of oleic acid (in addition to either FA-ICG or ICG). Subsequently, the dye was tested in an NRMI mouse model without tumor for pharmacokinetic properties. Mice were injected with the dye and blood was collected at multiple time points post-injection. Quantification of fluorescence signals in serum was performed using a fluorescent standard curve.

RESULTS

FA-ICG was taken up by all glioblastoma cells lines. Across all cell cultures, uptake of FA-ICG showed a stepwise increase of up to 5-30 times higher uptake (compared to uptake at baseline) when cells were starved longer, while ICG uptake showed the same trend in only three out of five cell lines (and only up to 5 times higher uptake than at baseline). Oleic acid was found to inhibit FA-ICG uptake by 40% at low concentrations and up to 80-90% at higher concentrations across all cell lines, while ICG was unaffected. In vivo pharmacokinetics showed FA-ICG to have a mean half-life of 65 minutes in blood.

CONCLUSION

Our findings indicate that the uptake of FA-ICG is affected by starvation and oleic acid competition across all cell lines while ICG uptake is only partially affected by starvation. In vivo pharmacokinetic shows the half-life of FA-ICG to be significantly longer than that of ICG in literature. Taken together, these findings might point to an enhanced targeting and retention mechanism of FA-ICG in glioblastoma. Therefore, these results support the further translation of FA-ICG for fluorescence guided surgery in GBM.
P08.01.A FAMILY SUPPORT NEEDS IN GLIOBLASTOMA - FROM RELATIVES’ PERSPECTIVES
Authors: Ståhl P , Henoch I , Smits A , Rydenhag B , Ozanne A
Published: September 2023

BACKGROUND

Glioblastoma is the most common and aggressive brain tumour in adults. In spite of standard treatment by surgery followed by radiation and chemotherapy, the average life expectancy is only 10-15 months. As such, glioblastoma affects the family situation and relatives around the patient need support. There is a lack of knowledge about their experiences of support during the illness. The aim of this study was to investigate support needs during the illness trajectory in glioblastoma from the relatives’ perspectives.

MATERIAL AND METHODS

In this study, 12 relatives (7 partners, 3 children, 1 sister, 1 friend) to patients with a histologically-confirmed diagnosis of IDH-wt glioblastoma since at least 2 months and age ≥ 18 years at the time of diagnosis, were interviewed individually based on a semi-structured interview guide. Interviews took place on one occasion by physical or digital meeting or via telephone, based on the participant's preferences. The interviews were audio recorded and transcribed verbatim. Data collection occurred from March 2022 until December 2022. The analysis using inductive qualitative content analysis is in progress.

RESULTS

Preliminary results show that relatives were mostly satisfied with the support from the health care. However, they lived in a very stressful situation and parts of the support could be better organized. It was important for them with clear and correct information regardless of the outcome. The waiting time before and after MRI, living in limbo with anxiety of what would be found, was particularly stressful and they desired processing with faster answers. Availability to the health care was an important factor and because of the difficult situation they preferred digital meetings instead of physical meetings. Further, they found it difficult to manage the contacts with different health care instances and thought it would be helpful with support to navigate them to correct instance.

CONCLUSION

The preliminary results indicate that support to the families should be more structured och focused on clearness, high availability and openness for the family’s needs, and guidance in the health care system.
P08.07.B TRANSITION CLINIC IN NEURO-ONCOLOGY WHICH MODEL IS BETTER? THE PATIENT'S OPINION
Authors: Azuelos A , Haisraely O , Atar N , Jan E , Taliansky A
Published: September 2023

BACKGROUND

The period between adolescence and adulthood is important and complicated for all people. Is much more complicated for young adults (YA) that were diagnosed and treated for central nervous system (CNS) tumors in childhood and adolescence. They have to continue a lifelong multidisciplinary surveillance that is time and energy consuming. Patients that does not have any or significant neurological deficit desire to start a ”normal” to age life that includes independence from the parents and reduction of hours spent in the hospital. They try to undergo surveillance in community health services but that way is complicated and the surveillance is made irregularly or not at all. If they undergo surveillance in hospitals where it is regularly made, the patients lose school or work days and suffer from high anxiety level because of the “to be a patient again ” feeling . Attempts to create the optimal surveillance model for those patients were made, but the best model is still unknown.

MATERIAL AND METHODS

We questioned CNS tumor patients 20-40 years old that were transferred from a pediatric to an adult neuro-oncology service in Sheba MC.

RESULTS

The response from 38 patients was obtained: 11 patients with pilocytic astrocytomas, 11 other gliomas, 3 gangliogliomas, 2 germ cell tumors, 3 medulloblastomas, 3 NF1 patients with optic pathway gliomas, 4 with pineal region tumors, 1 with immature teratoma. 33% of patients are married and live with the spouse, 55% live with their parents, 4 % live by themselves. Of the respondents 18 % are students and 47% are permanently employed. Most of the patients prefer to undergo surveillances in community health services and visit hospitals as rare as possible. All patients expressed an understanding of the importance of a lifelong surveillance as recommend by the treating neuro-oncologist. The patients strongly expressed the need to have a dedicated case coordinator that can help organize the test’s flexible timetable and an effective communication between the teams

CONCLUSION

According to our patient’s opinion, the preferable model of surveillance for high functioning YA CNS tumor patients is the cooperation of the hospital’s neuro-oncology unit and the community health service. The first is responsible for planning the surveillance and taking the appropriate medical actions according to the

RESULTS

. The second is responsible for the realization of the program. The assignment of a case coordinator that connects between all of the teams is crucial.
P08.10.B COIMBRA: THE IMPACT OF RADIOTHERAPY ON QUALITY OF LIFE AND DISEASE PROGRESSION IN PATIENTS WITH BRAIN METASTASES AND THEIR CAREGIVERS
Authors: Cialdella F , van Grinsven E E , van der Boog A T J , Nagtegaal S H J , Smid E J , Claes A , Kleynen C E , Seravalli E , Philippens M E P , van Zandvoort M J E , Verhoeff J J C
Published: September 2023

INTRODUCTION

Brain metastases (BMs) are diagnosed in 10-30% of all cancer patients, and this incidence is expected to rise due to advancements in primary tumor management. Besides improving survival, the impact of treatment on quality of life (QoL) and course of disease is highly relevant for patients and their caregivers. The Cohort for patient-reported Outcomes, Imaging and trial inclusion in Metastatic BRAin disease (COIMBRA) study aims to gather data on natural disease progression, treatment response, tumor recurrence, complications, QoL (for both patient and caregiver), cognitive performance and survival of patients with BMs. Additionally, the study evaluates feasibility, performance and added value of new MRI techniques in patients with BMs, while providing an infrastructure for efficient and pragmatic randomized evaluation of new interventions. DESIGN/

METHODS

The prospective COIMBRA study is designed to monitor a cohort of patients with BMs and their caregivers who are referred to a tertiary academic radiation oncology department (ClinicalTrials.gov Identifier: NCT05267158). The study is designed according to the Trials within Cohorts (TwiCs) framework, an adaptive design that allows for the evaluation of multiple interventions over time. Patients receive state of the art treatment, which includes stereotactic radiosurgery (SRS) or whole brain radiotherapy (WBRT). Clinical data, QoL and cognitive functioning are collected at baseline and at regular intervals post-treatment. Additionally, new MRI techniques can be evaluated for their feasibility and performance in patients with BMs. PRELIMINARY

RESULTS

Since April 2019, 419 patients have been included of whom 51.2% were men and the majority of the patients had lung cancer (53.6%). SRS was administered in 92.4% and 68.1% received systemic therapy. Median overall survival was 18.3 months. Questionnaires available at both baseline and 6 months after radiotherapy showed that 65.3% experienced stability or improvement in QoL measured via the EORTC QLQ-C30 questionnaire. Fewer patients reported anxiety or depression after SRS compared to before treatment (28.4% vs 47.8%). Caregivers’ baseline responses indicated that 59% had to adjust their daily lives due to the patients’ diagnosis.

CONCLUSION

Our study successfully collected in-depth clinical and QoL data from patients with BMs and their caregivers. The results suggest a modest improvement in anxiety and QoL after SRS. These findings highlight the need for ongoing evaluation of interventions in this patient population in order to ultimately guide personalized treatment strategies.
P09.04.B PNES IN BRAIN TUMOR PATIENTS : AN UNEXPECTED CHALLENGE
Authors: Loebenstein R , Eltity M , Magiel E , Haisraely O , Noga A , Jan E , Boxer M , Taliansky A
Published: September 2023

BACKGROUND

Epileptic seizures (ES) are common in brain tumor patients. The phenomenon of psychogenic non-epileptic seizures (PNES) amongst those patients has not been well described. PNES Phenomenology could be similar to ES, however, epileptogenic activity on electro-encephalogram (EEG) is absent. The diagnosis of PNES can be challenging in brain tumor patients since both types of seizures can present with similar symptoms and might occur together. Risk factors for the development of PNES include a history of negative events in childhood, exposure to trauma, history of psychiatric illness and chronic pain, and substance abuse. Diagnosing PNES is important for delivering the appropriate treatment, and preventing the toxic influence of unneeded treatment and procedures.

MATERIAL AND METHODS

The Electronic files of patients with ES and PNES were evaluated, in A retrospective analysis from the database of the Neuro-Oncology unit at Sheba Medical-Center.

RESULTS

4 patients with brain tumor related epilepsy and PNES were identified: a female 22 years old with right frontal IDH1 mutated non 1p/19q deleted glioma WHO2, a 44 years old male with right frontal IDH1 mutated 1p/19q deleted glioma WHO2, a 48 years old female with left temporo-insular IDH1 mutated non 1p/19q deleted glioma WHO2 and a 65 years old female with multiple radiation induced meningiomas. Seizures semiology were compatible with the lesions. The first two patients had recent stress factors, and the last two suffered severe diagnosis-related anxiety. All patients presented initially with ES and developed PNES subsequently. They were treated with 2-4 Anti-Epileptic drugs(AED’s). They were referred to EEG video monitoring due to worsening seizures frequency despite increasing the AED’s and no evidence of tumor progression at that time. All patients had clinical seizures which did not have any epileptiform activity correlation on Video-EEG. Hence, PNES was diagnosed. Three patients underwent psychological treatment and two patients received medical therapy for underlying psychological factors contributing to PNES. Seizure frequency and number of AED's decreased in all patients.

CONCLUSION

In patients with brain tumors the diagnosis of PNES can be challenging but should be considered in patients with increased seizures frequency regardless of stable imaging and absence of any other provocative factors. Video EEG is pivotal for PNES diagnosis. Psychological consulting and treatment are recommended in PNES cases. Correct diagnosis and treatment will contribute to the patient's quality of life.
P09.05.A IMPACT OF A 16-WEEK SUPERVISED EXERCISE INTERVENTION ON CANCER-RELATED FATIGUE IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA UNDERGOING ADJUVANT CHEMOTHERAPY
Authors: Jost J , Kloss M S , Brandt R , Völker K , Stummer W , Wiewrodt R G , Wiewrodt D
Published: September 2023

BACKGROUND

Cancer-related fatigue (CRF) is considered one of the most prevalent symptoms in brain tumor patients undergoing concurrent chemoradiation (approx. 80 % of those affected). Several studies have identified beneficial effects of physical activity on reducing CRF. However, few studies have examined the reduction of CRF by exercise in glioma patients. Here we present prospective data showing the effect of an intensive 16-week supervised exercise intervention on CRF in neuro-oncological patients.

MATERIAL AND METHODS

Between July 2020 and April 2023, patients with newly diagnosed glioblastoma and after surgery and concomitant radiochemotherapy have been recruited for this single-arm trial in progress. Participants have received a 16-week supervised training intervention on a 1:1-basis consisting of two intensive 50-minute sessions per week (bicycle ergometry at an average of 75 % of maximum heart rate and progressive whole-body resistance training). CRF has been assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ C30). We calculated change scores (scores: 0-100; 100=max. fatigue) from baseline, after 8 weeks, and post-intervention (week 16).

RESULTS

So far, 26 glioblastoma patients (13 women) aged 35-84 years (mean 59 years) participated in the exercise intervention. All patients received adjuvant chemotherapy (50 % Stupp, 42 % CeTeG, 8 % other). Paired t-test indicated a statistically significant reduction in CRF from baseline to post-intervention (p=.030; 95 % CI: -0.5 - 24.2). Mean scores reduced from 40.4 to 36.2 (week 8) to 26.9 (week 16). However, the decrease between week 0 and week 8 was not yet significant (p=.281; 95 % CI: -7.6 - 13.6).

CONCLUSION

The present trial shows that a 16-week supervised exercise program can reduce CRF in glioblastoma patients despite adjuvant chemotherapy. Thus, and consistent with studies of exercise interventions in patients of other tumor types, glioblastoma patients have the opportunity to actively contribute to the reduction of tumor- and therapy-induced side effects through intensive physical training.
P09.12.B EFFECT OF TRADITIONAL CHINESE MEDICINE (TCM) AND WESTERN NATUROPATHY ON PATIENTS WITH GLIOBLASTOMA
Authors: Goldbrunner R , Roth-Goldbrunner S , Timmer M , Nettekoven C , Kochs S
Published: September 2023

BACKGROUND

IDH wildtype Glioblastoma (GBM) is an aggressive brain tumor with dismal prognosis. Current efforts focus on integration of supportive therapies like psychooncology and palliative care in routine care. Traditional Chinese Medicine (TCM) and western naturopathy are integrative modalities that have been studied recently for managing various symptoms and diseases. Aim of this study was to assess effects of TCM and western naturopathy on symptom burden relief and survival of glioblastoma patients.

METHODS

In this retrospective study we performed a matched pair analysis comparing 21 GBM patients with a combined treatment comprising standard radio chemotherapy plus TCM and western naturopathy (TCM group) with matched control patients receiving standard radiochemotherapy alone (control group). Matching was done according to age, gender, IDH status, MGMT methylation status and KPS. Statistical analysis was performed using GraphPad Prism 9.

RESULTS

The patient in the TCM group felt better regarding their general condition and had less symptom burden. Moreover, progression free survival (PFS) was significantly longer in the TCM group (17.4 +/- 12.2 months) compared to the control group (12.6 +/- 6.9 months; p < 0.01). Overall survival increased from 20.5 +/- 8.5 (control group) to 25.0 +/- 14.5 months (TCM group, n.s.).

CONCLUSION

Glioblastoma patients seem to benefit significantly from additional integrative medicine including TCM and western naturopathy , both, in terms of symptom relieve and regarding progression free survival. However, a prospective randomized trial with a larger patient cohort would be necessary in order to confirm this effect.
P10.04.B LONGITUDINAL [18F ]FET-PET-BASED IMAGING AND PROFILING OF PDGFB-DRIVEN EXPERIMENTAL GLIOMA USING THE RCAS-TVA SYSTEM
Authors: Becker H , Castaneda-Vega S , Patzwaldt K , Przystal J M , Walter B , Michelotti F C , Canjuga D , Tatagiba M , Pichler B , Beck S C , Holland E C , la Fougère C , Tabatabai G
Published: September 2023

BACKGROUND

Glioblastoma are aggressive and incurable primary tumors of the central nervous system. As patients present with already established tumors, longitudinal imaging by MRI and [18F]FET-PET in human glioblastoma for characterizing temporal and spatial metabolic alterations is only possible to characterize alterations during therapy, but not during tumor evolution. In this regard, genetically engineered preclinical models are very relevant. The replication-competent avian sarcoma-leukosis virus (RCAS)/tumor virus receptor-A (tva) system provides a high grade of spatial and temporal control of somatic gene delivery in vivo. In this study, we used longitudinal MRI and [18F]FET-PET to characterize the evolution and growth of platelet-derived growth factor B (PDGFB)-driven glioma model using the RCAS-tva system.

MATERIAL AND METHODS

DF-1 cells transfected with PDGFB were implanted into adult 129S.Tg(NES-TVA)-Cdkn2a−/− mice intracranially. Mice received MRI twice and [18F]FET-PET measurements once per week. Longitudinal growth pattern and [18F]FET-PET uptake were assessed and analyzed. We measured symptom-free survival and performed immunohistochemistry on collected tumor tissue samples.

RESULTS

We observed robust tumor formation with highly reproducible symptom-free survival times of treatment-naïve experimental animals. Contrast-enhanced MRI volumetry revealed exponential growth dynamics starting around day 25 after DF-1 inoculation. Here, the PDGFB-driven gliomas present an escalating [18F]FET-PET uptake as well as increasing BBB permeability over time. These imaging features match the clinical scenario, which underlines the translational relevance of this model. Histology corroborated the imaging findings and an immunogenic glioma-associated microenvironment.

CONCLUSION

These data provide further valuable insights into this RCAS/tva-based PDGFB-driven murine glioma model and advocates for an imaging-stratified design of preclinical therapeutic interventions.
P10.11.A CHARACTERISTICS OF DIFFUSE MIDLINE GLIOMA WITH H3 K27M MUTATION IN ADULTS
Authors: Tanaka K , Nagashima H , Yamanishi S , Itoh T , Sasayama T
Published: September 2023

BACKGROUND

H3 K27M-mutant diffuse midline gliomas (DMG) occur primarily in children but can also be encountered in adults. Adult H3 K27M-mutant DMG is a still challenging disease with no effective medical therapies.

MATERIAL AND METHODS

We retrospectively analyzed the characteristics and prognostic factors of 49 adult patients with intracranial midline gliomas treated in Kobe University Hospital from 2006 to 2022.

RESULTS

The median age at diagnosis in midline gliomas was 50.8 years (range: 17-83 y). All tumors were located in thalamus n=25, brainstem n=10, cerebellum n=14. Isocitrate dehydrogenase 1 (IDH1) and H3 K27M mutation was recognized in 6 and 16 patients, respectively, which was mutually exclusive. In all midline gliomas, the identification of H3 K27M mutation was significantly a poor prognosis factor (median 18.5 months vs 34.2 months, p=0.041). Among IDH1 wild-type midline gliomas, however, H3 K27M-mutant DMG had no worse overall survival (median 18.8 months vs 22.2 months, p=0.805).

CONCLUSION

H3 K27M-mutant DMG is considered as a distinct WHO Grade 4 regardless of histological features, but the biological properties of H3 K27M mutation is not yet defined in IDH1 wild-type midline gliomas in adults.
P10.24.B SCREENING NON-ONCOLOGICAL DRUGS IN A PATIENT-DERIVED GLIOBLASTOMA MODEL IDENTIFIES PITAVASTATIN WITH POTENTIAL ANTITUMOR ACTIVITY
Authors: Zekanovic S , Achaiber Sing P , Basuki A , Koolen S L W , Ntafoulis I , den Hollander C W J , Chien M P , Li Y , Mustafa D A M , Dirven C M F , Leenstra S , Lamfers M L M
Published: September 2023

BACKGROUND

Glioblastoma (GBM) is a malignancy which is in dire need of novel treatment options. Repurposing non-oncological drugs has become of great interest in GBM research. Non-oncological drugs have many advantages over their oncological counterparts including a well-established safety and toxicity profile, possibilities to perform dose escalation studies, and combinations with oncological drugs (e.g. temozolomide, TMZ). Making use of our patient-derived in vitro model which has been shown to recapitulate GBM in terms of genetic make-up and heterogeneity, we aim at identifying non-oncological drugs that exhibit potent antitumor activity.

MATERIAL AND METHODS

Drug screening was performed using an NIH clinical compound selection consisting of 446 non-oncological drugs on 2 patient-derived GBM cell lines. Viability 5 days post treatment was assessed using the ATP-based Cell Titer Glo assay. Validation studies were performed on a panel of 25 GBM cultures. Nanostring analysis using the Pan Cancer gene panel, flow cytometry, Western Blotting and immunofluorescence were employed to gain insight into drug mechanism of action. The zero-interaction potential method was used to quantify synergy with TMZ. Dose-modifying factors (DMF) were calculated to quantify synergy with irradiation.

RESULTS

Screening of 446 non-oncological drugs yielded a top 10 list of candidates which were evaluated on an additional cell panel. Based on safety and efficacy, pitavastatin, an HMG-CoA reductase inhibitor, was selected for further analysis. Compared to 8 other registered statins, pitavastatin revealed the most potent anti-tumor activity, with IC50 values in the low micromolar range. Pitavastatin efficacy was validated in a panel of 25 GBM cultures derived from various GBM subtypes in terms of primary/recurrence, MGMT and IDH status (IC50 ranging from 0.1 - 5.0 µM). GBM cultures derived from patients using statins for cholesterol management did not reveal resistance to pitavastatin. Combination treatment of pitavastatin with either TMZ or irradiation showed synergy with TMZ in 5/8 cultures and radiosensitizing effects in 3/5 cultures (DMF >2.0). Importantly, no antagonism was observed with TMZ or irradiation. Mechanistic studies demonstrated that pitavastatin treatment led to induction of autophagy, perturbations in GBM cell cycle and attenuation of GSC stemness through downregulation of SOX2 and CD133.

CONCLUSION

Drug screening on patient derived GBM cultures identified pitavastatin as a potent inhibitor of GBM cell viability and revealed its chemo- and radiosensitizing effects. Mechanistic studies suggest that its antitumor effects could be a consequence of autophagy induction, cell cycle arrest and loss of GBM cell stemness. Currently we are exploring strategies to ensure optimal intratumoral delivery in vivo.
P10.27.A THE INFLUENCE OF DEXAMETHASONE ON TOTAL DNA METHYLATION LEVEL IN GLIOBLASTOMA CELL LINES
Authors: Barciszewska A , Belter A , Giel-Pietraszuk M , Gawrońska I , Naskręt-Barciszewska M
Published: September 2023

BACKGROUND

Dexamethasone (DEX) is a first-line antiedematic drug for glioblastoma (GBM) patients. There is also some evidence it also inhibits GBM cell proliferation and migration, thus impacting patients’ outcomes. However, other studies show that the use of DEX is associated with poor treatment outcomes in GBM patients. The exact mechanism of DEX action is unclear, and no definitive conclusion has yet been reached on its benefits in neurooncological treatment. Temozolomide (TMZ) is a first-line chemotherapeutic in GBM. Epigenetics offers a connection between genetic and environmental factors that influence the development of the disease. The best-characterized epigenetic mark is 5-methylcytosine (m5C) in DNA. The aim of that project is to show the effects of DEX administration on the total DNA methylation level.

MATERIAL AND METHODS

Using the nucleotide post-labeling method, we analyzed the total amount of m5C in DNA of GBM (T98G, U118, U138), cancer (HeLa) and normal (HaCaT) cell lines treated with DEX, and a combination of DEX and with TMZ.

RESULTS

We adjusted the DEX doses to the ones achieved in the central nervous system during treatment. We observed dose-dependent increase in total DNA methylation in all cell lines. However, the exposition of GBM cells to the combination of DEX and TMZ caused an adverse synergistic effect resulting in DNA demethylation in high doses of both drugs. In lower concentrations of both drugs DEX kept the increased DNA methylation and attenuated the demethylating effect of TMZ.

CONCLUSION

Total DNA methylation changes in glioma cell lines under DEX treatment suggest the new mechanism of that drug action and promote clinical implications for adjusting DEX and TMZ therapy in GBM patients. Our results show the potential and possible obstacles of the combined therapy of TMZ with DEX. Our experiments show that combined therapy with both drugs leads to total DNA hypomethylation in high doses of both drugs. Therefore the conclusion would be to adjust DEX administration during TMZ chemotherapy.
P10.33.A TARGETED INHIBITION OF THREE MAJOR PROLIFERATION PATHWAYS IN GLIOBLASTOMA INDUCES SENESCENCE THROUGH A MITOCHONDRIA-DEPENDENT MECHANISM
Authors: Baltira C , Mayayo-Peralta I , Guillén-Navarro M , Thijssen B , Alkan F , Pello K , Fedorushkova D M , Their A , Silva J , Jochems F , Bleijerveld O , Janssen H , Faller W J , Bernards R , de Gooijer M C , van Tellingen O
Published: September 2023

BACKGROUND

Glioblastoma (GBM) is a fatal brain tumor with a great unmet need for better therapies. Research on the genomic landscape of GBM has revealed that three major proliferation pathways — the PI3K-mTOR-AKT, the MAPK, and the CDK4/6-RB pathways — are overactive in the majority of GBM patients. Based on that knowledge we have developed a multi-target combination therapy (MTCT) by employing inhibitors of these three pathways. When these inhibitors are used in combination, lower, clinically more relevant concentrations of each drug are sufficient for target inhibition and proliferation arrest than with single agents.Excitingly, we find that MTCT not only shuts down proliferation but also causes permanent growth inhibition by the induction of senescence and the secretion of a senescence-associated secretory phenotype (SASP).

MATERIAL AND METHODS

Senescence is identified in a multimodal way, including morphological characterization, SASP production, beta-galactosidase activity, and colony outgrowth potential. RNAseq together with (phospho)proteomics are also applied to investigate the molecular mechanism in combination with techniques such as DNA damage assays, flow cytometry, western blot, metabolic assays, and fluorescence microscopy.

RESULTS

MTCT-senescent cells have increased mitochondrial reactive oxygen species (mtROS). However, they do not acquire nuclear DNA damage but only local mitochondrial DNA damage. Addition of antioxidants that deplete mtROS resulted in senescence rescue both in terms of morphology and proliferation arrest. MTCT-senescent cells display an enhancement in total mitochondrial mass, mitochondrial DNA copy numbers, and the transcription of mitochondrial proteins. Despite this enhancement, the basal respiration rate of these cells is comparable to untreated cells, indicating an impaired maximal respiration capacity in MTCT-senescent cells. Concordantly, these cells display striking disturbances of their mitochondrial network.Intriguingly, depletion of functional mitochondria prevents the induction of mtROS and senescence by MTCT but not by classical senescence inducers such as ionizing radiation or high concentrations of CDK4/6 inhibitors.

CONCLUSION

MTCT induces senescence in GBM cells through a unique nuclear DNA damage-independent mechanism for which the mitochondria are essential.