bluuebunny/crossref_metadata_2025 huggingface dataset:
OS06.7.A SOMATOSTATIN RECEPTOR SUBTYPE EXPRESSION AND RADIOMICS FROM DWI-MRI REPRESENT STANDARDIZED UPTAKE VALUES (SUV) OF68GA-DOTATOC PET IN PATIENTS WITH MENINGIOMA, A TRANSLATIONAL STUDY
Authors: Iglseder S , Iglseder A , Beliveau V , Heugenhauser J , Gizewski E , Kerschbaumer J , Stockhammer G , Uprimny C , Virgolini I , Dudas J , Nevinny-Stickel M , Nowosielski M , Scherfler C
Published: September 2023

BACKGROUND

In this translational study, we first aimed to analyse the expression of somatostatin receptor subtype (SSTR) 2A, 2B and 5 and their correlation with the maximum standardized uptake value (SUVmax) of 68Gallium DOTA-D-Phe1-Tyr3-octreotide Positron Emission Tomography (68Ga-DOTATOC PET) in patients with meningioma. Secondly, we aimed to develop a radiomic model based on apparent diffusion coefficient (ADC) maps derived from diffusion weighted magnetic resonance images (DWI MRI) to reproduce SUVmax.

MATERIAL AND METHODS

A total of 51 patients who underwent MRI and 68Ga-DOTATOC PET prior to surgical resection of intracranial meningioma were included in the imaging part of the study. SUVmax were quantified from the PET images. Segmentation of the post-contrast T1-weighted (cT1) MR images served as regions of interest and were mapped to the co-registered ADC maps. A total of 1940 radiomic features were quantified from the tumor area for each ADC map. A random forest regression model was trained to reproduce SUVmax values. The model was evaluated within a repeated nested cross-validation design. The training included a feature selection was done in two-steps using a minimum redundancy maximum relevance feature selection and a recursive feature elimination based. The expression of SSTR subtypes 2A, 2B and 5 was quantified in 18 surgical specimen of meningioma and compared to SUVmax values.

RESULTS

The SUVmax values predicted by the random forest models correlated significantly with the observed values (p < 0.05) for all 100 repeats with a mean Pearson’s r = 0.42 ± 0.07 SD and a RMSE = 28.46 ± 0.16. The expression of SSTR subtypes 2A, 2B and 5 correlated significantly with the SUVmax values (p<0.001, R2=0.669; p=0.001, R2=0.393; and p=0.012, R2=0.235, respectively).

CONCLUSION

In this translational study, SSTR subtypes 2A, 2B and 5 correlate significantly with SUVmax. We developed a random forest regression model using radiomic features to reproduce SUVmax from 68Ga-DOTATOC PET in meningiomas.
OS08.7.A DEPRESSIVE SYMPTOMS IN ASSOCIATION WITH TUMOR LOCATIONS AT DIAGNOSIS IN PATIENTS WITH DIFFUSE GLIOMA
Authors: van Genderen* M N G , Belgers* V , Douw L , Barkhof F , Klein M , Niers J M , Eijgelaar R S , de Witt Hamer P C
Published: September 2023

BACKROUND

Depressive symptoms are common in glioma patients and occur more frequent than in patients with other cancer types. The presence of tumors in specific brain regions that potentially disturb brain functions could contribute to this difference. These lesions may cause an inadequate emotional response to an incurable and lethal disease with consequences for patient counseling and neurosurgical strategies. In this study, we examine the association between brain tumor location and depressive symptoms at presentation in patients with diffuse glioma using several methods for lesion symptom mapping.

MATERIAL AND METHODS

The retrospective cohort consisted of patients with diffuse glioma who had a preoperative MR-scan and completed the Center for Epidemiologic Studies Depression scale (CES-D) before treatment. We classified patients based on unexpectedly low ( ≤6), intermediate (7-20) and unexpectedly high (>20) CES-D scores. Tumors were segmented in 3D and corresponding white matter disconnectomes were derived from normative tractography. We first correlated tumor and disconnectome with CES-D using sparse canonical correlation analysis to identify clusters of associated brain voxels. Next, we assessed the association between tumor locations and CES-D category using Bayesian multivariable categorical regression analysis of patient and tumor characteristics, including the overlap of tumors and disconnectomes with specific brain atlas structures, the probability of disconnection of white matter tracts, and functional network changes in local efficiency and eigenvector centrality.

RESULTS

We included 201 patients with a median age of 45 years (range 18-81), consisting of 62% males and 29% grade 4 gliomas. CES-D was completed a median of three weeks before surgery, was unexpectedly low in 29% and unexpectedly high in 15% of patients. Tumors located in the left (L) pallidum and right (R) thalamus were related to unexpectedly low CES-D, whereas tumors in the L hippocampus, L nucleus accumbens and R putamen were related to unexpectedly high CES-D. Disconnection of the R temporal subsection of the cingulum bundle, L optic radiation, L superior longitudinal fasciculus I and L uncinate fasciculus (UF) were related to unexpectedly low CES-D, whereas disconnection of the R corticospinal tract, R fornix, and L UF were related to unexpectedly high CES-D. Neither voxel clusters nor network measures were associated with CES-D.

CONCLUSION

Both unexpectedly low and unexpectedly high depressive symptom burden is common in patients with diffuse glioma at presentation. These dysfunctional emotional responses may be associated with the location of the tumor. Awareness of this phenomenon may be important in patient counseling and neurosurgical strategies.

* these authors contributed equally
OS10.5.A PERIVASCULAR CONTAINED T CELLS IN IDH-MUTANT ASTROCYTOMA CO-LOCALIZE WITH GEMISTOCYTIC TUMOR CELLS OF AN ASTROCYTE-STATE AND MACROPHAGES WITH AN IMMUNE-STIMULATORY PHENOTYPE
Authors: van Hijfte L , Geurts M , de Heer I , Vallentgoed W R , Balcioglu H E , Debets R , French P
Published: September 2023

BACKGROUND

Isocitrate dehydrogenase mutant (IDHmt) astrocytoma is considered a T cell excluded tumor, yet little is known regarding the underlying cues that may drive T cell exclusion. To aid better understanding of this mechanism in IDHmt astrocytoma, we systematically characterized the immune microenvironment of this tumor type.

METHODS

We performed and analyzed multiplex immunofluorescence stainings for lymphocytes, myeloid cells and IDH1-R132H of 1293 regions from 75 IDHmt astrocytomas. We consequently performed bulk, single nucleus and spatial RNA sequencing of samples from the same cohort. Integrative analysis of data from these platforms allowed for the identification of unique tumor and immune cell subsets that are crucial in the spatial organization of the immune microenvironment and T cell containment in IDHmt astrocytoma.

RESULTS

IDHmt astrocytoma showed three spatially distinct distribution patterns of T cells: regions with perivascular accumulation of T cells, regions with T cells in the tumor stroma and T cell absent regions. Perivascular accumulation of T cells, known as T-cell cuffs, was the most abundant pattern in our data. Spatially, there was a significant increase of tumor cells around T cell cuffs that showed a gemistocytic phenotype, a tumor cell type that is histologically characterized by a large eosinophilic cytoplasm and ectopically localized nucleus. Gemistocyte-high tumors (> 20% of all tumor cells) demonstrated enhanced expression of genes related to immune cell migration and activation that were reliably expressed by tumor associated macrophages and T cells. Notably, gemistocytic tumor cells were identified as a distinct sub-cluster of the ‘astrocyte-like’ transcriptomic cell state with a phenotype that is linked to astrogliosis and expressed CD44, TNC and TGFB2. Moreover, gemistocytic tumor cells were spatially associated with a CD83+ subpopulation of tumor-associated macrophages that resemble reactive microglia in astrogliosis and show increased expression of the chemo-attractants CCL3, CCL4 and CCL4L2.

CONCLUSION

Using different modalities for spatial and single cell profiling of RNA and protein, we uncovered a previously unknown relationship between the immune system and tumor cells in IDHmt astrocytoma. We found that gemistocytic tumor cells showing an ‘astrocyte-like’ state co-occur with perivascular contained T cells and immune-stimulatory macrophages in IDHmt astrocytomas. The transcriptional profiles of these tumor cell subsets and macrophages point towards a CNS specific defense mechanism of glial cells associated with T cell exclusion.
OS13.6.A SURVIVAL IS ASSOCIATED WITH CIRCULATING B-CELLS AND AGE AMONG OLIGODENDROGLIOMA PATIENTS
Authors: Taylor J W , Warrier G , Hansen H , McCoy L , Rice T , Guerra G , Francis S , Clarke J , Bracci P , Kelsey K , Wrensch M , Molinaro A , Wiencke J
Published: September 2023

BACKGROUND

Though patients with oligodendroglioma have improved outcomes versus astrocytomas, there remains marked variability in their survival experience that is unexplained by known prognostic factors. Immunomethylomics uses DNA methylation as a substitute for flow cytometry to characterize immune cells in whole blood. We applied immunomethylomics to archived samples from patients with oligodendroglioma enrolled in the UCSF Adult Glioma Study (AGS) to assess the impact of immune-related characteristics on prognosis.

MATERIAL AND METHODS

We used immunomethylomics to evaluate immune cell fractions in archived whole blood from the AGS. We identified 141 patients with oligodendroglioma (IDH and TERT mutant, and 1p19q co-deleted) and compared them to other adult diffuse glioma subtypes (N = 347) and controls (N = 454).

RESULTS

The median age at diagnosis of the 141 oligodendrogliomas was 44 years (range 19 - 83), 57% were male, and 75% white. A total of 60% of patients had received chemotherapy, with or without radiation, prior to blood draw and 25% were taking dexamethasone at the time of sample collection. Oligodendroglioma patients had lower proportions of B cell fractions (total, memory, naïve) than people without glioma. Still, there were higher proportions of B cell (total, memory) and lymphocyte fractions (total, CD4-total and memory), basophil, eosinophil, and NK cells in oligodendrogliomas compared to other glioma subtypes. Median overall survival for the oligodendrogliomas was 17.5 years (95% CI 16.9 - NA) with median follow-up time of 12 years (95% CI 11 - 14). Recursive partitioning analysis delineated two statistically significantly different survival groups for oligodendroglioma patients based on an interaction between age at diagnosis and B naïve cell proportions. The group with the best outcome had a median survival of 24.2 years (95% CI 20.4 - NR) comprised of patients </= 42 years of age with a higher proportion of B naïve cells (>1.91%) (N = 37). The group with the worse outcome had a median survival of 16.9 years (14.8 - NR) and included patients </= 42 years of age with a lower proportion of B naïve cells (</= 1.91%) (N = 28) OR patients > 42 years of age (N = 76) (p = 0.00032). Additionally, proportions of lymphocyte fractions (CD4 and CD8 total, memory, and naïve) were significantly lower in the worse outcome group. Grade or prior treatment did not differ between the groups.

CONCLUSION

We identified an interaction between age and B naïve cell proportions that distinguished survival outcomes for patients with oligodendrogliomas. Immunomethylomics is a powerful tool for assessing immune status and these findings suggest that blood-immune characteristics may play a vital role in the prognosis of patients with gliomas.
P02.03.A INTEGRATIVE (EPI)GENETIC ANALYSIS OF INVASION-PROMOTING GENES IN HIGH-GRADE GLIOMA CELLS
Authors: Müller T , Mittelbronn M , Hau A
Published: September 2023

BACKGROUND

DNA methylation-based analyses of brain tumors including glioma is currently the gold standard for diagnostic classification. Aberrant epigenetic alterations can lead to inappropriate gene expression and thereby promote tumorigenesis. Glioblastoma (GBM), CNS WHO grade 4, is characterized by a very diffuse infiltrative growth into the adjacent brain parenchyma. Due to these highly invasive but also genetically heterogeneous and plastic cellular phenotypes, standard treatment, including maximum resection, radio- and chemotherapy, has limited efficacy. It can be assumed that intertumoral or molecular heterogeneity of gliomas on transcriptional level is caused by altered epigenetic changes within the individual tumor cells. Considering this, we hypothesize that tumor cell invasion being one of the critical hallmarks of highly malignant gliomas goes along with altered DNA methylation status and following from this changes in invasion-promoting transcript expression.

MATERIAL AND METHODS

We performed several in vitro screening approaches to describe the genetic, epigenetic and transcriptional status of invasion glioma cells. Within our first approach, we isolated fractions of glioma cells with increased invasive properties and performed Illumina® array-based methylation profiling as well as RNA sequencing analysis to identify methylation-driven, invasion-associated gene sets. During a second approach, the inducible CRISPR/Cas9 Synergistic Activation Mediator (SAM) system and a genome-wide sgRNA library were introduced in a serum-free glioma cell line. During CRISPR/Cas9 SAM mediated single-gene activation cells were subjected to a transwell invasion assay and sgRNA representation within the invasive glioma cell fraction was determined by next-generation-sequencing (NGS).

RESULTS

In this study, we integrated Illumina HumanMethylation850K methylation data, RNA-sequencing data and invasion-promoting sgRNA representation data. By systemic screening we identified an invasion-promoting gene signature and the correlating promotor DNA-methylation status. Future studies will be directed to further investigate the impact of identified genes in invasion of high-grade glioma cells.

CONCLUSION

This integrative experimental approach complements existing genome-wide inhibitory screens as well as incorporates for the first time DNA-methylation profiles and transcriptome analysis with gene-sets identified by CRISPR/Cas9 activation screen and thereby holds the potential to identify novel invasion-essential candidate genes.
P02.08.B ROLE OF THE PROTEIN NETWORK OF THE PARACASPASE MALT1 IN SELF-RENEWAL PROPERTIES OF GLIOBLASTOMA CELLS
Authors: Kerhervé M , Gavard J
Published: September 2023

BACKGROUND

Glioblastoma is the most common and most aggressive brain tumor in adults. Despite standard treatment combining surgery, radiotherapy and chemotherapy, relapse is inevitable, making this cancer a major public health issue. Within this tumor reside cells with a stem-like character, called GSCs for Glioblastoma Stem-like Cells, which maintain, initiate, and propagate the tumor, making them a potential target to hinder glioblastoma. These cells constitute a reservoir of heterogeneous cells capable of differentiating into neural lineage cell types. In this context, lysosomal homeostasis plays a key role in the maintenance of the GSC reservoir. Furthermore, previous studies demonstrated that the paracaspase MALT1 is a major regulator of lysosomal homeostasis: MALT1 is required for GSC viability as well as for the maintenance of stemness by modulating the abundance of lysosomal proteins. This current study addresses the issue of the balance between self-renewal and viability of GSCs. In addition, this project aims to identify and characterize an actor of self-renewal mechanisms that does not impact the survival-death balance of primary cells from patients.

MATERIAL AND METHODS

An initial analysis combining DepMap and String Network databases allowed us to select potential relays of the MALT1 activity in GSCs. A functional screening was then set up and performed in GSCs derived from patients to identify among 20 candidates those regulating cell expansion without impacting viability.

RESULTS

The strategy of functional screening allowed the selection of 14 genes with a global viability effect, while only 2 genes were affecting self-renewal while sparing viability in vitro. We next pursued with one of the identified targets, from the IKK family. The involvement of this serine/threonine protein kinase was then confirmed in multiple patient cells and in CRISPR-mediated knock-out. Future experiments will decipher the involvement of this kinase in the self-renewal properties of GSCs.

CONCLUSION

This study highlights a putative candidate specifically operating on the self-renewal of glioblastoma cells, that does not affect the life-death balance. Future investigations will permit to characterize and understand the underlying mechanisms.
P02.19.A ASSESSMENT OF HEAT SHOCK PROTEIN HSP70 EXPRESSION IN THE GLIOBLASTOMA STEM-LIKE CELLS
Authors: Shevtsov M , Yudintceva N , Nechaeva A
Published: September 2023

BACKGROUND

Glioblastoma multiforme (GBM) is a malignant brain tumor characterized by poor prognosis. The search of biomarkers for early diagnosis and as targets and for tumor theranostics due to the aggressiveness of the disease is urgently needed. One of the promising targets for therapy of brain tumors is 70 kDa heat shock protein (Hsp70), which has been found on the plasma membrane of various tumor cells (including GBM) but not on normal cells. GBM, like other types of tumors, has cellular heterogeneity. In particular, it contains tumor stem-like cells (TSLCs), which are considered analogues of healthy stem cells and are largely responsible for disease progression, recurrence and mediate resistance to ongoing therapy. In the present work, the histological sections of human GBM were analyzed to identify and quantify the colocalization of the heat shock protein Hsp70 with TSLC markers using the Opal Multiplex analysis system.

MATERIAL AND METHODS

Histological sections were prepared in accordance with the standard protocol using postoperative material from patients with newly diagnosed GBM (n=15). Zones of necrosis and living tissue were identified on tumor sections. Based on a phenotyping map using the Pathology Views™ fluorescence image analysis software, Hsp70 colocalization was quantified with Nestin and Sox2 in the areas of necrosis and viable tissue employing primary antibodies (anti-Hsp70, anti-Nestin and anti-Sox2). The preparations were stained using an Opal 3-Plex Manual Detection Kit according to the manufacturer's protocol.

RESULTS

The expression of Hsp70 and TSLC markers (Nestin and Sox2) was detected. The obtained quantitative data did not reveal significant differences in the distribution of cells expressing Hsp70 in the areas of necrosis and viable tissue (36 and 41%, respectively), which may indicate their uniform distribution in the tumor. Sufficiently high colocalization of Hsp70 with Nestin and Sox2 factors was detected mainly in the zone of viable tissue (57 and 30%, respectively).

CONCLUSION

Colocalization of Hsp70 with TSLC markers indicates the prospects for further studies of Hsp70, as well as its use for targeted therapy of malignant brain tumors.
P03.10.A IDENTIFYING DNA DAMAGE RESPONSE (DDR) RELATED FACTORS ESSENTIAL FOR RADIOTHERAPY RESPONSE IN GLIOBLASTOMA USING A NOVEL CRISPR/CAS9 LIBRARY, DDRKOL
Authors: Kok I , Bayraktar C , Durgun A , Aksu A C , Kayabolen A , Yedier Bayram O , Sur Erdem I , Bagci Onder T
Published: September 2023

The standard treatment of glioblastoma, which is the most common and aggressive primary brain tumor, includes combined radiotherapy (IR) and chemotherapy (temozolomide (TMZ)) after surgery. The basic working principle behind radiotherapy is to induce DNA double-strand breaks (DSBs), which is the most lethal form of DNA damage and the primary cause of cell death, and to finally kill cancer cells. Additionally, exposure to IR induces the activation of a multicomponent signal transduction network of DNA damage response (DDR). In this study, we developed a new CRISPR/Cas9-based tool to investigate the role of DDR mechanisms and identify novel genes affecting radiotherapy response in glioblastoma. We generated a focused sgRNA library termed DDRKOL (DNA Damage Response Knock Out Library) targeting the DDR pathway to identify novel modulators of TMZ and radiotherapy response with CRISPR/Cas9 screening in vitro. DDRKOL includes a total of 9000 sgRNAs targeting 888 genes (10 sgRNA/gene) containing all DNA damage-related pathways, curated from Gene Ontology Consortium, 35 sgRNA positive controls targeting cell essential genes, 90 non-targeting control sgRNAs, and 35 internal control genes. The composition and coverage of the library were validated, and DDRKOL was utilized to investigate modulators of TMZ response in U87MG cells. Our future work will involve characterizing different effects of DDRKOL members in radiotherapy response, in different subtypes of gliomas with different genetic

BACKGROUND

s. Cell response to radiation is important, therefore optimization experiments were performed with different radiation doses in A172, U373, and U373-60Gy cell lines to choose the optimal dose suitable for screening. Accordingly, 2 Gy radiation was chosen for large-scale screens. DDRKOL will serve as an important tool to study not only glioblastoma but also many other diseases that threaten global health. Discovering novel genes that affect the therapy response will be stimulating because it will help understand how to overcome therapy resistance and develop new strategies to design effective therapeutic strategies, which can ultimately translate into clinics.This study is supported by TUBITAK 1001 program (#221S439).
P03.13.B RADIOTHERAPY-INDUCED COGNITIVE IMPAIRMENT IN CANCER PATIENTS: IS SENESCENCE INVOLVED?
Authors: Kuil L E , de Gooijer M C , van Heijningen C , Compter A , van Tellingen O , Schagen S B
Published: September 2023

BACKGROUND

Patients with primary and metastatic brain tumors that survive may experience cognitive problems including progressive impairments in memory, attention, and executive function attributed to radiation-induced brain injury. Irradiation is known to bring tumor cells into senescence, a state of permanent proliferation arrest that is accompanied by metabolic changes and a secretory phenotype, which may cause inflammation. We hypothesize that senescence in the healthy brain, caused by whole brain radiotherapy (WBRT), plays an important role in cognitive problems.

MATERIAL AND METHODS

In this pilot experiment the effect of three different dosages (12, 30 and 60 Gy) of fractionated WBRT was assessed at different intervals after irradiation using male C57BL/6JRj mice. We performed senescence associated β-glucosidase (SA-β-gal) staining, cytokine ELISA assays, RT-qPCRs and immunohistochemistry to identify cellular senescence in the healthy brain.

RESULTS

Unexpectedly, no clear indications of induced cellular senescence in the brain could be observed by assessing SA-β-gal, cytokines and senescence markers on RNA and protein level. However, we found persistent DNA damage foci, microglial activation, a reduction in oligodendrocyte precursor cells and neurogenesis in the subvertricular zone.

CONCLUSION

No clear evidence for cellular senescence after WBRT was detected in the mouse brain, whereas profound effects were found on glia, neurogenesis and DNA damage. Difficulties in detecting cellular senescence might be explained by differences in presence of so-called markers for cellular senescence in the brain, or the rare nature of senescence in vivo. In future studies neurobiological changes will be assessed at later time points after WBRT, using a senescence reporter mouse and will be combined with behavioral studies.
P06.01.A HAS THE USE OF DUAL AGENT IMMUNOTHERAPY BEEN ALTERING THE INCIDENCE OF MELANOMA BRAIN METASTASES? A POPULATION-LEVEL ANALYSIS AND SINGLE-INSTITUTION VALIDATION
Authors: Salmanian S , Bhanja D , Wilding H , Moeckel C , Hong J , Dao J , Baroz A , Stahl C , Sivik J , Drabick J , Pameijer C , Mansouri A
Published: September 2023

BACKGROUND

Dual agent immunotherapy (dIT) has revolutionized the treatment of advanced melanoma, with recent clinical trials demonstrating its effectiveness in managing small, asymptomatic melanoma brain metastases (MBM) in the upfront setting. However, its potential role in preventing MBM has not been thoroughly investigated.

MATERIAL AND METHODS

A retrospective analysis was performed on the TriNetX database, which compiles clinical data from 92 healthcare organizations. Melanoma patients without MBM at diagnosis were divided into two groups: those who received ipilimumab alone (single immunotherapy, sIT) and those who received ipilimumab and nivolumab (dIT). The study compared the frequency of new asynchronous MBM diagnosis among the cohorts and analyzed the median overall survival (OS) of MBM patients using Kaplan Meier analysis and log-rank tests. Additionally, a retrospective cohort validation study was conducted on a sample of randomly selected patients treated at a single institution between 2012-2019. Electronic medical records were reviewed for demographics, melanoma treatment history, and clinical outcomes.

RESULTS

TriNetX identified a total of 732,555 melanoma patients, including 717,408 who did not receive immunotherapy (no-IT), 4,585 who received dual immunotherapy (dIT), and 4,101 who received single immunotherapy (sIT). The mean ages at melanoma brain metastases (MBM) diagnosis were 66.9, 61.5, and 63.2 years for each respective group. The prevalence of MBM was 1.5%, 9.6%, and 15.6% for no-IT, dIT, and sIT groups, respectively (p < 0.0001). DIT was associated with a lower rate of MBM compared to sIT(OR [95%CI], 0.64 [0.61-0.77]). After propensity score matching, the median overall survival for MBM patients was not statistically different between the no-IT, dIT, and sIT groups (347, 400, 414 days, respectively). In the validation group of 90 patients (30 no-IT, 27 sIT, 34 dIT), predominantly male (61.5%), stage III (62.5%), the prevalence of MBM was 13.8%, 59%, and 38.2% for each respective group for developing MBM (OR [95%CI], 2.35 [0.84-6.60], p=0.08). The mean time between immunotherapy initiation and MBM was 305 days for dIT and 500 days for sIT for patients who developed MBM.

CONCLUSION

The results suggest that using a combination of ipilimumab and nivolumab immunotherapy could be effective in reducing the incidence of brain metastases in advanced melanoma patients. Further investigation is needed to explore the potential preventive role of dIT in MBM development in this patient population.
P06.16.A FRACTIONATED IRRADIATION ACTIVATES GLIOMA IMMUNE MICROENVIRONMENT AND BOOSTS ANTIGEN-SPECIFIC T CELL RESPONSE IN MALIGNANT GLIOMAS
Authors: Elmadany N , Michel J , Sonner J , Ovchinnikova S , Sanghvi K , Bernhardt I , Zhang X , Jähne K , Ott M , Sati A , Anders S , Breckwoldt M , Platten M , Sahm K
Published: September 2023

Several ongoing clinical trials employ vaccine, immune checkpoint inhibitors and/or adoptive T cell therapy to treat glioblastoma. However, the impact of irradiation as part of the standard of care on the immune microenvironment and response to immunotherapy is ill-defined. In the present study, we analyzed the post-irradiation changes in the GBM immune microenvironment, and further elucidated the impact of fractionated tumor irradiation (FIR) on the efficacy of T cell-mediated immunotherapies in experimental gliomas. FIR boosted the response of orthotopically-implanted GL261 tumors expressing the tumor-associated antigen glycoprotein (gp)100 to a gp100 vaccine. Furthermore, FIR enhanced the infiltration of GL261-gp100 gliomas by adoptively-transferred gp100 T cell receptor-transgenic T cells, which also displayed a more activated and less exhausted phenotype post-irradiation. Single cell transcriptomic studies of tumor-infiltrating CD45+ leukocytes revealed that FIR promotes the expression of leukocyte-endothelial adhesion molecules in T cells, and transcripts encoding proinflammatory M1-like genes in tumor-associated microglia and macrophages. Collectively, our preclinical findings support the use of FIR with to increase response to T cell-based immunotherapies.
P06.17.A OPTIC NEUROPATHY RELATED TO IMMUNE CHECKPOINT INHIBITORS: A CASE SERIES
Authors: Cuzzubbo S , Philippakis E , Baroudjian B , Ursu R , Lebbé C , Coutourier A , Carpentier A F
Published: September 2023

BACKGROUND

Immune checkpoint inhibitors (ICIs) are associated with a broad spectrum of neurotoxicities. ICI-related optic neuritis have been rarely reported and poorly described. However, their knowledge is essential to promptly recognise and manage them since a persisted visual decline is reported in approximately half of the patients. A systemic steroid treatment has been correlated to a better prognosis.

MATERIAL AND METHODS

We report a retrospective series of patients with an ICI-related optic neuritis, referred to our departments between 2018 and 2022, with the aim to describe their clinical and para-clinical features and the outcome. Other causes of optical neuropathy were excluded by blood analysis and brain MRI.

RESULTS

We identified three melanoma patients who developed an ICI-related optic neuropathy. They were treated with combined ipilimumab with nivolumab (n=2) or pembrolizumab monotherapy (n =1). The symptoms occurred after a delay of 43-196 days from ICI initiation and consisted of bilateral painless reduction of visual acuity, associated with colored scotomas in one case and conjunctival erythema in another case. Ophthalmological examination found a bilateral papilledema in all the patients, associated with a panuveitis in one case (patient #1). The presence of papilledema was verified by fundus fluorescein angiography and optic coherence tomography (OCT). Visual evoked potential confirmed a bilateral involvement of optical nerves in two cases, and was normal in the third case, which was thus consistent with a papillitis. ICIs were stopped in patients #1 and #2 and oral steroids started in patient #1. Both patients experienced a complete recovery within 2 weeks from steroids onset and 24 weeks from the last ICI dose, respectively. Given the quick and spontaneous improvement of both symptoms and ophthalmological exam, ICI was continued with the same regimen in patient #3, and the optic neuropathy progressively improved until complete recovery 3 months later. ICI treatment was reintroduced in patient #2 after four months, with no recurrence of the optical neuritis until the last follow up (5 years).

CONCLUSION

As reported in other series of immune-related optic neuropathies, a bilateral optic nerve involvement with painless decline of vision and papilledema was the most common presentation. Unlike other reports, all the patients of this series experienced a favorable outcome, with total recovery of vision and normalization of the ophthalmological exam. The recovery seems more rapid if patient receive steroids. We reintroduced or continued the ICI in two patients, with no recurrence of optic neuritis, thus suggesting that ICI treatment discontinuation is not mandatory in case of non-severe optical neuropathies. However, a careful analysis of the benefit/risk ratio should be done on a case-by-case basis.
P07.06.A PATIENT-DERIVED GLIOBLASTOMA MINIATURE AND CANCER STEM CELL SUICIDE-INDUCING NANO-AWAKENER BASED ON IT
Authors: Yoon S , Baek S , Yoo S , Jo E , Lee D , Shim J , Choi R , Park J , Moon J , Kim E , Chang J , Lee J , Park J , Sung H , Kang S
Published: September 2023

BACKGROUND

Patient-specific anti-tumor therapies can evolve by vitalizing the mother tissue-like cancer niche, cellular profile, genetic signature, and drug responsiveness. This evolution elucidated a key mechanism along with the development of the cancer therapy. The present study aimed to meet these clinical demands by approaching the direct culture of GBM patient tissues with a 1 mm post-punching diameter in a 3D microchannel network chip (“GBM miniature”).

MATERIAL AND METHODS

Hence, we directly cultured of GBM patient tissue (1 mm diameter) in a microchannel network chip (GBM miniature) to preserve mother tissue-like characteristic signatures and microenvironment. When chemoradiation therapy were administered within 1 day, the responsiveness of the tissue in the chip mirroring the clinical outcomes. The characteristics of migrating cells from GBM miniature were analyzed, and peptides that target these migrating CSCs were searched for. And, by attaching this CSC peptide to the nanovesicle, the therapeutic effect was confirmed in GBM miniature.

RESULTS

Upon testing within 1 day, the tissue chip reflected patient drug responsiveness as seen in the clinic. As the tissue chip culture was continued, the intact GBM signature was getting lost, and the outward migration of stem cells from the tissue origin increased, indicating a leaving-home effect on the family dismantle. Nanovesicle production using GBM stem cells enabled self-chasing of the cells that escaped the temozolomide effect owing to quiescence. The anti-PTPRZ1 peptide display and temozolomide loading to nanovesicles awaked stem cells from the quiescent stage to death.

CONCLUSION

This research proposes a GBM patient avatar platform and mechanism-learned nanotherapy for translation.
P07.08.A DEVISING AN EXOSOMES CONTROLLED-RELEASE HYDROGEL FOR GLIOBLASTOMA THERAPY
Authors: HE Z , Meng Z , Wang G
Published: September 2023

BACKGROUND

An efficient therapeutic method for glioblastoma hasn’t been founded. Nowadays, the combination of tumor surgery resection and chemoradiotherapy show limited outcomes even implanting a drug-loaded wafer on the tumor resection cavity during the surgery. Although Local drug delivery improves the adverse effects of intravenous chemotherapy drug injection, the low efficiency of drug transmembrane transportation still leads to poor therapeutic outcomes. Meanwhile, the stiff wafer is not able to perfectly match the irregular shape of the resection cavity. Recently, drug-loaded nanoparticles coated by tumor-derived exosomes applied in tumor-targeting drug delivery were frequently reported. The unique feature of tumor-homing, immune evasion of tumor-derived exosomes was used to improve the delivery efficiency, however, the therapeutic efficiency is weakened by liver filtration and the blood-brain barrier.

MATERIAL AND METHODS

For enhancing the therapeutic efficacy and compatibility of tumor resection cavity, in this project, a novel injectable hydrogel carrying DOX-loaded nanoparticles coated by tumor-derived exosomes, called Exo-DMSNs@CS, for intra-operative therapy of glioblastoma was devised. The doxorubicin-loaded nanoparticles encapsulated by tumor-derived exosomes (Exo-DMSNs) were integrated into body-temperature sensitive chitosan hydrogel, then injected into the tumor resection cavity and gelation along the shape. By passing the blood-brain barrier, the therapeutic efficacy can be improved by elevating the delivery efficiency induced by the released tumor-targeting Exo-DMSNs.

RESULTS

The hydrogel Exo-DMSNs@CS was successfully fabricated and contained features of thermosensitive, in vivo controlled releasing, in vitro tumor-targeting, and biocompatible. For simulating the scenario of intra-operative therapy, the Exo-DMSNs@CS was evaluated in the mice orthotopic GBM resection model. The decreased relapse speed and extended survival showed in the Exo-DMSNs@CS compared to DMSNs@CS demonstrated that the tumor-exosomes improve the prognosis of the mice. Moreover, the acceptable side effect was also confirmed.

CONCLUSION

The Eco-DMSNs@CS is suitable for therapy with better efficiency compared to traditional local drug delivery. This research provides a new strategy for glioblastoma patients and data support for similar product devising.
P08.03.A CAREGIVERS OF ADULT NEURO-ONCOLOGICAL PATIENTS: UNMET NEEDS AND RELEVANT PROBLEMS - A PROSPECTIVE STUDY
Authors: Spieker M , Rapp M , Rieger D , Bombach P , Kurz S , Tatagiba M , Sabel M , Tabatabai G , Renovanz M
Published: September 2023

BACKGROUND

The diagnosis of a brain tumor represents high burden for patients’ caregivers. Psychosocial screening tools for caregivers adapted to neuro-oncological tumor entities are urgently required but do not exist. To bridge this gap, we aim to develop a problem list in terms of a holistic need assessment tailored to their unmet needs of caregivers for an application in combination to the NCCN distress thermometer scale.

MATERIAL AND METHODS

First, items of high relevance for the caregivers were identified on basis of retrospective analyses. Second, we prospectively conducted an assessment in two centers: in the first center, caregivers filled out a questionnaire (center A), in the second center, the questionnaire was applied as qualitative interview with caregivers (center B). We performed a qualitative content analysis applying inductive/deductive categorizations of the reports.

RESULTS

The qualitative interviews included n=11 main questions and up to 4 subquestions focusing on changes in everyday life, relationship, social live, emotional, physical, financial, spiritual problems and support needs. A total of 47 caregivers were assessed (n=25 in center A via questionnaire, n=22 in center B via interviews) during outpatient visits. Most of the caregivers wished for psychological support (27/47, 57%), first contact with psycho-oncologists after first diagnosis (25/47, 53%) or in case of a clinical deterioration (28/47, 59%). Strategies for problem solving (26/47, 55%) and finding sources of strength (22/47, 47%) were most important regarding needed support. Changes in everyday life’ were reported by 87% of caregivers (41/47), including constraints/organization of (medical) appointments (24/47, 51%) or constant availability required for the partner (20/47, 43%). Also, 70% (33/47) put their own interests last or adapt their leisure activities. In the qualitative interviews (Center B), additional items indicating caregiver burden were identified: “dealing with psychological problems of the patient” (3/22, 16%), “different coping strategies among patient and caregiver” (4/22, 18%). Emotional problems, particularly depressive symptoms were addressed more profoundly in the qualitative interviews (“loss of interest and feelings of sadness”, 4/22, 18%).

CONCLUSION

The interviews reflected the unmet needs of brain tumor caregivers and allow for the targeted assessment of the specific burdens. Furthermore, we were able to gather more in-depth information per qualitative interviews.
P09.02.B THE RELATIONSHIP BETWEEN SYMPTOMS AND THE SOCIAL DETERMINANTS OF HEALTH AMONG THE PRIMARY BRAIN TUMOR POPULATION: A SYSTEMATIC REVIEW
Authors: Stockdill M L , Johnson M , Karim Z , Cooper D , Armstrong T S , King A L
Published: September 2023

BACKGROUND

Social determinants of health (SDoH) account for up to half of all health outcomes in the general population, but their impact on symptoms is less understood, especially in rare cancers such as primary brain tumors (PBT).

MATERIAL AND METHODS

We reviewed the literature and examined the relationship between SDoH and mood and neurocognitive symptoms in the PBT population. PubMed, EMBASE, and CINAHL identified 3,006 publications. SDoH were defined using PROGRESS criteria (Place of residence, Race/ethnicity, Occupation, Gender, Religion, Education, Socioeconomic status, Social capital). Two individuals screened and assessed study bias.

RESULTS

Of 3,006 abstracts identified, 150 full text articles were assessed for eligibility and 48 studies were included with a total sample of 28,454 PBT participants. 27 studies were cross-sectional with the majority from single institutions in the US (12), Germany (10), or Netherlands (5). Sample sizes varied from 27 to 15,320. 22 studies examined the relationship with 1 of the PROGRESS categories and no study examined all 8. 4 studies measured place of residence, 2 race/ethnicity, 13 occupation, 43 gender, 1 religion, 18 education, 4 socioeconomic status, and 15 social capital. 37 studies reported on mood related symptoms with 20 focused on depression, 14 anxiety, and 11 distress. 15 studies assessed neurocognitive symptoms, while 4 assessed both mood and neurocognition. Among studies assessing neurocognition, 1 found a relationship with place of residence and socioeconomic status, 7 out of 10 reported a relationship with education, and 7 of 11 found no relationship with gender. None examined race/ethnicity or religion. Disparate results were found related to occupation. Among the 37 studies assessing mood, results were disparate except for place of residence, which related rural residence to depressive symptoms. Bias assessment revealed that 61% of the studies were fair in quality, 31% poor, and 8% good indicating the majority of studies had evidence of bias.

CONCLUSION

Most studies were descriptive or exploratory and lacked comprehensive inclusion of SDoH, which limited the opportunity to perform meta-analysis. This is the first systematic review examining the relationship of symptoms in the PBT population and SDoH to date. Future studies should use standardized collection of SDoH, reduce study bias, and encourage inclusion of diverse samples to identify gaps for the development of future interventions.
P10.01.A A PATIENT-DERIVEDEX VIVO ORGANOID MODEL ALLOWS EVALUATION OF TUMOR TREATING FIELDS (TTFIELDS) EFFECTS ON GLIOBLASTOMA, ANAPLASTIC EPENDYMOMA AND OLIGODENDROGLIOMA SAMPLES
Authors: Nickl V , Schulz E , Salvador E , Trautmann L , Diener L , Kessler A F , Monoranu C M , Ernestus R , Löhr M , Hagemann C
Published: September 2023

BACKGROUND

The use of TTFields, which are alternating electric fields of low intensity (1-3 V/cm) and intermediate frequency (100-500 kHz), has shown its clinical efficacy in the treatment of newly diagnosed glioblastoma (GBM) patients at 200 kHz. Nevertheless, more knowledge is required for the prediction of individual tumors’ responsiveness to treatment. Recently, we developed patient-derived three-dimensional GBM tissue culture models to screen patient tumors for TTFields treatment susceptibility. Here, we extended these models to brain tumors beyond GBM, namely anaplastic ependymoma (AE) and oligodendroglioma. We cultured tumor-organoids as microtumors on murine organotypic hippocampal slice cultures (OHSCs) and subjected them to TTFields at 200 kHz.

MATERIAL AND METHODS

We prepared OHSCs by slicing the brains of mice 5-8 days postpartum to a thickness of 350 µm using a vibratome and culturing them for 14 days. We obtained organoids from freshly resected tumor tissue from three GBM, one AE, and one oligodendroglioma patient, each. The organoids were cultured for 14 days as well and then stained with carboxyfluorescein succinimidyl ester. Next, we placed the organoids onto the OHSCs and administered TTFields at 200 kHz and 1.5 V/cm for 72 h using the inovitro™ laboratory research system. We quantified microtumor growth by fluorescence imaging.

RESULTS

The three tumor entities, in particular organoids from GBM, AE and oligodendroglioma, grew as microtumors after being placed onto OHSCs. TTFields treatment at 200 kHz led to significantly decreased microtumor size of the three analysed GBM samples as well as the AE sample. However, the oligodendroglioma microtumor size was not significantly reduced.

CONCLUSION

Based on clinical experience, we expected that TTFields lead to a reduction in microtumor size. However, to our knowledge, we were the first to apply TTFields to patient-derived AE and oligodendroglioma samples. The lack of TTFields-effects on the latter might be due to different inter-patient sensitivity or suboptimal TTFields frequency. Nevertheless, our work is proof of principle that an organoid-based patient-derived 3D tissue culture model could be used to evaluate effects of TTFields on different brain tumor entities.
P10.07.A A CLINICALLY COMPATIBLEIN VITRODRUG-SCREENING PLATFORM IDENTIFIES THERAPEUTIC VULNERABILITIES IN PRIMARY CULTURES OF BRAIN METASTASES
Authors: Jeising S , Trübel J , Felsberg J , Picard D , Wolter M , Kaulich K , Häberle L , Esposito I , Steinmann J , Cornelius J , Beez T , Rapp M , Sabel M , Nickel A , Remke M , Reifenberger G , Qin N
Published: September 2023

BACKGROUND

Approximately 20% of cancer patients (including lung, melanoma, breast, renal, and colorectal cancer patients) develop brain metastases. Current systemic therapies often show limited efficacy for brain metastasis treatment and support palliative care only.

MATERIAL AND METHODS

In this preclinical study, short-term cultured primary cancer cells from brain metastasis patients were molecularly characterized using next-generation sequencing and functionally evaluated using high-throughput in vitro drug screening to identify pharmacological treatment sensitivities.

RESULTS

Next-generation sequencing identified matched genetic alterations between brain metastasis tissues and corresponding patient-derived cultured cancer cells. Mutant allele frequencies indicated that short-term cultures of cancer cells reflect the existence of distinct subpopulations of cancer cells within brain metastases. This indicates that our short-term cultured primary brain metastasis cells are suitable models for recapitulating heterogeneity in the sensitivity of tumor cells to anti-cancer drugs. Employing our in-house high-throughput in vitro drug screening platform, we additionally screened primary cultures from the brain metastasis patients for response to 267 anticancer compounds, and integrated the molecular and high-throughput drug screening data sets.

CONCLUSION

Our preclinical study thus provides proof-of-concept for combining molecular profiling with in vitro drug screening for improved prediction of therapeutic vulnerabilities in brain metastasis patients. This approach could advance the use of patient-derived cancer cells in clinical practice and might eventually facilitate decision-making for personalized drug treatment.
P10.08.B PI3K INHIBITION FOR SENSITIZING CANCER CELLS TO TUMOR TREATING FIELDS (TTFIELDS)
Authors: Klein-Goldberg A , Voloshin T , Zemer-Tov E , Paz R , Somri-Gannam L , Volodin A , Koren L , Wainer-Katsir K , Haber A , Dor-On E , Giladi M , Weinberg U , Palti Y
Published: September 2023

BACKGROUND

Tumor Treating Fields (TTFields) are electric fields that disrupt cellular processes critical for cancer cell viability and tumor progression, ultimately leading to cell death. TTFields therapy is approved for treatment of adult patients with glioblastoma (GBM) or unresectable pleural mesothelioma. Clinical trials are underway in other solid tumors, including ovarian cancer and non-small cell lung carcinoma (NSCLC). The objective of this study is to identify possible mechanisms involved in reduced sensitivity of cancer cell to TTFields, and explore strategies to circumvent them.

MATERIAL AND METHODS

GBM U-87 MG, ovarian cancer A2780, and NSCLC H1299 cells were treated with continuous long-term application of TTFields (1.7 V/cm RMS, 200 or 150 kHz, 6 or 13 days, specific conditions depending on cell line). Changes in signaling pathways were examined for cells following 3 days of treatment with Luminex multiplex assay, followed by Western blot validation for specific pathway markers. In vivo validation was performed in ovarian cancer (MOSE-L), hepatocellular carcinoma (N1-S1), and NSCLC (LL/2) tumor sections from animals treated with TTFields utilizing immunohistochemistry. Next, efficacy of TTFields concomitant with relevant inhibitors was evaluated in vitro and in mice inoculated orthotopically with ovarian cancer cells (MOSE-L). Tumor volume was measured at study end by luciferin signal detection using the In Vivo Imaging System (IVIS).

RESULTS

TTFields inflicted a cytotoxic effect on the cancer cells that increased over time, though with moderately reduced sensitivity following prolonged treatment application. PI3K/AKT signaling pathway was shown to be activated in treated cells, with the amplitude of AKT phosphorylation increasing over time. AKT phosphorylation was also demonstrated in tumor sections of animals treated with TTFields. Experiments performed with concomitant PI3K/AKT pathway inhibitors sensitized the cells to TTFields, enhancing cytotoxicity in vitro and treatment efficacy in vivo.

CONCLUSION

PI3K/AKT signaling pathway is involved in cancer cell reduced sensitivity to TTFields, and inhibition of this pathway sensitizes cancer cells to TTFields.