bluuebunny/crossref_metadata_2025 huggingface dataset:
KS05.7.A INTRATHECAL DELIVERY OF PEPTIDE-PULSED TYPE 1 CONVENTIONAL DENDRITIC CELL VACCINE IS HIGHLY EFFICACIOUS FOR THE TREATMENT OF BREAST CANCER-ASSOCIATED LEPTOMENINGEAL DISEASE
Authors: Law V , Snyder C , Chen Z , Kolinski P , Czerniecki B J , Forsyth P A
Published: October 2024

BACKGROUND

Approximately 5% of advanced stage breast cancer (BC) will develop leptomeningeal disease, a rare form of metastasis in the meninges, a membrane surrounding the brain and spinal cord. The prognosis for BC-LMD is dismal where current treatments are ineffective. For examples, intrathecal (IT) therapy such as trastuzumab, and proton cranial spinal radiotherapy have only showed modest success. Dendritic cells are a master regulator of the immune system and play a critical role in bridging the innate and adaptive immune response. Here, we used a novel preclinical model to administer MHC class II peptide-pulsed conventional Type 1 dendritic cells (cDC1s) intrathecally in mice harbouring either HER2+ or triple negative breast cancer (TBNC) LMD. The data from our preclinical studies led to an FDA-approved Phase 1 clinical trial of cDC1s in HER2+ and TNBC-LMD (NCT05809752; in progress).

MATERIAL AND METHODS

Our lab developed a “murine Ommaya” which mimics the clinically used Ommaya reservoir and allows for repeated intrathecal (IT) injections of novel drugs at 3 - 7μl volume directly into the CSF. A pipeline for screening immunogenic MHC class II peptides from tumor-associated oncodrivers was developed and using these targets we generated tumor-targeting cDC1 vaccines. The efficacy of this therapy was examined in murine BC-LMD models.

RESULTS

We found cDC1 vaccine was highly effective against HER2+ LMD and TNBC-LMD; LMD mice that received IT cDC1s had reduced tumour burden and prolonged survival. Complete responses to treatment ranged between 30 - 70% in HER2+ LMD and TNBC-LMD and were CD4+ T cell and B cell dependent. Notably, some cured mice were protected against LMD reinoculation. Subsequent single cell RNA-sequencing (scRNA-seq) analyses of pre- and post-treatment CSF revealed an adaptive change in the immune cellular landscape. We noted an elevation of Th1 cytokines such as IFN-γ in the CSF. This was recapitulated in the CSF samples of patients enrolled in an on-going Phase 1 trial, where early data showed IT cDC1 vaccine triggered a dramatic increase in the concentration of several Th1 proinflammatory cytokines.

CONCLUSION

Our preclinical data suggest IT cDC1 vaccine is effective against BC-LMD and prevents LMD recurrence. We are currently investigating the mechanism(s) by which IT cDC1-initiates the CD4 Th1 adaptive immune response against LMD. By employing an scRNA-seq approach, we hope to further determine the roles of different immune cells and their subtypes in the CSF to IT cDC1s in mice and in patients. A future approach includes testing IT cDC1 platform in LMD from other cancers (e.g. melanoma etc.).
JS02.5.A A PHASE 0/1B STUDY OF AZD1390 PLUS RADIOTHERAPY IN RECURRENT GLIOBLASTOMA PATIENTS
Authors: Sanai N , Umemura Y , Desai S , Margaryan T , Molloy J , Lo Cascio C , Elliott M , Harmon J , Hong A , Luna Melendez E , Wanebo J , Braun K , Kennedy W , Garcia M , Yoo W , Tovmasyan A , Tien A , Mehta S
Published: October 2024

BACKGROUND

ATM inhibition is hypothesized to potentiate the effects of radiation by preventing acute phase DNA damage repair, and a Phase 1 trial of this combination in patients with GBM is ongoing (NCT03423628). This Phase 0/1b study evaluated the pharmacokinetics (PK) and pharmacodynamics (PD) of AZD1390, a first-in-class ATM inhibitor, in combination with radiation in newly-diagnosed and recurrent GBM patients (NCT05182905).

METHODS

All patients received 3 days of AZD1390 prior to planned resection at 2-4, 4-6 or 23-25 hrs following the final dose (120/300mg for nGBM and 400mg for rGBM). Tumor tissue, cerebrospinal fluid (CSF), and plasma were collected. Total and unbound drug concentrations were measured using validated LC-MS/MS methods. ATM inhibition was assessed via ex vivo tissue radiation, quantifying pRAD50 levels compared to non-radiated control. A PK ‘trigger’ determined eligibility for Phase 1b and patients exceeding the PK threshold (2 nM unbound drug levels in Gd-non-enhancing tumor region) were eligible for therapeutic dosing of AZD1390 plus radiotherapy.

RESULTS

Thirty nGBM patients and twenty-nine rGBM patients were enrolled. Forty-eight out of the forty-nine evaluable patients exceeded the PK threshold and qualified for therapeutic dosing. The mean unbound concentrations of AZD1390 in Gd-nonenhancing tumors of nGBM patients were 13.2 pmol/g (4-6 hrs) and 4.4 pmol/g (23-25-hrs) at 120 mg dose and 17.9 pmol/g (4-6 hrs) and 4.5 pmol/g (23-25-hrs) at 300 mg dose. The mean unbound concentrations of AZD1390 were 75.6, 106.8, and 25.5 pmol/g in Gd-nonenhancing tumors of rGBM patients enrolled in 2-4, 4-6-, and 23-25-hrs cohorts, respectively. Following 5Gy ex vivo radiation of surgical specimens, pRAD50 expression was significantly suppressed in AZD1390-treated patients compared to untreated controls (median 0.2% (4-6 hrs 120mg), 1.9% (23-25 hrs 120mg), 0.3% (4-6 hrs 300mg), 1.1% (23-25 hrs 300mg), 1.2% (2-6 hrs 400mg) and 2.3% (23-25 hrs 400mg) vs 32.3% for control cohort, respectively. To date, six MGMT-unmethylated nGBM patients and 15 rGBM patients were enrolled in the Phase 1b component of the study, with median clinical follow-up of 7.0 months. Median progression-free and overall survival have not been reached in the nGBM population. Median OS was 15.4 months in the rGBM population.

CONCLUSION

AZD1390 is well-tolerated in both newly-diagnosed and recurrent GBM patients, achieving pharmacologically relevant concentrations in Gd-nonenhancing tumor tissue, and suppressing radiation-induced increase in pRAD50 levels. These data are the first to demonstrate AZD1390-mediated pharmacodynamic and pharmacokinetic response in GBM patients. Clinical efficacy data is maturing, but early results are encouraging.
JS02.7.A MAINTENANCE TEMOZOLOMIDE CHEMOTHERAPY FOR PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA: DOES TIME OF ADMINISTRATION MATTER?
Authors: Geurts M , Berchtold L , Koenig F , Naburs B , Reardon D A , Tonn J C , Stupp R , Gorlia T , Weller M , Preusser M ,   EORTC Brain Tumor Group
Published: October 2024

BACKGROUND

Chronotherapy, an innovative approach to improve survival or limit toxicity through timed administration of treatment, is of increasing in interest in cancer. In glioblastoma, preclinical models show that temozolomide activity depends on the time of the day it has been given. A retrospective study suggests improved outcomes for glioblastoma patients receiving temozolomide in the morning as compared to evening administration.

METHODS

We assessed toxicity and survival data in 755 patients enrolled in the CENTRIC EORTC 26071-22072 (n = 508) and CORE (n = 247) studies. Due to regulatory constraints, analyses had to be restricted to deceased patients only (n = 393 and n= 196 in CENTRIC and CORE respectively). We compared patients who were documented to have received temozolomide in the maintenance phase of the standard of care in the morning (<11.00AM) to those who received it in the evening (>6.00PM). Patients who received most of the maintenance temozolomide in the afternoon (between 11.AM and 6.00PM) were excluded.

RESULTS

A total of 260 (CENTRIC) and 154 (CORE) patients had at least one administration time available. In CENTRIC, n=102/260 (39%) received temozolomide in the morning and n=35/260 (13%) in the evening. In CORE, 50/154 (35%) patients received temozolomide in the morning and 34/154 (22%) in the evening. Patient- and disease characteristics were similar in both groups. There was no difference in general toxicity profiles between all groups (any AE, CENTRIC: morning 67/102 vs evening 24/35, p=0.8, CORE: morning 23/50 vs evening 14/34, p =0.7), but the morning group had a higher proportion of patients with bone marrow toxicity, compared to the evening group (CENTRIC: morning 34/102 vs evening 34/35, p=0.013, CORE: morning 12/50 vs evening 1/34, p<0.01). There was no difference in overall survival between the groups [CENTRIC median OS 20.1 months (95% CI: [14-33] months) morning vs 23.5 months (95% CI: [18-32] months) evening, p=0.5; CORE median OS, 10.9 months (95% CI: [10-13] months) morning vs 11.3 months (95% CI: [9.1-13] months) evening, p=0.8].

CONCLUSION

In this large prospective dataset, there was no indication that time of administration of maintenance temozolomide matters for survival of patients with newly diagnosed glioblastoma. However, our data suggest that bone marrow toxicity might occur less frequently when temozolomide is administered in the evening compared to the morning. This observation warrants further investigation. Given the limitation to data from deceased patients only, this analysis might be significantly biased and does not yet exclude that timing of temozolomide matters in patients most likely to derive benefit.
JS05.7.A TRAF7 WD40-DOMAIN MUTATIONS DRIVE MENINGIOMA TRANSDIFFERENTIATION AND INTRATUMOR HYPEROSTOSIS
Authors: Eaton C D , Goldschmidt E , Chen Z , Raleigh D R
Published: October 2024

BACKGROUND

Meningiomas are the only primary tumors that form lamellar, hyperostotic bone in the tumor microenvironment, but mechanisms that drive meningioma-induced hyperostosis (MIH) are incompletely understood. Clinical observations suggest TRAF7 short somatic variants (SSVs) are enriched in skull base meningiomas, and that SSVs targeting the TRAF7 WD40-domain may be associated with MIH. Here we use single-cell RNA sequencing and lineage tracing approaches to study regionally distinct samples from meningiomas with intratumor hyperostosis. Integrating bioinformatic data with mechanistic and functional studies across regionally distinct primary meningioma cell cultures, our results suggest that TRAF7 mutations are heterogeneous in individual meningiomas. Moreover, we find that TRAF7 WD40-domain mutations drive meningioma cell transdifferentiation into an osteoblast-like state that is associated with mineralization in vitro and MIH in vivo.

MATERIAL AND METHODS

Single-cell RNA sequencing and mitochondrial alteration enrichment from single-cell transcriptomes to establish relatedness (MAESTER) lineage tracing was used to define cell types, cell states, and evolutionary trajectories from 10 human samples. Regionally distinct primary meningioma cell cultures (n=6) were derived from hyperostotic or non-hyperostotic areas from 3 meningiomas with MIH and modified to stably express CRISPR interference machinery for mechanistic and functional studies. Targeted next-generation DNA sequencing, QPCR, immunofluorescence, cell proliferation, and mineralization assays with alizarin red stains were used to define how TRAF7 WD40-domain mutations influence meningioma cell fate.

RESULTS

Single-cell transcriptomics and lineage tracing identified a meningioma cell cluster that was enriched for bone-associated genes early in tumor development. DNA sequencing of regionally distinct meningioma samples and primary meningioma cell cultures revealed intratumor heterogeneity in TRAF7 WD40-domain mutations that correlated with MIH. Meningioma cell cultures were validated using DNA methylation profiling and SSTR2A expression. Only cell cultures from intratumor regions with MIH expressed RUNX2, SP7, or ALPL, and only cell cultures from intratumor regions with MIH underwent mineralization in vitro. Suppression of mutant TRAF7 using sgRNAs blocked in vitro mineralization, and media from meningioma cell cultures from intratumor regions with hyperostosis induced mineralization of TRAF7 wildtype meningioma cell cultures in vitro.

CONCLUSION

These data demonstrate that TRAF7 WD40-domain mutations drive meningioma transdifferentiation and intratumor hyperostosis, and shed light on fundamental mechanisms underlying lamellar bone formation.
JS08.6.A SYNTHETIC [18F]FET-PET GENERATION AND HOTSPOT PREDICTION VIA PREOPERATIVE MRI OF GLIOMA LACKING RADIOGRAPHIC HIGH-GRADE CHARACTERISTICS
Authors: Suero Molina E , Tabassum M , Azemi G , Özdemir Z , Valls Chavarria A , Roll W , Thomas C , Russo C , Liu S , Stummer W , Di Ieva A
Published: October 2024

BACKGROUND

Lack of availability of amino acid Positron Emission Tomography (PET) in many regions limits comprehensive therapeutic decision-making for patients with gliomas without typical high-grade imaging features. To address this gap, we evaluated a novel generative artificial intelligence (AI) approach for creating synthetic [18F]FET-PET and predicting high [18F]FET-uptake from multimodal magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Our approach involves training a deep learning (DL)-based model to segment tumors in preoperative MRI and extracting radiomic features using the pyradiomics package and classification with a Random Forest classifier. To generate [18F]FET-PET images, we employed a Generative Adversarial Network (GAN) framework and utilized a split-input fusion module for processing different MRI modalities through feature extraction, concatenation, and self-attention. We employed four principal metrics for quality assessment: Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), Root Mean Square Error (RMSE), and Visual Information Fidelity (VIF).

RESULTS

We included MRI and PET images from 215 studies for the hotspot classification task and 211 studies for the synthetic PET generation task. The top-performing radiomic features achieved 80% accuracy for hotspot prediction. Of all the [18F]FET-PET scans generated synthetically, 90% were classified as clinically useful by senior physicians. PSNR analysis indicated high signal fidelity with a peak at 40 dB, while SSIM values showed substantial structural congruence. RMSE analysis demonstrated lower values below 5.6, indicating a robust congruence of the synthetic PET. Complementing these findings, VIF scores mostly ranged between 0.6 to 0.7, reflecting a high level of visual information fidelity and affirming that the synthetic PET images retain the critical informational content required for clinical assessment and diagnosis.

CONCLUSION

For the first time, we demonstrate that predicting high [18F]FET-uptake and generating synthetic PET images out of multimodal MRI in LGG and HGG is feasible. Furthermore, we can predict higher [18F]FET-uptake with high accuracy. Advanced MRI modalities and other generative AI models will be used to improve the algorithm further in future studies.
OS01.4.A MODELING EGFR REGULATION IN GLIOBLASTOMA REVEALS ASSOCIATIONS WITH ITS LIGANDS
Authors: Ghisai S A , Barin N , van Hijfte L , de Heer I , van den Bent M J , Hoogstrate Y , French P J
Published: October 2024

BACKGROUND

Approximately half of the IDH-wildtype glioblastomas (GBM) exhibit EGFR amplification, with highly varying copy number levels. Additionally, extracellular mutations in EGFR occur, leading to either ligand hypersensitivity (R108K/A289V/G598V) or ligand-independence (EGFRvIII). Contrary to EGFR-mutated lung adenocarcinoma (LUAD), clinical trials with EGFR inhibitors have not yet improved survival outcome for GBM. Our research aimed to elucidate the molecular mechanisms of EGFR activation and regulation in GBM and make comparisons with LUAD.

MATERIAL AND METHODS

We devised Random Forest models to identify EGFR co-regulated genes and pathways in GBM by leveraging RNA-sequencing data from TCGA-GBM (n=142) and the Intellance-2/EORTC_1410 (n=211) trial. Additionally, we compared EGFR signaling patterns between GBM and LUAD, where LUAD RNA sequencing data (n=508) were collected from TCGA. Sources of expression signals were determined by screening both in-house and public single cell and single nucleus RNA sequencing (sc/snRNA-seq) data from GBM (n=28) and LUAD (n=45). Multiple primary and established GBM and LUAD cell lines were used for in vitro functional studies.

RESULTS

Among the significant EGFR predictor genes (TCGA-GBM: n=169, Intellance-II: n=166), we found two ligands (BTC and EREG). Expression of these ligands was inversely correlated with the EGFR amplification level and presence of ligand-sensitizing mutations. Samples with ligand-sensitive mutations showed a downregulation of genes involved in the RB and TP53 pathways (CDK4, MDM2, CDKN2A). Our analyses showed a tumor-type specific expression profile in GBM and LUAD when comparing tumors carrying activating mutations. Sc/snRNA-seq analysis showed that EGFR ligands were primarily expressed by non-malignant cells, but differed in their source of expression between tumor types: GBM (BTC: neurons, EREG: myeloid) and LUAD (BTC: cilia, EREG: myeloid). The level of expression of nearly all EGFR ligands was significantly higher in LUAD than in GBM, which may be related to the presence of ligand-sensitizing mutations in the latter. Functional analysis on primary cultured glioma- and established cell lines showed no overt differences between GBM and LUAD in EGFR internalization and ligand-induced transcriptional regulation.

CONCLUSION

EGFR ligands BTC and EREG showed a significant and negative association with EGFR expression in GBM. These findings emphasize the potential role of ligands in regulating EGFR, where EGFR activation seems to be triaged by the highly varying level of EGFR amplification, sensitivity of the receptor towards the different ligands and ligand expression levels. These findings provide a better understanding of EGFR regulation in GBM and might eventually be used for patient stratification.
OS05.5.A DOSE ESCALATED SPINE RADIOSURGERY FOR RADIORESISTANT SPINAL METASTASES UTILIZING SIMULTANEOUS INTEGRATED BOOST
Authors: Ghia A J , Bernard V , Iskander G , Rooney M , De B , Briere T M , Tatsui C E , Bishop A , Perni S , Tom M , Wang C , Beckham T , Yeboa D N , McAleer M , Li J , Amini B , Rhines L D
Published: October 2024

BACKGROUND

Spine stereotactic body radiosurgery (SSRS) delivers ablative doses of radiation with sub-millimeter precision leading to high rates of local control with minimal toxicity. Treatment dose, fractionation and technique vary from institution to institution. We present our experience delivering single fraction SSRS using simultaneous integrated boost (SIB) for radioresistant spinal metastases.

MATERIAL AND METHODS

This is a single institution retrospective review analyzing patients treated from 2006-2021 with single fraction SSRS delivering 24 Gy to the gross disease (GTV) and 16 Gy to the clinical target volume (CTV) at risk of harboring microscopic disease per International consensus guidelines. We assessed clinical endpoints in relation to patterns of failure, including local control (LC) and overall survival (OS), using univariate and multivariate analyses.

RESULTS

From 2006-2021, 395 sites from 285 patients were treated with SSRS. With a median follow-up of 18 months, the actuarial 1- and 2-year local control (LC) was 93% and 89%, respectively. The most common pattern of failure was epidural (67%). Indeed, multivariate analysis revealed the presence of epidural disease as a significant predictor of local failure (HR 3.42, 95% CI 1.71-6.85 p=0.001). Of the 39 sites with local failure, only 2 sites were within the CTV volume outside of the GTV volume. The median overall survival was 26 months and no radiation myelopathy was noted. Grade 3 vertebral fracture was noted in only 5% of treated sites (20 fractures out of 395 sites).

CONCLUSION

This is the largest experience on SSRS using SIB for radioresistant spinal metastases. SSRS with SIB delivered to 24 Gy in 1 fraction is associated with a high local control rate with low toxicity. Failures outside the GTV and within the CTV were very rare and clinically significant fracture risk was 5% suggesting that SIB is a reasonable approach for radioresistant spinal metastases treated with SSRS.
OS05.7.A RADIATION-INDUCED CONTRAST ENHANCEMENT AFTER PROTON THERAPY IN PATIENTS WITH GLIOMAS IN THE PRO-CNS STUDY
Authors: Werlenius K , Agrup M , Flejmer A , Gojon H , Jakobsson F , Bergström P , Dahl L , Parcaoglu F , Strandéus M , Kinhult S , Morhed E , Gustavsson M , Modin K , Heggebø L , Witt Nyström P , Rylander H , Store Jakola A , Brandal P , Blomstrand M
Published: October 2024

BACKGROUND

Although proton radiotherapy has been used in a large scale for quite some time, published data from trials confirming the safety of proton therapy are still scarce. Yet, there are indications of radiation induced contrast enhancement (RICE) being more common after proton radiotherapy than photon radiotherapy.

MATERIAL AND METHODS

Between August 2015 and August 2020, adult patients receiving proton therapy for primary CNS tumours at the Skandion clinic in Sweden were invited to PRO-CNS, a prospective multicentre observational cohort study. We identified 120 patients with glioma WHO grade 1-3 in the PRO-CNS study. The patients received a total dose of 50.4 Gy (RBE), 54 Gy (RBE) or 59.4-60 Gy (RBE) in 1.8-2.0 Gy (RBE) fractions. Discrimination between RICE and true tumour progression was assessed by experienced neuroradiologists and neurooncologists. So far, only the 45 patients from Gothenburg have been analysed.

RESULTS

Preliminary data from the Gothenburg cohort show RICE in 70% of patients receiving a dose of 59.4 Gy (RBE). This is a considerably higher incidence of RICE than previously reported in patients treated with photons to the same dose. For comparison, 18% of patients receiving 50.4 Gy (RBE) and 21% receiving 54 Gy (RBE) developed RICE. Furthermore, RICE seemed to be slightly more common among patients treated for oligodendroglioma than astrocytoma, but the numbers are too small to draw conclusions. Analysis of the whole cohort of 120 patients is ongoing with the intention to be presented in 2024.

CONCLUSION

Our preliminary results raise concern on toxicity after proton treatment to 59.4 Gy (RBE) in glioma patients. These are preliminary results and further evaluation is needed.
OS06.5.A ACCURATE AND COMPREHENSIVE EVALUATION OF MGMT PROMOTER METHYLATION BY NANOPORE SEQUENCING
Authors: Halldorsson S , Nagymihaly R M , Leske H , Brandal P , Panagopoulos I , Lund-Iversen M , Patel A , Sahm F , Vik-Mo E O
Published: October 2024

BACKGROUND

The methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) promoter region is essential in evaluating the prognosis and predicting the drug response in patients with glioblastoma (GBM). In this study, we evaluated the utility of using nanopore long-read sequencing as a method for assessing methylation levels throughout the MGMT CpG-island, compared its performance to established techniques, and demonstrated its clinical applicability.

MATERIALS AND METHODS

We analysed 165 samples from CNS tumours, focusing on the MGMT CpG-island using nanopore sequencing. Oxford Nanopore Technologies (ONT) MinION and PromethION flow cells were employed for single sample or barcoded assays, guided by a CRISPR/Cas9 protocol, adaptive sampling or as part of a whole genome sequencing assay. Methylation data obtained through nanopore sequencing were compared to results obtained via pyrosequencing and methylation bead arrays. Hierarchical clustering was applied to nanopore sequencing data for patient stratification.

RESULTS

Nanopore sequencing displayed a strong correlation (R² = 0.91) with pyrosequencing results for the four CpGs of MGMT analysed by both methods. The MGMT-STP27 algorithm’s classification was effectively reproduced using nanopore data. Unsupervised hierarchical clustering revealed distinct patterns in methylated and unmethylated samples, providing comparable survival prediction capabilities. Nanopore sequencing yielded high-confidence results in a rapid timeframe, typically within hours of sequencing, and extended the analysis to all 98 CpGs of the MGMT CpG-island.

CONCLUSIONS

This study presents nanopore sequencing as a valid and efficient method for determining MGMT promotor methylation status. It offers a comprehensive view of the MGMT promoter methylation landscape, which enables the identification of potentially clinically relevant subgroups of patients. Further exploration of the clinical implications of patient stratification using nanopore sequencing of MGMT is warranted.
OS06.6.A LOCAL DELIVERY OF HRBMP4 AS AN ANTICANCER THERAPY IN PATIENTS WITH RECURRENT GLIOBLASTOMA: A FIRST-IN-HUMAN PHASE 1 DOSE ESCALATION TRIAL
Authors: Bos E M , Binda E , Verploegh I S , Wembacher E , Hoefnagel D , Balvers R K , Korporaal A L , Conidi A , Warnert E A H , Trivieri N , Visioli A , Zaccarini P , Caiola L , van Wijck R , van der Spek P , Huylebroeck D , Leenstra S , Lamfers M L M , Ram Z , Westphal M , Noske D , Legnani F , DiMeco F , Vescovi A L , Dirven C M F
Published: October 2024

BACKGROUND

This Phase 1 study evaluates the intra- and peritumoral administration by convection enhanced delivery (CED) of human recombinant Bone Morphogenetic Protein 4 (hrBMP4) - an inhibitory regulator of cancer stem cells (CSCs) - in recurrent glioblastoma.

MATERIAL AND METHODS

In a 3 + 3 dose escalation design, over four to six days, fifteen recurrent glioblastoma patients received, by CED, one of five doses of hrBMP4 ranging from 0·5 to 18 mg. Patients were followed by periodic physical, neurological, blood testing, magnetic resonance imaging (MRI) and quality of life evaluations. The primary objective of this first-in-human study was to determine the safety, dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) of hrBMP4. Secondary objectives were to assess potential efficacy and systemic exposure to hrBMP4 upon intracerebral infusion. Dynamics of BMP signaling were assessed by RNAseq, and differentiation induction was investigated by immunofluorescence.

RESULTS

Intra- and peritumoral infusion of hrBMP4 was safe and well-tolerated. We observed no serious adverse events related to this drug. Neither MTD nor DLT were reached. Three patients had increased hrBMP4 serum levels at the end of infusion, which normalized within 4 weeks, without sign of toxicity. One patient showed partial response and two patients a complete (local) tumor response, which was maintained until the most recent follow-up, 57 and 30 months post-hrBMP4. Tumor growth was inhibited in areas permeated by hrBMP4.

CONCLUSION

Local delivery of hrBMP4 in and around recurring glioblastoma is safe and well-tolerated. Three patients responded to the treatment. A complete response and long-term survival occurred in two of them. This warrants further clinical studies on this novel treatment targeting glioblastoma CSCs.
OS07.3.A DYNAMIC METABOLIC SHIFTS RESHAPE GLIOBLASTOMA: IMPACTS ON SPATIAL STRUCTURE AND IMMUNE RESPONSE
Authors: Conrad N , Benotmane J , Villa G , Schnell O , Heiland D , Kueckelhaus J
Published: October 2024

BACKGROUND

The structured layers of the human neocortex stand in sharp contrast to the disordered arrangement found in malignant CNS tumors. Glioblastoma (GBM), with its diverse characteristics, presents formidable hurdles in both research and treatment, as successful approaches demand a uniform biological understanding. In this study, we capitalize on recent advances in spatial biology, employing integrated spatially resolved transcriptomics and metabolomics to identify the factors driving the unique architectural changes observed in GBM.

MATERIAL AND METHODS

We performed spatial metabolomics (MALDI) and transcriptomics (Visium n=43 and MERFISH n=25) of glioblastoma patients. Computational analysis was performed with the SPATA2 R package.

RESULTS

We found that most spatially recurrent pattern in glioblastoma emerge in a gradient-like organization,particularly influenced by proximity to areas of necrosis and hypoxia. Samples without hypoxic regions demonstrated less spatial organization. Metabolomic and transcriptomic profiling revealed enhanced responses to hypoxia coupled with reduced cell proliferation and elevated expression indicative of the S-phase in cell division in regions near necrosis. The vicinity to hypoxic areas appeared to be associated with increased chromosomal alterations as well as extracellular matrix remodeling and epithelial-to-mesenchymal transition, implying that the invasive capabilities of GBM cells originate from these hypoxic niches. By further integrating spatially resolved TCR-sequencing, we identified that hypoxic gradients drive defined T cell response with higher likelihood of T cell dysfunction within a distance of 235 μm (sd: 132 μm) to hypoxia. This suggests that the presence of necrosis, hypoxia, and hypoxia associated metabolites could serve as potential predictive markers for T-cell behavior and exhaustion in glioblastoma.

CONCLUSION

Our investigation provides a comprehensive examination of the impact of two common environments in glioblastoma: necrosis and hypoxia. We demonstrate that the intricate structure of glioblastoma is not merely shaped by genetic chance and random events. Rather, it is substantially molded by spatial proximity to critical elements such as necrosis and hypoxia. This understanding contributes to an advancing framework aimed at unraveling the complex biology of glioblastoma.
OS07.4.A INTERLEUKIN-6 INCREASES STRUCTURAL AND ELECTROPHYSIOLOGICAL CONNECTIVITY IN GLIOMA
Authors: Picart T , Krishna S , Daniel A , Dada A , Oten S , Hyer J , Hervey-Jumper S
Published: October 2024

BACKGROUND

In the setting of glioblastoma (GBM), the pleiotropic cytokine interleukin-6 (IL-6) upregulates PD-L1 expression through STAT3-dependant mechanisms. This leads to local immunosuppression, sustains tumor progression and may explain the limited efficacy of immune checkpoint inhibition. Consistently, IL6 knock-out in orthotopic murine glioma models diminishes tumor growth and increases survival. IL-6 increases synaptogenesis during development and contributes to neuronal network remodeling following focal spinal cord or brain injury. Yet, the contribution of IL-6 to glioma-induced circuit remodeling from a structural and electrophysiological perspective is poorly understood and is investigated herein.

MATERIAL AND METHODS

The expression of IL-6 was compared in magnetoencephalography (MEG)-based intratumoral regions of High- (HFC) and Low-Functional Connectivity (LFC) from GBM patients using bulk and single-cell RNA sequencing and immunofluorescence staining in a panel of gliomas with biological replicates (n=44 samples). In mouse postnatal cortical neurons and primary patient-derived glioblastoma cell co-cultures, the effects of exogenously applied recombinant human IL-6 and the humanized anti-IL-6 receptor (IL6R) antibody TOCILIZUMAB (TCZ) on Ki67, GAP43, and synaptic marker expression, tumor connectivity and neuronal activity were monitored. Co-culture analysis were validated with human and mouse cortical organotypic glioblastoma slices.

RESULTS

IL-6 was overexpressed in HFC compared to LFC regions, independently of tumor grade. In neuron and GBM co-cultures, the number of tumor microtubes per cell was significantly increased by the addition of recombinant IL-6 and decreased by TCZ treatment. The addition of recombinant IL-6 increased the expression of the tumor microtube marker, GAP43 and modified the expression profile of synaptic markers. Electrophysiological recordings, from multielectrode array (MEA), showed a significant increase in the neuronal activity metrics, such as weighted mean firing rate, network burst frequency and duration, and also the neuronal synchrony index following the addition of recombinant IL-6. Additionally, the proliferation index of GBM cells was significantly increased by exogenous recombinant IL-6 and decreased by TCZ treatment.

CONCLUSION

These findings suggest that IL-6-signaling increases structural and electrophysiological connectivity in gliomas and may contribute to neuronal network hyper-excitability and synchrony. Additional experiments are required to more precisely understand the IL-6-driven molecular mechanisms promoting glioma-induce circuit remodeling. These data will help to design new therapeutic options likely to improve the oncological and functional outcomes of patients treated for diffuse gliomas.
OS07.5.A MULTI-MODAL EXAMINATION OF SPATIAL HETEROGENEITY IN THE ASTROCYTOMA MICROENVIRONMENT
Authors: Lu T , Freytag L , Moffet J , Kriel J , Whittle J , Freytag S , Best S A
Published: October 2024

BACKGROUND

Astrocytoma is a diffuse and heterogeneous glioma that infiltrates the brain. Despite post-operative therapy including radiation and chemotherapy, 52% of patients’ tumours recur within five-years of surgery. These tumours are characterised by mutations in the IDH1 or IDH2 gene that confer metabolic alterations, most notably the production of the onco-metabolite 2-hydroxyglutarate. To reveal the metabolic alterations and their upstream regulation across the heterogeneous tumour microenvironment, we applied spatial metabolomics and spatial transcriptomics to sequential sections from resected tumour samples of patients with low grade astrocytoma.

METHODS

Spatial assessment of heterogeneity was performed on serial sections using spatial metabolomics (atmospheric pressure MALDI-TOF) and spatial transcriptomics (10X Genomics Xenium). This necessitated extensive optimisation of image registration across modalities and sequential sections to create three dimensional models to deeply interrogate heterogeneity within tumours.

RESULTS

Combining spatial transcriptomics and spatial metabolomics across 8 matched sequential slices of the same patient tumour, enabled the identification of metabolic niches associated with distinct cell type composition and transcriptional regulation. Strikingly, normal domains that were present at the leading edge of tumours could be identified both metabolically and transcriptomically.

CONCLUSIONS

Understanding the heterogeneity of astrocytomas on a spatial level reveals unique domains and organisation of tumour and immune cell types. Matching these transcriptomic and cell state information with metabolic insights leads to pathway insights that will be essential to the identification of druggable targets. Our pipeline combining spatial transcriptomics and metabolomics with tissue histology reveals these biologically important domains.
OS07.9.A NETWORK ANALYSIS IDENTIFIES CSF2RA’S GENETIC COMMUNITY AS A REGULATOR OF PROGRESSION IN THE INVASIVE REGION OF HIGH GRADE GLIOMA
Authors: Stevens V , Flick M , Sereduk C P , Plaisier C L , Barajas R F , Hu L S , Kannan K , Tran N L
Published: October 2024

BACKGROUND

High-grade glioma (HGG) is the most common and aggressive form of primary brain cancer with poor prognosis. Standard of care surgery employs Magnetic Resonance Imaging to identify the contrast enhancing (CE) core for resection, typically leaving behind a non-enhancing (NE) invasive rim of tumor which invariably contributes to recurrence. Recent multi-omics analyses identified predominant neuronal and immune signatures within NE tumor, which could provide key insights for combatting recurrence. We present the novel application of graph network analyses to integrate multi-omic data from a unique dataset of multi-regional spatially-localized CE and NE biopsy samples from a large cohort of patients with HGG.

MATERIAL AND METHODS

159 IDH-wildtype tumor biopsy samples from NE and CE regions of 74 glioma patients were profiled by RNA sequencing. Differentially expressed genes (DEGs) across NE and CE samples (n = 1159) were determined using the EdgeR package, and represented as nodes within a Neo4j graph network. Samples were hierarchically clustered for each gene (method = median), and edges were generated between gene nodes sharing ≥ 1 sample. Modularity optimization was used to identify communities of densely connected nodes. Genes occurring exclusively within NE communities were localized by cell type using external single-cell RNA sequencing datasets and identified as source node candidates for NE network random walks. These were performed with CSF2RA nodes as source (walk length = 5; 10,000 walks/source node). Random walks traversing samples with significantly elevated CSF2RA expression (one-tailed test) were kept for analysis. Genes occurring at high frequency (one-tailed test) within random walks were ranked by correlation with CSF2RA expression in NE samples and analyzed by gene set enrichment analysis (GSEA) for biological processes using clusterProfiler.

RESULTS

CSF2RA, an immune signaling receptor gene, was upregulated (logFC = 0.789) in NE samples and uniquely occurred within NE communities. We show its differential expression within the immune-enriched Glycolytic/Plurimetabolic (GPM) glioma subtype and confirm its enrichment in myeloid populations across single cell HGG datasets. NE network random walks identified 46 DEGs associated with CSF2RA. GSEA revealed upregulation of proliferative and metabolic signatures and downregulation of signaling pathways within CSF2RA’s network.

CONCLUSION

CSF2RA’s genetic network in NE tumor represents a potential mechanism for immunologic facilitation of glioma progression within this region. Given the expression of CSF2 ligand by glioma cells, which plays a crucial role in recruiting myeloid cells during peripheral cancer progression, modulating the expression of key genes in the CSF2RA network may be a promising approach for perturbing the crosstalk signals between immune and tumor cells in the NE region.
OS08.7.A STIMULATED RAMAN HISTOLOGY FOR INTRAOPERATIVE DIAGNOSIS IN PEDIATRIC BRAIN TUMORS
Authors: Kiesel B , Körner L , Makolli J , Vogel C , Haberler c , Dorfer C , Widhalm G
Published: October 2024

OBJECTIVE

Intraoperative frozen sections for neuropathological assessment is an essential tool in pediatric neurosurgical tumor resection. However, preparation as well as analysis of the tumor tissue can take as long as 45 minutes. Recently, stimulated Raman histology was introduced as a novel technique to provide a rapid high-resolution digital image of an unprocessed tissue sample directly in the operating room. The aim of this study was to evaluate the use of stimulated raman histology during pediatric brain tumor surgery.

METHODS

All patients aged 18 years or younger who underwent a biopsy or resection of a suspected tumor lesion were included in the current study. Intraoperatively, tissue samples of the suspected tumor lesion were collected. One sample was prepared and sent to the neuropathology department and a conventional frozen section was performed. Additionally, a sample was used for stimulated raman histology analysis directly in the operating room. In a further step, a tool was applied to provide a histopathological diagnoses using artificial intelligence. Conventional intraoperative frozen section and images obtained using stimulated raman histology were compared and analyzed.

RESULTS

In total 55 patients were included. The median age of our patient cohort was 9 years and included 25 female and 30 male patients. In all cases stimulated raman histology showed comparable images as the conventional frozen sections. The most common histopathological diagnosis was pilocytic astrocytoma followed by diffuse glioma, Medulloblastoma and Ependymoma. In 25 cases diagnosis using artificial intelligence was available and applied. In 50% the provided diagnosis was confirmed by histopathological assessment. In the other half of the cases AI diagnosis was not correct.

CONCLUSION

Stimulated raman histology represents a useful rapid intraoperative tool to obtain images comparable to conventional frozen sections and thus provide important information for the neurosurgeon to optimize surgical management. The AI tool may in future represent a helpful tool to provide a rapid intraoperative diagnosis.
OS09.5.A UNEXPECTED FUNCTIONAL ROLE OF GLYCOCALYX ENCAPSULATION DURING GBM METABOLIC ADAPTATION OPENS AVENUES FOR NEW TREATMENT CONCEPTS
Authors: Bång-Rudenstam A , Cerezo-Magaña M , Gonçalves de Oliveira K , Governa V , Talbot H , Kjellen L , Tykesson E , Malmström A , van Kuppevelt T , Forsberg-Nilsson K , Bengzon J , Belting M
Published: October 2024

BACKGROUND

The inherent adaptive capacity of GBM to metabolic stress represents a key clinical challenge, and the underlying mechanisms remain ill-defined. Our lab focuses on the emerging role of lipid metabolism in cancer cell stress adaptation. We have previously found increased scavenging of lipid particles, including extracellular vesicles (EVs) and lipoproteins, during acute stress, further resulting in a lipid droplet (LD) storage phenotype. Here, we propose a new mechanistic link between chondrotin sulfate proteoglycan (CSPG) remodelling, extracellular lipid scavenging, and LD formation that together serve to fine tune intracellular lipid metabolism to escape ferroptosis.

MATERIAL AND METHODS

We have comprehensively profiled GBM tissues and cells during different acidic stress adaptation conditions, including freshly resected GBM specimens, primary GBM cultures, and established GBM cell-lines. Methods/analyses include: Multiomics (RNA, proteome, glycome), laser capture microdissection for spatial profiling, snRNA-seq, immunophenotyping by FACS and imaging, and in vitro treatment studies (in 2D and 3D) with live imaging of cytotoxicity and ferroptosis. Mouse GBM models were employed for in vivo treatment studies.

RESULTS

We provide first evidence of a functional role of cell-surface CSPGs during GBM adaptation to metabolic acidosis. Substantial CSPG induction coincides with LD formation in a process dependent on extracellular lipids and acidification. Specifically, CSPG encapsulation of stressed GBM cells acts as a shield against excessive lipid particle scavenging while LDs consitute an intracellular sink for lipid storage. Based on these findings, we introduce combined targeting of CSPGs and LDs as a strategy to challenge the stressed tumor niche. Concomitant disruption of CSPG and LD formation unleashes a metabolic vulnerability in acidic cells driven by uncontrolled lipid uptake and peroxidation, mitochondrial disintegration, and ferroptotic death.

CONCLUSION

In conclusion, this study identifies a potentially targetable adaptative mechanism in the treatment resistant, acidic niche of GBM. We propose that cancer cell escape from acidic stress involves the induction of CSPGs - providing a shield against the lipid rich tumor microenvironment - and LDs - forming an intracellular lipid sink. Combined targeting of CSPG and LD formation to induce ferroptosis may offer new therapeutic opportunities in GBM and other solid tumors.
OS10.5.A MINIMALLY INVASIVE BRAIN METASTASES ARE CHARACTERIZED BY AN ACTIVE, ANTI-CANCER IMMUNE INFILTRATE
Authors: Maritan S M , Karimi E , Dankner M , Hernandez-Corchado A , Yu M W , Rezanejad M , Liu B , Fiset B , Wei Y , Nehme A , Park M , Riazalhosseini Y , Najafabadi H , Petrecca K , Guiot M C , Quail D F , Walsh L A , Siegel P M
Published: October 2024

BACKGROUND

Cancer metastasis to the brain is a common complication of advanced disease with limited therapeutic options. Although immune checkpoint inhibition has shown some efficacy in treating brain metastases (BrM), patient response is variable, in part due to the unique composition of the brain tumor immune microenvironment (TIME). Our group has shown that BrM can grow in two distinct patterns, either as minimally invasive (MI) masses with well-defined borders, or as tumors with highly invasive (HI) growth into surrounding brain tissue. Here, we investigate how the TIME differs between MI and HI BrM.

MATERIAL AND METHODS

We use Nanostring Digital Spatial Profiling coupled with the Cancer Transcriptome Atlas panel on BrM from 20 patients to quantify 1,825 cancer-specific RNA targets in cancer cells at the tumor-brain interface. Additionally, we perform imaging mass cytometry (IMC) on 119 BrM from 46 patients, encompassing over 350,000 cells. Samples represent BrM from various primary sites (lung, breast, melanoma, other), and include patient-matched samples from the brain-tumor interface and the centre of the metastatic lesion. Additional multiplexed immunohistofluorescence staining was performed on a subset of 18 patients with lung cancer BrM.

RESULTS

Gene set enrichment analyses revealed elevated interferon gamma signalling in MI versus HI BrM, which was confirmed by immunohistochemical staining for pSTAT1, consistent with an “immune hot” TIME in MI BrM. IMC revealed that MI BrM had significantly higher frequencies of lymphocytes, including B cells, CD4+, CD8+, CD4- CD8-, and regulatory T cells compared to HI BrM. Pairwise cellular association analyses revealed increased interactions between lymphoid cell populations in MI versus HI BrM, suggestive of specific regions enriched in B and T cells in MI BrM, rather than a generally diffuse infiltrate. Indeed, cellular neighbourhood analyses revealed a lymphoid-rich cellular neighbourhood that was more abundant in MI versus HI BrM and localized to the tumor-brain interface. Multiplexed immunohistofluorescence staining revealed that T cells were more likely to be cytotoxically active and exhausted in MI versus HI BrM.

CONCLUSION

These data suggest that HI BrM invade into an immunosuppressed microenvironment while MI BrM are characterized by an active anti-tumor immune infiltrate, predominantly localized to the tumor-brain interface. Together, this work suggests potential immune regulation of BrM invasion. Work is ongoing to identify factors present in the HI BrM environment that enforce an immunosuppressive environment. This research has been supported by grants from the Terry Fox Foundation and the Quebec Breast Cancer Foundation (Grant #: 251427-251690) and the Canadian Institutes of Health Research (CIHR PJT-175066) to P.M.S.
OS12.5.A IMPROVING HEALTH EDUCATION FOR BRAIN TUMOR PATIENTS AND RELATIVES THROUGH ANIMATED AND VISUAL INFORMATION
Authors: Baas-Thijssen M C , Nogarede-Bloemendaal C O , Docter-Kerkhof C S
Published: October 2024

BACKGROUND

Brain tumor patients interact with a wide range of healthcare professionals. It is important that they receive simple and unequivocal information about what awaits them. This contributes to shared decision making, an individual treatment plan and informed consent. Providing information becomes challenging when people are communicatively vulnerable, i.e. when they are ill or experience intense emotions. A high number of brain tumor patients are communicatively vulnerable because they have cognitive deficits or language impairments. Information processing may become slower because of the tumor and/or treatment. In 2023 the neuro-oncology task group of OncoWest, a network in the west of the Netherlands, prioritized the improvement of health care education for patients with a primary brain tumor.

MATERIALS AND METHODS

Visual and spoken information combined was considered best for brain tumor patients, including those with low literacy. A graphics agency was approached to create animations and a project team was assembled. The team consisted of two nurses, a clinical linguist and a communication advisor. They devised the content and texts for three main topics: care process, treatments and consequences. Texts were written in B1, a language level understood by the majority of Dutch citizens. Other factors were also taken into account, such as length of sentences, use of active tense and total duration of the videos. The texts were then reviewed by specialists in the field of neuro-oncology, and patients. A voice actor finally did the voiceover. Clinical linguists gave intermediate feedback on the animation videos. The videos still seemed too complex and fast for individuals with aphasia. Therefore, an additional tool was developed for people with aphasia as to provide extra written information, illustrated by stills from the videos. A clinical linguist simplified the text and bolded important words.

RESULTS

Three animation videos were developed of about three minutes each, all freely accessible, with explanation and information about 1) the care process from initial complaints to diagnosis, 2) possible treatments surgery, radiotherapy, chemotherapy and best supportive care, 3) symptoms and consequences of the disease. Furthermore an interactive pdf was made available for patients with aphasia and could be printed.

CONCLUSION

We described the development of clear, easily accessible visual information for brain tumor patients. The information is now available for patients, including everyone around the patient, which will hopefully increase their understanding and health care process. We hope to promote and evaluate the use of these materials in the near future.