bluuebunny/crossref_metadata_2025_split huggingface dataset:
EXTH-13. COMBINED ANTI-ANGIOGENIC TREATMENT TO INCREASE INTRATUMORAL PERSISTENCE OF CAR T-CELLS IN LUNG CANCER BRAIN METASTASES
Authors: Blobner Jens , Eberle Constantin , Dengler Laura , Beck Alexander , Müller Katharina J , Teske Nico , Xu Tao , Karschnia Philipp , Ishikawa-Ankerhold Hellen , Thon Niklas , Tonn Joerg-Christian , Subklewe Marion , Kobold Sebastian , Harter Patrick N , Buchholz Veit R , von Baumgarten Louisa 
Published: November 2024

Abstract

BACKGROUND
Metastatic lung cancer, especially when it spreads to the brain, shows a devastating prognosis. Immunotherapeutic approaches including CAR T-cells show promise in hematologic malignancies. However, the presence of immunosuppressive factors within the tumor microenvironment and physical barriers like elevated interstitial pressure due to dysfunctional tumor vessels are one of the main obstacles especially in solid tumors. Evaluation of the potential synergy between anti-angiogenetic drugs and CAR T-cells in this context are an ongoing investigation.

METHODS
Here, we set up an immunocompetent syngeneic orthotopic cerebral metastasis model in mice by combining a chronic cranial window with repetitive intracerebral two-photon laser scanning microscopy (TPLSM). This model allows in vivo characterization of fluorescent tumor cells and CAR T-cells on a single cell level over time. Intraparenchymal injection of red fluorescent EpCAM-transduced Lewis Lung carcinoma cells (EpCAM/tdtLL/2 cells) followed by injection of EpCAM-directed or undirected CAR T-cells into the adjacent brain tissue was performed. Additionally, aVEGF-A combined with aVEGF-R2 and the respective isotype control were injected intraperitoneally.

RESULTS
Compared to undirected CAR T-cells, mice receiving EpCAM-directed CAR T-cells showed higher intratumoral CAR T-cell densities after intraparenchymal injection. This finding was accompanied with reduced tumor growth and eventually translates into a survival benefit. However, intratumoral CAR T-cell numbers diminish over time indicating insufficient persistence inside of the tumor microenvironment. Additional anti-VEGF-A/VEGF-R2 treatment results in reduced tumor growth after EpCAM/GFPCAR T-cell and GFPT-cell treatment, respectively. Interestingly, in vivo imaging reveals higher intratumoral CAR T-cell numbers after anti-angiogenic treatment compared to isotype controls pointing towards enhanced CAR T-cell persistence resulting in a survival benefit.

CONCLUSION
Collectively, our findings indicate that locally injected CAR T-cells may safely induce relevant anti-tumor effects in brain metastases from lung cancer. Additional anti-angiogenic treatment provides a mechanism to enhance intratumoral CAR T-cell persistence and reduce tumor growth.
EXTH-16. UNBIASED DISCOVERY OF SYNERGISTIC VULNERABILITIES AGAINST GLIOBLASTOMA: AN INNOVATIVEIN VIVO CRISPR PROFILING PLATFORM TO UNLEASH THE POWER OF TUMOR-TARGETED CYTOKINE THERAPY
Authors: Sakic Irma , Uijttewaal Esther C H , De Luca Roberto , Puca Emanuele , Weller Michael , Neri Dario , Elling Ulrich , Weiss Tobias 
Published: November 2024

Abstract

BACKGROUND
Glioblastoma poses a formidable challenge due to its intricate intra- and intertumoral heterogeneities and its associated immunosuppressive milieu. The standards of care have limited activity, and no major advances have been made in decades. One promising avenue is tumor-targeted cytokine-based therapies, particularly L19-TNF, which is undergoing clinical trials in Europe and the US for patients with newly diagnosed and recurrent glioblastoma. However, there is still an opportunity to find safer and more tolerable combination partners to improve the efficacy of L19-TNF immunotherapy. To address this challenge, we employed a cutting-edge in vivo CRISPR screening approach to identify synergistic vulnerabilities with a focus on druggable targets.

METHODS
We systematically investigated the dependencies of tumor growth and key signaling pathways under the pressure of L19-TNF immunotherapy in the CT-2A orthotopic murine glioma model. We used an innovative in vivo CRISPR screening approach that enables timed sgRNA activation to mitigate off-target effects and overcome orthotopic tumor cell implantation challenges, such as the bottleneck of cell engraftment.

RESULTS
We first conducted a genome-wide in vivo screen and identified 400 top-scoring candidate genes, which we subsequently tested again in a targeted in vivo screen to refine our drug selection process. Through this, we uncovered novel and previously unexplored druggable targets for glioblastoma. Out of these, we validated four promising target-specific drugs in preclinical glioblastoma models in downstream in vivo experiments. In addition, we investigated modes of action and resistance.

CONCLUSION
Our research marks a significant advancement in pursuing novel treatment strategies for glioblastoma. We have unveiled a range of synergistic combinations and paved the way for the rational design of combinatory treatment approaches to maximize the therapeutic efficacy of L19-TNF immunotherapy, laying the groundwork for future clinical translation.
EXTH-20. EXPLORING EUPHOL’S THERAPEUTIC EFFECT IN ADULT AND PEDIATRIC BRAZILIAN HIGH-GRADE GLIOMAS PRE-CLINICAL MODELS
Authors: Baroni Mirella , Tshikawa Leticia , Megid Raquel , Scremim Flavia , Gomes Izabela , Teixeira Gustavo , Lopes Luiz Fernando , Mançano Bruna , Polverini Allan , Lombardi Ismael , Junior Carlos , Teixeira Silvia , Reis Rui 
Published: November 2024

Abstract
High grade gliomas (HGG) are among the most aggressive brain tumors affecting both adults and children. Adult HGG (aHGG) account for almost 25% of all brain tumors in adults, with glioblastoma (GBM) being the predominant subtype. Pediatric HGG (pHGG), though less common, accounts for 3-15% of primary brain tumors in children and exhibits distinct genetic profiles compared to aHGG. Standard treatment for HGG in both adults and pediatric patients includes maximal surgical resection followed by temozolomide (TMZ)-based chemotherapy and radiation therapy. Our group previously reported that euphol, a natural compound derived from the sap of Euphorbiaceae family plants, exerts cytotoxicity effects on glioma cells. In this study, we investigated the therapeutic potential of euphol in primary cell cultures and xenograft models derived from six Brazilian HGG patients, including three adults and three pediatrics. In vitro, euphol exposure significantly reduced cell viability reduction, clonogenic capacity, and migration, while enhancing apoptosis in all six primary cultures. Additionally, euphol sensitized glioma cells to TMZ, resulting in a synergistic cytotoxic effect. In vivo, euphol reduced tumor growth in both GBM and pHGG models, and prolonged the survival of mice in the GBM orthotopic experiment. These findings highlight the promising therapeutic potential of euphol for treating high-grade gliomas in both adult and pediatric populations.
EXTH-22. TARGETING MITOCHONDRIAL PROTEASE IN DIFFUSE GLIOMAS
Authors: Kim Olga , Sergi Zach , Yu Guangyang , Li Qi , Lu Peng , Hsia Ru-Ching , Robey Robert , Chari Raj , Wang Herui , Tran Bao , Andresson Thorkell , Gottesman Michael , Liu Zhenggang , Graves Lee , Iwanowicz Edwin , Wu Jing 
Published: November 2024

Abstract

BACKGROUND
Targeting mitochondrial function has emerged as a promising therapeutic strategy in cancer treatment. TR107 is characterized as a specific activator of caseinolytic protease proteolytic subunit (ClpP) in the mitochondria, potentially affecting oncogenic pathways. Here, we investigated the effects of TR107 on adult malignant gliomas, IDH-wildtype and IDH-mutant

METHODS
We utilized patient-derived glioma cells to determine the efficacy of TR107 with cell viability, proliferation, cell cycle, and apoptosis assays. Immunofluorescent staining and electron microscopy (EM) were employed to uncover organelle morphological changes upon treatment. Mitochondrial function and ATP production were assessed in live cells utilizing Seahorse analysis. Global proteomics and RNA sequencing were performed to identify treatment-induced dysregulated pathways in glioma cells

RESULTS
Both IDH-wildtype and IDH-mutant glioma cell lines were highly sensitive to TR107, showing at least 100 times lower IC50 compared to the related compound ONC201. Genetic knock out of ClpP revealed that the growth inhibitory effects of TR107 are ClpP-dependent. Interestingly, IDH-mutant cell lines showed a more profound disintegration of mitochondrial morphology and dysregulation of mitochondrial function evidenced by an enhanced suppression of oxidative phosphorylation, mitochondrial complexes expression, mtDNA copy number, complex I activity, and ATP production, compared to IDH-wildtype cells. Six days of treatment with TR107 led to a complete inhibition of cell growth and up to 97% of cell death in IDH-mutant cells, while 50% of IDH-wildtype cells remained viable. Western blot, EM, and RNAsequencing analyses uncovered autophagy as a potential pro-survival mechanism in IDH-wildtype cells. Importantly, multiple metabolic and DNA repair-related pathways were affected by the treatment, suggested by global proteomics and RNA sequencing. Finally, TR107 was not affected by ABC transporters, supporting its potential use in brain tumor patients

CONCLUSION
TR107 demonstrated potent cytotoxic effects in patient-derived glioma cells by disrupting mitochondrial structural and functional integrity. TR107 efficacy in vivo is under investigation.
EXTH-24. THERAPEUTIC TARGETING OF MISLOCALIZED NUCLEAR ENVELOPE PROTEINS INMYC-DRIVEN GROUP 3 MEDULLOBLASTOMA
Authors: Suk Yujin , Ibañez-Vega Jorge , Chaudhry Iqra , Rossotti Martin , Subapanditha Minomi , Miletic Petar , Custers Stefan , Escudero Laura , Delaidelli Alberto , Nakashima Takuma , Xiao Yuxi , Moffat Jason , Suzuki Hiromichi , Sorensen Poul , Henry Kevin , Venugopal Chitra , Krenciute Giedre , Singh Sheila 
Published: November 2024

Abstract
Medulloblastoma (MB) is the most common, malignant pediatric brain tumour comprised of four distinct molecular subgroups (WNT, SHH, Group 3, and Group 4). A subset of Group 3 MB tumors harbors focal amplifications of the MYC oncogene (MYC-G3MB) and are particularly prone to tumour recurrence due to their highly proliferative nature linked to its embryonic stem cell-of-origin and programming. We discovered that LBR, an inner nuclear transmembrane protein, while present in all cells at the nuclear envelope (NE), is aberrantly presented to the cell surface in MYC-G3MBs. Transcriptomic profiling of publicly available datasets identified significant NE protein enrichment in MYC-G3MB compared to normal tissue and high expression during fetal development that dampens postnatally and in adult samples. Immunohistochemistry analysis of LBR on patient tumors was able to significantly prognosticate overall and progression free survival. Flow cytometry analysis identified LBR cell surface expression in MYC-G3MBs with low to no expression in human neural stem cells and other MB subgroups. High resolution microscopy of endogenously tagged LBR revealed cell surface presentation to be linked to ER-like vesicles that directly trafficked to the cell surface in MYC-G3MBs. Transcriptomic analysis of LBR cell surface positive and negative cells identified LBR to be linked to mitotic processes and mislocalization was significantly enriched following exposure to chemotherapy and radiation in vitro and in vivo. Therefore, we demonstrate that LBR is an ideal therapeutic target for patients facing treatment-refractory MB and have generated single domain antibodies (sdAb) to develop LBR-CAR T cells. Validation of LBR sdAbs demonstrate on-target binding and comparable affinity and avidity to commercial LBR antibodies. There is an undeniable paucity of targets for MB patients stemming from the lack of neoantigens and genomic aberrations in pediatric tumors. The preclinical development and validation of novel immunotherapeutic targets such as LBR provides alternative therapies for patients otherwise facing palliation.
EXTH-28. DEVELOPING A NOVEL INJECTABLE IMMUNOTHERAPEUTIC GEL FOR ENCAPSULATION OF NATURAL KILLER CELLS FOR POST-SURGICAL GLIOBLASTOMA TREATMENT
Authors: Huang Chiungyin , Chen Pinyuan , Wei Kuochen 
Published: November 2024

Abstract
Malignant brain tumors are one of the leading causes of death among all cancers. Approximately 40,000 people are diagnosed with malignant brain tumors every year. Among these patients, 15,000 cases are glioblastoma (GBM) with a very poor prognosis; even after aggressive surgical resection and adjuvant chemo/radiotherapy, the median survival is only 14.6 months. The major reason for poor prognosis is the blood-brain barrier, which prevents therapeutic agents from reaching the target area. Therefore, there are only a few choices of drugs available for brain tumor treatment. To date, temozolomide (TMZ) and the Gliadel wafer have been clinically used as standard chemotherapy agents after brain tumor resection. However, drug resistance to TMZ and the poor drug diffusion rate of the Gliadel wafer still result in ineffective suppression of residual cancer cells. To overcome the above-mentioned difficulties in clinical brain tumor treatment, in situ self-crosslinking multifunctional hydrogels was developed to carry natural killer cells (NK cells) and radiosensitizers as a novel brain tumor treatment system. Unlike traditional hydrogels catalyzed by pH value or temperature, this new system is stable and consistent as an immune cell carrier. We used fibrinogen, thrombin, and alginic acid as the backbone of the in situ self-crosslinking hydrogel, tested the properties of the synthesized hydrogel, and analyzed the gel-formation time and swelling rate. The release rate of NK cells was also examined. In a brain tumor animal model, the use of hydrogel-NK cells significantly inhibited tumor proliferation and prolonged animal survival time. In conclusion, this therapeutic hydrogel carrying NK cells can serve as a novel post-operation adjuvant therapeutic tool for malignant brain tumors.
EXTH-32. DUAL TARGETING OF CD155/TIGIT AND PD-L1/PD-1 IMMUNE CHECKPOINTS POTENTIATES NATURAL KILLER CELL-MEDIATED CYTOTOXICITY IN MEDULLOBLASTOMA
Authors: Monnikhof Matthijs , Schakelaar Michael , Meulenbroeks Chris , Quist Matthias , Perzolli Alicia , Selten Aimee , Koster Celeste , Maassen Daniëlle , Canelo Alba Montoro , Fredriks Maureen , Kaludjerovic Vela , Meeldijk Jan , Pijnappel Emma , Rebel Heggert , van Kempen Sven , Crnko Sandra , Frederico Aniello , Wesseling Pieter , Calkoen Friso , van der Lugt Jasper , ten Broeke Toine , Kool Marcel , Bovenschen Niels 
Published: November 2024

Abstract
Medulloblastoma (MB) is one of the most prevalent pediatric brain malignancies and makes up approximately 20% of all primary brain tumors in children. Current treatment options are not curative for about 30% of patients and leave survivors with an impaired quality of life. Immune checkpoint inhibition can offer a novel targeted therapy but largely remains understudied in MB. The aim of this study was to determine whether immune checkpoint inhibition can be used as a novel targeted therapy in MB. We used MB cell lines, MB patient-derived xenograft (PDX) organoid models, and primary patient-derived MB tissue to study immune checkpoints and their blockade to target MB. We identified the expression of immune checkpoint protein TIGIT on immune cells and its high-affinity ligand CD155 in medulloblastoma patient-derived tissues, cell lines, and PDX MB organoids. In addition, while MB shows weak, if any, PD-L1 protein expression, we found that MB cells can upregulate PD-L1 expression upon stimulation by natural killer (NK) cells via interferon-γ as a putative immune evasive strategy. Subsequent immunotherapeutic interventions with FDA-approved antibodies Tiragolumab (anti-TIGIT), Durvalumab (anti-PD-L1), and their combination potentiated primary NK cell activation and killing of MB cell lines and PDX-derived MB organoids. These data propose a translatable and novel immunotherapeutic strategy for patients diagnosed with MB.
EXTH-35. REPURPOSING OF CLINICALLY APPROVED GLUTAMATE ANTAGONISTS TO TREAT GLIOBLASTOMA
Authors: Uriach Dasca Julia , Marashli Samuel , Holland Eric C , Weller Michael , Wirsching Hans-Georg 
Published: November 2024

Abstract
The neurotransmitter glutamate plays a fundamental role in promoting epilepsy and tumor progression in glioblastoma. Glioblastoma cells secrete glutamate into the tumor microenvironment via the cystine-glutamate antiporter system Xc, leading to neuronal hyperexcitability, excitotoxicity, and tumor cell invasion. Additionally, glutamatergic neuroglioma synapses drive glioma progression in preclinical tumor models. To pharmacologically counteract effects of glutamate in glioblastoma, we employed a triple combination of anti-glutamatergic drugs: gabapentin, sulfasalazine, and memantine, which target glutamate synthesis, release, and post-synaptic signaling, respectively. In genetically engineered murine glioblastoma models, daily treatment with this triple combination prolonged median survival. This survival benefit was not observed with single or double drug combinations, nor with the standard antiepileptic drug levetiracetam, indicating the potential synergy and efficacy of this drug combination beyond merely treating epilepsy. Importantly, these preliminary results support the rationale for the ongoing phase Ib/II randomized clinical trial GLUGLIO, which explores the efficacy of combined gabapentin, sulfasalazine, and memantine in conjunction with standard chemoradiotherapy in patients with newly diagnosed glioblastoma (NCT05664464).
EXTH-50. THYROID HORMONE-INDUCED DIFFERENTIATION: A PROMISING THERAPEUTIC STRATEGY FOR MEDULLOBLASTOMA
Authors: Yang Yijun , Valdes-Rives Silvia , Ronsley Rebecca , Leary Sarah , Wechsler-Reya Robert , Yang Zeng-jie 
Published: November 2024

Abstract
Medulloblastoma (MB) is the most common malignant brain tumor in children, consisting of four major subgroups (WNT, SHH, Group 3, and Group 4) that differ in genetic/epigenetic profiles and prognoses. Despite current therapy, a significant proportion of patients still succumb to MB. Moreover, survivors often suffer severe side effects from aggressive treatments. Therefore, improved strategies to treat MB are urgently needed. MB tumor cells retain the capacity for differentiation and can undergo terminal differentiation, after which they lose their proliferative and tumorigenic capacity. This suggests that MB can potentially be treated by inducing tumor cell differentiation. However, the mechanisms underlying MB tumor cell differentiation remain unclear. Our recent studies reveal that thyroid hormone (TH) plays a critical role in promoting tumor cell differentiation in MB. Reduced TH levels free the TH receptor, TRα1, to bind to EZH2 and repress the expression of NeuroD1, a transcription factor that drives tumor cell differentiation. Increased TH levels reverse the EZH2-mediated repression of NeuroD1 by disrupting the binding between EZH2 and TRα1, thereby stimulating tumor cell differentiation and reducing MB growth. Importantly, triiodothyronine (T3, active form of TH) inhibits the growth of both SHH- and Group 3 tumors, suggesting that the tumor-inhibitory effect of T3 is not restricted by MB subgroups. Additionally, this effect is significantly enhanced by concurrent chemotherapy. These findings establish an unprecedented association between TH signaling and MB pathogenicity, providing solid evidence for TH as a promising therapeutic modality for MB treatment.
EXTH-51. ENHANCING GLIOBLASTOMA TREATMENT: ALLOGENEIC CAR-T CELLS OVERCOMES FUNCTIONAL DEFICITS OF PATIENT-DERIVED AUTOLOGOUS PRODUCTS
Authors: Vaseem Shaikh Muhammad , Salim Sabra K , Maich William T , Ananad Alisha , Wei Jeffrey , Subapanditha Minomi K , Suk Yujin , Singh Manoj , Tabunshchyk Zoya , Chen Katie , Vora Parvez , Venugopal Chitra , Moffat Jason , Singh Sheila K 
Published: November 2024

Abstract
Glioblastoma (GBM) is the most common primary brain malignancy in adults, with a dismal prognosis despite an intensive standard of care. Recently, chimeric antigen receptor T-cell (CAR-T) therapy has shown promising outcomes in treating liquid malignancies. However, clinical trials targeting various tumor antigens in GBM failed to show durable clinical benefit. Though this may stem from various tumor-intrinsic immune evasion strategies typical of GBM, there has been little work investigating whether the problem lies in the quality of the CAR-T products treatment itself. Currently, CAR-T cells for clinical studies are produced in an autologous setting, where T-cells are extracted from patients, engineered ex-vivo, and then re-infused. However, peripheral T-cells taken from GBM patients have shown qualitative and functional deficits, which may contribute to suboptimal treatment outcomes. Thus, we aimed to explore whether CAR-Ts generated from GBM patients had any functional deficits in comparison to healthy donors, utilizing our previously validated CD133 CAR-T. In this study, we show pre-treatment exhaustion, poor tumor control, and reduced survival advantage in autologous, patient-derived CD133-targeting CAR-T cell products using an orthotopic xenograft model of human GBM. To address the functional and logistical considerations of autologous therapy, we also sought to generate an “off-the-shelf” allogeneic CD133 CAR-T. Using CRISPR gene editing technology, we generated TCR-knockout CAR-T cells with comparable pre-clinical efficacy to our healthy donor derived autologous models. Ultimately, this work highlights the need to reevaluate autologous CAR-T therapy for GBM and consider allogeneic approaches as biologically-informed therapeutic alternatives.
EXTH-54. COMBINATORIAL DRUG SCREENING IDENTIFIES CARFILZOMIB AND ENZALUTAMIDE FOR TREATING AGGRESSIVE MENINGIOMAS
Authors: Jungwirth Gerhard , Braun Viktor , Nalcakan Derin , Pan Yimin , Warta Rolf , Abdollahi Amir , Unterberg Andreas , Krieg Sandro , Herold-Mende Christel 
Published: November 2024

Abstract
The goal of combinatorial therapy is to improve the effectiveness of treatment by targeting multiple aspects of cancer cells or overcoming resistance to single drugs. Therefore, we performed an automated combinatorial drug screening in meningioma cell lines and patient-derived tumor organoids (TOs). Three grade 3 meningioma cell lines (NCH93, IOMM-Lee, and KT21-MG1) were stably transduced with blue, green, and red fluorescence proteins. The cell lines were multiplexed into 384-well plates and treated in 5x5 dose-response (0-1000 nmol/l) matrices for 48h by the automated liquid handler Hamilton MicroLAB STAR®. The drug library consisted of 166 FDA-approved anticancer drugs. The viability of each cell line was demultiplexed by using fluorescence signals and CellTiterGlo. TOs were established from single cell suspensions of freshly resected meningioma tissue (n=20). The ZIP model was used to determine synergism. This drug screening effort generated 13,695 unique drug-drug combinations per cell line. Most synergistic combinations were observed in IOMM-Lee (1.14%), followed by KT21-MG1 (0.88%), and NCH93 (0.54%). The 110 most effective drug combinations were validated in wild-type meningioma cells. 75 drug combinations demonstrated a positive most synergistic area (MSA) score, indicating synergistic effects. Based on synergy scores and literature evidence, the 16 most promising combinations were selected for screening in TOs. The proteasome inhibitor carfilzomib in combination with the androgen receptor inhibitor enzalutamide exhibited the highest synergy in TOs. In 40% (n=8/20) of the cases, the combination showed strong synergism (MSA&gt;10) resulting in an overall average MSA of 7.36, followed by carfilzomib and neratinib, and romidepsin and gemcitabine with average MSAs of 5.49, and 4.32, respectively. Furthermore, carfilzomib and enzalutamide induced apoptosis in TOs assessed by Caspase-3/7. This comprehensive combinatorial drug screening identified the synergistic combination of the proteasome inhibitor carfilzomib and androgen receptor inhibitor enzalutamide that can be an effective treatment option for selected meningioma patients.