bluuebunny/crossref_metadata_2025_split huggingface dataset:
IMMU-22. TWIST1-MEDIATED ENDOTHELIAL PLASTICITY DRIVES GLIOBLASTOMA RESISTANCE TO CAR T IMMUNOTHERAPY
Authors: Yang Fan , Akhtar Md Naushad , Gong Yanqing , Fan Yi 
Published: November 2024

Abstract
Glioblastoma (GBM) is the most common and most aggressive malignant primary brain tumor in adults. Among the most lethal human malignancies, GBM is highly resistant to cytotoxic treatments and molecularly targeted therapies, and also generally refractory to T cell–based immunotherapies, largely due to their immunologically cold nature, i.e., characterized by a paucity of tumor T cell infiltrates that result from the immunosuppressive microenvironment. Here, we identify a distinct mechanism driven by spatiotemporal interaction of leukocytes with tumor stromal cells, namely, mesenchymal-like population of endothelial cells (ECs) form an immunosuppressive vascular niche that regulates macrophage polarization and induces GBM resistance to CAR T immunotherapy. Our single-cell transcriptome analyses of human and mouse GBM tumors identify a subpopulation of ECs acquire robust immunosuppressive phonotypes to drive alternative macrophage polarization. These ECs are spatially localized proximately to immunosuppressive macrophages and selectively express Twist1. Furthermore, we reveal a Twist1/SATB1-mediated sequential transcriptional activation mechanism, through which Twist1+ tumor ECs produce osteopontin to locally promote immunosuppressive macrophage phenotypes. Genetic or pharmacological ablation of Twist1 reverses macrophage-mediated immunosuppression and enhances T cell infiltration and activation, leading to reduced GBM growth and extended mouse survival. Importantly, pharmacological inhibition and lipid nanoparticle-mediated targeted inactivation of Twist1 overcome GBM resistance to Egfrviii CAR T cell immunotherapy. Thus, these findings uncover a spatially restricted mechanism controlling vasculature-mediated tumor immunity and suggest that targeting endothelial Twist1 may offer exciting opportunities for GBM immunotherapy.
IMMU-26. TARGETING CHK2-YBX1/3 INTERACTION TO OVERCOME IMMUNOSUPPRESSION IN GLIOMAS
Authors: Chen Li , Harish Mahalakshmi , Kalas Vasilios , Habashy Karl , Arrieta Victor A , Kim Kwang-Soo , Yeeravalli Ragini , Tiek Deanna M , Song Xiao , Mishra Snehasis , Wang Lu , Lee-Chang Catalina , Ahmed Atique U , Venkatraman Prasanna , Rocklin Gabriel J , Sonabend Adam M , Dmello Crismita 
Published: November 2024

Abstract
Whereas the contribution of tumor microenvironment to the profound immune suppression of glioblastoma (GBM) is clear, tumor-cell intrinsic mechanisms that regulate resistance to CD8 T cells are less studied. We performed an in vivo CRISPR screen to identify glioma intrinsic kinases that contribute to evasion of tumor cells from CD8 T cells. The screen revealed a DNA damage response gene-checkpoint kinase 2 (Chek2) to be the most important kinase contributing to escape from CD8 T-cell recognition. Genetic depletion or pharmacological inhibition of Chek2 with blood-brain-barrier permeable drugs that are in the clinical trials, in combination with PD-1/PD-L1 blockade, led to survival benefit in preclinical glioma models. Analysis of human GBMs demonstrated that Chek2 expression is inversely associated with antigen presentation and T-cell activation. However, the mechanism underlying the immunosuppressive function of Chek2 in gliomas is unknown. Here, we identified that glioma tumor cell intrinsic Chek2 interacts with Y-Box Binding Protein 1 and 3 (Ybx1&3) in ex vivo gliomas using immunoprecipitation followed by mass spectrometry. Independently, YBX3 was also identified as one of the most significantly phosphorylated protein upon Chek2 knockout using phosphoproteomics analysis. The YBX1&3 are DNA/RNA binding proteins implicated in transcriptional regulation of immune-modulatory genes. In silico docking using Alphafold and PIPER tool in Schrodinger revealed that the YBX1 cold-shock domain interacted near the ATP/ADP binding site in CHK2. This interface was also part of the CHK2-CHK2 dimer interface. Consistent with our model, disruption of CHK2 dimerization using prexasertib led to increased colocalization of CHK2-YBX1 in human GBM patient derived xenograft cells. Further, targeting of CHK2-YBX1 interaction with YBX1 inhibitor SU056 reversed the repression of IFNγ response genes in glioma cells. Together this study unveils a kinase independent (non-catalytic) function of CHK2, providing insight into the non-canonical immunosuppressive role of CHK2 in gliomas.
IMMU-56. THE TIGIT/CD155 AXIS PLAYS A CRITICAL ROLE IN EXTRACELLULAR VESICLE-MEDIATED PROGRAMMING OF THE GLIOBLASTOMA MICROENVIRONMENT
Authors: Asad Mohamad , Inocencio Julio , Mitrasinovic Stefan , Aoiki Minori , Parney Ian , Crisman Celina , Lasala Patrick , Eskandar Emad , Himes Benjamin 
Published: November 2024

Abstract
Glioblastoma (GBM), the most common and deadly primary brain tumor, exerts profound local and systemic immunosuppressive effects through a variety of mechanisms. Tumor-derived extracellular vesicles (EVs) are increasingly appreciated as critical mediators of these effects. In surveying the tumor-immune microenvironment in samples of ultrasonic aspirate collected during surgical resection of GBM (n=13), we identified several key immunomodulatory markers expressed across a range of myeloid cell populations. Particularly, we found TIGIT, classically understood as a T cell inhibitory protein, expressed across a range of myeloid cell populations in patient samples, including in myeloid-derived suppressor cells (MDSCs, 46.84±16.78% of total monocytic MDSCs). Using EVs collected from patient-derived cell lines, we were able to recapitulate these effects upon co-culture with monocytes derived from the peripheral blood of healthy donors (n=7). Furthermore, Induced MDSCs significantly inhibit T cells proliferation (70.97±8.454%, compared to control 19.4±5.71; p&lt;0.03), concomitant with a surge in Th2 immune responses via TIGIT/CD155 axis. This effect was reversed after TIGIT silencing, indicating a TIGIT-dependent immune suppression in the GBM microenvironment. Our study indicates EV-induced TIGIT upregulation in myeloid cells as a crucial immunosuppressive mechanism in glioblastoma, with potential therapeutic applications.
IMMU-61. THE LAST OF US: A FUNGI BASED DENDRITIC CELL VACCINE
Authors: Artiga Kevin , Valenzuela Alex , Hsu Mitchell , Wang Herui , Ye Juan , Zhuang Zhengping 
Published: November 2024

Abstract

BACKGROUND
Glioblastoma (GBM) is the most prevalent primary malignant brain tumor in adults. The current standard treatment for newly diagnosed GBM involves maximal surgical resection followed by radiotherapy and temozolomide. Despite these interventions, the median overall survival for GBM patients remains approximately 15 months, highlighting the critical need for innovative therapeutic approaches.

OBJECTIVE
Our laboratory has previously developed a subcutaneous autologous tumor vaccine incorporating irradiated (IR) tumor cells with phagocytosis-stimulating ligands (Mannan-BAM), toll-like receptor (TLR) agonists, and an immunostimulant anti-CD40 antibody (collectively termed MBT). This combination has shown efficacy in mouse models of colon carcinoma, breast cancer, melanoma, and, more recently, gliomas. Our study aimed to create a dendritic cell (DC) vaccine using this strategy.

METHODS
To evaluate whether MBT could induce the maturation of DCs in vitro, we harvested BMDCs from mice and co-cultured them in the presence of MBT-tagged irradiated tumor cells. We then analyzed the maturation markers using flow cytometry and assessed cytokine production via ELISA. To test the efficacy of this approach in vivo, we utilized two different murine glioma models (SB28 and GL261).

RESULTS
Using flow cytometry, we observed a significant upregulation of important co-stimulatory molecules. Additionally, ELISA analysis demonstrated that MBT-treated DCs significantly increased the secretion of Type 1 cytokines while limiting the secretion of the regulatory cytokine IL-10. MBT-primed DCs combined with immune checkpoint inhibitor PD-1 increased mouse survival in a glioma model compared to WT mice. However, mice eventually succumbed to cerebral edema. Histology demonstrated significant treatment effects.

CONCLUSION
Our results demonstrate that MBT effectively matures DCs ex-vivo. Further research is required to immunophenotype the response to vaccination in glioma models and explore ways to overcome resistance.
IMMU-69. THERAPEUTIC WINDOW ENABLING ERADICATION OF RESIDUAL GLIOMA STEM CELLS BY INTRACRANIAL NK CELL THERAPY FOLLOWING TEMOZOLOMIDE-INDUCED TUMOUR DEPOPULATION – A POSSIBLE ROLE OF CYTOTOXIC EXTRACELLULAR VESICLES
Authors: Meehan Brian , Adnani Lata , Zhu Xianbing , Tawil Nadim , Garnier Delphine , Nakano Ichiro , Huang Sidong , Rak Janusz 
Published: November 2024

Abstract
Glioblastoma (GBM) is an incurable brain cancer, where dismal outcomes result from disease recurrence driven by tumour-initiating glioma stem cells (GSCs). GSCs survive and expand in the brain after surgery, radiation and temozolomide (TMZ) amidst weak immune and natural killer (NK) cell surveillance. Efficient NK cell-mediated killing of GBM cells occurs at high effector to target ratios precluding effective eradication of large tumour remnants, as enforced by clinical trials with autologous NK cells in an adjuvant setting. Here we explore in a human GSC xenograft model whether tumor depopulation using high dose Temozolomide (TMZ) could create a window of curative opportunity for endogenous or exogenous NK cells. We observed that while subcutaneous (sc) xenografts of patient derived GSCs are infiltrated by endogenous functional (NCR1+) NK cells in SCID mice, the corresponding intracranial (ic) tumours remained NK cell depleted. Notably, while TMZ caused near complete regression of intracranial GSC xenografts this was followed by inevitable recurrence of drug-resistant lesions. To explore whether direct delivery of NK cells into depopulated intracranial tumours would change the lethal course of the disease, mice were injected with GSCs intracranially, and upon tumour formation were treated with a sequence of TMZ (systemically), at 2, 7, 14, and 21 days later with irradiated NK92MI cells. Remarkably, this combined therapy completely obliterated recurrent disease at 2 and 7 days but not beyond 14 days. To assess whether NK92MI cells could be replaced by their derived extracellular vesicles (NK-EVs), the latter were injected i.c. post TMZ in GSC xenograft bearing mice. A single injection of NK-EVs resulted in tumour eradication in some but not all mice. Thus, chemotherapy-dependent tumour depopulation may create a unique window of opportunity for curative NK-mediated immunotherapy in GBM.
INNV-12. CUTANEOUS TOXICITIES OF MITOGEN-ACTIVATED PROTEIN KINASE INHIBITORS IN CHILDREN AND YOUNG ADULTS WITH NEUROFIBROMATOSIS-1
Authors: Sadighi Zsila , Tripathy Sanjna , Peacock Brianna , Patel Anisha 
Published: November 2024

Abstract

BACKGROUND
Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder which commonly causes neoplasms leading to disfigurement or dysfunction. Mitogen-activated protein kinase inhibitors (MEKi) are generally well-tolerated treatments which target neural tumor progression in patients with NF1. Cutaneous adverse events (CAEs) are common and may hinder patients’ abilities to remain on treatment, particularly in children. We aim to characterize CAEs secondary to MEKi treatment in pediatric and young adult patients with NF1.

METHODS
We reviewed institutional medical records of patients under 30 years with a diagnosis of “NF1,” “NF2,” or “other neurofibromatoses” on MEKi therapy between January 1, 2019 and June 1, 2022. We recorded the time-to-onset, type, and distribution of CAEs, non-cutaneous adverse events (AEs), AE management, and tumor response.

RESULTS
The median age of 40 patients with NF1 was 14 years old. Tumor types included low-grade gliomas (51%) and plexiform neurofibromas (38%). MEKi used included selumetinib (69%), trametinib (25%), and mirdametinib (6%) (Table 1). A total of 74 CAEs occurred, with 28 cases of acneiform rash (38%) (Figure 1). Twenty-three out of the 28 cases of acneiform eruption were in post-pubertal patients (82.1%). Other common CAEs were paronychia, seborrheic dermatitis, eczema, xerosis, and oral mucositis. The most common treatments included oral antibiotics and topical corticosteroids. Most patients had clinical (stable or improved) tumor response (71%) while 29% had tumor progression while on a MEKi (Table 2). There was no significant association between CAE presence and tumor response (p=0.39).

CONCLUSIONS
MEK inhibitors have been demonstrated as a valuable treatment, but CAEs complicate the ability to stay on the treatment. Most patients in our cohort developed a CAE, demonstrating its prevalence in this population. Improvement in characterization of MEKi toxicities and their management is important to develop treatment guidelines for pediatric and young adult patients with NF1 on MEKi therapy.
INNV-32. LASER INTERSTITIAL THERMAL THERAPY FOLLOWED BY CONSOLIDATION STEREOTACTIC RADIOSURGERY (LITT-CSRS) IN PATIENTS WITH NEWLY DIAGNOSED BRAIN METASTASIS
Authors: Dharnipragada Rajiv , Shah Rena , Reynolds Margaret , Dusenbery Kathryn , Chen Clark 
Published: November 2024

Abstract

INTRODUCTION
The efficacy and safety of laser interstitial thermal therapy followed by consolidation radiosurgery (LITT-cSRS) was previously studied in brain metastasis that recurs locally after initial radiosurgery (BMRS). Here, we characterize the clinical outcome of LITT-cSRS in patients with newly diagnosed brain metastasis.

METHODS
Between 2017 and 2023, ten consecutive cancer patients with newly diagnosed brain mass of unclear etiology who underwent stereotactic needle biopsy (SNB) and LITT in the same setting followed by consolidation SRS (cSRS) with &gt; 6 months follow-up were identified retrospectively. Clinical and imaging outcomes were collected.

RESULTS
The histology of the BM were: breast cancer (n=3), melanoma (n=3), non-cell cell lung cancer (n=3), colon (n=1). There were no wound or procedural complications. All patients were discharged home, with a median one-day hospital stay (range: 1-2 days). All patients were off corticosteroid therapy by the one-month follow-up. cSRS were carried out 12-27 days (median of 19 days) after SNB+LITT. There were no subsequent emergency room presentation, 30-day or 90-day re-admission. The Karnofsky Performance Score (KPS) remains stable or improved at the 3 months-follow-up. With a median follow-up of 416 days (13.8 mo; range: 199-1,096 days), there was one local recurrence at 384 days (12.8 mo) post-LITT-cSRS. Of note, this is the only patient who underwent incomplete ablation with LITT and the location of the recurrence corresponded to the residual tumor that was not treated with LITT. With exception of this patient with local recurrence, all patients showed decreased FLAIR volume surrounding the LITT-cSRS treated BMRS by the six-month follow-up.

CONCLUSIONS
To our awareness, this case series represent the first to describe LITT-cSRS in the setting of newly diagnosed BM. The results presented here provide pilot data to support the safety and efficacy of LITT-cSRS and lay the foundation for future studies.
INNV-34. APPLICATION OF 200 KHZ TUMOR TREATING FIELDS (TTFIELDS) IN PATIENTS WITH INFRATENTORIAL HIGH-GRADE GLIOMA: CASE SERIES
Authors: Kamiya-Matsuoka Carlos , Patel Chirag , Battiste James 
Published: November 2024

Abstract

BACKGROUND
200 kHz Tumor Treating Fields (TTFields) therapy is FDA-approved for supratentorial newly-diagnosed and recurrent glioblastoma. However, reports of its application in patients with infratentorial high-grade glioma (HGG) are rare. Based on computational modeling, the therapeutic field strength (~1 V/cm peak-to-peak) is thought to be achievable for infratentorial HGG.

METHODS
Two patients with infratentorial HGG received off-label 200 kHz TTFields therapy with the Optune® device (Novocure, Ltd.). To reduce impaired range of motion of the neck, the electrode transducer arrays were “skeletonized” by cutting a portion of the adhesive material surrounding them. Application of the electrode arrays was performed with the neck in flexion, to further promote neck range of motion. Cloth tape was used for reinforcement as necessary. Electrode arrays were changed every 2-3 days. We report the results of patient survival and adverse events.

RESULTS
Patient 1: 22-year-old man with high-grade diffuse pontine glioma with recurrences and prior treatments (including radiation, temozolomide, lomustine, and dopamine receptor D2 [DRD2] antagonist), tolerated TTFields combined with systemic treatment (initially with a bi-functional DNA alkylating agent; subsequently with temozolomide and bevacizumab) for 5 months with stable disease for 4 months. He experienced grade 1 rash of the neck. Patient 2: 58-year-old woman with diffuse glioma of the brainstem (H3K27M-mutated) with multiple recurrences and prior treatments (including concurrent radiation and temozolomide, and DRD2 antagonist), tolerated TTFields combined with systemic treatment (lomustine and bevacizumab). The TTFields infratentorial layout was iteratively modified with respect to placement of the electrode transducer arrays, for improved tolerability. With the TTFields+systemic combination therapy, the patient was stable for 8 months with no local TTFields-related side effects.

CONCLUSIONS
We provide initial post-marketing evidence that off-label use of 200 kHz TTFields in infratentorial HGG is safe and feasible. Prospective studies are necessary to validate the efficacy of this approach.
PATH-03. SPATIAL-RESOLVED METABOLOMICS ANALYSIS IN HISTOLOGICAL AND MOLECULAR GLIOBLASTOMAS USING A MOF/MXENE-ASSISTED LDI-MSI PLATFORM
Authors: Guo Xiaopeng , Liang Weiqiang , Ma Chunxia , Zhao Yuanli , Wang Yu , Ma Wenbin 
Published: November 2024

Abstract
Glioblastoma (GBM) is a highly aggressive primary brain tumor encompassing both histological and molecular subtypes. Metabolites within the tumor microenvironment play critical roles in regulating tumor behavior and response to therapy. Understanding their spatial distribution provides valuable insights for diagnosis and treatment. We investigated metabolite patterns of histological GBMs (hist-GBMs) and molecular GBMs (mol-GBMs) by developing a novel MOF/MXene platform for enhanced surface-assisted laser desorption/ionization mass spectrometry. Utilizing this platform, we analyzed the metabolomes of three hist-GBMs and three mol-GBMs. Our platform exhibited exceptional sensitivity, repeatability, and stability in detecting metabolite molecules. Analysis of the metabolomes revealed distinct spatial distributions and concentrations of various metabolites, including carbohydrates, amino acids, organic acids, nucleotides, and their precursors. Notably, certain metabolites such as TG(15:0/20:3n6/20:5(5Z,8Z,11Z,14Z,17Z)), PG(20:3(6,8,11)-OH(5)/i-21:0), and SM(d20:1/20:3(6,8,11)-OH(5)) were significantly enriched in hist-GBMs compared to mol-GBMs, while others, including lithocholic acid glycine conjugate, PE(P-16:0/14:1(9Z)), and CE(11:1D5), exhibited higher peak intensity in mol-GBMs. Overall, our findings underscore the existence of unique metabolomic signatures distinguishing hist-GBMs from mol-GBMs. In conclusion, heterogeneous metabolite distributions among hist-GBMs and mol-GBMs were revealed by our novel MOF/MXene assisted LDI-MSI platform, and unique metabolic signatures were identified. Advanced metabolomics analysis holds promise for precise biomedical diagnostics and individualized therapeutic strategies in GBMs.
PATH-20. CLINICAL FINDINGS AND PROGNOSIS OF ADULT GLIOBLASTOMA HARBORING ABRAF V600E MUTATION
Authors: Yamaguchi Shigeru , Ishi Yukitomo , Oki Sogo , Motegi Hiroaki , Nishioka Kentaro , Mori Takashi , Okada Hiromi , Tanei Zen-ichi , Tanaka Shinya , Fujimura Miki 
Published: November 2024

Abstract

BACKGROUND AND AIM
Although the BRAF V600E mutation is commonly associated with pediatric low-grade gliomas, glioblastomas (GB) with this mutation (BRAF-GB) have also been reported. The recent emergence of RAF and MEK inhibitors for BRAF V600E-positive tumors highlights the potential for targeted therapy in a subset of GB patients. This study aimed to characterize the clinical features and prognosis of BRAF-mutant glioblastomas.

MATERIALS AND METHODS
A retrospective analysis was conducted on a cohort of patients diagnosed with GB (confirmed by 2021 WHO criteria) above 16 years of age. Targeted genetic analysis for mutations in BRAF V600E, TERT promoter, and CDKN2A/B was performed on the GB samples. Clinical features of BRAF-GB were analyzed, and patients were further categorized into three groups: BRAF-GB, typical GB, and molecular GB. Subsequent analysis compared the prognosis among these groups.

RESULTS
Our study identified 11 cases (5.1%) harboring the BRAF V600E mutation among 215 adult GB patients. Patients with BRAF-GB exhibited a significantly younger median age of onset (38-year-old) compared to the typical GB (N = 167, 64-year-old) and molecular GB (N = 37, 61-year-old) groups. Further analysis of the BRAF-GB cohort (n=11) revealed a high prevalence (82%) of homozygous CDKN2A/B deletions, and only one case (9%) harbored a TERT promoter mutation. Interestingly, three BRAF-GB patients presented with hemorrhagic onset. Four cases showed evidence of prior lesions, with one case diagnosed histologically as a low-grade glioma 14 years earlier. The BRAF-GB group exhibited significantly longer median progression-free survival (32.8 months) and overall survival (84.2 months) compared to both the typical GB group (9.6 months and 18.9 months, respectively) and the molecular GB group (14.1 months and 32.1 months, respectively).

CONCLUSIONS
Early-age onset, with hemorrhagic onset or presence of prior lesions are factors that could lead to recommendation of BRAF analysis for adult GB patients.