bluuebunny/crossref_metadata_2025_split huggingface dataset:
EXTH-40. IMMUNOPHENOTYPING OF RWTC-MBTA AUTOLOGOUS CANCER VACCINE IN PRECLINICAL GLIOBLASTOMA MODELS
Authors: Wang Herui , Ye Juan , Medina Rogelio , Zhang Yaping , Chakraborty Samik , Uher Ondrej , Vanova Katerina Hadrava , Zenka Jan , Pacak Karel , Zhuang Zhengping 
Published: November 2024

Abstract
Despite advances in immunotherapy, glioblastoma multiforme (GBM) remains challenging to treat due to its low inherent immunogenicity and a suppressive tumor microenvironment. Converting “cold” GBMs to “hot” tumors is crucial for effective immune activation and improved patient outcomes. We comprehensively characterized the rWTC-MBTA autologous cancer vaccine, consisting of Mannan-BAM-anchored irradiated whole tumor cells, Toll-like receptor ligands (LTA, Poly(I:C), R-848), and an anti-CD40 agonistic antibody, in preclinical GL261 and SB28 GBM models. A substantial number of vaccinated mice exhibited complete regression of GBM tumors in a T-cell-dependent manner, with no significant toxicity. Long-term tumor-specific immune memory was confirmed upon tumor rechallenge. In the vaccine-draining lymph nodes of the SB28 model, rWTC-MBTA vaccination triggered a major rise in cDC1 12 hours post-treatment, followed by an increase in cDC2, moDC, and pDC on Days 5 and 13. Enhanced cytotoxicity of CD4+ and CD8+ T cells in vaccinated mice was verified in co-culture with tumor cells. Comprehensive immunophenotyping in the GL261 and SB28 GBM microenvironments confirmed decreased regulatory T cells and increased CD4+ and CD8+ T cell infiltration in vaccinated mice. T-cell exhaustion analyses revealed an increase in the Tim3+CD8+ T cells. No significant differences were observed in the quantification of M-MDSC and PMN-MDSC between control and vaccinated mice, but PD-L1 expression significantly increased in M2 macrophages in vaccinated mice. Our findings demonstrate that rWTC-MBTA induces potent and long-term adaptive immune responses against GBM, warranting further investigation of combinations with other immunotherapies for enhanced efficacy.
EXTH-41. COMBINATION TREATMENT WITH RAF/MEK AND FAK INHIBITION ENHANCES TUMOR GROWTH INHIBITION IN MENINGIOMA
Authors: Ijad Nazanin , Waller Katie L , Yamazawa Erika , Nayyar Naema , Summers Elizabeth J , Migliarese Christian , Galanis Evanthia , Carlson Brett L , Sarkaria Jann N , Wakimoto Hiroaki , Vaubel Rachael A , Brastianos Priscilla K 
Published: November 2024

Abstract

BACKGROUND
Patients with meningiomas who have progressed after multimodal treatments face a significant shortage of viable therapeutic options. Recent advancements in the molecular understanding of meningiomas have identified the FAK and RAF/MEK signaling pathways as potential promising targets for progressive meningiomas.

METHODS
In vitro, we tested two human meningioma cell lines, IOMM-Lee (NF2 wild-type and CDKN2A loss) and CH157-MN (NF2 mutant). The cells were plated in Matrigel-coated wells, treated with defactinib (FAK inhibitor), VS-6766 (RAF/MEK inhibitor, avutometinib) and the combination over a 7-day period and assessed for cell viability using the CellTiter-Glo 3D assay. In vivo, we tested the efficacy of the FAK inhibitor VS-4718 (possessing favorable pharmacokinetic properties in mice) and RAF/MEK inhibitor VS-6766, both given daily via oral gavage, in athymic nude mice bearing IOMM-Lee or CH157-MN tumors.

RESULTS
In the matrigel assay, VS-6766 suppressed IOMM-Lee and CH157-MN cells in a dose dependent manner. The drug combination was mostly additive in IOMM-Lee cells. However, CH157-MN cells showed a strong synergistic response across all drug concentrations tested. In the IOMM-Lee flank tumor model, VS-4718 alone had no effect, while VS-6766 alone or in combination significantly reduced tumor growth and extended median survival from 25 days to 47 days (p &lt; 0.05). In the CH157 flank tumor model, VS-4718 monotherapy did not affect tumor growth or survival, but VS-6766 monotherapy slowed tumor growth and increased median survival from 10 days to 31 days (p &lt; 0.001). Combining both drugs further reduced tumor growth and extended median survival to 42 days (p &lt; 0.001).

CONCLUSION
Treatment with FAK and RAF/MEK inhibitors showed synergistic or combination effects in the NF2 mutant CH157-MN model in vitro and in vivo. RAF/MEK inhibitor monotherapy was effective for the IOMM-Lee model (NF2 wild-type), without clear benefit of combining with the FAK inhibitor. Investigations in intracranial tumor models are underway.
EXTH-43. ANTI-GLIOMA ACTIVITY OF BIMODAL CGAS-AGONISTIC AND STAT3-INHIBITORY SPHERICAL NUCLEIC ACIDS
Authors: Mahajan Akanksha , Dussold Corey , Kim Seunghyun , Jarvis Rachel , Tommasini Serena , Forsyth Connor , Hurley Lisa , Mirkin Chad , Stegh Alexander 
Published: November 2024

Abstract
Activation of the cGAS-STING (cyclic GMP-AMP synthase-stimulator of Interferon Genes) pathway enhances T cell activation and infiltration into tumors, reversing the immunosuppressive phenotype of myeloid cells. Targeting the STING receptor with synthetic cyclic dinucleotide (CDN) ligands offers a promising immunotherapeutic strategy for lymphocyte-depleted, myeloid cell-enriched tumors like Glioblastoma (GBM). However, this approach is constrained by the structural instability of CDNs and the presence of immune-evasive, STING-inhibitory mechanisms in the tumor microenvironment (TME), particularly those driven by the master transcriptional regulator STAT3 (Signal Transducer and Activator of Transcription 3). To activate cGAS anti-tumor responses and simultaneously inhibit STAT3-driven immunosuppression in the GBM TME, we developed Spherical Nucleic Acids (SNAs) consisting of a nanoparticle core densely functionalized with radially oriented stem-loop dsDNA oligonucleotides containing a guanine repeat element flanked by palindromic STAT3 decoy sequences. In vitro studies demonstrated that these SNAs effectively activate cGAS and inhibit STAT3 in reporter cell lines, exhibit high-affinity binding to both the cGAS enzyme and STAT3 proteins, and downregulate IL-6-induced STAT3 transcriptional targets. Furthermore, intratumoral injection of these bimodal SNA architectures induced type I interferon (IFN) and proinflammatory cytokines, activated T cells and B cells, and natural killer cells; and reprogrammed immunosuppressive tumor-associated macrophages (TAMs). Importantly, bimodal SNAs showed profound sex-based differential pharmacological action with therapeutic benefits seen in females but not in male mice in aggressive immune checkpoint-resistant murine glioma models. In the absence of cGAS transcriptional changes, western blot and flow cytometry analysis revealed that cGAS protein levels were approximately twice as high in female BMDMs (bone marrow-derived macrophages) and TAMs than males. In summary, our study establishes bimodal SNAs as a first-in-class, single-entity nucleic acid therapeutic capable of targeting multiple pathways for the immunological reprogramming of the GBM TME.
EXTH-44. ENHANCING THERAPEUTIC APPROACHES IN HIGH-GRADE GLIOMAS: SYNERGISTIC EFFECTS OF LSD1 AND KINASE INHIBITION
Authors: Stitzlein Lea M , Hernandez Faith A , Nam Deokhwa , Patel Kareena , Impelman Katie , Poche Alaina L , Su Xiaoping , Gumin Joy , Sareddy Gangadhara R , Lang Frederick F , Chandra Joya 
Published: November 2024

Abstract

BACKGROUND
Glioblastoma (GBM) and Diffuse Intrinsic Pontine Glioma (DIPG) are devastating high-grade gliomas (HGGs) with poor prognoses. Lysine-specific demethylase 1 (LSD1) is a promising therapeutic target and a key regulator in tumor initiation and recurrence. Crosstalk between LSD1 and other signaling pathways, such as the MAPK pathway, frequently hyperactivated in HGG, offers an opportunity to enhance the efficacy of LSD1 inhibitors. This study investigates the combined inhibition of LSD1 and kinase signaling to improve therapeutic outcomes in HGG.

METHODS
Transcriptional changes following LSD1 knockdown in human GBM cells were analyzed using RNA-seq and GSEA. RPPA and western blotting assessed the impact of LSD1 inhibition on kinase signaling. Pharmacological LSD1 inhibition was tested using NCD38 or bomedemstat in HGG models and normal human astrocytes (NHA). The effects of combining LSD1 inhibitors with kinase inhibitors (osimertinib, afatinib, and ulixertinib) on cell viability were evaluated. Combination treatment was also assessed in orthotopic xenograft models of GBM.

RESULTS
GSEA revealed LSD1 expression was enriched for gene sets involved in kinase signaling processes. Increased phosphorylated ERK1/2 levels were observed following NCD38 treatment in MDA-GSC17, as shown by RPPA and western blot analyses. The LSD1 inhibitor, NCD38, increased phospho-ERK1/2 levels (72% increase from baseline), while co-treatment with osimertinib mitigated this effect. Combined LSD1 and kinase inhibition (EGFR and ERK inhibition) showed synergistic effects in vitro in GBM and DIPG models but not in the NHA.

DISCUSSION
Our results demonstrate that kinase activity can be modulated by inhibiting LSD1, potentially leading to a resistant subpopulation. This study underscores the potential of combining LSD1 and kinase inhibition to enhance therapeutic efficacy in HGG, including GBM and DIPG. Future research will focus on elucidating the mechanisms by which LSD1 regulates kinase signaling, aiming to optimize combination therapies.
EXTH-47. ENHANCING GD2.CART THERAPY FOR DIFFUSE MIDLINE GLIOMA WITH LSD1 AND HDAC INHIBITORS
Authors: Murdaugh Rebecca , Shekar Meghan , Eberl Brittany , Tremblay Jack , Richard Rosemary , Harmanci Akdes Serin , Omer Bilal , Anastas Jamie 
Published: November 2024

Abstract
Chimeric antigen receptor T cells against the glycolipid GD2 (GD2.CARTs) are showing promise in diffuse midline glioma (DMG) but are not yet curative. Since low target antigen expression is one potential mechanism by which tumor cells can escape CART therapy, we profiled GD2 expression levels on 9 different H3K27M-mutant DMG cell lines using flow cytometry. This analysis shows that only 5 of the 9 cell lines exhibit high GD2 expression while the remaining 4 lines have low GD2-expressing cells. When treating these cell lines with GD2.CARTs in co-culture assays and xenograft mice, we find that low GD2 expression on DMG cells correlates with tumor cell escape from GD2.CARTs and therapeutic resistance in vivo. Our lab previously found that simultaneous inhibition of histone deacetylases (HDACs) and lysine-demethylase 1 (LSD1) in DMG cells causes synergistic increases in gene expression and tumor cell death. Previous studies in neuroblastoma also demonstrate that HDAC inhibitor (HDACi) treatment can increase GD2 on tumor cells and improve targeting by GD2.CARTs. We therefore decided to assess whether treating GD2-low DMG cell lines with combinations of LSD1 inhibitors (LSD1i) and HDACi improves DMG response to GD2.CARTs. Immunofluorescence and flow cytometric analyses show that GD2 expression is increased on LSD1i+HDACi-treated GD2-low DMG cells and that there is enhanced tumor cell targeting by GD2.CARTs in subsequent co-culture assays. Treating mice transplanted with GD2-low DMG cells with LSD1i+HDACi followed by intravenous GD2.CART infusion also led to reduced tumor growth. These results suggest that LSD1i+HDACi pre-treatment may provide a way to improve DMG patient responses to GD2.CART therapy by increasing target antigen expression.
EXTH-53. THE PHARMACOLOGICAL ATLAS OF MENINGIOMAS
Authors: Jungwirth Gerhard , Pan Yimin , Nalcakan Derin , Warta Rolf , Abdollahi Amir , Unterberg Andreas , Krieg Sandro , Herold-Mende Christel 
Published: November 2024

Abstract
No systemic treatment options exist for recurrent or refractory meningioma patients. This study aimed to create a pharmacological atlas of all FDA-approved oncology drugs in a large cohort of patient-derived meningioma organoids (TOs). TOs were generated from single cell suspensions from freshly resected meningiomas and were treated with semi-logarithmic concentrations spanning from 10 nM to 30 µM by the automated liquid handler Hamilton MicroLAB STAR®. The drug library AODX from the National Cancer Institute consisted of 179 FDA-approved anticancer drugs. The viability was measured with the RealTimeGlo (Promega). Half-maximal inhibitory concentrations (IC50) were calculated by GraphPad Prism software. We created a pharmacological atlas of meningiomas by generating 8,413 dose-response curves of 179 current FDA-approved oncology drugs in patient-derived tumor organoids from 47 meningioma patients. The cohort consisted of 35 grade 1, 11 grade 2, and 1 grade 3 meningiomas, including 10 recurrent tumors. In total, 21% (n=39/179) of the drugs exhibited sensitivity (median IC50 &lt; 30 µM), with significant enrichment for topoisomerase, RNA/protein synthesis, proteasome, and HDAC inhibitors. The top five drugs with the lowest IC50 values were romidepsin, dactinomycin, carfilzomib, plicamycin, and omacetaxine with median values of 10, 31, 145, 303, and 400 nM. Hierarchical clustering of IC50 data revealed at least two distinct drug response clusters defined by sensitivity to tyrosine kinase inhibitors. When considering the Cmax/IC50 ratio as a potential predictive marker of treatment response (&gt;1), the HDAC inhibitors belinostat (74.5), romidepsin (69.7), the proteasome inhibitor carfilzomib (34.6), and the anthracyclines epirubicin (2.6), and doxorubicin (1.8), and the PI3K inhibitor idelalisib (1.6) are the most promising drug candidates for further in vivo evaluation. We provide the first comprehensive insight into the pharmacological landscape of meningiomas. This data might serve as the foundation for future clinical studies on the systemic treatment of aggressive meningiomas.
EXTH-58. BLOCKING IMMUNE CHECKPOINT— LAIR1: DISRUPTING THE LAIR1—FXIII-A—COLLAGEN IMMUNOSUPPRESSIVE CIRCUIT FOR ENHANCED ANTITUMOR THERAPEUTICS
Authors: Tao Haipeng , Chen Dongjiang , Yang Changlin , Nguyen Duy T , Liu Ruixuan , Liu Tianyi , Chakraborty Avirup , Hou Alicia Y , Petit Nicole A , Von Roemeling Christina , Lin Tuo , Davis Robert W , Zhang Janie , Pepe Alfonso , Pedro Diego Ivan , Mendez-Gomez Hector , Weidert Frances , Jin Dan , Long-James Kaytora , Castillo Paul C , Ligon John A , Ghiaseddin Ashley , Sayour Elias J , Rahman Maryam , Deleyrolle Loic P , Kim Betty Y S , Mitchell Duane A , Sawyer W Gregory , Huang Jianping 
Published: November 2024

Abstract

BACKGROUND
Recent evidence indicates that tumor-associated myeloid cells (TAMCs), including tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), play a crucial role in glioblastoma (GBM) immunosuppression and progression. These cells can constitute up to 50% of the total mass in GBM tumors and are pivotal in dampening the immune response, which negatively impacts patient survival. Targeting TAMCs represents a promising strategy to overcome the limitations of current cancer treatments. However, drug development in this area remains limited. Our study focuses on Leukocyte-Associated Immunoglobulin-like Receptor 1 (LAIR1), a novel immune checkpoint overexpressed on TAMCs within GBM. We comprehensively analyze LAIR1’s inhibitory role in cancer progression, highlighting its potential as a therapeutic target.

METHODS
Both in vitro and in vivo experiments were conducted. LAIR1 wild-type (LAIR1+/+) and knock-out (LAIR1-/-) tumor models were tested for antitumor response and intratumoral immune landscape. We also utilized 2D and 3D cultures to evaluate the effects of antibody blockade (aLAIR1) alone and in combination with CAR-T therapy (8R-70CAR) in both human and mouse GBM models.

RESULTS
We have uncovered a previously unrecognized immunosuppressive LAIR1→ Factor XIII A (FXIII-A)→ Collagen IV circuit across cancer types. Inhibiting LAIR1, either through genetic LAIR1-/- or aLAIR1, effectively disrupts this immunosuppressive pathway and results in enhanced peripheral and tumor-infiltrating memory CD8 T cell populations, a phenotypic shift of TAMs towards an M1 profile, and a decrease in tumor collagen deposition. These collective effects contribute to the normalization of the TME and facilitate improved interactions between T cells and tumor cells, leading to a more effective antitumor response. Notably, using aLAIR1 as a standalone intervention or combined with CAR T cell therapy demonstrates enhanced antitumor efficacy in preclinical models resistant to chemo-radiation and anti-PD-1 treatments.

CONCLUSIONS
We discovered a novel mechanism by which LAIR1 contributes to GBM progression. LAIR1 blockade holds promise in reversing suppressive TME and serving as a therapeutic strategy.
EXTH-59. ESTABLISHING GAUSSIA LUCIFERASE REPORTER AS A BIOMARKER FOR ESTIMATING THERAPEUTIC RESPONSE AND PROGRESSION-FREE SURVIVAL IN PATIENT-DERIVED XENOGRAFT MODELS OF GLIOBLASTOMA
Authors: McKinney K’Ashé , Tse Christopher , Wang Chencai , Sanvito Francesco , Nathanson David , Ellingson Benjamin M 
Published: November 2024

Abstract
Serial monitoring of tumor burden in patient-derived xenograft (PDX) models used for testing new cancer drugs via MRI and other imaging techniques can be costly. We theorized that transducing the Gaussia luciferase (GLuc) reporter gene into glioma PDX models (GliomaPDOX) allows for GLuc to be used as a biomarker for tumor burden. This current study investigates whether changes in the rate of GLuc secretion over time (i.e., “growth rate” changes) can predict survival in GliomaPDOX. Optimal cutoff values to define disease progression via GLuc measurements were established resulting in a strong association between progression-free survival (PFS) and overall survival (OS). The pLenti-CMV-sGluc-T2A-EGFP plasmid was packaged into a second-generation lentiviral system via HEK293FT cells, and the resulting virus transduced into directly-isolated glioma patient cells to establish the MGMT-Unmethylated and MGMT-Methylated GliomaPDOX. MGMT-Unmethylated GliomaPDOX were treated with placebo or Temozolomide (TMZ) until endpoint. MGMT-Methylated GliomaPDOX were treated with placebo or TMZ for three weeks or TMZ for six weeks until endpoint. Treatment response was monitored through GLuc measurements obtained via tail blood collection. The optimal cutoff for time to progression was a 30% increase in GLuc, which yielded a significant positive association between PFS and OS across all models and treatments (R2 = 0.8177, p&lt;0.0001). Compared to the MGMT-Methylated placebo and MGMT-Unmethylated groups, the MGMT-Methylated treatment groups exhibited substantial changes in GLuc growth rates and significantly longer PFS and OS (p&lt;0.0001). More specifically, the six-week MGMT-Methylated TMZ-treated group demonstrated a significant difference in GLuc growth rates and a considerable PFS (p&lt;0.0038) and OS increase (p&lt;0.0049) when compared to the three-week MGMT-Methylated TMZ-treated group. Therefore, GLuc measurement is a valuable biomarker for PDX tumor burden and can be used to estimate treatment response and PFS.
EXTH-65. EXPLORING ANTIHISTAMINES TO TREAT GLIOBLASTOMA
Authors: Yadav Poonam , Vengoji Raghupathy , Doss David , Jain Maneesh , Batra Surinder , Shonka Nicole 
Published: November 2024

Abstract

BACKGROUND
Glioblastoma (GBM) is an aggressive and lethal primary malignant brain tumor with a 5-year survival of 6.8%. Interestingly, people with allergies, atopy, or asthma are less likely to develop GBM. A recent study recognized that high histamine receptor 1 (HRH1) expression is inversely related to overall and progression-free survival.

METHODS
We used a bioinformatics tool, iLINCS, which, after analyzing 99 GBM and 38 healthy samples, identified 36 drugs that can reverse GBM signatures. Based on the concordance score and blood-brain barrier permeability, we selected brompheniramine (Brom), a first-generation HRH1 antagonist, as a potential candidate. HRH1 expression analysis was done on human and mouse GBM cell lines by immunoblotting. The effect of Brom alone or in combination with temozolomide (TMZ) was investigated on proliferation, DNA damage and apoptosis in human (U118 and U251) and three syngeneic (EGFRvIII, p16-/- & GFAP Cre, PTEN+/-, p53R172H+/-, EGFRvIII & GFAP Cre, PTEN-/-, p53R172H-/- & GFAP Cre) cell lines. GBM orthograft mouse models were used to test the efficacy of combination therapy.

RESULTS
HRH1 is highly expressed in human and syngeneic GBM cells. This expression is further increased in TMZ-resistant cells. Interestingly, the addition of histamine, induced TMZ resistance in GBM cells. TMZ with Brom decreases proliferation in mouse and human GBM cells, and Brom is non-toxic to non-transformed cells. Combination treatment increases DNA damage and decreases the DNA repair mechanism, possibly by downregulating the expression of O6methylguanine-DNA methyltransferase (MGMT). In the GBM orthograft mouse model, the combination therapy reduced tumor volume and significantly increased survival compared to single-agent treatment.

CONCLUSIONS
Brom is non-toxic; Brom, in combination with TMZ, enhanced the anti-tumor efficacy of TMZ both in in vitro and in vivo GBM models. Further studies in spontaneous mouse models are planned.
EXTH-72. INTEGRATED MULTIOMIC ANALYSIS OF ISOGENIC EGFRVIII MODELS OF GBM REVEALS EXPLOITABLE THERAPEUTIC VULNERABILITIES
Authors: Lin Benjamin , Shelton Abigail , Skinner Kasey , Smithberger Erin , Ziebro Julia , Bash Ryan , Angus Steven , East Michael , Johnson Gary , Furnari Frank , Miller C Ryan 
Published: November 2024

Abstract
Glioblastoma (GBM) is the most common primary malignant brain tumor with an abysmal 15-month median survival. Therefore, novel therapeutic interventions are urgently needed. EGFR is a receptor tyrosine kinase that is mutated in over 50% of GBM and is a logical target for precision oncology approaches. While aberrant EGFR signaling has been successfully targeted in other cancers, early attempts to target EGFR in GBM clinical trials have not been successful. Since these early trials, several studies have revealed that GBM EGFR biology is unique and cannot be generalized from other EGFR-driven neoplasms. To better understand EGFR biology in a GBM-specific context, we have characterized the GBM transcriptome with RNAseq, the epigenome with CUT&RUN, and the kinase proteome with Multiplexed inhibitor beads with Mass Spectrometry (MIB-MS), collectively referred to as ‘multiomics’, after modeling EGFR resistance. An isogenic mouse astrocyte (mAc) model of GBM was genetically engineered to overexpress EGFRvIII (CEv3), the most common EGFR mutation in GBM. Expression of EGFRvIII induces a unique multiomic profile that mediates many hallmark cancer phenotypes including proliferation and stemness. Chronic EGFR resistance was modeled both in vitro and in vivo through continuous exposure to erlotinib or gefitinib, EGFR tyrosine kinase inhibitors (TKI). Additionally, acute EGFR resistance was modeled using a single exposure to EGFR TKI afatinib or neratinib in vitro over a 48-hour time course. Preliminary multiomic characterization of these data has revealed several targets that can be further investigated for therapeutic exploitation. Further investigation into these targets using orthotopic allografts with CEv3 cells shows that combinatorial therapy with neratinib and abemacilib, a CDK inhibitor, significantly (p &lt; 0.001, n= 20 mice per group) extends survival (56 days) compared to neratinib alone (31.5 days). Future integrated multiomic analysis aims to elucidate the synergistic relationship between neratinib and abemacilib.