bluuebunny/crossref_metadata_2025_split huggingface dataset:
TMIC-31. MOLECULAR PROGNOSTIC FACTORS OF THE PROGRESSION OF VESTIBULAR SCHWANNOMA AFTER PRIMARY TUMOR RESECTION
Authors: Mizuta Ryo , Makino Keigo , Otai Yoshihiro , Fujii Kentaro , Ishida Joji , Uneda Atsuhito , Tsuboi Nobushige , Hirano Shuichiro , Kemmotsu Naoya , Suruga Yasuki , Imoto Ryoji , Kegoya Yasuhito , Hokama Madoka , Ikemachi Ryosuke , Matsumoto Yuji , Tomita Yusuke , Shimazu Yosuke , Inoue Hirofumi , Yan Yuanqing , Wang Ziyi , Ono Mitsuaki , Kurozumi Kazuhiko , Ichikawa Tomotsugu , Yasuhara Takao , Tanaka Shota 
Published: November 2024

Abstract

BACKGROUND
Although vestibular schwannoma is a benign tumor, 10% of the tumor regrow after primary tumor resection. The factors associated with tumor progression from several reports remain controversial, and the role of the tumor microenvironment in vestibular schwannoma is still unclear. In this study, we analyzed the prognostic factors associated with the tumor progression after primary resection.

METHODS
We retrospectively reviewed the medical records of patients who underwent surgical resection and were diagnosed with vestibular schwannoma between January 2005 and June 2020. We performed RNA sequencing to identify the prognostic factors and immunohistochemistry to assess the tumor microenvironment, including analysis of the CD80 and CD206 expression of macrophages. We compared the progressed group whose tumor size got larger than 2mm after primary resection or who underwent additional treatment because of regrowth with the stable group.

RESULTS
Fifty-five patients underwent surgical resection for newly diagnosed vestibular schwannoma, and 12 of them had tumor regrowth. RNA sequencing revealed that the significantly upregulated pathways in the stable group was related to immune systems, while that of the progressed group was related to cell cycle. In addition, there were more myeloid cells, especially M2 macrophage infiltration in the stable group. Immunohistochemistry also showed higher M2 macrophages in the stable group.

CONCLUSION
In this study, multiomic analysis revealed the upregulation of immune-related pathways in the stable group and the cell cycle pathway in the progressed group. Altering the tumor microenvironment may offer a therapeutic strategy in vestibular schwannoma after primary resection.
TMIC-36. EVALUATING PHARMACOLOGICAL INHIBITION OF LSD1 IN MODELS OF DIFFUSE MIDLINE GLIOMA AND EFFECTS ON IMMUNE MICROENVIRONMENT SIGNALING
Authors: Nam Deokhwa , Hernandez Faith , Stitzlein Lea , Becher Oren , Chandra Joya 
Published: November 2024

Abstract

BACKGROUND
Diffuse midline glioma (DMG) is the leading cause of death for pediatric brain tumor patients. DMG is remarkably immunologically senescent, even in comparison to other “immune-cold” tumors like adult glioblastoma. Lysine specific demethylase-1 (LSD1) is a histone demethylase exerting context-specific mechanisms of gene repression and activation and can be inhibited pharmacologically. We found LSD1 regulates the expression of inflammatory cytokines such as Interleukin 18 (IL18) and immune signaling receptors in DMG. Here, we investigated whether IL18 is transcriptionally regulated by LSD1 in vitro and in vivo using clinically relevant small molecule inhibitors.

METHODS
LSD1 binding to the IL-18 promoter was evaluated using chromatin immunoprecipitation. Transcript and protein expression using qRT-PCR and western blotting assessed the impact of LSD1 inhibition on IL18-related pathways and immune signaling pathways. LSD1 inhibitors (IMG-7289 or GSKLSD1) were evaluated patient-derived xenograft models. Results. We found elevated LSD1 binding on the IL18 promoter in DIPG VI cells. Subsequent qRT-PCR and western blot analyses demonstrated increased IL18 protein levels following treatment with GSKLSD1 or IMG-7289 in DIPG VI cells, alongside heightened IL18 mRNA expression compared to DMSO-treated cells. Either GSKLSD1 or IMG-7289 treatment in DIPG IV cells also led to significantly elevated IL18 binding protein mRNA levels. Orthotopic xenografts using DIPG IV bearing mice dosed with LSD1 inhibitors over the course of 35 days several weeks showed a decrease in IL-18R, and an increase in IL-18 BP transcript levels alongside a significant increase in Slamf7 transcript levels. Some evidence of tumor inhibition was seen in male but not female mice treated with GSKLSD1.

CONCLUSIONS
Our investigation revealed IL18 as a direct target of LSD1 specifically in DIPG VI, and gender specific effects of GSKLSD1 treatment in vivo. Future studies will prioritize validating and elucidating the underlying mechanisms the therapeutic potential of LSD1 inhibition in DMG.
TMIC-37. GEMISTOCYTIC TUMOR CELLS AND IMMUNE REACTIVE MICROGLIA PROGRAMMED FOR GLIAL SCARRING CHARACTERIZE T CELL CONTAINMENT IN IDH-MUTANT ASTROCYTOMA
Authors: van Hijfte Levi , Geurts Marjolein , de Heer Iris , Ghisai Santoesha , Balcioglu Hayri , Hoogstrate Youri , Vallentgoed Wies , Head Rania , Westerman Bart , Wesseling Pieter , Joyce Johanna , Debets Reno , French Pim 
Published: November 2024

Abstract
Isocitrate dehydrogenase 1/2 mutant (IDHmt) astrocytoma is considered a T cell-deprived tumor, yet little is known regarding the phenotype that relates to T cell exclusion. To aid better understanding of this mechanism, we systematically characterized the IDHmt astrocytoma immune microenvironment in a large cohort by multiplex immunofluorescence (IF) (n=75), bulk RNA sequencing (n=158), single nucleus RNA sequencing (n=7) and spatial RNA and protein profiling (n=12). We integrated and analyzed all datasets to acquire a robust characterization of the microenvironment organization and validated our results using IF stainings. We demonstrated that in IDHmt astrocytomas, T cells were contained in the perivascular space (i.e., T cell cuffs). In the tumor stroma surrounding T cell cuffs, we found a dense accumulation of gemistocytic tumor cells (GTCs), a histologically distinct tumor cell subtype. GTC-high tumors demonstrated enhanced expression of immune cell migration and activation pathways that were reliably expressed by TAMs and T cells. Notably, we found that GTCs formed a unique transcriptional cell sub-cluster that expressed markers including CD44, TNC and CRYAB, which are specific for glial scarring, a central nervous system specific mechanism for immune exclusion. Surrounding T cell cuffs, GTCs co-localized with immune-reactive microglia that expressed the chemoattractants CCL3 and CCL4. Together, co-localizing GTCs and reactive microglia expressed receptor-ligand pairs that take part in reactive astrogliosis and glial scarring, including Osteopontin – CD44 and IL-1β – IL1R1. Validation whole-slide multiplex IF stainings for this spatial relationship showed specific local accumulation of CD44 positive GTCs and TAMs around T cell cuffs in GTC-high tumors, which was absent in GTC-low tumors. Together, we show that IDHmt astrocytomas organize a network of tumor cells and leukocytes that mimics glial scarring and can aid T cell exclusion. Elucidating such specific immune exclusion mechanisms is vital for more appropriate target selection in novel immune therapies.
TMIC-41. RBBP4/P300 COMPLEX CONTROLS GENES MODULATING ANGIOGENESIS AND IMMUNOSUPPRESSION IN GLIOBLASTOMA MICROENVIRONMENT
Authors: Mapunda Josephine , Htee Hser , Wang Li , Mortazavifarsani Seyedehsahar , Suzuki Yuta , Verma Vivek , Hoeppner Luke , Sarkaria Jann , Kitange Gaspar 
Published: November 2024

Abstract
The RBBP4/p300 complex was recently shown to control genes critical for DNA damage repair and may play a role in glioblastoma (GBM) therapy responsiveness, especially to temozolomide (TMZ). However, the role of this complex in the modulation of the GBM tumor microenvironment (GBM-TME) remains elusive. Because pro-tumorigenic GBM-TME is primarily due to angiogenesis and immune tolerance, we evaluated whether the RBBP4/p300 complex may control these critical processes. To that end, we used shRNA to silence each RBBP4/p300 complex member in GBM43 cells and RNAseq to identify angiogenesis and immune genes regulated by this complex. Our data demonstrated that silencing RBBP4 or p300 suppressed the expression of HIF1α and several other hypoxia response genes, including VEGFA and DDIT4, suggesting that RBBP4/p300 complex may regulate angiogenesis. Consistent with a role in regulating angiogenesis, culture medium conditioned by GBM43 cells expressing the control non-targeting shRNA (shNT) significantly induced angiogenic tube formation by human umbilical vein endothelial cells (HUVEC). In contrast, this effect was blocked by the medium conditioned by the shRBBP4 or shp300 expressing cells. Both shRBBP4 and shp300 expressing cells failed to activate HIF1α accumulation and other signaling in response to hypoxia. Additionally, the control shNT-conditioned medium inhibited IFN-γ production while the medium conditioned by the shRBBP4 or shp300 expressing cells supported IFN-ɣ production from CD8+ T cells. Intriguingly, silencing RBBP4 or p300 also suppressed the expression of CCL2 and PD-L1 (CD274). CCL2 protein is a chemokine that promotes TME infiltration by myeloid-derived suppressor cells (MDSCs), while PD-L1 interacts with PD1 to suppress cytotoxic CD8+ T cell activation. Although this is an ongoing investigation, we conclude that RBBP4/p300 complex mediates the expression of hypoxia response genes, including HIF1α, and immunosuppressive genes, including PD-L1, and this activity may enhance angiogenic and immunosuppressed GBM-TME, making this complex a potential target for GBM therapy.
TMIC-46. TRANSCRIPTIONAL HETEROGENEITY AND MECHANISTIC PATHWAYS OF RECURRENT GLIOBLASTOMA: INSIGHTS FROM A PRE-CLINICAL RECURRENT TUMOR MODEL
Authors: Fayyad Zaman Mohammad , Daou Marc , Phillips Lynette M , Singh Sanjay , Long Lihong , Gumin Joy , Ledbetter Daniel , Lang Frederick F 
Published: November 2024

Abstract
Despite aggressive therapy combining surgical resection, radiation and chemotherapy, glioblastoma (GBM) almost always recurs. Currently, there is no standard treatment for recurrent GBM, and patient inclusion in clinical trials is based on the genetic and molecular profile of the primary tumor even though the effects of chemoradiation on the transcriptional subtype in matched primary and recurrent GBM remain largely understudied. Paralleling the GLASS consortium, we sought to perform a longitudinal assessment of GBM recurrence after therapy based on molecular subtype with the hypothesis that recurrent tumors exhibit a distinct transcriptional landscape different from treatment-naive tumors. To address this, we utilized primary tumor-derived glioma stem cells (GSCs) representing classical and proneural subtypes. We then undertook in vivo intracranial implantation studies and performed standard concomitant treatment that mimics the Stupp protocol. Upon bulk RNAseq data analyses of untreated (n=21) and recurrent tumors (n=17) we identified that while the molecular subtype of recurrent tumors does not change post therapy, their transcriptional profile is more heterogenous compared to untreated tumors for both subtypes. Hierarchical cluster analyses revealed distinct sub-clusters of recurrent tumors. Common mechanisms of recurrence include upregulation of angiogenesis pathways and PI3k/Akt/mTOR signaling pathways. Interestingly, recurrent tumors exhibit upregulation of genes involved in cellular metabolism and membrane transport/ potential. The source of heterogeneity in recurrent tumors in both subtypes appears to be due to the diversity in expression of gene sets involved in hallmark of cancer pathways such as cell cycle, Notch and Wnt signaling pathways and heterogeneity in oncogenic signatures and cell states resembling fetal or neural cells. Further research into the recurrent tumor microenvironment by spatial multi-omics approaches using this pre-clinical recurrent GBM model will elucidate the linkage between cellular as well as molecular heterogeneity and enable identification of targets that can help drive therapeutic decisions for recurrent GBM patients.
TMIC-62. INVESTIGATING THE ROLE OF OSTEOPONTIN IN RADIORESISTANCE OF H3.3-G34R PEDIATRIC HIGH-GRADE GLIOMA
Authors: Mukherji Devarshi , Haase Santiago , Varela Maria Luisa , Welch Joshua , Lowenstein Pedro , Castro Maria 
Published: November 2024

Abstract
Pediatric high-grade gliomas (pHGGs) are currently the leading cause of cancer-related deaths in children. Around 15% of pHGGs harbor a glycine to arginine (G34R) mutation in histone H3.3. Gliomas in general, including H3.3-G34R gliomas, contain cell populations that are resistant to chemotherapy and radiation therapy. These resistant cell populations are responsible for tumor recurrence seen in over 90% of patients within two years after treatment. Uncovering molecular mechanisms responsible for radiation resistance is essential for the development of new targeted therapies against glioma. In our lab’s H3.3-G34R mouse model, we have observed mice that are both radioresistant and radiosensitive. In order to investigate potential mechanisms of resistance leading to this phenotype, we performed single-cell RNA sequencing (scRNA-seq) on 3 non-treated (NT) glioma-bearing mice, 3 mice resistant to treatment (R), and 3 mice susceptible to treatment (S). The scRNA-seq data was processed and filtered using FastQC, Cellranger, CellBender, and DoubletFinder before downstream analysis. Ligand-receptor interaction analysis using CellChat in conjunction with differential expression analysis demonstrated differential expression and secretion of a cytokine known as Secreted Phosphoprotein 1 (SPP1)/Osteopontin (OPN) from tumor-associated microglia and macrophages. Current literature on SPP1 has suggested that its expression may play a role in tumor aggressiveness. However, there is conflicting evidence regarding its mechanism of action when secreted from tumor-associated microglia and macrophages. Additionally, its role in radioresistance has yet to be fully explored. We will present data utilizing in vitro and in vivo experimentation to elucidate the role that differential expression of SPP1 may play in the radioresistance of our H3.3-G34R mouse model. Supported by grants from NIH-NINDS, the Pediatric Brain Tumor Foundation, and Ian’s Friends Foundation
TMIC-63. DUAL IMMUNE CHECKPOINT BLOCKADE IN A NOVEL EGFR-DRIVEN MURINE GLIOMA MODEL INCREASES PERIPHERAL T CELL PROLIFERATION BUT FAILS TO PROLONG SURVIVAL
Authors: Li Marissa , Pioso Marissa , Breunig Joshua , Grausam Katie , Nathanson David , Prins Robert 
Published: November 2024

Abstract
Patients with glioblastoma (GBM) survive only 15-18 months following standard-of-care surgical resection and radio-chemotherapy. Immune checkpoint blockade (ICB), effective in extracranial cancers, failed to improve survival in patients with recurrent GBM in a multi-center phase III clinical trial. As such, we are interested in the molecular mechanisms that drive ICB resistance. Oncogenic EGFR activation is observed in ~50% of GBMs and is associated with immunosuppression; however, whether EGFR signaling impairs T cell function in GBM resulting in limited ICB efficacy remains unclear. Therefore, we leveraged the novel MADR-mEGFRvIII glioma model, which expresses murine EGFRvIII under a tetracycline-off system, to investigate the relationship between EGFR activation and responsiveness to dual anti-PD-1 and anti-CTLA-4 (10mg/kg) in vivo. Mice were bled prior to enrollment and weekly thereafter, which confirmed anti-PD-1-PD-1 binding via competitive flow cytometric assay. Following two weeks on treatment, animals were euthanized for immunophenotypic analyses of tumors and tumor-draining lymph nodes. These analyses revealed a significantly increased prevalence of peripheral CD11b+ myeloid cells and enhanced peripheral T cell proliferation, indicated by Ki67 positivity, after treatment with dual ICB compared to isotype control. However, these shifts did not translate to effective ICB-mediated recruitment of peripheral T cells to the tumor microenvironment and no significant survival benefit was observed (p=0.68, n=15/treatment arm). Given our previous findings that EGFR ablation via doxycycline enhanced intratumoral T cell infiltration, we hypothesize the rational combination of EGFR-targeted therapy and ICB will have a synergistic effect; thus, future directions include a study combining the two treatment regimens consisting of a lead-in with doxycycline to increase intratumoral T cell trafficking, followed by treatment with dual ICB. This work will provide insight into the interplay between oncogenic signaling and immunosuppression, contributing to the development of novel combination therapies in treating this lethal disease.
TMIC-67. EMERGING ROLE OF EXTRACELLULAR MATRIX STIFFNESS AS A HALLMARK OF GLIOBLASTOMA: INSIGHT TO MECHANICAL MEMORY FORMATION AND PROLONGED INVASION IN THE TUMOR PERIPHERY
Authors: Suarez Meade Paola , Whitehead Rachel , Clemenceau Jean , Norton Emily , Kulkarni Tanmay , Hong Changjin , Teeter Caroline , Aramburu Manuela , Chaichana Kaisorn , Rosenfeld Steven S , Kenchappa Rajappa , Guerrero-Cazares Hugo , Schiapparelli Paula V , Hwang Tae H , Konstantopoulos Konstantinos , Quinones-Hinojosa Alfredo 
Published: November 2024

Abstract

The extracellular matrix (ECM) plays a critical role in cancer progression, with its biophysical properties influencing cancer behavior. ECM stiffness can induce long-lasting adaptations in cancer cells, promoting sustained invasion through a process known as “mechanical memory” (MM). Glioblastoma (GBM) exhibits spatial heterogeneity in stiffness, with stiffer ECM found at the tumor periphery where invasive cells reside and promote recurrence. We hypothesize that increased stiffness at the tumor periphery primes GBM cells for sustained invasion through MM.

METHODS
Cell lines were established from image-guided human GBM samples from tumor margin and core (n=10 patients, 20 cell lines). Cells from random locations were conditioned in physiologically relevant extracellular matrices for two weeks. Human organotypic assay (n=3), Migration Assays, Atomic Force Microscopy (AFM), Immunocytochemistry, Western Blot, and RNA-sequencing (n=6) were performed.

RESULTS
GBM cells at higher stiff surfaces displayed increased migration (p&lt;0.01). Magnetic Resonance Elastography (n=9) confirmed GBM heterogeneity, with softer cores (0.2-0.5kPa) transitioning to stiffer margins (&gt;2kPa). Organotypic scaffolds mimicking the tumor margin promoted enhanced migration of GFP-labeled GBM cells. Margin cells and cells conditioned on stiffer matrices demonstrated higher migratory potential compared to their core and soft-conditioned counterparts (p&lt;0.05). These trends persist over time and across multiple passages. ECM stiffness exposure causes nanomechanical, cytoskeletal, and transcriptional adaptations. AFM shows that cells from the margin (n=6) are softer (p&lt;0.01) and more deformable (p&lt;0.01). RNAseq identified upregulation of MM-specific genes in GBM margin cells. The mechanosensitive transcription factor YAP1 emerged as a key driver of MM. Notably, YAP1 is targetable by the FDA-approved drug Verteporfin. YAP1 expression was elevated in margin and stiff-conditioned cells (p&lt;0.05). Stiff-conditioned cells and margin cells displayed increased sensitivity to Verteporfin treatment (p&lt;0.05), with treatment significantly reducing margin migration compared to the core (p&lt;0.001).

CONCLUSION
Stiffer GBM margins promote the formation of aggressive phenotypes through MM. Targeting YAP1 with Verteporfin, a readily available drug, presents a promising strategy to halt GBM invasion and improve patient outcomes.
TMIC-70. CORRELATION OF LLT-1 AND NLRC4 INFLAMMASOME AND ITS EFFECT ON GLIOBLASTOMA PROGNOSIS
Authors: Park JeongMan , Kim Yu Jin , Kim Dongkil , Sim JeongMin , bog Cho Kwang , cho Kyunggi , Moon Ju Hyung , Sung Kyoung Su , Lee Dong Hyun , Lim Jaejoon 
Published: November 2024

Abstract

PURPOSE
LLT-1 is a well-known ligand for the natural killer (NK) cell inhibitory receptor NKRP1A. Here, we examined NLRC4 inflammasome components and LLT-1 expression in glioblastoma (GBM) tissues to elucidate potential associations and interactions between these factors.

METHODS
Nine GBM tissues were collected for experiments and RNA sequencing, while fifty-two tumor core tissues were collected for RNA sequencing. Expression of LLT-1 and other proteins was assessed by immunofluorescence. Computational analyses utilized RNA-seq data from 296 and 52 patients from the Chinese Glioma Genome Atlas and CHA medical records, respectively, using survival, non-negative matrix factorization clustering, Gene Ontology enrichment, and protein-protein interaction analyses. Receptor-ligand interactions between tumor and immune cells were confirmed by single cell RNA sequencing analysis.

RESULTS
In GBM tissues, LLT-1 was predominantly colocalized with Glial fibrillary acidic protein (GFAP) -expressing astrocytes, but not with microglial markers like Iba-1. Additionally, LLT-1 and activated NLRC4 inflammasomes were co-expressed mainly in intratumoral astrocytes, suggesting an association between LLT-1, NLRC4, and glioma malignancy. High LLT-1 expression correlates with poor prognosis, particularly in the mesenchymal subtype, and is associated with TNF and NOD-like receptor signaling pathway enrichment, indicating a potential role in tumor inflammation and progression. At the single-cell level, mesenchymal-like malignant cells were highly enriched in the TNF, NLR, and IL-1 signaling pathways compared to other malignant cell types.

CONCLUSION
We revealed an association between NLRC4 inflammasome activity and LLT-1 expression, suggesting a novel regulatory pathway involving TNF, inflammasomes, and IL-1, potentially offering new anti-glioma approaches by enhancing NK cell-based treatments.
TMIC-72. MECHANISMS TO ENHANCE IMMUNOTHERAPY EFFICACY IN A RAT MODEL OF MEDULLOBLASTOMA
Authors: Stateler Cooper , Holland Samantha , Stoller Jared , Wongsawaeng Doonyaporn , Muldoon Leslie , Neuwelt Edward , Ambady Prakash , Barajas Ramon 
Published: November 2024

Abstract
Medulloblastoma is the most common malignant brain tumor in children. Current treatments are limited by irreversible CNS damage, particularly in high-risk subgroups. Innate immune cells constitute a significant portion of the brain tumor microenvironment, nurturing tumor growth and suppressing key defense mechanisms. Leveraging the innate immune system for improved clinical outcomes remains unrealized. We aimed to determine if Baicalein (Bac), a known tumoricidal M1 macrophage potentiator, improves efficacy in medulloblastoma models. Nude rats (N=10) were implanted with MB002 medulloblastoma intracerebellar patient-derived non-WNT/non-SHH, group 3 xenografts. Baseline T2 and gadolinium-enhanced MRI (Gd-MRI) T1 estimated pre-therapy tumor volumes. Single fraction 2Gy irradiation to the tumor-bearing hemisphere with 20mg/kg temozolomide (CRT) combined with Bac 100mg/kg PO QD daily x8 (N= 3) was administered. CRT alone (N= 3) and no treatment (N= 4) served as controls. Seven days post-therapy, Gd-MRI and histology established tumor volume and CD68 and CD163 expression (T-test; p≤ 0.05). MRI demonstrated the therapeutic effect of Bac+CRT compared to CRT only (P&lt; 0.01) and untreated controls (P= 0.01). This was confirmed via histology volumes; untreated group (P&lt; 0.01) and a trend toward significance vs. CRT only (P= 0.22). The normal brain demonstrated a near significant increase in CD68 expression in the Bac+CRT compared to CRT and control (P&lt; 0.06). A near statistically significant decrease in CD163 expression was observed at the tumor margin for Bac+CRT compared to CRT only (P&lt; 0.06). Likewise when comparing CRT to untreated control (P&lt; 0.05). Preliminary data suggests Bac+CRT uniquely induces an innate immune response within the brain that expresses features of M1 polarization, resulting in effective tumoricidal efficacy in preclinical medulloblastoma models. Current studies are evaluating the mechanisms of efficacious innate immune targeted therapies in larger sample sizes with the eventual goal of clinical translation.