bluuebunny/crossref_metadata_2025_split huggingface dataset:
TMIC-14. CLEC5A REGULATES TAM POLARIZATION, TME IMMUNOSUPPRESSION AND DISEASE PROGRESSION IN GLIOBLASTOMA
Authors: Li Jiabo , Wang Xuya , Tong Luqing , Markwell Steven , Shih Ling-Kai , Olson Cheryl , Carneiro-Lobo Tatiana , Yang Xunjun , Brat Daniel 
Published: November 2023

Abstract
Glioblastoma, IDH-wildtype (WHO grade 4) is the most common primary malignant brain tumor of adults and is characterized by an immunosuppressive tumor microenvironment (TME) and poor clinical outcomes. CLEC5A is a gene whose expression enhances immune response in inflammatory and infectious diseases, yet its role in GBM immune regulation is unclear. Seurat analysis of scRNA-seq data and CIBERSORTx analysis of GBM RNA-seq data showed that tumor-associated macrophages (TAMs) account for the large majority of immune cells in the GBM, and that CLEC5A expression in this population (CD163+) is highest in hypoxic, peri-necrotic zones. Notably, among all immunosuppressive TAM related genes, CLEC5A expression shows the strongest association with poor clinical outcomes. Monocytes (THP-1 cells) exposed to GBM conditioned media exhibit enhanced CLEC5A and CD163 expression. Moreover, overexpression of CLEC5A by THP-1 cells enhances TAM polarization, migration toward glioma cells, and increased secretion of cytokines that mediate immunosuppression, including IL-1β, IL-4, IL-6, IL-8, IL-10 and IL-13. CLEC5A triggers the activation and phosphorylation of the Syk-Jak2-STAT3 signaling through its interaction with Syk, offering a potential therapeutic intervention. In addition, CLEC5A acts as a receptor, binding to Podoplanin (PDPN) expressed on GBM cells in the peri-necrotic TME, triggering CLEC5A-Syk-JAK-STAT3 signaling and highlighting their role in TAM polarization and the immunosuppressive TME. In vivo, silencing CLEC5A delayed glioma growth, prolonged survival and was associated with reduced CD163 and neoplastic Ki-67 expression. Collectively, we found that CLEC5A expression by TAMs is regulated by PDPN-CLEC5A-Syk-JAK-STAT3 signaling and enhances TAM polarization, TME immunosuppression and GBM growth.
TMIC-15. GENETIC AND SPATIAL HETEROGENEITY OF PEDIATRIC HIGH-GRADE GLIOMAS CONFER UNIQUE INFLAMMATORY MICROENVIRONMENTS
Authors: Ross James , Pinero Gonzalo , Puigdelloses-Vallcorba Montserrat , Soni Nishant , Angione Angelo , Becher Oren , Tsankov Alexander , Hambardzumyan Dolores 
Published: November 2023

Abstract
Significant progress has been made molecularly defining pediatric high-grade gliomas (pHGG), including diffuse midline gliomas (DMG), yet little progress has been made with respect to delineating the inflammatory microenvironment. We utilize molecularly defined human samples and immunocompetent genetic mouse models to study how tumor location and genetic driver mutations influence the tumor microenvironment (TME). We report human DMGs have a significant enrichment of Elane+ neutrophils compared to their hemispheric counterparts. We validate this utilizing the RCAS-Tva mouse model, which histologically and genetically recapitulates human pHGGs. Using this model we demonstrate each distinct pHGG/DMG entity confers unique transcriptional identities as made evident by NanoString RNA expression profiles and whole-tumor single-cell RNA sequencing. H3.3WT DMGs and H3.3K27M DMGs cluster together and have high expression of inflammatory genes such as Ptprc, Trem2, Lag3, and Cd274 while H3.3WT and H3.3G34R hemispheric tumors, and H3.1K27M DMGs cluster together with low expression of these genes. Several genes were found to significantly correlate with median survival in human bulk RNA sequencing data including IL13RA2. Flow cytometry and immunohistochemistry demonstrate H3WT DMGs are enriched for monocytes and lymphocytes while H3.3K27M DMGs are enriched for microglia. Genetic perturbations were made to prevent TAM or neutrophil infiltration, including targeting Ccl3, Cxcl1, and Ccl8/12. Only Ccl8/12 knockout resulted in significant extension of survival in H3K27M DMGs, which was met with an increase in CD4+ and CD8+ T-cells and decreased neutrophil infiltration. CD4+ T-cell depletion and anti-PD1 therapy was performed to further study the role of lymphocyte infiltration in DMGs. Lastly, CCR1/CCR5 inhibitors were utilized to abrogate TAM infiltration in DMGs, resulting in decreased microglia infiltration and significant survival extension comparable to radiation therapy. Together, this work provides the foundation for developing or improving immunotherapies designed at specific subgroups of pHGG and DMGs, such as CAR-T-cell, oncolytic viral therapy, and checkpoint blockade.
TMIC-17. THE ROLE OF ICAM1 IN GLIOBLASTOMA TUMORIGENESIS UNDER HYPOXIC CONDITIONS
Authors: Mansouri Sheila , Devaraja Kaviya , Zadeh Gelareh , Singh Olivia , Ali Hafsah , Wei Qinxqia , Sosa Julio , Patil Vikas 
Published: November 2023

Abstract
Glioblastoma (GBM) is a deadly brain cancer in adults with limited treatment options. Cell adhesion molecules (CAMs) mediate cell-cell interactions and migration. Intercellular adhesion molecule 1 (ICAM-1) is a CAM expressed by various cell types in solid tumors, including macrophages, tumor and endothelial cells. We previously demonstrated that ICAM-1 expression is linked to shorter overall survival in GBM patients. We observed elevated ICAM-1 levels in hypoxic regions of GBMs. Considering the role of tumor-associated macrophages (TAMs) in GBM tumorigenicity, our objective was to investigate how ICAM-1 expression in TAMs contributes to GBM growth within the hypoxic tumor microenvironment (TME). We employed a comprehensive approach utilizing in vitro and in vivo models, as well as genomic analyses at both bulk and single-cell levels, to elucidate the association between ICAM-1 and TAMs in tumorigenicity. Our findings demonstrated that injecting GBM cells into ICAM-1 knockout mice led to prolonged survival, smaller tumors, reduced macrophage infiltration, and enhanced M1-like polarization of TAMs. Additionally, bone marrow reconstitution experiments confirmed the tumor-promoting role of ICAM-1-expressing TAMs. Cell deconvolution, immunohistochemical, and flow cytometry analyses of mouse tumors supported these findings. Gene set enrichment analysis of differentially expressed genes in xenografted tumors revealed that ICAM-1 presence upregulated key tumorigenic pathways, including epithelial-mesenchymal transition, IL2-STAT5, TNF-α via NFκB, IL6-JAK-STAT3, and RAS/MAPK. In vitro analysis indicated that ICAM-1 promoted macrophage migration and polarization towards M2-like state, which was further augmented by hypoxia-induced ICAM1 expression. Flow cytometry, cytometry by time of flight (cyToF), and single-cell RNA sequencing analysis of human and mouse GBMs revealed elevated ICAM-1 expression in hypoxic TAMs, suggesting the hypoxic microenvironment promotes the tumorigenic functions of TAMs. In conclusion, ICAM1 likely enhances GBM tumorigenesis by promoting TAM migration into the TME. Furthermore, environmental factors such as hypoxia contribute to increased ICAM-1 expression in TAMs, further exacerbating GBM tumorigenicity.
TMIC-20. A SPATIALLY RESOLVED HUMAN GLIOBLASTOMA ATLAS REVEALS DISTINCT CELLULAR AND MOLECULAR PATTERNS OF ANATOMICAL NICHES
Authors: Shah Nameeta , Park Hyun Jung , Sonpatki Pranali , Han Kyung Yeon , Yu Hyeon Jong , Kim Shin Wook , Chowdhury Tamrin , Byun Yoon Hwan , Kang Ho , Lee Joo Ho , Lee Soon-Tae , Won Jae-Kyung , Kim Tae Min , Choi Seung Hong , Shin Young-Kyoung , Ku Ja-Lok , Lee Sungyoung , Yun Hongseok , Park Sung Hye , Park Chul-Kee , Park Woong-Yang 
Published: November 2023

Abstract
Glioblastoma (GBM) is a highly plastic ecosystem where the complex interplay between different cellular components contributes to disease progression. Although single-cell RNA (scRNA)-seq has revealed remarkable cellular heterogeneity of GBM, our knowledge regarding the spatial organization of its cellular components is currently lacking. Here we created a comprehensive dataset of 115,914 spatial transcriptomes across 32 tissue sections with matched multi-omics profiling on a set of genotyped glioma samples. We present spatial maps of 56 fine-grained cellular components, including previously unrecognized subtypes of oligodendrocytes and stromal cells, and their spatial interaction networks in each GBM- associated anatomical niche. Furthermore, the deconvolution of bulk RNA-seq data using the integrated spatial and single-cell atlas revealed clinically relevant GBM ecotypes. Our data provides comprehensive insights into the cellular architecture of GBM at high spatial resolution. It will be a valuable resource to develop effective combinatorial therapies to target all tumor-fostering niches simultaneously.
TMIC-21. SPHINGOSINE-1-PHOSPHATE RECEPTOR 3 (S1PR3) IN THE GLIOBLASTOMA TUMOR MICROENVIRONMENT MAY PLAY A ROLE IN IMMUNOSUPPRESSION
Authors: Michelhaugh Sharon , Munson Jennifer 
Published: November 2023

Abstract
Glioblastoma remains an intractable clinical problem with few efficacious treatments and poor patient outcomes because of the challenge in treating the tumor cells that have invaded into the normal brain. These invasive tumor cells typically remain after standard-of-care surgical resection and likely persist to generate recurrent tumors. In our previous studies of the glioma tumor microenvironment (TME), we identified sphingosine-1-phosphate receptor 3 (S1PR3) as upregulated in glioma TME regions with increased fluid flow. In order to efficiently study S1PR3 in the normal brain/ glioblastoma tumor interface, we engaged the Wake Forest University Brain Tumor Center of Excellence to construct a tissue microarray (TMA) including glioblastoma tissue cores specifically of the normal brain/ tumor interface as determined by pathologist review. The TMA included FFPE tissue cores from 42 GBM patients (average age 67.7 ± 10.9 years, 25 male, 17 female). Immunohistochemistry to detect S1PR3 was performed using an antibody that targets the amino-terminal domain followed by spatial profiling using neuroscience, neuroinflammation, and immune antibody panels (Akoya Biosciences). Preliminary analyses of the spatial profiling revealed 34 evaluable tissue cores, with no difference in the percentage of neurons, glial cells, vascular cells, or T cells between the S1PR3 positive and negative cores, however a significant difference in the percentage of M1 macrophages/ antigen presenting cells was found between the two groups (S1PR3-positive 0.646 ± 0.569%, n=13; S1PR3-negative 2.95 ± 3.28%, n=21, p=0.0178 two-tailed t-test. These findings suggest that the presence of S1PR3 may be associated with reduced M1 macrophages/ antigen presenting cells and therefore S1PR3 may contribute to glioblastoma tumor associated immunosuppression.
TMIC-22. IDENTIFICATION OF EXOSOME MIRNA-MRNA INTERACTIONS IN THE GLIOMA TUMOR IMMUNE MICROENVIRONMENT
Authors: Xu Emily , Krueger Katharine , Sussman Jonathan , Akca Ebrar , Matache Irina-Mihaela , Halthore Amitha , Patterson Jonathan , Amankulor Nduka 
Published: November 2023

Abstract

INTRODUCTION
Exosomes have emerged as key local and systemic immune modulators in glioma, particularly in tumors with an IDH mutation. However, the exact mechanism by which these vehicles communicate with the tumor immune microenvironment warrants further exploration. We sought to identify exosomal miRNA differences in discrete genomic subsets in glioma and predict potential mRNA targets in tumor immune cell populations.

METHODS
Exosomes were isolated from IDH wild-type (IDHwt) and IDH mutant (IDHm) glioma organoids using ultracentrifugation. Nanoparticle Tracking Analysis and western blot were used to validate exosome capture. Exosomal miRNA was sequenced using the Illumina Novaseq platform and targets were predicted using TargetScan. Peripheral blood mononuclear cells (PBMCs) were isolated from glioma patients and processed for scRNA-seq.

RESULTS
The characteristics of isolated exosomes were consistent with previously published data. Six miRNAs were over-expressed in IDHm exosomes compared to IDHwt. Interestingly, none of these miRNAs were significantly up-regulated in IDHm tumor tissue. Comparison between predicted targets of IDHm exosome miRNA and scRNA-seq of circulating tumor PBMCs identified a set of expressed genes involved in the FOXO pathway, which is implicated in microglia activation and polarization. Furthermore, scRNA-seq analysis showed that the FOXO3 pathway is activated in CD14+AREG+ monocytes and CD14+RNA-lo monocytes, which are two cell populations that are fractionally down-regulated in IDHm glioma.

CONCLUSION
Our group and others have defined mutation-dependent mechanisms of immunosuppression in glioma. Here, we characterized the effects of tumor mutational status on exosome miRNA cargo and conducted a miRNA-mRNA network analysis to identify potential targets in tumor-associated myeloid cells. Our results suggest that exosomes may play a role in suppressing specific populations of monocytes via the FOXO pathway in an IDH-mutation dependent manner. This data sets the stage for mechanistic exploration of glioma exosomes on peripheral myeloid tumor immunity.
TMIC-28. TARGETING TUMOR-ASSOCIATED SMOOTH MUSCLE ACTIN (ACTA2) EXPRESSION IN MOUSE PRE-CLINICAL GLIOMA MODELS REDUCES TUMOR PROGRESSION AND EXTENDS SURVIVAL
Authors: Comba Andrea , Varela Maria Luisa , Abel II Cliford , Faisal Syed , Castro Maria , Lowenstein Pedro 
Published: November 2023

Abstract
The ACTA2 gene, which encodes α-smooth-muscle actin, is known to be involved in contractility and oncogenic transformation. However, the specific role of tumor-associated ACTA2 mesenchymal cells in gliomas is unknown. Using genetically engineered mouse models (GEMM) of glioma, we discovered that ACTA2 expression was increased within oncostreams, which are malignant multicellular structures found in high-grade gliomas. Furthermore, we observed reduced expression of ACAT2 mRNA in IDH-Mut mouse gliomas vs WT tumors. Analyzing human glioma TCGA and CCGA databases revealed a negative correlation between tumor ACTA2 expression and overall survival in glioma patients. ACTA2 mRNA expression was also higher in grade IV and recurrent tumors. To investigate the role of ACTA2 in glioma cells, we created ACTA2 knockdown GEMM of glioma. These mice showed very large increases (~300%) in median survival (NPDS: 253 days, NPAS: 329 days) in comparison to their respective control groups (NPD: 89 days, NPA: 97 days). Glioma neurospheres derived from knockdown tumors confirmed downregulation of ACTA2, and showed reduced cell proliferation compared to controls. Moreover, orthotopic models revealed a decreased potential for tumor development in vivo. To explore the mechanism mediating the effects of ACTA2 downregulation, we conducted RNA-Seq analysis of ACTA2 knockdown neurospheres. This analysis identified approximately 5000 differentially expressed genes, with gene ontology analysis highlighting significant enrichment in biological processes such as cell adhesion, cell communication, and regulation of locomotion. Pathway analysis identified cytokine-receptor interactions, focal adhesion, and NFK-B signaling as the most significant signaling pathways affected by ACTA2 downregulation. Finally, we evaluated the release of cytokines into the cell-conditioned media and found significantly decreased levels of GSCF and GMSCF cytokines in ACTA2 knockdown compared to controls. These findings indicate that ACTA2 expression is a pro-tumoral gene involved in glioma progression and plays an essential role in altering the TME.
TMIC-38. MITOCHONDRIAL ATP BIOGENESIS REGULATED BY VDAC1 IN TMEM119+ TUMOR-ASSOCIATED MICROGLIA AND MACROPHAGES MEDIATES HIGH-GRADE GLIOMA GROWTH
Authors: Wu Caren , Chen Yiyun , Lin Ya-Jui , Wei Kuo-Chen , Chang Kwang-Yu , Feng Li-Ying , Wu An-Chih , Chen Ko-Ting , Ren Alexander Liang , Nitta Ryan , Wu Janet , Pant Ayush , Cho Kwang Bog , Mackall Crystal , Chuang Jian-Ying , Huang Chiung-Yin , Li Gordon , Jackson Christopher , Chen Pin-Yuan , Lim Michael 
Published: November 2023

Abstract
Patients with high-grade glioma have a poor prognosis and an average survival of less than 15 months, which is associated with an increase in tumor-associated microglia and macrophages (TAMs). TAMs in the glioma microenvironment are traditionally thought to suppress antitumor immune responses and are metabolically reprogrammed by glioma. However, it is unknown whether metabolic processes, like ATP synthesis, in TAMs can directly affect glioma growth. Through RNAseq, we identified a novel subpopulation that had elevated metabolic expression patterns. These TAMs (TMEM119+) had increased protein expression of ATP synthases and VDAC1, and surprisingly only TAMs located within the tumor center had increased mitochondrial energy potential. In vitro and ex vivo co-culture assays determined that activated TAMs increased the expression of metabolic, growth, and survival genes in high-grade glioma cells. These activated TAMs produced higher levels of extracellular ATP, which in turn increased glioma cell viability. Inhibition studies identified P2X purinoceptor 7 (P2X7R) as a key player in the TAMs ATP-induced glioma survival. Our findings demonstrate for the first time that a subpopulation of TAMs induced a more tumorigenic microenvironment through the secretion of ATP.
TMIC-52. HISTONE H3K27ME3 LEVEL GOVERN TUMOR-ASSOCIATED MICROGLIA REPROGRAMMING IN RESPONSE TO GBM
Authors: Kang Sangjo , Sattiraju Anirudh , Ughetta Mary , Tsankov Alexander , Friedel Roland , Zou Hongyan 
Published: November 2023

Abstract
Glioblastoma (GBM) is the most common malignant primary brain tumor and its invasive nature makes complete dissection difficult. However, how GBM invade in the brain is poorly understood. Although, microglia are the resident immune cells in the brain that can support GBM invasion, their roles are yet elusive. Here, we retraced early steps of GBM invasion and their interaction with tumor-associated microglia (TAM) in a highly infiltrative murine GBM model in immunocompetent background. We show that microglia are activated in a wide tumor field ahead of GBM invasion, followed by glial net formation, encircling invading tumors. Next, physical contacts with GBM cells initiate an astounding morphological, and functional transformation of microglia and marrow-derived macrophages to form collectively organized migration streams with intertwined GBM cells. Here we show that Kdm6b, a H3K27me3 demethylase, is induced in TAMs during this process. Intriguingly, GBM disseminated more widely in juvenile host brains, which was associated with highly induced Kdm6b expression. Moreover, we show that Kdm6b inhibition with small chemical inhibitor GSKJ-4, perturbs TAM reprogramming, and GBM invasion. Together, our data reveal that microglia reprogramming provide directional cues for GBM invasion through epigenetic mechanisms and this may give insights to halt GBM invasion.
TMIC-57. CHARTING THE SPATIAL ARCHITECTURE OF GLIOBLASTOMA USING GBMAP: INSIGHTS FROM IN SITU SEQUENCING
Authors: Ruiz Cristian , Marco-Salas Sergio , Samuelsson Erik , Grillo Marco , Brandner Sebastian , Roy Ananya , Forsberg-Nilsson Karin , Kranendonk Mariëtte , Nilsson Mats , Stunnenberg Hendrik 
Published: November 2023

Abstract
Glioblastoma (GB), an aggressive brain malignancy, is associated with poor prognosis and quality of life. Single-cell RNA sequencing has helped unravel the complexity of GB cell states. However, to comprehensively unravel the pathobiology of GB, it is essential to consider the spatial context in which these cells reside within the tumor microenvironment (TME). In this study, we aimed to understand the spatial architecture of GB tumors and its implications on cellular and molecular heterogeneity. To achieve this, we developed GBmap, a comprehensive resource that harmonizes 26 datasets comprising 239 patients and over 1.1 million cells. Leveraging computational advancements, we utilized GBmap to create a GB-specific panel for charting the spatial architecture of tumors using an in situ sequencing (ISS)-based platform (HybISS) in an independent cohort of 13 tumors. We curated a panel of 209 genes based on the GBmap, capturing cell phenotypic features, intra- and inter-tissue heterogeneity, and in silico L-R analysis predictions. The panel includes markers for specific cellular processes such as inflammation, extracellular matrix remodeling, hypoxia, and angiogenesis, providing an additional layer of functional information. Our optimized pipeline incorporates a new method for ISS-based transcriptomics data (direct RNA targeting), which enhances sensitivity and tolerance for tissue specimens of poorer RNA quality. This new approach enables improved cell type/state resolution and classification confidence. Using this advanced approach, we observed heterogeneous cell-cell colocalization patterns that vary among patients, revealing spatiotemporal distributions of specific cancer phenotypes and distinct co-localization patterns with neighboring cells in the TME. Our findings showcase the unprecedented spatial and cellular resolution achieved, surpassing previous GB studies. Our study sheds light on the spatial architecture of GB tumors, unveiling previously unexplored cellular and molecular interactions. GBmap and our optimized pipeline offer a powerful resource for researchers to investigate GB heterogeneity, generate hypotheses, and contribute to advancing GB research.
TMIC-68. SIRPΑ BLOCKADE AS AN IMMUNOTHERAPEUTIC STRATEGY TO TREAT BREAST CANCER BRAIN METASTASIS
Authors: Tsai Yu-Ting , Wilson Adam , Cook Katherine , Zhao Dawen , Lesser Glenn , Soto-Pantoja David R 
Published: November 2023

Abstract
Triple-negative breast cancer (TNBC) has a high incidence of brain metastasis, with no standard therapeutic strategy for treatment. Therefore, new targets are urgently needed to overcome disease mortality. The CD47/SIRPα signaling pathway is implicated in tumor progression due to bypassing innate and adaptive immune surveillance. Most strategies targeting this pathway focus on targeting the receptor CD47; however, direct targeting SIRPα as a potential approach to mitigate metastatic burden remains understudied. Single-cell-RNA-sequencing indicates that SIRPα expression on basal epithelial cells, and TCGA data shows SIRPα expression is associated with a significant reduction in survival in basal-like breast cancer. Our immune staining against SIRPα in breast cancer patient biopsies shows a 3.5-fold increase in expression in metastatic lesions compared to the primary tumor (n=19; p ≤ 0.01). Staining of 4T1 parental and brain-trophic 4T1-Br3 cells showed an 84% increase in SIRPα in the metastatic cells (n=3; p ≤ 0.05). Furthermore, Real-time cell impedance analysis revealed that SIRPα blockade inhibits TNBC 4T1br3 cell migration (n=4; p≤0.01), suggesting a link between SIRPα expression and metastatic potential. Furthermore, in vivo SIRPα blockade reduced brain metastatic burden by approximately 90%, (n=4-7; p ≤ 0.05). Digital spatial profiling of tissues revealed that SIRPα blockade was associated with reductions in immune checkpoints, including CTLA-4, PD-1, PD-L1, and LAG3, and immunosuppressive T-cell/monocyte populations. Furthermore, our spatial analysis indicated that brain lesions of WT mice have increases in the extracellular matrix protein fibronectin in the immune enriched regions, potentially serving as a barrier for immune cell infiltration contributing to invasion, metastasis, and immune evasion, was reduced by 70% in SIRPα treated brain lesions (n-3-6; p ≤ 0.05). Thus, these data suggest that SIRPα blockade may influence the tumor microenvironment to limit brain metastatic breast cancer growth and potentially enhance patient survival to metastatic brain disease.