bluuebunny/crossref_metadata_2025 huggingface dataset:
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

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< 0.01) and untreated controls (P= 0.01). This was confirmed via histology volumes; untreated group (P< 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< 0.06). A near statistically significant decrease in CD163 expression was observed at the tumor margin for Bac+CRT compared to CRT only (P< 0.06). Likewise when comparing CRT to untreated control (P< 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.
TMIC-76. PRMT5 MODULATES T CELL PROLIFERATION IN GLIOBLASTOMA TUMOR MICROENVIRONMENT
Authors: Walker Erin , Dowling Aimee , Jung Miyeon , Ertekin Celine , Brown Desmond , Banasavadi-Siddegowda Yeshavanth
Published: November 2024

INTRODUCTION

Glioblastoma, the most common malignant brain tumor, presents a significant obstacle because of its immunosuppressive tumor microenvironment, complicating standard treatment approaches. Protein Arginine Methyltransferase 5 (PRMT5) that regulates cellular functions by symmetrically dimethylating arginine residues is dysregulated in glioblastoma. Inhibiting PRMT5 induces apoptosis and senescence in the differentiated and undifferentiated glioblastoma tumor cells respectively. As PRMT5 is known to play an important role in immune cell response and T cell reprogramming, in this study we sought to probe the role of PRMT5 in the modulation of glioblastoma tumor immune response.

METHODS

We inhibited PRMT5 using small molecule inhibitor (LLY283) or PRMT5 target specific siRNA in patient-derived primary GBM neurospheres (GBMNS) and assessed the T-cell proliferation and MDSC induction by flow cytometry. Further, we also probed for PDL-1 and IL-6 expression by ELISA and westernblot assays. RESULT: PRMT5 inhibition significantly increased CD4+ T-cell proliferation but the MDSC induction was suppressed. As PDL-1/IL-6 axis is known to play a significant role in both anti-tumorigenic T-cell proliferation and pro-tumorigenic MDSC induction, we probed for the expression of PDL-1 and IL-6. While PRMT5 blockade reduced PDL-1 expression, IL-6 expression was upregulated.

CONCLUSION

Our results suggests that PRMT5 inhibition increases T-cell proliferation potentially by blocking MDSC induction. Further studies are underway to understand the nexus between PDL-1/IL-6 and modulation of MDSC/T-cell activation in the context of PRMT5 status in glioblastoma and their potential impact on the anti-tumorigenic effect in an in vivo GBM model.
TMIC-77. ELUCIDATING THE ROLE OF PTPRZ1 SIGNALING IN DRIVING GLIOBLASTOMA PROGRESSION USING THE NOVEL HUMAN ORGANOID TUMOR TRANSPLANTATION SYSTEM
Authors: Kan Ryan , Ge Weihong , Yilgor Can , Fazzari Elisa , Nano Patricia , Azizad Daria , Li Matthew , Ito Joyce , Tse Christopher , Tum Hong , Scholes Jessica , Patel Kunal , Nathanson David , Bhaduri Aparna
Published: November 2024

Glioblastoma (GBM), the most malignant and aggressive primary brain tumor, is driven by both intrinsic genetic mutations and extrinsic factors from the tumor microenvironment (TME). GBM manipulates the TME to enhance its survival and proliferation through mechanisms such as forming functional synapses with adjacent normal cells and secreting immunosuppressive factors. Our laboratory has developed a novel human organoid tumor transplantation (HOTT) model, which allows for the interrogation of tumor-normal cell crosstalk at a molecular level and facilitates the dissection of specific signaling pathways that drive tumor progression and maintenance. Using single-cell transcriptomics on human GBM HOTTs, we identified the PTN-PTPRZ1 ligand-receptor interaction as a critical mediator of tumor-microenvironment communication. PTPRZ1, a receptor tyrosine phosphatase, has been previously implicated in glioma cell migration, and our data further elucidate its role in modulating tumor behavior. Specifically, we demonstrated that knockdown of PTPRZ1 within the TME of human cortical organoids significantly enhances glioma cell migration and inhibits differentiation, underscoring the essential role of PTPRZ1 in maintaining the tumor’s invasive phenotype. Further pharmacological inhibition of PTPRZ1’s catalytic activity with a small molecule revealed that these effects on cell fate determination are independent of its phosphatase activity. This suggests that PTPRZ1 exerts critical non-catalytic functions that are pivotal for GBM progression. To further investigate these non-catalytic mechanisms, we propose utilizing single-cell transcriptomics coupled with proximity labeling and proteomics. This approach will allow us to comprehensively map PTPRZ1-mediated signaling networks and elucidate their impact on tumor biology, potentially unveiling novel therapeutic targets. Our findings revealed a novel axis of GBM biology mediated by PTPRZ1 and highlighted the importance of considering microenvironmental interactions in the development of effective therapeutics for GBM.
TMIC-78. CHEMOTHERAPY INDUCED IMMUNOGENIC RESPONSE IN GLIOMA AND IMPLICATIONS FOR THERAPEUTIC STRATEGIES
Authors: Teasley Damian , Dadario Nicholas , Lei Liang , Sperring Colin , Khoury Nadine , Rolfe Nathaniel , Kristt Melanie , Mela Angeliki , Ifedoria Nkechime , Kotidis Corina , Zhao Wenting , Furnari Julia , Mahajan Aayushi , Pereira Brianna , Argenziano Michael , Winans Nathan , Yoh Nina , Humala Nelson , Dovas Athanassios , Karan Charles , Gill Brian , Sims Peter , Bruce Jeffrey , Canoll Peter
Published: November 2024

INTRODUCTION

Many glioblastoma (GBM) treatments fail because they treat tumor cells in isolation and ignore the surrounding microenvironment. In our phase 1b clinical trial of delivery of Topotecan (TPT) via Convection Enhanced Delivery (CED) in glioma, we demonstrated effective tumor cell elimination accompanied by a robust inflammatory response. We hypothesized that TPT induces an immunogenic response resulting in an unfavorable inflammatory landscape.

METHODS

To characterize chemotherapy’s effect on myeloid cells, we analyzed pre- and post-treatment biopsies from our trial using bulk RNA sequencing to measure canonical myeloid markers. We validated survival benefit of CED in vivo in our tumor model and characterized post-treatment tissue using single cell RNA sequencing (scRNA seq) after 7 days of treatment. We treated slice cultures generated from surgical samples of GBM with TPT and performed scRNA seq and histologic analysis to assess microenvironment changes after 24 hours of treatment. We used several in vitro assays to characterize the direct and indirect mechanisms of myeloid activation.

RESULTS

Bulk RNA sequencing of post treatment biopsies demonstrates upregulation of markers associated with activated and exhausted immune cell populations such as IBA1, CD68, MSR1, MARCO and loss of markers associated with homeostatic microglia such as P2RY12 and TMEM119. Similar results are found within 7 days of treatment in vivo, however, are not found in human derived samples treated acutely. Treatment of in vitro mono and co-culture systems demonstrate a tumor cell death dependent activation of myeloid cell populations via immunogenic molecules.

CONCLUSIONS

Chemotherapies eliminate proliferating glioma cells but also induce inflammation. While many investigators have tried to leverage this activation, our results suggest that chronic inflammation contributes to poor prognosis and recurrence. The identification of molecules responsible for this activation point to new therapeutic targets aimed at controlling treatment-induced inflammation, as part of a combinatorial approach to treat GBM.
TMIC-80. HIGH-DIMENSIONAL HISTOPATHOLOGIC EVALUATION OF THE HYPOXIC TUMOR MICROENVIRONMENT IN GLIOBLASTOMA
Authors: Gandhi Shreya , Singh Olivia , Mansouri Sheila , Karimi Shirin , Lombard Phoebe , Dvorkin-Gheva Anna , Velasquez Carlos , Ali Hafsah , Devaraja Kaviya , Wei Qingxia , Wu Ronald , Li Mira , Cheung May , Voisin Mathew , Gao Andrew , Hedley David , Aldape Kenneth , Wouters Bradley , Zadeh Gelareh
Published: November 2024

Gliobastoma (GBM) is a highly aggressive solid tumor of the brain, characterized by a hypoxic tumor microevironment (TME) leading to histopathological features of necrosis, microvascular proliferation and deregulated hypervascularization. The heterogeneous nature of GBM results in a gradient of intra-tumoral hypoxia that causes molecular changes to specific cell populations within the bulk of the tumor. Our study is the first clinical study to utilize the exogenous oxygen-independent marker pimonidazole (PIMO) to identify the hypoxic TME using high-dimensional spatial and single-cell proteomics of specific cell populations within GBM. A cohort of 35 patients with primary GBM, recurrent GBM or IDH-mutant glioma were administered PIMO prior to surgical resection of tumor tissue for downstream bulk proteomic analysis of bulk tissue by serial immunohistochemistry and imaging mass cytometry (IMC) and single-cell analysis of dissociated tissue by Cytometry by time-of-flight (CyTOF). We utilized high-resolution imaging analyses to validate PIMO as a sensitive and stable marker for hypoxia against a panel of transiently expressed HIF-target genes and examine the inter- and intra-tumoral heterogeneity of hypoxia within each tumor subtype. A custom CyTOF marker panel was developed for further single-cell analyses of T-cell subsets and their functional states, myeloid cell subpopulations, natural killer cells, glial cells, and tumor cells in the hypoxic TME. We demonstrate the utility of PIMO to effectively study the hypoxic TME through spatial and single cell methods and further elucidate mechanisms of hypoxia-driven treatment resistance.
TMIC-86. THE ROLE AND THERAPEUTIC RESEARCH OF NETS IN PROMOTING TMZ RESISTANCE IN GLIOBLASTOMA
Authors: Zhao Shiguang
Published: November 2024

OBJECTIVE

This study aims to investigate the issue of resistance to temozolomide (TMZ) treatment in high-grade glioblastoma (GBM), specifically the association between TMZ resistance, the tumor microenvironment (TME), and neutrophil activity. The research hypothesis posits that changes in neutrophils induced by TMZ treatment, particularly the formation of neutrophil extracellular traps (NETs), may lead to TMZ resistance in GBM cells.

METHODS

The study utilized clinical data analysis and animal model research to evaluate changes in neutrophils during TMZ treatment and their impact on treatment efficacy. Proteomics analysis and high-throughput sequencing were employed to investigate the effect of TMZ on cytokine secretion by GBM cells and how these cytokines stimulate the release of NETs. Additionally, gene ontology (GO) analysis and bioinformatics methods were used to study how NETs promote the epithelial-mesenchymal transition (EMT) process and TMZ resistance by activating specific signaling pathways such as Jak-Stat3.

RESULTS

The study found that TMZ treatment led to increased neutrophil infiltration, which was associated with poor prognosis in GBM patients. TMZ treatment altered the levels of cytokines secreted by GBM cells, particularly IL-6, promoting the release of NETs by neutrophils. The formation of NETs was closely related to the activation of Stat3 signaling and the promotion of the EMT process in tumor cells, thereby enhancing TMZ resistance. Magnesium-based micromotors were found to improve TMZ efficacy by scavenging ROS production in neutrophils, inhibiting the release of NETs.

CONCLUSION

This study confirms the association between TMZ resistance and neutrophil activity, particularly the role of NETs in promoting EMT and resistance. These findings provide new insights into the treatment of GBM and offer a theoretical basis for the development of therapeutic strategies targeting NETs, which may improve the response of glioblastoma to TMZ treatment by inhibiting ROS production. The development of this novel therapeutic approach offers new treatment options for postoperative chemotherapy in GBM.
TMIC-87. ICAM-1 REGULATE EXTRACELLULAR VESICLE-MEDIATED IMMUNOSUPPRESSIVE MONOCYTE IN HUMAN GLIOBLASTOMA CELL
Authors: Jung Mi-Yeon , Oishi Masahiro , Walker Erin N , Barnes David , Nusraty Sabrina , Siddegowda Yesh Banasavadi , Parney Ian F , Brown Desmond A
Published: November 2024

Glioblastoma is the most common malignant primary brain tumor and is universally fatal. Treatment involves maximal safe resection with adjuvant chemoradiation. Poor prognosis in glioblastoma is multifactorial, and local and systemic immunosuppression is an important factor. Extracellular vesicles (EVs) are small, membrane-bound particles released by cells into the external environment. They play a key role in intercellular communication. In glioblastomas, EVs regulate immunosuppression through induction of myeloid-derived suppressor cells (MDSCs) in a process dependent on the PD-1/PD-L1 and IL-6 axes. Primary cilia are microtubule-based organelles that play crucial roles in various cellular processes and signal transduction cascades. We recently showed that primary cilia modulate IL-6 expression and consequently, MDSC induction. Comparative proteomic analysis of EVs derived from human glioblastoma cells devoid of cilia showed loss of ICAM-1 expression compared to control glioblastoma cells. ICAM-1 (Intercellular Adhesion Molecule-1) is a cell surface glycoprotein that mediates cell-cell adhesion and immune responses. In this study, we showed that depletion of primary cilia in human glioblastoma cells result in increased PD-L1 but loss of IL-6 and ICAM-1. RNAi-meidated loss of ICAM-1 was synergistic with primary cilia depletion in preventing MDSC inductionn normal human monocytes exposed to glioblastoma-derived EVs. Exogenous IFN-g was sufficient to restore IL-6 levels and MDSC induction despite loss of primary cilia and ICAM-1 suggesting that primary cilia act upstream of IFN-g, IL-6 and ICAM-1 in glioblastoma-mediated MDSC induction. This study is the first to connect primary cilia signal transduction to IL-6 and ICAM-1 expression and to MDSC induction. The evidence suggests a potential parallel primary cilia regulatory cascade independent of the PD-L1 axis that controls tumor-mediated immunosuppression. These results may inform novel therapeutic strategies aimed at increasing efficacy of immunotherapy in the glioblastoma and other neoplastic processes.
TMOD-12. DEFINING THE ROLE OF THE DAAM2 R414W GERMLINE VARIANT IN FAMILIAL GLIOMA
Authors: Choy Tiffany , Ye Qi , Deneen Benjamin , Bondy Melissa , Lee Hyun Kyoung
Published: November 2024

Malignant glioma is the most common primary brain tumor in adults, leading to high morbidity and mortality due to its aggressive nature and limited efficacious treatment options. To improve this prognosis, research has focused on genetic factors that may contribute to glioma. While most glioma cases arise from sporadic somatic mutations, approximately 5-10% are classified as familial glioma, stemming from inherited genetic variations. Although several studies have explored mechanisms behind somatic mutations in glioma, less is known about hereditary variants that promote glioma susceptibility. We recently discovered five germline mutations in Daam2 (Dishevelled associated activator of morphogenesis 2) from familial glioma patients. To examine the role of these mutations in familial glioma, we overexpressed these mutations in patient-derived glioma stem-like cells, which were subsequently orthotopically xenografted into immunodeficient mice. We identified that one of these mutations, Daam2-R414W, promotes tumor cell proliferation both in vitro and in vivo. To further understand the role of the Daam2-R414W mutation in familial glioma, we generated a knock-in immunocompetent mouse model with the Daam2-R414W mutation. In these mutant mice, we found an increased number of proliferating glial progenitor cells in the subventricular zone compared to Daam2 wildtype mice, suggesting the potential of the Daam2-R414W mutation to influence glial progenitor expansion to stimulate glioma initiation. Furthermore, to establish a potential mechanism, we performed proteomic profiling of Daam2 wildtype and Daam2-R414W overexpression tumors and found enrichment of Git1, a GTPase-activating protein involved in cytoskeletal remodeling, suggesting that the Daam2-R414W variant may interact with Git1 to promote tumor invasion. Our findings thus far identify a hereditary genetic variant with the potential to increase the risk of glioma, shedding light on the repercussions of a human developmental gene variant and its potential to disrupt normal cellular machinery to promote malignancy and glioma development.
TMOD-19. GERMLINEELP1 DEFICIENCY SENSITIZES CEREBELLAR GRANULE NEURON PROGENITORS TO SHH MEDULLOBLASTOMA
Authors: Tanveer Ahmad Shiekh , Garcia-Lopez Jesus , Li Yiran , Hadley Jennifer , Paul Leena , Gudenas Brian , Batts Melissa , Soliman Taha , Pitre Aaron , Kojic Marija , Manz Frederik , Zindy Frederique , Jones Alun , Mayasundari Anand , Bianski Brandon , Tinkle Christopher , Shirinifard Abbas , Janke Laura Janke , Lu Meifen , Onar-Thomas Arzu , Pfister Stefan , Gajjar Amar , Baker Suzanne , Roussel Martine , Rankovic Zoran , Robinson Giles , Orr Brent , Wainwright Brandon , Kutscher Lena , Waszak Sebastian , Lin Hong , Northcott Paul
Published: November 2024

Germline loss-of-function (LOF) variants in Elongator complex protein 1 (ELP1) are the most prevalent predisposing genetic events observed in medulloblastoma (MB), accounting for 30% of the Sonic Hedgehog 3 subtype (SHH-3). Molecularly, ELP1-associated SHH-MBs acquire somatic PTCH1 mutations in >80% of cases, and universal loss-of-heterozygosity of the wild-type ELP1 and PTCH1 alleles through loss of chromosome-arm 9q, resulting in their biallelic inactivation. Notably, germline ELP1 LOF occurs mutually exclusive with somatic/germline TP53 mutations in the SHH-3 subtype, suggesting that genetic perturbation of either ELP1 or TP53 may promote similar downstream oncogenic consequences in cerebellar granule neuron progenitors (GNPs), the accepted cellular origin of SHH-MB. Despite these findings, the molecular, biochemical, and cellular mechanism(s) by which ELP1-deficiency provokes malignant pathogenesis remain unknown. In this study, we sought to close this knowledge gap and functionally determine why children harboring pathogenic ELP1 germline variants are at an increased risk of developing SHH-MB. Mice were genetically engineered to mimic heterozygous Elp1 LOF (Elp1HET). We studied the effect of loss of ELP1 in GNPs using a combination of molecular profiling, immunophenotyping, and cellular assays. GNPs from Elp1HET exhibited a spectrum of molecular and biochemical hallmarks of malignant transformation including increased DNA replication stress, DNA damage, accelerated cell cycle progression, and stalled differentiation. Orthotopic transplantation of Elp1HET GNPs engineered to harbor somatic Ptch1 inactivation yielded SHH-MB-like tumors with compromised p53 signaling, providing an explanation for the specificity of ELP1-associated tumors in SHH-3, and their exclusivity with TP53-mutant tumors. Treatment of ELP1-mutant patient-derived xenografts with an FDA-approved MDM2 inhibitor reactivated p53-dependent apoptosis and extended survival. Collectively, our findings functionally substantiate the role of ELP1 deficiency in predisposition to SHH-3 MB and nominate therapeutic strategies to overcome p53 inhibition as a rational treatment option.
TMOD-20. RAPID PROCESSING AND BIOBANKING OF RESECTED BRAIN TUMOR TISSUE TO GENERATE PATIENT-DERIVED BRAIN TUMOR EXPLANT ORGANOIDS (GBOS) FOR PRECLINICAL STUDIES
Authors: Palethorpe Helen , Shard Chloe , Ryan Conor , Wenholz Daniel , Truong Quach , Scheer Kaitlin , Skarne Niclas , Patil Ashwini , Ormsby Rebecca , Poonnoose Santosh , Alexander Kimberley , Gan Hui , Day Bryan , Kumar Naresh , Wilkinson John , Gomez Guillermo
Published: November 2024

Improved preclinical tools are urgently needed to translate new brain cancer treatments. Patient-derived brain tumor explant organoids (GBOs) offer promise for studying tumor cells in a relevant human tumor microenvironment and predicting patient responses to therapy. However, generating GBOs is time-consuming, costly, and technically challenging, hindering the creation of comprehensive biobanks covering the spectrum of brain tumor heterogeneity. This work presents a semi-automated method for producing GBOs, involving tumor tissue processing, size selection, and same-day cryopreservation, reducing generation time to less than 1 hour. We established a biobank of 24 GBOs from 33 samples (11 males and 13 females) with primary (n=13, GBO Yield (GY)>90%) and recurrent (n=5, GY>90%) glioblastomas, high-grade gliomas (HGG, n=2, GY≤50%), and low-grade gliomas (LGG, n=2 with GY>90%, n=2 with GY≤50%). Using GBO size and propidium iodide as readouts, we used this biobank to compare anticancer activities of novel idronoxil-conjugated benzopyran compounds (NX786, NX904/904E1) against Bortezomib (100% cell death reference). NX786 and NX904/904E1 reduced GBO growth (≥50%) in all primary glioblastoma and one (of two) recurrent glioblastoma GBOs with milder effects in LGG GBOs. Two (of four) primary glioblastoma, one (of two) recurrent glioblastoma, and one LGG GBOs exhibited significant cell death (>60%) in response to NX904/904E1. In contrast, NX786 induced cell death in one (of three) primary glioblastoma (34% cell death) and one (of two) recurrent glioblastoma (71% cell death) GBOs but not in LGG GBOs, together showcasing varied responses across different brain tumors. Highly-passaged GBOs lacking the non-malignant tumor microenvironment were more susceptible to these treatments, underlining the tumor microenvironment’s critical role in responses to anticancer agents. We provide a new method for efficient processing and cryopreserving GBOs, enabling the establishment of large biobanks for patient-specific preclinical drug testing across brain tumor subgroups in a clinically relevant human 3D model.
TMOD-21. MOUSE MODEL TO CONDITIONALLY EXPRESS A DIFFUSE MIDLINE GLIOMA DERIVED MUTATION IN THE ONCOGENIC PHOSPHATASE PPM1D
Authors: Valentine Vennesa , Liu Harrison , Groth Abby , Maingi Spencer , Saravanapavan Avneesh , Tolliver Joshua , Williams Nerissa , Luo Lixia , Kirsch David , Reitman Zachary
Published: November 2024

Diffuse Midline Gliomas (DMGs) are incurable brain tumors of children and adults, and there is an urgent need for new therapeutic approaches. Their location within critical areas of the brain precludes complete surgical removal. While current treatment mainly relies on radiation therapy, its efficacy remains palliative. DMGs commonly harbor truncating mutations in the Mn2+/Mg2+-dependent protein phosphatase 1D (PPM1D), leading to a gain-of-function in PPM1D by enhancing protein stability and activity. Thus, investigating PPM1D protein expression and its regulatory mechanisms is crucial for understanding its oncogenic role and identifying therapeutic targets. To address this, we developed a Ppm1d-loxP-exon6-loxP-exon6-E518X-tag mouse allele (Ppm1d-FL). This allele allows conditional expression of DMG-derived truncating mutations from the endogenous Ppm1d locus when the loxP sites are recombined in the presence of Cre recombinase. Tosimulate primary gliomas, we utilized the RCAS/tv-a retrovirus system and Cre/loxP recombination platforms. Mouse pups were injected with RCAS retroviruses bearing oncogenic platelet-derived growth factor B, Cre recombinase, and luciferase reporter genes into the brainstem. We confirmed that Cre leads to expected recombination of Ppm1d-FL, leading to expression of DMG-derived truncated Ppm1d-E518X-Tag mRNA. We examined tumor-free survival data, which indicates accelerated tumor formation with Ppm1d-FL compared to littermate controls with wildtype Ppm1d. The tumors demonstrated expression of molecular biomarkers commonly found in DMGs. Single-cell RNA sequencing has identified pathways activated or inactivated upon Ppm1d mutation. These data shed light on the complex interplay between PPM1D mutations and glioma pathogenesis and may guide the design of therapies that target PPM1D molecular pathways.
TMOD-23. LENTIVIRAL-INDUCED BRAIN GLIOMAS IN RAT MODEL
Authors: Zhang Michelle , Lakhina Yuliya , Yonk Marybeth , Poth Kelly , Neill Stewart , Zhang Zhaobin , Assed Hemza , Tora Muhibullah , Donsante Anthony , Federici Thais , Lei Kecheng , Boulis Nicholas
Published: November 2024

High-grade gliomas are the most common type of malignant intracranial tumor with dismal five-year prognostic outcomes despite developments in chemoradiotherapy and surgical intervention. Distinct oncogenes associated with tumorigenesis and progression have been identified, providing targets for potential therapeutic interventions and modeling efforts. In this study, we evaluated the efficacy of vectors targeting EGFR and PTEN, individually and in combination to produce high-grade brain gliomas. Four groups of rats underwent intracranial stereotaxic injection of lentiviral vector into the forceps minor of the corpus callosum. All animals were weighed and monitored for behavioral deficits three times per week for 90 days. Upon signs of clinical morbidity or at 90 days post-inoculation, tissues were harvested and analyzed using hematoxylin and eosin and immunohistochemical staining. Rats injected with the combination of the EGFR and the sh-PTEN vectors exhibited declines in weight, survival, and motor function compared to the control. The combination of the EGFR and sh-PTEN vectors was the only condition to induce tumorigenesis with histopathological confirmation of high-grade identity as confirmed by immunohistochemistry showing the most positivity for GFAP and SOX2 compared to the control. Significant increases in Ki-67 characterized combination tumors as highly proliferative. Increased oxidative stress and angiogenesis were supported by significant increases in 4HNE, SMA, and HIF-1α in the tumors compared to other treatment groups. Thus, the present model of high-grade rat brain glioma provides a potential model to assess pathogenic pathways and evaluate therapeutic strategies.
TMOD-25. UTILIZING PRIMARY MACROPHAGES AS AN IMPROVED SERUM-FREE IN VITRO MODEL OF TUMOR-ASSOCIATED MACROPHAGES IN GLIOBLASTOMA
Authors: Alrefai Hasan , Elkholy Amr , Lin Benjamin , Kumar Manoj , Schanel Taylor , Nassour-Caswell Lauren , Anderson Joshua , Hicks Patricia , Ahn Erin , Miller C Ryan , Willey Christopher
Published: November 2024

BACKGROUND

Tumor-associated macrophages (TAMs) account for up to 40% of tumor mass in glioblastoma and over 70% of the immune cells contained therein. TAMs influence glioblastoma (GBM) growth, invasion, and resistance to therapy. Unfortunately, in vitro macrophage models typically employ immortalized cell lines, such as THP-1, which require serum for their growth and maintenance, and are often stimulated with IL-4/13 to mimic TAM function in vitro. Unfortunately, THP-1-derived macrophages do not readily adopt the M2 state and may be poor TAM models.

METHODS

The buffy coat from peripheral blood was isolated from healthy donor blood and plated in RPMI 1640 supplemented with 10% human serum and 50ng/mL of M-CSF. 25 ng/mL of M-CSF was added on day 3. The macrophages were washed, lifted, and plated in serum-free X VIVO-15 supplemented with M-CSF. Afterwards macrophages were left in an M0 (resting) state, or polarized towards an M1(pro-inflammatory) by stimulating with LPS/IFNγ, M2 (anti-inflammatory) by polarizing with IL-4/13, or TAM state by co-culturing with GBM patient-derived xenolines. Macrophage polarization was characterized through cytokine arrays, invasion, angiogenesis, and phagocytosis assays, comparing them to M0, M1, and M2 macrophages.

RESULTS

M1-polarized THP-1 macrophages displayed an increase in M1-associated markers, such as CD80 and HLA-DR (p<0.0001); however, M2-polarized THP-1 macrophages did not display an increase in the M2-associated surface marker, CD206 (p = 0.6167). Interestingly, M1-polarized peripheral blood mononuclear cell (PBMC)-derived macrophages displayed increases in the M1-associated markers, CD80 and CD369 (p< 0.01). Additionally, M2-polarized PBMC-derived macrophages displayed increases in CD206 (p<0.0001). Interestingly, TAMs derived from either THP-1s or PBMCs did not closely align with either polarization state using cell-surface markers, dPCR, or cytokine arrays.

CONCLUSIONS

We have demonstrated a serum-free method of generating a TAM model by polarizing primary macrophages towards a GBM-supportive phenotype that differs molecularly and functionally from M0, M1, and M2 macrophages.
TMOD-28. MODELING MICROENVIRONMENTAL DYNAMICS: A NOVEL 3D GLIOMA-NEURON FUSION MODEL
Authors: Oten Sena , Krishna Saritha , Picart Thiebaud , Daniel Andy , Gonzales Cesar Nava , Lu Katie
Published: November 2024

Gliomas engage in bidirectional interactions with their microenvironment, wherein neuronal activity influences glioma proliferation and gliomas induce neuronal hyperexcitability. Although various models elucidate this complex interplay, a preference for a three-dimensional (3D) cell culture model has emerged to mimic intra-tumoral heterogeneity and microenvironmental interactions influencing glioma invasion, resistance, and recurrence. This study introduces an in vitro, self-assembled, scaffold-free, neuron-glioma spheroid fusion model to investigate the electrophysiological and functional interplay between glioma and its microenvironment. Primary mouse cortical neurons (MCN) were isolated from prenatal brain tissues and were cultured at 500,000 cells/spheroid on ultra-low attachment plates. Glioma organoids (WHO Grade 2-4) were developed from primary patient-derived tissue samples and were allowed to self-assemble for at least two weeks. After spontaneous spiking activity was detected in MCN spheroids, they were combined with glioma organoids in culture and allowed to fuse. A multielectrode array (MEA) was used to characterize the electrophysiological properties of the fusion model. Structural and functional characterizations were performed using immunofluorescence staining of proliferation, microglial, astrocytic, synaptic, and tumor markers. Additionally, the electrophysiological effects of the dual-IDH-mutant inhibitor, Vorasidenib, were assessed in WHO grade 2-4 IDH-mutant gliomas. Electrophysiological analysis of glioma-neuron co-cultures using MEA demonstrated a significantly increased network synchrony and firing rate in the fusion model when compared with the neuron-only condition, consistent with 2D models in the past. In correlation, the fusion model also demonstrated a significant increase in the Ki67 proliferation index across WHO grade 2-4 gliomas when compared to the glioma organoid-only condition. Vorasidenib treatment decreased neuronal firing rate and synchrony. Together, these results offer a high-throughput 3D model for recapitulating the tumor-brain microenvironment for both low and high-grade gliomas. Future studies will focus on the use of this model for drug screening and the exploration of malignant transformation in gliomas.
TMOD-33. DOES PRE-CLINICAL DRUG ACTIVITY PREDICT PHASE II CLINICAL EFFICACY IN GLIOBLASTOMA? A DETAILED ANALYSIS
Authors: Zadeh Arman T , Crooks Elliot J , Volovetz Josephine , Sloan Anthony R , Lathia Justin D , Dhawan Andrew
Published: November 2024

Despite decades of research, there are fewer than six FDA-approved therapies for glioblastoma (GBM). The drug approval process relies on studies establishing pre-clinical activity, most commonly using murine models, followed by in human studies establishing safety and then efficacy. Although murine models for GBM have allowed for insights into tumor biology, their utility in assessing the efficacy of novel anti-cancer therapies remains highly debated. Here, we sought to establish whether there was any relationship between drug activity in preclinical models and phase 2 clinical trial outcomes. Using ClinicalTrials.gov (NIH), all phase 2 trials in glioblastoma up to December 2023 were queried and downloaded. Trials that were never started, had not yet started, were withdrawn, not completed, or contained indications beyond glioblastoma were excluded. Studies examining anti-tumor effects of an investigational agent with or without bevacizumab, temozolomide, or radiation therapy in glioblastoma were included, and studies examining alternative dosing strategies, various medical devices, or drug combinations, were excluded. The corresponding preclinical studies were identified via literature review for each clinical trial. Data including the progression free and overall survival benefit, mouse models used, and sample sizes were extracted from each study. 659 trials between 1994 and 2023 were included for analysis. Of these, 272 (41%) were for monotherapies, examining 90 unique small molecules. Preclinical endpoints included murine survival and tumor weight. In comparing mouse survival and tumor size to progression free and overall survival in humans, our preliminary analysis did not reveal any clear correlation. The correlation between preclinical and clinical drug response in GBM remains uncertain. Future work will examine whether mouse genotype, immune status, or GBM cell line used affected the degree of concordance with human clinical trial data. Our analysis suggests that further investigation into preclinical models of GBM, and standardized reporting of preclinical models, are needed.
TMOD-34. GENERATION OF BRAIN-VESSEL-GBM ASSEMBLOIDS USING PATIENT-DERIVED GLIOBLASTOMA TISSUE
Authors: ha Taehyeong , Hwang Kihwan , Nam Kyung Mi , Ji So Young , Kang Ho , Han Jung Ho , Kim Chae-Yong
Published: November 2024

Glioblastoma (GBM) is the most common malignant brain tumor of the central nervous system and has a significantly low survival rate of approximately 15 months. Current preclinical GBM models are limited by the lack of a normal human microenvironment and the inability of many tumor cell lines to accurately reproduce GBM biology. To address these limitations, we describe a detailed procedure to generate brain-vessel- GBM assembloids, which are fusions of glioblastoma organoids (GBOs) from resected patient tumor tissue and cerebral and vessel organoids derived from human pluripotent stem cells. The proposed methodology will be used to detect and treat brain tumors, which will enable personalized treatment for brain tumor diseases. By universalizing the methodology we present, we aim to encourage other scientists to further develop existing models for studying these lethal tumors.
TMOD-36. NANOGLIOS: A MINIATURIZED PATIENT AVATAR ENABLING RAPID AND HIGH-THROUGHPUT PHENOTYPIC SCREENING FOR GLIOMAS
Authors: Wang Zhaohui , Huang Wei , Kawakita Satoru , Bustamante Francisco , Larios Rene , Jiang Chongming , Lekovic Gregory P , Everson Richard G , Liau Linda M , Lai Albert , Wang Zhaohui
Published: November 2024

BACKGROUND

Establishing pre-clinical patient derived orthtopical xenograft models for IDH-mutant and H3K27M-mutant gliomas has presented significant histological challenges. There is increasing interest in developing faithful patient-derived ex vivo 3D models to replicate these type of gliomas, aiming to accelerate drug screening efforts.

METHOD

We developed a rapid approach for establishing nanoliter-sized miniature glioma organoids, termed NanoGlios, by leveraging emulsion microfluidics. We tested the robustness of NanoGlios for neurosphere culture, glioma xenografts, and primary patient samples, focusing on H3K27M-mutant diffuse midline gliomas (DMGs) and IDH-mutant gliomas. We compared the morphological features of NanoGlios to their counterparts using high-content imaging, H&E staining, and histological analysis. Additionally, we evaluated the mutation and gene expression profiles of NanoGlios relative to their counterparts. Furthermore, we conducted proof-of-concept drug screening of NanoGlios with various inhibitors and established an AI-enhanced high-throughput phenotypic imaging-based screening platform.

RESULTS

We successfully established NanoGlios from various sample sources, including neurospheres, xenografts, and primary tissues harboring H3K27M or IDH1/2 mutations. NanoGlios derived from xenografts or primary tissues captured more heterogeneous patterns as compared to the neuropsheres. We were able to generate thousands of NanoGlios and perform drug assays for hundreds of conditions at passage 0 within two weeks from both resected glioma tissues and xenografts. The AI phenotypic screening enabled us to identify differential responses of NanoGlios to ONC-201 treatment and drug responses to mutant IDH inhibitors Vorasidenib and Ivosidenib, which was not able to be detected by conventional cell viability bulk assays.
Radiation dose assessment during dental cone beam computed tomography procedures in Sri Lanka towards establishing a dose reference level
Authors: Nissanka Madumali , Satharasinghe Duminda , Jeyasugiththan Jeyasingam , Bandara Wikum , Wijayasinghe Wasundara , Weerapperuma Indika , Jayasuriya Nadeena , Jayasinghe Ruwan
Published: November 2024

This study assesses radiation doses in cone beam computed tomography (CBCT) procedures in Sri Lanka, with the goal of establishing initial diagnostic reference levels (DRLs). Data from 1162 retrospective scans across four institutions were analyzed, and the medians of the pooled dose distribution for seven clinical indication categories were presented as the DRL values. The proposed DRLs based on clinical indications are 1013 mGy·cm2 for pathological conditions including cysts, tumors, and lesions, 1307 mGy·cm2 for implant planning, 1266 mGy·cm2 for presurgery assessment, and 1585 mGy·cm2 for evaluation of sinus and nasal pathology, temporomandibular disorder, and facial trauma. Considerable variability in doses across facilities was observed, driven by differences in equipment and imaging practices. Therefore, this study recommends adopting suggested DRL values as benchmarks, standardizing protocols to reduce dose variability, and implementing a national framework for regular updates of DRL values.
Deciphering the accelerated expansion of China’s NEV sector post-2020: a cross-system analysis using multi-level perspective
Authors: Tsou Cheng-Ting , Kim Dong-Hyu
Published: November 2024

This article investigates the rapid expansion of China’s new energy vehicle market in the challenging context of global economic uncertainties and the pandemic, highlighting its significant growth since 2020. By delving deeper into the sectoral and geographical scope of the multi-level perspective concept, this study explores the interactions among various sociotechnical systems that have accelerated the development of China’s automotive electrification. The research offers a deep dive into the factors driving this sector’s growth using a mixed-methods approach, including participatory observation, expert interviews, and secondary data analysis. The findings provide a detailed examination of the NEV market’s evolution and offer a methodological blueprint for analysing the intricate progression of automotive electrification in China, serving as a resource for policymakers and industry stakeholders. This work enhances the discourse on sociotechnical transitions, equipping decision makers with critical insights for steering the industry’s future direction.
Perioperative pain management for cardiac surgery
Authors: Yakubi Masseh , Curtis Sam , Anwar Sibtain
Published: November 2024

Purpose of review

Acute postsurgical pain after cardiac surgery is challenging to treat. Adverse effects related to the high dose opioids which have traditionally been used perioperatively in cardiac surgery have led to the adoption of alternative analgesic strategies. This review aims to highlight current evidence-based approaches to managing pain after cardiac surgery

Recent findings

Current evidence and international guidelines support the use of multimodal analgesics for managing perioperative pain after cardiac surgery. Regional anaesthesia in the form of fascial plane blocks, such as the erector spinae plane and parasternal intercostal plane blocks, are effective and safe techniques for anticoagulated cardiac surgery patients. Transitional pain services are multidisciplinary programmes that bridge the gap between inpatient and outpatient care for these patients.

This paper reviews advancements in perioperative pain management for cardiac surgery patients, emphasising the shift from high-dose opioids to multimodal analgesia and regional anaesthetic techniques, and highlighting the role of multidisciplinary transitional pain services.
Perioperative risk scores: prediction, pitfalls, and progress
Authors: Bedford Jonathan P. , Redfern Oliver C. , O’Brien Benjamin , Watkinson Peter J.
Published: November 2024

Purpose of review

Perioperative risk scores aim to risk-stratify patients to guide their evaluation and management. Several scores are established in clinical practice, but often do not generalize well to new data and require ongoing updates to improve their reliability. Recent advances in machine learning have the potential to handle multidimensional data and associated interactions, however their clinical utility has yet to be consistently demonstrated. In this review, we introduce key model performance metrics, highlight pitfalls in model development, and examine current perioperative risk scores, their limitations, and future directions in risk modelling.

Recent findings

Newer perioperative risk scores developed in larger cohorts appear to outperform older tools. Recent updates have further improved their performance. Machine learning techniques show promise in leveraging multidimensional data, but integrating these complex tools into clinical practice requires further validation, and a focus on implementation principles to ensure these tools are trusted and usable.

All perioperative risk scores have some limitations, highlighting the need for robust model development and validation. Advancements in machine learning present promising opportunities to enhance this field, particularly through the integration of diverse data sources that may improve predictive performance. Future work should focus on improving model interpretability and incorporating continuous learning mechanisms to increase their clinical utility.
Neurodevelopmental Outcomes after Multiple General Anesthetic Exposures before 5 Years of Age: A Cohort Study
Authors: Xin Annie , Grobler Anneke , Bell Graham , de Graaff Jurgen C. , Dorris Liam , Disma Nicola , McCann Mary Ellen , Withington Davinia E. , Davidson Andrew J.
Published: November 2024

Background:

The general anaesthesia or awake-regional anaesthesia in infancy (GAS) trial demonstrated evidence that most neurodevelopmental outcomes at 2 and 5 yr of age in infants who received a single general anesthetic for elective inguinal herniorrhaphy were clinically equivalent when compared to infants who did not receive general anesthesia. More than 20% of the children in the trial had at least one subsequent anesthetic exposure after their initial surgery. Using the GAS database, this study aimed to address whether multiple (two or more) general anesthetic exposures compared to one or no general anesthetic exposure in early childhood were associated with worse neurodevelopmental outcomes at 5 yr.

Methods:

Children with multiple general anesthetic exposures and children with one or no general anesthetic exposure were identified from the GAS database. The primary outcome was the full-scale intelligence quotient on the Wechsler Preschool and Primary Scale of Intelligence (third edition) at 5 yr of age. Secondary outcomes included neurocognitive tests addressing all major developmental domains and caregiver-reported questionnaires assessing emotional and behavioral problems.

Results:

Complete assessment was available from a total of 90 children in the multiple general anesthetic group and 141 children in the no or one general anesthetic group. Compared with children with a single or no general anesthetic exposure, multiply exposed children scored on average almost 6 points lower (mean, −5.8; 95% CI, −10.2 to −1.4; P = 0.011) in the Wechsler Preschool and Primary Scale of Intelligence full-scale intelligence quotient. They also demonstrated lower verbal and performance IQ scores and more emotional, behavioral, and executive function difficulties. However, significant residual confounding cannot be excluded from the results due to the observational nature of this study.

Conclusions:

Multiple general anesthetic exposures before 5 yr of age were associated with reduced performance in general intelligence score and some domains of neurodevelopmental assessments. The clinical significance of this study’s results must be cautiously interpreted in light of several sources of limitations including small sample size and unadjusted residual confounding. This study illustrates the limitations of trial data sets that may not be fit for the purpose for the secondary analysis.