bluuebunny/crossref_metadata_2025_split huggingface dataset:
EXTH-11. ADOPTIVE CELLULAR THERAPY OVERCOMES GLIOMA IMMUNE ESCAPE BY DISRUPTING MDSC PROLIFERATION AND RECRUITMENT
Authors: Figg John , Francis Connor , Jin Dan , Dean Bayli DiVita , Font Laura Falceto , Reid Alexandra , McDonald Brianna , Hilferty David , Long-James Kaytora , Flores Catherine 
Published: November 2023

Abstract

INTRODUCTION
Our group has previously shown that adoptive cellular therapy (ACT) significantly extends survival in models of medulloblastoma, brain stem glioma, and glioblastoma. Further, ACT significantly decreases myeloid-derived suppressor cells (MDSC) in the tumor microenvironment (TME), suggesting that ACT may ameliorate glioma-mediated immunosuppression. We hypothesize that ACT-mediated reduction of MDSCs is driven by cell proliferation and recruitment mechanisms, but these mechanisms have not been defined. In this study, we quantified the proportions and cell cycle states of MDSCs in the TME and peripheral lymphoid tissues as well as chemokines in serum to determine how ACT affects MDSC recruitment.

METHODS
ACT was performed in C57BL/6J mice bearing a syngeneic high-grade glioma derived from KR158B-luciferase cell line. The treatment platform included total body irradiation, hematopoietic stem cell rescue, total tumor ribonucleic acid (ttRNA) electroporated dendritic cells, and tumor-reactive T cells. Following ACT completion, we evaluated the proportions and cell cycle states of MDSCs using flow cytometry. Bromodeoxyuridine (BRDU) and 7-aminoactinomycin (7-AAD) defined cell cycle phases. Serum chemokines were measured using a membrane-based sandwich immunoassay.

RESULTS
We replicated our previous findings that ACT reduces the level of MDSCs in the TME. Additionally, ACT significantly decreased the proportion of MDSCs in S-phase in the TME. Conversely, levels of MDSCs in peripheral lymphoid tissue were significantly increased in mice treated with ACT, with a significant increase of MDSCs in S-phase. Analysis of serum chemokines revealed significant decreases in multiple chemokines implicated in MDSC recruitment such as CXCL13 and CXCL16.

CONCLUSION
These findings suggest that ACT decreases proliferation and chemotactic recruitment of MDSCs to the TME, which may also explain MDSC accumulation peripheral lymphoid tissue in ACT-treated mice. These immune mechanisms likely contribute to ACT’s efficacy against brain cancer, preventing tumor immune escape, and offer new therapeutic targets for optimizing cellular immunotherapies.
EXTH-12. CYTOCHROME C OXIDASE SUBUNIT 4 ISOFORM 1 MEDIATES ONCOLYTIC HERPES SIMPLEX VIRUS-1 EFFICACY IN HIGH-GRADE GLIOMA
Authors: Gary Sam , Laufer Vincent , Tuy Kaysaw , Kang Kyung-Don , Oliva Claudia , Griguer Corinne , Hjelmeland Anita , Friedman Gregory 
Published: November 2023

Abstract

RATIONALE
Outcomes for patients with high-grade glioma (HGG) are dismal despite standard of care surgical resection, radiation, and temozolomide (TMZ) chemotherapy.

RESULTS
from our Phase I trial of pediatric patients with recurrent HGG suggest oncolytic herpes simplex virus-1 (oHSV) is safe with promising efficacy. However, optimization of oHSV therapy is needed to achieve more durable responses. Based on our prior work with matched pair HGG cell lines and patient-derived xenografts (PDXs) with and without acquired TMZ resistance, oHSV efficacy is enhanced in TMZ-resistant cells with no difference in oHSV entry receptor (CD111) expression. Microarray transcriptomic data of four PDXs with and without TMZ resistance revealed downregulation of interferon (IFN) responses. Cytochrome c oxidase subunit 4 isoform 1 (COX4I1) is expressed in recurrent HGG samples and cell lines. While COX4I1 positively regulates influenza virus replication, no study has investigated the role of COX4I1 in mediating oncolytic virotherapy efficacy.

HYPOTHESIS
We hypothesized that COX4I1 expression mediates HGG sensitivity to oHSV through suppression of IFN signaling.

METHODS
Using previously published models, oHSV cytotoxicity was assessed in vitro using Alamar Blue and CellTiter-Glo assays. oHSV infectivity and CD111 protein expression was assessed by flow cytometry. COX4I1 protein expression was measured by immunoblot. mRNA expression of IFN-stimulated genes was assessed by qPCR.

RESULTS
COX4I1 overexpression increased oHSV cytotoxicity and infectivity compared to empty vector controls. Short hairpin RNA knockdown of COX4I1 decreased oHSV cytotoxicity and infectivity in TMZ-resistant cells compared to pLKO controls. IFN-stimulated genes IFNB1, TMEM173, DDX58, IFIH1, and OAS1 were all significantly decreased in COX4I1 overexpressing cells and TMZ-resistant cells compared to parental lines.

CONCLUSIONS
Overexpression of COX4I1 sensitizes HGG cells to oHSV, and COX4I1 knockdown de-sensitizes TMZ-resistant HGG cells to oHSV, suggesting a novel role of COX4I1 in mediating HGG sensitivity to oHSV.
EXTH-15. A NOVEL IMMUNE-BASED TREATMENT STRATEGY FOR COMBATTING PROTEIN TUMOR HETEROGENEITY
Authors: Wilkinson Daniel , Srinivasan Ethan , Lerner Emily , Fecci Peter 
Published: November 2023

Abstract
Cell-based immunotherapy has revolutionized the treatment of many hematological malignancies but has mostly fail against solid tumors, including glioblastoma (GBM). The reason for this failure is multi-fold, but one of the most significant barriers is the extensive intratumoral heterogeneity that characterizes these tumors. Unfortunately, this problem has not been eliminated by personalized medicine strategies aimed at sequencing individual tumors and targeting the uncovered neoantigens. Thinking “outside the box” led us to examine other types of tumor-specific alterations that might more ubiquitously characterize tumor cells, while still being targetable by an immune-based platform. Our investigations led us to the phospholipid phosphatidylserine (PS). PS is typically present on the cytoplasm-facing side of the plasma membrane, where it remains out of view to the immune system. Cellular stresses can lead to dysregulation of processes that keep PS facing internally and instead promote PS exposure on the cell surface. We show here that tumor cells frequently lose the capacity to regulate their plasma membrane and exhibit detectable levels of PS on their surface. Moreover, inducing cell stress through radiation and chemotherapy of tumor cells further enhanced PS exposure. In this study, we aimed to target PS with an immune-based therapy. To this end, we engineered a bi-specific T cell engager (BiTE) consisting of the natural high-affinity PS receptor TIM4 linked to an anti-CD3scFv. This TIM4 BiTE is hypothesized to redirect all T cells to PS, resulting in T cell-mediated killing of tumor cells with exposed PS. Indeed, TIM4 BiTE facilitated potent killing of multiple human tumor cell lines in vitro, including in models of protein heterogeneous tumors. When TIM4 BiTE was delivered intratumorally to a heterogeneous glioma-bearing mouse, survival was significantly extended. These data provide evidence that targeting PS with an immune-based platform represents a potential novel treatment strategy for combatting tumor heterogeneity.
EXTH-16. DEVELOPMENT OF INTRATHECAL (IT) DRUG DELIVERY PLATFORM TO CURE BREAST CANCER (BC) LEPTOMENINGEAL DISEASE (LMD) BY PEPTIDE-PULSED TYPE 1 CONVENTIONAL DENDRITIC CELL (CDC1) VACCINE IN PRECLINICAL MODEL
Authors: Law Vincent , Snyder Colin , Macaisa Lauren , Garg Saurabh , Czerniecki Brian , Forsyth Peter 
Published: November 2023

Abstract

BACKGROUND
LMD is a rare form of metastasis in the meninges. Approximately 5% of advanced stage BC will develop LMD and currently there is no cure. One of the major hurdles is drug penetration due to the blood brain barrier (BBB) and blood-cerebral spinal fluid (CSF)-barrier. While the Ommaya reservoir is used clinically to overcome this challenge, there has not been an optimized preclinical model that allows researchers to adequately test novel therapies in the CSF space.

METHODS
The Forsyth lab have recently developed an MRI-compatible device called the “murine Ommaya” which mimics the Ommaya reservoir and allows repeated IT administration of drugs in minute 3-7 μL directly into CSF, bypassing BBB. In a joint effort with Dr. Czerniecki, whose lab have developed a pipeline for screening immunogenic MHC class II peptides from tumor-associated oncodrivers and subsequently generating tumor-targeting cDC1s, we have created a platform to IT deliver peptide-pulsed cDC1 immunotherapy directly targeting BC-LMD.

RESULTS
Currently, we have tested the efficacy of treatment in HER2+ LMD and triple negative breast cancer (TNBC) LMD models and found a very favorable response; LMD mice that received IT cDC1 therapy showed tumor regression and their survival were significantly prolonged. About 70% of mice from HER2+ LMD and 30% from TNBC LMD were eventually disease-free. Cured mice also exhibited resistance against LMD recurrence.

CONCLUSIONS
Our preliminary data suggest IT cDC1 vaccine is effective against the incurable BC-LMD. We are currently investigating the mechanism(s) by which IT cDC1-initiated CD4 Th1 adaptive immune response against LMD. By using single-cell RNA-sequencing technique, we are analyzing the immune landscape in CSF tumor microenvironment in response to IT cDC1. FDA-approved phase 1 clinical trial has been funded by the DOD. Future approach includes employing our IT cDC1 immunotherapy platform in other cancer types, such as LMD from melanoma.
EXTH-21. FKBP38 REGULATES SELF-RENEWAL AND SURVIVAL OF GBM NEUROSPHERES
Authors: Dowling Aimee , Walbridge Stuart , Ertekin Celine , Bryant Jean-Paul , Kohut Eric , Chowdhury Ashis , Brown Desmond , Heiss John , Banasavadi-Siddegowda Yeshavanth Kumar 
Published: November 2023

Abstract
Glioblastoma (GBM) is the most common malignant primary brain tumor. The outcome is dismal, despite the multimodal therapeutic approach that includes surgical resection followed by radiation and chemotherapy. The quest for novel therapeutic targets to treat GBM is underway. FKBP38, a member of the immunophilin family of proteins, is a multidomain protein that plays an important role in the regulation of cellular functions including apoptosis and autophagy. In this study, we tested the role of FKBP38 in GBM tumor biology. Expression of FKBP38 is upregulated in the patient-derived primary GBM neurospheres (GBMNS) compared to normal human astrocytes. Attenuation of FKBP38 expression decreased the viability of GBMNS and increased the caspase 3/7 activity indicating that FKBP38 is required for the survival of GBMNS. Further, the depletion of FKBP38 significantly reduced the number of neurospheres that were formed implying that FKBP38 regulates the self-renewal of GBMNS. Also, the transient knockdown of FKBP38 increased the LC3-II/I ratio suggesting the induction of autophagy with the depletion of FKBP38. Further investigation showed that the negative regulation of autophagy by FKBP38 in GBMNS is mediated through the JNK/C-Jun-PTEN-AKT pathway. In vivo, FKBP38 depletion significantly extended the survival of tumor-bearing mice. Overall, our results suggest targeting FKBP38 imparts an anti-GBM effect by inducing apoptosis and autophagy and thus can be a potential therapeutic target for GBM therapy.
EXTH-22. AN IND-ENABLED STUDY USING A NOVEL CHECKPOINT BLOCKADE OF LAIR1 FOR GLIOBLASTOMA THERAPY
Authors: Tao Haipeng , Chen Dongjiang , Yang Changlin , Nguyen Duy , Pepe Alfonso , Pedro Diego , Jin Linchun , Liu Ruixuan , Liu Tianyi , Von Roemeling Christina , Abbas Muhammad , Hou Alicia Y , Petit Nicole , Abboud Georges , Mendez-Gomez Hector , Weidert Frances , Jin Dan , Long-James Kaytora , Sayour Elias , Deleyrolle Loic , Gregory Sawyer W , Mitchell Duane , Huang Jianping 
Published: November 2023

Abstract

BACKGROUND
Our research study focuses on the recently discovered immune checkpoint known as Leukocyte-Associated Immunoglobulin-like Receptor 1 (LAIR1), which is found to be overexpressed on tumor-associated myeloid cells (MAMC), including Tumor-associated macrophages (TAM) and Myeloid-derived suppressive cells (MDSC), in GBM and other solid cancers. The overexpression of LAIR1 in gliomas is associated with poor survival, which has prompted investigations into the potential of LAIR1 blockade (aLAIR1) as a therapeutic strategy. In preclinical mouse models, Objective: A) To investigate the mechanism of LAIR1, a new class of immune checkpoint. B) To develop strategies for blocking LAIR1 signaling as a means of cancer therapeutics, thereby enabling novel mono and combinatorial treatments for GBM.

METHODS
1) Conduct coculture experiments using human TAMs and autologous CAR T cells in a 3D microgel bio-printing system, which allows us to recreate TME using patient-derived immune cells and a heterogeneous glioma model. By monitoring this coculture system, we aim to gain insights into the inhibitory effects of TAMs on T cells mediated by LAIR1. 2) Utilize tumor-burden wild-type and LAIR1 knockout mice to compare the intratumoral immune cell infiltration between WT and KO mice. 3) Employ sc-RNA-seq to identify key molecules involved in the TAM-T cell interaction. 4) Perform pathway analysis to identify signaling pathways that are influenced by this interaction.

RESULTS
aLAIR1 shifted macrophage polarization from M1 to M2 and increased memory CD8+ T cells intratumorally. It reversed MDSC- or M2- macrophage-mediated T-cell suppression, resulting in enhanced antitumor response as a standalone treatment and when used in combination with CAR T cell therapy in PD-1-resistant tumor models.

CONCLUSIONS
LAIR1 is a newly identified innate immune checkpoint that is highly expressed on TAMC in solid tumors, contributing to tumor progression and drug resistance. Blocking the LAIR1 signaling pathway shows promise as an effective approach for cancer therapy.
EXTH-27. ASSESING THE EFFECT OF ELECTRIC FIELD THERAPY ON PATIENT DERIVED GLIOMA STEM CELL LINES AND GLIOMA INFILTRATING CEREBRAL ORGANOIDS
Authors: Narayanan Ashwin , Zhao Jinwei , Olukoga Tomisin , Bullock Christopher , Fu Richard 
Published: November 2023

Abstract
Glioblastoma (GBM) is the most aggressive primary brain tumour in adults. Electric field therapy (EFT) is a new cancer treatment applied after safe maximal tumour resection that interferes with cancer cell division, slowing tumour recurrence and prolonging life. In GBM patients, this therapeutic modality has demonstrated an increase in median survival from ~16 to ~21 months. This study aimed to assess and decipher the effectiveness of EFT on patient-derived glioblastoma stem cell lines (GSC) as well as on advanced Glioma infiltrating cerebral organoid models (GLICOs). To achieve the project goals, we used a novel In-vitro EFT stimulation apparatus to test stimulation parameters on multiple patient-derived GSC lines as well as GLICO models derived from them. We used advanced microscopy and transcriptomic sequencing to visualize and decipher the causal effect of our stimulation regime on the in-vitro models. We observe a strong effect of our EFT regime on multiple GSC lines as well as on GLICOs when compared to their controls. Transcriptomic analysis showed multitude of differentially expressed mRNAs between the treated and control samples with multiple pathways being dysregulated from nuclear proteins, cell mitosis-related events and activation of non-apoptotic mediated programmed cell death pathways indicating a novel mechanism of action. Advanced causal inference studies using the data also provided novel insights on combinatorial therapies that could enhance the efficacy of the treatment. This study provides novel understanding of the mechanism of EFT with potential for optimised treatment regimens for GBM patients.
EXTH-30. GOLD NANOSTARS OBVIATE LIMITATIONS TO LASER INTERSTITIAL THERMAL THERAPY (LITT) AND ENHANCE THE POST-LITT IMMUNE RESPONSE
Authors: Srinivasan Ethan , Liu Yang , Odion Ren , Chongsathidkiet Pakawat , Wachsmuth Lucas , Haskell-Mendoza Aden , Edwards Ryan , Canning Aidan , Willoughby Gavin , Hinton Joseph , Norton Stephen , Lascola Christopher , Maccarini Paolo , Mariani Christopher , Vo-Dinh Tuan , Fecci Peter 
Published: November 2023

Abstract
Laser interstitial thermal therapy (LITT) is a minimally-invasive technique for the treatment of intracranial tumors that uses a stereotactically-guided laser and real-time magnetic resonance imaging (MRI) to monitor ablation progress. Previous applications of gold nanostars (GNS) in laser ablation of tumors have studied extracranial tumors only and utilized externally administered near infrared radiation that cannot penetrate the cranial compartment. Herein, we present a novel platform for employing GNS in intracranial tumors. We developed non-toxic GNS that exhibit maximum photothermal effects at the 1064 nm laser wavelength used in the FDA-approved clinical Neuroblate® LITT system. Monte Carlo simulations demonstrate that our GNS can accelerate and focus thermal energy distributions. Using ex vivo tumor phantom models, we found that GNS-infused phantoms demonstrate more rapid heating and improved spatial conformation of thermal energy, with neighboring material exposed to lower temperatures than controls. In our intracranial CT-2A glioma model, we quantified accumulation of radiolabeled GNS in tumor tissue via PET/CT. As further validation of tumor-selective GNS accumulation, we used two-photon luminescence to show that GNS selectively accumulate and are retained in intracranial tumors at 24 and 72 hours post-injection. We then utilized our in vivo heterotopic CT-2A model to assess the capacity of systemically-delivered GNS to augment laser ablation; we were able to achieve higher ablation temperatures and more efficient temperature ramping with LITT+GNS. Finally, we explored the potential of LITT+GNS to synergize with immunotherapy to further enhance the post-ablation immune response and found that combination therapy resulted in improved tumor control and immunologic memory that was protective against tumor rechallenge. These results support the ability of GNS to optimize LITT for the treatment of intracranial tumors by improving efficiency and safety, and illustrate the potential of this platform to synergize with immunotherapy.
EXTH-33. RAGE INHIBITOR (TTP488) AS AN ALTERNATIVE TO DEXAMETHASONE FOR MANAGING CEREBRAL EDEMA FOLLOWING BRAIN TUMOR SURGERY
Authors: Dayyani Mojtaba , Filippov Aleksandr , Zhang Ian , Georges Joseph , Saeed Zaan , Turunen Jillyn , Zhang Larry , Maus Rachel , Portnow Jana , Badie Behnam 
Published: November 2023

Abstract

BACKGROUND
Cerebral edema (CE) commonly occurs after neurosurgical procedures and contributes to patient morbidity and neurological deterioration. Corticosteroids alleviate brain edema during the perioperative period, but they impose several undesirable side effects and interfere with immunotherapies in patients with malignant brain tumors.

OBJECTIVE
To assess the anti-inflammatory effects of TTP488 (inhibitor of receptor for advanced glycation end products) on CE formation following tumor resection in glioma models.

METHODS
Mice harboring orthotopic CT-2A gliomas were randomly assigned to three groups and underwent tumor resection. TTP488, dexamethasone, and vehicle were administered perioperatively (day -4 pre-op to day 7 post-op) and post-operative neurological function was examined. CE was assessed on serial brain MRIs over a 7-day period, and using manual segmentation techniques, tumor-related volumes were calculated. In a separate survival experiment, the effect of each drug on anti-PD-1 immunotherapy response was measured.

RESULTS
In each group, CE peaked on post-operative day 2 and gradually diminished by day 7. On post-operative day one, mice treated with TTP488 showed a marked reduction in CE compared to those treated with either dexamethasone or vehicle with mean CE volumes of 1.75±1.08%, 2.69±0.77%, and 3.87±1.07%, respectively (P=0.02, TTP488 vs vehicle). Furthermore, the TTP488 group had better functional recovery scores (P=0.04) and wound healing (dehiscence, P=0.00003) compared to the vehicle group. Interestingly, unlike dexamethasone, TTP488 did not abrogate the efficacy of immunotherapy in the CT-2A glioma model.

CONCLUSION
TTP488 was as effective as dexamethasone in alleviating CE caused by tumor resection and did not interfere with the efficacy of immunotherapy. TTP488 could potentially be an alternative to dexamethasone in the perioperative management of patients undergoing tumor resection or other neurosurgical interventions.
EXTH-34. LOCAL DELIVERY OF AN IL-15 SUPERAGONIST USING A REPLICATING RETROVIRUS SYNGERIZES WITH TEMOZOLOMIDE TO INCREASE LYMPHOCYTE INFILTRATION AND SURVIVAL IN TWO POORLY IMMUNOGENIC GLIOBLASTOMA MOUSE MODELS
Authors: Haddad Alexander F , Spatz Jordan , Saha Atul , Montoya Megan , Collins Sara , Gill Sabraj , Wang Elaina , Chuntova Pavlina , Salha Diana , Young Jacob , Kasahara Noriyuki , Aghi Manish 
Published: November 2023

Abstract
Glioblastoma (GBM) leads to systemic and local immunosuppression and immunotherapies have had limited clinical success. We evaluated the treatment efficacy of RLI (receptor-linker-IL-15), a superagonist of T-cell activator IL-15, delivered to tumor cells using a tumor-selective retroviral replicating vector (RRV) in the syngeneic murine SB28 and Tu2449 GBM models, which are poorly immunogenic with low-mutational burden and known resistance to immunotherapy, similar to human GBM. RRV-RLI replicated and spread in cultured SB28 murine GBM cells with robust production of functional RLI (165.4 ± 5.3 ng/mL). Stereotactic injection of RRV-RLI into pre-established intracerebral Tu2449 tumors led to complete eradication of intracerebral tumors with long term survival (median not reached) in &gt; 85% of treated mice vs. median survival of 12.5 days in control mice (p=0.001). Treated mice demonstrated significantly increased CD8 T cell infiltration. These mice also demonstrated immunologic memory to intracranial rechallenge. In SB28, RRV-RLI delivery into intracerebral tumors reduced tumor growth on bioluminescence imaging, and increased median survival compared to controls (55 vs. 19 days, p=0.002), with long-term survival in 12% of treated mice. Combining RRV-RLI treatment with systemically administered temozolomide (TMZ) in the SB28 model provided long term survival (median not reached) in &gt;60% of treated mice. Immunologic analysis of treated tumors revealed a significant increase in CD8 T cell (2.1% to 20.5% of CD45 cells) and Natural Killer cell (1.4% to 9.6% of CD45 cells )infiltration in RLI-RRV+TMZ mice vs. PBS+TMZ mice. RLI was not detected in the blood of treated mice, and tumor-localized RRV-RLI gene delivery showed no adverse systemic immune effects. In summary, RRV-mediated RLI immunotherapy results in immunostimulatory changes that are further potentiated by systemically administered temozolomide. This tumor-localized gene therapy has the potential to synergize with standard of care treatment to reverse the immunosuppressed GBM tumor microenvironment and provide a significant treatment benefit.