tbuckley/cabot-search huggingface dataset:
EXTH-52. SIMULTANEOUS TARGETING OF TUMOR CELLS AND TUMOR-ASSOCIATED MACROPHAGES TO REPROGRAM GLIOBLASTOMA BY TUMOR-SUPPRESSIVE MICRORNA
Authors: Grace Nguyen, MinHye Noh, Alexandra Miller, Minxin Huang, Yulin Dai, Zhongming Zhao, Ji Young Yoo, Tae Jin Lee
Journal: Neuro-Oncology (2024)

Abstract Glioblastoma (GBM) is the most aggressive type of primary brain tumors due in part to cell-intrinsic and cell-extrinsic mechanisms. The ability of GBM tumor to not only resist conventional therapies but also induce an immunosuppressive tumor microenvironment (TME) is thought to underlie the failure of immunotherapies. Thus, strategies to target both tumor cells and immunosuppressive immune cells, such as tumor-associated macrophages (TAMs), are of great interest. The ability of microRNA (miRNA) to target multiple genes is favorable to alter the character of the TME and cancer cells. Previously, we have shown that tumor suppressive miRNA, miR-138, can effectively regulate the genes in GBM cells relating to cell proliferation and viability. The exogenous delivery of miRNAs, however, has been limited due to the lack of delivery mechanisms that minimize off target effects. We argue that extracellular vesicles (EVs) are an ideal modality of targeted delivery for therapeutic miRNA, which we can accomplish by decorating the EV surface with cancer specific ligands, such as folate. Here, we report that trypsin digestion of the EV surface can increase the surface labeling efficiency for cancer targeting ligands. Folate-labeled trypsinized EVs effectively targeted folate receptor (FR) positive GBM cells and TAMs, delivering miR-138 in in vitro and in vivo orthotopic intracranial murine models of GBM. This simultaneous delivery decreased cancer cell proliferation and altered macrophage polarization through the inhibition of known target genes, phenotypically reprogramming both cancer cells and TAMs. To our knowledge, this is the first preclinical study attempting to target both tumor cells and innate immunity by delivering tumor suppressive miR-138 using a trypsinized EV-based RNA delivery system. These findings can be rapidly translated into a novel therapeutic option for GBM patients.
EXTH-85. ASSESSMENT OF ANTI-CD69 ANTIBODY THERAPY ALONE OR IN COMBINATION WITH ANTI-PD-1 IN MURINE GBM
Authors: Michal Nisnboym Ziv, Gary Kohanbash, Itay Raphael
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Glioblastoma multiforme (GBM) is an aggressive central nervous system malignancy with a dismal prognosis. There is continued interest in trying multiple immunotherapy modalities for this intractable cancer. Cluster of differentiation 69 (CD69), is an early marker of T and NK cell activation. CD69 play multiple roles in T cell-mediated immunoregulation with immune inhibitory role in antitumor immunity. Previous preclinical work in non-CNS malignancies has demonstrated that targeting CD69 can improve clinical outcome and anti-tumor immunity. We aimed to assess anti-CD69 Ab therapy alone or in combination with anti-PD-1 in murine GBM. METHODS We explored transcriptomic data from 163 GBM patients using the TCGA database. We then tested the therapeutic value of anti-CD69 immunotherapy in a preclinical model of GBM and assessed the ideal timing of treatment with anti-CD69 Ab by evaluating survival and immune tumor-microenvironment by flow cytometry. Two treatment-timings with anti-CD69 Ab were further evaluated either alone, or in combination with anti-PD1 Abs and compared to control and to anti-PD1 only treatment. Survival data was collected. RESULTS CD69 expression was significantly increased in GBM patients tissues as compared with normal brains and increased CD69 expression was associated with worse progression-free survival. Treatment-timing with single dose anti-CD69 Ab at day 1 or three doses at days 4, 8 and 12 post tumor-injection minimally improved the median survival time of animals. In addition, effective CD69 blockage and significantly elevated PD-1 expression on NK cells was found in these timings, making them good candidates to evaluate anti-CD69 Ab therapy alone or in combination with anti-PD-1 Ab. However, when assessing these treatment-timings with anti-CD69 Ab alone or in combination with anti-PD1 no survival benefit was found. CONCLUSION This is the first study assessing anti-CD69 Ab therapy alone or in combination with anti-PD-1 in murine GBM. While some effect was found on the cellular level, this didn’t translate to survival benefit and results are overall negative.
TMIC-42. CONQUERING SPP1+ MYELOID-DRIVEN RESISTANCE OF GLIOBLASTOMA TO IL13RA2-TARGETED CAR T CELL THERAPY
Authors: Sharareh Gholamin, Heini M Natri, Yuqi Zhao, Shengchao Xu, Maryam Aftabizadeh, Begonya Comin-Anduix, Supraja Saravanakumar, Christian Masia, Robyn Wong, Lance Peter, Mei-i Chung, Evan D Mee, Brenda Aguilar, Renate Starr, Davis Y Torrejon, Anusha Kalbasi, Darya Alizadeh, Xiwei Wu, Antoni Ribas, Stephen Forman, Behnam Badie, Nicholas E Banovich, Christine E Brown
Journal: Neuro-Oncology (2024)

Abstract In the evolving landscape of glioblastoma (GBM) therapy, the recent proliferation of clinical trials exploring chimeric antigen receptor (CAR) T cell interventions has garnered attention, although their therapeutic efficacy remains limited. Despite recent progress in elucidating the role of the GBM microenvironment in immunotherapy resistance, particularly regarding intercellular networks and macrophages, significant ambiguities endure, impeding a comprehensive understanding of resistance mechanisms amidst the patient-specific heterogeneity of the tumor microenvironment (TME). In this study, we utilized single-cell RNA sequencing to analyze tumors from 41 glioma patients undergoing IL13Rα2-targeted CAR T cell therapy. Our findings unveiled heightened suppressive extracellular network signatures, particularly SPP-1, predominantly observed within myeloid cells from non-responsive patients. The clinical significance of both SPP1+ myeloid cell abundance and overall expression levels revealed associations with patient outcomes. Subsequently, transcriptomic insights were translated to myeloid cell functions in patients exhibiting high versus low SPP1 expression. SPP1-expressing macrophages displayed diminished antigen presentation, phagocytosis, and cell-mediated cytotoxicity, along with augmented extracellular matrix biogenesis and degradation, iron efflux, and suppressive interleukin pathways. Moreover, SPP1-high macrophages exhibited enhanced ligand-receptor interactions, implying a predisposition towards suppressive activities. Immunometabolism pathways, including lipid and ketone body biogenesis and regeneration, were upregulated in SPP1-expressing macrophages, indicating an increased reliance on non-glycolysis-mediated ATP production. To assess translational implications, the therapeutic efficacy of SPP1 blockade was evaluated in a syngeneic glioma model. Blockade of SPP1 with an anti-SPP1 antibody prior to CAR T cell infusion effectively mitigated the immunosuppressive milieu, reversing resistance in preclinical GBM models to murine IL13Rα2-targeted CAR T cell therapy. Subsequent profiling of tumors post-treatment provided insights into TME alterations following SPP1 blockade therapy. This investigation illuminates the intricate interplay between the TME and CAR T cell therapy resistance in GBM, underscoring SPP1 as a promising therapeutic target to surmount CAR T cell resistance and enhance treatment outcomes.
PATH-60. AUTOMATED QUANTIFICATION OF KI-67 PROLIFERATION INDEX BASED ON WHOLE SLIDE IMAGES IN PEDIATRIC BRAIN TUMORS
Authors: Ariana M Familiar, Anahita Fathi Kazerooni, Meen Chul Kim, Adam Kraya, Phillip J Storm, Derek Oldridge, Angela Viaene, Adam C Resnick, Ali Nabavizadeh
Journal: Neuro-Oncology (2024)

Abstract The use of AI methods with histopathological images (pathomics) has strong potential to aid pathologists in pediatric brain cancer diagnosis and prognosis given the morphological and molecular heterogeneity of these tumors. However, use of pathomics in this context has been relatively limited. One example is the IHC-based tumor proliferation index (percentage of Ki-67 positive cells amongst all malignant cells) which is often routinely reviewed by pathologists clinically but remains to be objectively quantified or reported in a standardized manner. As a result, analysis of this marker across patients at-scale and in data-driven methods remains largely hindered. Here, we explore the extension of an automated deep learning AI tool (DeepLIIF), originally trained and validated with adult breast/prostate/liver data, for quantification of Ki-67 index from digitized whole slide images of a cohort of pediatric brain tumors from the Children’s Brain Tumor Network (N=834). We find that derived Ki-67 scores largely agreed with neuropathologist-reported Ki-67 activity in original clinical notes and could be used to successfully stratify glioma/astrocytoma patients (N=200) into low- and high-grade groups (LGG: M=11.6; SEM=1.2; HGG: M=18.7; SEM=2; p=0.001). Ki-67 scores were also related to the survival status of the patients (Alive: M=11.8; SEM=1.1; Deceased: M=18.8; SEM=2.2; p=0.003). Summary statistics across tumor types (glioma, astrocytoma, medulloblastoma, ATRT, ependymoma, etc.) and molecularly defined subtypes are also compared, providing direct insights into distributional properties between these groups that has not previously been feasible. Our results show the ability of AI-powered methods to quantify routine histopathology metrics with little human input, allowing objective comparisons between patients and opening the door for precision medicine approaches with predictive analytics in clinical contexts.
NIMG-12. EVALUATING THE SUPER T2-FLAIR MISMATCH SIGN IN OLIGODENDROGLIOMA, IDH-MUTANT AND 1P/19Q CODELETED
Authors: Iori Ozono, Fumiyuki Yamasaki, Shumpei Onishi, Ushio Yonezawa, Akira Taguchi, Novita Ikbar Khairunnisa, Nobutaka Horie
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND We reported the super T2-FLAIR mismatch sign as a prognostic imaging biomarker for non-enhanced astrocytoma, IDH-mutant, CNS WHO grade 2 or 3. However, it remains unclear whether this novel imaging biomarker is applicable for oligodendroglioma, IDH-mutant and 1p/19q codeleted. METHODS We conducted a retrospective evaluation of non-enhanced oligodendroglioma, IDH-mutant and 1p/19q codeleted, including 14 cases from at our institute and 15 cases from TCGA/TCIA database. We defined “super T2-FLAIR mismatch sign” positivity as having a significantly strong low signal comparable to cerebrospinal fluid, rather than just a pale FLAIR low-signal tumor region as in regular T2-FLAIR mismatch. We evaluated the presence or absence of T2-FLAIR mismatch sign and super T2-FLAIR mismatch sign using preoperative MRI and statistically analyzed the progression-free survival (PFS) and overall survival (OS) using log-rank test. RESULTS The median age of this patient group was 47 (ranging 20-77) years and consisted with 16 males and 13 females. There were 27 cases of grade 2 and two cases of grade 3. The regular T2-FLAIR mismatch sign was observed in three cases (10%) (grade 2: 2 cases, grade 3: 1 case). While the super T2-FLAIR mismatch sign was observed in three cases (10%) (grade 2: 2 cases, grade 3: 1 case). One case had both regular and super T2-FLAIR mismatch signs. The mean follow-up period was 33.4 months, during which there were 3 cases of progression and 1 death. Both regular and super T2-FLAIR mismatch sign were not associated with PFS, OS. CONCLUSIONS The presence of the super T2-FLAIR mismatch sign was not associated with prognosis in oligodendroglioma, IDH-mutant and 1p/19q codeleted. Because the sample size was insufficient, further larger investigation through is needed to assess the utility of this sign.
EXTH-84. A DURABLE RECURRENT INTRACEREBROVENTRICULAR INFUSION METHOD IN MICE FOR PRECLINICAL ASSESSMENT OF CELLULAR THERAPEUTICS
Authors: Chao-Hsien Chen, Michael Curran
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND Significant advancement in cellular treatments for glioblastoma has been made in recent years. The administration route has shifted from intravenous access to local delivery, namely intracerebroventricular (ICV) delivery, in order to prevent the injected cellular products from becoming trapped in peripheral organs such as liver and spleen. There is currently no reliable preclinical system available to accurately examine new cellular treatments that involve long-term recurrent infusion into the cerebral ventricles. METHOD We optimized the surgical device and technique by modifying a commercially available ICV device with a predetermined needle length, eliminating the requirement for spacers hence relieving the tension of the surgical wounds. To avoid skin puncture, we substituted the tunneled catheter with a silicon catheter. The surgical incisions were secured with autoclips in replacement of sutures. We administered periodic infusions of engineered monocytes on a weekly basis using the tunneled catheter for a duration of 8 weeks. The rate of wound dehiscence was monitored. RESULTS The delivery of the engineered monocytes to the cerebral ventricle via the ICV device has been confirmed using a bioluminescence-based imaging. The device and the tunneled catheter demonstrate a long-lasting durability for a minimum of 8 weeks. The optimized device and method effectively reduce the occurrence of post-operative wound dehiscence. Using a silicon catheter minimizes skin punctures. CONCLUSION Our optimized ICV device, material, and surgical approach offer a dependable preclinical instrument for the long-term and recurrent delivery of cellular therapies that reflect patients’ clinical treatment schedules and provide a more accurate evaluation of their translational potential.
NCOG-41. COMPARATIVE ANALYSIS OF MORTALITY AND SHORT-TERM SIDE EFFECTS IN PATIENTS WITH GLIOBLASTOMA MULTIFORME TREATED WITH TEMOZOLOMIDE VERSUS TEMOZOLOMIDE PLUS BEVACIZUMAB CHEMOTHERAPY
Authors: Greta Sallese, Anuttham Kandhadai, Paul Brindley
Journal: Neuro-Oncology (2024)

Abstract INTRODUCTION Glioblastoma multiforme (GBM) is a highly aggressive primary brain tumor in adults with limited treatment options and poor prognosis. Temozolomide (TMZ) chemotherapy is the standard treatment for GBM, but alternative therapies have shown limited success. Bevacizumab (BEV), a monoclonal antibody targeting vascular endothelial growth factor (VEGF), is used to restrict GBM growth and spread. This study evaluates the efficacy of combining TMZ with BEV compared to TMZ alone in managing GBM. METHODS A retrospective cohort study was conducted using TriNetX database data, focusing on patients diagnosed with GBM and receiving chemotherapy. Cohorts were defined by treatment: TMZ plus BEV versus TMZ alone. Propensity-score matching balanced baseline characteristics, including demographics and health conditions. Primary outcomes included mortality rates and short-term side effects within the first year of treatment, such as cognitive communication deficits, headache, dizziness, insomnia, and nausea/vomiting. RESULTS After matching, 922 patients were included in each cohort. There were no significant demographic differences post-matching. The mortality rate was higher in the TMZ plus BEV group compared to TMZ alone (51.30% vs. 36.98%, RR: 1.387, 95% CI: 1.249-1.541). However, TMZ plus BEV was associated with a lower incidence of cognitive communication deficits (1.95% vs. 4.34%, RR: 0.45, 95% CI: 0.26-0.779) and dizziness (7.27% vs. 10.52%, RR: 0.691, 95% CI: 0.513-0.93). No significant differences were found in headache, insomnia, or nausea/vomiting rates between the groups. CONCLUSION This study indicates that combining bevacizumab with temozolomide may increase mortality in GBM patients but reduce certain side effects such as cognitive deficits and dizziness. These findings emphasize the need to carefully consider the benefits and risks of different chemotherapy regimens for GBM and highlight the necessity for further research to optimize treatment strategies and improve patient outcomes.
NIMG-81. PREDICTING TUMOR PROGRESSION WITH FIBER DENSITY-WEIGHTED WHITE MATTER PATHLENGTH MAPS IN PATIENTS WITH GLIOBLASTOMA
Authors: Bo Liu, Tiffany Ngan, Angela Jakary, Nate Tran, Paul Rowley, Steve Braunstein, Olivier Morin, Hui Lin, Janine Lupo
Journal: Neuro-Oncology (2024)

Abstract PURPOSE Although histopathological evidence indicates that glioma cells preferentially migrate along large white-matter bundles, standard-of-care (SOC) radiation therapy (RT) planning remains an isotropic expansion of the anatomical lesion. We hypothesize that anisotropic expansion of RT target volumes along white-matter pathways using fiber density-weighted, white-matter pathlength maps (DW-WMPLMs) derived from diffusion tensor imaging (DTI) could improve the prediction of tumor cell migration beyond surgical margins by a deep learning model compared to SOC clinical target volumes (CTVs). METHODS DTI and anatomical MRI from 118 patients newly-diagnosed with glioblastoma were retrospectively analyzed with anatomical imaging from post-surgical resection and latest progression scan before intervention. Parallel-transport tractography seeded from the pre-surgery T2-lesion was used to estimate white-matter fiber propagation. Fibers that intersected with the resection cavity were weighted by their density to control the length of expansion and create a DW-WMPLM that was used together with T2-FLAIR and T1-post-contrast images as inputs to a novel 3D-Swin-UNetR network, trained to predict the recurrence region using 4-fold cross-validation and evaluated in a holdout test-set (95/23 CV/test). New weighted-overlap, coverage, and sparing indices were introduced to evaluate coverage of the progressed lesion and healthy brain excluded. RESULTS 52% of patients had progression outside the standard 2cm-isotropic CTV margin, motivating the need for anisotropic CTVs. Our novel DW-WMPLMs had 87±20% and 83±18% overlap with contrast-enhancing and T2-lesion progression, respectively. The deep-learning model trained with DW-WMPLMs and anatomical images achieved 19% and 56% higher Dice and weighted-overlap indices compared to the isotropic 2cm-CTV(p&amp;lt;0.02), with less normal brain included. CONCLUSION This study demonstrates the feasibility and benefit of incorporating a novel metric of white-matter track characterization into deep learning progression prediction models of glioblastoma for RT-planning. Current work is validating findings in a prospective cohort acquired immediately prior to RT and incorporating other imaging metrics.
BIOM-64. EXPLOITING CELL-FREE DNA TO DISSECT MECHANISMS OF RESISTANCE TO TEMOZOLOMIDE IN GLIOBLASTOMA CELLS
Authors: Sharvari Mankame, Maria Kyriakidou, Nanyun Tang, George Reid, Micheal Berens, Floris P Barthel
Journal: Neuro-Oncology (2024)

Abstract Temozolomide (TMZ) is a cytotoxic alkylating agent that serves as a cornerstone in glioblastoma (GBM) treatment, yet is notorious for eliciting hypermutation in recurrent tumors that have developed drug resistance by downregulating mismatch repair (MMR). We reasoned that cell-free DNA (cfDNA), a non-invasive measure for detecting tumor-derived biomarkers, could be used to temporally examine the mechanism of resistance to TMZ. We therefore designed an in-vitro experiment using the patient-derived GBM43 cell line. Over five days, batches of cells were treated with either TMZ or vehicle. Cell counts and cfDNA were collected every 24 hours. We observed an associated increase in both dead cell counts and cfDNA yield in treated cells compared to untreated cells. In TMZ-treated samples, cfDNA showed a periodic fragmentation pattern consistent with internucleosomal cleavage and TMZ-induced apoptosis. Intriguingly, higher numbers of variants were found in the cfDNA of untreated samples when compared to treated cfDNA, possibly reflecting TMZ-induced selection of resistant subclones in treated samples. This was further supported by the finding that the average variant allele frequency (VAF) increased over time in TMZ-treated samples, consistent with purifying selection. Conversely, cfDNA from vehicle-treated samples demonstrated a decrease in the average VAF over time, consistent with clonal diversification. Although we did not observe an enrichment of the TMZ-associated mutational signature SBS11, we did find higher levels of defective MMR mutation signature SBS44 in treated samples, potentially indicating the selection of subclones with defective MMR mechanisms. Overall, our preliminary findings show that cfDNA can be used to resolve mechanisms of TMZ resistance over time. We are addressing open questions by performing longer treatment times, testing other patient-derived cell lines, and performing murine xenotransplantation experiments to test TMZ-associated hypermutation in vivo. Our work will contribute to our understanding of TMZ resistance, and importantly push the development of cfDNA-based biomarkers for measuring TMZ-sensitivity in patients.
CNSC-56. DIVERSE, FUNCTIONAL NEUROTRANSMITTER RECEPTOR EXPRESSION ON GLIOBLASTOMA CELLS ENABLES EXTENSIVE NEURON-TO-GLIOMA COMMUNICATION
Authors: Julia Wagner, Svenja Tetzlaff, Ekin Reyhan, Varun Venkataramani
Journal: Neuro-Oncology (2024)

Abstract Glioblastomas are invasive yet incurable brain tumors. Recent data have shown that glutamatergic neuron-to-glioma synapses drive glioblastoma proliferation and invasion. In this study, we set out to investigate whether glioblastoma could communicate with neurons via various neuron-derived neurotransmitters through a functional neurotransmitter receptor screening. For this purpose, we stably transduced glioblastoma cells with a genetically encoded calcium indicator and sequentially and locally applied eight different neurotransmitters to glioblastoma cells in neuron-glioma co-cultures. These neurotransmitters included acetylcholine, ATP, dopamine, glutamate, GABA, adrenaline, serotonin, and glycine. We observed functional responses to acetylcholine, glutamate, ATP, dopamine, indicating a potential role for diverse neuron-to-glioma communication. Further, we investigated in patient-derived xenograft models and human tissues the existence of putative neuron-to-glioma synapses that could signal via acetlycholine, ATP and dopamine. In conclusion, this study reveals that glioblastoma cells express a heterogeneous set of functional neurotransmitter receptors, which may facilitate neuron-to-tumor communication across broad neuronal populations and warrant further investigation into their role for tumor biology.