bluuebunny/crossref_metadata_2025_split huggingface dataset:
TMIC-81. INCREASED LEVEL OF IGFBP2 PROMOTES TUMOR METASTASIS IN SHH MEDULLOBLASTOMA
Authors: Kunhiraman Haritha , McSwain Leon , Shahab Shubin , Kenney Anna 
Published: November 2022

Abstract
Medulloblastoma (MB) is the most common pediatric brain malignancy. MB comprises 5 major subgroups known as WNT, SHH p53wt, SHH p53mut, Group 3 and Group 4. Among the four MB subgroups SHH group is the most dominant molecular subgroup in infants and adults. These tumors are proposed to arise from cerebellar granule neuron precursors (CGNPs), whose developmental expansion requires SHH signaling from the neighboring Purkinje neurons. Previous reports suggest that SHH group features a unique tumor microenvironment compared with other MB groups. To better understand how SHH MB cells interact with Tumor Microenvironment, we performed cytokine array analysis of culture media from SHH group Patient Tumor cells, spontaneous SHH MB mouse tumor cells and SHH MB cell lines. Further, confirmed these results using ELISA, Western blot, and immunofluorescence from human SHH MB cell lines, Smo/A1 mouse tumor primary cells and PZp53Med cell lines. In continuation to the observation of IGFBP2 expression in various cell types in single cell analysis, we analyzed the presence of IGFBP2 in astrocytes using Smo/A1 mouse tumor Immunohistochemistry. Our data showed increased levels of IGFBP2 produced by SHH MB cell lines compared to others. We analyzed the role of IGFBP2 in SHH MB tumor growth and metastasis. IGFBP2 knock-down stable cell lines showed phenotypic changes including reduced cell proliferation, cell migration and EMT. Further western blot analysis of IGFBP2 KD cells showed reduced expression of EMT markers also reduced the activation of STAT3. Our preliminary in vitro data suggest IGFBP2 exerts it metastasis-promoting role in SHH MB by regulating the expression of EMT marker proteins and matrix remodeling proteins. Further functional studies suggest that in SHH MB, IGFBP2 may regulate a STAT3-mediated EMT program to metastasize. These findings provide a strong rationale for further pursuing how IGFBP2 promotes medulloblastoma tumor cell growth and migration in vivo.
TMIC-82. LIPOCALIN-2 MEDIATES CELL-INTRINSIC AND CELL-EXTRINSIC FUNCTIONS IN GLIOBLASTOMA
Authors: Wang Sabrina , Silver Daniel , Troike Katie , Deleyrolle Loic , Lathia Justin 
Published: November 2022

Abstract
Glioblastoma (GBM) is the most common primary brain tumor with a median survival of 17-20 months. Despite therapeutic treatments including surgery, radiation, chemotherapy, a subset of GBM clones, termed cancer stem cells (CSCs) are radio-resistant and chemo-resistant, leading to mortality of the patient. CSCs also have altered metabolic profiles and have an enhanced capacity to scavenge nutrients from their microenvironment, including iron. Lipocalin-2 (LCN2) functions to sequester iron and is traditionally considered an inflammatory marker through its function of limiting iron for bacterial usage. LCN2 has been described to have both a pro and anti-tumorigenic and has context-dependent functions depending on iron status. LCN2 has been shown to be important in brain metastasis, but its role in GBM is still largely unknown. To investigate how LCN2 plays a role in the GBM microenvironment, we orthotopically implanted syngeneic mouse GBM cells into male and female LCN2 knockout and wild-type mice. Female LCN2 knockout mice succumbed to tumors faster compared to males, revealing another example of sex differences in the tumor microenvironment. To assess a cell-intrinsic function for LNC2, we added recombinant LCN2 to mouse GBM cell lines and saw that proliferation also increased. When we probed for receptor expression in our knockdown cell lines, we saw that the LCN2 canonical receptor, SLC22a17, was upregulated in response. Furthermore, in a subset of slow-cycling cells of CSCs, LCN2 was shown to be up-regulated. Taken together, these data suggest that LCN2 functions in an iron-dependent manner to affect proliferation and sex-specific tumorigenesis. Given the fact that males have more iron than females, it is worth investigating the role of iron in GBM sex difference progression and therapeutic targets.
CNSC-32. ACTIN SUBUNIT STRUCTURAL DIVERSITY IN SHH MEDULLOBLASTOMA: IMPLICATIONS FOR CANCER BIOLOGY AND NEURODEVELOPMENT
Authors: Beaulieu Jamie , Knapp David , Picard Daniel , Remke Marc , Sadikot Abbas , Diaz Roberto 
Published: November 2022

Abstract

BACKGROUND
Altered expression of actin subunits is found in multiple cancers. Alpha-cardiac actin (ACTC1) is expressed in sonic hedgehog medulloblastoma (SHH MB) and regulates both cell survival and migration. We hypothesized that cardiac actin has a unique structural and functional role in SHH MB and may be expressed in post-natal granule cell progenitors (GCPs) which share similar gene expression profiles.

METHODS
Actin subunit protein expression (ACTC1, ACTB, ACTG1, and ACTA2) was evaluated by mRNA expression profiling within established datasets and across MB cell lines by Western blot (WB). Immunofluorescence microscopy was performed to assess intracellular actin subunit localization. The composition of each subunit in filamentous (F-) actin was evaluated. Furthermore immunoprecipitation of filamentous ACTC1 was performed to assess protein-protein interactions. The ratio of F-actin to globular (G-) actin was determined by WB in SHH MB cells exposed to mitotic inhibitor. Cell viability was determined by colony formation following over-expression of dominant-negative mutant ACTC1 (P116C & G247D).

RESULTS
ACTC1, ACTG1, and ACTB are the predominant actin subunits in SHH MB. Immunofluorescence microscopy demonstrated co-localization of ACTC1 with ACTG1 and ACTB but not ACTA2. ACTC1 showed a unique cortical localization pattern. Post-natal MATH1 positive mouse GCPs (P3-5) demonstrate similar distribution of ACTC1 in cortical F-actin. WB analysis of ACTC1 pulldown from SHH MB cell F-actin fractions showed co-precipitation with ACTG1 and ACTB but not ACTA2. ACTC1 F-actin to G-actin ratio is maintained in cells that show resistance to mitotic inhibition. Expression of mutant ACTC1 G247D resulted in reduced cell survival.

CONCLUSIONS
ACTC1 subunit is incorporated into F-actin in SHH MB and GCPs. Filamentous ACTC1 forms a protein complex with ACTG1 and ACTB. Disruption of ACTC1 polymerization results in reduced cell survival. These findings suggest a functional role of ACTC1 in both SHH MB and in GCPs which are important in cerebellar development.
MODL-07. Sensitivity of Tumor Treating Fields (TTFields) treatment planning to tumor segmentation errors
Authors: Ze’evi Oshrit , Marciano Tal , Naveh Ariel 
Published: November 2022

Abstract
Tumor Treating Fields (TTFields) are electric fields that disrupt cellular processes critical for cancer cell viability and tumor progression. TTFields are administered through two pairs of capacitive arrays placed on the patient’s scalp. The effect of TTFields has been shown to be dose dependent. An in-silico study based on imaging and survival data from the phase 3 EF-14 study demonstrated a correlation between simulated field intensity and overall survival. Novocure is developing a simulation-based patient-specific treatment planning system aimed towards maximizing TTFields dose delivered to the patient’s tumor. Different options are presented to the treating physician that are ranked based on dose. To create patient-specific planning, physicians are required to segment the pathological tissues on a T1-weighted MRI. These tissues may include the enhancing tumors, resection cavity and necrotic core. Segmentation of medical images is an error-prone procedure. Such errors may influence the calculation of expected TTFields dose delivered to the tumors. In this work, we examined how different segmentations of the tumors affect the delivered dose, by placing mock tumors of different compositions within a simplified ellipsoidal model. Simulations were then used to assess field distributions in these tumors. Tumors of different enhanced volumes were then compared by LMiPD values. Our results show that 10% differences in the segmented enhancement result in less than 5% relative error in LMiPD. To enforce the validity of the simplified model, we performed the same analysis for two patient specific models. In both cases, the relative difference in segmentation was about 5%, and consequent errors in LMiPD was &lt;5% as well. In conclusion, when using a simulation-based TTFields treatment planning system, small differences in the segmentation of the enhancing component of mock glioblastoma tumors in both simplified ellipsoid and patient specific models lead to small differences in LMiPD.
MODL-10. SYSTEMATIC CHARACTERIZATION OF GLIOBLASTOMA GROWTH PATTERNS REVEALS INVASION ROUTE-SPECIFIC FUNCTIONAL SIGNATURES AND DRUG VULNERABILITIES
Authors: Krona Cecilia , Rosén Emil , Kundu Soumi , Olausson Karl Holmberg , Larsson Ida , Elfineh Ludmila , Doroszko Milena , Elgendy Ramy , Wikström Johan , Jörnsten Rebecka , Nelander Sven 
Published: November 2022

Abstract
Glioblastomas (GBMs) are malignant brain tumors characterized by uncontrolled, invasive growth along multiple anatomical pathways. GBM is well-studied on a genetic and molecular level, but clinically relevant, experimentally tractable models of invasive growth are largely lacking. We report an integrated study of patient-matched information including clinical and radiological data, patient-derived xenografts, genomics, transcriptomics, epigenomics, and drug response data. Our hypothesis is that joint variation across these levels can expose treatments and biomarkers associated with glioblastoma invasion and recurrence. In total, 64 patient-derived cell lines (PDCLs) were injected into the striatum of n &gt;= 4 mice each, of which 45 PDCLs successfully formed tumors. The tumor-forming PDCLs were each scored with respect to 10 distinct growth characteristics (n= 182 mice). The repertoire of phenotypes was highly divergent and included clear cases of perivascular invasion, white matter invasion, perineuronal satellitosis, and gliosarcoma. We explored if cellular pathways, monitored by RNA sequencing, could account for these differences. DNA repair, Wnt-, and Notch-pathways were predictive of tumor initiation, whereas pathways related to hypoxia, metabolic reprogramming, cellular stress, and inflammation reduced tumor initiation capacity of PDCLs. Transcriptional signatures were also strongly predictive of route-specific invasion. Diffuse invasion was predominantly seen in classical-subtype PDCLs with astrocytic or outer radial glia-like signatures. Proneural PDCLs, in turn, grew as solid tumors with an invasive peripheral region, and mesenchymal tumors were demarcated and invaded around vasculature. To explore the therapeutic implications of our findings, we used our data-driven method TargetTranslator to predict the drug vulnerabilities of different types of invasive glioblastoma. Transcriptional signatures of diffusively growing tumors suggested a vulnerability to neuroactive substrates while perivascular invading tumors would be more susceptible to CDK- and RTK inhibitors. We expect that focusing on drivers of these functional signatures will greatly facilitate the search for effective compounds targeting distinct growth behaviors.
MODL-11. NOVEL IMMUNOTHERAPY MODEL IN AGGRESSIVE PEDIATRIC H3K27M MUTANT GLIOMAS WITH INDUCIBLE TGFBR2 AND LAG3 EXPRESSION
Authors: Ljubimov Vladimir , Linesch Paul , Sabet Sara , Krutikova Viktoria , Mehdikhani Shaunt , Pacheco David Rincon Fernandez , Danielpour Moise , Breunig Joshua 
Published: November 2022

Abstract

INTRODUCTION
Gliomas are considered immunologically “cold” tumors that mask themselves from the immune system. Immunotherapy, a breakthrough for cancer treatment, remains inefficient for gliomas. H3K27M mutant diffuse midline glioma has poor survival. Using our innovative mosaic analysis with dual recombinases technology (Cell 2019), we further created a novel murine model of H3K27M glioma with an inducible expression of LAG3 and TGFBR2 to make the tumor recognizable by the immune system. This allows studying molecular mechanisms of “perfect” immunotherapy in pediatric gliomas with histone H3.3 mutations.

METHODS
To make a novel murine model, H3K27M plasmids with doxycycline-inducible expression for TGFBR2 and LAG3 were designed, sequenced, and replicated. For in vitro validation, murine neuronal stem cells were nucleofected with these plasmids, grown and sorted. Doxycycline was added to the experimental group in vitro to induce expression. The plasmids were then electroporated into neonatal MGMT mice (n=21) of both genders. Control mice were used on a standard diet (n=9) and experimental mice (n=12) were given doxycycline in food to induce TGFBR2 and LAG3 expression in vivo. Mice were followed up for survival.

RESULTS
Plasmid sequencing validation demonstrated their high purity. In vitro nucleofected neuronal stem cells showed significant increase in TGFBR2 and LAG3 expression by immunofluorescent staining after addition of doxycycline. The mouse survival study showed a significant benefit with treatment group surviving 46% longer (135 ± 41.9 days vs. 92.6 ± 32.7 days in the control group, p=0.030). Conclusion and Future Directions: We have successfully modified H3K27M glioma to have inducible expression of TGFBR2 and LAG3 to simulate “perfect” immunotherapy. The survival study showed a significant survival benefit. The development of organoid transplants for more uniform testing and next-generation sequencing is ongoing. This can lead to the emergence of novel immune therapies and uncover novel mechanisms of tumor response to treatment.
MODL-17. SEGMENTATION OF PRE AND POST-TREATMENT GLIOMA TISSUE TYPES INCLUDING RESECTION CAVITIES
Authors: White Nathan , Baig Saif , Vidic Igor , Mastorakos George , Smith Robert , Dale Anders , McDonald Carrie , Beaumont Thomas , Seibert Tyler , Peddi Srinivas , Hattangadi-Gluth Jona , Farid Nikdokht , Kesari Santosh , Rudie Jeffrey 
Published: November 2022

Abstract

PURPOSE
Measuring gliomas is a time-intensive process with significant inter-rater variability in post-surgical residual tumor and resection cavities. This likely contributes to the delayed assessment of progression and in-field recurrences from radiation. Automated segmentation of pre and post-treatment gliomas could reduce inter-rater variability and increase workflow efficiency for routine longitudinal radiographic assessment and treatment planning. We evaluated whether a 3D neural network is comparable to expert assessment of pre and post-treatment diffuse gliomas tissue types and resection cavities.

METHODS
A retrospective cohort of 647 MRIs of patients with diffuse gliomas (average 55.1 years, 45% female, 396 pre-treatment and 251 post-treatment, median 237 days post-surgery) from The Cancer Imaging Archive were stratified by operation status and tumor grade and randomly split into training (536) and testing (111) samples. T1, T1-post-contrast, T2, and FLAIR images were registered, skull-stripped, and interpolated to 1x1x1. Four classes — edema/infiltrative/post-treatment changes (ED), enhancing tissue (ET), necrotic core (NCR), and resection cavities (RC) — were manually segmented by an expert neuroradiologist. Using these segmentations and the four input image modalities, a nnU-Net, a state-of-the-art 3D U-Net convolutional neural network, was trained to predict segmentations of the four classes.

RESULTS
Segmentation performance in the test set for the ED, ET, and RC classes was at the level of inter-rater reliability with median Dice scores ranging from 0.85 to 1 and relative volume errors ranging from -0.05 to 0.02. There was a near-perfect correlation between manually segmented and predicted total lesion volumes (r2 values ranging from 0.95 to 0.98 among classes).

CONCLUSIONS
Accurate, automated volumetric quantification of diffuse glioma tissue volumes may improve response assessment in clinical trials and reduce provider burden and errors in measurement.
MODL-23. MULTISCALE MODELS OF GLIOMA PROGRESSION: INSIGHTS ABOUT VASCULATURE AND THERAPY EFFECTS
Authors: Conte Martina , Surulescu Christina , Dzierma Yvonne , Knobe Sven 
Published: November 2022

Abstract
Gliomas are the most prevalent, aggressive, and invasive subtype of primary brain tumors, characterized by fast cell growth, strong invasion capability, and well-developed tumor vasculature. Although the research advances and the clinical trials testing the efficacy of novel combined therapies have allowed significant progress in the comprehension and treatment of gliomas, these tumors are characterized by a poor prognosis, and recurrence remains the main cause of mortality. The growth and migration of tumor cells inside the brain is a highly complex phenomenon, influenced by a multitude of intrinsic and extrinsic factors at different spatial and temporal scales. The high complexity of this invasion process remains a challenge to face and several important questions are still unanswered. In this context, mathematical models emerge as powerful tools to face these challenges. Here, we propose a multiscale approach for the description of glioma progression under the influence of vascularization. Precisely, we firstly focus on the effects of (hypoxia-driven) acidity and phenotypic heterogeneity on tumor progression. Then, we extend the setting to include vascular endothelial growth factor evolution and compare various therapeutic approaches. Starting from a microscopic description of the interactions between specific cell membrane receptors and the extracellular microenvironment, we define two different coupled systems for endothelial and tumor cell evolution. The analysis of these systems allows us to assess tumor growth and spread on the basis of DTI and glioma patient data. In particular, we perform several data-driven numerical tests aimed at assessing the role of vasculature and phenotypic heterogeneity on tumor progression and comparing the effect of different combinations of radio-, chemo-, and anti-angiogenic therapy on it.
STEM-05. GLIOBLASTOMA NEUROSPHERES DISPLAY STEMNESS CHARACTERISTICS AND UPREGULATION OF THE VEGF-A PATHWAY
Authors: Mozaffari Khashayar , Chandra Neha , Aguirre Brian , Cherian Nina , Chandla Anubhav , Wadehra Madhuri , Yang Isaac 
Published: November 2022

Abstract

INTRODUCTION
Glioma stem cells (GSC) constitute a subpopulation of tumor cells with stem-cell like properties and are believed to enhance glioblastoma’s ability to grow and confer resistance against chemoradiotherapy. It has been shown that non-adherent three-dimensional (3D) growth conditions facilitate neurosphere formation and enable isolation of GSCs in vitro. This can serve as an invaluable tool to better understand the role of GSCs in glioblastoma pathogenesis.

OBJECTIVE
We aimed to evaluate differentially expressed genes in non-adherent versus adherent conditions using primary tumor glioblastoma cell lines; and to identify alterations in various signaling pathways that are paramount to their growth and maintenance. Furthermore, we targeted the EMP2-HIF1α axis, a proposed regulator of VEGF expression, to determine its effects on cell viability.

METHODS
Three primary tumor glioblastoma cell lines were generated and cultured under adherent or non-adherent growth conditions. Sequencing was performed on the Illumina HiSeq3000 system, and gene counts were normalized by TMM. A pair-wise statistical analysis of over 20,000 genes was performed between the two conditions. A p-value &lt; 0.05 was considered statistically significant.

RESULTS
After 72 hours of growth under 3D conditions, primary glioblastoma cells show an increase in stem-like properties, measured via an upregulation of SOX2 and nestin. RNA sequencing demonstrated a significant increase in expression of the following transcripts in 3D conditions compared to those grown on adherent plates: VEGF-A, EGFR, PDGFR-A, FGFR3, and TGFB2. Treatment with anti-EMP2 monoclonal antibodies significantly reduced cellular proliferation.

CONCLUSION
Our results demonstrate that neurospheres upregulate growth factor pathways to enable their survival in 3D conditions, suggesting an inherently different genetic landscape between differentiated tumor cells and GSCs. Future studies will investigate the cellular mechanisms responsible for upregulation of these genes; and to ultimately design more effective targeted therapeutic agents.
STEM-12. DISCOVERY THE ORIGIN-CELLS FOR HUMAN GLIOBLASTOMA GENESIS IN SUBVENTRICULAR ZONE
Authors: Yoon Seon-Jin , Choi Ran Joo , Oh Yoojung , Cho Se-Young , Kim Hyun Jung , Lee Joo Ho , Yeo Eunchae , Yoo Jihwan , Moon Ju Hyung , Kim Eui Hyun , Kim Se Hoon , Kim Huyn Seok , Chang Jong Hee , Kim Sangwoo , Kim Hoon , Lee Jeong Ho , Kang Seok-Gu 
Published: November 2022

Abstract
Human glioblastoma (GBM), originating from the subventricular zone (SVZ), occurs due to molecular disruptions in chromosomes. Most GBM tissues exhibit definitive chromosomal patterns: copy-number-variations (CNV) in chromosome 7 (gain) and 10 (loss), known as the earliest molecular events. Herein, we hypothesised that the origin-cells in SVZ of GBM patients can provide clues regarding these chromosomal alterations. We compared bulk RNA sequencing (RNAseq) data of GBM tumor tissue (n=126), tumour free GBM SVZ (n=40), and tumor-free control SVZ of non-glial tumor (n=9). Paired single-cell-level RNAseq samples of tumor free GBM SVZ (n=7) and GBM tumor tissue (n=10), were done to see cell specific CNVs. Using human SVZ and GBM samples as a background, we generated origin-cell and origin-cell-derived tumour cell using CRISPR/Cas9. In this work, we identified two GBM-origin-cell types with stem-cell signatures during single-cell level analyses of 60 SVZ tissue samples obtained from tumor-free regions of GBM patients. Furthermore, single-cell level analysis revealed that two origin-cell types in SVZ harbor ongoing patterns of CNV alterations. Among the origin-cells found in the SVZ of GBM patients, NO-like cells showed neural progenitor plus oligodendrocyte progenitor (NO) signature, while AN-like cells showed astrocyte plus neural stem cell (AN) signature. For the interconnectedness, we subjected single-cell-level RNA-seq data to ligand-receptor connection analysis. In the stem cell mode, NO-like cells was connected to AN-like cells in SVZ samples and while in the tumor samples, cycling cell was connected to AN-like cells. NO-like cells was common in TERT promoter wildtype GBM and AN-like cells was more common in TERT promoter mutant GBM. CRISPR/Cas9 models revealed accumulation copy-number alterations from non-tumorigenic origin-cells to tumor cells. These two origin-cells (NO-like cells and AN-like cells) derived from the SVZ of the adult human brain will facilitate the understanding of GBM genesis and development of potential novel therapeutic targets.