bluuebunny/crossref_metadata_2025_split huggingface dataset:
TMIC-15. HYPERACTIVATING THE HIPPO PATHWAY EFFECTOR TAZ DIFFERENTIALLY DISTORTS THE TUMOR MICROENVIRONMENT, PROMOTES TUMOR-ASSOCIATED NEUTROPHIL INFILTRATION, AND PHENOCOPIES MESENCHYMAL-GLIOBLASTOMA
Authors: Yee Patricia , Wei Yiju , Liu Zhijun , Guo Hui , Manjibhai Vekariya Umeshkumar , Anderson Benjamin , Li Wei 
Published: November 2019

Abstract
Glioblastoma (GBM), the deadliest and most common adult brain malignancy, is molecularly and clinically heterogeneous. The most common subtype (both primary and recurrent), mesenchymal (MES)-GBM, has the worst prognosis and highest treatment resistance. MES-GBM exhibits hyperactive transcriptional coactivator with PDZ-binding motif (TAZ), a Hippo tumor suppressive pathway effector whose expression in GBMs predicts short survival. Yet, how Hippo-TAZ dysregulation might drive GBM MES transition remains elusive, precluding subtype-specific treatments. Tumor evolution requires signaling dysregulation and co-opting the tumor microenvironment (TME). Understanding GBM heterogeneity was recently complicated by the notion that subtypes vary in TME immune composition. The MES-GBM TME is differentially-distorted in silico, with more tumor-associated macrophages/microglia (TAMs) and neutrophils (TANs). Yet, how TAZ hyperactivity, MES transition, and GBM TME distortion interrelate and impact tumor progression remains unknown. We suspected that TME distortion facilitates immune evasion, MES transition, and tumor progression, worsening treatment responses. To test this, we devised an orthotopic xenograft mouse model phenotypically and histopathologically recapitulating human MES-GBM by expressing constitutively-active TAZ (TAZ4SA) in human GBM cells lacking MES signatures (GBM4SA). GBM4SA mice lived significantly shorter compared to mice with GBM expressing vector (GBMvector) or mutant TAZ unable to bind its effector, TEAD (GBM4SA-S51A). Moreover, more myeloid cells infiltrate the GBM4SA TME than the GBMvector or GBM4SA-S51A TMEs. While most myeloid cells infiltrating the GBMvector and GBM4SA-S51A TMEs were TAMs, most infiltrating the GBM4SA TME were TANs, suggesting TAZ hyperactivation differentially distorts the TME. Next, to delineate the roles of TANs in GBM4SA tumor progression, mice were depleted of neutrophils by administering Ly6G antibody. Serial blood smears and flow cytometry revealed effective depletion was achieved. We are currently investigating the impact of systemic neutrophil depletion on GBM mesenchymal transition and tumor progression in hopes of informing future GBM clinical management and novel TME-targeted immunotherapies.
TMIC-24. COLONY STIMULATING FACTOR 1 INHIBITION DECREASES TUMOR GROWTH AND MACROPHAGE INFILTRATION, AND INCREASES NEUTROPHIL INFILTRATION IN XENOGRAFT MICE MODELS OF GLIOBLASTOMA
Authors: Khan Sabbir , Piao Yuji , Mittal Sandeep , McGee Kain , Park Soon , Alfaro-Munoz Kristin , Balasubramaniyan Veerakumar , DeGroot John 
Published: November 2019

Abstract
Glioblastoma (GBM) is the most common, highly aggressive and lethal primary brain tumor in adults, and has a median overall survival ranging from 12 to 15 months. Several human cancers including glioma are infiltrated with numerous immune cell types which play a critical role in tumor growth, invasion and resistance to treatment. Previous studies, including our group, have shown that resistance to anti-VEGF therapy is associated with myeloid cell infiltration and mesenchymal transition in GBM. Notably, most glioma patients have shown increase in CD68+ cells due to overproduction of colony stimulating factor 1 (CSF-1) by tumor cells, a growth factor for macrophages. Therefore, we hypothesized that CSF-1 inhibition may reduce macrophage and/or myeloid cell infiltration in glioma, thereby increasing animal survival as monotherapy or in combination with VEGF inhibitors in xenograft GBM mouse models. We tested two CSF-1R inhibitors (AZD 7507 and JNJ-28312141) alone and in combination with VEGF inhibition to prevent macrophage infiltration in xenograft GBM mouse models. CSF-1R and VEGF inhibitors reduced macrophage infiltration (F4/80 staining), tumor volume, and mesenchymal transition (YKL-40 staining), and there was a marginal survival benefit in this model. Interestingly, despite significant reduction in tumor macrophages, we observed a significant increase in neutrophil infiltration and hypoxia (HIF1α staining), particularly in the combinatorial treated. Considering these observations, we further evaluated tumor-associated neutrophil (TAN) infiltration in GBM patient tumors by fluorescence-activated cell sorting (FACS). FACS-isolated TANs were identified as CD11b+/CD15+/CD66b+ triple positive. Our results shown that the infiltrating TAN population vary from 0.5 to 5% in GBM patient tumors. Detailed characterization of TAN population and polarization in patient tumors are ongoing. Our findings revealed that CSF-1 and VEGF inhibition reduced macrophage infiltration and tumor growth, but significantly increased TAN infiltration which will likely hamper the potential therapeutic benefit of anti-CSF1-directed inhibitors.
TMIC-37. INTERCELLULAR COMMUNICATION BETWEEN NORMAL AND TUMOR CELLS IN GLIOMA MICROENVIRONMENT
Authors: Hossain Anwar , Hasan Irtiza , Adachi Satoshi , Ledbetter Daniel , McDonald Malcolm , Gumin Joy , Daou Marc , Phillips Lynette , Parker-Kerrigan Brittany , Lang Frederick 
Published: November 2019

Abstract
The interactions between tumors cells and their microenvironment are increasingly recognized as contributors to tumor growth and therapeutic resistance in glioblastoma (GBM). Mesenchymal Stem Cells (MSCs) have been implicated as components of the microenvironment of several cancers, but their contribution to GBM remains obscure. Recently we reported that GBMs contain cells resembling human mesenchymal stem cells, called Glioma-associated-MSCs (GA-hMSCs), based on our ability to isolate these cells from patient tumors (Figueroa, et al. Can Res 2017. 77, 5808–5819). In order to characterize the function of these cells in vivo, we used a PDGFRb promoter driven mouse model to track and modulate the behavior of endogenous MSCs (PDGFRb + cells). To generate tumors that mimic gliomas, we injected the RCAS-PDGF avian retrovirus into PDGFRb EGFP/nTVA mice. These mice express EGFP in PDGFRb expressing cells and RCAS receptor TVA under the control of the Nestin promoter and develop tumors. Immunostaining these tumors for GFP and CD31 determined that MSC like cells reside around blood vessels and are likely the major contributor of microvascular proliferation often seen in human gliomas. Additionally, we sought to see if there was communication between MSCs localized around blood vessels and the tumor. To this end, mice with Cre recombinase expression under the PDGFRb promoter were implanted with a GL-261 tumor harboring a dsRed/eGFP Cre recombinase/LoxP site. In these mice, tumor color change from red to green indicates transfer of Cre mRNA or protein from PDGFRb+ cells (MSCs) to tumor cells (GL-261dsRed/eGFP). We observed red to green transition in tumors, indicating that there is transfer of mRNA or protein, and further suggesting that there is direct communication between the tumor microenvironment and the tumor. Taken together, our findings emphasize the crucial role of MSCs in the tumor microenvironment.
TMIC-41. PROSTATE SPECIFIC MEMBRANE ANTIGEN EXPRESSION IN PRIMARY AND RECURRENT GLIOBLASTOMA
Authors: Lozinski Mathew , Fay Michael , Bowden Nikola , Graves Moira , Tooney Paul 
Published: November 2019

Abstract
Patients with glioblastoma almost always suffer a recurrence of an aggressive treatment resistant tumour and succumb within months highlighting the need to develop treatment options for recurrent glioblastoma. One potential target is prostate specific membrane antigen (PSMA) expressed on the new vessels in primary glioblastoma tumours. This study compared the expression of PSMA in primary and recurrent glioblastoma tumours. Formalin-fixed paraffin-embedded sections of primary and matched recurrent tumours from 13 patients with glioblastoma were processed for PSMA immunohistochemical labelling. PSMA expression was scored from digitally scanned sections using a categorical system (Total PSMA expression = PSMA label intensity (0–3) x percent PSMA-positive blood vessels). Little PSMA labelling was observed in any adjacent ‘unaffected’ brain tissue. PSMA was localised to blood vessels including those displaying microvascular proliferation in 12/13 primary and 9/13 recurrent glioblastoma tumours. Total PSMA expression scores ranged from 0 – 230 (maximum score = 300) and was divided into low and high expression based on a median split (median = 57) of PSMA expression across all tumours. Regression analysis showed a significant difference in PSMA expression between primary and recurrent glioblastoma (p = 0.04) with PSMA being highly expressed in ~70% of primary and only 31% of recurrent glioblastoma. Three cases displayed high expression in both primary and recurrent glioblastoma and one case had no PSMA expression at all. In conclusion, whilst higher expression of PSMA was detected in more primary tumours, 70%+ of all primary and recurrent tumours expressed PSMA to some extent adding evidence that this may be a useful target for treatment of glioblastoma. Larger cohorts and other techniques for detecting PSMA are needed to provide further evidence for PSMA’s utility as a target and to further define which glioblastoma patients are most likely to benefit from this approach.
TMIC-47. INHIBITION OF GLIOBLASTOMA GROWTH THROUGH TUMOR-MICROENVIRONMENT CROSSTALK USING CLINICALLY SUITABLE NANOBIOCONJUGATE
Authors: Galstyan Anna , Klymyshyn Dmytro , Patil Rameshwar , Ding Hui , Shatalova Ekaterina , Holler Eggehard , Ljubimov Alexander , Black Keith , Sun Tao , Ljubimova Julia 
Published: November 2019

Abstract
Tumor environment in glioblastoma (GBM) is a dynamic interactive complex between tumor, immune and stem cells and extracellular matrix (ECM). In 226 patient glioma samples, we found a clinical correlation between expression of tumor vascular laminin-411 (α4β1γ1) and cancer stem cell (CSC) markers: Notch pathway members, CD133, Nestin, and c-Myc, with faster tumor recurrence and shorter survival of patients (Tao S, et al, Cancer Res., 2019). Novel nanotechnology approach to block trimeric ECM laminin-411 was developed for GBM treatment in experimental and preclinical models on human U87MG and LN229, and patient-derived TS543 and TS576 GBM cell lines. Nanobioconjugates (NBC) based on natural polymer, poly(β-L-malic acid), with antisense against laminin-411 α4 and β-chains, endosome escape unit (Ding H, et al, PNAS, USA, 2010), antibodies for blood-brain barrier (BBB) crossing and tumor targeting was characterized for toxicity and biodistribution according to FDA guidelines. Ex vivo depletion of laminin-411 α4 and β1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of intracranial tumors in mice, and significantly increased survival in hosts compared to mice with untreated cells. A nanobioconjugate potentially suitable for clinical use and capable of crossing BBB was designed to block laminin-411 expression. In biodistribution studies the NBC labeled with 125I on tyrosines of attached antibodies was accumulated in GBM but not in healthy brain tissue. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, Notch signaling system through the b1 integrin-Dll4 (Notch ligand) pathway. No toxicity revealed in 4 naïve Cynomolgus macaques after administration of three therapeutic 1X and acute 10X dosages of NBC. Conclusion: An efficient strategy of GBM treatment was developed via targeting a critical component of the tumor microenvironment, laminin-411, which is independent of heterogeneous genetic mutations in glioblastomas. Support: NIH grants U01CA151815, R01CA188743, R01CA206220, R01CA209921.
TMIC-49. ABROGATING CD70 EXPRESSION IN GBM RESULTS IN A REDUCED IMMUNOSUPPRESSIVE TUMOR MICROENVIRONMENT
Authors: Tao Haipeng , Jin Linchun , Mendez-Gomez Hector , Long Yu , Na Meng , Hou Alicia , Karachi Aida , Lin Zhiguo , Deleyrolle Loic , Sayour Elias , Mitchell Duane , Huang Jianping 
Published: November 2019

Abstract

BACKGROUND
We found that CD70, as an immune modulator, in GBM plays a critical role in immunosuppression and tumor progression. Although CD70+ tumors recruit more CD3+ T cells than CD70— tumors do in patients with GBM, CD70 on GBM is also found to be involved in promoting CD8+ T cell death. The experiments by overexpressing or silencing CD70 in a primary tumor demonstrate that it can alter cell growth, survival, migration, and morphology of GBM cells. CD70 is negatively correlated with survival in patients with gliomas. These results suggest that CD70 is involved in immunosuppression in GBM.

OBJECTIVE
To determine if abrogating CD70 in tumor using CD70CAR-T cells could reverse the immunosuppressive microenvironment and enhance overall endogenous tumor immunity against both CD70+ and CD70— tumors, which might help to overcome a key obstacle— tumor-heterogeneity using single-targeted CAR-T cell therapy.

METHODS
CD70 was overexpressed (~75% positivity) in KR158 GBM line. Murine CD70CAR T cells were used to eliminate CD70+ tumors in an immunocompetent orthotopic tumor mouse model. Tumor-bearing mice were administered the CD70CAR T and vector-tranduced T cells, followed by IVIS imaging for tumor growth. The presentation and phenotype of CAR T cells and endogenous immune cell populations in tumors and spleens were measured.

RESULTS
Five weeks post treatment, CD4+ T cells were found to be the dominant T cell population in tumors for both CAR-T and endogenous T cells. While the CAR-T cells shrank the tumors, fewer PD-1 expressing endogenous T cells, as well as granulocytic MDSC, but not monocytic MDSC were observed in the tumor (not in spleen) for the CAR-T group, compared to the vector group. No significant changes were seen for NK cells and Tregs between the groups.

CONCLUSION
This study suggests that eliminating CD70+ tumor cells may reverse the immunosuppressive landscape of the tumor microenvironment.
TMIC-55. CHARACTERIZATION OF TUMOR-MICROENVIRONMENT INTERACTIONS IN GLIOBLASTOMAS AT THE SINGLE-CELL LEVEL
Authors: Rao Rohit , Zhang Feng , Verma Ravinder , Wang Jincheng , Xin Dazhuan , Lu Richard 
Published: November 2019

Abstract
Glioblastomas are malignant brain tumors that carry a poor prognosis. The tumor microenvironment has been identified as an important regulator of tumor growth and may represent a novel target for therapy. Transcriptional subtypes of glioma are a major source of heterogeneity of expression in gliomas. Gliomas are highly heterogeneous diseases and can be classified into different subtypes including proneural, classical and mesenchymal tumors. We hypothesized that different subtypes of glioma will have different microenvironmental composition and exhibit distinct responses to therapies. To understand whether gliomas induced by different oncogenic drivers affect microenvironment composition, we induced mouse gliomas using a PDGFB and dnp53 driver to model proneural glioma and HRasV12 and dnp53 to model mesenchymal glioma, respectively. We performed single cell transcriptomic profiling to characterize the tumor microenvironment in these glioma models. We found that in the PDGFB/dnp53 glioma model had a large microglia contribution with about 30% tumor-associated microglia. In contrast, the HRasV12/dnp53 glioma model had only sparse microenvironmental cells. In addition, microglia in each model displayed subtype-specific gene expression programs, with microglia in the HRasV12/dnp53 tumor model expressing increased antigen presenting genes while increased levels of osteopontin in the PDGFB/dnp53 tumor model. To determine the tumor-microenvironment interactions, we performed receptor-ligand analysis using CellPhoneDb to identify secretory ligands that support tumor cell growth in microenvironmental cells. We found that tumor-associated pericytes are an important source of growth factor ligands in both PDGFB/dnp53 and HRasV12/dnp53 glioma models. We are investigating the contribution of microglia and pericytes to tumor growth and survival through cell depletion and pharmacological inhibition and determining whether the differences in tumor microglia between the models affects sensitivity to therapies including immunotherapy. Understanding how tumor-intrinsic signaling modulates microenvironment niches and tumor-microenvironment communications aids rational design of combinations targeting the malignant brain tumors.
ACTR-68. FEASIBILITY STUDY OF THE EMULATE THERAPEUTICS™ VOYAGER SYSTEM IN PATIENTS WITH RECURRENT GLIOBLASTOMA (GBM)
Authors: Barkhoudarian Garni , Badruddoja Michael , Blondin Nicholas , Chen Ricky , Chowdhary Sajeel , Cobbs Charles , Dowling Anthony , Duic Paul , Paul Flores John , Fonkem Ekokobe , McClay Edward , Nabors Louis , Salacz Michael , Vaillant Brian , Kesari Santosh 
Published: November 2019

Abstract

BACKGROUND
The EMulate Therapeutics Voyager system is an investigational non-sterile, non-invasive, non-thermal, non-ionizing, portable, home-use medical device that uses a specific, localized ultra-low radio frequency energy (ulRFE®) cognate for the treatment of brain cancer.

METHODS
This ongoing, open-label, multi-center study (NAT-101) is being conducted in the US and Australia in patients with recurrent GBM. There are 3 treatment groups: 32 patients treated with Voyager alone, 43 patients treated with Voyager + Investigator’s choice of anti-cancer therapy, and 21 patients treated with Voyager+lomustine+/-bevacizumab. The objective of the study is to assess if the Voyager is a safe and feasible treatment for recurrent GBM. The primary outcome measure is safety, assessed by the incidence and evaluation of adverse events (AEs) associated with the Voyager. The secondary outcome measures are progression-free survival and overall survival.

RESULTS
Enrollment is closed, and long-term treatment and follow-up is ongoing. 96 patients were enrolled and treated. 82 patients reported at least one AE, and 18 AEs were assessed as device-related (mild-moderate; 12 headache, 2 vomiting, 1 nausea, 1 confusion, 1 insomnia, and 1 skin irritation). 31 patients reported at least one serious AE, and none were assessed as device-related. 33% of patients treated with Voyager alone and 36% of patients treated with Voyager + chemotherapy were progression-free after 6 months. 58% of patients treated with Voyager alone and 60% of patients treated with Voyager + chemotherapy remained alive after 6 months; median overall survival is 7 months (95% CI=4.4±14.3) in patients treated with Voyager alone and 10 months (95% CI=6.7±11.5) in patients treated with Voyager + chemotherapy.

CONCLUSIONS
The Voyager system appears to be safe and feasible for the treatment of recurrent GBM. Given that therapy is delivered non-invasively and no device-related serious adverse events were reported, further prospective study of the investigational device is planned.
TMIC-63. ENDOCAN BRIDGING THE GAP: TUMOR ENDOTHELIAL CELL SECRETOME AND THE VASCULATURE-PROXIMAL TUMOR EDGE
Authors: Bastola Soniya , Ghochani Yasmin , Pavlyukov Marat S , Ghosh Sadashib , Kurowsky Morgan , Kornblum Harley , Nakano Ichiro 
Published: November 2019

Abstract

BACKGROUND
Glioblastoma (GBM) is a highly invasive, angiogenic and therapeutically resistant primary brain tumor. It is impossible to completely resect the tumor, which subsequently leaves behind tumor “edge” that can act as seeds for recurrence. We recently reported the leading “edge” and tumor core have the presence of two distinct types of glioma stem-like cells (GSCs) that resemble proneural (PN) and mesenchymal (MES) subtypes, respectively. GSCs are enriched in perivascular niches, and vascular endothelial (VE) cells are known to provide paracrine factors, radioresistance properties to GSCs. Therapeutically, targeting GBM using an anti-angiogenic anti-VEGF inhibitor, Bevacizumab, did not aid in overall survival and instead resulted in aggressive MES phenotype. Hence, it is imperative to study this nexus in greater detail to develop novel targeted therapies for VE and GBM cells. The purpose of this study was to understand the molecular mechanisms emanating from VE cells that cause the invading “edge” to recur and determine if targeting these molecular cascades can provide therapeutic benefit.

RESULTS
Using unbiased approach to identify paracrine factors from GBM patient derived VE cells, we identified endocan, a vascular endothelial cell secreted molecule, as a pro-tumorigenic factor essential for neovascularization, radioresistance, and stemness of GBM edge tumor cells. Utilizing patient-derived and mouse glioblastoma sphere models and the corresponding intracranial tumor models, we demonstrate that endocan maintains the “edge”-located glioma stem cell signature and protects glioblastoma cells from radiation-induced differentiation and apoptosis. Mechanistically, we show that endocan is a novel ligand that interacts with PDGFRa and induce its phosphorylation, leading to phosphorylation of the downstream targets PI3K and MAPK in GBM.

CONCLUSIONS
Collectively, these findings demonstrate a novel signaling axis of endocan-PDGFRa in GBM that is activated by tumor endothelial cell and plays an essential role in glioma stem cells maintenance and radioresistance in tumor “edge”.
TMOD-01. CHARACTERIZATION OF PATIENT-DERIVED PRIMARY CELL LINES AND XENOGRAFTS FOR GLIOBLASTOMA
Authors: Kijima Noriyuki , Kanematsu Daisuke , Shofuda Tomoko , Nonaka Masahiro , Iwata Ryoichi , Fukai Junya , Inoue Akihiro , Sasayama Takashi , Tsuyuguchi Naohiro , Kawashima Toshiyuki , Higuchi Yuichiro , Suemizu Hiroshi , Mori Kanji , Kishima Haruhiko , Kanemura Yonehiro 
Published: November 2019

Abstract
Patient-derived primary cell culture and xenograft are essential tools for translational research for glioblastoma. However, characteristics of each patient derived cell line and xenograft is not extensively studied. In this study, we aim to analyze the characteristics of our glioblastoma patient-derived cell lines and xenografts based on cell surface markers and their differentiation patterns. We have established 20 glioblastoma primary cell culture lines by serum free medium containing EGF and bFGF and found that primary cell culture lines could be classified based on the expression of CD133 and CD44. Four cell lines had high expression of both CD133 and CD44. Eleven cell lines had high expression of only CD44, three cell lines had high expression of only CD133, two cell lines had low expression of both CD133 and CD44. In addition when we induce differentiation, these cell lines showed differentiation to both glial and neuronal differentiation, but differentiation patterns were different depending on each cell line. Four cell lines showed predominant neuronal differentiation and others showed predominant glial differentiation. We next investigated in vivo characteristics of glioblastoma patient derived xenografts from these established cell lines. We have injected these cell lines into NOD/Shi-scid IL2Rγ KO mouse and histopathologically analyzed characteristics of xenografts. Each xenograft well recapitulated histological features of original patients’ tumors and tumor cells remarkably invade through subventricular zone. These results suggest that glioblastoma patient derived primary cell lines and xenografts have different characteristics of cell surface marker expressions and differentiation patterns, thus can classify these cell lines depending on cell surface marker expressions and differentiation patterns. Further analysis is needed to examine the biological importance of the differences in cell surface marker expressions and differentiation patterns.