bluuebunny/crossref_metadata_2025_split huggingface dataset:
GENE-48. ANALYSIS OF HUMAN BRAIN TISSUE TRANSCRIPTOME TO IDENTIFY RISK GENES AND ALTERED MOLECULAR PATHWAYS IN GLIOMA-RELATED SEIZURES
Authors: Feyissa Anteneh , Carrano Anna , Wang Xue , Allen Mariet , Ertekin-Taner Nilufer , Rosenfeld Steven , Guerrero-Cazares Hugo , Quinones-Hinojosa Alfredo 
Published: November 2019

Abstract

OBJECTIVE
Our goal is to identify new pathways perturbed in and which may lead to GRS.

METHODS
We collected brain transcriptome levels from healthy controls (n=5), patients with GRS (n=9), glioma without seizures (non-GRS, n=8), and idiopathic temporal lobe epilepsy (iTLE, n=7) using Illumina-based poly-A capture high-throughput RNA sequencing approach. Differential gene expression analysis was conducted to ascertain expression differences between the four groups. We identified molecular pathways enriched for differentially expressed genes (DEG) using Ingenuity Pathway Analysis. DEGs were defined as those with log2 fold change ≥ 2 and q-value < 0.01 when compared to GRS.

RESULTS
Principal component analysis revealed that diagnostic grouping was the main determinant of the transcriptome variance. We identified 212 DEGs in the GRS vs. non-GRS analysis. Among these, 108 genes were up-regulated and 104 genes were down-regulated. Among the genes that were down‐regulated, there was significant enrichment for those involved in acute phase response signaling and immune cell trafficking (e.g. H19, BMP5, CXCL8). Compared to iTLE samples, there were 1015 DEGs in the GRS samples. Among these 877 genes were up-regulated and 138 genes were down-regulated. There was significant enrichment for genes involved in cell-to-cell signaling among those that were either uniquely up‐regulated (e.g. NRK, RGS10, SLC4A4, and SELPLG) or down‐regulated in the GRS samples (e.g. SLC9A3 –Na+/H+ exchanger; SLC5A5-sodium-glucose co-transporter family). Further, two of the most down-regulated genes in samples with GRS, SCLC17A6- vesicular glutamate transporter 2 and FOSB, have previously been shown to be involved in glutamatergic transmission.

CONCLUSIONS
Our findings suggest that inflammation-related processes and alterations in cell-to cell signaling may underlie the pathogenesis of GRS. Our results also provide support for perturbations in glutamatergic transmission in GRS. Our findings require replication in larger human cohorts and functional experiments to explore the function of the genes perturbed in GRS.
GENE-51. ROLE OF TUMOR ENDOTHELIAL MARKER 8 (TEM8) IN PRIMARY AND RECURRENT GLIOBLASTOMA.
Authors: Kundu Paramita , Jain Ruchi , Arimappamagan Arivazhagan , Santosh Vani , Kondaiah Paturu 
Published: November 2019

Abstract
Glioblastoma (GBM) is the most common primary malignant tumor of the adult central nervous system. It is highly invasive and almost inevitably recurs; leading to a median survival of 15 months. The recurrent tumor in most cases is radiotherapy and chemotherapy-resistant, making them quite challenging to treat. Several studies have elucidated key driver genes and molecular pathways involved in Gliomagenesis, but genes/pathways that might be involved in aiding relapse are not well elucidated. Interestingly, chemotherapy with Temozolomide and γ-irradiation have been documented to alter the DNA methylome of cells in vitro. A probable hypothesis could be that following surgical resection, therapy alters the epigenome of residual cancer cells giving rise to aggressively resistant recurrent tumors. To examine this possibility, 24 GBM biopsies (11 primary and 13 recurrent GBMs) were subjected to Methylation Bead Array to assess differential methylation of genes in recurrent GBM compared to primary tumors. This was correlated with RNA-seq data for recurrent tumors in TCGA database. A total of 1751 differentially methylated regions (DMRs) were identified, among which 205 differentially methylated genes (74 hypomethylated and 131 hypermethylated) were found to correlate with methylation and RNA-sequencing data of recurrent tumors in TCGA. Among these genes, ANTXR1/TEM8 (Tumor Endothelial Marker 8) was found to be overexpressed in recurrent tumors compared to primary tumors at both transcript and protein levels using RT-PCR and immunohistochemistry, respectively. When overexpressed in Glioma cell lines, TEM8 was found to upregulate phospho-GSK3β, phospho-AKT and lead to β-catenin translocation to the nucleus resulting in activation of Wnt signaling pathway. TEM8 overexpressing cells showed mild enhancement in proliferation and resistance to Temozolomide, Cisplatin and 5-fluoroUracil. Stem cells markers like Oct4 and Nanog are also upregulated. In conclusion, TEM8 may be involved in GBM recurrence and may have a role in conferring chemo- and radioresistance.
GENE-53. IDENTIFICATION OF EPITHELIAL MEMBRANE PROTEIN 2 (EMP2) AS A MOLECULAR MARKER AND THERAPEUTIC TARGET IN MENINGIOMA
Authors: Patel Kunal , Duong Courtney , Sun Matthew , Romiyo Prasanth , Kejriwal Sameer , Chan Ann , Gordon Lynn , Wadehra Madhuri , Yang Isaac 
Published: November 2019

Abstract

BACKGROUND
Intracranial meningiomas have been associated with a heterogenous set of genetic and molecular alterations. Despite these genetic associations, targeted therapies have been unable to increase survival in recurrent or residual meningiomas. There is a need for identification of therapeutic targets in meningioma.

MATERIALS & METHODS
Normal brain tissue from routine autopsy and tumor specimens from patients undergoing primary surgical resection of meningioma were analyzed. Pathologic diagnosis and grade were identified. Samples were stained with anti-EMP2 antisera and visualized with DAB (3,3’-Diaminobenzidine). Western blot analysis was carried out

RESULTS
In 17 patients with meningioma, there was statistically significant EMP2 staining in fresh brain tumor samples. EMP2 expression was confirmed and quantified with western blot which demonstrated significant positive expressivity. There were 12 grade I, 4 grade II, and 1 grade III meningiomas in our dataset and a significant trend towards increased EMP2 expression with higher grade. EMP2 expression was not identified in normal brain tissue samples from different locations including gray matter, white matter, and meninges in 3 control patients.

CONCLUSIONS
EMP2 is a protein associated with cell migration, invasion, and angiogenesis not identified in normal brain tissue but found in meningioma. EMP2 expression may be associated with increased tumor invasion and is a potential therapeutic target for residual or recurrent meningioma.
GENE-59. NOT ALL p53 MUTATIONS ARE CREATED EQUAL: A MURINE ASTROCYTE MODEL FOR HIGH-THROUGHPUT FUNCTIONAL ASSESSMENT OF p53 MISSENSE MUTATIONS
Authors: Rockwell Nathan , Staller Max , Cannella Maria , Cohen Barak , Rubin Joshua 
Published: November 2019

Abstract
The tumor suppressor TP53 (p53) is the most commonly mutated gene in cancer and among the most frequently mutated genes in glioblastoma (GBM). The majority of p53 mutations in GBM are missense mutations in the DNA binding domain that lead to the production of full length mutant p53 protein. In addition to the complete loss of tumor suppressor function, these mutations have gain-of-function (GOF) properties either through attenuation of wild-type function or neomorphic functions. The variability in GOF mutations results in heterogeneity in cancer phenotypes between mutants that remain poorly understood. Here, we developed a murine astrocyte model to functionally assess a library of p53 mutants in parallel. Primary astrocytes were isolated from postnatal day one pups possessing a single copy of wild-type p53 flanked by loxP sites (TRP53f/-). We then built a library of 17 individual alleles of recurring mutations in GBM with flanking loxP sites. When co-transfected into the mouse astrocytes with a plasmid expressing Cre recombinase, the endogenous WT p53 was excised and replaced with a single copy of the mutant allele. In this way, all astrocytes expressed a single copy of mutant p53 from the endogenous p53 locus. As the mutant p53 cells expanded, aliquots of cells were extracted for targeted genomic sequencing of the p53 allele. Comparing the allelic frequencies of each mutant overtime revealed a wide distribution of growth rates between mutants. To validate the screen results, wildtype astrocytes were transduced with mutant p53-IRES-eGFP retrovirus to overexpress one of three mutations with divergent growth phenotypes. As observed in the initial screen, equivalent overexpression of the different p53 mutants was sufficient to induce significant differences in growth phenotype, with astrocytes expressing the Y217C growing the fastest, R172H second, and Y202C growing the slowest. Ongoing studies are evaluating mutation-specific p53 binding partners and transcriptional outputs.
HOUT-15. IDENTIFICATION AND CHARACTERIZATION OF CARDIAC EVENT ABNORMALITIES IN PATIENTS WITH CRANIOPHARYNGIOMA
Authors: Seligman Christa , Harrison Rebecca , Hassan Saamir , Wu Jimin , DeGroot John , Raza Shaan 
Published: November 2019

Abstract

BACKGROUND
Craniopharyngiomas (CP) are frequently associated with a malignant clinical trajectory despite their benign histology. This population frequently has endocrinopathies and autonomic dysfunction due to tumour location, which may influence cardiac function and long term health outcome. In this study, we evaluated for clinical and paraclinical cardiac abnormalities in adult and pediatric patients with craniopharyngioma.

METHODS
We retrospectively identified patients in our neurosurgery database with a diagnosis of craniopharyngioma that received neurosurgery at MD Anderson Cancer Center. We queried the medical record for demographic and disease-related information, as well as clinical information regarding cardiac risk factors. Perioperative electrocardiograms (EKGs) were analyzed where available.

RESULTS
We identified 56 patients with craniopharyngioma, 27 (48.2%) of which were female. Average age was 39 years, and all patients had undergone subtotal (49.1%), gross total (32.7%), or near gross total (18.2%) resection. Over half (53.6%) had undergone radiation, none had received systemic therapy, and 1 (1.8%) intra-cystic chemotherapy. The majority had adamantanomatous-type histology (83%) and the remainder papillary (17%). At diagnosis, average BMI was elevated at 30.98. Hypertension (30.4%), diabetes mellitus (32.1%), and thyroid dysfunction (80%), were found in this cohort. Nearly a quarter (23.2%) were on statin therapy for dyslipidemia. Stimulant (14.3%) and neuropleptic (3.6%) use were also identified. Of patients with perioperative EKG performed (N= 39), 30 were available for review. Of these, patients were identified with abnormal rate (N=9, 30.0%), PR interval (N=2, 6.7%), QRS interval (N=4, 13.3%), and QTc interval (N=1, 3.3%). Some patients presented with a history of heart palpitations (1.8%) and syncopal episodes (3.6%), but not chest pain.

CONCLUSION
This analysis demonstrates frequent vascular and cardiac risk factors in patients with craniopharyngioma. We advocate for increased awareness of cardiac health in this young population. Further prospective evaluation is warranted to better understand cardiac health in this patient group.
IMMU-07. CELLULAR IMMUNOTHERAPY TO OVERCOME TEMOZOLOMIDE INDUCED T CELL EXHAUSTION IN GLIOBLASTOMA
Authors: Karachi Aida , Dastmalchi Farhad , O’Malley Ashley , Saia Megan , Mitchell Duane , Rahman Maryam 
Published: November 2019

Abstract

INTRODUCTION
We have previously demonstrated that standard dose (SD) temozolomide results in T cell exhaustion in glioblastoma. In this study, we hypothesized that cellular immunotherapies will prevent T cell exhaustion. We tested temozolomide treatment with adoptive T cell transfer alone, dendritic cell (DC) vaccines alone and T cell transfer in combination with DC vaccines.

METHOD
GL-261-gp100 tumor-bearing mice were treated with SD (50 mg/kg for 5 days) or metronomic dose (MD) (25 mg/kg for 10 days) temozolomide. CD3+ T cells were isolated from Pmel mice and infused intravenously. Antigen-specific DC vaccines (gp-100) were given intradermally at the concentration of 50×104. Peripheral blood T cell populations were evaluated by flow cytometry. IFN-gamma secretion was measured for evaluation of T cells function. Survival was compared between groups.

RESULTS
Survival analysis demonstrated that naïve T cell transfer alone and DC vaccine alone add no survival benefit to temozolomide treatment for tumor-bearing animals. There were no significant differences in the expression of exhaustion markers of Tim-3 and Lag-3 on T cells of animals that received a combination of activated T cells and DC vaccines in the context of temozolomide therapy compared to the animals that just received temozolomide. Combination of activated T cell transfer and DC vaccines did not increase IFN-gamma secretion from T cells compared to temozolomide treated animals. Combination of naïve T cell transfer and two DC vaccines increased IFN-gamma secretion from T cells of GL-261 gp100 tumor-bearing animals. However, naïve T cell transfer and two DC vaccines in the context of temozolomide was not potent enough to extend the survival of these tumor-bearing animals.

CONCLUSION
Combinatorial treatment with naïve antigen-specific T cells and three dendritic cell vaccine boosters in the context of temozolomide is a promising approach to preserve T cell function and avoid T cell exhaustion.
IMMU-11. SPATIOTEMPORAL IMMUNOGENOMIC ANALYSIS OF THE T-CELL REPERTOIRE IN IDH-MUTANT LOWER GRADE GLIOMAS
Authors: Zhang Michael , Hilz Stephanie , Martin Michael , Hong Chibo , Yu Yao , Bollam Saumya , Grimmer Matthew , Looney Timothy , Lowman Geoffrey , Ganpule Gauri , Phillips Joanna , Shai Anny , Chang Susan , Clarke Jennifer , Taylor Jennie , Butowski Nicholas , Ann Oberheim-Bush Nancy , Berger Mitchel , Aghi Manish , Hervey-Jumper Shawn , McDermott Mike , Theodosopoulos Philip , Okada Hideho , Costello Joseph 
Published: November 2019

Abstract
The design and evaluation of immunotherapies in IDH-mutant lower grade gliomas (LGG) is hindered by a poor understanding of the LGG T-cell repertoire. We present data on the temporal evolution, intratumoral spatial distribution, and prognostic value of the T-cell repertoire in IDH-mutant LGGs. We performed immunogenomic profiling using T-cell receptor beta-chain sequencing of 163 glioma and peripheral blood samples from 33 immunotherapy-naive glioma patients (22 astrocytomas, 11 oligodendrogliomas). T-cell repertoire evolution was analyzed in a subset of 26 patients (69 samples) with matched primary (WHO grade II) and recurrent (WHO grade II-IV) glioma samples. T-cell repertoire diversity was defined as the number of unique T-cell clonotypes by V-gene, J-gene, and CDR3 nucleotide sequences. Malignant transformed (Grade III or IV) recurrent gliomas demonstrated increased T-cell repertoire diversity compared to their patient-matched primary tumors (p=0.0023), but grade II recurrences did not show the same increased diversity (p=0.26). This increase in T-cell repertoire diversity was greater in patients who underwent transformation in the context of TMZ-associated hypermutation compared to spontaneously transformed counterparts (p=0.035). In grade II primary astrocytomas (n=17), T-cell repertoire diversity above the median (186 unique T-cell clonotypes per sample) was associated with worse transformation-free (HR=4.2, p=0.045) and overall survival (HR=6.4, p=0.025). Next, we evaluated intratumoral immune heterogeneity in 7 patients by sampling from up to 10 distinct and maximally-separated intratumoral sites per LGG (64 samples). Eighty-two to 96% of unique clonotypes within a given tumor were present only within a single sampled site. Despite this heterogeneity, six LGG patients harbored T-cell clonotypes present tumor-wide across all sampled sites within a given tumor. Ten of 24 (42%) tumor-wide T-cell clonotypes were enriched in the glioma compared to matched peripheral blood, suggesting glioma-specificity. Taken together, T-cell receptor profiling in LGGs may have utility both as a prognostic biomarker and to identify glioma-specific T-cells.
IMMU-12. IL13Ra2-CAR T CELLS STIMULATE ENDOGENOUS IMMUNE RESPONSES AGAINST MURINE GLIOBLASTOMAS
Authors: Alizadeh Darya , Wong Robyn , Pecoraro Joseph , Yang Xin , Forman Stephen , Brown Christine E 
Published: November 2019

Abstract
Malignant gliomas (MG) are one of the deadliest cancers with very limited therapeutic options. Chimeric antigen receptor (CAR)-T cell therapy has emerged as a powerful strategy for B-cell malignancies and may offer new opportunities to improve outcomes for patients with MGs. Our team is clinically evaluating IL13Rα2-targeted CAR-T cells for the treatment of recurrent IL13Rα2-positive MGs [NCT02208362]. While this trial is ongoing, we have previously reported that one patient with recurrent multifocal glioblastoma achieved a complete response post-IL13Rα2-CAR-T therapy despite the non-uniform expression of IL13Rα2 on the tumor. The therapeutic response against IL13Rα2-negative cells suggests CAR-T cells may stimulate endogenous immune responses. To study the interplay between CAR-T cells and host immune subsets, we have established a syngeneic immunocompetent glioma model, which recapitulates the tumor microenvironment (TME) of patients. Murine IL13Rα2-CAR-T cells mediate potent antitumor activity against IL13Rα2-engineered KR158, a highly invasive murine glioma model. Interestingly, mice “cured” from CAR-T therapy, after rechallenge, can successfully reject the tumors. Furthermore, we demonstrate comparable response rate in mice bearing gliomas with mixed antigen expression (50%IL13Rα2+/50%IL13Rα2-) vs 100% IL13Rα2+. Characterization of the TME post-CAR-T therapy indicates activation of endogenous cytotoxic CD8 T and myeloid cells, and decrease in the frequency of T regulatory cells. Further analyses reveal that tumor-associated macrophages (TAMs) may be reprogrammed during CAR-T therapy to exhibit tumoricidal activity and may promote the activation of endogenous T cells (CD4/CD8 T cells) resulting in enhanced antitumor activity. Current studies are focusing on the characterization of host immune cells to identify the mechanisms involved in induction of host immune responses mediated by CAR-T cell therapy. Our data thus strongly suggest that CAR-T therapy has the potential to reshape the glioma microenvironment creating a context permissible to elicit effective endogenous antitumor immunity.
IMMU-21. SEQUENTIAL TWO-RECEPTOR PRIMING CAR SYSTEM TO OVERCOME HETEROGENEOUS ANTIGEN EXPRESSION
Authors: Watchmaker Payal , Choe Joseph , Carrera Diego , Gilbert Ryan , Yu Wei , Downey Kira , Roybal Kole , Lim Wendell , Okada Hideho 
Published: November 2019

Abstract
Heterogeneous expression of target antigens allows tumor escape from chimeric antigen receptor-transduced T-cell (CART) therapy targeting a single antigen. While epidermal growth factor receptor (EGFR)vIII represents a glioblastoma (GBM)-specific antigen, its expression is heterogeneous within the tumor. On the other hand, most other antigens expressed more uniformly in GBMs are non-mutated, glioma-associated antigens (GAAs), such as EphA2. Although these GAAs are not expressed in the normal brain, they are expressed at low levels in other normal organs. As a way to safely target GAAs in the tumor without attacking normal cells expressing the same GAAs outside of the brain, we adapted a novel synthetic Notch (synNotch) receptor system, and established a “prime and kill” sequential two-receptor CAR circuit: the first is a transcriptional CAR against EGFRvIII, and the second is a CAR against a GAA (e.g. EphA2). When the first CAR binds to EGFRvIII, it induces the expression of the second CAR against GAA. While the first CAR does not trigger the cytotoxic function itself, the second CAR mediates the cytotoxicity upon recognition of the target GAA. We validated this system in vitro using the mixture of U87 GBM cells and those transduced with EGFRvIII. SynNotch CART effectively lysed both EGFRvIII+ and EGFRvIII-negative U87 cells when they are mixed, but never lysed EGFRvIII-negative cells in the absence of EGFRvIII+ cells. SynNotch CART cells exhibited precise local effect in vivo, sparing EGFRvIII-negative subcutaneous tumor while efficiently clearing intracranial EGFRvIII heterogeneous tumor. In the orthotopic GBM6 model, which is a patient-derived xenograft with heterogeneous expression of EGFRvIII, intravenous infusion of synNotch CART resulted in long-term (over 50 days) survival and eradication of the heterogeneous tumor in 6 of 6 mice, while the conventional anti-EGFRvIII CART failed to do so. These data provide a strong basis for developing synNotch CART therapy for GBM.
IMMU-35. COMPLEMENT SYSTEM AND GLIOBLASTOMA: AN INTRICATE RELATIONSHIP
Authors: Mittal Sandeep , Sengupta Shayak , Khan Sabbir , McGee Kain , Alfaro-Munoz Kristin , Balasubramaniyan Veerakumar , DeGroot John 
Published: November 2019

Abstract
The complement system is a vital part of the innate immune system which plays a critical role in immune surveillance and inflammatory processes. Malignant and host cells express various complement inhibitory proteins on their surface to protect against complement mediated cytotoxicity. Imbalanced complement activation triggers inflammation and alters the tumor microenvironment. Complement activation has been shown to induce proliferation and migration of breast, ovarian and lung cancer cells. At this time, the expression and functional role of the complement cascade in glioblastoma (GBM) remain elusive. Here, we investigated the role of complement proteins and their receptor expression in human primary glioma stem-like cells (GSCs) and human GBM tissues. Western blot data demonstrated a high level of expression of central complement components and their receptors in GSCs. RT-PCR data further confirmed the high expression of complement genes which was similar or higher to normal human astrocytes (HA), a cell with high baseline expression levels of complement genes. Flow cytometry analysis revealed that almost 95% of GSCs expressed the anaphylatoxin complement receptors C3aR and C5aR on their cell surfaces which was consistent with our immunohistochemistry analysis of freshly resected GBM tissues. Furthermore, anaphylatoxin C5a exposure increased the proliferation of a subgroup of GSCs while reduced in another subset. Interestingly, C5a exposure was found to increase the expression of various pro-inflammatory markers in GSCs with reduced proliferation. Fluorescence-activated cell sorting (FACS) analysis of freshly isolated human GBM tissue revealed predominant expression of C5aR on cancer cells (CD11b-/CD45- cells) rather than on immune cells. RT-PCR analysis also demonstrated high expression levels of complement genes with concomitant decrease in complement inhibitory genes in human GBM tissue. Evaluation of the differential role of the complement system in GSCs along with their role in in vivo glioma models is ongoing.