bluuebunny/crossref_metadata_2025_split huggingface dataset:
CBIO-11. NOVEL THERAPY TO TARGET PR-RECURRENT GLIOMA
Authors: Rahman Masum , Olson Ian E , Saber Rehan , Zhang Jibo , Carlstrom Lucas P , Sisi Chen , Rajani Karishma , Brown Desmond , Parney Ian , Sarkaria Jann , Burns Terry C 
Published: December 2020

Abstract

BACKGROUND
Glioblastoma is a fatal infiltrative primary brain tumor, and standard care includes maximal safe surgical resection followed by radiation and Temozolomide (TMZ). Therapy-resistant residual cells persist in a latent state a long time before inevitable recurrence. Conventional radiation and Temozolomide (TMZ) treatment cause oxidative stress and DNA damage resulting senescent-like state of cell-cycle arrest. However, increasing evidence demonstrates escaping senescence leads to tumor recurrence. Thus, the ablation of senescent tumor cells after chemoradiation may be an avenue to limit tumor recurrence.

METHODS
100uM TMZ for 7days or 10-20Gy radiation (cesium gamma radiator) was used for senescence induction in human glioblastoma in vitro and confirmed by SA-Beta gal staining and PCR. Replication arrest assessed by automated quantification of cellular confluence (Thermo Scientific Series 8000 WJ Incubator). We evaluated the IC50 for several senolytics targeting multiple SCAPs, including Dasatinib, Quercetin, AMG-232, Fisetin, Onalespib, Navitoclax, and A1331852, and in senescent vs. proliferating cells.

RESULTS
Among the senolytic tested, the Bcl-XL inhibitors A1331852 and Navitoclax both shown senolytic effect by selectively killing radiated, senescent tumor cells at lower concentrations as compared to 0Gy treated non-senescent cells. Across 12 GBM cell lines, IC50 for senescent cells was 6–500 times lower than non-senescent GBM(p&lt; 0.005). Such differential sensitivity to Bcl-XL inhibition after radiation has also observed by BCL-XL knockdown in radiated glioma.

CONCLUSION
These findings suggest the potential to harness radiation-induced biology to ablate surviving quiescent cells and demonstrate Bcl-XL dependency as a potential vulnerability of surviving tumor cells after exposure to chemoradiation.
CBIO-15. MDM2 INHIBITOR SYNERGY WITH BCL-XL INHIBITION FOR p53 WILD TYPE GLIOBLASTOMA
Authors: Rahman Masum , Olson Ian E , Saber Rehan , Carlstrom Lucas P , Jhang Jibo , Brown Desmond , Rajani Karishma , Sarkaria Jann , Parney Ian , Burns Terry C 
Published: December 2020

Abstract

BACKGROUND
Glioblastoma (GBM) is an infiltrative, uniformly fatal brain tumor, treated with surgery, radiation, and Temozolomide (TMZ). Chemoradiation induces a senescent-like phenotype, which contributes to disease recurrence. We recently found that, radiated GBM cells can be eliminated by inhibition of BCL-XL. However, it remains unknown whether p53 is involved in this process and whether the elimination of senescent cells by BCL-XL inhibition could be augmented by MDM2 inhibition, a negative p53 regulator.

METHODS
p53-mutant (GBM6/GBM123) and p53-WT (GBM39/GBM76) human GBM cells were treated with 5Gy or TMZ following 48 hours of MDM2 inhibitor (AMG232) or vehicle treatment and maintained for seven days to establish a senescent-like phenotype. We evaluated the IC50 for BCL-XL inhibitor (A1331852) in radiated vs. non-radiated cells with or without MDM2 inhibitor pre-treatment.

RESULTS
MDM2-inhibitor treatment prior to radiation increased the expression of p21 and lead to increased cell death when combined with BCL-XL inhibition in p53-WT GBM cells. IC50 of BCL-XL inhibitor after prior MDM2 pretreatment and radiation in GBM76 was 4.5□M compared to 33.5□M, 18.1□M, and 32.3□M in vehicle without radiation, vehicle with radiation, and MDM2 inhibitor-alone treatment groups, respectively(p=0.0036). The IC50 of BCL-XL inhibitor without MDM2-inhibition in non-irradiated and radiated, as well as pre-administration of MDM2 inhibitor in non-irradiated and radiated GBM39 cells was 5618nM, 16117nM, 3926nM and 276.5nM, respectively(p=0.0003). Conversely, MDM2 co-inhibition with BCL-XL did not lead to increased rates of cell death in p53-mutant cell(p&gt;0.05).

CONCLUSION
We previously identified that BCL-XL inhibition promotes cell death in senescent GBM cells. We build upon that work, demonstrating the increased rates of cell death can be augmented by MDM2 inhibition, but only in p53-WT cells. These findings highlight a novel therapeutic target for treating latent GBM tumors prior to recurrence, with the additional of MDM2 inhibition greatly increasing the efficacy of BCL-XL targeting agents.
CBIO-17. IDENTIFYING A NETWORK OF ESSENTIAL & TUMORIGENIC GENES IN GLIOBLASTOMA USING WHOLE-GENOME CRISPR Cas9 SCREENING
Authors: Baisiwala Shivani , Saathoff Miranda , Dmello Crismita , Shireman Jack , Chen Li , Park Cheol , Awah Chidibere , Goel Chirag , Budhiraja Shreya , Hardiman Clare , Sonabend Adam , Ahmed Atique 
Published: December 2020

Abstract
GBM is the most common primary malignant brain tumor in adults, with a 100% recurrence rate and a median survival of 21 months. As such, advances in therapy are desperately needed. Genomic approaches have shown that GBM has high intra-tumoral heterogeneity. However, a comprehensive understanding of determinants of growth is required to identify new therapeutic targets. CRISPR-Cas9 screening technology has enabled whole-genome screens that allow objective identification of genes governing specific phenotypes. Here, we performed a genome-wide CRISPR knockout screen in H4 human glioma cells to identify genes that drive proliferation. Our screen identified ~150 novel essential growth genes. From this list, we identified 5 genes that were previously unstudied, show significant elevations in expression at the RNA and protein levels (p&lt; 0.05), and show significant survival benefit in patient datasets (p&lt; 0.05) – PSMB3, CHCHD4, THOC1, SPDYE5, HSPA1. Our validation experiments showed that knocking out these genes resulted in cell death in multiple GBM patient-derived xenograft (PDX) lines. In addition, animals with knockout cells implanted demonstrated extended survival (p&lt; 0.01). Furthermore, overexpression of these genes in a normal neural stem cell line resulted in transformation to a cancer phenotype, as evidenced by sphere formation in a soft agar assay (p&lt; 0.01). Further investigation of one of these genes, PSMB3, which is a subunit of the proteasome, showed that ubiquitinated proteins were significantly increased after PSMB3 knockdown, suggesting that disruption of the proteasome system was the likely cause of cell death. We performed a ubiquitin immunoprecipitation (IP) to identify which genes were being uniquely ubiquitinated in GBM. Results showed pathways involving retinoblastoma genes, DNA repair genes, and DNA replication. Together, this data suggests that both our CRISPR screens and our ubiquitin IP have yielded promising and novel therapeutic targets for GBM, a disease desperately in need of new strategies.
COVD-22. COVID-19+ GLIOMA PATIENT CARE: LESSONS FROM A 5-PATIENT CASE SERIES
Authors: Daher Ahmad 
Published: December 2020

Abstract
Glioma patients, like other cancer patients, are at an increased risk of COVID-19 infections, but there are no specific guidelines on how their care should be modified during this pandemic. The challenge to develop such guidelines is largely related to the limited number of reported cases and lack of studies on this particular patient population. We present a 5-patient case series of glioma, detailing their baseline characteristics, treatment courses, lab abnormalities, and the changes made to their care after they developed COVID-19. The median age of the patient population was 66 years. All patients had IDH-wild type glioma (3 Grade IV, 1 Grade III, and 1 Grade II) and all of whom had received temozolomide chemotherapy shortly before COVID-19 diagnosis (median = 22 days). Three patients presented with mild non-respiratory symptoms requiring hospitalization to two of them, and adjuvant Temozolomide chemotherapy was held in all. One patient developed severe symptoms of shortness of breath requiring ICU-stay and expired eight days later. One patient was asymptomatic, tested positive during a routine pre-chemotherapy screening, and initiation of temozolomide was delayed by two weeks after a negative repeat test. All four symptomatic patients were rehabilitation facility residents. The most common lab abnormality was lymphopenia seen in 4/5 patients. Other abnormalities seen included elevated ferretin/total bilirubin/CRP/LDH/procalcitonin/D-dimer, thrombocytopenia/leukopenia, and low sodium/vitamin D. Chest x-ray findings were normal in 3/5 patients and showed ground glass opacities in 1 patient. COVID-19 screening during different phases of glioma therapy is recommended. Therapy interruptions or shortening duration of treatment particularly of temozolomide given its risk on lymphopenia may be needed. lymphopenia thresholds, MGMT promoter methylation status, and residence in rehabilitation facilities may help stratify glioma patient COVID-19 risks further. Patients and their family will need to be involved in therapies’ risk:benefit discussions during this pandemic.
CSIG-11. TARGETING PD-L1 IN GLIOBLASTOMA USING NANOPARTICLE-BASED GENE EDITING
Authors: Tran An , Fierro Javier , Dou Huanyu 
Published: December 2020

Abstract
Glioblastoma multiforme (GBM) is an astrocyte derived brain tumor with very poor prognosis, usually with a less than one year survival rate. Immunotherapy has shown promising therapeutic potentials in research and clinical application, however, GBM associated immunosuppressive microenvironment creates a significant barrier for effective anti-GBM immune responses. The immune checkpoint PD-1/PD-L1 pathways play a critical role in tumor-induced immunosupression to evade immune surveillance. Gene-editing tools targeting PD-1/PD-L1 pathway have gained increased research attention, however the major challenge is how to effectively deliver gene-editing tools without causing adverse effects for clinical translation. We have developed a nanoparticle (NP) delivery system from a low molecular weight PEI lipid shell and a PLGA core that can package PD-L1 gRNA-CRISPR/Cas9 plasmid to transfect human U87 glioma cells overexpressing PD-L1. PD-L1 gRNA-CRISPR/Cas9 plasmid is constructed by inserting single guide targeting PD-L1 sequence into GFP CRISPR/Cas9 plasmid for visualizing transfection efficacy. NP is labelled with Rhodamine 6G to monitor cellular uptake and trafficking. Fluorescence microscopy shows human U87 glioma cells can quickly uptake PD-L1 GFP-CRISPR/Cas9 plasmid-NPs within 2 hours as indicated by the Rhodamine 6G. GFP expression was obtained after 48 hours of transfection and maintained up to 7 days without causing toxicity. Western blot analysis confirmed successful knockdown of PD-L1 in U87 cells. These findings reveal that NPs made by a cationic branched PEI lipid shell and a PLGA core are non-toxic and efficient in delivering CRISPR/Cas9 system to U87 cells. Editing of pathological gene in human glioma cells with PD-L1 GFP-CRISPR/Cas9 plasmid using NPs as a delivery system may provide a novel immunotherapy platform to treat GBM.
CSIG-14. COMBINING THE GLIOBLASTOMA CELL MEMBRANE-PERMEABILIZING EFFECT OF TUMOR TREATING FIELDS (TTFIELDS) WITH WITHAFERIN A (AND OTHER) CHEMOTHERAPY
Authors: Chang Edwin , Patel Chirag , Young Caroline , Flores Thomas , Zeng Yi , Joubert Lydia , Arami Hamed , Natarajan Arutselvan , Sinclair Robert , Gambhir Sanjiv 
Published: December 2020

Abstract

BACKGROUND
Efforts are underway to uncover novel, unorthodox therapies against glioblastoma (GBM). Tumor treating fields (TTFields) disrupt mitotic spindle formation and inhibits tumor growth. Combining TTFields with Withaferin A and other therapeutics, synergistically inhibited proliferation. We describe relevant mechanisms.

METHODS
Human and murine GBM cells (GBM2, GBM39, U87-MG, KR158B) were isolated from primary tumors. Cells were engineered to stably express firefly luciferase (fLuc). Proliferation was assessed by bioluminescence imaging (using D-Luciferin as a substrate for fLuc) or cell counting. Dextran-FITC binding and scanning electron microscopy (SEM) studies were used to probe effects on cellular membranes.

RESULTS
TTFields (200 kHz, 4 V/cm) significantly inhibited growth of cells (n=3/time point, p≤0.02; 2-way ANOVA, no TTFields vs. TTFields). Combination of Withaferin A or other chemotherapeutics with TTFields significantly inhibited growth of glioma cells synergistically beyond that of Withaferin A or TTFields alone (p&lt; 0.01, at least n=3 experiments). Bioluminescence imaging suggested alterations in membrane configuration when cancer cells were exposed to TTFields. This was validated with observations of greater fluorescence of membrane-associating Dextran-FITC to U87-MG cells that were subjected to TTFields (p&lt; 0.01, 2-way ANOVA, TTFields vs. no TTFields, n=3 experiments). SEM revealed significantly greater and larger number of holes on the membrane surface of TTFields-exposed U87-MG cancer cells (53.5±19.1 holes per field of view and mean size=240.6±91.7 nm2) compared to unexposed cells (23.9±11.0 holes per field of view and mean size=129.8±31.9 nm2, p&lt; 0.005: TTFields exposed vs. non-exposed, n=3 samples, univariate Mann-Whitney test).

CONCLUSION
The findings suggest a novel combinatorial approach to treat GBM in a manner that is likely better than single treatment (drug or TTFields) alone and that is synergistic. Synergy is achieved through TTFields inducing increased permeability on membranes thus conferring greater accessibility to drug. Such a strategy is thus a promising candidate for future clinical translation in glioblastoma.
CSIG-20. L3MBTL3 SUPPRESSES MEDULLOBLASTOMA TUMORIGENESIS THROUGH MODULATION OF THE NOTCH/RBPJ SIGNALING PATHWAY
Authors: Zhang Honglai , Xu Tao , Peabody Claire , Fernández Ester Calvo , Budhathoki Rashmi , Huang Philip Chi-En , Hughes Elizabeth D , Saunders Thomas L , Kuick Rork , Magnuson Brian , Camelo-Piragua Sandra , Rual Jean-François 
Published: December 2020

Abstract
The NOTCH/RBPJ pathway governs cell proliferation in many biological contexts, including SHH and Group#3medulloblastoma (MB) tumorigenesis. Using our proteomic platform, we discovered an interaction between RBPJ, a key co-factor of NOTCH for the modulation of the NOTCH/RBPJ signaling pathway, and L3MBTL3, a methyllysine reader. L3MBTL3 is recruited by RBPJ on chromatin at the enhancers of NOTCH/RBPJ target genes to repress their expression. Deletions of the L3MBTL3 locus are observed in patients with WNT and Group#3 MB and expression of L3MBTL3 in the SHH MB-derived cell DAOY inhibits cell growth, suggesting a putative tumor suppressor role for L3MBTL3 in MB. To further investigate the putative role of L3MBTL3 as a suppressor of MB tumorigenesis, we used our novel L3mbtl3 KO mouse in combination with a genetically engineered ND2:SmoA1 mouse model of SHH MB in a survival analysis. Furthermore, to identify the biological processes regulated by L3mbtl3 in MB, we analyzed by RNA-seq the transcriptome of L3mbtl3 KO mouse cerebella. Our survival analysis validated in vivo our hypothesis that L3mbtl3 is a tumor suppressor in this disease context. Indeed, our data show that [ND2:SmoA1; L3mbtl3+/-] mice have a significantly lower survival rate than ND2:SmoA1 mice (P = 0.032; Log-rank test). Moreover, our RNA-seq studies showed that L3MBTL3 regulates cell fate in the cerebellum via modulation the NOTCH/RBPJ signaling pathway. Hence, the RBPJ-L3MBTL3 interaction is at the heart of a molecular mechanism governing the repression of NOTCH/RBPJ target genes and malfunction of this molecular mechanism contributes to L3MBTL3’s tumor suppressor role in MB through aberrant “de-repression” of NOTCH/RBPJ target genes. Our discovery provides insights into the tumor suppressor role of the L3MBTL3 in MB that could be harnessed in the future for the therapeutic benefit of patients with MB.
CTIM-02. TWO OUNCES OF PREVENTION: A SYSTEMATIC REVIEW AND META-ANALYSIS OF VEGF AND IMMUNE CHECK POINT INHIBITION FOR PRIMARY AND SECONDARY PREVENTION OF BRAIN METASTASES
Authors: Mansouri Alireza , Mansouri Alireza , Brown Timothy , Aregawi Dawit , Zacharia Brad , Glantz Michael 
Published: December 2020

Abstract

INTRODUCTION
As treatments for cancer outside of the central nervous system improve, brain metastases (BMs) are becoming increasingly frequent. Despite novel treatment options, BMs remain a frequent cause of death for many advanced malignancies, and both the metastases and their treatments are associated with profound cognitive, quality of life, and economic costs.

METHODS
We conducted exhaustive, PRISMA-compliant systematic reviews of the literature from January 2000 to June 2020 for studies comparing the frequency of new BM in patients treated with chemotherapy regimens including and not including bevacizumab (“primary prevention”), and for studies comparing the frequency of new outside-of-treatment-field metastases in patients treated with stereotactic radiosurgery (SRS) with or without immune checkpoint inhibitors (“secondary prevention”). Pre-specified data was extracted and summary statistics were calculated using the inverse variance method and random effects model.

RESULTS
Seven studies (n=6,212) reported on BMs in breast, lung, and colon cancer patients treated with chemotherapy with or without bevacizumab. The relative risk (RR) and 95% confidence intervals [95% CI] for the development of new brain metastases was 0.71 [0.55–0.91, p=0.001]. A sensitivity analysis performed on the 3 breast cancer trials (n=2,350) showed a RR of 0.57 [0.34–0.94, p=0.027]. Seven studies (n=609) reported on patients with melanoma BM receiving SRS without or without an ICI. The RR for the development of new out-of-treatment field brain metastases was 0.70 [0.51–0.94, p=0.017]. Results were similar in sensitivity analyses examining only class I and class II trials.

CONCLUSION
This analysis suggests that the addition of bevacizumab to chemotherapy or ICI SRS+/- chemotherapy can reduce the development of first-ever or new BM by 30% in patients with advanced stage breast, lung, or colon cancer. Prospective trials of primary and secondary prevention in patient groups at high risk of developing BMs, and examining additional predictors of response, are currently underway.
CTIM-23. A PHASE 1 TRIAL OF D2C7-IT IN COMBINATION WITH ATEZOLIZUMAB IN RECURRENT WHO GRADE IV MALIGNANT GLIOMA (MG)
Authors: Desjardins Annick , Randazzo Dina , Chandramohan Vidya , Peters Katherine , Johnson Margaret , Landi Daniel , Khasraw Mustafa , Threatt Stevie , Bullock Chevelle , Herndon James , Lipp Eric , Sampson John , Friedman Allan , Friedman Henry , Ashley David , Bigner Darell 
Published: December 2020

Abstract

BACKGROUND
D2C7 immunotoxin (D2C7-IT) is a dual-specific recombinant immunotoxin comprising an EGFR-wt and mutant-specific (EGFRvIII) monoclonal antibody fragment and a genetically engineered form of the pseudomonas exotoxin. When injected directly into the tumor mass by convection enhanced delivery (CED), in addition to direct tumor cell killing, immunotoxins induce secondary immune responses by the activation of CD4+ and CD8+ T-cells. We completed a phase 1 dose escalation study of D2C7-IT injected by CED into recurrent WHO grade III-IV MG and identified the phase 2 dose (6,920 ng/mL). Three patients remain in partial response more than 58, 38, and 32 months after a single D2C7-IT intratumoral infusion. As optimal induction of anti-tumor immune responses by immunotoxins is impeded by potent MG-mediated immunosuppression, we are assessing the toxicity of the combination of D2C7-IT with atezolizumab in patients with recurrent WHO grade IV MG.

METHODS
Eligibility includes adult patients with recurrence of a solitary supratentorial WHO grade IV MG; ≥4 weeks after chemotherapy, bevacizumab or study drug; adequate organ function; and KPS &gt;70%. Patient receives an intratumoral infusion of D2C7-IT and initiates two weeks later atezolizumab at 1200mg, followed by atezolizumab every 3 weeks for up to 2 years. Two cohorts of 3 patients are initially accrued to assess the toxicity of the combination. Assuming accrual continues after the initial two cohorts of 3 patients, an additional 12 patients will be accrued to the study.

RESULT
The first enrolled patient experienced a grade 3 DLT (grade III ALT elevation) after the first infusion of atezolizumab, but showed a more extensive immunotherapeutic effect by imaging than observed with patients on the D2C7-IT monotherapy trial. Enrollment is ongoing.

CONCLUSION
D2C7-IT monotherapy has shown prolonged survival and disease control in some patients. We are now evaluating the combination of D2C7-IT with checkpoint inhibition.
CTIM-25. ONCOLYTIC VIRUS FOR DIPG: THE CLINICAL EXPERIENCE WITH DNX-2401
Authors: M Alonso Marta , Iñigo-Marco Ignacio , Garcia-Moure Marc , González-Huarriz Marisol , Jones Chris , MACKAY Alan , Hulleman Esther , Van der Lugt Jasper , De Andrea Carlos , Villalba Maria , Hernandez Ruben , Hervás Sandra , Tamayo Ibon , Lang Frederick , Gomez-Manzano Candelaria , Fueyo Juan , Diez-Valle Ricardo , de Larraya Jaime Gállego-pérez , Tejada Sonia 
Published: December 2020

Abstract
Despite our increased understanding of Diffuse Intrinsic Pontine Glioma (DIPG) the outcome remains dismal. Recently we showed that the virus Delta-24-RGD (DNX-2401 in the clinic) was effective in preclinical models of DIPG and had the ability to trigger an antitumor immune response. These data allowed us to propel a phase I clinical trial for newly diagnosed DIPGs (NCT03178032) where the patients received an intratumoral viral injection followed by standard radiotherapy. The main objective is to determine the safety, tolerability, and toxicity of DNX-2401. Secondary endpoints are overall survival at 12 months, percentage of responses and induced immune response against tumor. Tumor biopsy was performed through the cerebellar peduncle, followed by intratumoral injection of DNX-2401 (N=12). Three patients were treated with the D1=1x1010vp and because the lack of toxicity we escalated to the D2= 5x1010vp. The procedure was well tolerated and safe. All patients displayed a reduced tumor volume after combined treatment. We performed molecular studies in 9 out of the 12 patients. The immune cell composition of the biopsies was assessed using multiplexed quantitative immunofluorescence. T cells were hardly noticeable in these tumors while macrophages were abundant. We detected increased clonal T cell diversity following treatment with virus in peripheral blood lymphocytes when compared paired pre- and post-treatment samples from the trial. In addition, we measure pre and post treatment neutralizing antibodies and its relationship with survival. Finally, we performed functional studies using 2 cell lines isolated from patients included in this trial to assess the response to the virus (infectivity, viability, T-cell recognition). Overall, the administration of DNX2401 was safe, feasible and therapeutically beneficial in a subgroup of patients. This trial constitutes a proof of principle that aids to understand the response of DIPGs to viral therapies allowing to set the bases to improve this strategy for DIPG.