bluuebunny/crossref_metadata_2025_split huggingface dataset:
P11.60 Neurosurgical delivery of the poly ADP ribose polymerase-1 inhibitor olaparib from a thermo-responsive biodegradable paste potentiates radiotherapy and prolongs survival
Authors: Smith S , Serra R , Rowlinson J , Gorelick N , Veal G , Shakesheff K , Brem H , Grundy R , Tyler B , Rahman R 
Published: September 2019

Abstract

BACKGROUND
There has been considerable interest in repurposing the poly ADP ribose polymerase inhibitor and purported radiosensitiser olaparib (Lynparza), with a recent dose escalation study of olaparib plus temozolomide in recurrent GBM showing good tolerance. Due to systemic therapy-associated caveats such as dose-limiting toxicities and blood-brain-barrier penetration, here we assess localised post-surgical delivery of olaparib from our previously developed PLGA/PEG thermo-sensitive biodegradable paste.

MATERIAL AND METHODS
Metabolic and clonogenic assays were used to assess effects on proliferation and clonal growth upon in vitro glioma exposure to olaparib. Flow cytometry and Annexin V/Propidium iodide were used to determine apoptosis. The 9L high-grade glioma orthotopic allograft model was utilised to assess survival upon intra-cavity olaparib delivery.

RESULTS
Metabolic and clonogenic assays revealed impaired proliferation and clonal growth respectively, upon acute exposure of high-grade glioma cells to olaparib (3–5µM), an effect dramatically potentiated with 3Gy radiation. Flow cytometry of Annexin V+/Propidium iodide+ rodent and human high-grade glioma cells, revealed a significant cell proportion increase at late stage apoptosis when exposed to 2–3µM olaparib and 3Gy radiation (relative to untreated, olaparib alone or radiation alone). A high-grade glioma orthotopic allograft study revealed a significant overall survival benefit of locally-delivered 10% and 20% w/w (drug:polymer ratio) olaparib via PLGA/PEG paste post-surgery with adjuvant radiotherapy, compared to surgery/oral temozolomide/radiotherapy (GBM standard-of-care) and surgery/systemic olaparib (95 vs. 44 vs. 30 days respectively). A more pronounced survival benefit, as measured by number of animals surviving long-term, was observed with combined PLGA/PEG/olaparib/temozolomide/radiotherapy or PLGA/PEG/olaparib/etoposide/radiotherapy, relative to standard-of-care (95 vs. 44 days). Clinical correlation was determined using RNAseq data from 10 GBM patients, showing significantly elevated levels of apoptosis-inducing factor-1 in 5-aminolevulinic acid (5ALA)+ fluorescence-activated cell sorted populations (i.e. purified tumour cells from the invasive margin), relative to 5ALA- cells, confirming PARP-1 activity in infiltrative tumour cells.

CONCLUSION
Collectively our data supports a clinical rationale for localised olaparib delivery with adjuvant radiotherapy.
P11.63 PI3K inhibition in conjunction with the ketogenic diet reduces growth and neuroinflammation in pediatric high-grade glioma
Authors: Noch E , Yim I , Cantley L 
Published: September 2019

Abstract
Background: Pediatric high-grade glioma remains a poorly treatable disease with high mortality.Therapeutic advances have lagged behind that of adult glioblastoma, due to small patient numbers, inappropriate generalization from adult tumor types, and unique biology. The use of targeted therapy has recently gained interest in this disease, but efficacy is limited by therapeutic resistance, often as a result of tumor heterogeneity. In the case of phosphatidylinositol 3-kinase (PI3K) inhibition, clinically relevant PI3K inhibitors represent a strong class of drugs for pediatric high-grade glioma, but their use is associated with insulin feedback that reactivates the PI3K pathway and drives therapeutic resistance. Here, we target insulin feedback that is the primary mechanism of PI3K inhibitor-related therapeutic resistance in pediatric high-grade glioma using the ketogenic diet.
Materials and Methods: Patient-derived pediatric high-grade glioma stem cells were treated with vehicle or the pan-PI3K inhibitor, BKM-120, with glucose deprivation or phenformin to decrease glucose utilization. NSG mice containing patient-derived pediatric high-grade glioma xenografts were treated with vehicle or BKM-120 on a regular or ketogenic diet to determine whether reducing insulin feedback increases BKM-120 efficacy. To determine the effect of glioma cells on neuro-inflammation, we measured pro-inflammatory cytokines in glioma cells treated with BKM-120 and phenformin in comparison to vehicle-treated cells. We then applied conditioned medium from glioma cells treated with BKM-120 and phenformin to cortical neuronal cultures to measure oxidative stress and neuro-inflammation. Results: Pediatric high-grade glioma cells exhibited increased toxicity when exposed to BKM-120 with glucose deprivation or phenformin. Furthermore, mice with intracranial high-grade glioma xenografts survived longer when treated with BKM-120 on the ketogenic diet than with BKM-120 or the ketogenic diet alone. Phenformin reduced the production of pro-inflammatory cytokines by BKM-120-treated glioma cells. Cortical neurons treated with conditioned medium from BKM-120- and phenformin-treated glioma cells exhibited less oxidative stress than those treated with BKM-120 alone. Our results demonstrate that strategies to lower glucose utilization and insulin feedback increase efficacy of BKM-120 and decrease neuro-inflammation.
Conclusions: We show that strategies to lower glucose utilization and insulin feedback increase efficacy of BKM-120. Furthermore, reducing insulin feedback decreases the production of pro-inflammatory cytokines in tumor cells and reduces oxidative stress in neurons treated with conditioned medium from BKM-120-treated glioma cells. By using the ketogenic diet to reduce glucose levels, this strategy may enhance efficacy of PI3K inhibitors in this patient population.
P12.01 Local implantation of thermoresponsive interferon alpha-polypeptide conjugate combined with temozolomide for post-surgical glioblastoma chemoimmunotherapy
Authors: Liang P , Zhuoran W , Weiping G , Guihuai W 
Published: September 2019

Abstract

BACKGROUND
Glioblastoma(GBM) is associated with gloomy prognosis despite maximal safe resection and following chemoradiation. In recent years, significant progress has been made in cancer immunotherapy except for GBM, which is largerly due to its local immunosuppressive microenvironment. Some research has demonstrated that local immunotherapy may be more efficient than systematic administrators. IFNα has been investigated as antitumor agent for some cancers, including glioma. Nevertheless, the short circulating half-life greatly limits its clinical application. Hence, a thermoresponsive IFNα-elastin-like polypeptide (IFNα-ELP) was genetically engineered for the earliest local intervention post-surgery.

MATERIAL AND METHODS
Firstly, IFNα-ELP(V) was constructed, expressed and purified, then, its physicochemical characterization was verified. The tumor was resected 10 days after U87MG-mCherry-luc cells orthotopic implantation, and IFNα-ELP(V) was injected into the resection cavity. Two days later, temozolomide(TMZ) was intraperitoneally injected. Using in vivo imaging technique, we could monitor the trends in tumor size. The survival time of mice was counted. Biosafety was evaluated by peripheral blood biochemistry analysis and pathology of the organs.

RESULTS
In this study, the bioconjugate not only in situ deposited in the resection cavity because of the thermoresponsive characteristic, but also showed zero-order release kinetics from the depot and dramatically improved pharmacokinetics and biodistribution of IFNα. Consequently, it showed the inhibition of tumor relapse in GBM orthotopic resection mice models. When followed by TMZ intraperitoneal injection, IFNα-ELP(V) could significantly prevent the tumor recurrence than itself or TMZ alone. Biosafety results indicated that the systemic toxicity of IFNα-ELP(V) in mice can be reduced to safe levels.

CONCLUSION
The results reveal that local implantation of thermoresponsive IFNα-ELP(V) combined with TMZ exhibits the synergy of post-surgical GBM chemoimmunotherapy.
P12.07 Minimal bimodular G-quadruplex nano-construct as cryptic therapeutic DNA oligonucleotide to suppress glioblastoma cell functioning
Authors: Kopylov A , Antipova O , Legatova V , Samoylenkova N , Savchenko E , Golovin A , Zavyalova E , Pavlova G 
Published: September 2019

Abstract

BACKGROUND
G-quadruplex folding oligodeoxyribonucleotides (G4 ODNs) are considers to be potential anticancer agents, because G4 interferes with some functions of cell, like survival, proliferation, ets, by interacting with G4 binding regulatory proteins. There are some experimental data on anti-proliferative activities of G4: for telomerase complex, aptamers for STAT3, nucleolin, TOP1, SP1, VEGF, and SHP-2, but there is no molecular mechanism yet. Because ODNs are supposed to block regulatory proteins, like cryptic aptamers do, they could be potentially therapeutics, like monoclonal antibodies. The only current approach to find proper model for G4 plus reference cell line, is to screen sets of G4 for sets of cancer cell lines. To avoid selection from large number of G4 structures, we have initiated anti-proliferative study of minimal DNA nano-construct biHD1, built from two minimal active G4 15-mer, by testing 7 human cancer cell lines, including glioblastoma (GBM): U87 and primary cultures from GBM surgery samples.

MATERIAL AND METHODS
ODN were from Evrogen (Russia). ODN were folded: heated to 950C, slowly cooled to 250C. biHD1, GGTTGGTGTGGTTGG TGGTTGGTGTGGTTGG, and derivatives with G4 structure variations. CD in saline phosphate, pH 7.5; CHIRASCAN (UK) and MARK-5 (France); melting curves at 294 nm. 7 human cancer cell lines: colon, HCT116; prostate, PC3; lung, RL-67; breast adenocarcinoma, MCF7; melanoma, mS; HeLa; GBM, U87 and primary cultures from surgery samples; and human embryonic fibroblast, hEF, as control. MTT for cell viability by colorimetric measurements of metabolic activity (Tecan plate reader, Switzerland). ODN: 0.10 μM, 1.0 μM, 10 μM for 3 days.

RESULTS
biHD1 is dose-dependent toxic for several human cancer cell lines, most active for lung cancer RL-67 and GBM U87, survival at 10 μM ODN 35% and 45%, respectively. According to data for biHD1 derivatives with deviations from G4 conformation: length of linker joining modules, light distortions of loops, strong distortions of G4, freezing of G4 conformation, it is G4 fold which is responsible for toxicity for U87 cell line.

CONCLUSION
Cell survival after treatment with G4 minimal bimodular DNA oligonucleotide biHD1 and its derivatives have been tested for 7 human cancer cell lines, including CNS, U87. biHD1 is toxic for cancer cells, but not for embryonic fibroblast, as control; activity depends on G4 fold. Therefore, it is possible to manipulate with minimal G4 as module, and build G4 nano-construct being toxic for cancer cells, including GBM, U87.
Research is supported by RFBR grants 17-00-00157, 18-29-01047
P12.09 Multidimensional Personalized Response Assessment to Microglia Modulators in Gioblastoma Bioreactors
Authors: Shekarian T , Wachnowicz A , Flammer J , Paganetti C , Martins T , Muraro M , Schürch C , Hutter G 
Published: September 2019

Abstract

BACKGROUND
Recently, strategies harnessing the non-neoplastic, immune tumor microenvironment (iTME) consisting of myeloid-derived macrophages and yolk sac derived microglia (termed TAMs) as well as adaptive immune components have been employed to treat glioblastoma (GBM). To evaluate the effect of TAM-modulating therapies in combination with T-cell checkpoint inhibitor approaches, we generated 3D GBM bioreactor cultures from patient-derived samples. Here, we report patient-tailored, tumor region specific response assessment to microglia modulators and T-cell checkpoint inhibitors using multidimensional fluorescent microscopy techniques

MATERIAL AND METHODS
GBM tissue fragments from the tumor center and periphery were placed into perfusion bioreactors shortly after resection and cultured for up to 3 weeks. Control conditions included non-perfused cultures of the same tissue. Cultures were treated with combinations of TAM and T-cell modulating, FDA approved drugs including anti-PD1, anti-CTLA4 and anti-CD47 antibodies. Tissue was harvested for histology, RNA extraction, and supernatants were processed for multiplexed cytokine analysis. Multidimensional CODEX technology analysis using a customized TAM/microglia-centric 50 marker panel was implemented, and a map of individualized response criteria to specific immunotherapies developed.

RESULTS
We were able to cultivate viable GBM tissue with intact iTME. Tumor cell proliferation and invasion capacity were preserved for up to 3 weeks. Conventional immunohistochemistry confirmed the presence of TAMs and T cells. Treatment with immunomodulators resulted in a profound polarization shift of TAMs. Furthermore, cytokine analysis confirmed proinflammatory immune responses in most assessed samples. We present preliminary data of the CODEX analysis of our combinatorial immunotherapies in a series of 8 patient-specific explant samples.

CONCLUSION
GBM tissue could be incubated in the perfused 3D bioreactor model and kept viable for up to 21 days. The proposed model allows patient-tailored testing of immunomodulatory drugs by taking into account the patients individual iTME response. GBM tissue could be incubated in the perfused 3D bioreactor model and kept viable for up to 21 days. The proposed model allows patient-tailored testing of immunomodulatory drugs by taking into account the patients individual iTME response.
P13.01 TERTpromoter methylation is significantly associated withTERTupregulation and tumor progression in pituitary adenomas
Authors: Adachi J , Miyake Y , Suzuki T , Mishima K , Araki R , Nishikawa R 
Published: September 2019

Abstract

BACKGROUND
Activation of telomerase plays a critical role in tumor development. Somatic alterations in the promoter of the telomerase reverse transcriptase (TERT) gene are a major mechanism of upregulating telomerase. Several mechanisms have been associated with TERT abnormalities, including TERT promoter mutations or methylation. Mutations in the TERT promoter have been observed in a subset of brain tumors, especially in adult gliomas. In pituitary adenomas (PAs), however, TERT abnormalities are not fully understood. The present study aimed to investigate not only mutational but also methylation status changes in the TERT promoter in PAs and to analyze their correlations with clinical variables.

MATERIAL AND METHODS
We retrospectively studied 70 PAs consisting of 53 primary and 17 recurrent samples. Clinical data, including age at surgery, sex, tumor size, tumor subtype, resection rate, presence or absence of postoperative irradiation, and progression-free survival (PFS), were obtained from medical records. First, we investigated TERT promoter hotspot mutations via Sanger sequencing. Next, we quantified the methylation status of the TERT promoter using methylation-sensitive high-resolution melting analysis (MS-HRM). Finally, we investigated TERT mRNA expression levels using real-time quantitative PCR. Fisher’s exact test was applied to evaluate the statistical significance between TERT promoter methylation status and tumor recurrence. PFS was calculated using Kaplan-Meier estimates and compared between methylated with ummethylated PAs with the log-rank test. The correlation between TERT promoter methylation status and mRNA levels was analyzed with the Mann-Whitney U-test. PFS was analyzed using multivariate analysis with the Cox proportional hazards model and included the following variables: age, sex, tumor size, tumor subtype, resection rate, radiation therapy, and methylation status.

RESULTS
TERT promoter hotspot mutations were not observed in any PA sample. Nineteen percent of PAs exhibitedTERT promoter methylation, which was significantly predominant in recurrent PA samples. PFS was significantly shorter in the methylated cases than in the unmethylated cases. Higher TERT expression levels were correlated with methylation status.

CONCLUSION
We found that TERT promoter methylation upregulated TERT expression and was associated with shorter PFS in PAs. Our results suggest thatTERT promoter methylation may be a potential biomarker for predicting tumor recurrence in PAs.
P13.03 Identification of novel gene fusions in glioblastomas with chromothripsis
Authors: Ah-Pine F , Casas D , Boisselier B , Guardiola P , Menei P , Garcion E , Rousseau A 
Published: September 2019

Abstract

BACKGROUND
Genomic rearrangements are thought to occur in a stepwise manner during cancer development. Recent findings, however, suggest an alternative mechanism, involving massive chromosome (chr) rearrangements in a one-step catastrophic event termed chromothripsis (CT). In this scenario, the chr shatters into tens to hundreds of pieces, some of which are then stitched together in a mosaic patchwork of genomic fragments. Such random stitching may give rise to fusion genes with oncogenic potential. CT has not been thoroughly studied in diffuse gliomas, such as glioblastomas (GB). The aim of the project was to detect CT in GB and identify novel fusion genes in CT regions. Those genes are potential therapeutic targets.

MATERIAL AND METHODS
170 de novo IDH wild-type GB were screened for CT patterns using whole genome SNP arrays. RNA sequencing was performed in 52 cases with CT features to identify novel fusion genes within the rearranged genomic regions. Expression levels of transcripts were measured using FPKM (fragments per kilobase of exon per million fragments mapped) normalization method. Candidate fusion genes were validated by RT-PCR followed by Sanger sequencing.

RESULTS
Out of 66 GB with CT patterns (66/170, 38.8%), 40 cases (out of 52 RNA-sequenced cases, 77%) harbored at least one fusion gene within CT regions, which were mostly detected on chr 7, 9, and 12. Overall, 137 candidate fusion genes were identified, 26 of which with a predicted open reading frame. Twelve out of 26 fusions were validated by RT-PCR followed by Sanger sequencing (validation of the remaining fusions is ongoing). The fusions involved either well-known key oncogenes such as EGFR, MDM2, and MET or potential oncogenes (CPM, PPM1H, SEPT14, SEC61G) with a yet-to-discover role in GB pathogenesis. GB with CT on chr 12 (11/66, 16.7%) showed a distinct transcript expression profile at the locus 12q13-15, particularly in the vicinity of MDM2 and CDK4 genes. In our cohort, this so-called “multi-aberration region” recurrently harbored gene fusions, involving, among others, CPM (12q15). CPM, encoding an extracellular membrane-bound carboxypeptidase, is recurrently amplified in liposarcoma and is a potential oncogene involved in the EGFR signaling pathway. Three cases (3/26, 11.5%) harboring an in-frame gene fusion involving CPM showed higher levels of CPM transcripts and did not exhibit any EGFR amplification. Gene fusions involving CPM might constitute an alternative mechanism of EGFR pathway activation in de novo IDH wild-type GB.

CONCLUSION
The occurrence of CT points to underlying gene fusions in IDH wild-type GB. Such fusions may drive tumorigenesis and represent promising therapeutic targets. We identified CPM as a recurrent fusion partner and a potential alternative mechanism of EGFR signaling pathway activation in de novo IDH wild-type GB.
P13.06 Transcriptome-wide Mendelian randomization study to identify brain-specific causal genes influencing glioma
Authors: Robinson J W , Zheng J , Tscavachidis S , Howell A E , Relton C L , Armstrong G N , Bondy M , Martin R M , Kurian K M 
Published: September 2019

Abstract

BACKGROUND
The drug treatment regimen for glioma has remained relatively static since the introduction of temozolomide, although new drugs and drug combinations are being trialled. The human transcriptome can provide promising insights into causal genes as potential drug interventions for glioma treatment and may guide drug discovery methods.

MATERIAL AND METHODS
We apply two sample Mendelian randomisation and colocalisation to explore the influence of genetically-predicted gene expression across 12 tissue types located in the brain (4,554 genes from GTEx) and whole blood (16,112 genes from eQTLGen) on glioma risk (5,739 cases, 5,501 controls from a meta-analysis of GICC and MDA glioma GWAS). We used the MR-Base R package to conduct these analyses.

RESULTS
We identify 9 genes whose genetically-predicted expression was strongly associated with glioma risk. Of these genes, 7/9 are shown to have tissue-specific expression while the other two genes showed an association with glioma across multiple brain tissues and whole blood. For example, JAK1, involved in the well-known JAK-STAT pathway, is found in the frontal cortex (OR=1.49 for glioma per standard deviation increase in gene expression; 95% CI: 1.28 to 1.73; P=1.79 × 10−7), the cerebellar hemisphere (OR=1.32; 95% CI: 1.19 to 1.47; P=2.64 × 10−7), the cerebellum (OR=1.27; 95% CI: 1.16 to 1.39; P=2.64 × 10−7) and the cortex (OR=1.38; 95% CI: 1.22 to 1.57; P=2.64 × 10−7). This pathway has been highlighted in previous research as a potential intervention target for glioma therapies. We found that 5/9 of the genes from the MR analysis are expressed in the cerebellum. However malignant cerebellar glioma is a rare tumour (~3% of all malignant gliomas). This suggests that tumourigenesis elsewhere in the brain may be affected by other tissue-specific genes, specifically in the cerebellum, though this will require further research to elucidate. We further triangulate the MR findings with evidence from the OpenTargets platform to strengthen the putative causal associations. OpenTargets aims to “generate evidence on the validity of therapeutic targets based on genome-scale experiments and analysis”. For example, JAK1 receives an overall OpenTargets score of 0.89 out of 1, with most of the evidence for this JAK1-glioma association coming from affected pathways data.

CONCLUSION
This study has combined genetic epidemiological approaches to the analysis of the human transcriptome on glioma incidence. We provide evidence that these genes may inform putative drug targets for tertiary treatment of glioma. Future research specifically towards this aim will be required to fully elucidate intervention targets.