bluuebunny/crossref_metadata_2025_split huggingface dataset:
P10.05.B Platelet-derived growth factor signalling pathways in patient-derived glioblastoma cells
Authors: Li S Y , Schweder P , Correia J , Park T I , Dragunow M 
Published: September 2022

Abstract

Background
Platelet-derived growth factor (PDGF) signalling is essential in the development and maintenance of the neurovasculature. Of particular importance is PDGFRβ signalling for the recruitment and maintenance of the mural cell type pericytes, which occupy an important position in coordinating blood-brain barrier functions. The PDGF pathway is also implicated in glioblastoma, where overexpression of PDGFRα is a signature of the proneural subtype of the highly malignant and invasive tumour. The expression and signalling of both PDGFRα and β by tumour cells have been implicated in tumorigenesis and progression. Therefore, we sought to study PDGF receptor signalling in primary human-derived glioblastoma tumour cells to gain a better understanding of the signalling mechanisms driven by these receptors.

Material and Methods
Primary human epilepsy pericytes and glioblastoma tumour cells were isolated from surgical resections obtained from consenting patients at Auckland City Hospital. PDGF signalling pathways were investigated through treatment with exogenous PDGF ligands. Pathway activation was quantified using immunocytochemistry, human cytokine XL Proteome Profiler and cytometric bead arrays.

Results
PDGF-BB and PDGF-DD treatment led to the activation of PDGFRβ in pericyte cultures, which mediated the activation of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt cascades, ultimately increasing pericyte proliferation and cytokine secretion. PDGF-AA treatment resulted in transient MAPK activation, but was not followed by increased proliferation in pericytes. In contrast, although PDGF-AA, -BB and -DD induced PDGFRα internalisation (and PDGF-BB and -DD induced PDGFRβ internalisation) in GBM tumour cells, this did not result in MAPK or PI3K/Akt activation or cell proliferation.

Conclusion
Despite PDGF receptor expression, the GBM tumour cells, in contrast to pericytes, surprisingly displayed a lack of responses to ligand stimulation through either PDGFRα or PDGFRβ. This warrants further investigation into the signalling mechanisms behind tumour cells to better understand tumour biology.
P10.10.A Tumor Treating Fields (TTFields), temozolomide and lomustine co-application is efficacious in glioblastoma cancer cell lines
Authors: Fishman H , Monin R , Dor-On E , Wolfbauer C , Haber A , Giladi M , Weinberg U , Palti Y 
Published: September 2022

Abstract

Background
Temozolomide (TMZ) is the standard of care chemotherapy for newly diagnosed glioblastoma (ndGBM), the most common primary malignant brain tumor in adults. However, 50% of patients do not respond to TMZ due to expression of O6-methylguanine-DNA methyltransferase (MGMT), the enzyme involved in repair of TMZ-induced damage. Tumor Treating Fields (TTFields) are alternating electric fields that display anti-mitotic effects on cancerous cells, and have been shown to induce a state of BRCAness in various cancer types. Concurrent treatment with TMZ and TTFields demonstrated a major advance in treatment of patients with ndGBM, and was approved by the FDA in 2014. Recently, the addition of lomustine (CCNU) to TMZ demonstrated clinical benefit in ndGBM patients, with improved overall and progression free survival. The aim of the current study was to examine in GBM cells the effect of TTFields in conjunction with TMZ and CCNU.

Materials and Methods
U-87 MG, LN229, U118 and LN18 human GBM cell lines were tested for their MGMT expression levels, and treated with TTFields (200 kHz, of 0.83 V/cm RMS) for 72 h using the inovitro system. Efficacy of concomitant application of TTFields with TMZ and/or CCNU was tested by measuring cell count, colony formation, and apoptosis levels.

Results
U-87 MG and LN229 displayed no expression of MGMT, while U118 and LN18 expressed low and high levels of MGMT, respectively. Application of TMZ and TTFields resulted in increased cytotoxicity compared with each treatment alone, with an additive interaction seen in all examined cell lines. The cytotoxic effect resulting from co-application of CCNU with TTFields suggested a synergistic interaction between the two modalities for U-87 MG, LN229, and U118, an additivity for LN18. Concurrent TTFields/TMZ/CCNU was more efficacious than TTFields or TMZ/CCNU separately in all cell lines.

Conclusions
Application of TTFields with TMZ was additive, irrespective of MGMT expression levels, while TTFields with CCNU was additive when MGMT was plentiful, but displayed tendency to synergism when MGMT was absent or limited. These outcomes are in line with the BRCAness state induced by TTFields, as in the absence of MGMT, DNA damage induced by CCNU requires the BRCA pathway for repair. Application of TTFields together with TMZ and CCNU demonstrated increased efficacy, suggesting potential benefit of such therapy for ndGBM treatment.
P10.17.B Androgen receptor signalling has independent prognostic value and is associated with resistance to temozolomide and tumour growth in glioblastoma
Authors: Birzu C , Boussier J , Belin L , Da Costa Pereira T , Quissac E , Zerara M , Lemaire N , Mokhtari K , Verreault M , Idbaih A 
Published: September 2022

Abstract

Background
The spectrum of sex differences in glioblastoma (GBM) is a rising topic. GBM is more frequent (sex ratio M:F=1.6) and seem to have worse prognosis in males (M) compared to females. Androgen receptor (AR) is expressed in GBM but its role in GBM biology and clinics is not yet fully understood.

Material and Methods
We have selected from our tumour tissue bank: (i) GBM samples with clinical, pathological and molecular annotations and (ii) GBM-patient derived cell lines -GBM-PDCL- with transcriptomic profiling and available tissue from parental tumours.AR expression was investigated using multiplex IHC Opal stained-FFPE sections. Sensitivity of PDCL to hormonotherapy (dihydrotestosterone or enzalutamide EZT) alone or combined with temozolomide (TMZ) was tested using WST1 viability assay. Response to drugs were correlated to AR expression (high: log2 [FPKM] &gt;2 or low: log2 [FPKM] &lt;2). PDCLs dihydrotestosterone secretion was examined by ELISA in both supernatants and cell lysates.

Results
In our cohort of 1188 IDH muted GBM patients, the median follow-up was 27.7 (25.8-31.3). The sex ratio M:F was 1.68 and the median age at diagnosis was 57 years [18-69]. Compared to males, females have better prognosis with a median overall survival of 26.1 months vs 20.8 months (p&lt;0.0001). In multivariate analysis, male gender was an independent prognostic factor with a HR of 1.43 CI95%(1.21-1.69) (p&lt;0.0001) adjusted on age, MGMT status and Karnofsky indice . Although interaction between age and sex was not significant (p = 0.854), HR of gender varied through age category 1.53 CI95%( 1.01-2.33 ), 1.51 CI95%( 0.888-2.55 ) and 1.38 CI95%( 0.857-2.21) for males &lt;45 years, between 46-55 years and &gt; 55 years respectively. In GBM tumours, AR staining was positive in 5- 30% tumour cells. After 72h exposure to 10nM dihydrotestosterone, ARhigh GBM-PDCLs exhibit AR nuclear translocation and c-myc expression upregulation, suggesting functional activation of the receptor. AR pharmacological blockade increased temozolomide sensitivity in ARhigh GBM-PDCLs regardless of the patient’s sex. Moreover, ARhigh PDCLs secreted DHT, suggesting autocrine and paracrine AR stimulation in tumour microenvironment.

Conclusion
Our study highlights the independent prognostic significance of sex in GBM patients, where males exhibit a worse prognosis. In GBM-PDCL, we show that androgen receptor is (i) functional in vitro and (ii) associated with resistance to temozolomide. Further studies are needed to investigate the role of AR in tumour tissue microenvironment.
P10.21.B Pharmacogenomics profiling of gliomas for precision medicine
Authors: Lipsa A , Hau A , Ermini L , Toth R , Oudin A , Klink B , Hertel F , Mittelbronn M , Golebiewska A , Niclou S 
Published: September 2022

Abstract

Background
Molecular characterization based on genomic, transcriptomic and epigenetic profiling has led to a better delineation of various glioma subtypes and highlighted the individual paths of glioma evolution upon treatment and recurrence. However, due to cellular and molecular diversity of these tumors, the pharmacological treatment of gliomas, in particular of its most malignant subtype Glioblastoma (GBM), remains a major challenge. To address this challenge, we here apply a pharmacogenomics approach, modelling the disease in matched patient-derived preclinical models and profiling the differential drug response among individual patients and glioma subtypes

Material and Methods
We generated a cohort of 45 Patient-Derived Orthotopic Xenografts (PDOX) from a collection of over 400 glioma patients. We used a multi-parametric approach based on genetic, transcriptomic and longitudinal profiling of patients and their matched xenografts for a comprehensive subgrouping of our glioma cohort. Based on PDOX-derived 3D tumor organoids we carried out a targeted drug screen focused on epigenetic regulators. A high throughput drug screening using an unbiased large chemical library containing a unique collection of FDA approved compounds with high pharmacological diversity is currently ongoing.

Results
Our glioma cohort with matched PDOX and 3D tumor organoids represents diverse subgroups of glioma patients, including a unique collection of primary and relapsed tumors from the same patient. Our preliminary drug screen analysis on 3D organoids highlights selective susceptibility to certain epigenetic inhibitors in primary disease but not in the same patient’s relapse. Results of matching genomics and functional data will be presented.

Conclusion
An integrated personalized approach to profile gliomas at multiple genomic and functional levels allows for pharmacogenomic subgrouping of patients for personalized treatment strategies. This analysis will allow to link genotypes to functional phenotypes and hopefully identify therapeutic options for selected glioma sub-populations.
P10.22.A Prognostic role ofTCF7L2 in glioblastoma
Authors: Radu R , Petrescu G E D , Ionita R , Gafencu A , Brehar F , Gorgan R M 
Published: September 2022

Abstract

Background
Glioblastoma is the most common and devastating brain cancer and despite maximal surgical resection, chemotherapy and radiotherapy, the five-year survival rate is less than 7%. The TCF7L2 gene encodes transcription factor 7-like 2, a main effector of Wnt/β-Catenin signaling pathway involved in cancer development and progression. Aberrant activation of the TCF7L2 gene is one of the primary events in tumorigenesis by maintaining stem-cell characteristics, however its role in glioblastoma is poorly studied.

Material and Methods
The expression of TCF7L2 was analyzed by qRT-PCR in a series of consecutive glioblastoma samples from patients that underwent surgical resection. Secondary or recurrent glioblastomas were excluded from the analysis. All patients underwent radio- and chemotherapy according to the protocol. Housekeeping gene RPL13 was used as reference gene. The 2-ΔCT method was used to calculate the relative expression of TCF7L2 to the reference gene.

Results
A total of 49 glioblastoma samples were included in the study. The mean survival period was 58.2 weeks. The median value of TCF7L2 expression was used as a cut-off point for the survival analysis. There were no statistically significant differences regarding the clinical and histopathological factors between the groups with low and high expression of TCF7L2. By using the Kaplan-Meier analysis, we observed that patients with overexpression of TCF7L2 had a decreased survival rate compared to patients with low levels of TCF7L2 (38.8 weeks vs. 77.34 weeks, p = 0.001).

Conclusion
These results demonstrate that glioblastoma patients with high levels of TCF7L2 have a poorer survival rate and TCF7L2 might be a useful prognostic factor for these patients. However, further studies are needed to elucidate the mechanisms through which TCF7L2 affects the prognosis and its implication as a possible therapeutic target.
This work was supported by an ERA PerMed grant - ERAPERMED2018-270 (PerProGlio).
P10.23.B Polycystin-1 induces mechanotransduction pathways in gioblastoma cells under hydrostatic pressure
Authors: Zoi I , Gargalionis A , Papavassiliou K , Nasiri-Ansari N , Piperi C , Basdra E , Papavassiliou A 
Published: September 2022

Abstract

Background
Increased mechanical load and stiffness of the tumor microenvironment are key features during progression of gliomas. Polycystin-1 (PC1) is a mechanosensitive protein which perceives extracellular mechanical cues. The aim of the study was to investigate PC1 participation in mechanisms of glioblastoma (GBM) progression under a mechanically-induced microenvironment.

Material and Methods
We generated monolayer cell cultures and tumor spheroids of the T98G glioblastoma cell line. Cells were subjected to continuous hydrostatic pressure (HP), inhibition of PC1 mechanical perception through functional blockage of its extracellular domain, and silencing of PKD1 expression. The level of activation of PC1 mechano-induced downstream kinases (mTOR, ERK, FAK) and transcription factors (YAP, TAZ) was evaluated via Western blot at specific time-points. Functional assays were performed to assess cell proliferation, clone formation, and cell migration. qPCR was employed to quantify the mRNA expression of markers regarding certain traits of cancer cells.

Results
In monolayer cell cultures, PC1 functional inhibition under HP is associated with mTOR and ERK activation and elevated expression of TAZ. On the other hand, PKD1 knockdown under HP is associated with activation of FAK, but not mTOR or ERK. In tumor spheroids, PC1 inhibition acts in synergy with HP to activate FAK and upregulate YAP, but not ERK or mTOR. PC1 inhibition under HP is associated with compact 3-dimensional spheroid structures. PC1 inhibition acts in synergy with HP to suppress cell proliferation, clone formation, and cell migration in GBM cells. The same synergistic effect is observed on the expression of respective markers of apoptosis, angiogenesis, proliferation, and epithelial-to-mesenchymal transition of GBM cells.

Conclusion
PC1 seems to be able to sense applied mechanical forces in GBM cells by regulating the activity of downstream molecules and enhance certain traits of tumor promotion. This work was co-financed by Operational Programme “Human Resources Development, Education and Lifelong Learning”, National Strategic Reference Framework (NSRF) 2014-2020, Ministry of Economy and Development, Greece & European Union (European Social Fund (ESF), in the context of the project “Investigation of the role of polycystin proteins in glioma neoplastic cells”; Grant/Award Number: MIS 5047967
P10.24.A A personalized BRAF mutant glioblastoma with Human2Humanex-vivo cortical cultures
Authors: Zhang J , Joseph K , Beck J , Schnell O , Ravi V M , Heiland D H 
Published: September 2022

Abstract

Background
Glioblastoma is among the most common primary malignancy with a poor medium survival post-diagnosis. The incredible heterogeneity of glioblastoma highlights its incurable nature. Methods to overcome difficulties leaded by glioblastoma heterogeneity remain to be explored. Here we present our Human2Human personalized autografted BRAF(V600E) mutant glioblastoma model, focusing on the idea of precision. This model, with an inoculation of self-derived glioblastoma cells, can imitate the tumor growth, invasion, metabolism and microenvironmental crosstalk within its “native” microenvironment and allows us to investigate the influence of different chemotherapies on the immunosuppressive tumor microenvironment from each specific individual glioblastoma patient.

Material and Methods
Non-neoplastic cortical tissue was obtained from a BRAF(V600E) mutant glioblastoma patient during surgical operation. Tissue was sectioned and inoculated with autografted glioblastoma cells in order to establish the ex-vivo Human2Human personalized brain slice model. Slice viability and tumor growth were monitored throughout the culture period, with and without day-wise refreshed treatments of clinically proved BRAF/MEK inhibitors. Sections were fixed and stained post cultivation. Pathway proteins p-ERK, p-Akt based on BRAF signaling along with markers (TMEM119, Iba-1, CD3, CD68, GFAP and NeuN) for major cell types in the environment were stained. Single Nuclei RNA Sequencing and Spatially Resolved Transcriptomics were applied.

Results
Tumor growth quantification over the culture period revealed different tumor reaction and tolerance towards various chemotherapies. The combination of Vemurafenib + Trametinib exhibited more efficient therapy response in comparison with either Dabrafenib + Trametinib or Encorafenib + Trametinib. Immunofluorescence and immunohistochemistry based quantification referring to neurons (NeuN), astrocytes (GFAP) and microglia/macrophage cells (Iba-1) suggested no toxic effects of the drug combinations on the tumor microenvironment. BRAF pathway proteins and immune cells showed various activation patterns upon different treatment combinations on an immunofluorescence base. Single Nuclei RNA Sequencing revealed the mesenchymal differentiation of BRAF mutant glioblastoma cells. Spatially Resolved Transcriptomics characterized tumor recurrence and suggested the therapy response accurately and visually.

Conclusion
The combination of Vemurafenib + Trametinib shows strategy to this specific BRAF mutant glioblastoma patient. And therefore, this Human2Human personalized model has a potential to provide in-depth information of the spatio-temporal tumor differentiation ex-vivo, correct inter-patient bias, and model therapy response in a very short time frame to provide drug testing results for clinical decision making.
P11.10.A An assessment of predictive factors for overall survival in glioblastoma - MGMT methylation is solely important for younger patients
Authors: Krigers A , Cosar T , Kerschbaumer J , Demetz M , Pinggera D , Thomé C , Freyschlag C F 
Published: September 2022

Abstract

Background
Diverse groups of factors - neuropathological characters, tumor position and epidemiological data - have been proposed for outcome evaluation of glioblastoma (GBM). We compared clinical signs, neuropathological features and the locus of the tumor with the follow-up data.

Material and Methods
All adult patients with firstly diagnosed and histologically proven GBM (according to WHO 2016), which were operated in our center between January 2010 and June 2021 were retrospectively assessed. Epidemiological, clinical and neuro-pathological characteristics were acquired from our institutional neuro-oncological database.

Results
A total of 399 patients could be evaluated. The mean follow-up was 13.9 months (CI95 12.2-15.6), within 266 (67%) patients were deceased. Estimated mean OS for entire cohort was 24.2 months (CI95 19.8-28.7). Age, MGMT promoter methylation, brainstem localization or if a patient received biopsy only showed significant impact on OS. Each year of life accounted for 3.4% additional hazard to decease (HR=1.034, CI95 1.020-1.048, p&lt;0.001). If patients were younger than 65 years, mean OS was 34 months (CI95 26.5-41.8) compared to older than 65 years patients with a mean OS of 14.3 months (CI95 10.5-18.1, p&lt;0.001). Generally, an unmethylated MGMT promoter status was linked to 75% higher hazards to decease (HR 1.75, CI95 1.27-2.40, p=0.027). If MGMT promoter status was methylated, mean OS was 25.7 months (CI95 19.9-31.5) or more compared to unmethylated with 14.5 months (CI95 12.0-16.9, p=0.01). Presence of MGMT promoter methylation showed influence on OS only in the younger cohort (&lt;65y, mean OS 38.7 months [CI95 28.9-48.6]; HR 2.60 [CI95 1.55-4.37], p&lt;0.001) as opposed to unmethylated MGMT (mean OS 17.7 months [CI95 14.1-21.2], p&lt;0.001). In the older cohort (&gt;65y) presence of methylated MGMT promoter showed no significant difference (p=0.364). For patients who received only biopsy, 2.4 times more hazards for worse OS were revealed (HR 3.36, CI95% 2.30-4.90, p&lt;0.001). In these cases, mean OS was 7.1 months (CI95 5.3-8.8). Other factors, including gender or preoperative seizures, as well as EGFR, p53, IDH1, ATRX and TERT status did not show impact on OS in our series.

Conclusion
In our cohort, MGMT promoter methylation showed an impact on OS only in younger patients &lt;65 years of age. Biopsy of GBM should only be considered very selected patients when resection is not possible.
P11.15.B First multicentric real-life experience with the combination of lomustine and temozolomide in newly diagnosedMGMT promoter methylatedIDH wildtype glioblastoma
Authors: Lazaridis L , Schmidt T , Agkatsev S , Blau T , Spille D , Heider S , Schulz T , Bumes E , Oster C , Feldheim J , Stummer W , Kessler A , Seidel C , Hau P , Sure U , Keyvani K , Herrlinger U , Kleinschnitz C , Stuschke M , Herrmann K , Deuschl C , Hattingen E , Scheffler B , Kebir S , Glas M 
Published: September 2022

Abstract

Background
The CeTeG/NOA-09 trial assessed in a randomized phase 3 setting, whether combined treatment of lomustine together with temozolomide was superior to temozolomide treatment alone in newly diagnosed MGMT (O(6)-methylguanine-DNA-methyltransferase) promoter methylated glioblastoma patients. Survival was significantly improved from 31.4 months with temozolomide alone to 48.1 months with the combination of lomustine plus temozolomide. In view of this encouraging data - suggesting this combination could have a significant impact on the survival of newly diagnosed glioblastoma patients - we were curious to assess safety and efficacy of this regimen under real-life conditions.

Material and Methods
We collected clinical and radiographic data from adult newly diagnosed MGMT promoter methylated IDH (isocitrate dehydrogenase) wildtype glioblastoma patients treated at five neuro-oncology centers in Germany. As a requirement for inclusion, first-line treatment with lomustine plus temozolomide had to be performed for at least six weeks (one course). The available radiographic data was independently reviewed by an experienced board-certified neuro-radiologist.

Results
In total, 70 patients were included. Median progression-free survival of the full cohort was 14.4 months and median overall survival was 36.0 months. Patients who received TTFields (Tumor Treating Fields) treatment for eight weeks or longer together with the combination of lomustine plus temozolomide (n=22, 31%) had a prolonged progression-free survival compared to those patients who received TTFields treatment less than eight weeks or did not receive treatment with TTFields (n=48, 69%) (21.5 months versus 11.2 months; HR: 2.118, 95% CI: 1.245-3.605; p=0.0105). In a multivariable Cox regression analysis the use of TTFields for eight weeks or longer together with the combination of lomustine plus temozolomide as well as the application of at least five courses of CeTeG therapy emerged as independent prognostic factors for progression-free survival and overall survival. Pseudoprogression occurred in n=16 (33%) of the patients. We observed no treatment related deaths and high-grade hematotoxicity in n=31 (44%) of the patients.

Conclusion
The results from this multicentric trial that investigated newly diagnosed MGMT promoter methylated IDH wildtype glioblastoma under real-life conditions indicate toxicity and survival estimates comparable to the CeTeG/NOA-09 trial. The use of TTFields for at least eight weeks in combination with this regimen was independently associated with extended progression-free and overall survival.