TY - THES A1 - Schuler, Patrick T1 - Lokalisation und Blockade der Serinprotease uPA im C6-Glioblastom-Modell der Ratte T1 - Lokalisation and Blockade of Serinprotease uPA in C6-Glioblastoma modell of the Rat N2 - Gegenstand dieser Doktorarbeit war die Beschreibung des Urokinaseplaminaktivators uPA im C6-Sphäroidmodell der Ratte und dessen Lokalisation in Bezug auf den Primärtumor. Das hierbei verwendete Tiermodell basiert auf der C6-Tumorzellreihe, welche durch Transfektion von Rattengliomzellen mit dem Vaskularisierungsfaktor VEGF entwickelt wurde. Die gesteigerte Expression von VEGF resultiert in einer stärkeren Vaskularisierung und einer erhöhten Wachstumsrate des Tumors. Im Vorfeld der Tumorimplantation konnte die Expression von uPA durch die C6-Tumorzellen mittels reverser RNA-Transkription und Polymerasekettenreaktion nachgewiesen werden. In vitro gelang der Nachweis von uPA im C6-Sphäroiden mittels Fluoreszenz-Färbung. Im Rahmen des Tierversuches wurden aus den Tumorzellen ca. 300µm große Sphäroide hergestellt, welche den Ratten in den Kortex des linken Frontallappens implantiert wurden und dort solide Hirntumoren bildeten. Die Versuchstiere wurden anschließend in zwei Gruppen aufgeteilt. Der Positivgruppe wurde täglich über einen Zeitraum von 19 bzw. 21 Tagen der Proteasehemmer WX-UK1 in die Bauchhöhle injiziert, die Kontrollgruppe erhielt ein Placebo. Nach Ablauf des Behandlungszeitraumes konnte an den explantierten Gehirnen mittels histochemischer Peroxidasefärbung die Protease uPA im Tumorgewebe nachgewiesen werden. Die Konzentration von uPA war besonders im invasionsaktiven Bereich des Tumors erhöht. Dieser entspricht der Randzone des soliden Tumors, sowie den distanzierten Zellnestern im gesunden Hirngewebe, welche als so genannte Invasionszone zusammengefasst werden. Die tragende Rolle von uPA bei der Invasion der Tumorzellen in das gesunde Hirngewebe konnte somit bestätigt werden. Die Messung von erhöhten uPA-Konzentrationen an der Basalmembran von Hirngefäßen korreliert mit Beobachtungen, dass die Tumorzellen entlang von Gefäßen und Plexus migrieren, aber nicht in der Lage sind, in das Gefäßlumen einzudringen. Der Nachweis der erfolgreichen orthotopen Sphäroidimplantation mittels MRT-Bildgebung der Hirntumoren unterstreicht den Vorteil der offenen Implantationstechnik gegenüber der Zellinjektion. Die peritoneale Verabreichung des Proteasehemmers WX-UK1 führte im Rahmen dieser Untersuchungen zu keiner signifikanten Reduktion des Tumorwachstums, welches mittels Volumenmessung im MRT dokumentiert wurde. Des Weiteren konnte keine Minderung der uPA-Konzentration in den Tumoren der Positivgruppe gegenüber der Kontrollgruppe gemessen werden. Neben der fehlenden Biodistribution des Wirkstoffes kommt hierfür auch eine mangelnde Spezifität von WX-UK1 für uPA oder ein alternativer Aktivierungsweg der Proteolyse innerhalb der Tumorzellen in Betracht. Diese Arbeit führt zur Weiterentwicklung des C6-Sphäroidmodells und unterstützt die zukünftige Entwicklung von Wirkstoffen gegen das Tumorwachstum auf Basis der anti-invasiven Therapie. N2 - Lokalisation and Blockade of Serinprotease uPA in Glioblastoma modell of the Rat KW - Glioblastom KW - uPA KW - Infiltration KW - Hirntumor KW - Ratte KW - glioblastoma KW - uPA KW - infiltration KW - braintumor KW - rat Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-18967 ER - TY - THES A1 - Keßler, Almuth Friederike T1 - Der Proteasomenaktivator PA28gamma bei der Tumorentstehung und seine Verbindung zur Stresssignalgebung und zur Zellzyklusregulation T1 - The proteasome activator PA28gamma in tumor development and its association to stress signaling and cell cycle regulation N2 - Das Glioblastom ist der häufigste hirneigene Tumor des Erwachsenen. Es ist hoch invasiv, stark proliferierend und mit einer schlechten Prognose assoziiert. Heutige Therapiean-sätze zielen, neben der möglichst vollständigen Resektion des Tumorgewebes, vor allem auf Apoptoseinduktion durch DNA-Schäden in Tumorzellen. Daher ist die Aufklärung der molekularen Grundlagen dieser Prozesse essentiell, um Verbesserungen bei den Behandlungsmöglichkeiten erzielen zu können. Der Proteasomenaktivator PA28γ wird im Hirngewebe stark exprimiert, über seine Funktion ist jedoch nur wenig bekannt. Er wurde als Interaktionspartner des Zellzyklus- und DNA-Schadensregulators Mad2b in einem Hefe Two-Hybrid Screen identifiziert. Im Rahmen dieser Arbeit wurde diese Wechselwirkung mittels eines GST-Pulldown Experimentes be-stätigt. Obwohl PA28γ in Verbindung mit der Zellproliferation gebracht wird, konnte in GBM-Zelllinien keine signifikante Änderung der Zellteilungsraten beobachtet werden. Allerdings unterstützte die vermehrte Expression von PA28γ die Apoptose. Um durch neue Interaktionspartner von PA28γ Hinweise auf dessen Funktion zu erhalten, wurde ein Hefe Two-Hybrid Screen durchgeführt: PA28gamma steuert den Abbau von p53 und verweist über die hier neu beschriebene Interaktion mit HIPK1 ebenfalls auf den programmierten Zelltod. Dieser pro-apoptotische Zusammen-hang wird unterstützt durch die Interaktion mit 1A6/DRIM-interacting protein. Die Inter-aktion der Sumo E2 Ligase Ubc9 mit PA28gamma war ein erster Hinweis für eine Sumoylierung des Proteasomenaktivators, die die PA28gamma Aktivität regulieren könnte. Gleichzeitig ist Ubc9, wie auch die E3-Ligase PIAS, im Zusammenhang mit Apoptose beschrieben worden. Diese Fragestellungen wurden in weiterführenden Arbeiten erforscht. Einen anderen Aspekt beleuchtet die Interaktion von PA28gammamit Catenin alpha. Durch diese Wechselwirkung könnte PA28gamma Einfluß auf Interzellulärkontakte nehmen. Gerade im Hin-blick auf das GBM, charakterisiert durch ausgeprägtes Migrations- und Invasionsverhal-ten, könnte die Regulation von Interzellulärkontakten von besonderer Bedeutung sein. Aufgrund der oben beschriebenen Eigenschaften von PA28gammasollte dieses Protein für eine Therapie mittels DNA-Schäden induzierter Apoptose erforscht werden. PA28gamma könnte bei diesen Vorgängen ein zentraler Faktor sein, dessen Manipulation die etablierten Therapieformen unterstützen und deren Wirkung verbessern. N2 - Glioblastoma multiforme is the most prevalent brain tumor in adults, being highly invasive and proliferative. The prognosis is poor. Contemporary treatment options include complete tumor resection, followed by induction of DNA-damage by chemotherapeutics and gamma irradiation to induce apoptosis in the tumor cells. To optimize these treatment options, a full knowlegde of the involved molecular pathways is essential. The proteasome activator PA28gamma is highly expressed in brain tissue. However, little is known about its function. It was found in a yeast two-hybrid screen as an interaction partner of Mad2b, a regulator of cell cylce function and DNA-damage response. This thesis confirmed this interaction in a GST-pulldown assay. Although PA28gamma has been associated with cell proliferation, there was no significant effect on proliferation rates of GBM-cell lines detectable. However, PA28gamma was able to induce apoptosis in these cells. A yeast two-hybrid screen was performed using PA28gamma, to detect new, additional interaction partners. The aim was to get better knowlegde about the function of PA28gamma by elucidating its signaling network. Ubc9, a SUMO E2 conjugating enzyme, was detected. The interaction with Ubc9 was a first indication for a sumoylation of PA28gamma which might be involved in the regulation of PA28gamma protein activity. Ubc9 has been described in conjunction with regulation of apoptosis. It is known that PA28gamma regulates p53-degradation. In addition, the yeast two-hybrid screen revealed an interaction with the proteins HIPK1 and 1A6/DRIM-interacting protein. Together these data strongly suggest an involvement of PA28gamma in the regulation of apoptosis. Another new interaction partner of PA28gamma was Catenin alpha, which points to a putative role of PA28gamma in the regulation of cell-cell-contacts. Since Glioblastoma multiforme display strong invasive characteristics, the regulation of intercellular contacts could be of special importance for the treatment. The established therapeutic means target DNA-damage to induce apoptosis of the tumor cells. In view of the suggested role of PA28gamma in regulation of apoptosis and cellular contacts, PA28gamma is worth further research to support the standard-therapy by manipulation of the PA28gamma activity. KW - Proteasomenaktivator KW - Tumorentstehung KW - Zellzyklusregulation KW - Glioblastom KW - Astrozytom KW - Cell cycle regulation KW - stress signaling KW - tumor development KW - glioblastoma KW - astocytoma Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-74469 ER - TY - JOUR A1 - Lapa, Constantin A1 - Lückerath, Katharina A1 - Kleinlein, Irene A1 - Monoranu, Camelia Maria A1 - Linsenmann, Thomas A1 - Kessler, Almuth F. A1 - Rudelius, Martina A1 - Kropf, Saskia A1 - Buck, Andreas K. A1 - Ernestus, Ralf-Ingo A1 - Wester, Hans-Jürgen A1 - Löhr, Mario A1 - Herrmann, Ken T1 - \(^{68}\)Ga-Pentixafor-PET/CT for Imaging of Chemokine Receptor 4 Expression in Glioblastoma JF - Theranostics N2 - Chemokine receptor-4 (CXCR4) has been reported to be overexpressed in glioblastoma (GBM) and to be associated with poor survival. This study investigated the feasibility of non-invasive CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using the radiolabelled chemokine receptor ligand \(^{68}\)Ga-Pentixafor. 15 patients with clinical suspicion on primary or recurrent glioblastoma (13 primary, 2 recurrent tumors) underwent \(^{68}\)Ga-Pentixafor-PET/CT for assessment of CXCR4 expression prior to surgery. O-(2-\(^{18}\)F-fluoroethyl)-L-tyrosine (\(^{18}\)F-FET) PET/CT images were available in 11/15 cases and were compared visually and semi-quantitatively (SUV\(_{max}\), SUV\(_{mean}\)). Tumor-to-background ratios (TBR) were calculated for both PET probes. \(^{68}\)Ga-Pentixafor-PET/CT results were also compared to histological CXCR4 expression on neuronavigated surgical samples. \(^{68}\)Ga-Pentixafor-PET/CT was visually positive in 13/15 cases with SUV\(_{mean}\) and SUV\(_{max}\) of 3.0±1.5 and 3.9±2.0 respectively. Respective values for \(^{18}\)F-FET were 4.4±2.0 (SUV\(_{mean}\)) and 5.3±2.3 (SUV\(_{max}\)). TBR for SUV\(_{mean}\) and SUV\(_{max}\) were higher for \(^{68}\)Ga-Pentixafor than for \(^{18}\)F-FET (SUV\(_{mean}\) 154.0±90.7 vs. 4.1±1.3; SUV\(_{max}\) 70.3±44.0 and 3.8±1.2, p<0.01), respectively. Histological analysis confirmed CXCR4 expression in tumor areas with high \(^{68}\)Ga-Pentixafor uptake; regions of the same tumor without apparent \(^{68}\)Ga-Pentixafor uptake showed no or low receptor expression. In this pilot study, \(^{68}\)Ga-Pentixafor retention has been observed in the vast majority of glioblastoma lesions and served as readout for non-invasive determination of CXCR4 expression. Given the paramount importance of the CXCR4/SDF-1 axis in tumor biology, \(^{68}\)Ga-Pentixafor-PET/CT might prove a useful tool for sensitive, non-invasive in-vivo quantification of CXCR4 as well as selection of patients who might benefit from CXCR4-directed therapy. KW - imaging KW - chemokine receptor-4 KW - glioblastoma KW - positron emission tomography/computed tomography KW - \(^{68}\)Ga-Pentixafor Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-168174 VL - 6 IS - 3 ER - TY - JOUR A1 - Dufner, Vera A1 - Kessler, Almuth Friederike A1 - Just, Larissa A1 - Hau, Peter A1 - Bumes, Elisabeth A1 - Pels, Hendrik Johannes A1 - Grauer, Oliver Martin A1 - Wiese, Bettina A1 - Löhr, Mario A1 - Jordan, Karin A1 - Strik, Herwig T1 - The emesis trial: depressive glioma patients are more affected by chemotherapy-induced nausea and vomiting JF - Frontiers in Neurology N2 - Purpose Glioma patients face a limited life expectancy and at the same time, they suffer from afflicting symptoms and undesired effects of tumor treatment. Apart from bone marrow suppression, standard chemotherapy with temozolomide causes nausea, emesis and loss of appetite. In this pilot study, we investigated how chemotherapy-induced nausea and vomiting (CINV) affects the patients' levels of depression and their quality of life. Methods In this prospective observational multicentre study (n = 87), nausea, emesis and loss of appetite were evaluated with an expanded MASCC questionnaire, covering 10 days during the first and the second cycle of chemotherapy. Quality of life was assessed with the EORTC QLQ-C30 and BN 20 questionnaire and levels of depression with the PHQ-9 inventory before and after the first and second cycle of chemotherapy. Results CINV affected a minor part of patients. If present, it reached its maximum at day 3 and decreased to baseline level not before day 8. Levels of depression increased significantly after the first cycle of chemotherapy, but decreased during the further course of treatment. Patients with higher levels of depression were more severely affected by CINV and showed a lower quality of life through all time-points. Conclusion We conclude that symptoms of depression should be perceived in advance and treated in order to avoid more severe side effects of tumor treatment. Additionally, in affected patients, delayed nausea was most prominent, pointing toward an activation of the NK1 receptor. We conclude that long acting antiemetics are necessary totreat temozolomide-induced nausea. KW - glioblastoma KW - chemotherapy KW - depression KW - nausea and emesis KW - quality of life Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-262859 SN - 1664-2295 VL - 13 ER - TY - JOUR A1 - Feldheim, Jonas A1 - Kessler, Almuth F. A1 - Feldheim, Julia J. A1 - Schulz, Ellina A1 - Wend, David A1 - Lazaridis, Lazaros A1 - Kleinschnitz, Christoph A1 - Glas, Martin A1 - Ernestus, Ralf-Ingo A1 - Brandner, Sebastian A1 - Monoranu, Camelia M. A1 - Löhr, Mario A1 - Hagemann, Carsten T1 - Effects of long-term temozolomide treatment on glioblastoma and astrocytoma WHO grade 4 stem-like cells JF - International Journal of Molecular Sciences N2 - Glioblastoma leads to a fatal course within two years in more than two thirds of patients. An essential cornerstone of therapy is chemotherapy with temozolomide (TMZ). The effect of TMZ is counteracted by the cellular repair enzyme O\(^6\)-methylguanine-DNA methyltransferase (MGMT). The MGMT promoter methylation, the main regulator of MGMT expression, can change from primary tumor to recurrence, and TMZ may play a significant role in this process. To identify the potential mechanisms involved, three primary stem-like cell lines (one astrocytoma with the mutation of the isocitrate dehydrogenase (IDH), CNS WHO grade 4 (HGA)), and two glioblastoma (IDH-wildtype, CNS WHO grade 4) were treated with TMZ. The MGMT promoter methylation, migration, proliferation, and TMZ-response of the tumor cells were examined at different time points. The strong effects of TMZ treatment on the MGMT methylated cells were observed. Furthermore, TMZ led to a loss of the MGMT promoter hypermethylation and induced migratory rather than proliferative behavior. Cells with the unmethylated MGMT promoter showed more aggressive behavior after treatment, while HGA cells reacted heterogenously. Our study provides further evidence to consider the potential adverse effects of TMZ chemotherapy and a rationale for investigating potential relationships between TMZ treatment and change in the MGMT promoter methylation during relapse. KW - glioblastoma KW - astrocytoma KW - IDH KW - MGMT KW - therapy KW - temozolomide KW - cancer stem cells Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284417 SN - 1422-0067 VL - 23 IS - 9 ER - TY - JOUR A1 - Schulz, Ellina A1 - Mawamba, Viviane A1 - Löhr, Mario A1 - Hagemann, Carsten A1 - Friedrich, Alexandra A1 - Schatzschneider, Ulrich T1 - Structure–activity relations of Pd(II) and Pt(II) thiosemicarbazone complexes on different human glioblastoma cell lines JF - Zeitschrift für Anorganische und Allgemeine Chemie N2 - Ten thiosemicarbazone ligands obtained by condensation of pyridine-2-carbaldehyde, quinoline-2-carbaldehyde, 2-acetylpyridine, 2-acetylquinoline, or corresponding 2-pyridyl ketones with thiosemicarbazides RNHC(S)NHNH\(_{2}\) and R=CH\(_{3}\), C\(_{6}\)H\(_{5}\) were prepared in good yield. The reaction of [PdCl\(_{2}\)(cod)] with cod=1,5-cyclooctadiene or K\(_{2}\)[PtCl\(_{4}\)] resulted in a total of 17 Pd(II) and Pt(II) complexes isolated in excellent purity, as demonstrated by \(^{1}\)H, \(^{13}\)C, and, where applicable, \(^{195\)Pt NMR spectroscopy combined with CHNS analysis. The cytotoxicity of the title compounds was studied on four human glioblastoma cell lines (GaMG, U87, U138, and U343). The most active compound, with a Pd(II) metal centre, a 2-quinolinyl ring, and methyl groups on both the proximal C and distal N atoms exhibited an EC\(_{50}\) value of 2.1 μM on the GaMG cell lines, thus being slightly more active than cisplatin (EC\(_{50}\) 3.4 μM) and significantly more potent than temozolomide (EC\(_{50}\) 67.1 μM). Surprisingly, the EC\(_{50}\) values were inversely correlated with the lipophilicity, as determined with the “shake-flask method”, and decreased with the length of the alkyl substituents (C\(_{1}\)>C\(_{8}\)>C\(_{10}\)). Correlation with the different structural motifs showed that for the most promising anticancer activity, a maximum of two aromatic rings (either quinolinyl or pyridyl plus phenyl) combined with one methyl group are favoured and the Pd(II) complexes are slightly more potent than their Pt(II) analogues. KW - glioblastoma KW - platinum KW - palladium KW - thiosemicarbazone KW - anticancer activity Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318281 SN - 0044-2313 VL - 648 IS - 12 ER - TY - JOUR A1 - Löhr, Mario A1 - Härtig, Wolfgang A1 - Schulze, Almut A1 - Kroiß, Matthias A1 - Sbiera, Silviu A1 - Lapa, Constantin A1 - Mages, Bianca A1 - Strobel, Sabrina A1 - Hundt, Jennifer Elisabeth A1 - Bohnert, Simone A1 - Kircher, Stefan A1 - Janaki-Raman, Sudha A1 - Monoranu, Camelia-Maria T1 - SOAT1: A suitable target for therapy in high-grade astrocytic glioma? JF - International Journal of Molecular Sciences N2 - Targeting molecular alterations as an effective treatment for isocitrate dehydrogenase-wildtype glioblastoma (GBM) patients has not yet been established. Sterol-O-Acyl Transferase 1 (SOAT1), a key enzyme in the conversion of endoplasmic reticulum cholesterol to esters for storage in lipid droplets (LD), serves as a target for the orphan drug mitotane to treat adrenocortical carcinoma. Inhibition of SOAT1 also suppresses GBM growth. Here, we refined SOAT1-expression in GBM and IDH-mutant astrocytoma, CNS WHO grade 4 (HGA), and assessed the distribution of LD in these tumors. Twenty-seven GBM and three HGA specimens were evaluated by multiple GFAP, Iba1, IDH1 R132H, and SOAT1 immunofluorescence labeling as well as Oil Red O staining. To a small extent SOAT1 was expressed by tumor cells in both tumor entities. In contrast, strong expression was observed in glioma-associated macrophages. Triple immunofluorescence labeling revealed, for the first time, evidence for SOAT1 colocalization with Iba1 and IDH1 R132H, respectively. Furthermore, a notable difference in the amount of LD between GBM and HGA was observed. Therefore, SOAT1 suppression might be a therapeutic option to target GBM and HGA growth and invasiveness. In addition, the high expression in cells related to neuroinflammation could be beneficial for a concomitant suppression of protumoral microglia/macrophages. KW - SOAT1 KW - glioblastoma KW - astrocytoma KW - IDH1/2 KW - lipid droplets KW - mitotane KW - targeted therapy Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284178 SN - 1422-0067 VL - 23 IS - 7 ER - TY - JOUR A1 - Nickl, Vera A1 - Schulz, Ellina A1 - Salvador, Ellaine A1 - Trautmann, Laureen A1 - Diener, Leopold A1 - Kessler, Almuth F. A1 - Monoranu, Camelia M. A1 - Dehghani, Faramarz A1 - Ernestus, Ralf-Ingo A1 - Löhr, Mario A1 - Hagemann, Carsten T1 - Glioblastoma-derived three-dimensional ex vivo models to evaluate effects and efficacy of Tumor Treating Fields (TTFields) JF - Cancers N2 - Simple Summary In glioblastoma, tumor recurrence is inevitable and the prognosis of patients is poor, despite multidisciplinary treatment approaches involving surgical resection, radiotherapy and chemotherapy. Recently, Tumor Treating Fields (TTFields) have been added to the therapeutic set-up. These alternating electric fields are applied to glioblastoma at 200 kHz frequency via arrays placed on the shaved scalp of patients. Patients show varying response to this therapy. Molecular effects of TTFields have been investigated largely in cell cultures and animal models, but not in patient tissue samples. Acquisition of matched treatment-naïve and recurrent patient tissues is a challenge. Therefore, we suggest three reliable patient-derived three-dimensional ex vivo models (primary cells grown as microtumors on murine organotypic hippocampal slices, organoids and tumor slice cultures) which may facilitate prediction of patients’ treatment responses and provide important insights into clinically relevant cellular and molecular alterations under TTFields. Abstract Glioblastoma (GBM) displays a wide range of inter- and intra-tumoral heterogeneity contributing to therapeutic resistance and relapse. Although Tumor Treating Fields (TTFields) are effective for the treatment of GBM, there is a lack of ex vivo models to evaluate effects on patients’ tumor biology or to screen patients for treatment efficacy. Thus, we adapted patient-derived three-dimensional tissue culture models to be compatible with TTFields application to tissue culture. Patient-derived primary cells (PDPC) were seeded onto murine organotypic hippocampal slice cultures (OHSC), and microtumor development with and without TTFields at 200 kHz was observed. In addition, organoids were generated from acute material cultured on OHSC and treated with TTFields. Lastly, the effect of TTFields on expression of the Ki67 proliferation marker was evaluated on cultured GBM slices. Microtumors exhibited increased sensitivity towards TTFields compared to monolayer cell cultures. TTFields affected tumor growth and viability, as the size of microtumors and the percentage of Ki67-positive cells decreased after treatment. Nevertheless, variability in the extent of the response was preserved between different patient samples. Therefore, these pre-clinical GBM models could provide snapshots of the tumor to simulate patient treatment response and to investigate molecular mechanisms of response and resistance. KW - glioblastoma KW - Tumor Treating Fields (TTFields) KW - organotypic hippocampal slice cultures (OHSC) KW - organoids KW - tumor slice cultures KW - 3D ex vivo models Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290340 SN - 2072-6694 VL - 14 IS - 21 ER - TY - THES A1 - Herbinger, Anna Maria T1 - Wirkungsverstärkung von Vincristin und Paclitaxel auf Glioblastomzellen durch TTFields T1 - Enhancement of effect of vincristine and paclitaxel on glioblastoma cells by TTFields N2 - Das Glioblastom (GBM) ist der häufigste maligne primäre Hirntumor im Erwachsenenalter und geht mit einer infausten Prognose einher. Die Standardtherapie bei Erstdiagnose besteht aus Tumorresektion gefolgt von kombinierter Radiochemotherapie mit Temozolomid nach Stupp-Schema. Eine neue Therapieoption stellen die Tumor Treating Fields (TTFields) in Form lokal applizierter elektrischer Wechselfelder dar. Mit dem Einsatz der TTFields kann durch Störung der mitotischen Abläufe die Zellproliferation von Tumorzellen gehemmt und dadurch das Gesamtüberleben im Vergleich zur alleinigen Radiochemotherapie nachweislich deutlich verlängert werden. Auch verschiedene Chemotherapeutika, die bereits klinisch eingesetzt werden, greifen in den Ablauf der Mitose ein. So auch die Zytostatika Vincristin (VIN) und Paclitaxel (PTX), die durch einen gegensätzlichen Mechanismus durch Destabilisierung bzw. Stabilisierung von Mikrotubulistrukturen ihre Wirkung entfalten. Die Frage, ob eine Verstärkung dieser Wirkung durch den kombinierten Einsatz mit TTFields erreicht werden kann, wurde in dieser Arbeit an den beiden GBM-Zelllinien U87 und GaMG untersucht. Zunächst wurde mit dem xCELLigence-Systems über eine Real-Time-Impedanzmessung für diese beiden Chemotherapeutika jeweils die mittlere effektive Dosis (EC50-Wert), bei der ein halbmaximaler Effekt auftritt, spezifisch für jede Zelllinie bestimmt. Diese betrug bei VIN durchschnittlich 200nM für die Zelllinie U87 bzw. 20nM für die Zelllinie GaMG und lag für PTX bei 60nM für beide Zelllinien. Mit diesen Dosierungen wurden die beiden Zelllinien allein und in Kombination mit TTFields über 72h behandelt. Anschließend wurde die Zellproliferation analysiert und mit unbehandelten Tumorzellen verglichen. Während jeder Behandlungsarm einzeln eine signifikante Wirkung gegenüber der unbehandelten Vergleichsgruppe zeigte, hatte weder die Kombination von TTFields mit VIN noch mit PTX in den untersuchten Dosierungen einen zusätzlichen signifikanten Nutzen. Es besteht weiterer Forschungsbedarf zum kombinierten Einsatz von TTFields mit anderen Therapieformen. N2 - Glioblastoma (GBM) is the most common malignant primary brain tumor in adults and is associated with an infavorable prognosis. Standard therapy at initial diagnosis consists of tumor resection followed by combined radiochemotherapy with temozolomide according to the Stupp regimen. Tumor Treating Fields (TTFields) in the form of locally applied alternating electric fields represent a new therapeutic option. With the use of TTFields, cell proliferation of tumor cells can be inhibited by interfering with mitotic processes, which has been shown to significantly prolong overall survival compared to radiochemotherapy alone. Various chemotherapeutic treatments already in clinical use also interfere with mitotic processes. This is also the case with the cytostatic drugs vincristine (VIN) and paclitaxel (PTX), which exert their effects by an opposing mechanism through destabilization and stabilization of microtubule structures. The question whether an enhancement of this effect can be achieved by combined use with TTFields was investigated in this work using the two GBM cell lines U87 and GaMG. First, using the xCELLigence system via real-time impedance measurement, the mean effective dose (EC50-value) at which a half-maximal effect occurs was determined for each of these two chemotherapeutic agents specifically for each cell line. This was averaged 200nM for VIN for the U87 cell line and 20nM for the GaMG cell line, and was 60nM for PTX for both cell lines. The two cell lines were treated with these doses alone and in combination with TTFields for 72h. Cell proliferation was then analyzed and compared to untreated tumor cells. While each treatment individually showed a significant effect compared with the untreated control group, neither the combination of TTFields with VIN nor with PTX had any additional significant benefit at the doses studied. Further research is needed on the combined use of TTFields with other therapies. KW - Tumortherapiefelder KW - Vincristin KW - Taxol KW - TTFields KW - Paclitaxel KW - glioblastoma KW - tumor treating fields KW - vincristine KW - paclitaxel KW - Glioblastom Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-329836 ER - TY - JOUR A1 - Feldheim, Jonas A1 - Kessler, Almuth F. A1 - Feldheim, Julia J. A1 - Schmitt, Dominik A1 - Oster, Christoph A1 - Lazaridis, Lazaros A1 - Glas, Martin A1 - Ernestus, Ralf-Ingo A1 - Monoranu, Camelia M. A1 - Löhr, Mario A1 - Hagemann, Carsten T1 - BRMS1 in gliomas — an expression analysis JF - Cancers N2 - The metastatic suppressor BRMS1 interacts with critical steps of the metastatic cascade in many cancer entities. As gliomas rarely metastasize, BRMS1 has mainly been neglected in glioma research. However, its interaction partners, such as NFκB, VEGF, or MMPs, are old acquaintances in neurooncology. The steps regulated by BRMS1, such as invasion, migration, and apoptosis, are commonly dysregulated in gliomas. Therefore, BRMS1 shows potential as a regulator of glioma behavior. By bioinformatic analysis, in addition to our cohort of 118 specimens, we determined BRMS1 mRNA and protein expression as well as its correlation with the clinical course in astrocytomas IDH mutant, CNS WHO grade 2/3, and glioblastoma IDH wild-type, CNS WHO grade 4. Interestingly, we found BRMS1 protein expression to be significantly decreased in the aforementioned gliomas, while BRMS1 mRNA appeared to be overexpressed throughout. This dysregulation was independent of patients’ characteristics or survival. The protein and mRNA expression differences cannot be finally explained at this stage. However, they suggest a post-transcriptional dysregulation that has been previously described in other cancer entities. Our analyses present the first data on BRMS1 expression in gliomas that can provide a starting point for further investigations. KW - glioblastoma KW - metastasis KW - suppressor KW - behavior KW - mRNA KW - protein Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319225 SN - 2072-6694 VL - 15 IS - 11 ER - TY - JOUR A1 - Nickl, Vera A1 - Eck, Juliana A1 - Goedert, Nicolas A1 - Hübner, Julian A1 - Nerreter, Thomas A1 - Hagemann, Carsten A1 - Ernestus, Ralf-Ingo A1 - Schulz, Tim A1 - Nickl, Robert Carl A1 - Keßler, Almuth Friederike A1 - Löhr, Mario A1 - Rosenwald, Andreas A1 - Breun, Maria A1 - Monoranu, Camelia Maria T1 - Characterization and optimization of the tumor microenvironment in patient-derived organotypic slices and organoid models of glioblastoma JF - Cancers N2 - While glioblastoma (GBM) is still challenging to treat, novel immunotherapeutic approaches have shown promising effects in preclinical settings. However, their clinical breakthrough is hampered by complex interactions of GBM with the tumor microenvironment (TME). Here, we present an analysis of TME composition in a patient-derived organoid model (PDO) as well as in organotypic slice cultures (OSC). To obtain a more realistic model for immunotherapeutic testing, we introduce an enhanced PDO model. We manufactured PDOs and OSCs from fresh tissue of GBM patients and analyzed the TME. Enhanced PDOs (ePDOs) were obtained via co-culture with PBMCs (peripheral blood mononuclear cells) and compared to normal PDOs (nPDOs) and PT (primary tissue). At first, we showed that TME was not sustained in PDOs after a short time of culture. In contrast, TME was largely maintained in OSCs. Unfortunately, OSCs can only be cultured for up to 9 days. Thus, we enhanced the TME in PDOs by co-culturing PDOs and PBMCs from healthy donors. These cellular TME patterns could be preserved until day 21. The ePDO approach could mirror the interaction of GBM, TME and immunotherapeutic agents and may consequently represent a realistic model for individual immunotherapeutic drug testing in the future. KW - glioblastoma KW - organoids KW - slice culture KW - tumormicroenvironment Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319249 SN - 2072-6694 VL - 15 IS - 10 ER -