@article{SalvadorBurekLoehretal.2021, author = {Salvador, Ellaine and Burek, Malgorzata and L{\"o}hr, Mario and Nagai, Michiaki and Hagemann, Carsten and F{\"o}rster, Carola Y.}, title = {Senescence and associated blood-brain barrier alterations in vitro}, series = {Histochemistry and Cell Biology}, volume = {156}, journal = {Histochemistry and Cell Biology}, number = {3}, issn = {1432-119X}, doi = {10.1007/s00418-021-01992-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-267435}, pages = {283-292}, year = {2021}, abstract = {Progressive deterioration of the central nervous system (CNS) is commonly associated with aging. An important component of the neurovasculature is the blood-brain barrier (BBB), majorly made up of endothelial cells joined together by intercellular junctions. The relationship between senescence and changes in the BBB has not yet been thoroughly explored. Moreover, the lack of in vitro models for the study of the mechanisms involved in those changes impede further and more in-depth investigations in the field. For this reason, we herein present an in vitro model of the senescent BBB and an initial attempt to identify senescence-associated alterations within.}, language = {en} } @article{FeldheimKesslerSchmittetal.2020, author = {Feldheim, Jonas and Kessler, Almuth F. and Schmitt, Dominik and Salvador, Ellaine and Monoranu, Camelia M. and Feldheim, Julia J. and Ernestus, Ralf-Ingo and L{\"o}hr, Mario and Hagemann, Carsten}, title = {Ribosomal Protein S27/Metallopanstimulin-1 (RPS27) in Glioma — A New Disease Biomarker?}, series = {Cancers}, volume = {12}, journal = {Cancers}, number = {5}, issn = {2072-6694}, doi = {10.3390/cancers12051085}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-203648}, year = {2020}, abstract = {Despite its significant overexpression in several malignant neoplasms, the expression of RPS27 in the central nervous system (CNS) is widely unknown. We identified the cell types expressing RPS27 in the CNS under normal and disease conditions. We acquired specimens of healthy brain (NB), adult pilocytic astrocytoma (PA) World Health Organization (WHO) grade I, anaplastic PA WHO grade III, gliomas WHO grade II/III with or without isocitrate dehydrogenase (IDH) mutation, and glioblastoma multiforme (GBM). RPS27 protein expression was examined by immunohistochemistry and double-fluorescence staining and its mRNA expression quantified by RT-PCR. Patients' clinical and tumor characteristics were collected retrospectively. RPS27 protein was specifically expressed in tumor cells and neurons, but not in healthy astrocytes. In tumor tissue, most macrophages were positive, while this was rarely the case in inflamed tissue. Compared to NB, RPS27 mRNA was in mean 6.2- and 8.8-fold enhanced in gliomas WHO grade II/III with (p < 0.01) and without IDH mutation (p = 0.01), respectively. GBM displayed a 4.6-fold increased mean expression (p = 0.02). Although RPS27 expression levels did not affect the patients' survival, their association with tumor cells and tumor-associated macrophages provides a rationale for a future investigation of a potential function during gliomagenesis and tumor immune response.}, language = {en} } @article{SalvadorKesslerDomroeseetal.2022, author = {Salvador, Ellaine and Kessler, Almuth F. and Domr{\"o}se, Dominik and H{\"o}rmann, Julia and Schaeffer, Clara and Giniunaite, Aiste and Burek, Malgorzata and Tempel-Brami, Catherine and Voloshin, Tali and Volodin, Alexandra and Zeidan, Adel and Giladi, Moshe and Ernestus, Ralf-Ingo and L{\"o}hr, Mario and F{\"o}rster, Carola Y. and Hagemann, Carsten}, title = {Tumor Treating Fields (TTFields) reversibly permeabilize the blood-brain barrier in vitro and in vivo}, series = {Biomolecules}, volume = {12}, journal = {Biomolecules}, number = {10}, issn = {2218-273X}, doi = {10.3390/biom12101348}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288057}, year = {2022}, abstract = {Despite the availability of numerous therapeutic substances that could potentially target CNS disorders, an inability of these agents to cross the restrictive blood-brain barrier (BBB) limits their clinical utility. Novel strategies to overcome the BBB are therefore needed to improve drug delivery. We report, for the first time, how Tumor Treating Fields (TTFields), approved for glioblastoma (GBM), affect the BBB's integrity and permeability. Here, we treated murine microvascular cerebellar endothelial cells (cerebEND) with 100-300 kHz TTFields for up to 72 h and analyzed the expression of barrier proteins by immunofluorescence staining and Western blot. In vivo, compounds normally unable to cross the BBB were traced in healthy rat brain following TTFields administration at 100 kHz. The effects were analyzed via MRI and immunohistochemical staining of tight-junction proteins. Furthermore, GBM tumor-bearing rats were treated with paclitaxel (PTX), a chemotherapeutic normally restricted by the BBB combined with TTFields at 100 kHz. The tumor volume was reduced with TTFields plus PTX, relative to either treatment alone. In vitro, we demonstrate that TTFields transiently disrupted BBB function at 100 kHz through a Rho kinase-mediated tight junction claudin-5 phosphorylation pathway. Altogether, if translated into clinical use, TTFields could represent a novel CNS drug delivery strategy.}, language = {en} } @article{SalvadorKoepplHoermannetal.2023, author = {Salvador, Ellaine and K{\"o}ppl, Theresa and H{\"o}rmann, Julia and Sch{\"o}nh{\"a}rl, Sebastian and Bugaeva, Polina and Kessler, Almuth F. and Burek, Malgorzata and Ernestus, Ralf-Ingo and L{\"o}hr, Mario and Hagemann, Carsten}, title = {Tumor Treating Fields (TTFields) induce cell junction alterations in a human 3D in vitro model of the blood-brain barrier}, series = {Pharmaceutics}, volume = {15}, journal = {Pharmaceutics}, number = {1}, issn = {1999-4923}, doi = {10.3390/pharmaceutics15010185}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304830}, year = {2023}, abstract = {In a recent study, we showed in an in vitro murine cerebellar microvascular endothelial cell (cerebEND) model as well as in vivo in rats that Tumor-Treating Fields (TTFields) reversibly open the blood-brain barrier (BBB). This process is facilitated by delocalizing tight junction proteins such as claudin-5 from the membrane to the cytoplasm. In investigating the possibility that the same effects could be observed in human-derived cells, a 3D co-culture model of the BBB was established consisting of primary microvascular brain endothelial cells (HBMVEC) and immortalized pericytes, both of human origin. The TTFields at a frequency of 100 kHz administered for 72 h increased the permeability of our human-derived BBB model. The integrity of the BBB had already recovered 48 h post-TTFields, which is earlier than that observed in cerebEND. The data presented herein validate the previously observed effects of TTFields in murine models. Moreover, due to the fact that human cell-based in vitro models more closely resemble patient-derived entities, our findings are highly relevant for pre-clinical studies.}, language = {en} } @article{NicklSchulzSalvadoretal.2022, author = {Nickl, Vera and Schulz, Ellina and Salvador, Ellaine and Trautmann, Laureen and Diener, Leopold and Kessler, Almuth F. and Monoranu, Camelia M. and Dehghani, Faramarz and Ernestus, Ralf-Ingo and L{\"o}hr, Mario and Hagemann, Carsten}, title = {Glioblastoma-derived three-dimensional ex vivo models to evaluate effects and efficacy of Tumor Treating Fields (TTFields)}, series = {Cancers}, volume = {14}, journal = {Cancers}, number = {21}, issn = {2072-6694}, doi = {10.3390/cancers14215177}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290340}, year = {2022}, abstract = {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-na{\"i}ve 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.}, language = {en} }