title: A versatile ex vivo technique for assaying tumor angiogenesis and microglia in the brain.
abstract: Primary brain tumors are hallmarked for their destructive activity on the microenvironment and vasculature. However, solely few experimental techniques exist to access the tumor microenvironment under anatomical intact conditions with remaining cellular and extracellular composition. Here, we detail an ex vivo vascular glioma impact method (VOGIM) to investigate the influence of gliomas and chemotherapeutics on the tumor microenvironment and angiogenesis under conditions that closely resemble the in vivo situation. We generated organotypic brain slice cultures from rats and transgenic mice and implanted glioma cells expressing fluorescent reporter proteins. In the VOGIM, tumor-induced vessels presented the whole range of vascular pathologies and tumor zones as found in human primary brain tumor specimens. In contrast, non-transformed cells such as primary astrocytes do not alter the vessel architecture. Vascular characteristics with vessel branching, junctions and vessel meshes are quantitatively assessable as well as the peritumoral zone. In particular, the VOGIM resembles the brain tumor microenvironment with alterations of neurons, microglia and cell survival. Hence, this method allows live cell monitoring of virtually any fluorescence-reporter expressing cell. We further analyzed the vasculature and microglia under the influence of tumor cells and chemotherapeutics such as Temozolamide (Temodal/Temcad®). Noteworthy, temozolomide normalized vasculare junctions and branches as well as microglial distribution in tumor-implanted brains. Moreover, VOGIM can be facilitated for implementing the 3Rs in experimentations. In summary, the VOGIM represents a versatile and robust technique which allows the assessment of the brain tumor microenvironment with parameters such as angiogenesis, neuronal cell death and microglial activity at the morphological and quantitative level.
authors.affiliation: Laboratory for Translational Neurooncology, Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
authors.forename: Ali
authors.initials: A
authors.lastname: Ghoochani
authors.affiliation: Laboratory for Translational Neurooncology, Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
authors.forename: Eduard
authors.initials: E
authors.lastname: Yakubov
authors.affiliation: Laboratory for Translational Neurooncology, Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Sehm
authors.affiliation: Laboratory for Translational Neurooncology, Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Laboratory for Translational Neurooncology, Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hock
authors.affiliation: Laboratory for Translational Neurooncology, Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Buchfelder
authors.affiliation: Laboratory for Translational Neurooncology, Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
authors.forename: Ilker Y
authors.initials: IY
authors.lastname: Eyüpoglu
authors.affiliation: Laboratory for Translational Neurooncology, Department of Neurosurgery, Universitätsklinikum Erlangen, Friedrich Alexander University of Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany.
authors.forename: Nicolai E
authors.initials: NE
authors.lastname: Savaskan
mesh_terms: D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D001932:Brain Neoplasms / Q000098:blood supply* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000235:genetics; D003606:Dacarbazine / Q000031:analogs & derivatives / Q000494:pharmacology; D005910:Glioma / Q000098:blood supply* / Q000473:pathology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008822:Mice, Transgenic; D017628:Microglia / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging* / Q000235:genetics / Q000378:metabolism; D009924:Organ Culture Techniques / Q000379:methods*; D017208:Rats, Wistar; D015203:Reproducibility of Results; D000077204:Temozolomide; D059016:Tumor Microenvironment / Q000187:drug effects / Q000235:genetics
chemical_list: D018906:Antineoplastic Agents, Alkylating; D049452:Green Fluorescent Proteins; D003606:Dacarbazine; D000077204:Temozolomide
keywords: angiogenesis; ex vivo; glioblastoma; neuronal cell death; slice culture