Güliz Acker1, Julia Zollfrank2, Claudius Jelgersma2, Melina Nieminen-Kelhä2, Irina Kremenetskaia2, Susanne Mueller3, Adnan Ghori2, Peter Vajkoczy4, Susan Brandenburg2. 1. Department of Neurosurgery and Experimental Neurosurgery, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany; Berlin Institute of Health (BIH), Anna-Louisa-Karsch-Str. 2, 10178, Berlin, Germany. 2. Department of Neurosurgery and Experimental Neurosurgery, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany. 3. Department of Neurology and Experimental Neurology, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany. 4. Department of Neurosurgery and Experimental Neurosurgery, Charité Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany. Electronic address: peter.vajkoczy@charite.de.
Abstract
OBJECTIVE: Besides VEGF, alternative signalling via CXCR2 and its ligands CXCL2/CXCL8 is a crucial part of angiogenesis in glioblastoma. Our aim was to understand the role of CXCR2 for glioma biology and elucidate the therapeutic potential of its specific inhibition. METHODS: GL261 glioma cells were implanted intracranially in syngeneic mice. The 14 or 7 days of local or systemic treatment with CXCR2-antagonist (SB225002) was initiated early on the day of tumour cell implantation or delayed after 14 days of tumour growth. Glioma volume was verified using MRI before and after treatment. Immunofluorescence staining was used to investigate tumour progression, angiogenesis and microglial behaviour. Furthermore, in vitro assays and gene expression analyses of glioma and endothelial cells were performed to validate inhibitor activity. RESULTS: CXCR2-blocking led to significantly reduced glioma volumes of around 50% after early and delayed local treatments. The treated tumours were comparable with controls regarding invasiveness, proliferation and apoptotic cell activity. Furthermore, no differences in CXCR2/CXCL2 expression were observed. However, immunostaining revealed reduction in vessel density and accumulation of microglia/macrophages, whereas interaction of these myeloid cells with tumour vessels was enhanced. In vitro analyses of the CXCR2-antagonist showed its direct impact on proliferation of glioma and endothelial cells if used at higher concentrations. In addition, expression of CXCR2/CXCL2 signalling genes was increased in both cell types by SB225002, but VEGF-relevant genes were unaffected. CONCLUSION: The CXCR2-antagonist inhibited glioma growth during tumour initiation and progression, whereas treatment was well-tolerated by the recipients. Thus, the CXCR2/CXCL2 signalling represents a promising therapeutic target in glioma.
OBJECTIVE: Besides VEGF, alternative signalling via CXCR2 and its ligands CXCL2/CXCL8 is a crucial part of angiogenesis in glioblastoma. Our aim was to understand the role of CXCR2 for glioma biology and elucidate the therapeutic potential of its specific inhibition. METHODS:GL261glioma cells were implanted intracranially in syngeneic mice. The 14 or 7 days of local or systemic treatment with CXCR2-antagonist (SB225002) was initiated early on the day of tumour cell implantation or delayed after 14 days of tumour growth. Glioma volume was verified using MRI before and after treatment. Immunofluorescence staining was used to investigate tumour progression, angiogenesis and microglial behaviour. Furthermore, in vitro assays and gene expression analyses of glioma and endothelial cells were performed to validate inhibitor activity. RESULTS:CXCR2-blocking led to significantly reduced glioma volumes of around 50% after early and delayed local treatments. The treated tumours were comparable with controls regarding invasiveness, proliferation and apoptotic cell activity. Furthermore, no differences in CXCR2/CXCL2 expression were observed. However, immunostaining revealed reduction in vessel density and accumulation of microglia/macrophages, whereas interaction of these myeloid cells with tumour vessels was enhanced. In vitro analyses of the CXCR2-antagonist showed its direct impact on proliferation of glioma and endothelial cells if used at higher concentrations. In addition, expression of CXCR2/CXCL2 signalling genes was increased in both cell types by SB225002, but VEGF-relevant genes were unaffected. CONCLUSION: The CXCR2-antagonist inhibited glioma growth during tumour initiation and progression, whereas treatment was well-tolerated by the recipients. Thus, the CXCR2/CXCL2 signalling represents a promising therapeutic target in glioma.
Authors: Md Huzzatul Mursalin; Phillip S Coburn; Frederick C Miller; Erin T Livingston; Roger Astley; Michelle C Callegan Journal: Invest Ophthalmol Vis Sci Date: 2021-11-01 Impact factor: 4.799
Authors: Ruth M Urbantat; Anne Blank; Irina Kremenetskaia; Peter Vajkoczy; Güliz Acker; Susan Brandenburg Journal: Int J Mol Sci Date: 2021-03-05 Impact factor: 5.923