gms | German Medical Science

73. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
Joint Meeting mit der Griechischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

29.05. - 01.06.2022, Köln

Article

Send article

Tumour Treating Fields (TTFields) promotes Rho kinase-dependent phosphorylation of the tight junction protein claudin-5

Die TTFields-induzierte Phosphorylierung des Tight-Junction-Proteins Claudin-5 ist abhängig von Rho-Kinase

Meeting Abstract

Search Medline for

  • presenting/speaker Ellaine Salvador - Universitätsklinikum Würzburg, Klinik und Poliklinik für Neurochirurgie, Sektion Experimentelle Neurochirurgie, Würzburg, Deutschland
  • Almuth F. Keßler - Universitätsklinikum Würzburg, Klinik und Poliklinik für Neurochirurgie, Sektion Experimentelle Neurochirurgie, Würzburg, Deutschland
  • Malgorzata Burek - Universitätsklinikum Würzburg, Experimentelle Anästhesiologie und molekulare Medizin, Würzburg, Deutschland
  • Catherine Tempel Brami - NovoCure Ltd., Haifa, Israel
  • Tali Voloshin-Sela - NovoCure Ltd., Haifa, Israel
  • Alexandra Volodin - NovoCure Ltd., Haifa, Israel
  • Zeidan Adel - NovoCure Ltd., Haifa, Israel
  • Moshe Giladi - NovoCure Ltd., Haifa, Israel
  • Ralf-Ingo Ernestus - Universitätsklinikum Würzburg, Neurochirurgische Klinik und Poliklinik, Würzburg, Deutschland
  • Mario Löhr - Universitätsklinikum Würzburg, Neurochirurgische Klinik und Poliklinik, Würzburg, Deutschland
  • Carola Förster - Universitätsklinikum Würzburg, Experimentelle Anästhesiologie und molekulare Medizin, Würzburg, Deutschland
  • Carsten Hagemann - Universitätsklinikum Würzburg, Klinik und Poliklinik für Neurochirurgie, Sektion Experimentelle Neurochirurgie, Würzburg, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 73. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Griechischen Gesellschaft für Neurochirurgie. Köln, 29.05.-01.06.2022. Düsseldorf: German Medical Science GMS Publishing House; 2022. DocV145

doi: 10.3205/22dgnc143, urn:nbn:de:0183-22dgnc1430

Published: May 25, 2022

© 2022 Salvador et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.

Outline

Text

Objective: Tumor Treating Fields (TTFields) are alternating electrical fields that are approved and effective for glioblastoma therapy with a frequency of 200 kHz. At a frequency of 100 kHz, we have previously shown that TTFields can transiently open the blood-brain barrier (BBB) in vitro and in vivo by delocalizing the tight junction protein claudin-5.

It is known that TTFields reorganize the microtubule network, which leads to the initiation of the guanine nucleotide exchange factor (GEF) H1 / Rho / Rho-associated protein kinases (ROCK) signaling pathway in cancer cells. To determine whether the TTFields-induced delocalization of claudin-5 is mediated by this pathway, we examined changes in the phosphorylation of GEF-H1 and claudin-5 in immortalized brain microvascular endothelial cells (cerebEND).

Methods: After treatment with 100 kHz TTFields for 10-60 minutes, cerebEND were lysed for Western blot analysis with antibodies against GEF-H1, as well as phosphorylated GEF-H1 and claudin-5. ROCK activity in the cells was measured using a ROCK activity assay kit. The cells were also treated with 10 μM of the ROCK inhibitor fasudil in combination with 100 kHz TTFields for 72 h and then stained with anti-claudin-5 antibodies for immunofluorescence microscopy.

Results: TTFields promoted a time-dependent increase in GEF-H1 phosphorylation with a peak after 10 minutes in cerebEND. Changes in claudin-5 phosphorylation paralleled GEF-H1 activation, however, the elevated levels of claudin-5 phosphorylation remained relatively stable during the treatment period investigated. Furthermore, ROCK activation in cerebEND was significantly increased after TTFields treatment. In addition, the distribution of claudin-5 in TTFields + fasudil-treated cells was similar to that in untreated control cells.

Conclusion: The use of TTFields in cerebEND leads to an effect on the GEF-H1/Rho/ROCK pathway similar to that previously demonstrated in cancer cells. Thus, these data indicate that ROCK is an essential component of signal transduction pathways that link TTFields-induced microtubule disruption with delocalization of claudin-5.