Direct current electrical fields induce apoptosis in oral mucosa cancer cells by NADPH oxidase-derived reactive oxygen species
Article first published online: 4 SEP 2007
Copyright © 2007 Wiley-Liss, Inc.
Volume 29, Issue 1, pages 47–54, January 2008
How to Cite
Wartenberg, M., Wirtz, N., Grob, A., Niedermeier, W., Hescheler, J., Peters, S. C. and Sauer, H. (2008), Direct current electrical fields induce apoptosis in oral mucosa cancer cells by NADPH oxidase-derived reactive oxygen species. Bioelectromagnetics, 29: 47–54. doi: 10.1002/bem.20361
- Issue published online: 14 DEC 2007
- Article first published online: 4 SEP 2007
- Manuscript Revised: 2 JUL 2007
- Manuscript Received: 4 DEC 2006
- reactive oxygen species;
- oral mucosa;
The presence of more than one dental alloy in the oral cavity often causes pathological galvanic currents and voltage resulting in superficial erosions of the oral mucosa and eventually in the emergence of oral cancer. In the present study the mechanisms of apoptosis of oral mucosa cancer cells in response to electromagnetic fields was investigated. Direct current (DC) electrical fields with field strengths between 2 and 16 V/m, applied for 24 h to UM-SCC-14-C oral mucosa cancer cells, dose-dependently resulted in decreased cell proliferation as evaluated by Ki-67 immunohistochemistry and upregulation of the cyclin-dependent kinase (CDK) inhibitors p21cip1/waf1 and p27kip1, which are associated with cell cycle arrest. Electrical field treatment (4 V/m, 24 h) increased apoptosis as evaluated by immunohistochemical analysis of cleaved caspase-3 and poly-(ADP-ribose)-polymerase-1 (PARP-1). Furthermore, robust reactive oxygen species (ROS) generation, increased expression of NADPH oxidase subunits as well as Hsp70 was observed. Electrical field treatment (4 V/m, 24 h) resulted in increased expression of Cu/Zn superoxide dismutase and decreased intracellular concentration of reduced glutathione (GSH), whereas the expression of catalase remained unchanged. Pre-treatment with the free radical scavenger N-acetyl cysteine (NAC) and the superoxide dismutase mimetic EUK-8 abolished caspase-3 and PARP-1 induction, suggesting that apoptosis in oral mucosa cancer cells is initated by ROS generation in response to DC electrical field treatment. Bioelectromagnetics 29:47–54, 2008. © 2007 Wiley-Liss, Inc.