Induction of Apoptosis and Necrosis in Cancer Cells by Electric Fields, Electromagnetic Fields, and Photodynamically Active Quinoids

Abstract

Bioelectrochemical and electromagnetic methods are widely known to modify or even inhibit biochemical processes. In this respect apoptosis induction and necrosis of cancer cells (e.g. K-562, U-973 or HL-60) are of considerable interest as an adjuvant therapy. The synergistic combination with photodynamic activity is a novel possibility to enhance the efficacy of electromagnetic methods, as shown for quinoid drugs reacting as photodynamic Type 1 radicals. Some of these light reactions were applied to electroporated cancer cells producing the highest percentage of necrosis for cells in suspension. In order to avoid metallic electrodes for such single pulse application a non-invasive treatment it was demonstrated that using pulsating electromagnetic fields (50 Hz) one is able to cause necrosis itself. Moreover this effect is strengthened in the presence of quinoid anthracyclines and actinomycin-C. Additional exposure using visible light yields a maximum lethality. Hence this non-invasive treatment will be of advantage for future development as an adjuvant therapy.

Key Words:

• Cancer cells
• Necrosis
• Synergism
• electroporation + photodynamic effect
• Pulsating Electromagnetic Field (PEMF)