Antitumor effects of single and multiple electrochemotherapy on B16 melanoma

Electrochemotherapy (ECT) is a novel antitumor treatment which combines cytotoxic drug and strong electric fields. The essence of the ECT method is an increase of permeability of tumor cell plasma membrane under the influence of high voltage electric pulses. The electropores formed enable the weakly permeant drug molecules to diffuse through the plasma membrane more easily. This enables to potentiate the cytotoxic effect of the drug and thus to reduce the drug concentration in the blood. In this study the authors evaluated antitumor effectiveness of single and multiply ECT with bleompcin on B16 melanoma. The results of this study clearly show that the treatment combining cytotoxic drug bleomycin (BLM) and high voltage electric pulses is significantly more effective than the BLM alone. A significant improvement of antitumor effect was noticed when the combined treatment was repeated for second time. In these experimental groups some mice with 2-3 weeks complete responses were observed. It was also determined that the number and the interval of postgoing treatments could be important.