Figure 1.

In vitro comparison of the sensitivity to chemotherapy and electrochemotherapy and electropermeability between the parental cell line and radioresistant subline. Survival curves of radiosensitive (FaDu) and radioresistant (FaDu-RR) cells after (A) 2-h exposure to cisplatin or (B) bleomycin and after electrochemotherapy with (C) cisplatin or (D) bleomycin. (E and F) Electropermeabilization of the cell membranes after exposure to electric pulses. The data for the electrochemotherapy are normalized to the corresponding control group without the chemotherapeutic agent (with or without pulse application). CDDP, cisplatin; BLM, bleomycin; ECT, electrochemotherapy; PI, propidium iodide. *P<0.001. Data are represented as arithmetic mean (AM) and standard error of the mean (SEM) (AM ± SEM) of at least 3 independent experiments performed in triplicates. Dashed lines represent inhibitory concentration of the chemotherapeutic killing 50% of the cells (IC₅₀). Dotted lines in E and F represent electric field intensity of 1,300 V/cm.