Nanosecond pulsed electric fields cause melanomas to self-destruct

Nanosecond pulsed electric fields (nsPEF) have been shown to penetrate into living cells to permeabilize intracellular organelles and release Ca2+ from the endoplasmic reticulum. They provide a new approach for physically targeting intracellular organelles with many applications, including initiation of apoptosis, enhancement of gene transfection efficiency and inhibiting tumor growth. We have been working with the murine melanoma model system and here we show that 40 kV/cm electric field pulses 300 nanoseconds in duration can rapidly stimulate pyknosis, reduce blood flow and fragment DNA in murine melanoma tumors in vivo with a total field exposure time of 1.8 microseconds. Three treatments of 100 pulses each results in a mean tumor size regression of 90% within two weeks. Another round of treatments at this time can completely eliminate the melanoma. This new therapy is the first to simultaneously trigger pyknosis and reduce tumor blood flow.