Induction of apoptosis in human leukemic cells by ultrasonic low energy treatment

Abstract

Abstract The biophysical effects of ultrasound have been frequently surveyed and its use has been proposed for some years, often in conjunction with other energy types (hyperthermia, radiation) for the treatment of cancer cells. This procedure requires long preparation, energy and the use of photosensitizers. In contrast, the technique described here, using diagnostic ultrasonic frequencies, requires a low acoustic power level and, in the absence of any chemical synergy, triggers apoptosis in leukemic cells. 2 hours after ultrasonic treatment of K562 cells, a sequence of events recognized as hallmarks of apoptosis was observed: depletion of glutathione, a drop of mitochondrial potential, translocation of phospatidylserine and, subsequently, loss of membrane integrity. These effects are not dependent on the formation of species issued from the sonolysis of the solvent medium. By using minute amounts of energy, necrosis generally associated with a high physiological stress is minimized (