Abstract
To investigate the effects of low-intensity ultrasound on human malignant melanoma (C-32), cells in vitro and C-32 tumor in mice were exposed to 0.1-0.5 W/cm^2 (1.011-MHz) ultrasound. In another experiments, cells in vitro and in vivo were sonotransfected with the following genes: GFP, IFN-beta, and GFP tagged IFN-beta gene, after micro-bubbles were added. Two minutes daily sonication resulted in growth inhibition. Neither significant cell killing nor change in cell migration activity was observed, but several genes were either up- or down-regulated. Sonotransfection with IFN-beta resulted in cell killing, apoptosis induction and overall growth inhibition of melanoma. While GFP sonotransfection did not significantly affect cell growth, it was shown that cells transfected with GFP-tagged IFN-beta genes were more likely to undergo apoptosis. In addition, growth of cells sub-cultured with sonotransfected cells was also inhibited. These findings suggest the potential use of low-intensity ultrasound against malignant melanoma.
