RESUMEN
Objective To study the mechanism of high intensity ultrasound (HIU) on COX-2 mRNA expression and apoptosis in breast cancer cell line MDA-MB-231 cells.Methods Human breast cancer cells MDA-MB-231 in vitro were exposed in HIU (50 w/cm2).RT-PCR was performed to detect the level of COX-2 mRNA before and after exposure.The ultrastructural changes in apoptotic cells were examined by transmission electron microscopy.Results The relative level of COX-2 mRNA decreased gradually along with the increase of exposure time and apoptotic bodies in MDA-MB-231 cells considerably increased under electron microscope.When exposure time was increased to 30 seconds,a few cells died.Conclusion HIU promotes apoptosis of breast cancer MDA-MB-231 cells in a COX-2 mRNA depended way.