Mechanism of Photofrin-enhanced Ultrasound-induced Human Glioma Cell Death

Background: Low-intensity ultrasound showed tumor cell killing by a non-thermal effect in human leukemia cells. The aim of our study was to investigate the efficacy of low-intensity ultrasound on malignant astrocytic tumor cells with the photosensitizer, Photofrin, which is taken up by the cell surface receptor, low density lipoprotein receptor-related protein/α2-macroglobulin receptor (LRP/α2MR). Materials and Methods: Cells were sonicated with continuous wave ultrasound with or without the presence of Photofrin (75 mg/ml) at an intensity of 0.3 W/cm 2 for a duration of 5, 15, or 30 s. Results: Ultrasound alone induced instant cell killing immediately after sonication in both U251MG and U105MG malignant