Potentiation of cytotoxicity of adriamycin on human ovarian carcinoma cellline 3AO by low-level ultrasound

The aim of this study was to determine whether the ultrasound, with a dosag e that did not lead to acute and delayed inhibition, could potentiate the c ytotoxicity of adriamycin to human ovarian carcinoma cell line 3AO in vitro . Drug sensitivity was analyzed by clonogenic assay, cells were treated by adriamycin singly in group ADM (control), adriamycin prior to ultrasound ex posure in group ADM + US, and ultrasound irradiation prior to adriamycin ad ministration in group US + ADM. The intracellular drug accumulation in each group was determined by fluorometry. The results were: (1) the values of I C50 were 0.0083, <0.001 and 0.0065 mug/ mi in group ADM, ADM + US and US ADM respectively; the clone surviving rate in group ADM + US and in group U S + ADM were decreased (P < 0.001, P < 0.01), compared with control; the su rviving rate in group ADM + US was lower than that in group US + ADM (P < 0 .01). (2) The intracellular drug accumulations in group ADM + US were promo ted (P < 0.01) and not increased significantly in group US + ADM (P > 0.05) . These suggested that the low-level ultrasound could enhance the cytotoxic ity of adriamycin to human ovarian carcinoma cells and promoted intracellul ar drug contents played the leading role. (C) 2001 Elsevier Science B.V. Al l rights reserved.