ABSTRACT
Objective Study on the intracellular calcium and growth suppression of human breast cancer cells exposed by high intensity ultrasound (HIU). Methods Exposed human breast cancer cells MDA-MB-231 and MCF-7 in vitro with HIU (50 W/cm2). Examined the intracellular calcium from exposed cells with Fura-2 fluorescence probe. The cell viabilities were measured by MTT assay. The rate of cell apoptosis and distribution of cell cycle were detected on flow cytometry. Results The lever of intracellular calcium went up in pace with exposed time of HIU, MCF-7 cells were (572±20.1), (670±18.9), (815± 16.3) nmol/L (F = 663.65, P＜0.001), MDA-MB-231 cell was (582±16.3), (687±19.7), (843± 14.8) nmol/L (F = 863.06, P＜0.001), and the distribution of cell cycle waved to G0-G1, the ratios of G0-G1 in MCF-7 and MDA-MB-231 were (60.5±5.5)%, (66.3±7.0)%, (74.5±8.2)% (F=8.17, P = 0.002) and (58.5± 6.3) %, (66.1±6.3)%, (71.2±7.9) % (F=7.51, F= 0.003). Apoptotic rate upgraded gradually, the apoptotic rates of MCF-7 and MDA-MB-231 were (7.3±1.7)%, (13.2±3.5) %, (19.3±3.7)% (F= 18.73, P＜0.001) and (6.3±1.8)%, (11.4±2.31)%, (16.4±3.3)% (F = 19.26, P＜0.001). Under MTT assay, the rate of cell growth suppression increased significantly, the rates of cell growth suppression in MCF-7 and MDA-MB-231 were (9.2±2.2) %, (24.3±3.9)%, (48.6±5.5)%(F=117.16, P ＜0.001) and (9.0±1.7)%, (22.3±3.5) %, (416± 6.4)% (F =71.25, P＜0.001). Conclusion HIU enhanced the intracellular calcium of human breast cancer cells within given time and promoted the distribution of cell cycle to G0-G1. The rate of cell apoptosis and the cell's death rate increased evidently.