吡罗昔康声动力效应对乳腺癌细胞生物学作用及其机制的实验研究

The bioeffect of sonodynamic therapy with piroxicam on human breast cancer cells and its potential mechanism

目的 探讨吡罗昔康介导的声动力效应对乳腺癌细胞的急性细胞毒作用及其作用机制。方法 采用噻唑蓝（MTT）比色法检测吡罗昔康声动力效应对乳腺癌细胞的急性杀伤作用和活性氧清除剂对声动力作用的影响，用透射电镜观察细胞超微结构，用吖啶橙／溴化乙啶（AO／EB）双染法和流式细胞仪（FCM）检测细胞凋亡、线粒体跨膜电位（MMP）及活性氧（ROS）水平。结果 单纯应用超声有杀伤细胞和诱导细胞凋亡的作用，而吡罗昔康存在时，这一作用更为显著，声动力组细胞凋亡率和ROS水平亦明显高于单纯超声组，而MMP却显著低于后者。且组氨酸能够显著抑制吡罗昔康声动力效应，而甘露醇对其无明显影响。结论吡罗昔康介导的声动力作用对乳腺癌细胞具有显著的杀伤效应和诱导凋亡作用，这可能与声动力作用后MDA—M昏231细胞内ROS增加所致MMP下降有关。

Objective To observe the acute cytotoxic effect and apoptosis of sonodynamic therapy （SDT） with piroxicam on human mammary cancer cell line MDA-MB-231 and explore its potential mechanism. Methods The acute cytotoxic effect of SDT with or without piroxicam and effect of active oxygen scavengers on SDT after insonation on MDA-MB-231 cells was evaluated by MTT colormetric assay, the morphological changes of MDA-MB-231 cells were observed using transmission electron microscope. Furtherly, flow cytometry（FCM） was applied to analyze the apoptosis rate, mitochondrial membrane potential（MMP） and reactive oxygen species（ROS） in MDA-MB-231 cells. Results A marked cell-killing effect and apoptotic rates of SDT with piroxicam on MDA-MB-231 cells was observed,but MMP in MDA-MB-231 cells obviously dropped after SDT with piroxicam. Histidine could significantly inhibit the cell-killing effect of SDT with piroxicam,but mannitol could not significantly reduce it. Conclusions SDT with piroxicam could kill MDA-MB-231 cells and induce them apoptosis them. As to the mechanism of SDT, some ROS such as singlet oxygen,which was produced under ultrasonic irradiation in the presence of piroxicam, might decrease MMP and so induce MDA-MB-231 cells apoptosis.