低频超声辐照微泡造影剂增强米托蒽醌对乳腺癌细胞的毒性作用

Enhancing cytotoxicity of Mitoxantrone on human breast cancer cell with microbubble contrast during low-frequency ultrasound exposure

目的观察超声辐照微泡造影剂对米托蒽醌杀伤人乳腺癌细胞MCF-7作用的影响,并探讨其作用机制。方法以MTT法检测米托蒽醌对MCF-7细胞的细胞毒作用,计算其24 h的IC50值。将对数生长期的人乳腺癌细胞MCF-7分为单纯米托蒽醌组(D组)、超声+米托蒽醌组(U+D组)、超声+微泡+米托蒽醌组(U+M+D组)、空白对照组(C组)。以MTT法检测各组细胞活性,高效液相色谱法测定用药各组细胞内米托蒽醌的含量,采用透射电镜观察MCF-7细胞形态学特征。结果米托蒽醌对MCF-7细胞的IC50值为2.87μg/ml。各组细胞经处理后培养24 h,细胞活性率C组>D组>U+D组>U+M+D组,各组间差异有统计学意义(P<0.05)。高效液相色谱法测定用药各组细胞内米托蒽醌的含量为U+M+D组>U+D组>D组,差异有统计学意义(P<0.05)。透射电镜可观察到MCF-7细胞凋亡的典型形态学改变。结论低频超声辐照可促进化疗药物进入肿瘤细胞内,增强化疗药物对肿瘤细胞的杀伤作用,而低频超声辐照微泡可进一步增强该效应。

Objective To investigate the antitumor effect and its mechanism of microbubble contrast combined with Mitoxantrone exposed to low-frequency ultrasound on human breast cancer cell MCF-7.Methods MTT method was applied to examine the growth inhibition of MCF-7 treated with Mitoxantrone.MCF-7 cells were randomly divided into 4 groups： Mitoxantrone group（group D）,ultrasound＋Mitoxantrone group（group U＋D）,ultrasound＋microbuble ＋Mitoxantrone group（group U＋M＋D） and control group（group C）.The cytoactive of each group was examined with MTT.The intracellular drug content in each group was measured with high performance liquid chromatography.The morphology of MCF-7 cells apoptosis was observed with transmission electron microscopy（TEM）.Results The IC 50 of Mitoxantrone was 2.87 μg/ml.The differences of cytoactive among all groups were significant（P 0.05）.The intracellular drug content of group U＋M＋D was higher than that of group U＋D,and the latter was higher than that of group D.The morphological changes of apoptosis were observed with TEM.Conclusion Low-frequency ultrasound can promote intracellular drug content as to enhance the sensitivity of chemotherapy drugs on tumor cells,and this effect can be enhanced by microbubble contrast exposure to low-frequency ultrasound.