高强度聚焦超声对人乳腺癌细胞的生长抑制作用及机理研究

A Study of the Inhibition Effect of HIFU and Its Mechanism of Action on the Proliferation of Human Breast Cancer Cells

目的 研究高强度聚焦超声 (HIFU)对人肿瘤细胞的杀伤作用 ,并探索其作用机理。方法 用不同强度HIFU处理人乳腺癌细胞 MCF- 7,用台盼蓝排斥法染色、细胞增殖试验 (MTT法 )、克隆形成实验研究 HIFU对癌细胞的杀伤和生长抑制作用 ;用流式细胞术检测 HIFU对癌细胞周期、凋亡及相关基因表达的影响。结果 用 HIFU处理后 ,癌细胞死亡率升高 ,增殖活性降低 (P<0 .0 5 ) ,克隆形成下降 (P<0 .0 0 1) ,G0 /G1 期细胞数增加 (P<0 .0 5 ) ,S期细胞数减少 (P<0 .0 1) ,凋亡指数升高 (P<0 .0 1) ,热休克蛋白表达升高 (P<0 .0 5 ) ,P5 3、BCL- 2、FAS表达阳性细胞数与对照组比 ,无显著性差异 (P>0 .0 5 )。结论 HIFU对人乳腺癌细胞有明显的杀伤及抑制生长和克隆形成作用 ,其机理与抑制 DNA合成有关 ;HIFU具有诱导癌细胞凋亡作用 ,可能与 P5 3、BCL- 2、FAS的介导和调控无关。

Objective To investigate the killing effect of high intensity focused ultrasound(HIFU)on human tumor cells and study the mechanism of its action. Methods Human breast cancer cells MCF-7 were treated with different intensity of HIFU in vitro and incubated. The killing effect and proliferation inhibition effect of HIFU on tumor cells were investigated with the methods of trypan blue exclusion assay, MTT assay and colony formation assay. And the cell cycle, apoptotic cells and the expressions of P53,BCL-2,FAS and HSP70 were measured with flow cytometry. Results After HIFU treatment, the death rates of cancer cell increased, the proliferation of cell waned (P<0.05), the number of colony formation decreased (P<0.001), the cell number increased in G 0/G 1 phase (P<0.05) and decreased in S phase, the apoptotic indices increased (P<0.01), the expression of HSP70 was enhanced, and no significant changes of P53, BCL-2, FAS expressions were found (P>0.05). Conclusion HIFU produces significant effects such as killing, proliferation inhibition and colony formation inhibition on human breast cancer cells; its mechanism of action may be associated with the inhibition of DNA synthesis. In addition, HIFU treatment can induce apoptotic cell death, which may not be associated with the mediation and regulation of P53, BCL-2 and FAS genes.