OBJECTIVES The aim of the present study is to investigate the effects of sonodynamic action of hypocrellin B on human breast cancer cells and further explore its underlying mechanisms. METHODS The cell viability of breast cancer MDA‐MB‐231 cells was examined by 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyl tetrazolium bromide (MTT) assay. Alterations on cell apoptosis, intracellular reactive oxygen species generation (ROS), mitochondrial membrane potential, and DNA fragmentation was analyzed by flow cytometer. The subcellular localization of hypocrellin B was assessed by a confocal laser scanning microscope. Mitochondria damage and nuclear morphological changes were observed under a fluorescence microscope. To further explore whether caspase pathway was involved in cell apoptotic induction of sonodynamic action of hypocrellin B, the pan‐caspase inhibitor Z‐Val‐Ala‐DL‐Asp (ome)‐Fluoromethylketone (z‐VAD‐fmk) was added to the cells one hour prior to loading the sonosensitizer, and then cell viability and apoptosis were analyzed after hypocrellin B treatment. RESULTS Sonodynamic treatment of hypocrellin B HB significantly suppressed cell viability of MDA‐MB‐231 cells. Sonodynamic action of hypocrellin B caused excessive ROS accumulation, mitochondrial dysfunction, cell apoptosis, DNA fragmentation and nuclear morphological damage. Moreover, the cytotoxicity and cell apoptosis induced by sonodynamic action of hypocrellin B were remarkably rescued by the caspase spectrum inhibitor z‐VAD‐fmk. CONCLUSIONS These results demonstrated that hypocrellin B had significant sonodynamic killing and apoptotic induction effect on breast cancer cells. And cell apoptosis induced by sonodynamic action of hypocrellin B was partly dependent on caspase pathway. HIGHLIGHTSHB‐SDT suppressed cell viability, potentiated ROS generation in MDA‐MB‐231 cells.HB‐SDT damaged the structure and function of mitochondria.The apoptotic response was triggered after HB‐SDT treatment.Caspase pathway was involved in the mechanisms of cell death induced by HB‐SDT.

中文翻译：

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Hypocrellin B 的声动力学作用触发涉及 caspase 途径的乳腺癌细胞的细胞凋亡

目的本研究的目的是研究hypocrellin B对人乳腺癌细胞的声动力学作用的影响，并进一步探讨其潜在机制。方法 采用 3-(4, 5-二甲基噻唑-2-基)-2, 5-二苯基溴化四唑 (MTT) 法检测乳腺癌 MDA-MB-231 细胞的细胞活力。通过流式细胞仪分析细胞凋亡、细胞内活性氧生成 (ROS)、线粒体膜电位和 DNA 碎片的变化。通过共聚焦激光扫描显微镜评估hypocrellin B 的亚细胞定位。在荧光显微镜下观察线粒体损伤和核形态变化。为了进一步探讨半胱天冬酶途径是否参与了hypocrellin B的声动力学作用的细胞凋亡诱导，在加载声敏剂前一小时将泛半胱天冬酶抑制剂 Z-Val-Ala-DL-Asp (ome)-氟甲基酮 (z-VAD-fmk) 添加到细胞中，然后在下丘脑 B 后分析细胞活力和细胞凋亡治疗。结果：hypocrellin B HB 的声动力学处理显着抑制了 MDA-MB-231 细胞的细胞活力。hypocrellin B 的声动力学作用导致过量的 ROS 积累、线粒体功能障碍、细胞凋亡、DNA 断裂和核形态损伤。此外，半胱天冬酶谱抑制剂z-VAD-fmk显着挽救了由hypocrellin B的声动力学作用诱导的细胞毒性和细胞凋亡。结论这些结果表明hypocrellin B对乳腺癌细胞具有显着的声动力学杀伤和凋亡诱导作用。由hypocrellin B的声动力学作用诱导的细胞凋亡部分依赖于caspase途径。HIGHLIGHTSHB-SDT 抑制细胞活力，增强 MDA-MB-231 细胞中 ROS 的产生。HB-SDT 破坏线粒体的结构和功能。在 HB-SDT 治疗后触发细胞凋亡反应。Caspase 通路参与细胞死亡的机制HB-SDT 诱导。