Effect of platinum nanoparticles on cell death induced by ultrasound in human lymphoma U937 cells
Effect of platinum nanoparticles on cell death induced by ultrasound in human lymphoma U937 cells
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DOI：
10.1016/j.ultsonch.2015.12.013
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发表时间：
2016-07-01
影响因子：
8.4
通讯作者：
Kondo, Takashi
中科院分区：
文献类型：
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作者：
Jawaid, Paras;Rehman, Mati Ur;Kondo, Takashi
在这项研究中，我们报告了铂纳米颗粒（Pt-NPs），超氧化物歧化酶（SOD）/过氧化氢酶模拟抗氧化剂，与1 MHz超声（US）结合使用的潜在用途，超声强度为0.4 W/cm（2），占空比为10%，100 Hz PRF，持续2 min。通过DNA片段化试验，细胞周期分析和Annexin V-FITC/PI染色评估凋亡诱导。通过细胞计数和显微镜检查确认细胞杀伤。线粒体和Ca 2+依赖的途径进行了研究。分光光度法检测Caspase-8的表达，Western blot检测自噬相关蛋白的表达。细胞内活性氧（ROS）的升高通过流式细胞术检测，而细胞外自由基的形成通过电子顺磁共振自旋捕获光谱法进行评估。结果表明，Pt-NPs发挥不同的影响，这取决于他们的内化。当在超声处理之前立即加入时，Pt-NPs充当有效的自由基清除剂，而用Pt-NPs预处理抑制了细胞凋亡和自噬（AP）的诱导，并导致增强的细胞杀伤。死亡细胞具有固缩特征。细胞死亡的确切模式仍不清楚。总之，结果表明，超声诱导的AP可能有助于超声处理后的细胞存活。据我们所知，这是第一项讨论自噬作为US背景下的促生存途径的研究。Pt-NPs联合US可能是有效的癌症根除方法。(C)© 2016 Elsevier B. V.版权所有。
In this study, we report on the potential use of platinum nanoparticles (Pt-NPs), a superoxide dismutase (SOD)/catalase mimetic antioxidant, in combination with 1 MHz ultrasound (US) at an intensity of 0.4 W/cm(2), 10% duty factor, 100 Hz PRF, for 2 min. Apoptosis induction was assessed by DNA fragmentation assay, cell cycle analysis and Annexin V-FITC/PI staining. Cell killing was confirmed by cell counting and microscopic examination. The mitochondrial and Ca2+-dependent pathways were investigated. Caspase-8 expression and autophagy-related proteins were detected by spectrophotometry and western blot analysis, respectively. Intracellular reactive oxygen species (ROS) elevation was detected by flow cytometry, while extracellular free radical formation was assessed by electron paramagnetic resonance spin trapping spectrometry. The results showed that Pt-NPs exerted differential effects depending on their internalization. Pt-NPs functioned as potent free radical scavengers when added immediately before sonication while pre-treatment with Pt-NPs suppressed the induction of apoptosis as well as autophagy (AP), and resulted in enhanced cell killing. Dead cells displayed the features of pyknosis. The exact mode of cell death is still unclear. In conclusion, the results indicate that US-induced AP may contribute to cell survival post sonication. To our knowledge this is the first study to discuss autophagy as a pro-survival pathway in the context of US. The combination of Pt-NPs and US might be effective in cancer eradication. (C) 2016 Elsevier B.V. All rights reserved.