Non-thermal atmospheric plasma induces ROS-independent cell death in U373MG glioma cells and augments the cytotoxicity of temozolomide.
Non-thermal atmospheric plasma induces ROS-independent cell death in U373MG glioma cells and augments the cytotoxicity of temozolomide.
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DOI：
10.1038/bjc.2016.12
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发表时间：
2016-02-16
影响因子：
8.8
通讯作者：
Curtin JF
中科院分区：
文献类型：
--
作者：
Conway GE;Casey A;Milosavljevic V;Liu Y;Howe O;Cullen PJ;Curtin JF
非热大气等离子体（NTAP）是一种在高压下产生的电离气体，可以产生短命的化学活性物质并诱导癌细胞产生细胞毒性损伤。文献中已经报道了对 NTAP 介导的细胞毒性的细胞特异性抗性。本研究的目的是确定是否可以使用人神经胶质瘤细胞系 U373MG 克服对 NTAP 的耐药性。非热大气等离子体是使用介质阻挡装置（DBD）系统产生的，在50Hz时最大电压输出为120kV。使用形态学、流式细胞术和细胞毒性测定法测定 U373MG GBM 细胞和 HeLa 宫颈癌细胞的活力。荧光探针和抑制剂用于确定暴露于等离子体场的细胞的细胞毒性机制。探索了替莫唑胺 (TMZ) 联合治疗和多剂量治疗作为克服 NTAP 耐药性的机制。非热大气等离子体以剂量（时间）依赖性方式降低细胞活力。与 HeLa 细胞相比，U373MG 细胞对 NTAP 处理具有抵抗力，并且暴露于等离子体场后，U373MG 细胞中定量的细胞内活性氧 (ROS) 水平远低于 HeLa 细胞。活性氧抑制剂 N-乙酰半胱氨酸 (NAC) 仅减轻 HeLa 细胞中的细胞毒性作用，而不能减轻相对 NTAP 耐药的细胞系 U373MG 中的细胞毒性作用。 U373MG 中较长时间暴露于 NTAP 会诱导细胞死亡，与 ROS、JNK 和半胱天冬酶无关。当与低浓度 GBM 化疗药物 TMZ 联合使用或暴露于多次剂量时，可以克服 U373MG 细胞对 NTAP 的相对耐药性。我们首次报道 NTAP 在 U373MG GBM 细胞系中诱导 ROS、JNK 和 caspase 独立的细胞死亡机制，当与低剂量 TMZ 联合使用时，该机制可以大大增强。当与新的和现有的化疗方案结合使用时，该技术的进一步完善可能有助于针对 GBM 的细胞毒性的局部激活。
Non-thermal atmospheric plasma (NTAP) is an ionised gas produced under high voltage that can generate short-lived chemically active species and induce a cytotoxic insult in cancer cells. Cell-specific resistance to NTAP-mediated cytotoxicity has been reported in the literature. The aim of this study was to determine whether resistance against NTAP could be overcome using the human glioma cell line U373MG. Non-thermal atmospheric plasma was generated using a Dielectric Barrier Device (DBD) system with a maximum voltage output of 120 kV at 50 Hz. The viability of U373MG GBM cells and HeLa cervical carcinoma cells was determined using morphology, flow cytometry and cytotoxicity assays. Fluorescent probes and inhibitors were used to determine the mechanisms of cytotoxicity of cells exposed to the plasma field. Combinational therapy with temozolomide (TMZ) and multi-dose treatments were explored as mechanisms to overcome resistance to NTAP. Non-thermal atmospheric plasma decreased cell viability in a dose (time)-dependent manner. U373MG cells were shown to be resistant to NTAP treatment when compared with HeLa cells, and the levels of intracellular reactive oxygen species (ROS) quantified in U373MG cells were much lower than in HeLa cells following exposure to the plasma field. Reactive oxygen species inhibitor N-acetyl cysteine (NAC) only alleviated the cytotoxic effects in HeLa cells and not in the relatively NTAP-resistant cell line U373MG. Longer exposures to NTAP induced a cell death independent of ROS, JNK and caspases in U373MG. The relative resistance of U373MG cells to NTAP could be overcome when used in combination with low concentrations of the GBM chemotherapy TMZ or exposure to multiple doses. For the very first time, we report that NTAP induces an ROS-, JNK- and caspase-independent mechanism of cell death in the U373MG GBM cell line that can be greatly enhanced when used in combination with low doses of TMZ. Further refinement of the technology may facilitate localised activation of cytotoxicity against GBM when used in combination with new and existing chemotherapeutic regimens.