Institute of Virology, Medical Center - University of Freiburg, Hermann-Herder Str. 11, D-79104, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Redox Biol. 2019 Sep;26:101301. doi: 10.1016/j.redox.2019.101301. Epub 2019 Aug 16.
Treatment of tumor cells with HO and nitrite, two long-lived species derived from cold atmospheric plasma, induces a complex autoamplificatory, singlet oxygen-mediated process, which leads to catalase inactivation and reactivation of intercellular apoptosis-inducing signaling. Experimental dissection and quantification of this process is described in this study. When tumor cells were pretreated with HO and nitrite, and then were added to untreated tumor cells, they propaged singlet oxygen mediated catalase inactivation and generation of singlet oxygen to the untreated cell population. This bystander effect allowed to analyze the biochemical requirements of a) induction of the bystander effect-inducing potential, b) transmission of the bystander effect to untreated neighbouring cells, and c) the biochemical consequences of these signaling events. The induction of bystander effect-inducing potential requires the generation of "primary singlet oxygen" through the reactions following the interaction between nitrite and HO, followed by local inactivation of a few catalase molecules. This primary effect seems to be very rare, but is efficiently enhanced by the generation of "secondary singlet oxygen" through the interaction between HO and peroxynitrite at the site of inactivated catalase. Transmission of bystander signaling between pretreated and untreated tumor cells depends on the generation of secondary singlet oxygen by the pretreated cells and singlet oxygen-mediated catalase inactivation of the untreated recipient cells. This induces autoamplificatory propagation of secondary singlet oxygen generation in the population. This experimental approach allowed to quantify the efficiencies of primary and secondary singlet oxgen generation after CAP and PAM action, to dissect the system and to study the underlying chemical biology in detail. Our data confirm that CAP and PAM-derived components are merely the trigger for the activation of autoamplificatory mechanisms of tumor cells, whereas the tumor cells efficiently propagate their cell death through their own ROS/RNS signaling potential.
用 HO 和亚硝酸盐处理肿瘤细胞,这两种都是来自冷大气压等离子体的长寿命物质,会诱导一种复杂的自动放大、单线态氧介导的过程,导致过氧化氢酶失活和细胞间凋亡诱导信号的再激活。本研究描述了这种过程的实验解析和定量。当肿瘤细胞用 HO 和亚硝酸盐预处理后,再加入未处理的肿瘤细胞,它们会传播单线态氧介导的过氧化氢酶失活,并向未处理的细胞群体产生单线态氧。这种旁观者效应允许分析以下生化要求:a)诱导旁观者效应诱导潜力,b)将旁观者效应传递给未处理的邻近细胞,以及 c)这些信号事件的生化后果。诱导旁观者效应诱导潜力需要通过亚硝酸盐和 HO 相互作用后的反应产生“初级单线态氧”,然后局部失活少数几个过氧化氢酶分子。这种初级效应似乎非常罕见,但通过 HO 和过氧亚硝酸盐在失活的过氧化氢酶部位相互作用产生“次级单线态氧”,可以有效地增强这种初级效应。预处理和未处理的肿瘤细胞之间旁观者信号的传递依赖于预处理细胞中次级单线态氧的产生以及未处理受体细胞中单线态氧介导的过氧化氢酶失活。这会诱导细胞群体中次级单线态氧生成的自动放大传播。这种实验方法允许定量 CAP 和 PAM 作用后初级和次级单线态氧生成的效率,解析系统,并详细研究潜在的化学生物学。我们的数据证实,CAP 和 PAM 衍生的成分只是肿瘤细胞自身 ROS/RNS 信号潜力激活自动放大机制的触发因素,而肿瘤细胞则有效地通过自身的 ROS/RNS 信号潜力传播其细胞死亡。