Glutathione depletion greatly reduces neocarzinostatin cytotoxicity in Chinese hamster V79 cells.
Glutathione depletion greatly reduces neocarzinostatin cytotoxicity in Chinese hamster V79 cells.
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谷胱甘肽消耗大大降低了新制癌菌素对中国仓鼠 V79 细胞的细胞毒性。
DOI：
10.1016/s0021-9258(17)39472-3
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
J. Mitchell
中科院分区：
文献类型：
--
作者：
W. Degraff;A. Russo;J. Mitchell
在中国仓鼠 V79 细胞中研究了细胞内硫醇谷胱甘肽在新制癌菌素还原激活中的作用。用降低（丁硫氨酸亚磺酰亚胺或马来酸二乙酯）或升高（氧代噻唑烷羧酸盐）细胞内谷胱甘肽水平的试剂预处理细胞。然后将这些细胞暴露于1-5微克/ml新制癌菌素1小时并测定存活率。将谷胱甘肽消耗至检测限或低于检测限的水平会导致新制癌菌素细胞毒性显着降低，而将谷胱甘肽水平增加至对照值的 250% 对新制癌菌素毒性几乎没有影响或没有影响。对未经处理和谷胱甘肽耗尽的细胞中的半胱氨酸进行高效液相色谱分析，结果显示半胱氨酸水平低于 0.2 µM，表明半胱氨酸在未处理或谷胱甘肽耗尽的细胞中新制癌菌素的还原激活中不起主要作用。当通过氧化噻唑烷羧酸盐处理谷胱甘肽耗尽的细胞来人为提高细胞内半胱氨酸水平时，新制癌菌素的毒性约为谷胱甘肽水平正常细胞中的三分之二。在无细胞系统中，其他人已经证明，2-巯基乙醇等还原剂对于将新制癌菌素活化为可切割 DNA 的物质是必需的。在这项研究中，我们确定谷胱甘肽是在哺乳动物细胞系中激活新制癌菌素的主要细胞还原剂。
The role of the intracellular thiol glutathione in the reductive activation of neocarzinostatin was investigated in Chinese hamster V79 cells. The cells were pretreated with agents that either lower (buthionine sulfoximine or diethyl maleate) or elevate (oxothiazolidine carboxylate) intracellular glutathione levels. These cells were then exposed to 1-5 micrograms/ml neocarzinostatin for 1 h and assayed for survival. Depletion of glutathione to levels at or below the limit of detection resulted in a marked reduction in neocarzinostatin cytotoxicity, while increasing glutathione levels to 250% of control values had little or no effect on neocarzinostatin toxicity. High performance liquid chromatography analysis of cysteine in untreated and glutathione-depleted cells showed cysteine levels lower than 0.2 microM, indicating that cysteine does not play a major role in the reductive activation of neocarzinostatin in untreated or glutathione-depleted cells. When intracellular cysteine levels were artificially elevated by oxothiazolidine carboxylate treatment of glutathione-depleted cells, neocarzinostatin toxicity was about two-thirds that seen in cells with normal glutathione levels. In cell-free systems, others have shown that reducing agents such as 2-mercaptoethanol are necessary for the activation of neocarzinostatin to a species that will cleave DNA. In this study, we have identified glutathione as the major cellular reducing agent for the activation of neocarzinostatin in a mammalian cell line.