A Study of the Intracellular Routing of Cytotoxic Ribonucleases (*)
A Study of the Intracellular Routing of Cytotoxic Ribonucleases (*)
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DOI：
10.1074/jbc.270.29.17476
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发表时间：
1995-07
期刊：
影响因子：
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通讯作者：
You-Neng Wu;S. Saxena;W. Ardelt;M. Gadina;S. Mikulski;C. De Lorenzo;G. D'alessio;R. Youle
中科院分区：
文献类型：
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作者：
You-Neng Wu;S. Saxena;W. Ardelt;M. Gadina;S. Mikulski;C. De Lorenzo;G. D'alessio;R. Youle
几种核糖核酸酶在宿主防御和生理细胞死亡途径中充当细胞毒性剂。虽然胰腺核糖核酸酶A超家族的某些成员在应用于细胞外部时可能是有毒的，但当人工引入细胞溶质时，它们的毒性会增加数千倍，这表明内化是细胞毒性的限速步骤。我们已经使用了三种不同的机制，视黄酸，布雷菲德菌素A，和莫能菌素，破坏高尔基体，以探测核糖核酸酶的细胞内途径到达胞质溶胶。视黄酸和莫能菌素增强牛精液RNA酶、Onconase、血管生成素和人核糖核酸酶A的细胞毒性100倍或更多。布雷菲德菌素A完全阻断视黄酸介导的核糖核酸酶增强作用。核糖核酸酶似乎更有效地通过高尔基体破坏莫能菌素或视黄酸的路由到胞质溶胶。在视黄酸存在下，BS-RNase的细胞内RNA降解增加超过100倍，证实RNase到达细胞溶质，并表明RNA降解是引起毒性的细胞内损伤。由于单独的视黄酸和Onconase处于癌症治疗的临床试验中，RNA酶和视黄酸的体内组合可以提供新的临床用途。
Several ribonucleases serve as cytotoxic agents in host defense and in physiological cell death pathways. Although certain members of the pancreatic ribonuclease A superfamily can be toxic when applied to the outside of cells, they become thousands of times more toxic when artificially introduced into the cytosol, indicating that internalization is the rate-limiting step for cytotoxicity. We have used three agents that disrupt the Golgi apparatus by distinct mechanisms, retinoic acid, brefeldin A, and monensin, to probe the intracellular pathways ribonucleases take to reach the cytosol. Retinoic acid and monensin potentiate the cytotoxicity of bovine seminal RNase, Onconase, angiogenin, and human ribonuclease A 100 times or more. Retinoic acid-mediated potentiation of ribonucleases is completely blocked by brefeldin A. Ribonucleases appear to route more efficiently into the cytosol through the Golgi apparatus disrupted by monensin or retinoic acid. Intracellular RNA degradation by BS-RNase increased more than 100 times in the presence of retinoic acid confirming that the RNase reaches the cytosol and indicating that degradation of RNA is the intracellular lesion causing toxicity. As retinoic acid alone and Onconase are in clinical trials for cancer therapy, combinations of RNases and retinoic acid in vivo may offer new clinical utility.