Hypoxic inducible factor 1α, extracellular signal-regulated kinase, and p53 are regulated by distinct threshold concentrations of nitric oxide
Hypoxic inducible factor 1α, extracellular signal-regulated kinase, and p53 are regulated by distinct threshold concentrations of nitric oxide
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DOI：
10.1073/pnas.0400453101
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发表时间：
2004-06-15
影响因子：
11.1
通讯作者：
Wink, DA
中科院分区：
文献类型：
--
作者：
Thomas, DD;Espey, MG;Wink, DA
肿瘤中产生的NO可以正向或负向调节生长。为了研究这种二分法，在有氧条件下，在人乳腺MCF 7细胞中研究了NO浓度和持续时间对几种关键蛋白的翻译后调节的影响。我们发现，不同的浓度阈值的NO似乎引起一组离散的信号转导途径。在低稳态浓度的NO（100 nM），而p53丝氨酸15磷酸化发生在相当高的水平（>300 nM）。ERK磷酸化在NO暴露期间是短暂的。HIF-1 α的稳定化抑制了NO的存在，而p53丝氨酸15磷酸化在NO暴露期间被检测到，并且在NO暴露后持续存在。合成的NO供体的剂量依赖性效应通过与MCF 7细胞以不同比例共培养的活化的巨噬细胞来模仿。ERK和HIF-1 α的激活在乳腺癌细胞系中是相似的，无论是p53的突变体（MB 231）还是无效（MB 157）。随着MCF 7细胞密度的增加，没有观察到NO对HIF-1 α的稳定作用，这表明NO和O-2消耗之间存在相互关系。研究结果表明，NO暴露的浓度和持续时间是调节肿瘤相关蛋白的关键决定因素。
NO produced in tumors can either positively or negatively regulate growth. To examine this dichotomy, effects of NO concentration and duration on the posttranslational regulation of several key proteins were examined in human breast MCF7 cells under aerobic conditions. We found that different concentration thresholds of NO appear to elicit a discrete set of signal transduction pathways. At low steady-state concentrations of NO (100 nM), whereas p53 serine 15 phosphorylation occurred at considerably higher levels (>300 nM). ERK phosphorylation was transient during NO exposure. HIF-1alpha stabilization paralleled the presence of NO, whereas p53 serine 15 phosphorylation was detected during, and persisted after, NO exposure. The dose-dependent effects of synthetic NO donors were mimicked by activated macrophages cocultured with MCF7 cells at varying ratios. ERK and HIF-1alpha activation was similar in breast cancer cell lines either mutant (MB231) or null (MB157) in p53. The stabilization of HIF-1alpha by NO was not observed with increased MCF7 cell density, demonstrating the interrelationship between NO and O-2 consumption. The findings show that concentration and duration of NO exposure are critical determinants in the regulation of tumor-related proteins.