Evidence for estrogenic contamination of the MAPK inhibitor PD98059.
Evidence for estrogenic contamination of the MAPK inhibitor PD98059.
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DOI：
10.1210/endo.142.12.8649
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发表时间：
2001-12
期刊：
影响因子：
4.8
通讯作者：
X. Long;E. A. Gize;K. Nephew;R. Bigsby
中科院分区：
文献类型：
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作者：
X. Long;E. A. Gize;K. Nephew;R. Bigsby
PD98059阻断MAPK蛋白、ERK1和ERK2的磷酸化和激活。在检测PD98059对人乳腺癌细胞系和酵母中雌激素诱导的报告基因转录的影响的过程中，我们发现四个不同批次的PD98059中有两个以剂量依赖的方式产生雌激素作用。在竞争性结合试验中，这些PD98059制剂取代了ER α中的放射性标记雌二醇。此外，在酵母实验中，添加辅助激活蛋白AIB1增强了PD98059的转录作用，表明它诱导了受体-辅助激活因子的相互作用。虽然在这些实验系统中激活ER α所需的PD98059浓度比雌二醇的浓度高10(4)到10(5)，但阻断MAPK激活所需的浓度远高于产生最大雌激素效应所需的浓度。因此，当PD98059用于雌激素应答细胞时，污染雌激素活性可能会混淆实验结果的解释。
PD98059 blocks phosphorylation and activation of MAPK proteins, ERK1 and ERK2. In the course of examining the effect of PD98059 on estrogen-induced transcription of reporter genes in a human breast cancer cell line and in yeast, we found that two of four different batches of PD98059 produced estrogenic effects in a dose-dependent manner. In a competitive binding assay, these preparations of PD98059 displaced radiolabeled estradiol from ER alpha. Furthermore, in the yeast assay, addition of a coactivator protein, AIB1, enhanced the transcriptional effect of PD98059, indicating that it induces receptor-coactivator interactions. Although concentrations of PD98059 required to activate ER alpha in these experimental systems are 10(4)- to 10(5) higher than the concentration of estradiol required to do the same, the concentrations required to block MAPK activation are well above those which would produce maximal estrogenic effects. Thus, when PD98059 is used in estrogen-responsive cells, contaminating estrogenic activity may confound interpretation of experimental results.