Superinduction of CYP1A1 in MCF10A cultures by cycloheximide, anisomycin, and puromycin:: A process independent of effects on protein translation and unrelated to suppression of aryl hydrocarbon receptor proteolysis by the proteasome
Superinduction of CYP1A1 in MCF10A cultures by cycloheximide, anisomycin, and puromycin:: A process independent of effects on protein translation and unrelated to suppression of aryl hydrocarbon receptor proteolysis by the proteasome
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DOI：
10.1124/mol.66.4.936
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发表时间：
2004-10-01
影响因子：
3.6
通讯作者：
Reiners, JJ
中科院分区：
文献类型：
--
作者：
Joiakim, A;Mathieu, PA;Reiners, JJ
暴露于大于或等于1 μ g/ml放线菌酮（CHX）的人乳腺上皮细胞系MCF 10A诱导的CYP 1A 1 mRNA积累比仅用2，3，7，8-四氯二苯并-对-二恶英（TCDD）获得的高6倍。CHX和TCDD共处理引起CYP 1A 1的超诱导，CYP 1A 1 mRNA的积累比仅用TCDD达到的高30倍。用蛋白质翻译抑制剂茴香霉素（ANS）和嘌呤霉素（PUR）获得了类似的结果。剂量/浓度响应曲线的抑制剂内和抑制剂间比较证明，[H-3]亮氨酸掺入和CYP 1A 1诱导/超诱导之间不存在定量关系。与芳烃受体（AhR）拮抗剂α-萘酮和3 '-甲氧基-4'-硝基黄酮（PD 168641）共孵育抑制CHX的诱导/超诱导活性。电泳迁移率变动分析表明，从CHX处理和CHX+TCDD共处理的培养物的核提取物形成类似的58和类似的340%的AhR/DNA复合物获得与TCDD处理的培养物，分别。与此相反，大鼠肝提取物没有形成AhR/DNA复合物后，在体外转化与CHX。AhR营业额TCDD治疗肝癌1c 1c 7文化受到抑制的共同治疗与CHX。与此相反，CHX或ANS治疗MCF 10A文化诱导AhR损失和增强AhR损失与TCDD共处理的文化。用N-苯甲酰氧羰基-（Z）-Leu-Leu-leucinal（MG 132）而不是来普霉素B共处理抑制AhR损失。因此，在MCF 10A细胞中，CHX不是AhR激动剂，但可以通过AhR依赖性机制超诱导CYP 1A 1;翻译抑制剂对CYP 1A 1的超诱导既不与蛋白质合成的影响定量相关，也不与AhR蛋白水解的普遍预防有关，并且蛋白酶体介导的活化AhR降解可以在细胞核中发生。
Exposure of the human breast epithelial cell line MCF10A to greater than or equal to1 mug/ml cycloheximide (CHX)-induced accumulations of CYP1A1 mRNA 6-fold greater than that achieved with only 2,3,7,8-etrachlorodibenzo-p-dioxin (TCDD). Cotreatment with CHX and TCDD caused superinduction of CYP1A1 with accumulations of CYP1A1 mRNA 30-fold greater than that achieved with only TCDD. Similar results were obtained with the protein translation inhibitors anisomycin (ANS) and puromycin (PUR). Intra- and interinhibitor comparisons of dose/concentration response curves demonstrated the absence of a quantitative relationship between [H-3] leucine incorporation and CYP1A1 induction/superinduction. The inducing/superinducing activities of CHX were suppressed by coincubation with the aryl hydrocarbon receptor (AhR) antagonists alpha-naphthoflavone and 3'-methoxy-4'-nitroflavone (PD168641). Electrophoretic mobility shift assays demonstrated that nuclear extracts from CHX-treated and CHX+TCDD cotreated cultures formed similar to58 and similar to340% of the AhR/DNA complexes obtained with TCDD-treated cultures, respectively. In contrast, rat liver extracts did not form AhR/DNA complexes after in vitro transformation with CHX. AhR turnover in TCDD-treated hepatoma 1c1c7 cultures was suppressed by cotreatment with CHX. In contrast, CHX or ANS treatment of MCF10A cultures induced AhR loss and enhanced AhR loss in cultures cotreated with TCDD. Cotreatment with N-benzoyloxycarbonyl-(Z)-Leu-Leu-leucinal (MG132) but not leptomycin B suppressed AhR loss. Hence, in MCF10A cells, CHX is not an AhR agonist but can superinduce CYP1A1 via an AhR-dependent mechanism; CYP1A1 superinduction by translation inhibitors is neither quantitatively related to effects on protein synthesis nor due to a generalized prevention of AhR proteolysis, and proteasome-mediated degradation of the activated AhR can occur in the nucleus.