Differential effect of arecoline on the endogenous dioxin-responsive cytochrome P450 1A1 and on a stably transfected dioxin-responsive element-driven reporter in human hepatoma cells
Differential effect of arecoline on the endogenous dioxin-responsive cytochrome P450 1A1 and on a stably transfected dioxin-responsive element-driven reporter in human hepatoma cells
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DOI：
10.1016/j.jhazmat.2007.07.022
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发表时间：
2007-10-01
影响因子：
13.6
通讯作者：
Tsou, Tsui-Chun
中科院分区：
文献类型：
--
作者：
Chao, How-Ran;Wang, Ya-Fen;Tsou, Tsui-Chun
二恶英反应元件介导的化学激活荧光素酶表达（DRE-CALUX）是检测二恶英水平的替代生物检测方法之一。我们之前已经建立了一个DRE-CALUX细胞系，Huh 7-DRE-Luc，通过使用稳定转染Huh-7细胞与报告质粒（4xDRE-TATA-Luc）携带的DRE-driven萤火虫荧光素酶基因。槟榔碱能抑制2，3，7，8-四氯二苯并-对-二恶英（TCDD）诱导的Huh-7细胞细胞色素P450 1A 1（CYP 1A 1）活性。TCDD激活的芳烃受体（AhR）通过与这些二恶英反应基因启动子区的DRE结合，诱导DRE-CALUX激活和CYP 1A 1基因表达。在本研究中，槟榔碱对TCDD诱导的DRE-CALUX和CYP 1A 1酶在Huh 7-DRE-Luc和Huh-7细胞中的激活的影响，分别进行了检查。研究发现槟榔碱抑制TCDD诱导的CYP 1A 1活化，但增强TCDD诱导的DRE-CALUX活化。这一发现表明槟榔碱对内源性二恶英响应CYP 1A 1和稳定转染的DRE-driven报告人肝癌细胞的差异效应。本研究表明，单独诱导DRE-CALUX不一定与内源性CYP 1A 1基因表达平行，报告基因试验可检测内源性基因中无功能的相互作用。(c)2007 Elsevier B. V.保留所有权利。
Dioxin-responsive element-mediated chemical activated luciferase expression (DRE-CALUX) is one of alternative bioassays for the determination of dioxin levels. We have previously established a DRE-CALUX cell line, Huh7-DRE-Luc, by using stable transfection of Huh-7 cells with a reporter plasmid (4xDRE-TATA-Luc) carrying a DRE-driven firefly luciferase gene. It was also shown that arecoline, a major areca nut alkaloid, inhibited the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced cytochrome P450 1A1 (CYP1A1) activation in Huh-7 cells. The TCDD-activated aryl hydrocarbon receptor (AhR) induces the DRE-CALUX activation and CYP1A1 gene expression via binding to DRE in promoter regions of these dioxin-responsive genes. In the present study, the effect of arecoline on the TCDD-induced activation of DRE-CALUX and CYP1A1 enzyme in Huh7-DRE-Luc and Huh-7 cells, respectively, was examined. It was found that arecoline inhibited TCDD-induced CYP1A1 activation and however enhanced TCDD-induced DRE-CALUX activation. This finding indicates the differential effect of arecoline on the endogenous dioxin-responsive CYP1A1 and on a stably transfected DRE-driven reporter in human hepatoma cells. The present study suggests that induction of DRE-CALUX alone does not necessarily parallel with endogenous CYP1A1 gene expression, and that the reporter assay may detect interactions that are not functional in endogenous gene. (c) 2007 Elsevier B.V. All rights reserved.