The human cytochrome Cyp1A2 gene contains regulatory elements responsive to 3-methylcholanthrene.
The human cytochrome Cyp1A2 gene contains regulatory elements responsive to 3-methylcholanthrene.
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人细胞色素 Cyp1A2 基因含有对 3-甲基胆蒽有反应的调节元件。
DOI：
10.1016/s0021-9258(19)38766-6
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发表时间：
1989
影响因子：
3.6
通讯作者：
R. Tukey
中科院分区：
文献类型：
--
作者：
L. Quattrochi;R. Tukey
通过将人细胞色素Cyp1A2基因的5 '侧翼序列转染到人细胞中，研究了3-甲基胆蒽对人细胞色素Cyp1A2基因的调控。Cyp1A2启动子序列和帽位点5 '的3700个碱基与原核氯霉素乙酰转移酶基因连接。将该构建体转染到HepG2细胞中，当用3-甲基胆蒽处理细胞时，Cyp1A2-定向氯霉素乙酰转移酶活性增加2 - 3倍。缺失-1079的侧翼序列导致3-甲基胆蒽诱导的氯霉素乙酰转移酶活性的丧失。当Cyp1A2基因的5 ′-侧翼序列被插入到含有氯霉素乙酰转移酶基因的质粒中时，在猿猴病毒40启动子的控制下，观察到3-甲基胆蒽增强的氯霉素乙酰转移酶活性。最强的3-甲基胆蒽诱导的氯霉素乙酰转移酶活性，4倍的增加，被观察到的DNA片段位于-3202至-1595。当Cyp1A2反应元件被转染到人乳腺癌MCF-7细胞，3-甲基胆蒽没有刺激氯霉素乙酰转移酶活性。相比之下，当分析含有人Cyp1A1外源性反应元件拷贝的DNA片段的增强子活性时，3-甲基胆蒽在HepG2细胞和MCF-7细胞中均启动氯霉素乙酰转移酶活性。这些结果表明，3-甲基胆蒽响应Cyp1A2元件可以在组织特异性的方式进行调节。
The regulation of the human cytochrome Cyp1A2 gene by 3-methylcholanthrene was studied through the transfection of 5'-flanking sequences into human cells. The Cyp1A2 promoter sequence and 3700 bases 5' to the cap site were linked to the procaryotic chloramphenicol acetyltransferase gene. Transfection of this construct into HepG2 cells generated a 2-3-fold increase in Cyp1A2-directed chloramphenicol acetyltransferase activity when the cells were treated with 3-methylcholanthrene. Deletion of flanking sequence to -1079 resulted in a loss of 3-methylcholanthrene-induced chloramphenicol acetyltransferase activity. When 5'-flanking sequences of the Cyp1A2 gene were inserted into a plasmid containing the chloramphenicol acetyltransferase gene under control of the simian virus 40 promoter, 3-methylcholanthrene-enhanced chloramphenicol acetyltransferase activity was observed. The strongest 3-methylcholanthrene-induced chloramphenicol acetyltransferase activity, a 4-fold increase, was observed for a DNA fragment located at -3202 to -1595. When this Cyp1A2 responsive element was transfected into human breast carcinoma MCF-7 cells, 3-methylcholanthrene did not stimulate chloramphenicol acetyltransferase activity. In comparison, when a DNA fragment that contained a copy of the human Cyp1A1 xenobiotic-responsive element was analyzed for enhancer activity, 3-methylcholanthrene initiated chloramphenicol acetyltransferase activity in both HepG2 cells and MCF-7 cells. These results suggest that the 3-methylcholanthrene-responsive Cyp1A2 element may be regulated in a tissue-specific manner.