Laboratory of Biochemistry, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka, Japan.
Chem Biol Interact. 2013 Feb 25;202(1-3):126-35. doi: 10.1016/j.cbi.2012.11.023. Epub 2012 Dec 14.
Monomeric carbonyl reductase 1 (CBR1, SDR21C1) is a member of the short-chain dehydrogenase/reductase superfamily and is involved in the metabolism of anthracycline anti-cancer drugs, prostaglandins, and isatin, which is an endogenous inhibitor of monoamine oxidases. Additionally, cancer progression may be partly regulated by CBR1. In the present study, we screened more than 10 drugs for the induction of the human CBR1 gene to investigate its regulation. Of the drugs, butylated hydroxyanisole (BHA) was found to be an inducer. BHA induced the mRNA and protein expression of CBR1 in hepatoma HepG2 cells. In a luciferase reporter gene assay, the promoter region between -2062 bp and the transcription start site of CBR1 was also activated by BHA. The transcription factor Nrf2 is known to be activated by BHA. There are 2 anti-oxidant responsive elements (ARE) that are bound by Nrf2 in this region. Mutation analyses revealed that one of the AREs participates in the gene regulation of CBR1 by Nrf2. Electrophoretic mobility shift assay revealed that Nrf2 binds the site. Moreover, to determine whether the functional ARE of CBR1 is conserved with the promoter region of homologues in other species, the nucleotide sequences of the functional AREs of the Chcr1 and Chcr2 genes, which are the Chinese hamster homologues of CBR1, were determined. The region has 2 AREs, and these genes were also induced by the forced expression of Nrf2 (cotransfection of pNrf2) in the luciferase reporter gene assay. In conclusion, Nrf2 is a novel transcriptional regulator of CBR1 genes in humans and the Chinese hamster. Because the regulation of CBR1 appears to be important for diseases, the induction of CBR1 by Nrf2 may be a therapeutic target.
单体羰基还原酶 1（CBR1，SDR21C1）是短链脱氢酶/还原酶超家族的成员，参与蒽环类抗癌药物、前列腺素和色氨酸的代谢，色氨酸是单胺氧化酶的内源性抑制剂。此外，癌症的进展可能部分受到 CBR1 的调节。在本研究中，我们筛选了 10 多种药物来诱导人 CBR1 基因，以研究其调控机制。在这些药物中，丁基羟基茴香醚（BHA）被发现是一种诱导剂。BHA 诱导肝癌 HepG2 细胞中 CBR1 的 mRNA 和蛋白表达。在荧光素酶报告基因检测中，CBR1 的启动子区域在-2062bp 到转录起始位点之间也被 BHA 激活。转录因子 Nrf2 已知被 BHA 激活。该区域有 2 个抗氧化反应元件（ARE）被 Nrf2 结合。突变分析表明，其中一个 ARE 参与了 Nrf2 对 CBR1 的基因调控。电泳迁移率变动分析显示 Nrf2 结合该位点。此外，为了确定 CBR1 的功能性 ARE 是否与其他物种同源物的启动子区域保守，确定了 CBR1 的中国仓鼠同源物 Chcr1 和 Chcr2 基因的功能性 ARE 的核苷酸序列。该区域有 2 个 ARE，这些基因也被 Nrf2 的强制表达（pNrf2 的共转染）在荧光素酶报告基因检测中诱导。总之，Nrf2 是人类和中国仓鼠 CBR1 基因的新型转录调节因子。由于 CBR1 的调节似乎对疾病很重要，因此 Nrf2 诱导 CBR1 可能是一个治疗靶点。
