Transcriptional regulation of the canine carbonyl reductase 1 gene (cbr1) by the specificity protein 1 (Sp1).
Transcriptional regulation of the canine carbonyl reductase 1 gene (cbr1) by the specificity protein 1 (Sp1).
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特异性蛋白 1 (Sp1) 对犬羰基还原酶 1 基因 (cbr1) 的转录调节。
DOI：
10.1016/j.gene.2016.08.005
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发表时间：
2016
期刊：
影响因子：
3.5
通讯作者：
Blanco,JavierG
中科院分区：
文献类型：
--
作者：
Quiñones-Lombraña,Adolfo;Cheng,Qiuying;Ferguson,DanielC;Blanco,JavierG
由于心脏毒性的发展，蒽环类药物用于治疗各种犬类癌症的临床应用受到限制。心脏内合成的蒽环素C-13醇代谢物(如柔红霉素)有助于心脏毒性的发展。犬羰基还原酶1(Cbr1)催化柔红霉素还原为柔红霉素醇。最近通过对来自不同品种的狗的DNA样本测序对cbr1基因座进行了定位，发现在cbr1可能的启动子区域有一组转录因子Sp1的保守基序。我们假设Sp1基序的数量可变可能会影响caninecbr1的转录。在这项研究中，我们报告了caninecbr1启动子的功能特征。报告构建和染色质免疫沉淀实验表明，cbr1的转录依赖于Sp1与近端启动子的结合。定点突变实验表明，Sp1基序的数量可变会影响caninecbr1的转录。与对照组相比，Sp1-DNA结合的抑制降低了犬cbr1mRNA水平的54%，也降低了底物柔红霉素(16%)和甲奈二酮(23%)的酶活性。Sp1的反式激活增加了cbr1mRNA的表达(67%)，并增加了柔红霉素(35%)和甲奈二酮(27%)的羰基还原酶活性。这些数据表明，犬类启动子中数量可变的Sp1基序可能会影响蒽环类药物在犬癌患者中的药效学。
The clinical use of anthracyclines to treat various canine cancers is limited by the development of cardiotoxicity. The intra-cardiac synthesis of anthracycline C-13 alcohol metabolites (e.g. daunorubicinol) contributes to the development of cardiotoxicity. Canine carbonyl reductase 1 (cbr1) catalyzes the reduction of daunorubicin into daunorubicinol. Recent mapping of thecbr1locus by sequencing DNA samples from dogs from various breeds revealed a cluster of conserved motifs for the transcription factor Sp1 in the putative promoter region ofcbr1. We hypothesized that the variable number of Sp1 motifs could impact the transcription of caninecbr1. In this study, we report the functional characterization of the caninecbr1promoter. Experiments with reporter constructs and chromatin immunoprecipitation show thatcbr1transcription depends on the binding of Sp1 to the proximal promoter. Site-directed mutagenesis experiments suggest that the variable number of Sp1 motifs impacts the transcription of caninecbr1. Inhibition of Sp1-DNA binding decreased caninecbr1mRNA levels by 54% in comparison to controls, and also decreased enzymatic carbonyl reductase activity for the substrates daunorubicin (16%) and menadione (23%). The transactivation of Sp1 increased the expression ofcbr1mRNA (67%), and increased carbonyl reductase activity for daunorubicin (35%) and menadione (27%). These data suggest that the variable number of Sp1 motifs in the caninecbr1promoter may impact the pharmacodynamics of anthracyclines in canine cancer patients.