Activating gene expression in mammalian cells with promoter-targeted duplex RNAs
Activating gene expression in mammalian cells with promoter-targeted duplex RNAs
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DOI：
10.1038/nchembio860
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发表时间：
2007-03-01
影响因子：
14.8
通讯作者：
Corey, David R.
中科院分区：
文献类型：
--
作者：
Janowski, Bethany A.;Younger, Scott T.;Corey, David R.
选择性激活或抑制基因表达的能力是理解复杂细胞系统和开发治疗方法的基础。最近的研究表明，在哺乳动物细胞中，与染色体DNA内的启动子互补的双链RNA是有效的基因沉默剂。在这里，我们报告，染色体靶向RNA也激活基因表达。我们已经鉴定了与孕酮受体（PR）启动子互补的多个双链RNA，其在转染到培养的T47 D或MCF 7人乳腺癌细胞中后增加PR蛋白和RNA的表达。PR蛋白的上调降低了编码环加氧酶2的下游基因的表达，但没有改变雌激素受体的浓度，这表明激活RNA可以可预测地操纵生理相关的细胞途径。激活随时间推移而降低，并且具有序列特异性。染色质免疫沉淀分析表明，激活是伴随着减少乙酰化在组蛋白H3 K9和H3 K14和增加二-和三甲基化在组蛋白H3 K4。这些数据表明，与蛋白质、激素和小分子一样，小双链RNA在启动子处相互作用，可以激活或抑制基因表达。
The ability to selectively activate or inhibit gene expression is fundamental to understanding complex cellular systems and developing therapeutics. Recent studies have demonstrated that duplex RNAs complementary to promoters within chromosomal DNA are potent gene silencing agents in mammalian cells. Here we report that chromosome-targeted RNAs also activate gene expression. We have identified multiple duplex RNAs complementary to the progesterone receptor ( PR) promoter that increase expression of PR protein and RNA after transfection into cultured T47D or MCF7 human breast cancer cells. Upregulation of PR protein reduced expression of the downstream gene encoding cyclooygenase 2 but did not change concentrations of estrogen receptor, which demonstrates that activating RNAs can predictably manipulate physiologically relevant cellular pathways. Activation decreased over time and was sequence specific. Chromatin immunoprecipitation assays indicated that activation is accompanied by reduced acetylation at histones H3K9 and H3K14 and by increased di- and trimethylation at histone H3K4. These data show that, like proteins, hormones and small molecules, small duplex RNAs interact at promoters and can activate or repress gene expression.