Characterization of G-quadruplex formation in the ARID1A promoter
Characterization of G-quadruplex formation in the ARID1A promoter
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ARID1A 启动子中 G-四链体形成的表征
DOI：
10.1016/j.ijbiomac.2020.01.210
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发表时间：
2020
影响因子：
8.2
通讯作者：
Guangchao Sui
中科院分区：
文献类型：
--
作者：
Ting Yan;Bo Zhao;Qiong Wu;Wenmeng Wang;Jinming Shi;Dangdang Li;Daniel B. Stovall;Guangchao Sui
作为SWI/SNF家族的一员，ARID1A在调节染色质结构和基因表达方面起着至关重要的作用。ARID1A的肿瘤抑制功能已经被很好地定义，其在癌症中的下调归因于基因组缺失、DNA甲基化和microRNA介导的抑制。在本研究中，我们证明了人类ARID1A转录起始点上游附近富C区的负链可以形成G-四链体。根据该区域的序列合成的寡核苷酸在圆二色谱分析中显示出具有G-四链结构特征的特定波长的摩尔椭圆度。天然聚丙烯酰胺凝胶电泳法、DNA合成阻断法、免疫荧光染色和硫酸二甲酯足迹研究也证明了这些寡核苷酸形成G-四链体。在报告分析中，G-四链形成序列的突变减少了ARID1A启动子介导的转录。转染全长G-四链基序区域的寡核苷酸，而不是其部分序列或突变体，既能促进内源性ARID1A的表达，又能抑制细胞增殖。
As a member of the SWI/SNF family, ARID1A plays an essential role in modulating chromatin structure and gene expression. The tumor suppressive function of ARID1A has been well-defined and its downregulation in cancers is attributed to genomic deletion, DNA methylation and microRNA-mediated inhibition. In this study, we demonstrated that the negative strand of a C-rich region in the upstream vicinity of the human ARID1A transcription start site could form G-quadruplexes. Synthesized oligonucleotides based on the sequence of this region exhibited molar ellipticity at specific wavelengths characteristic of G-quadruplex structures in circular dichroism analyses. The formation of G-quadruplexes by these oligonucleotides were also proved by native polyacrylamide gel electrophoresis, DNA synthesis block assays, immunofluorescent staining and dimethyl sulfate footprinting studies. In reporter assays, mutations of the G-quadruplex forming sequence reduced ARID1A promoter-mediated transcription. Transfection of the oligonucleotide with the full length of G-quadruplex motif region, but not its partial sequences or the mutants, could both promote endogenous ARID1A expression and reduce cell proliferation.