Miglietta Giulia, Gouda Alaa S, Cogoi Susanna, Pedersen Erik B, Xodo Luigi E
Department of Medical and Biological Sciences, University of Udine , 33100 Udine, Italy.
Nucleic Acid Center, Institute of Physics and Chemistry, University of Southern Denmark , DK-5230 Odense M, Denmark.
ACS Med Chem Lett. 2015 Oct 18;6(12):1179-83. doi: 10.1021/acsmedchemlett.5b00315. eCollection 2015 Dec 10.
In a previous study we have demonstrated that two neighboring G-quadruplexes, hras-1 and hras-2, located immediately upstream of the major transcription start site of HRAS, bind MAZ, a nuclear factor that activates transcription (Cogoi, S.; et al. Nucl. Acid Res. 2014, 42, 8379). For the present study we have designed G4 oligonucleotides with anthraquinone insertions and locked nucleic acids (LNA) modifications mimicking quadruplex hras-1. Luciferase, qRT-PCR, and Western blot data demonstrate that these constructs efficiently down regulate HRAS in T24 bladder cancer cells. The inhibitory efficiency of the G4 oligonucleotides correlates with their nuclease resistance in the cell environment. By chromatin immunoprecipitation we show that the association of MAZ to the HRAS promoter is strongly attenuated by the designed G4 oligonucleotides, thus suggesting that these constructs behave with a decoy mechanism.
在之前的一项研究中，我们已经证明，位于HRAS主要转录起始位点上游紧邻位置的两个相邻G-四链体，即hras-1和hras-2，能够结合MAZ，一种激活转录的核因子（科戈伊，S.等人，《核酸研究》，2014年，42卷，8379页）。在本研究中，我们设计了带有蒽醌插入和锁核酸（LNA）修饰的G4寡核苷酸，模拟四链体hras-1。荧光素酶、qRT-PCR和蛋白质印迹数据表明，这些构建体能够有效地下调T24膀胱癌细胞中的HRAS。G4寡核苷酸的抑制效率与其在细胞环境中的核酸酶抗性相关。通过染色质免疫沉淀，我们表明设计的G4寡核苷酸强烈减弱了MAZ与HRAS启动子的结合，因此表明这些构建体以诱饵机制发挥作用。
