Huang Wei-Chun, Tseng Ting-Yuan, Chen Ying-Ting, Chang Cheng-Chung, Wang Zi-Fu, Wang Chiung-Lin, Hsu Tsu-Ning, Li Pei-Tzu, Chen Chin-Tin, Lin Jing-Jer, Lou Pei-Jen, Chang Ta-Chau
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
Institute of Biomedical Engineering, National Chung-Hsing University, Taichung 40227, Taiwan.
Nucleic Acids Res. 2015 Dec 2;43(21):10102-13. doi: 10.1093/nar/gkv1061. Epub 2015 Oct 19.
G-quadruplex (G4) is a promising target for anti-cancer treatment. In this paper, we provide the first evidence supporting the presence of G4 in the mitochondrial DNA (mtDNA) of live cells. The molecular engineering of a fluorescent G4 ligand, 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide (BMVC), can change its major cellular localization from the nucleus to the mitochondria in cancer cells, while remaining primarily in the cytoplasm of normal cells. A number of BMVC derivatives with sufficient mitochondrial uptake can induce cancer cell death without damaging normal cells. Fluorescence studies of these anti-cancer agents in live cells and in isolated mitochondria from HeLa cells have demonstrated that their major target is mtDNA. In this study, we use fluorescence lifetime imaging microscopy to verify the existence of mtDNA G4s in live cells. Bioactivity studies indicate that interactions between these anti-cancer agents and mtDNA G4 can suppress mitochondrial gene expression. This work underlines the importance of fluorescence in the monitoring of drug-target interactions in cells and illustrates the emerging development of drugs in which mtDNA G4 is the primary target.
G-四链体（G4）是一种很有前景的抗癌治疗靶点。在本文中，我们提供了首个证据，支持活细胞线粒体DNA（mtDNA）中存在G4。荧光G4配体3,6-双（1-甲基-4-乙烯基吡啶鎓）咔唑二碘化物（BMVC）的分子工程改造，可使其在癌细胞中的主要细胞定位从细胞核转变为线粒体，而在正常细胞中则主要保留在细胞质中。许多具有足够线粒体摄取能力的BMVC衍生物可诱导癌细胞死亡，而不损害正常细胞。对这些抗癌药物在活细胞和来自HeLa细胞的分离线粒体中的荧光研究表明，它们的主要靶点是mtDNA。在本研究中，我们使用荧光寿命成像显微镜来验证活细胞中mtDNA G4的存在。生物活性研究表明，这些抗癌药物与mtDNA G4之间的相互作用可抑制线粒体基因表达。这项工作强调了荧光在监测细胞中药物-靶点相互作用方面的重要性，并说明了以mtDNA G4为主要靶点的新型药物的发展。
