Institute of Biophotonics, National Yang-Ming University, Taipei 11221, Taiwan, Republic of China, Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan, Republic of China and Department of Chemistry, National Taiwan University, Taipei 106, Taiwan, Republic of China.
Nucleic Acids Res. 2013 Dec;41(22):10605-18. doi: 10.1093/nar/gkt814. Epub 2013 Sep 11.
Guanine-rich oligonucleotides (GROs) are promising therapeutic candidate for cancer treatment and other biomedical application. We have introduced a G-quadruplex (G4) ligand, 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide, to monitor the cellular uptake of naked GROs and map their intracellular localizations in living cells by using confocal microscopy. The GROs that form parallel G4 structures, such as PU22, T40214 and AS1411, are detected mainly in the lysosome of CL1-0 lung cancer cells after incubation for 2 h. On the contrary, the GROs that form non-parallel G4 structures, such as human telomeres (HT23) and thrombin binding aptamer (TBA), are rarely detected in the lysosome, but found mainly in the mitochondria. Moreover, the fluorescence resonant energy transfer studies of fluorophore-labeled GROs show that the parallel G4 structures can be retained in CL1-0 cells, whereas the non-parallel G4 structures are likely distorted in CL1-0 cells after cellular uptake. Of interest is that the distorted G4 structure of HT23 from the non-parallel G4 structure can reform to a probable parallel G4 structure induced by a G4 ligand in CL1-0 living cells. These findings are valuable to the design and rationale behind the possible targeted drug delivery to specific cellular organelles using GROs.
鸟嘌呤富集寡核苷酸（GROs）是一种很有前途的癌症治疗和其他生物医学应用的治疗候选物。我们引入了一种 G-四链体（G4）配体，3,6-双（1-甲基-4-乙烯基吡啶𬭩）咔唑二碘化物，通过共聚焦显微镜来监测裸 GRO 的细胞摄取，并绘制它们在活细胞中的细胞内定位。形成平行 G4 结构的 GRO，如 PU22、T40214 和 AS1411，在孵育 2 小时后主要在 CL1-0 肺癌细胞的溶酶体中被检测到。相反，形成非平行 G4 结构的 GRO，如人类端粒（HT23）和凝血酶结合适体（TBA），很少在溶酶体中被检测到，但主要在线粒体中被发现。此外，荧光共振能量转移研究表明，标记荧光团的 GRO 的平行 G4 结构可以在 CL1-0 细胞中保留，而非平行 G4 结构在细胞摄取后可能在 CL1-0 细胞中发生扭曲。有趣的是，来自非平行 G4 结构的 HT23 的扭曲 G4 结构可以在 CL1-0 活细胞中由 G4 配体重新形成可能的平行 G4 结构。这些发现对于使用 GRO 设计和合理化可能靶向特定细胞细胞器的药物输送具有重要意义。
