Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, PR China.
Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Oct 5;278:121316. doi: 10.1016/j.saa.2022.121316. Epub 2022 May 2.
G-quadruplex DNA has attracted the widespread attention as a novel target of anticancer strategy. Herein, two novel stilbene derivatives 2a and 2b were designed and synthesized under mild reaction conditions, and their interactions with G-quadruplex DNA, cytotoxicity, and distribution in living cells were investigated in detail. Both compounds display a low cytotoxicity and the higher affinity to G-quadruplex DNA than to the other secondary structures, including duplex, single-stranded and i-motif DNA, moreover, the affinity of 2b with m-allyl pyridine salt group to G-quadruplex DNA is about 10-fold stronger than that of 2a with p-allyl pyridine salt group. The interactions of the compounds with the promoter G-quadruplexes are enthalpy-driven by an ITC assay. 2a and 2b not only stabilize the G-quadruplex structure but also induce the G-rich sequences (bcl-2, HRCC and KSS) to fold into the mixed-type G-quadruplex in Na/K free Tris-HCl buffer at pH 7.0, and 2b presents the higher stabilization to G-quadruplex than 2a by a FRET-melting assay. 2b presents a dual-emission at 508 and 600 nm and gives a turn-on and stronger and more sensitive fluorescence response over 2a to the promoter (bcl-2, c-kit 2 and c-myc) and mitochondrial (HRCC and KSS) G-quadruplex DNA at both emission wavelengths, moreover, the peak at 508 nm is blue-shifted to 466 nm after binding to DNA. The blue and red dual-channel CLSM images indicate that 2b is mainly distributed in the mitochondrion of living HepG2 cells. The results show that 2b is a potential dual-channel fluorescent probe for mitochondrial G-quadruplex DNA in living cells.
G-四链体 DNA 作为一种新型抗癌策略的靶标引起了广泛关注。在此，在温和的反应条件下设计并合成了两种新型的二苯乙烯衍生物 2a 和 2b，并详细研究了它们与 G-四链体 DNA 的相互作用、细胞毒性和在活细胞中的分布。这两种化合物均表现出低细胞毒性，且对 G-四链体 DNA 的亲和力高于其他二级结构，包括双链、单链和 i 型 DNA，此外，带有 m-烯丙基吡啶盐基团的 2b 与 G-四链体 DNA 的亲和力比带有 p-烯丙基吡啶盐基团的 2a 强约 10 倍。通过 ITC 测定，化合物与启动子 G-四链体的相互作用是由焓驱动的。2a 和 2b 不仅稳定 G-四链体结构，还在无 Na/K 的 Tris-HCl 缓冲液 (pH 7.0) 中诱导富含 G 的序列 (bcl-2、HRCC 和 KSS) 折叠成混合 G-四链体，通过 FRET-融解测定，2b 对 G-四链体的稳定性高于 2a。2b 在 508nm 和 600nm 处具有双发射，与 2a 相比，2b 对启动子 (bcl-2、c-kit 2 和 c-myc) 和线粒体 (HRCC 和 KSS) G-四链体 DNA 具有更强、更灵敏的荧光响应，并且在结合 DNA 后，508nm 处的峰蓝移至 466nm。蓝红双通道 CLSM 图像表明，2b 主要分布在活 HepG2 细胞的线粒体中。结果表明，2b 是一种潜在的用于活细胞中线粒体 G-四链体 DNA 的双通道荧光探针。
