Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2022 Apr 15;271:120937. doi: 10.1016/j.saa.2022.120937. Epub 2022 Jan 24.
Human telomerase RNA (hTR) is one essential component of telomerase and is overexpressed in tumor cells. Therefore, the reliable and sensitive detection of hTR is essential for the early cancer diagnosis. Herein, to avoid the false positive signals caused by co-existing components in the cell, a ratiometric fluorescence resonance energy transfer (FRET) strategy was developed to achieve reliable detection of intracellular hTR. Manganese dioxide nanosheets (MnONS) with good biocompatibility carry two fluorophore-labelled hairpin DNA probes into the cancer cell and then release the probes via decomposition of MnONS by intracellular L-glutathione reduced (GSH). Then, hTR triggered the cyclic strand displacement reaction (SDR) between two hairpin DNA probes to continuously form DNA duplexes, which made two fluorophores close to each other and led to an effective FRET. Fluorescence imaging demonstrated a higher expression level of hTR in HeLa cells than that in normal HL-7702 cells. The high specificity of hairpin DNA probes and SDR make it easy to discriminate the single-base mutation. Therefore, it provides a highly sensitive, simple and reliable method for the extracellular and intracellular detection of hTR.
人端粒酶 RNA（hTR）是端粒酶的一个重要组成部分，在肿瘤细胞中过度表达。因此，可靠和敏感地检测 hTR 对于早期癌症诊断至关重要。在此，为了避免细胞中共存成分引起的假阳性信号，开发了一种比率荧光共振能量转移（FRET）策略，以实现对细胞内 hTR 的可靠检测。具有良好生物相容性的二氧化锰纳米片（MnONS）将两个荧光标记的发夹 DNA 探针带入癌细胞，然后通过细胞内 L-谷胱甘肽还原（GSH）分解 MnONS 释放探针。然后，hTR 触发两个发夹 DNA 探针之间的循环链置换反应（SDR），以连续形成 DNA 双链，使两个荧光体彼此靠近，导致有效 FRET。荧光成像表明 hTR 在 HeLa 细胞中的表达水平高于正常 HL-7702 细胞。发夹 DNA 探针和 SDR 的高特异性使得易于区分单碱基突变。因此，它为 hTR 的细胞外和细胞内检测提供了一种高度灵敏、简单和可靠的方法。
