Xia Yaokun, Ju Guomin, Zhou Yongting, Li Xiao, Luo Yufei, Peng Chuanhui, Liu Xueling
Department of Clinical Pharmacy, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China; Zhejiang Provincial Key Laboratory for Drug Evaluation and Clinical Research, Hangzhou, 310003, China.
Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
Anal Chim Acta. 2025 Feb 1;1337:343557. doi: 10.1016/j.aca.2024.343557. Epub 2024 Dec 16.
Amplified imaging of microRNA (miRNA) in cancer cells is essential for understanding of the underlying pathological process. Synthetic catalytic DNA circuits represent pivotal tools for miRNA imaging. However, most existing catalytic DNA circuits can not achieve the reactant recycling operation in cells and in vivo. Additionally, specificity miRNA imaging in tumor site also is a challenge. Herein, inspired by "turning waste into wealth", we report a DNA sensor for imaging of miRNA in target cells based on apurinic/apyrimidinic endonuclease 1 (APE1)-activated reactant recycling catalytic DNA circuit.
The sensing function of the DNA sensor is suppressed firstly through engineering an apurinic/apyrimidinic (AP) site. In the presence of APE1, the AP site undergoes hydrolysis, thereby activating sensing activity and triggering the strand displacement reaction (SDR) under miRNA assistance. In this catalytic DNA circuit, the next reaction cycle can be initiated when the duplex strand waste products are reverted into active components, which allows it to be performed continuously just consuming fuel DNA without depleting the reactant. Noteworthy, the liposome plays important role in overcome biological barriers for nucleic acid delivery. The amplified miRNA imaging strategy is carried out in vivo by this DNA sensor with reducing off-tumor signal under assistance with APE1, and enhances tumor-to-normal tissue contrast compared with traditional catalytic DNA circuit.
Firstly, APE1-activated reactant recycling catalytic DNA circuit is developed. Secondly, miRNA image in cell and in animal is achieved with high spatial selectivity. Thirdly, the signal-to-background ratio for imaging is improved in vitro and in vivo. Lastly, our strategy provides an automatic yet versatile approach for the development of more efficient and selective DNA circuits capable of differentiating miRNA in cancer cells from those in normal cells, promising to be valuable in cancer diagnosis.
癌细胞中微小RNA（miRNA）的放大成像对于理解潜在的病理过程至关重要。合成催化DNA电路是miRNA成像的关键工具。然而，大多数现有的催化DNA电路无法在细胞和体内实现反应物循环操作。此外，在肿瘤部位进行特异性miRNA成像也是一项挑战。在此，受“变废为宝”的启发，我们报道了一种基于脱嘌呤/脱嘧啶内切酶1（APE1）激活的反应物循环催化DNA电路的用于靶细胞中miRNA成像的DNA传感器。
首先通过构建一个脱嘌呤/脱嘧啶（AP）位点来抑制DNA传感器的传感功能。在APE1存在的情况下，AP位点发生水解，从而激活传感活性并在miRNA的辅助下引发链置换反应（SDR）。在这个催化DNA电路中，当双链体废物产物转化为活性成分时，可以启动下一个反应循环，这使得它能够在仅消耗燃料DNA而不消耗反应物的情况下持续进行。值得注意的是，脂质体在克服核酸递送的生物屏障方面发挥着重要作用。这种DNA传感器在体内通过APE1的辅助进行放大的miRNA成像策略，减少了肿瘤外信号，并与传统催化DNA电路相比提高了肿瘤与正常组织的对比度。
首先，开发了APE1激活的反应物循环催化DNA电路。其次，在细胞和动物体内实现了具有高空间选择性的miRNA成像。第三，在体外和体内提高了成像的信号背景比。最后，我们的策略为开发更高效、更具选择性的DNA电路提供了一种自动且通用的方法，能够区分癌细胞和正常细胞中的miRNA，有望在癌症诊断中具有重要价值。
