G-quadruplex (G4) is a four-stranded DNA structure, which is commonly over-represented in gene promoter regions and viewed as an emerging therapeutic target in oncology, as the transcriptional repression of oncogenes through the stabilization of the G4 structure could be a novel anticancer strategy. Traditional Chinese Medicine (TCM), whose agents have diversity in structure and bioactivity, provides an abundant source of G4 ligands. Herein, we present a G4 functionalized magnetic system for screening potential anticancer compounds from TCM. In this system, magnetic microbeads were functionalized with G4 DNA that served as signal molecular nanocarriers. The results showed that the method was able to screen out the targeted molecule(s) with high G4-affinity from the mixture. With the thus established system, several protoberberine alkaloids, the G4 ligands, were successfully screened out from two TCMs, namely, Rhizoma Coptidis and Cortex Phellodendri Chinensis. Compared with the reported screening systems, the G4 functionalized magnetic system developed in this work is simple and easy-to-operate, and can screen out G4-specific binding agents with high specificity and high sensitivity. The method will prospectively promote the discovery of novel active therapeutic drugs or diagnostic probes in the future.

中文翻译：

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G-四链体功能化磁系统从中药中筛选抗癌化合物的新方法

G-四链体（G4）是一种四链DNA结构，通常在基因启动子区域中过量表达，并被视为肿瘤学中新兴的治疗靶标，因为通过稳定G4结构来抑制癌基因的转录可能是新颖的抗癌策略。中药（TCM）的药剂在结构和生物活性方面具有多样性，它提供了丰富的G4配体来源。在这里，我们提出了一种G4功能化的磁性系统，用于从中药中筛选潜在的抗癌化合物。在该系统中，磁性微珠被用作信号分子纳米载体的G4 DNA功能化。结果表明，该方法能够从混合物中筛选出具有高G4亲和力的目标分子。有了这样建立的系统，几种原小ber碱生物碱，黄连和黄柏。与报道的筛选系统相比，这项工作开发的G4功能化磁性系统简单易操作，并且可以高特异性和高灵敏度筛选出G4特异性结合剂。该方法有望在未来促进新型活性治疗药物或诊断探针的发现。