The identification of a specific tumor cell is crucial for the early diagnosis and treatment of cancer. However, it remains a challenge due to the limited sensitivity and accuracy, long response time, and low contrast of the recent approaches. In this study, we develop a dual miRNA-triggered DNA walker (DMTDW) assisted by APE1 for the specific recognition of tumor cells. miR-10b and miR-155 were selected as the research models. Without miR-10b and miR-155 presence, the DNA walker remains inactive as its walking strand of W is locked by L1 and L2. After miR-10b and miR-155 are input, the DNA walker is triggered as miR-10b and miR-155 bind to L1 and L2 of W-L1-L2, respectively, unlocking W. The DNA walker is driven by endogenous APE1 that is highly catalytic and is highly expressed in the cytoplasm of tumor cells but barely expressed in normal cells, ensuring high contrast and reaction efficiency for specific recognition of tumor cells. Dual miRNA input is required to trigger the DNA walker, making this strategy with a high accuracy. The DMTDW strategy exhibited high sensitivity for miRNA analysis with a detection limit of 44.05 pM. Living cell-imaging experiments confirmed that the DMTDW could effectively respond to the fluctuation of miRNA and specifically identified MDA-MB-231 cells from different cell lines. The proposed DMTDW is sensitive, rapid, and accurate for specific tumor cell recognition. We believe that the DMTDW strategy can become a powerful diagnostic tool for the specific recognition of tumor cells.

中文翻译：

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APE1 辅助的双 miRNA 触发 DNA Walker 特异性识别肿瘤细胞

特定肿瘤细胞的鉴定对于癌症的早期诊断和治疗至关重要。然而，由于最近方法的灵敏度和准确性有限、响应时间长以及对比度低，这仍然是一个挑战。在本研究中，我们开发了一种由 APE1 辅助的双 miRNA 触发的 DNA walker (DMTDW)，用于特异性识别肿瘤细胞。选择miR-10b和miR-155作为研究模型。如果没有 miR-10b 和 miR-155 存在，DNA 步行者将保持不活动状态，因为其 W 步行链被 L1 和 L2 锁定。输入 miR-10b 和 miR-155 后，当 miR-10b 和 miR-155 分别与 W-L1-L2 的 L1 和 L2 结合时，DNA walker 被触发，从而解锁 W。 DNA walker 由内源 APE1 驱动，具有高催化性，在肿瘤细胞胞质中高表达，而在正常细胞中几乎不表达，保证肿瘤细胞特异性识别的高对比度和反应效率。触发 DNA walker 需要双 miRNA 输入，使得该策略具有很高的准确性。 DMTDW 策略对 miRNA 分析表现出高灵敏度，检测限为 44.05 pM。活细胞成像实验证实，DMTDW 可以有效响应 miRNA 的波动，并特异性识别来自不同细胞系的 MDA-MB-231 细胞。所提出的 DMTDW 对特定肿瘤细胞识别敏感、快速且准确。我们相信DMTDW策略可以成为特异性识别肿瘤细胞的强大诊断工具。