Research Center of Basic Medicine, Breast Center, Central Hospital Affiliated to Shandong First Medical University, Jinan, 250013, PR China.
School of Chemistry and Chemical Engineering, Shandong University, 250100, Jinan, PR China.
Talanta. 2023 May 15;257:124374. doi: 10.1016/j.talanta.2023.124374. Epub 2023 Feb 18.
Mucin 1 (MUC1) is a transmembrane glycoprotein commonly expressed in epithelial cells with stable levels and polarized distribution. Their expression levels and spatial distribution abnormally altered during oncogenesis and play tumor-promoting roles synergistically. We herein propose a magnetic DNAzyme walker (MDW) for both in-situ imaging and sensitive detection of MUC1. This MDW was constructed by modifying specially designed track strands (TSs) and walking strands (WSs) on a streptavidin magnetic bead (SA-MB). The TSs contained cleavage sites for DNAzymes and were labeled with Cy3 at free ends. The WSs contained DNAzyme sequences and were firstly blocked by hybridizing with Cy5-labeled aptamers of MUC1. The DNAzymes were unlocked upon aptamers binding to MUC1 on cells. MDWs were then transferred to a buffer suitable for DNAzyme action, where the unlocked DNAzymes cleaved multiple TSs, releasing amplified Cy3-fragments, which were separated from the uncleaved ones by magnetic separation. In-situ imaging of MUC1 were achieved by the fluorescence of Cy5 on aptamers bound to MUC1. Sensitive detection of MUC1 were achieved by the amplified fluorescence of released Cy3. In-situ imaging and walker operation for detection were triggered by the same targets at the same time, ensuring the signals are real-time correlative. Moreover, MDWs' operation was separated from cells, reducing interference between imaging and detection. The proposed MDW offers a potential approach for comprehensive analysis of MUC1 in early diagnosis and progression assessment of tumor.
黏蛋白 1（MUC1）是一种跨膜糖蛋白，通常在上皮细胞中表达，具有稳定的水平和极化分布。它们的表达水平和空间分布在癌变过程中异常改变，并协同发挥促进肿瘤的作用。我们在此提出了一种用于 MUC1 的原位成像和灵敏检测的磁性 DNA 酶 walker（MDW）。该 MDW 通过修饰在链霉亲和素磁珠（SA-MB）上的特殊设计的轨迹链（TS）和行走链（WS）构建。TS 包含 DNA 酶的切割位点，在游离端用 Cy3 标记。WS 包含 DNA 酶序列，并首先通过与 MUC1 的 Cy5 标记适体杂交进行阻断。适体与细胞上的 MUC1 结合后，DNA 酶被解锁。MDWs 随后被转移到适合 DNA 酶作用的缓冲液中，在那里，解锁的 DNA 酶切割多个 TS，释放放大的 Cy3 片段，通过磁分离从未切割的片段中分离出来。通过与 MUC1 结合的适体上的 Cy5 的荧光实现 MUC1 的原位成像。通过释放的 Cy3 的放大荧光实现 MUC1 的灵敏检测。原位成像和用于检测的 walker 操作同时由同一靶标触发，确保信号实时相关。此外，MDWs 的操作与细胞分离，减少了成像和检测之间的干扰。该 MDW 为在肿瘤的早期诊断和进展评估中对 MUC1 进行综合分析提供了一种潜在的方法。
