Key Laboratory of Breast Cancer in Shanghai, Department of Breast Surgery, Institutes of Biomedical Sciences, Fudan University Shanghai Cancer Center, Shanghai Stomatological Hospital, and Endoscopy Center, Zhongshan Hospital, Fudan University, Shanghai, China.
Department of Chemical Biology, School of Chemistry and Chemical Engineering, and School of Global Health, Shanghai Jiao Tong University, Shanghai, China.
Nat Chem. 2024 Jan;16(1):122-131. doi: 10.1038/s41557-023-01328-5. Epub 2023 Sep 14.
Biomarker discovery is essential for the understanding, diagnosis, targeted therapy and prognosis assessment of malignant diseases. However, it remains a huge challenge due to the lack of sensitive methods to identify disease-specific rare molecules. Here we present MORAC, molecular recognition based on affinity and catalysis, which enables the effective identification of candidate biomarkers with low abundance. MORAC relies on a class of DNAzymes, each cleaving a sole RNA linkage embedded in their DNA chain upon specifically sensing a complex system with no prior knowledge of the system's molecular content. We show that signal amplification from catalysis ensures the DNAzymes high sensitivity (for target probing); meanwhile, a simple RNA-to-DNA mutation can shut down their RNA cleavage ability and turn them into a pure affinity tool (for target pulldown). Using MORAC, we identify previously unknown, low-abundance candidate biomarkers with clear clinical value, including apolipoprotein L6 in breast cancer and seryl-tRNA synthetase 1 in polyps preceding colon cancer.
生物标志物的发现对于恶性疾病的理解、诊断、靶向治疗和预后评估至关重要。然而，由于缺乏灵敏的方法来识别疾病特异性的稀有分子，这仍然是一个巨大的挑战。在这里，我们提出了 MORAC，基于亲和力和催化的分子识别，它能够有效地识别低丰度的候选生物标志物。MORAC 依赖于一类 DNA 酶，它们在特异性感知复杂系统时，会在其 DNA 链中切割嵌入的唯一 RNA 键，而无需事先了解系统的分子内容。我们表明，来自催化的信号放大确保了 DNA 酶的高灵敏度（用于目标探测）；同时，一个简单的 RNA 到 DNA 的突变可以关闭它们的 RNA 切割能力，并将它们转化为纯亲和力工具（用于目标下拉）。使用 MORAC，我们鉴定了具有明确临床价值的以前未知的低丰度候选生物标志物，包括乳腺癌中的载脂蛋白 L6 和结肠癌前息肉中的丝氨酸 tRNA 合成酶 1。
