A Dual Recognition-Enabled Amplification (DREAM) Strategy Based on Proximity Ligation-Mediated DNA Cascade Circuit for Extracellular Vesicle Detection and Cancer Diagnosis

Tumor-derived extracellular vesicles (tEVs) are potential biomarkers for noninvasive cancer diagnosis. However, accurate and sensitive detection of tEVs is hampered by their high heterogeneity, as well as the potential interference from biological samples. Herein, a d ual r ecognition- e nabled am plification (DREAM) strategy is established, which employs dual aptamers to specifically recognize two exosomal membrane proteins, initiating a proximity ligation-mediated self-reproducing DNA cascade circuit based on catalytic hairpin assembly (CHA) for fluorescence detection of tEVs. Taking tEVs derived from a pancreatic cancer cell line as a model, this assay achieves sensitive, specific, and accurate detection of tEVs in clinical serum samples, accurately differentiating pancreatic cancer patients from healthy donors and other cancer patients. In addition, through simply customizing the dual-recognition sequences, the proposed method is versatilely applied to detect tEVs from different cancer cells (e.g., cervical cancer cells). Overall, the proposed DREAM strategy provides a dream method to detect tEVs for noninvasive cancer diagnosis.