Molecular Identification of Tumor-Derived Extracellular Vesicles Using Thermophoresis-Mediated DNA Computation

Abstract

Molecular profiling of tumor-derived extracellular vesicles (tEVs) holds great promise for non-invasive cancer diagnosis. However, sensitive and accurate identification of tEVs is challenged by the heterogeneity of EV phenotypes which reflect different cell origins. Here we present a DNA computation device mediated by thermophoresis for detection of tEVs. The strategy leverages the aptamer-based logic gate using multiple protein biomarkers on single EVs as the input and thermophoretic accumulation to amplify the output signals for highly sensitive and specific profiling of tEVs. Employing this platform, we demonstrate a high accuracy of 97% for discrimination of breast cancer (BC) patients and healthy donors in a clinical cohort (n = 30). Furthermore, molecular phenotyping assessed by tEVs is in concordance with the results from tissue biopsy in BC patients. The thermophoresis-mediated molecular computation on EVs thus provides new opportunities for accurate detection and classification of cancers.

Extracellular Vesicles for the Diagnosis of Cancers

“…[184,185] Li et al proposed a thermophoresis-mediated DNA computation device for EV analysis and detection. [186] As shown in Figure 11A, EVs secreted from breast cancer cells carry specific tumor markers, EpCAM and HER2. In the detection process, EVs were first captured on CD63-aptamer-modified microbeads, and in the meantime, two DNA aptamer probes were attached to EpCAM and HER2, initiating an HCR.…”

Recent Progress of Exosome Isolation and Peptide Recognition-Guided Strategies for Exosome Research

“…Compared with antibodies, aptamers and peptides show the advantages of easy chemical synthesis, flexible modification, and high stability, which have expanded their applications in exosome isolation and enrichment ( Zhu L. et al, 2021 ; Chang et al, 2020 ). Li et al modified the microbeads with CD63-aptamers and developed a new thermophoretic aptasensor for the separation and detection of exosomes ( Figure 2B ; Li et al, 2021 ). In this process, exosomes in the samples were first captured by CD63-aptamers to the surface of microbeads.…”

Thermomicrofluidics for biosensing applications

“…Recently, a thermophoresis-mediated DNA computation method has been developed for the detection of multiple protein markers on single EVs. 76 Two breast cancerassociated proteins, EpCAM and HER2, were selected as the inputs of DNA-based AND gate. Two ssDNA strands containing aptamers targeting EpCAM and HER2, space sequences, and associative toehold activation sequences, were used to recognize the target proteins on EV membranes and to initiate the DNA computation.…”