CRISPR/Cas12a and aptamer-chemiluminescence based analysis for the relative abundance determination of tumor-related protein positive exosomes for breast cancer diagnosis

Exosomes, as novel biomarker for liquid biopsy, exhibit huge important potential value for cancer diagnosis. However, various proteins show different expression levels on exosomal membrane, and the absolute concentration of exosomes in clinical samples is easily influenced by a number of factors. Here, we developed a CRISPR/Cas12a and aptamer-chemiluminescence based analysis (CACBA) for the relative abundance determination of tumor-related protein positive exosomes in plasma for breast cancer diagnosis. The total concentration of exosomes was determined through captured CD63 using a CRISPR/Cas12a-based method with the LoD of 8.97×103 particles/μl. Meanwhile, EpCAM and MUC1 positive exosomes were quantitatively detected by aptamer-chemiluminescence (ACL) based method with the LoD of 1.45×102 and 3.73×102 particles/μl, respectively. It showed that the percentages of EpCAM and MUC1 positive exosomes offered an excellent capability to differentiate breast cancer patients and healthy donors. The high sensitivity, strong specificity, outstanding anti-interference capability, and steady recovery rate of this approach offered higher accuracy and robustness than the commercialized method in clinical trial. In addition with good stability, easy preparation and low cost, this method not only provides a new approach to rapid analysis of exosome proteins, it may be quickly extended to the diagnoses of various cancers.