A simple, specific and “on-off” type MUC1 fluorescence aptasensor based on exosomes for detection of breast cancer

Numerous studies have demonstrated tumor-derived exosomes (TEX) as an ideal biomarker for cancer. However, most present exosome detection methods were cumbersome and expensive, simple and specific detection of TEX in the blood still remained a challenging task. To solve the above problem, we found firstly that MUC1 was highly expressed on the surface of exosomes secreted by MCF-7 cells compared to other cells. Here, we designed an “on-off”-type aptasensor based on MUC1 activation on TEX. In the absence of TEX, the aptasensor was “off” state. Once in the presence of TEX, the aptasensor recognized the MUC1 on TEX and then turned “on” state, resulting in emitting a fluorescence signal. We used the aptasensor to detect exosomes derived from MCF-7, MCF-7/ADR, A549, MGC-803 and Hs578Bst cells and blood serum from breast cancer patients and healthy donors. The fluorescence signal value of exosomes from serum in breast cancer patients was markedly higher than healthy donors, which were a significant difference between the two groups (P < 0.05). Consequently, the method based on exosomes with high sensitivity, specificity and small amount sample were very likely to be used for breast cancer diagnosis. More importantly, this method can be universally applicable for other tumor diagnosis by changing the aptamer.