Serum exosomal miR-377-3p and miR-381-3p as diagnostic biomarkers in colorectal cancer

Aim: This study aimed to identify specific and sensitive exosomal miRNAs in diagnosing patients with colorectal cancer (CRC). Methods: Serum exosomes were isolated from 175 CRC patients and 172 healthy donors by ultracentrifugation and identified by transmission electron microscopy, nanoparticle tracking analysis and western blotting. Exosomal miRNA expression was detected by qPCR and the results analyzed by receiver operating characteristic analysis to illuminate the diagnostic accuracy. Results: Both exosomal miR-377-3p and miR-381-3p were downregulated in CRC patients as well as in early-stage patients compared with healthy donors; they could serve as circulating biomarkers of diagnosis, including early diagnosis, for CRC, possessing favorable diagnostic efficiency. Conclusion: Exosomal miR-377-3p and miR-381-3p levels were downregulated in CRC patients and may be useful as novel and specific biomarkers for the diagnosis of CRC, especially early-stage CRC.