Objective: This study aimed to identify the different expression of microRNAs (miRNAs) in the plasma derived exosomes of patients with esophageal squamous cell carcinoma (ESCC).
Patients and methods: A total of 9 patients with ESCC and 9 patients with benign diseases were involved. miRNA sequencing was performed to screen differential expression of microRNAs in plasma exosomes between patients with ESCC and controls. The function of miRNA on proliferation and migration abilities was determined by CCK-8 analysis, wound scratch and transwell test. Predicted target genes were screened by databases and confirmed by RT-qPCR.
Results: We identified a total of 10 miRNAs (7 upregulated and 3 downregulated) that were differentially expressed in plasma exosomes between patients with ESCC and control patients (fold change, FC ≥ 2.0 or ≤ -2.0, p ≤ 0.05) by miRNA sequencing. Ten miRNAs were detected by qRT-PCR to verify the results of the miRNA sequencing. MiR-103a-2-5p demonstrated the most significant differential expression in both exosomes of ESCC cell lines and plasma of patients as compared with control patients and was therefore selected for subsequent functional experiments. Overexpression of miR-103a-2-5p promoted proliferation and migration in TE-1 cells, whereas inhibition of miR-103a-2-5p suppressed proliferation and migration in KYSE-150 cells. Exosomes extracted from the cells transfected with miR-103a-2-5p mimics significantly increased the proliferation and migration of two ESCC cell lines. Two genes, CDH11 and NR3C1 were identified as predicted targets of miR-103a-2-5p by the bioinformatics tools TargetScan, MiRanda, and mirDIP and RT-qPCR.
Conclusions: Our results shed light on how exosomal miR-103a-2-5p can promote proliferation and migration of ESCC cells and may represent a potential target for ESCC therapies.