Exosomal miR‐423‐5p Drives Malignant Progression in Esophageal Squamous Cell Carcinoma

Background Exosomes are membrane‐bound vesicles with a diameter of 30–200 nm, and the microRNAs (miRNAs) they carry play important roles in cancer development. This study was aimed at investigating the expression and function of exosomal miRNAs in esophageal squamous cell carcinoma (ESCC). Methods Exosomes were isolated from the plasma of ESCC patients via ultracentrifugation, followed by miRNA sequencing. GO, KEGG, and DO analyses were used to predict potential functions. Engineered exosomes were employed to deliver miR‐423‐5p mimics to ESCC cells, and CCK8, wound healing, transwell, and flow cytometry assays were conducted to evaluate cell proliferation, migration, invasion, and apoptosis. Results Sequencing identified 182 miRNAs, with let‐7b‐5p and miR‐423‐5p being differentially expressed in exosomes from ESCC patients. Functional analysis indicated that these miRNAs may be involved in pathways such as axon guidance and the regulation of stem cell pluripotency. qRT‐PCR validation showed that miR‐423‐5p was downregulated in exosomes from ESCC patients but upregulated in cell lines. Overexpression of miR‐423‐5p suppressed tumor proliferation, migration, and invasion. It is worth noting that the low expression of miR‐423‐5p in ESCC tissues may be related to the increase in exosomal miR‐423‐5p in the local microenvironment, suggesting that tumor cells may export miR‐423‐5p via exosomes to maintain a malignant phenotype. Conclusion Exosomal miR‐423‐5p and let‐7b‐5p play significant roles in the tumor microenvironment of ESCC, and exosome‐mediated delivery of miR‐423‐5p may represent a potential therapeutic strategy.