Tumor-derived exosomal miR-103a-3p promotes vascular permeability and proliferation by targeting ZO-1 and ACOX-1 in nasopharyngeal carcinoma.

Background: miR-103a-3p has been reported to be a factor leading to poor prognosis in several human malignancies, including nasopharyngeal carcinoma (NPC). Secreted microRNAs containing exosomes may mediate the communication between cancer and stromal cells. The purpose of the current work was to learn more about miR-103a-3p's function in NPC exosomes.

Methods: Transmission electron microscopy and NanoSight analysis were used to verify the existence of exosomes. To determine the relationship between exosomal miR-103a-3p and carcinogenesis in NPC, gain- and loss-of-function studies were carried out. Cell Counting Kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU) cell proliferation assay, colony formation, flow cytometry, trans-endothelial invasion assays, endothelial permeability and cellular immunofluorescence were used to identify roles of exosomal miR-103a-3p in vitro. Zebrafish assay was used to disclose the effect of exosomal miR-103a-3p in vivo. Bioinformatics and dual-luciferase reporter assay were applied to clarify the mechanism of exosomal miR-103a-3p regulating the crosstalk between NPC cells and human umbilical vein endothelial cells (HUVECs).

Results: In the present study, we first demonstrated that the overexpression of exosomal miR-103a-3p improved NPC cell proliferation, migration, and the epithelial-mesenchymal transition (EMT) progression in vitro. Then, we verified that NPC cell-derived exosomal miR-103a-3p destroyed the integrity of the endothelial monolayer in vitro and in vivo by downregulating zonula occludens 1 (ZO-1) expression. Moreover, we revealed that miR-103a-3p containing exosomes facilitated NPC cell proliferation through lipid droplet accumulation by direct target to metabolic enzyme acyl-CoA oxidase 1 (ACOX-1).

Conclusions: Our data demonstrate that exosomal miR-103a-3p can facilitate the development of NPC by regulating the crosstalk between NPC cells and HUVECs. Exosomal miR-103a-3p could potentially serve as a therapeutic target for NPC.