Lack of miR-1246 in small extracellular vesicle blunts tumorigenesis of laryngeal carcinoma cells by regulating Cyclin G2.

Small extracellular vesicle (sEV) has precise impacts on tumor microenvironment and play vital functions in intercellular interaction. However, the functional role of sEV miRNA on laryngeal squamous cell carcinoma (LSCC) is largely unresolved. Here, the expression of miR-1246 in LSCC tissues and plasma sEV was examined. The internalization ability of sEV was determined by uptake assay. Then, the source and purity of sEV were checked through RNase and/or pharmacological inhibitors application. The invasion, migration, proliferation, and cell cycle assays were used to determine the altered abilities of miR-1246 in sEV in LSCC. Finally, target gene of miR-1246, Cyclin G2 (CCNG2), was stained immunohistochemically. In addition, the relationship between CCNG2 and clinicopathological features of patients was analyzed. We found that miR-1246 was higher in LSCC tissues and plasma sEV. MiR-1246 was enriched in sEV rather than soluble form. SEV could be internalized into adjacent cells. Lack of miR-1246 in sEV abrogated the tumorigenesis of LSCC. Furthermore, CCNG2 knockdown arrested the cell cycle and correlated to clinicopathological features and prognosis of LSCC patients. Taken together, we found that the function of sEV miR-1246 by regulating CCNG2 is responsible for LSCC advancement with emphasis on the main source of miR-1246 mainly root in sEV rather than in soluble form.