OBJECTIVE

To investigate the impact and potential mechanisms of serum extracellular nano-vesicles (sEVs) miR-412-3p released from sub-centimeter lung nodules with a diameter of ⩽ 10 mm on the malignant biological function of micro-nodular lung cancer (mnLC).

METHODS

A total of 87 participants were included and divided into a mnLC group (n= 30), a benign lung nodule (BLN) group (n= 27), and a healthy people control group (n= 30). Transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and Western blot (WB) were used to measure the morphological characteristics and surface markers of sEVs. In vitro analysis, real-time quantitative polymerase chain reaction (RT-qPCR), CCK-8 cell proliferation assay, clone formation assay, Transwell, stem cell sphere-forming assay, and WB assay were conducted to verify the effect of miR-412-3p/TEAD1 signaling axis on the biological function of lung cancer cells through, respectively. Further validation was conducted using the serum sEVs of the participants.

RESULTS

The expression level of sEVs-miR-412-3p in the mnLC group was significantly higher than that in the BLN and healthy groups (P< 0.01). In lung cancer cell lines, miR-412-3p can negatively regulate the targeted gene TEAD1. The miR-412-3p/TEAD1 signaling axis is involved in promoting the EMT signaling pathway and regulating the malignant biological functions of lung cancer cell proliferation, migration, and stemness (P< 0.05). In addition, sEVs in the mnLC group significantly promoted lung cancer cell proliferation, migration, and stemness compared to the BLN and healthy groups, inhibited the expression of E-cadherin and TEAD1 in lung cancer cells, and promoted the expression of N-cadherin and Vimentin (P< 0.05).

CONCLUSION

sEVs-miR-412-3p could promote the biological process of EMT, and lead to the occurrence of malignant biological behavior in sub-centimeter lung nodules. This provides evidence for the miR-412-3p/TEAD1 signaling axis as a potential therapeutic target for mnLC.