Knockdown of TRIM66 inhibits malignant behavior and epithelial-mesenchymal transition in non-small cell lung cancer.

OBJECTIVE: The tripartite motif 66(TRIM66) is an important member of the TRIM protein superfamily, which can participate in the expression of multiple proteins, and is closely associated with the behaviors of non-small cell lung cancer (NSCLC). In this study, we aimed to explore the effect of TRIM66 in this process in vitro using NSCLC cell lines, and the role of TRIM66 in regulating epithelial-mesenchymal transition(EMT) in NSCLC.

METHODS: Western blotting was used to detect the TRIM66 protein expression levels in NSCLC cell lines and normal lung epithelial cells BEAS-2B. We silenced its expression in A549 cells by transient siRNA transfection to ascertain the function of TRIM66 in NSCLC cells. Western blotting was used to detect the expression of EMT-related proteins.

RESULTS: TRIM66 protein content was highest in NSCLC cell line A549, compared with BEAS-2B, it showed that the TRIM66-siRNA group lung cancer cell proliferation was significantly reduced after knockdown of TRIM66, and knockdown of TRIM66 also suppressed invasion, migration and clonogenic ability of A549 cells. Finally, we found that siRNA-mediated TRIM66 silencing suppressed EMT by downregulating expression of N-cadherin and vimentin and upregulating that of E-cadherin in NSCLC cells, which could effectively reduce the invasive, migratory, and proliferative capacities of lung cancer cells.

CONCLUSION: Silence TRIM66 expression suppressed NSCLC cell proliferation, invasion, and migration. The siRNA-mediated TRIM66 silencing could block the occurrence of EMT. TRIM66 could be a promising novel target for future NSCLC treatments.