MicroRNA-378 promotes the malignant progression of oral squamous cell carcinoma by mediating FOXN3.

OBJECTIVE: This study aimed to detect the expression of microRNA-378 in OSCC, and further studies its effects on clinicopathology and prognosis of OSCC patients. PATIENTS AND METHODS: Real-Time quantitative Polymerase Chain Reaction (RT-qPCR) was used to detect the expression levels of microRNA-378 in 96 pairs of OSCC tissues and paracancerous tissues. The relationship between microRNA-378 expression and pathological parameters and prognosis of OSCC patients was analyzed. The expression level of microRNA-378 in OSCC cells was detected by RT-qPCR as well. Also, microRNA-378 knockdown expression model was constructed using small interfering RNA in OSCC cell lines CAL-27 and Tca8113. Biological functions of OSCC cells were determined using cell counting kit-8 (CCK-8), colony formation, and transwell assay. Western blot was conducted to detect the protein expression of FOXN3 in OSCC cells. RESULTS: RT-qPCR results showed that the expression level of microRNA-378 in OSCC tissues is remarkably higher than that in paracancerous tissues. Compared with OSCC patients with lower expression of microRNA-378, patients with higher expression of microRNA-378 had higher incidences of lymph node metastasis and distant metastasis, as well as shorter overall survival. MicroRNA-378 knockdown significantly decreased proliferative, invasive, and metastatic abilities of OSCC cells. Western blot results showed that microRNA-378 downregulates FOXN3 expression in OSCC cells. Rescue experiments found that microRNA-378 could regulate FOXN3, thus promoting the malignant progression of OSCC. CONCLUSIONS: MicroRNA-378 is highly expressed in OSCC, which is significantly associated with tumor staging, distant metastasis, and poor prognosis of OSCC. It is shown that microRNA-378 may promote malignant progression of OSCC by regulating FOXN3.