miR‑543 acts as a novel oncogene in oral squamous cell carcinoma by targeting CYP3A5.

MicroRNAs (miRNAs/miRs) are small non‑coding RNAs that can act as oncogenes or tumor‑suppressor genes in human cancer. Previous studies have revealed that abnormal expression of miRNAs is closely associated with tumor cell cycle, differentiation, growth and apoptosis. miR‑543 is expressed abnormally in a wide variety of cancers and has been associated with cellular proliferation, apoptosis, and invasion; however, the effect of miR‑543 remains unknown in oral squamous cell carcinoma (OSCC). In the present study, the expression level of miR‑543 in OSCC cell lines and tissues was investigated by RT‑qPCR. A series of experiments was then performed to elucidate the functions of miR‑543 in OSCC, such as CCK‑8 assay, colony formation assay, flow cytometry, cell cycle distribution assay and cell apoptosis assay and Transwell assay. miR‑543 expression was significantly upregulated in tumors from patients with OSCC and in OSCC cell lines. Overexpression of miR‑543 promoted the proliferation, invasion and migration of OSCC cell lines, and inhibited cell apoptosis. In addition, the present study identified cytochrome P450 family 3 subfamily A member 5 (CYP3A5) as a direct target of miR‑543 using software analysis and dual‑luciferase reporter assays. In conclusion, the results of the present study suggest that miR‑543 acts as a tumor promoter and serves a vital role in OSCC proliferation and invasion. These results confirm that miR‑543 may serve as a potential novel target for the treatment of OSCC.