MicroRNA-758 Regulates Oral Squamous Cell Carcinoma via COX-2

The present study is to examine the expression of microRNA (miRNA or miR)-758 in tumor tissues, blood, and serum from patients with oral squamous cell carcinoma (OSCC) and try to investigate its regulatory mechanism on OSCC. Twenty-eight OSCC patients and 36 healthy subjects were included in the study. Tumor tissues and tumor-adjacent tissues were collected from OSCC patients. Peripheral blood and saliva were collected from OSCC patients and healthy subjects. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expression of mRNA and microRNA. Western blotting was carried out to measure protein expression in tissues, while ELISA was employed to determine protein content in serum and saliva. Dual luciferase reporter assay was used to identify the direct interaction between COX-2 mRNA and miR-758. COX-2 mRNA and protein expression was elevated in OSCC patients. In addition, expression of miR-758 was decreased in OSCC patients. miR-758 was able to bind with the 3′-UTR seed region of COX-2 mRNA to regulate its expression. The present study demonstrates that increased expression of COX-2 in tumors, serum, and saliva from OSCC patients is correlated with the decrease of miR-758 expression. miR-758 might regulate OSCC via COX-2 and can be used as a potential gene marker for OSCC.