Next-generation Sequencing for microRNA Profiling: MicroRNA-21-3p Promotes Oral Cancer Metastasis.

Dysfunctional microRNAs (miRNAs) play a crucial role in oral squamous cell carcinoma (OSCC) progression. In the present study, we performed next-generation sequencing for miRNA profiling of the OSCC tissues and corresponding adjacent normal tissues in two patients with OSCC. We observed that 45 miRNAs were substantially up-regulated and 17 miRNAs were down-regulated in OSCC tissues. Since information on the biological role of miR-21-3p (passenger strand) in OSCC is limited, the expression levels of miR-21-3p were further evaluated in 95 OSCC tissue samples by a stem-loop real-time polymerase chain reaction. Our results revealed that miR-21-3p is significantly overexpressed in the OSCC tissues compared with the corresponding adjacent normal tissues (p<0.001). High miR-21-3p expression levels were significantly correlated with N classification (p=0.042). After transfection with a miR-21-3p inhibitor (antagomir), the invasive ability of the OSCC cells was significantly abrogated. Altogether, our findings indicated that miR-21-3p plays a crucial oncogenic role in cell metastasis during OSCC progression.