Circ-ABCB10 accelerates the malignant progression of oral squamous cell carcinoma by absorbing miRNA-145-5p.

OBJECTIVE: Previous studies have confirmed the carcinogenic role of circ-ABCB10 in certain types of tumors. However, the role of circ-ABCB10 in oral squamous cell carcinoma (OSCC) has not been reported yet. This report investigated the biological function of circ-ABCB10 in aggravating the progression of OSCC by absorbing microRNA-145-5p (miRNA-145-5p) as a ceRNA. PATIENTS AND METHODS: Relative levels of circ-ABCB10 and miRNA-145-5p in OSCC tissues and cell lines were determined. The potential relation between circ-ABCB10 level and pathological indexes of OSCC patients was analyzed. Regulatory effects of circ-ABCB10 and miRNA-145-5p on proliferative and migratory capacities of CAL-27 and Tca8113 cells were assessed. The interaction between circ-ABCB10 and miRNA-145-5p was examined through dual-luciferase reporter gene assay and Chi-square test. At last, rescue experiments were carried out to uncover the role of the circ-ABCB10/miRNA-145-5p regulatory loop in regulating the progression of OSCC. RESULTS: Circ-ABCB10 was upregulated in OSCC tissues and cells. OSCC patients expressing a high level of circ-ABCB10 presented worse tumor staging and a higher rate of distant metastasis relative to those with low level. Knockdown of circ-ABCB10 attenuated proliferative and migratory capacities in CAL-27 and Tca8113 cells. Besides, miRNA-145-5p was downregulated in OSCC tissues and cells. The knockdown of miRNA-145-5p accelerated OSCC cells to proliferate and migrate. Dual-luciferase reporter gene assay proved the binding between circ-ABCB10 and miRNA-145-5p. Moreover, the miRNA-145-5p level was negatively correlated to circ-ABCB10 level in OSCC tissues. Rescue experiments indicated that miRNA-145-5p knockdown could reverse the regulatory effects of circ-ABCB10 on viability, colony formation, and migratory capacity in OSCC cells. CONCLUSIONS: Circ-ABCB10 is upregulated in OSCC, which is closely related to tumor staging and distant metastasis of OSCC patients. Circ-ABCB10 aggravates the progression of OSCC by absorbing miRNA-145-5p.