Circ-ABCB10 promotes proliferation and invasion of esophageal squamous cell carcinoma cells by modulating microRNA-670-3p.

OBJECTIVE Circ-ABCB10 is a non-coding RNA newly discovered in recent years. It has been observed to serve as an oncogene in a variety of tumors, but its biological function in esophageal squamous cell carcinoma (ESCC) is still unknown. The purpose of this study was to investigate the circ-ABCB10 expression in ESCC and its possible molecular mechanism. PATIENTS AND METHODS Circ-ABCB10 expression in ESCC tissue samples and cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The impacts of circ-ABCB10 on the biological functions of ESCC cells were examined by cell counting kit-8 (CCK-8) and transwell assays. Moreover, bioinformatics analysis was used to determine the binding sites between miRNAs and circ-ABCB10, and the binding relationship was verified by qRT-PCR and Luciferase assay. RESULTS QRT-PCR analysis revealed that circ-ABCB10 expression in both ESCC tissues and cell lines was higher than that in the normal control group. Patients in high TNM stage exhibited a higher expression of circ-ABCB10 than those in low stage, and this high expression predicted a poor prognosis of ESCC patients. Inhibiting circ-ABCB10 expression remarkably inhibited the growth and metastasis of ESCC cells. In addition, it was demonstrated that circ-ABCB10 could bind to microRNA-670-3p and inhibit its expression. Downregulation of microRNA-670-3p partially reversed the inhibitory impact of low-expressing circ-ABCB10 on cell growth and migration rate. CONCLUSIONS Circ-ABCB10 accelerates the metastasis and proliferation of ESCC cells by binding to microRNA-670-3p. This circ-ABCB10 / microRNA-670-3p axis may become a potential therapeutic target for ESCC therapy.