Circ_0056618 and CXCR4 act as competing endogenous in gastric cancer by regulating miR-206.

Circular RNAs (circRNAs) have proved to play an important role in gastric cancer. In this study, we found that circ_0056618 took part in gastric cancer cell proliferation and survival. The real-time polymerase chain reaction result showed that circ_0056618 was overexpressed in tumor tissues or cells compared with adjacent normal tissues or normal cells and had a negative relationship to gastric cancer patients' survival time. Meanwhile, the inhibition of circ_0056618 suppressed the proliferation and metastasis of gastric cancer cells. Further bioinformatical analysis indicated that circ_0056618 sponged miR-206 to regulate CXCR4 according to the prediction of TargetScan and miRanda. Dual-luciferase reporter assay and Western blot analysis revealed the underlying relationship of circ_0056618, miR-206, and CXCR4. Hence, circ_0056618 negatively regulated miR-206 expression promoting CXCR4 expression. Altogether, circ_0056618 is a potential gastric cancer prognostic marker, as well as a potential therapeutic target to inhibit gastric cancer metastasis.