Circular RNA circ_0008305 aggravates hepatocellular carcinoma growth through binding to miR-186 and inducing TMED2.

ABSTRACT

Dysregulation of circRNAs is reported to exert crucial roles in cancers, including hepatocellular carcinoma (HCC). So far, the function of circRNAs in HCC development remains poorly known. Currently, our data showed that circ_0008305 was highly elevated in HCC cell lines and 30 paired tissue samples of HCC. As evidenced, suppression of circ_0008305 repressed HCC cell growth significantly. Meanwhile, up-regulation of circ_0008305 significantly reduced HCC cell growth. Mechanistically, we displayed that circ_0008305 could bind with miR-186 by using bioinformatics analysis. miR-186 has been reported to be a crucial tumour oncogene in many cancers. In addition, we proved miR-186 was greatly decreased in HCC. The direct correlation between miR-186 and circ_0008305 was confirmed in our work. In addition, up-regulation of miR-186 obviously restrained HCC progression. Increased expression of transmembrane p24 trafficking protein 2 (TMED2) is significantly related to the unfavourable outcomes in cancer patients. At our present work, we proved that TMED2 could act as a direct target of miR-186. Mechanistically, we demonstrated that circ_0008305 up-regulated TMED2 expression by sponging miR-186, which resulted in significantly induced HCC progression in vitro and in vivo. These revealed the significant role of circ_0008305 in HCC progression, which might indicate a new perspective on circRNAs in HCC development.