Figure 7.

The circRNA hg38_circ_0008980 Positively Regulates the Expression of ETV1 via Targeting the miRNA hsa-miR-660-5p

(A and B) The miRNA response elements (MREs) of hsa-miR-660-5p were shown on both the sequence of hg38_circ_0008980 (A) and ETV1 3′ UTR (B), and mutations were introduced on these MREs, respectively. Both wild-type and the mutated sequences were cloned into psiCHECK-2 plasmid. (C and D) Dual-luciferase reporter assays showed that hsa-miR-660-5p transfection significantly decreased the luciferase activity of the wild-type hg38_circ_0008980 (C) or ETV1 3′ UTR (D), while luciferase activities of the mutated constructs were not affected. The relative activities were expressed as the renilla luciferase activity normalized to the firefly luciferase activity. (E) The hg38_circ_0008980 overexpression as well as hsa-miR-660-5p inhibition significantly increased the transcription of ETV1 mRNA, and, in contrast, the hsa-miR-660-5p mimics completely blocked hg38_circ_0008980 overexpression-mediated upregulation of ETV1. Data were expressed as the mean ± SEM from three independent assays. *p < 0.05, **p < 0.01, and ***p < 0.001.