Figure 3. LncRNA HCG18 functions as a ceRNA to enhance SOX7 expression by competitively sponging miR-21-5p in PM2.5-treated HUVECs. (A) The binding relationship between miR-21-5p and SOX7 3’UTR was predicted online. (B) Dual-luciferase assays indicated that the expression of SOX7 was inhibited by miR-21-5p. (C) The protein expression of SOX7 regulated by miR-21-5p was detected using Western blotting. (D) The mRNA level of SOX7 was decreased by miR-21-5p and increased by overexpression of HCG18. Moreover, miR-21-5p abrogated the up-regulation of SOX7 in HUVECs overexpressing HCG18. (E) The data of Western blotting showed that PM2.5 suppressed SOX7 expression, and HCG18 positively regulated SOX7 expression. In addition, the decreased expression of SOX7 by PM2.5 could be reversed by overexpression of HCG18. *: P<0.05; ***: P<0.001.