CircCHST15 sponged miR-155-5p and miR-194-5p, and the two miRNAs further targeted PD-L1. (A) Five miRNAs that might be sponged by CircCHST15 were predicted by bioinformatics. (B) The expressions of the five miRNAs (miR-155-5p, miR-671-5p, miR-194-5p, miR-650, and miR-3612) in H1395 cells transfected with CircCHST15 were determined by RT-qPCR, U6 was used as an internal control. (C, F) The binding sites between CircCHST15 with miR-155-5p (C) and between CircCHST15 with miR-194-5p (F) were predicted by bioinformatics. (D, E, G, H) Dual-luciferase reporter assays validated that CircCHST15 sponged miR-155-5p and miR-194-5p in H1395 and A549 cells. (I–L) Biotinylated RNA pull-down assays validated that CircCHST15 sponged miR-155-5p and miR-194-5p in H1395 and A549 cells. (M–P) The binding sites between PD-L1 with miR-155-5p (M) and between PD-L1 with miR-194-5p (P) were predicted by bioinformatics. (N, O, Q, R) Dual-luciferase reporter assays validated that PD-L1 was targeted by miR-155-5p and miR-194-5p in H1395 and A549 cells. (***
P < 0.001, vs. NC; ^^^
P < 0.001, vs. MC; ###
P < 0.001, vs. Biotin-miR-155-5p-WT; &&&
P < 0.001, vs. Biotin-miR-194-5p-WT).