Fig. 5

Circ_0000620 served as a molecular sponge of miR-671-5p to regulate MMP2 expression. A, B The subcellular localization of circ_0000620 was analyzed in GC cells using subcellular fractionation assays, with 18 S rRNA and U6 as internal controls. C Venn diagram was performed to analyze the potential miRNAs that bind to circ_0000620 and MMP2. The level of miR-671-5p was tested by qRT-PCR assay in GC tissues and adjacent normal tissues (D), as well as in normal GES-1 cells and GC cells (HGC27 and AGS) (E). F The complementary sites between miR-671-5p and circ_0000620 or MMP2 (MMP2 3΄UTR-1 and MMP2 3΄UTR-2). G The expression of miR-671-5p was detected by qRT-PCR in HGC27 and AGS cells transfected with miR-671-5p mimic, anti-miR-671-5p or corresponding contrasts. H–M Relative luciferase activities in HGC27 and AGS cells co-transfected with circ_0000620 or MMP2 reporters and miR-NC or miR-671-5p were tested through luciferase reporter assay. N–Q RIP assay (N, O) and RNA pull-down assay (P, Q) were used to confirm the interaction between circ_0000620 or MMP2 and miR-671-5p. R and S The protein level of MMP2 was determined by western blot assay after transfection with miR-671-5p mimic, anti-miR-671-5p, sh-circ_0000620 + anti-miR-671-5p or corresponding contrasts. Three repetitions were performed in each experiment, with three parallels every time. *p < 0.05