Figure 7. circGRAMD1B inhibits the proliferation and invasion of GC cells by modulating miR-130a-3p/PTEN/p21 axis. (A) Western blot assays showed that circGRAMD1B upregulated the protein expression levels of PTEN and p21 in transfected MGC803 and AGS cells. (B) Western blot assays showed that miR-130a-3p decreased the protein expression levels of PTEN and p21 in transfected MGC803 and AGS cells. (C) PTEN and p21 expression was detected via IHC in GC tissues and paired noncancerous tissues. (D) Schematic illustration of PTEN/p21 -3′ UTR-WT and -3′ UTR-MUT luciferase reporter vectors. (E) Luciferase reporter assays demonstrated that PTEN and p21 are direct targets of miR-130a-3p mimics. (F–G) Relative protein expression level of PTEN and p21 were assessed by IF after GC cells transfected with circGRAMD1B-overexpressing plasmid or the silencing siRNA1, and miR-130a-3p mimics or inhibitors. (H) Western blot assays showed that miR-130a-3p could partly decrease the protein expression levels of PTEN and p21, which were promoted by circGRAMD1B. (I) Schematic diagram of the regulatory mechanism of circGRAMD1B/ miR-130a-3p/ PTEN/p21 axis in the inhibition of GC progression. (Values are shown as the mean ± standard error of the mean based on three independent experiments. *P < 0.05, **P < 0.01).