Dickkopf-related protein 1/cytoskeleton-associated protein 4 signaling activation by Helicobacter pylori-induced activator protein-1 promotes gastric tumorigenesis via the PI3K/AKT/mTOR pathway

Figure 2 Helicobacterpylori infection increases JUN and fos-like antigen-1 expression to activate the dickkopf-related protein 1 promoter. A: Western blotting for CagA, p-CagA, JUN, and fos-like antigen-1 (FOSL1) in AGS and SGC-7901 cells infected with Helicobacter pylori (H. pylori) for 6 h. ^aP < 0.05; B: RT-qPCR for JUN and dickkopf-related protein 1 (DKK1) in JUN knockdown and/or H. pylori-infected AGS and SGC-7901 cells. ^aP < 0.05; ^bP < 0.01; C: Western blotting for JUN, p-JUN, and DKK1 in JUN knockdown and/or H. pylori-infected AGS and SGC-7901 cells. ^aP < 0.05; D: RT-qPCR (top) and Western blotting (bottom) for JUN and DKK1 in NCI-N87 and SNU-16 cells with JUN overexpression. ^aP < 0.05; ^cP < 0.001; E: Prediction of AP-1 binding sites in the DKK1 promoter (from -1100 to + 1 bps) by JASPAR; F: JUN and/or FOSL1 promotes DKK1 promoter activity in AGS cells by dual-luciferase reporter assay. The ratio of firefly to Renilla luciferase (Fluc/Rluc) is used to display the results. ^aP < 0.01; ^cP < 0.001; Con: Control; Hp: H. pylori; GZ7: H. pylori GZ7; 26695: H. pylori 26695. FOSL1: Fos-like antigen-1; DKK1: Dickkopf-related protein 1; H. pylori: Helicobacter pylori.