Fig. 2

H. pylori infection induces GNB4 overexpression in vitro and in vivo. A, B Western blot analysis of GNB4 and CagA protein expression in AGS and MKN45 cells infected with H. pylori SS1 (A) and H. pylori 26695 (B) at different time points. C Western blot analysis of GNB4 protein expression in GES1 cells infected with H. pylori 26695 or H. pylori SS1 for 6 h. D GES1 cells were infected with H. pylori 26695 and H. pylori SS1 for 6 h. Representative images of immunofluorescence staining (scale bars: 25 µm) for GNB4 (red), CagA (purple), and DAPI (blue). E, F IHC score (E) and IHC staining (F) of GNB4 in the PBS group (n = 6), HP (SS1 strain)-infected (n = 6), MNU (n = 6), and HP+MNU (n = 6) mice. Scale bars: 100 μm (inset: 50 μm). G, H IHC staining (G) and IHC score (H) of GNB4 in H. pylori-negative (HP−; n = 40) and H. pylori-positive (HP+; n = 66) patients with GC. I Area under the receiver operator characteristic (ROC) curve for GNB4 in the differential diagnosis of GC with and without H. pylori infection (AUC = 0.6614; P = 0.014). Scale bar: 100 μm (inset: 50 μm). HP, Helicobacter pylori; IHC, immunohistochemistry; MNU, N-methyl-N-nitrosourea; AUC, area under curve