Gastrokine 1 expression in patients with and without Helicobacter pylori infection

Abstract Background To understand the molecular changes underlying Helicobacter pylori -related gastric diseases is mandatory to prevent gastric cancer. Proteomic technology is providing a rapid expansion of the basic knowledge, particularly in the discovery of new biomarkers involved in the tumourigenesis. Aim To characterise changes in protein expression level of the gastric mucosa in H . pylori -infected patients. Methods The population enrolled comprised 41 dyspeptic patients. Proteins extracted from gastric mucosal specimens were analysed by 2-dimensional electrophoresis, sequenced by MALDI-TOF and identified by Edman's degradation. Results Twenty-one out of 41 patients had H. pylori infection of whom 17 had anti-CagA IgG antibodies. Several proteins were identified, of which Rho guanosine diphosphatase dissociation inhibitor α and heat shock protein 27 increased and glutathione transferase and antrum mucosa protein-18 decreased in H . pylori- positive in respect to H . pylori- negative patients. Interestingly, antrum mucosa protein-18, currently referred as gastrokine-1, showed two isoforms differing in the first N-terminal amino acid residue. Both gastrokine-1 isoforms were observed in the H . pylori -negative group whereas a lower expression or even absence of the gastrokine-1 basic isoform was found in a subgroup (7/21) of H . pylori -positive patients with moderate–severe gastritis. Conclusion Our study demonstrated the presence of gastrokine-1 isoforms of which the basic isoform was reduced in a subset of patients with H . pylori infection.