Relationship between East Asian CagA⁺ Helicobacter pylori infection and expression of apoptosis protein in different gastric mucosal lesions

Objective To observe Helicobacter pylori (Hp) and CagA⁺-East Asian strains infection in different gastric mucosal lesions in Xi'an, and the influence of the infection on the expression of apoptosis proteins (Bax, Bcl-2, Fas and caspase-3) in different gastric mucosa lesions to elucidate the mechanism of gastric carcinogenesis related to Hp and CagA⁺-East Asian strains infection. Methods Gastric mucosal tissues were taken from patients with different gastric mucosal lesions in Xi'an. Confirmed by HE staining, including chronic superficial gastritis (CSG), chronic atrophic gastritis (CAG), chronic atrophic gastritis with dysplasia (Dys), and gastric cancer (GC). Hp infection and CagA⁺-East Asian strains infection were detected by fast urease test and immunohistochemical method. Expressions of Bax, Bcl-2, Fas and caspase-3 in each group were determined using immunohistochemical method. Results (1) The infection rate of Hp and CagA⁺-East Asian strains was the highest in GC group and the lowest in CSG group (P<0.05). (2) The expressions of Bax and Fas were significantly higher in Hp(+) group than in Hp(-) group (P<0.05). The expressions of Bax, Fas and caspase-3 were significantly higher in CagA⁺-East Asian Hp infection group than in non-CagA⁺-East Asian Hp infection group (P<0.05). However, Bcl-2 expression was lower than that in non-CagA⁺-East Asian Hp infection group (P<0.05). (3) The expressions of Bax, Fas and caspase-3 gradually decreased in CAG, Dys and GC groups, but Bcl-2 expression gradually increased. Conclusion Xi'an is an area with high Hp infection, and the majority of HP-infected persons carry East Asian CagA⁺ strains. East Asian CagA⁺ Hp infection can induce apoptosis of gastric mucosa epithelium and ultimately leads to gastric cancer when working with other factors.