Effect of Helicobacter pylori infection on expression of Bcl-2 family members in gastric adenocarcinoma

Abstract

Aim: To investigate the effect of Helicobacter pylori (H pylori) infection on the expressions of Bcl-2 family members in gastric adenocarcinoma. Methods: Gastric adenocarcinoma and resection margin tissues of 95 patients were studied. Semi-quantitative RT-PCR was used to measure Bid, Bax and Bcl-2 mRNA expressions. Results: Expressions of Bid and Bax in gastric adenocarcinoma tissues without H pylori infection, with cagA- H pylori infection and cagA+ H pylori infection increased significantly in turn (Bid, 0.304, 0.422 and 0.855 respectively, P<0.05; Bax, 0.309, 0.650 and 0.979 respectively, P<0.05). Bcl-2 mRNA levels increased significantly in gastric adenocarcinoma tissues with cagA- H pylori infection and cagA+ H pylori infection, compared with those without H pylori infection (0.696 and 0.849 vs 0.411, P<0.05). Expressions of Bid, Bax and Bcl-2 in resection margin tissues without H pylori infection, with cagA- H pylori infection and cagA+ H pylori infection increased significantly in turn (Bid, 0.377, 0.686 and 0.939 respectively, P<0.05; Bax, 0.353, 0.645 and 1.001 respectively, P<0.05; Bcl-2, 0.371, 0.487 and 0.619 respectively, P<0.05). In H pylori negative specimens, expressions of Bid and Bax correlated negatively with that of Bcl-2 respectively in adenocarcinoma tissues (Bid vs Bcl-2, r=-0409, P<0.05; Bax vs Bcl-2, r=-0451, P<0.05). In H pylori positive specimens, expressions of Bid and Bax did not correlate with that of Bcl-2 in adenocarcinoma tissues (Bid vs 5 Bcl-2, r=0.187, P>0.05; Bax vs Bcl-2, r=0.201, P>0.05), but correlated positively with that of Bcl-2 respectively in resection margin tissues (Bid vs Bcl-2, r=0.331, P<0.05; Bax vs Bcl-2, r=0.295, P<0.05). Conclusion: H pylori may enhance Bid, Bax and Bcl-2 mRNA levels and cause deregulation of these apoptosis-associated genes expressions, which may play a role during development of gastric adenocarcinoma induced by H pylori.