Objective To analyze the expression of interferon-γ (IFN-γ), interleukin-4 (IL-4), and SRY-related HMG box gene 2 (SOX-2) in gastric cancer and their correlations with helicobacter pylori (HP) infection.

Methods A total of 67 cases of gastric cancer (gastric cancer group), 85 cases of gastritis (gastritis group), and 73 cases of gastric ulcer (ulcer group) were included. The protein expression of IFN-γ, IL-4, and SOX-2 was detected by immunohistochemistry, and the relationship between their positive rates and HP infection was analyzed.

Results The positive rate of HP in gastritis group (91.8%, 78/85) was significantly higher than that in gastric cancer group (79.1%, 53/67) and ulcer group (74.0%, 54/73), with statistically significant differences (P < 0.05). There was no significant difference in the positive rate of HP between gastric cancer and ulcer groups (P < 0.05). The expression of IFN-γ protein was strongly positive in gastric cancer group, weakly positive in gastritis and ulcer groups. Protein expression of IL-4 and SOX-2 was weakly positive in gastric cancer group, but strongly positive in the gastritis and ulcer groups. The positive rate of IFN-γ protein in gastric cancer group was higher than that in gastritis group and ulcer groups (P < 0.05). HP infection in gastric cancer was negatively correlated with SOX-2 protein expression in tissues (r=-0.732, P < 0.05), and was not significantly correlated with IFN-γ and IL-4 protein expression.

Conclusions There may be relationship between occurrence and development of gastric cancer and the up-regulated protein expression of IFN-γ and the down-regulated protein expression of IL4 and SOX-2, and HP infection might promote the occurrence of gastric cancer by affecting the expression of SOX-2 protein.