Expression of costimulatory molecules B7-H1, B7-H4 and Foxp3+ Tregs in gastric cancer and its clinical significance.

OBJECTIVE: Immune escape plays an important role in tumor progression. In the present study, the expression of B7-H1, B7-H4 and Foxp3 involved in immune escape in gastric carcinoma was investigated and the corresponding clinical significance was evaluated.

METHODS: Immunohistochemistry was used to detect the expression of B7-H1, B7-H4 and Foxp3 in 100 gastric cancer specimens, and 30 paracarcinoma tissues were used as the control.

RESULTS: Both B7-H1 and B7-H4 showed high expression levels in gastric cancer tissues (65.0 and 71.0 %, respectively), and the expressions of B7-H1 and B7-H4 were positively correlated with the depth of tumor invasion, lymph node metastasis and American Joint Committee on Cancer (AJCC) stage (P < 0.05). The number of Foxp3(+) Tregs was much higher in gastric cancer tissues than control tissues, which was positively correlated with lymph node metastasis (P < 0.05). Similarly, a positive correlation between B7-H1 or B7-H4 expression and the number of Foxp3(+) Tregs was observed. The median overall survival rate of patients with high expression of B7-H1, B7-H4 and Foxp3 was significantly poorer than that of patients with low expression of these proteins (P < 0.05). Cox regression multivariate analysis confirmed that lymph node metastasis, AJCC stage, and B7-H1 and Foxp3 overexpression were independent prognostic factors.

CONCLUSION: B7-H1, B7-H4 and Foxp3 were overexpressed in gastric cancer tissues. B7-H1 and Foxp3 are negative prognostic factors for patients with gastric cancer.