The effects of Tim-3 activation on T-cells in gastric cancer progression.

The incidence of gastric cancer is high, especially in China. The present study aims to provide a novel therapeutic target for gastric cancer. Peripheral blood, cancerous and paracancerous tissues were collected from patients with gastric cancer. T-cell immunoglobulin mucin domain-3 (Tim-3) expression in T-cells was measured and the correlation between Tim-3 expression and the T staging of gastric cancer was analyzed. The levels of T-cell secreted interferon (IFN)-γ and tumor necrosis factor (TNF)-α were assessed following Tim-3 signaling pathway activation. A nude mouse model of gastric cancer was established and Tim-3-stimulated T-cells were injected into the mice to evaluate tumor growth. The results of the present study demonstrated that Tim-3 expression levels from the paracancerous and cancerous gastric tissues were significantly increased compared with the peripheral blood, while its expression was significantly increased in cancerous compared with paracancerous gastric tissues. With the T staging of gastric cancer increasing, the expression of Tim-3 gradually increased. The activation of the Tim-3 signaling pathway in T-cells may inhibit IFN-γ and TNF-α secretion, and the results from the nude mice tumor model demonstrated that the inhibitory effect on tumor growth by T-cells was reduced by Tim-3 signaling pathway activation. The expression level of Tim-3 on the surface of tumor infiltrating T-cells in gastric cancer tissue increases significantly and the increased Tim-3 signaling may inhibit the function of T-cells. The results suggest that the increased expression of Tim-3 on T-cells may be involved the development of gastric cancer.