Objective To analyze the expression of uncoupling protein-2(UCP2) in human gastric adenocarcinoma tissues and investigate its correlation with the clinical pathological features and prognosis of gastric cancer patients, and to explore its effect on the proliferation and migration of gastric adenocarcinoma cells.

Methods Totally 142 cases of gastric cancer and randomized 25 cases of normal gastric mucosa tissues in Tianjin Medical University Cancer Institute and Hospital were included. We used immunohistochemical staining to detect the expression of UCP2 and analyze its relationship with clinical pathological features. Kaplan-Meier method and Cox regression analysis were used to explore the correlation between the expression of UCP2 and the survival of gastric cancer patients. Western blot was used to detect UCP2 protein level after UCP2 siRNA transfection into SGC7901 gastric cancer cell lines. EdU assays and scratch assay were used to detect the proliferation and migration abilities.

Results The expression of UCP2 in gastric adenocarcinoma tissues was significantly higher than that in adjacent normal tissues (65.5% vs. 28%, P=0.006). The expression of UCP2 in gastric adenocarcinoma tissues was significantly correlated with tumor infiltration (P=0.024), TNM stage (P=0.002) and lymph node metastasis (P=0.001). The 5-year overall survival of patients with positive UCP2 expression was significantly lower than those without UCP2 expression (P=0.001). Silencing UCP2 expression could significantly inhibit the proliferation and migration abilities of SGC7901 cell lines.

Conclusion Positive UCP2 expression is a prognostic factor of gastric adenocarcinoma patients. UCP2 could stimulate the proliferation and migration of gastric cancer cells.