Positive correlation of osteopontin, cyclooxygenase-2 and vascular endothelial growth factor in gastric cancer

Osteopontin (OPN), cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) are overexpressed in various experimental models of malignancy. However, the correlation and role of the three molecules in gastric cancer is unclear. In the present study, we found that OPN, COX-2 and VEGF were overexpressed in 53 cancerous tissues with gastric cancer compared with 40 normal mucosa tissues by immunohistochemistry method. Moreover, the results indicated co-expression of OPN, COX-2, and VEGF in gastric cancer. Levels of OPN, COX-2, and VEGF were all significantly correlated with TNM stage, lymph node metastasis and distant metastasis (P < 0.05), while not related to prognosis of patients. In addition, individual levels of OPN, COX-2, and VEGF were all significantly correlated with microvessel density (MVD), valued by CD34 staining directly with r-values of 0.416, 0.400, and 0.566, respectively (P < 0.01). Both OPN and COX-2 levels showed a positive correlation with VEGF (P < 0.05). Meanwhile, expression of COX-2 is in relation to OPN (P < 0.01). Overall, survival for patients with high MVD was significantly lower than for patients with low MVD (P < 0.05). Our findings indicate that OPN, COX-2, and VEGF synergically promote angiogenesis and metastasis in gastric cancer. It may be an important and useful strategy to target these molecules for prevention and therapy of tumor.