OP0010 Plasma concentrations of angiopoietin-1, angiopoietin-2, and Tie-2 in gastric cancer

Abstract

Background Angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) have both been identified as ligands for Tie-2, a receptor expressed on endothelial cells. They play critical roles in angiogenesis, in concert with vascular endothelial growth factor (VEGF). Ang-1 binding to Tie-2 maintains and stabilises mature vessels by promoting interactions between endothelial cells and the surrounding extracellular matrix. However, Ang-2 shows context-dependent proangiogenic and antiangiogenic activities. Despite histopathological data reporting differences in the expression of members of the Ang family on the surface of various normal and tumour cells, data for these growth factors in plasma from cancer patients, including gastric cancer, remain scarce. The aims of the present study were to measure the plasma concentrations of Ang-1, Ang-2, and Tie-2 in gastric cancer patients, and to assess the correlation between the concentrations of these factors and the stage of the tumour. Methods The study cohort consisted of 50 patients (33 male, 17 female) with gastric cancer, ranging in age from 38 to 74 years (mean age 55.3 ± 12.4 years), and 50 sex- and age-matched healthy controls. Determinations of Ang-1, Ang-2, and Tie-2 were done with enzyme-linked immunosorbent assay (ELISA). Findings Concentrations of Ang-2 and Tie-2 were significantly higher in patients with gastric cancer than controls, while concentrations of Ang-1 were not significantly different between the groups. Concentrations of Ang-1, Ang-2, and Tie-2 were not significantly different in gastric cancer patients when analysed by different stages of disease. Interpretation Ang-2 and Tie-2 plasma concentrations might be useful tumour markers in gastric cancer.