Expressions Of Angiopoietin-1, -2 And Their Regulation In Gastric Cancer

Angiogenesis is necessary for tumor growth and studies on antiangiogenesis have become one of the most promising and active fields in anticancer research. Increasing evidence shows that Angiopoietin and its receptor Tie2 play pivotal role in tumor angiogenesis. Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2) and their co-receptors Tie2 are involved in vascular remodelling and sprouting, which occur in a complementary and coordinated fashion during vascular development along with VEGF and its receptors. Mounting evidence have confirmed the key roles of Angiopoietin in tumor progression, however, its regulation and mechanisms are still unclear.Cyclooxygenase-2 (COX-2) is generally thought to play important roles in the tumorigensis and progression of many cancers. One of the important mechanisms by which COX-2 acts as a tumor promoter is through the stimulation of angiogenesis. However, the mechanism of COX-2 contribution to tumor angiogenesis and progression is still not fully understood. Our previous study has realved that the expressions of Ang-1 and Ang-2, two main members of Angs family, were found significantly downregulated in COX-2-deprived 7901AS cells compared to its parent cells through gene chip method. In the present study, we aimed to investigate the effect of COX-2 on the expressions of Ang-1 and Ang-2, and then explained its possible mechanisms. In addtion, we detected the potential effect of hypoxia on the expressions of Ang-1 and Ang-2, and investigated...