Effects of anti-angiopoietin-2 antibody on vascularization of an implanted model of human colonic carcinoma on chick embryo

Abstract

To establish an implanted model of human colonic carcinoma on chick embryo, and to study the effects of anti-angiopoietin-2 antibody on its vascularization. The human colonic adenocarcinoma cell line HT-29 was transplanted on the chick embryo's chorioallantoic membrane(CAM), and the angiogenesis characteristics were observed by stero-microscope, light microscope and immunohistochemistry. Furthermore, the effects of anti-angiopoietin-2 antibody on angiogenesis and tumor growth were also investigated. Three to seven days after HT-29 cell line was implanted into CAM, tumors grew rapidly and new blood vessels grew toward tumors. Five days after anti-angiopoietin-2 antibody was given, the number of blood vessels in anti-angiopoietin-2 antibody group was significantly down-regulated than that in tumor control group observed by stero-microscope (37.2+/-4.6 vs 56.8+/-7.4, P<0.01), but was up-regulated than that in normal control group (37.2+/-4.6 vs 9.6+/-2.4, P<0.01). Microvessel density(MVD) in anti-angiopoietin-2 antibody group was much lower than that in tumor control group by histological examination (9.6+/-2.4 vs 20.2+/-5.8, P<0.01). Angiopoietin-2 antibody is able to inhibit the angiogenesis induced by colorectal cancer cell line HT-29 obviously. The anti-angiopoietin-2 antibody may be potentially useful for clinical treatment of colonic carcinoma.