Expression of angiopoietin-2 gene and its receptor Tie2 in hepatocellular carcinoma

Abstract

To explore the relationship of angiogenesis-related angiopoietin-2 gene and its receptor Tie2 with angiogenesis and the biology, of hepatocellular carcinoma (HOC), angiopoietin-2 gene, Tie2 and CD34 protein expression in 22 resected HOC, 8 cirrhotic and 8 control liver specimens were investigated byin situ hybridization and immunohistochemistry respectively, and the level of angiopoietin-2 and Tie2 expression in HCC were compared in terms of tumor biological parameters. It was found that CD34 was not expressed in control liver, expressed scarcely in cirrhotic liver (17. 8±13.5/HP), but intensively expressed in HCC (86. 3±34. 8/HP,P<0.01). Tie2 receptor was not expressed in controls, expressed at low level in cirrhotic liver (11. 3±8.7/HP), while strongly positive in the microvascular endothelia of HCC (52. 4±16. 7/HP,P<0.01). The level of Tie2 receptor expression in HCC was closely related with tumor diameter, angiogenesis and portal invasion. Angiopoietin-2 gene was not expressed in control liver, expressed mildly in cirrhotic liver (11.2±9. 7/HP), but extensively in tumor zone (36. 4±17. 5/HP), the level of angiopoietin-2 expression was closely related with angiogenesis, portal invasion and histological grading of HCC. It is concluded that angiogenesis is increased in HCC; angiopoietin-2/Tie2 expression in human hepatic carcinoma is closely related with angiogenesis, which are probably involved in the HCC angiogenesis regulation, promoting the development and metastasis of human hepatic cancer.

Keywords

angiopoietin-2 / Tie2 receptor / angiogenesis / carcinoma / hepatocellular

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