Effect Of Inhibiting Antiopoietin-2 Gene Expression On Angiogenesis Of Human Hepatocellular Carcinoma

Objective:To investigate the vitro tumorigenicity and angiogenesis effect of inhibiting angiopoietin-2 expression in SMMC7721 hepatocellular carcinoma (HCC) cell line and explore the role of angiopoietin-2 gene in the angiogenesis and metastasis of HCC. Methods:In this study, lipofectamine-induced gene transfection method was used to transfect siRNA gene fragment into SMMC7721 cell line which is proved to have angiopoietin-2 expression. The subclones of transfected cell line were selected by G418. Immunofluorescence method proved the expression of angiopoietin protein on SMMC7721 cell line from protein level and RT-PCR proved the angiopoietin expression from the RNA level.Then the HCC cells were subcutaneously injected into 63 nude mice.The tumor growth speed and amount of new vascularization were determined every 2 days for 3 weeks. Results:The tumor grew slower and was smaller in the transfected mice than in non-transfected ones with angiopoietin-2 expression.The average number of newly formed vessels in the non-transfected mice was 7±4.7/HP,9±6.5/HP,19±6.6/HP at the end of the 1st,2nd and 3rd week, respectively. In the transfected group,it was 6±2.5/HP,7±4.2/HP and 10±3.7/HP, respectively.There was significant difference between the two groups (p＜0.05). Conclusions:The angiopoietin-2 gene may play an important role in the growth and progression of HCC and the effect of promoting angiogenesis of the tumor could be weakened by inhibiting the expression of angiopoietin-2 gene.