Effect of Avastin on the number and structure of tumor blood vessels of nude mice with A549 lung adenocarcinoma.

The aim of the present study was to investigate the effect of Avastin on the number and structure of tumor blood vessels of nude mice with A549 lung adenocarcinoma. A total of 30 nude mice were randomly divided into three groups, namely the control, the Avastin I (Avastin 3 mg/kg) and the Avastin II (Avastin 6 mg/kg) groups. Following treatment, ELISA was used to detect the expression level of vascular endothelial growth factor (VEGF) in tumor tissues. The microvascular density in tumor tissues and tumor vascular pericyte coverage was detected by immunofluorescence. The tumor growth and survival rate of mice in the three groups were also analyzed. Compared with the control group, the Avastin I and II groups exhibited significantly decreased VEGF levels and microvascular density in the tumor tissues, with the decrease in the Avastin II group being more prominent (P<0.05). After 7 days of treatment, the vascular pericyte coverage in the tumor tissues of mice in the Avastin I and II groups was significantly increased compared with that in the control group mice (P<0.05). Compared with the control group, the mice in the Avastin I and II groups exhibited a significantly decreased tumor growth rate and this effect was dose-dependent. The survival rate of mice in the Avastin I and II groups was significantly increased compared with that of the mice in the control group (P<0.05). In conclusion, Avastin significantly decreased the microvascular density of the tumor in nude mice with A549 lung adenocarcinoma and also significantly increased tumor vascular pericyte coverage, inhibited tumor growth and increased the survival rate of the mice, through its potent antiangiogenic activity.