The growth and angiogenesis inhibition effects of thalidomide combined with radiation on the human esophageal carcinoma transplanted nude mice

Objective: To evaluate the growth and angiogenesis inhibition effects of thalidomide combined with radiation on the nude mouse transplanted with human esophageal carcinoma cells. Methods: Transplant nude mouse model of human esophageal squamous cell carcinoma was established, and 24 nude mice were randomly divided into four groups: healthy control group, thalidomide group, 20 Gy group, and 20 Gy plus thalidomide group. Tumor growth inhibition rates of different groups were calculated. The expressions of vascular epithelial growth factor (VEGF), hypoxia induced factor-1α (HIF-1α) and microvessel density (MVD) were determined by the SP immunohistochemical method. Results: Tumor volume and weigth of 20 Gy + TLD group were significantly lower than those in 20 Gy group (t = 3.68, 4.60, P < 0.05). 20 Gy + TLD treatment yielded the highest tumor inhibitory rate of 60.61%. Both VEGF and HIF-1α expressions and MVD value of 20 Gy group were higher than those of 20 Gy + TLD group (t = 11.82, 6.63, 5.92, P < 0.01). Conclusions: Thalidomide combined with radiation has an increased tumor inhibition effect compared with radiation alone, which may be achieved through VEGF pathway, thalidomide down-regulation of VEGF expression. (authors)