Vascular endothelial growth factor-A and changes in a tumor-bearing mouse model with Lewis lung cancer

Vascular endothelial growth factor-A (VEGF-A) affects tumor growth and metastasis through stimulation of angiogenesis. The purpose of this study was to describe features of Lewis lung cancer (LLC) in mice and compare the serum VEGF-A levels with those of normal control mice. Two groups of mice were compared: one was subcutaneously injected with LLC cells (n=16) and the other served as the normal control (n=6). The serum VEGF-A levels were measured by ELISA prior to inoculation, and at 7, 21 and 35 days post-inoculation. The tumor weight and the metastatic condition were evaluated on day 35. Changes in body weight and serum VEGF-A concentration over a period of time were compared between the groups using generalized estimating equations. The relationship between the primary tumor and the metastatic condition was analyzed using the Spearman's rank correlation test. The survival rate was 56.3% on day 35 post-tumor inoculation. No difference was found between the groups with regard to gastrocnemius muscle weight on day 35 post-inoculation [0.1315±0.0066 g vs. 0.1308±0.0069 g (normal control)]. In tumor-bearing mice, the weight gain at sacrifice was less (0.24±0.45 vs. 1.93±0.47 g, P=0.01), the final mean tumor volume and weight were 4264.69±1038.32 mm(3) and 3.70±0.83 g, the number of nodules in the lungs and livers was 6.33 (range 0-20) and 2.22 (range 0-11), respectively, and the serum VEGF-A levels were significantly higher than those of control mice. In conclusion, lower body weight gain, metastasis in the liver and lungs, and elevated VEGF-A levels are features of LLC in mice.