VEGF-c expression in an in vivo model of orthotopic endometrial cancer and retroperitoneal lymph node metastasis

BACKGROUND Retroperitoneal lymph node (RLN) metastasis is an important indicator of endometrial cancer (EC) prognosis. Because vascular endothelial growth factor c (VEGF-c) is known to influence lymphangiogenesis and thereby lymph node metastasis, this study assessed the relationship of VEGF-c mRNA expression with RLN metastasis in EC. METHODS The uterine muscularis mucosae of New Zealand white rabbits were inoculated with a VX2 tumor cell suspension after which they were sacrificed at 15, 18, 21, 24, 27 and 30 days. Control groups consisted of those receiving no treatment or an injection of saline. EC and metastatic RLN tissues along with peripheral blood samples were collected, and VEGF-c mRNA expression was evaluated using fluorescence real-time quantitative PCR. RESULTS The establishment of an in vivo model of EC with complete RLN metastasis was pathologically confirmed at day 21 post-injection with VX2 cells. As compared to the control groups, VEGF-c mRNA expression increased significantly over time in the tumor site, RLN, and peripheral white blood cells of EC rabbits. Significantly higher VEGF-c mRNA expression was observed in metastatic RLNs as compared to those without metastasis (P < 0.001). In addition, increased VEGF-c mRNA expression was observed in peripheral white blood cells of rabbits with RLN metastasis (P < 0.002). CONCLUSION Injection of a VX2 cell suspension is a simple method of establishing an in vivo EC model. VEGF-c may play an important role in the development of EC and its metastasis to RLN and may be useful marker to predict RLN metastasis.