Expressions of COX-2 and VEGF-C in esophageal squamous cell carcinoma tissues and their correlation with lymphangiogenesis

Objective:To investigate the expressions of cyclooxygenase-2(COX-2) and vascular endothelial growth factor-C(VEGF-C) in esophageal squamous cell carcinoma tissues and their correlation with tumor lymphangiogenesis. Methods: Totally 66 esophageal squamous cell carcinoma specimens were obtained from First Affiliated Hospital of Liaoning Medical University during Jan. 2002 to Jan. 2007, and 10 adjacent tissues were used as control. COX-2 and VEGF-C expressions in esophageal squamous cell carcinoma tissues were detected by SP immunohistochemistry. The lymphangiogenesis of tumor tissue and lymphatic vessel density (LVD) were determined by VEGFR-3 and type Ⅳ collagen immunohistochemical staining, and their relationship with lymph node metastasis was analzyed. Results: The positive rates of COX-2 and VEGF-C in 66 esophageal squamous cell carcinoma tissues (69.70% and 56.06%, respectively) were significantly higher than those in the adjacent tissues (P0.05). The expressions of COX-2 and VEGF-C were remarkably higher in lymph node metastasis positive patients than those in metastasis negative patients (P0.01). Positive correlation was observed between the expression of COX-2 and VEGF-C proteins (r=0.479, P0.05). Significantly higher LVD was observed in COX-2 and VEGF-C double positive patients than in double negative patients (P0.01). Conclusion: COX-2 and VEGF-C are highly expressed in esophageal squamous cell carcinoma tissues, and COX-2 might induce tumor lymphangiogenesis and lymph node metastasis by up-regulating VEGF-C expression.