Tumor cyclooxygenase-2 levels correlate with tumor invasiveness in human hepatocellular carcinoma

AIM: Recent studies suggested that cyclooxygenase-2(COX-2) enhances tumor angiogenesis via upregulationof vascular endothelial growth factor (VEGF). AlthoughCOX-2 expression has been demonstrated in hepatocellularcarcinoma (HCC), the significance of COX-2 in progressionof HCC remains unclear. This study evaluated the clinico-pathological correlation of COX-2 level and its relationshipwith VEGF level in HCC.METHODS: Fresh tumor tissues were obtained from 100patients who underwent resection of HCC. COX-2 proteinexpression was examined by immunohistochemistry, andquantitatively by an enzyme immunometric assay (EIA)of tumor cytosolic COX-2 levels. Tumor cytosolic VEGFlevels were measured by an ELISA.RESULTS: Immunostaining showed expression of COX-2in tumor cells. Tumor cytosolic COX-2 levels correlatedwith VEGF levels (r = 0.469, P＜0.001). Correlation withclinicopathological features showed significantly highertumor cytosolic COX-2 levels in the presence of multipletumors (P = 0.027), venous invasion (P = 0.030),microsatellite lesions (P = 0.037) and advanced tumorstage (P = 0.008). Higher tumor cytosolic COX-2 levelswere associated with worse patient survival.CONCLUSION: This study shows that elevated tumorCOX-2 levels correlate with elevated VEGF levels andinvasiveness in HCC, suggesting that COX-2 plays a significantrole in the progression of HCC.

ABM: Recent studies suggested that cyclooxygenase-2 (COX-2) enhances tumor angiogenesis via upregulation of vascular endothelial growth factor (VEGF). Although COX-2 expression has been demonstrated in hepatocellular carcinoma (HCC), the significance of COX-2 in progression of HCC remains unclear. This study evaluated the clinico-pathological correlation of COX-2 level and its relationship with VEGF level in HCC. METHODS: Fresh tumor tissues were obtained from 100 patients who underwent resection of HCC. COX-2 protein expression was examined by immunohistochemistry, and quantitatively by an enzyme immunometric assay (EIA) of tumor cytosolic COX-2 levels. Tumor cytosolic VEGF levels were measured by an ELISA. RESULTS: Immunostaining showed expression of COX-2 in tumor cells. Tumor cytosolic COX-2 levels correlated with VEGF levels (r = 0.469,P<0.001). Correlation with clinicopathological features showed significantly higher tumor cytosolic COX-2 levels in the presence of multiple tumors (P = 0.027), venous invasion (P = 0.030), microsatellite lesions (P=0.037) and advanced tumor stage (P = 0.008). Higher tumor cytosolic COX-2 levels were associated with worse patient survival. CONCLUSION: This study shows that elevated tumor COX-2 levels correlate with elevated VEGF levels and invasiveness in HCC, suggesting that COX-2 plays a significant role in the progression of HCC.