Aim: To investigate whether NF-kappaB is activated in human gastric carcinoma tissues and, if so, to study whether there is any correlation between NF-kappaB activity and heparanase expression in gastric carcinoma.
Methods: NF-kappaB activation was assayed by immunohistochemical staining in formalin-fixed, paraffin-embedded specimens from 45 gastric carcinoma patients. Electrophoretic mobility shift assay (EMSA) method was used for nuclear protein from these fresh tissue specimens. Heparanase gene expression was quantified using quantitative RT-PCR.
Results: The nuclear translocation of RelA (marker of NF-kappaB activation) was significantly higher in tumor cells compared to adjacent and normal epithelial cells ((41.3+/-3.52)% vs (0.38+/-0.22) %, t = 10.993, P = 0.000<0.05; (41.3+/-3.52)% vs (0+/-0.31)%, t = 11.484, P = 0.000<0.05). NF-kappaB activation was correlated with tumor invasion-related clinicopathological features such as lymphatic invasion, pathological stage, and depth of invasion (Z = 2.148, P = 0.032<0.05; chi(2) = 8.758, P = 0.033<0.05; chi(2) = 18.531, P = 0.006<0.05). NF-kappaB activation was significantly correlated with expression of heparanase gene (r = 0.194, P = 0.046<0.05).
Conclusion: NF-kappaB RelA (p65) activation was related with increased heparanase gene expression and correlated with poor clinicopathological characteristics in gastric cancers. This suggests NF-kappaB as a major controller of the metastatic phenotype through its reciprocal regulation of some metastasis-related genes.