Preferential up-regulation of heparanase and cyclooxygenase-2 in carcinogenesis of Barrett's oesophagus and intestinal-type gastric carcinoma

Aims: Metaplastic changes secondary to chronic inflammation at the gastro-oesophageal junction and at the pyloric antrum are recognized as the premalignant conditions of Barrett's oesophageal adenocarcinoma and intestinal-type gastric carcinoma (GC), respectively. Heparanase (HPSE) and cyclooxygenase (COX)-2 have been proved to play critical roles in inflammation as well as in cancer. The aim was to examine the meaning of their expression in inflammation-related carcinogenesis. Methods and results: First, expression of HPSE and COX-2 in 78 clinical tissues of Barrett's oesophagus was examined by immunohistochemistry and in situ hybridization. Their expression was increased during the metaplasia-dysplasia sequence with increased neovascularization. Successively, their expression in Barrett's dysplasia was compared with that of GC (22 cases of diffuse-type and 10 of intestinal-type). Interestingly, the expression pattern in Barrett's dysplasia was similar to that in intestinal-type GC, which mainly arises from chronic inflammation. Furthermore, cultured cell lines isolated from differentiated GC tissues, which are often found to be of intestinal-type, revealed up-regulated mRNA expression of HPSE and COX-2. Conclusions: HPSE and COX-2 are preferentially up-regulated in Barrett's oesophagus and intestinal-type GC. These molecules may play an important role during the development of inflammation-related adenocarcinoma of the upper gastrointestinal tract.