Heparanase expression in clinical digestive malignancies

Recently, mammalian heparanase was cloned, and its probable function in tumor progression was reported. However, its expression in human clinical cancers has not been fully studied. Thus we determined the heparanase mRNA expression in 30 esophageal cancer cell lines and 144 clinical samples including 38 esophageal squamous cell carcinomas, 71 gastric adenocarcinomas, and 35 colorectal adenocarcinomas. The fresh surgical specimens of cancer tissue (T) and its paired normal tissue (N) were used. The heparanase mRNA was evaluated by reverse transcriptase-polymerase chain reaction, and the T/N expression ratio was determined in clinical cases. All 30 esophageal cancer cell lines expressed heparanase mRNA. The T/N ratio was determined as high (≥1.3), equal (0.8≈1.2) or low (≤0.7) in each clinical case. In cases of esophageal cancer, 7 showed high, 10 equal and 21 low expression. In cases of colorectal cancer, 3 showed high, 16 equal and 16 low expression. On the other hand, 42 showed high, 22 equal and 7 low expression in cases of gastric cancer. The frequency of high expression cases was greater in gastric cancer than in esophageal or colorectal cancers (p<0.05). There were no differences in clinicopathologic factors including prognosis between high and low expression cases of each cancer. Our mRNA study of heparanase indicated that its expression status was different among gastrointestinal cancers. The clinical and pathological impact was low compared to other proteinases, although further studies are recommended for final conclusion.