CHARACTERIZATION OF PYRIMIDINE NUCLEOSIDE PHOSPHORYLASE ACTIVITY IN GASTRIC CARCINOMA

Pyrimidine nucleoside phosphorylase (PyNPase) is an enzyme which catalyzes phosphorolysis of pyrimidine nucleoside, and PyNPase is mainly composed of thymidine phosphorylase (ThdPase), in human carcinoma. Recently it has been repored that ThdPase is identical to platelet-derived endothelial cell growth factor which has as angiogenic activity and ThdPase correlates with metastasis and prognosis in several tu-mors. We examined the activity of PyNPase in 85 cases of gastric carcinoma to investigate whether the activ-ity of PyNPase is related to clinicopathologic factors and prognosis. The activity of PyNPase in gastric cancer tissue is significantly higher than that is normal mucosal tissue. The activity of PyNPase is correlated with liver metastasis, ly factor and v factor. The patients with high PyNPase activity demonstrate worse prognosis than those with low PyNPase activity. Therefore careful follow-up and intensive postoperative adjuvant chemotherapy are required for patients with gastric carcinoma that has a high PyNPase activity.