Objectives: To assess the relationship between the tissue levels of pyrimidine nucleoside phosphorylase (PyNpase) and clinicopathological parameters in human bladder cancer and to investigate the PyNpase levels in rat and mouse urinary bladder initiated by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN).
Methods: The PyNpase levels in tumor tissue, normal tissue adjacent to the tumor, and normal tissue apart from the tumor were measured in 102 patients. Additionally, the PyNpase levels were measured in rat and mouse urinary bladders treated with BBN.
Result: The PyNpase levels of tumor tissue significantly correlated to the tumor grade and growth pattern (papillary/non-papillary), while stage, multiplicity, and tumor shape (peduncle/sessile) were not independent factors. The low-risk tumor of primary, single, G1-Ta showed significantly low levels of PyNpase. The PyNpase levels in the tumor tissue were significantly higher than those in the normal tissue. The PyNpase levels in the adjacent normal tissue were significantly higher than those in the distant normal tissue. The PyNpase levels in rat bladder tissue were significantly higher in the BBN-treatment groups than in those in the control group, only during the early carcinogenic stage. The PyNpase levels in mouse bladder tissue were significantly higher in BBN-treatment groups than in those in the control group during the whole experiment period.
Conclusion: Our results indicated that not only tumor tissue but also normal tissue adjacent to the tumor had a potential of angiogenesis for tumor development, and transurethral resection of the bladder tumor with a wide normal margin seems to be a reasonable strategy for decreasing the risk of recurrence.