Detoction of Anti-Tumor-Promoters by Soft Agar Colony Forming Assay and Application to Inhibition of Urinary Bladder Carcinogenesis

1990 Fiscal Year Final Research Report Summary

• Project/Area Number: 01570889
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Urology
• Research Institution: Kyoto University
• Principal Investigator: KAKEHI Yoshiyuki Kyoto University, 1. Department Urolgy , Instructor 2. Faculty of Medicine, 医学部, 助手 (20214273)
• Co-Investigator(Kenkyū-buntansha): HORII Yasuki Kyoto University, 1. Department of Urolgy , Instructor 2. Faculty of Medicine, 医学部, 助手 (80211548)
• Project Period (FY): 1989 – 1990
• Keywords: Urinary bladder carcinogenesis / Rat / Inhibitor of Arachidonic acid / Anti-tumor-promoting / NDGA

Research Abstract

Previously, we reported that colony formation in soft agar was shown with rat bladder cells prior to papilloma development in rat treated BBN. And we provided a short-term screening method for detecting new carcinogens, promoters and antiーtumor-promoters. We also evaluated NDG A inhibited saccharin-induced colony formation, suggesting that it has anti-tumor-promoting activity in rat bladder carcinogenesis. We studied long-term experiment on the anti-tumor-promoting effect of NDGA on urinary bladder carcinogenesis in rats induced by BBN. Six-wk-old male Fischer 344 rats were distributed among 8 groups. The were given drinking with (groups 5-8) or without (groups 1-4) 0.05% BBN for 4weeks, and then for 36weeks, they were given powdered diet containing 5% Sodium Saccharin (groups 2and 6). All surviving animals were killed in week 40. Histological abnormalities were investigated. The incidence and numbers of precarcinomatous lesions were significantly lower in group 6 (87%) than 7 (55%). Group 1, 2, 3, and 4 did not show any abnormalities of the bladder epithelium. These results confirm that NDGA have anti-tumor-promoting effects on bladder carcinogenesis in rats.