title: Preventive effects of NSAIDs, NO-NSAIDs, and NSAIDs plus difluoromethylornithine in a chemically induced urinary bladder cancer model.
abstract: Urinary bladder cancer prevention studies were performed with the nonsteroidal anti-inflammatory drugs (NSAID) naproxen (a standard NSAID with a good cardiovascular profile), sulindac, and their nitric oxide (NO) derivatives. In addition, the effects of the ornithine decarboxylase inhibitor, difluoromethylornithine (DFMO), alone or combined with a suboptimal dose of naproxen or sulindac was examined. Agents were evaluated at their human equivalent doses (HED), as well as at lower doses. In the hydroxybutyl(butyl)nitrosamine (OH-BBN) model of urinary bladder cancer, naproxen (400 or 75 ppm) and sulindac (400 ppm) reduced the incidence of large bladder cancers by 82%, 68%, and 44%, respectively, when the agents were initially given 3 months after the final dose of the carcinogen; microscopic cancers already existed. NO-naproxen was highly effective, whereas NO-sulindac was inactive. To further compare naproxen and NO-naproxen, we examined their effects on gene expression in rat livers following a 7-day exposure. Limited, but similar, gene expression changes in the liver were induced by both agents, implying that the primary effects of both are mediated by the parent NSAID. When agents were initiated 2 weeks after the last administration of OH-BBN, DFMO at 1,000 ppm had limited activity, a low dose of naproxen (75 ppm) and sulindac (150 ppm) were highly and marginally effective. Combining DFMO with suboptimal doses of naproxen had minimal effects, whereas the combination of DMFO and sulindac was more active than either agent alone. Thus, naproxen and NO-naproxen were highly effective, whereas sulindac was moderately effective in the OH-BBN model at their HEDs.
authors.affiliation: Chemopreventive Agent Development Research Group, Division of Cancer Prevention, National Cancer Institute, Bethesda, MD 20852. lubetr@mail.nih.gov.
authors.forename: Holly L
authors.initials: HL
authors.lastname: Nicastro
authors.forename: Clinton J
authors.initials: CJ
authors.lastname: Grubbs
authors.forename: M
authors.initials: M
authors.lastname: Margaret Juliana
authors.forename: Ann M
authors.initials: AM
authors.lastname: Bode
authors.forename: Mi-Sung
authors.initials: MS
authors.lastname: Kim
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.forename: Ming
authors.initials: M
authors.lastname: You
authors.forename: Ginger L
authors.initials: GL
authors.lastname: Milne
authors.forename: Daniel
authors.initials: D
authors.lastname: Boring
authors.forename: Vernon E
authors.initials: VE
authors.lastname: Steele
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Lubet
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D018890:Chemoprevention / Q000379:methods; D004353:Drug Evaluation, Preclinical; D000518:Eflornithine / Q000008:administration & dosage*; D005260:Female; D009288:Naproxen / Q000008:administration & dosage / Q000031:analogs & derivatives; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000517:prevention & control*; D009569:Nitric Oxide / Q000008:administration & dosage*; D051381:Rats; D011916:Rats, Inbred F344; D013467:Sulindac / Q000008:administration & dosage; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced / Q000517:prevention & control*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; C111751:naproxen-n-butyl nitrate; D013467:Sulindac; D009569:Nitric Oxide; D009288:Naproxen; D000518:Eflornithine