Chemopreventive Effects of a Selective Nitric Oxide Synthase Inhibitor on Carcinogen-Induced Rat Esophageal Tumorigenesis
| Autor: | Sarah M. Peschke, Ronald Nines, Laura A. Kresty, Tong Chen, Gary D. Stoner |
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| Rok vydání: | 2004 |
| Předmět: |
Male
Cancer Research Pathology medicine.medical_specialty Esophageal Neoplasms Nitric Oxide Synthase Type II Biology Pharmacology medicine.disease_cause Dimethylnitrosamine Nitric oxide Eating chemistry.chemical_compound medicine Animals Anticarcinogenic Agents Enzyme Inhibitors Esophagus Carcinogen Reverse Transcriptase Polymerase Chain Reaction Body Weight Thiourea Esophageal cancer medicine.disease Rats Inbred F344 Rats Nitric oxide synthase medicine.anatomical_structure Oncology chemistry Tumor progression Toxicity Carcinogens biology.protein Nitric Oxide Synthase Carcinogenesis |
| Zdroj: | Cancer Research. 64:3714-3717 |
| ISSN: | 1538-7445 0008-5472 |
| Popis: | The inducible nitric oxide synthase (iNOS) generates a high concentration of nitric oxide (NO) in tissues. Increased NO production is associated with many disorders including esophageal cancer. Previous studies in our laboratory demonstrated an association between increased iNOS expression and the development of N-nitrosomethylbenzylamine (NMBA)-induced tumors in the rat esophagus. On the basis of these observations, we initiated a bioassay to evaluate the ability of S,S′-1,4-phenylene-bis(1,2-ethanediyl)bis-isothiourea (PBIT), a selective iNOS inhibitor, to prevent the progression of esophageal tumors in rats preinitiated with NMBA. Rats were given s.c. injections of NMBA (0.25 mg/kg body weight) three times per week for 5 weeks. One week later, they were fed a synthetic diet containing either 50 or 100 ppm PBIT until the end of the bioassay (25 weeks). PBIT reduced the incidence of esophageal cancer from 96% in NMBA-treated rats to 83% and 77% (P < 0.05) in rats treated with 50 and 100 ppm PBIT, respectively. Tumor multiplicity was reduced from 3.64 ± 0.42 tumors per esophagus in NMBA-treated rats to 1.79 ± 0.25 (P < 0.001) and 1.50 ± 0.24 (P < 0.0001) in rats treated with 50 and 100 ppm PBIT, respectively. PBIT reduced the production of NO in NMBA-induced preneoplastic and papillomatous esophageal lesions when compared with comparable lesions in rats treated with NMBA only. iNOS mRNA expression was not modulated by PBIT. These observations suggest that iNOS plays a role in tumor development and that its selective inhibitor, PBIT, significantly inhibits esophageal tumor progression presumably through reducing the production of NO. |
| Databáze: | OpenAIRE |
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