title: Melatonin suppresses AOM/DSS-induced large bowel oncogenesis in rats.
abstract: The inhibitory effects of exogenous melatonin (MEL) on colon oncogenesis were investigated using an azoxymethane (AOM)/dextran sodium sulfate (DSS) rat model. Male F344 rats initiated with a single intraperitoneal injection of AOM (20mg/kg bw) were promoted by 1% (w/v) DSS in drinking water for 7 days. They were then given 0.4, 2 or 10ppm MEL in drinking water for 17 weeks. At week 20, the development of colonic adenocarcinoma was significantly inhibited by the administration with MEL dose-dependently. MEL exposure modulated the mitotic and apoptotic indices in the colonic adenocarcinomas that developed and lowered the immunohistochemical expression of nuclear factor kappa B, tumor necrosis factor alpha, interleukin-1beta and STAT3 in the epithelial malignancies. These results may indicate the beneficial effects of MEL on colitis-related colon carcinogenesis and a potential application for inhibiting colorectal cancer development in the inflamed colon.
authors.affiliation: Department of Oncologic Pathology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa 920-0293, Japan. takutt@kanazawa-med.ac.jp
authors.forename: Takuji
authors.initials: T
authors.lastname: Tanaka
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Yasui
authors.forename: Mayu
authors.initials: M
authors.lastname: Tanaka
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tanaka
authors.forename: Takeru
authors.initials: T
authors.lastname: Oyama
authors.forename: K M Wahidur
authors.initials: KM
authors.lastname: Rahman
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001397:Azoxymethane / Q000633:toxicity; D014408:Biomarkers, Tumor / Q000378:metabolism; D003106:Colon / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D016264:Dextran Sulfate / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004326:Drinking; D007150:Immunohistochemistry; D007274:Injections, Intraperitoneal; D053583:Interleukin-1beta / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D008940:Mitotic Index; D016328:NF-kappa B / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D050796:STAT3 Transcription Factor / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D053583:Interleukin-1beta; D016328:NF-kappa B; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat; D014409:Tumor Necrosis Factor-alpha; D016264:Dextran Sulfate; D008550:Melatonin; D001397:Azoxymethane