Long-term ethanol consumption promotes hepatic tumorigenesis but impairs normal hepatocyte proliferation in rats
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Data
2011-06-01
Autores
Chavez, Pollyanna R. G.
Lian, Fuzhi
Chung, Jayong
Liu, Chun
Paiva, Sergio Alberto Rupp de [UNESP]
Seitz, Helmut K.
Wang, Xiang-Dong
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Resumo
Chronic and excessive alcohol consumption has been related to an increased risk of several cancers, including that of the liver; however, studies in animal models have yet to conclusively determine whether ethanol acts as a tumor promoter in hepatic tumorigenesis. We examined whether prolonged alcohol consumption could act as a hepatic tumor promoter after initiation by diethylnitrosamine (DEN) in a rat model. Male Sprague-Dawley rats were injected with 20 mg DEN/kg body weight 1 wk before introduction of either an ethanol liquid diet or an isoenergic control liquid diet. Hepatic pathological lesions, hepatocyte proliferation, apoptosis, PPARα and PPARγ, and plasma insulin-like growth factor 1 (IGF-1) levels were assessed after 6 and 10 mo. Mean body and liver weights, plasma IGF-1 concentration, hepatic expressions of proliferating cellular nuclear antigen and Ki-67, and cyclin D1 in ethanol-fed rats were all significantly lower after 10 mo of treatment compared with control rats. In addition, levels of hepatic PPARγ protein, not PPARα, were significantly higher in the ethanol-fed rats after prolonged treatment. Although ethanol feeding also resulted in significantly fewer altered hepatic foci, hepatocellular adenoma was detected in ethanol-fed rats at 10 mo, but not in control rats given the same dose of DEN. Together, these results indicate that chronic, excessive ethanol consumption impairs normal hepatocyte proliferation, which is associated with reduced IGF-1 levels, but promotes hepatic carcinogenesis. © 2011 American Society for Nutrition.
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alcohol, cyclin D1, cycline, diethylnitrosamine, Ki 67 antigen, peroxisome proliferator activated receptor alpha, peroxisome proliferator activated receptor gamma, somatomedin C, alcohol consumption, animal cell, animal experiment, animal tissue, antineoplastic activity, apoptosis, blood sampling, body weight, cell proliferation, controlled study, diet supplementation, drug efficacy, histopathology, liver, liver carcinogenesis, liver cell, liver weight, male, nonhuman, promoter region, protein blood level, protein expression, rat, Alcoholism, Animals, Apoptosis, Carcinogens, Cell Proliferation, Diethylnitrosamine, Ethanol, Hepatocytes, Insulin-Like Growth Factor I, Ki-67 Antigen, Liver Neoplasms, Experimental, Male, PPAR alpha, PPAR gamma, Proliferating Cell Nuclear Antigen, Rats, Rats, Sprague-Dawley, Animalia, Rattus
Como citar
Journal of Nutrition, v. 141, n. 6, p. 1049-1055, 2011.