Understanding the mechanism(s) of anticarcinogenic and procarcinogenic effects of beta-carotene is important due to continuing interest in the potential use of carotenoids as chemopreventive agents -- and the conflicting results of observational studies vs. intervention trials. In the last grant period, our studies indicate that a biologic basis for the harmful effect of beta-carotene supplementation in smokers is related to the high dosage used and the enhanced formation of reactive beta-carotene metabolites in the free-radical-rich, but antioxidant-poor environment of the lungs of cigarette smokers. A mechanism to explain the instability of the beta-carotene molecule is that exposure of lung cells to smoke results in increased lung cell oxidative stress, thereby causing decreased tissue levels of other important antioxidants, such as ascorbate and alpha-tocopherol, which have a stabilizing effect on unoxidized beta-carotene. In the present grant, we propose to conduct an intervention to investigate possible protective effects of a rational combination of linked antioxidants (beta-carotene, vitamins C and E) against cigarette smoke-induced lung lesions in the ferret model. These studies will provide important information on the potential future use of rational antioxidant combinations against lung cancer as well as other tissue.
Our specific aims are as follows: 1) To determine the effectiveness of beta-carotene in both physiologic (low) and pharmacological (high) doses in the presence of vitamins C and E as anti-proliferative agents in the smoke-exposed ferret by examining A) lung cell proliferation indices (cyclin D1, proliferative cellular nuclear antigen PCNA), and the appearance of squamous metaplasia; B) lung retinoid concentrations and retinoid target gene expressions (RARbeta, MAP kinase phosphatase-1, and Bax-1); C) the Jun N-terminal kinase-dependent (JNK) signaling pathway; and D) apoptosis (Caspase 3 and TUNEL); 2) To determine if there is a dose-dependent relationship between beta-carotene intake in the presence of vitamins C and E and oxidative stress by examining A) beta-carotene, vitamin E and vitamin C concentrations in both plasma and lung tissue; and B) the degree of oxidative stress status by measuring isoprostane and malondialdehyde levels in both plasma and lung tissue of ferret; and 3) To determine if vitamins C and E will inhibit the formation of oxidative metabolites from beta-carotene via in vitro incubation studies using the post-nuclear fraction of ferret lungs. We will also determine whether beta-carotene 9?10?-dioxygenase in the ferret lung is involved in metabolism of beta-carotene into apo-carotenals by examining A) expression of beta-carotene 9?10'?-dioxygenase in the ferret lung tissue after treatment with smoke, pharmacological beta-carotene supplementation, or a combination of both in vivo; and B) whether additional supplementation of vitamins C and E in the smoke-exposed ferret with or without beta-carotene supplementation will regulate the expression of beta-carotene 9?10?-dioxygenase and prevent the destruction of beta-carotene both in vivo and in vitro.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA049195-13
Application #
6929760
Study Section
Metabolic Pathology Study Section (MEP)
Program Officer
Kim, Young Shin
Project Start
1991-05-01
Project End
2007-08-31
Budget Start
2005-09-01
Budget End
2007-08-31
Support Year
13
Fiscal Year
2005
Total Cost
$240,000
Indirect Cost
Name
Tufts University
Department
Type
Schools of Medicine
DUNS #
039318308
City
Boston
State
MA
Country
United States
Zip Code
02111
Kim, Yuri; Lian, Fuzhi; Yeum, Kyung-Jin et al. (2007) The effects of combined antioxidant (beta-carotene, alpha-tocopherol and ascorbic acid) supplementation on antioxidant capacity, DNA single-strand breaks and levels of insulin-like growth factor-1/IGF-binding protein 3 in the ferret model of lung cancer. Int J Cancer 120:1847-54
Kim, Yuri; Chongviriyaphan, Nalinee; Liu, Chun et al. (2006) Combined antioxidant (beta-carotene, alpha-tocopherol and ascorbic acid) supplementation increases the levels of lung retinoic acid and inhibits the activation of mitogen-activated protein kinase in the ferret lung cancer model. Carcinogenesis 27:1410-9
Liu, Chun; Russell, Robert M; Wang, Xiang-Dong (2004) Alpha-tocopherol and ascorbic acid decrease the production of beta-apo-carotenals and increase the formation of retinoids from beta-carotene in the lung tissues of cigarette smoke-exposed ferrets in vitro. J Nutr 134:426-30
Liu, Chun; Russell, Robert M; Wang, Xiang-Dong (2004) Low dose beta-carotene supplementation of ferrets attenuates smoke-induced lung phosphorylation of JNK, p38 MAPK, and p53 proteins. J Nutr 134:2705-10
Prakash, Pankaj; Liu, Chun; Hu, Kang-Quan et al. (2004) Beta-carotene and beta-apo-14'-carotenoic acid prevent the reduction of retinoic acid receptor beta in benzo[a]pyrene-treated normal human bronchial epithelial cells. J Nutr 134:667-73
Chung, Jayong; Chavez, Pollyanna R G; Russell, Robert M et al. (2002) Retinoic acid inhibits hepatic Jun N-terminal kinase-dependent signaling pathway in ethanol-fed rats. Oncogene 21:1539-47
Liu, C; Russell, R M; Seitz, H K et al. (2001) Ethanol enhances retinoic acid metabolism into polar metabolites in rat liver via induction of cytochrome P4502E1. Gastroenterology 120:179-89
Chung, J; Liu, C; Smith, D E et al. (2001) Restoration of retinoic acid concentration suppresses ethanol-enhanced c-Jun expression and hepatocyte proliferation in rat liver. Carcinogenesis 22:1213-9
Yeum, K J; dos Anjos Ferreira, A L; Smith, D et al. (2000) The effect of alpha-tocopherol on the oxidative cleavage of beta-carotene. Free Radic Biol Med 29:105-14
Liu, C; Wang, X D; Bronson, R T et al. (2000) Effects of physiological versus pharmacological beta-carotene supplementation on cell proliferation and histopathological changes in the lungs of cigarette smoke-exposed ferrets. Carcinogenesis 21:2245-53

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