TY - JOUR
T1 - Dietary oat lipids-induced novel DNA modifications and suppression of altered hepatic foci formation
AU - Li, Donghui
AU - Wang, Mianying
AU - Paul, Greg
AU - Pitot, Henry C.
AU - Dragan, Yvonne
N1 - Funding Information:
The authors thank Dr. K. Randerath for encouragement and helpful discussion and Dr. Mariza de Andrade for statistical analysis. This project was sponsored by a gift from The Quaker Oats Company. Address reprint requests to Dr. Donghui Li, Dept. of Gastrointestinal Oncology and Digestive Diseases, The University of Texas M. D. Anderson Cancer Center, 1515 Holcome Bl., Box 78, Houston, TX 77030.
PY - 1999
Y1 - 1999
N2 - Previous studies have shown that the presence of several hepatic I- compounds, i.e., age-dependent covalent DNA modifications, is related to the presence of a natural ingredient, i.e., oats, in the diet. To demonstrate the biological significance of these novel DNA modifications, the effect of oat lipids on tumor initiation and promotion was examined in a rat liver tumor model. Female Sprague-Dawley rats were treated with a single dose of diethylnitrosamine, a hepatic carcinogen, 24 hours after a 70% partial hepatectomy, then subjected to dietary phenobarbital promotion. Diets containing 10% oat lipids or corn oil were given during the initiation or the promotion stage of the tumorigenesis. At the end of the feeding, hepatic I- compounds were measured by 32P postlabeling, and the number and volume of enzyme-altered hepatic foci, which served as preneoplastic markers, were measured in serial sections of liver by the method of quantitative stereology. Rats receiving oat lipids-supplemented diets had five- to sixfold higher levels of I-compounds in their liver DNA than those receiving control diets. Meanwhile, rats receiving diets containing oat lipids during promotion had significantly smaller numbers and reduced volume of altered hepatic foci compared with those fed the control diet containing corn oil. These observations support the hypothesis that some I-compounds, e.g., the oats- specific I-compounds, are novel DNA modifications related to nutrient metabolism. The diet containing oat lipids may have chemopreventive activities, as demonstrated in this model system.
AB - Previous studies have shown that the presence of several hepatic I- compounds, i.e., age-dependent covalent DNA modifications, is related to the presence of a natural ingredient, i.e., oats, in the diet. To demonstrate the biological significance of these novel DNA modifications, the effect of oat lipids on tumor initiation and promotion was examined in a rat liver tumor model. Female Sprague-Dawley rats were treated with a single dose of diethylnitrosamine, a hepatic carcinogen, 24 hours after a 70% partial hepatectomy, then subjected to dietary phenobarbital promotion. Diets containing 10% oat lipids or corn oil were given during the initiation or the promotion stage of the tumorigenesis. At the end of the feeding, hepatic I- compounds were measured by 32P postlabeling, and the number and volume of enzyme-altered hepatic foci, which served as preneoplastic markers, were measured in serial sections of liver by the method of quantitative stereology. Rats receiving oat lipids-supplemented diets had five- to sixfold higher levels of I-compounds in their liver DNA than those receiving control diets. Meanwhile, rats receiving diets containing oat lipids during promotion had significantly smaller numbers and reduced volume of altered hepatic foci compared with those fed the control diet containing corn oil. These observations support the hypothesis that some I-compounds, e.g., the oats- specific I-compounds, are novel DNA modifications related to nutrient metabolism. The diet containing oat lipids may have chemopreventive activities, as demonstrated in this model system.
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U2 - 10.1080/01635589909514746
DO - 10.1080/01635589909514746
M3 - Article
C2 - 10227042
AN - SCOPUS:0032967309
SN - 0163-5581
VL - 33
SP - 40
EP - 45
JO - Nutrition and cancer
JF - Nutrition and cancer
IS - 1
ER -