Role of Lipotropes in Mammary Carcinogenesis
Abstract
This study examined (1) the susceptibility of female rats previously exposed to lipotrope-modified diets to nitrosomethylurea (NMU)-induced mammary carcinogenesis; and (2) how lipotrope-modified diets modulate DNA methylation and gene expression in mammary tissues. Female rats (36 d of age) were assigned to one of following groups: control-synthetic diet (CSD), containing all required lipotropes; methyl-deficient diet (MOD), lacking all lipotropes; and methyl-additive diet (MAD), containing 1.5-fold the amount of each lipotrope as in CSD. Rats were injected with NMU after a 2-wk dietary treatment period, and 2 d after NMU administration all treatment groups were fed CSD for the remaining experimental period. Mammary tissues were collected from rats just prior to NMU administration. Dietary modification of lipotropes altered the DNA methylation pattern of ODC but not that of c-jun. The level of ornithine decarboxylase (ODC) mRNA was higher in mammary tissues from the MDD group than in that from the MAD group. DNA was significantly hypomethylated in mammary tissues of the MDD rats. These results suggest that dietary deficiency of lipotropes led to changes in DNA methylation and enhanced NMU-induced mammary carcinogenesis.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1996
- Accession Number
- ADB225308
Entities
People
- Chung S. Park
Organizations
- North Dakota State University