Dietary fat promotes mammary tumorigenesis in MMTV/v-Ha-ras transgenic mice.
The purpose of this study was to investigate the influence of dietary fat on mammary tumorigenesis in MMTV/v-Ha-ras transgenic mice. Female MMTV/v-Ha-ras transgenics were fed diets providing 0, 5 or 25% of calories from corn oil (CO). The mammary tumor incidence was 7% (0% CO), 36% (5% CO) and 52% (25% CO). Ras mRNA levels were increased in mammary tumors in the 25% CO group. The ras transgene was hypomethylated in mammary tumors, but not in liver or nontransformed mammary tissue. Mammary tumors expressed apolipoprotein E mRNA. Alterations in gene structure and expression in transgenic mice may suggest mechanisms by which dietary fat promotes mammary tumors.
DeWille
J W
JW
Ohio State University, Department of Veterinary Pathobiology, Columbus 43210-1093.
Waddell
K
K
Steinmeyer
C
C
Farmer
S J
SJ
D000818:Animals; D001057:Apolipoproteins E / Q000032:analysis; D003314:Corn Oil / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000032:analysis; D004041:Dietary Fats / Q000494:pharmacology*; D005260:Female; D011905:Genes, ras; D015674:Mammary Neoplasms, Animal / Q000139:chemically induced* / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis
D001057:Apolipoproteins E; D004273:DNA, Neoplasm; D004041:Dietary Fats; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D003314:Corn Oil