title: Estrogen deprivation and excess energy supply accelerate 7,12-dimethylbenz(a)anthracene-induced mammary tumor growth in C3H/HeN mice.
abstract: OBJECTIVE
  Obesity is a risk factor of breast cancer in postmenopausal women. Estrogen deprivation has been suggested to cause alteration of lipid metabolism thereby creating a cellular microenvironment favoring tumor growth. The aim of this study is to investigate the effects of estrogen depletion in combination with excess energy supply on breast tumor development.
  
  
  METHODS
  Ovariectomized (OVX) or sham-operated C3H/HeN mice at 4 wks were provided with either a normal diet or a high-fat diet (HD) for 16 weeks. Breast tumors were induced by administration of 7,12-dimethylbenz(a)anthracene once a week for six consecutive weeks.
  
  
  RESULTS
  Study results showed higher serum concentrations of free fatty acids and insulin in the OVX+HD group compared to other groups. The average tumor volume was significantly larger in OVX+HD animals than in other groups. Expressions of mammary tumor insulin receptor and mammalian target of rapamycin proteins as well as the ratio of pAKT/AKT were significantly increased, while pAMPK/AMPK was decreased in OVX+HD animals compared to the sham-operated groups. Higher relative expression of liver fatty acid synthase mRNA was observed in OVX+HD mice compared with other groups.
  
  
  CONCLUSIONS
  These results suggest that excess energy supply affects the accelerated mammary tumor growth in estrogen deprived mice.
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, 100 Chungpa-ro 47-gil, Yongsan-gu, Seoul, 140-742, Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, 100 Chungpa-ro 47-gil, Yongsan-gu, Seoul, 140-742, Korea.
authors.forename: Yoon Hee
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Food Science and Nutrition, College of Natural Sciences, Hallym University, 39 Hallymdaehak-gil, Chuncheon, 200-702, Korea.
authors.forename: Jung Han Yoon
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, 100 Chungpa-ro 47-gil, Yongsan-gu, Seoul, 140-742, Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Sung
keywords: Breast cancer; estrogen; obesity; postmenopause