Breast cancer is the second leading cause of cancer death among American women. Risk factors for breast cancer include obesity, alcohol consumption, and estrogen therapy. In the present studies, we determine the simultaneous effects of these three risk factors on wingless int (Wnt)-1 mammary tumor growth.
Ovariectomized female mice were fed diets to induce different body weights (calorie restricted, low fat, high fat), provided water or 20% alcohol, implanted with placebo or estrogen pellets and injected with Wnt-1 mouse mammary cancer cells.
Our results show that obesity promoted the growth of Wnt-1 tumors and induced fatty liver. Tumors tended to be larger in alcohol-consuming mice and alcohol exacerbated fatty liver in obese mice. Estrogen treatment promoted weight loss in obese mice, which was associated with the suppression of tumor growth and fatty liver.
In summary, we show that estrogen protects against obesity, which is associated with the inhibition of fatty liver and tumor growth.
From the 1Department of Nutritional Sciences, School of Human Ecology, College of Natural Sciences, The University of Texas at Austin, Austin, TX; and 2Department of Molecular Biology, Princeton University, Princeton, NJ.
Received September 6, 2011; revised and accepted October 13, 2011.
V.B.H. and J.H. contributed equally to this work.
Funding/support: This study was funded by grants ACS RSG CNE-113703 (NPN), NCI 1K22CA127519-01A1 (NPN), NIEHS National Institutes of Health ES09145, and National Institute of Environmental Health Sciences Center ES007784.
Financial disclosure/conflicts of interest: None reported.
Address correspondence to: Nomelı´ P. Nu´n˜ez, PhD, Department of Nutritional Sciences, School of Human Ecology, College of Natural Sciences, The University of Texas at Austin, 1 University Station A2703, PAI 5.14, Austin, TX 78712. E-mail: email@example.com