Proliferative endocrine effects of adipose tissue from obese animals on MCF7 cells are ameliorated by resveratrol supplementation

Obesity is clearly associated with an increased risk of breast cancer in postmenopausal women. The purpose was to determine if obesity alters the adipocyte adipokine secretion profile, thereby altering the adipose-dependent paracrine/endocrine growth microenvironment surrounding breast cancer cells (MCF7). Additionally, we determined whether resveratrol (RSV) supplementation can counteract any obesity-dependent effects on breast cancer tumor growth microenvironment. Obese ZDF rats received standard chow diet or diet supplemented with 200 mg/kg body weight RSV. Chow-fed Zucker rats served as lean controls. After 6 weeks, conditioned media (CM) prepared from inguinal subcutaneous adipose tissue (scAT) was added to MCF7 cells for 24 hrs. Experiments were also conducted using purified isolated adipocytes to determine whether any endocrine effects could be attributed specifically to the adipocyte component of adipose tissue. scAT from ZDF rats promoted cell cycle entry in MCF7 cells which was counteracted by RSV supplementation. RSV-CM had a higher ratio of ADIPO:LEP compared to ZDF-CM. This altered composition of the CM led to increased levels of pAMPK(T172), p27, p27(T198) and AdipoR1 while decreasing pAkt(T308) in MCF7 cells grown in RSV-CM compared to ZDF-CM. RSV-CM increased number of cells in G0/G1 and decreased cells in S-phase compared to ZDF-CM. Co-culture experiments revealed that these obesity-dependent effects were driven by the adipocyte component of the adipose tissue. Obesity decreased the ratio of adiponectin:leptin secreted by adipocytes, altering the adipose-dependent growth microenvironment resulting in increased breast cancer cell proliferation. Supplementation with RSV reversed these adipose-dependent effects suggesting a potential for RSV as a nutritional supplementation to improve breast cancer treatment in obese patients.