Margot P. Cleary, PhD

2007-2008 BCRF Project:
Dr. Cleary's recent studies indicate that proteins made in fat tissue have important impact on either prevention or enhancement of breast cancer cell growth dependent upon specific characteristics of the cells. In particular, estrogen receptor status is important. When the protein leptin that is present in the blood in relation to body fat levels is added to human breast cancer cells, there is a greater impact on cell proliferation in estrogen receptor positive breast cancer cells compared to the identical cell line without the estrogen receptor. Additional experiments indicate that a second fat tissue protein, adiponectin, that is inversely related to fat mass, protects breast cancer cells from proliferating, and this effect is greater in cells that have estrogen receptors. In the coming year, adiponectin levels relative to the amount of leptin will be evaluated to determine optimal amounts to protect breast cancer cells from proliferating and forming tumors.

Mid-Year Progress Report:
Obesity is a risk factor for postmenopausal breast cancer. Dr. Cleary’s group has found that leptin, a protein which circulates in the blood in proportion to body fat stores, is a growth factor for breast cancer cells. Now they are studying another protein produced in fat tissue, adiponectin (Arcp30), which circulates at decreased concentrations as body fat increases. The researchers found that adiponectin, at levels comparable to those in normal weight women, reduces breast cancer cell proliferation. Furthermore, they found that the ratio of serum adiponectin:leptin plays an important role in breast cancer cell proliferation particularly when the estrogen receptor is present. Continued study will determine the role of the adiponectin:leptin ratio in cell death and in tumor development in preclinical models. These studies provide new insights into how body fat and proteins produced in fat tissue affect breast cancer development.

Bio:
Margot Cleary received her B. A. degree in Chemistry from Regis College, Weston, MA. She then undertook graduate education at the Institute of Human Nutrition, Columbia University, NYC, NY where she was awarded M.S., M.Phil. and Ph.D. degrees. She followed this with two-years of postdoctoral training at the Institute of Human Nutrition at Columbia before accepting a faculty position in the Department of Nutrition and Food Science at Drexel University, Philadelphia, PA. Presently, Dr. Cleary is a Professor at the Hormel Institute, University of Minnesota in Austin, MN and also a Visiting Scientist at Mayo Clinic, Rochester, MN.