Dr. Louie is studying how the heavy metal cadmium — an environmental contaminant that enters the body through consumption of contaminated food, water or inhalation of cigarette smoke — contributes to the development of breast cancer. Her preliminary findings not only show that cadmium promotes breast cancer cell growth, but her lab may have also identified a potential pathway for its action.
Breast cancer results from the abnormal growth of cells in the mammary gland. The development of the mammary gland is regulated by estrogen, a hormone that binds to the estrogen receptor (ER). Most breast cancer cases initially develop as hormone-dependent cancer, in which growth and progression of the disease correlates with estrogen levels. Doctors have been battling this cancer with drugs known as anti-estrogens, which are designed to block the receptor. Although such treatments have proven successful, the cancer can later develop into a more aggressive, hormone- independent tumor.
“The mechanism of how hormone independence develops is not clear, and my current research is focused on understanding the mechanism of how hormone-refractory breast cancer develops,” says Louie. “One potential mechanism may involve endocrine disruptors including heavy metals such as cadmium.”
Several studies conducted by researchers elsewhere back up the theory that cadmium may enhance the ER function and promote the development of breast cancer. Louie’s preliminary findings show, however, that cadmium also may activate another signaling mechanism and promote breast cancer.
Louie’s challenge now is to characterize the role of cadmium in breast cancer cell growth and create a molecular ‘map’ that shows cadmium’s role in regulating the expression of the classical ER and the non-classical ER target genes.
“Results from this study will not only provide a better understanding of how environmental contaminants such as cadmium can promote breast cancer, but also offer new insights to how the estrogen receptor can regulate both classical and non-classical ER target gene expression,” says Louie.
The results also would have significant clinical contributions, including screening for heavy metal toxicities, identifying heavy metal-associated breast cancer cases, and designing more effective therapeutics for breast cancer.
Louie received her Ph.D in biochemistry and molecular biology from UC Davis, where she continued with postdoctoral research on cancer biology before joining Dominican’s Department of Natural Sciences and Mathematics in 2005. Her research has been published in several peer review journals, including Molecular and Cellular Biology and The Proceedings of the National Academy of Sciences.
Posted May 11, 2007