The Role of Estrogen and Cancer


How does estrogen cause cancer? One American Cancer Society researcher is on a quest to find out.

Estrogen is one of the most important hormones in a woman’s body. It promotes secondary sex characteristics, accelerates metabolism, and increases bone formation. Unfortunately, estrogen also stimulates the growth of more than half of all breast cancer cases. Dr. Hua Shi of the State University of New York at Albany received a $687,000 Research Scholar Grant from the American Cancer Society to uncover how this hormone causes cancer in women.

Estrogen is mediated by human estrogen receptors (ERs), and these forms of breast cancer are treatable by ER antagonists. The biology and pharmacology of estrogen also rely on the co-regulators or cofactors that connects with the ERs. It is a challenge to grasp the mechanistic particulars of the estrogen-ER-cofactor relationship, and to use the molecular information to speed up the development of new cancer drugs.

One method to observe the biological mechanisms is to change particular genes or gene products and study the results. Sometimes this approach may offer a simulation of a diseased state, while sometimes it can propose a means of intervention to correct the fault. Both cases may be used to confirm drug targets.

Unfortunately, the tools available for researchers to search and agitate biological functions have severe limitations. A long-term goal of Dr. Shi’s laboratory is to create and utilize an approach of mechanism-based drug target validation in living cells and organisms by getting involved in molecular interactions that control biological processes.

The goal of this project is to produce unique reagents to vary the human estrogen receptor alpha (hER alpha) and to find drug target sites on this protein. Here ribonucleic acid (RNA) will be used as a material to create molecular partners for hER alpha.

These molecular partners will attach to specific sites on ER and occlude particular areas on the molecular surface. This will in turn inhibit ER activity. Current ER antagonists in clinical use bind to only one site on ER. This project will reveal and confirm more non-traditional sites as drug targets. The molecules found in Dr. Shi’s research can be used to create new drugs to treat breast cancer.

To learn more about American Cancer Society research grants, visit Research Central.