Grant helps biologists to study estrogen's role in breast cancer

By Roger Segelken

A four-year, $650,000 Research Scholar Grant from the American Cancer Society (ACS) will help Cornell biologist W. Lee Kraus, assistant professor of molecular biology and genetics, and his laboratory learn more about how the hormone estrogen regulates the growth of cells in the human body -- including cells that develop into breast cancers.

W. Lee Kraus, assistant professor of molecular biology, and graduate student Mi Young Kim examine human breast cancer cells in Kraus' Biotechnology Building lab, Oct. 31. Charles Harrington/University Photography

Kraus credits a graduate student in his laboratory, Mi Young Kim, with the discovery of two enzymes that apparently act on estrogen receptors, the hormone-binding proteins that bind estrogens inside cells. The researchers now hope to learn how these estrogen receptor-modifying enzymes, called an acetylase and a deacetylase, alternately add or remove acetyl groups at the receptor and what effect these modifications have on the activity of the receptors in normal and cancerous human mammary cells.

Certain drugs, such as Tamoxifen, are routinely prescribed to treat or prevent estrogen-related cancers because the drugs block the cellular growth-promoting actions of estrogen at the receptor level. But the molecular details of how natural receptor modifications, such as the addition of acetyl groups, regulate the activity of the receptors in response to estrogens are not clear to medical science, and Kraus expects his ACS-sponsored studies will help explain more clearly the details of the estrogen signaling pathway in normal and diseased tissues.

"Ultimately, we would like to use this information to find better ways to target estrogen receptors for more effective diagnostic, preventative and therapeutic options for breast cancer patients," he said.

A member of the Cornell faculty since 1999, Kraus also is an adjunct assistant professor of pharmacology at Weill Cornell Medical College. He traces his interest in estrogen signaling back nearly 15 years to when he was a Cornell undergraduate (class of '89) majoring in animal physiology and conducting research into gene regulation by steroid hormones in the laboratory of W. Bruce Currie, professor of animal science. Kraus went on to earn M.S. and Ph.D. degrees in physiology at the University of Illinois at Urbana-Champaign and did his postdoctoral research at the University of California-San Diego. Other sponsors of his hormone-related research at Cornell include the National Institutes of Health (a five-year, $1 million grant), the Burroughs Wellcome Fund (a 1998 career award in biomedical sciences) and the Susan G. Komen Breast Cancer Foundation (a fellowship to Edwin Cheung, a senior postdoctoral researcher in Kraus' lab).

The American Cancer Society is a nationwide, community-based, voluntary health organization dedicated to eliminating cancer as a major health problem through research, education, advocacy and service. The society spends approximately $130 million on cancer research each year, including $34.2 million in New York state and, as of January 2003, it will have more than $1 million in research grants in action at Cornell's Ithaca campus.