NMSU branding

New Mexico State University

New Mexico State University

News Center

NMSU researcher aids in discovery of new estrogen receptor

The discovery of a new intracellular estrogen receptor by a team of researchers from New Mexico State University and the University of New Mexico has significant implications for the diagnosis and treatment of diseases such as breast cancer.

"Estrogen is a key mammalian hormone involved in normal cells as well as in diseases such as cancer," NMSU chemistry professor Jeffrey Arterburn said. An estrogen receptor is a protein inside the cell that binds estrogen which then activates cell growth. This is a key issue in cancer cells.

"In breast cancer, for example, one of the first things we want to know is whether the tumor cells are estrogen receptor positive or negative," Arterburn said. "That dictates the type of treatment the individual will receive."

If the cells contain estrogen receptors, doctors will treat them with drugs such as tamoxifen. If not, another type of treatment will be recommended.

But those treatment decisions have been made based on the idea that there were two known receptors: ER alpha discovered about 40 years ago, and ER beta identified about 10 years ago.

The discovery by Arterburn and colleagues from the University of New Mexico that GPR30, a protein molecule found inside cells, also is an estrogen receptor means the whole design of that treatment must be re-evaluated, said team member Eric Prossnitz, a cell biologist with UNM and the corresponding author for their research paper.

Their report, "A Transmembrane Intracellular Estrogen Receptor Mediates Rapid Cell Signaling," is presented in Science Magazine's Feb. 10 edition. The other team members are Chetana M. Revankar, Daniel F. Cimino and Larry A. Sklar, all of UNM.

The activity of GPR30 was discovered after Arterburn, a synthetic chemist, developed a fluorescent version of estradiol, the most important estrogen hormone. That fluorescence allowed the scientists to follow the estradiol and watch where it went and how it interacted in an actual cell.

"We have to think of this in the broader context," Arterburn said. "The fluorescent molecule is useful for studying cell culture in a laboratory. It allows us to see what happens within the cells themselves. But to get images from someone's body, we want to have estradiol containing a nuclear medicine isotope that can be injected. That way, it can be detected right in the clinic whether or not a person has an estrogen-receptor associated cancer."

The team also is trying to study what other roles GPR30 plays in normal physiology and disease tissues.

"We have to look hard since it could be doing things in the cells that scientists are attributing to something else," Arterburn said. "This research represents how important it is for scientists to be able to work together despite different backgrounds."

In addition to treatment for cancer, the discovery by the NMSU/UNM team has implications for the treatment of bone disorders such as osteoporosis.