Featured Research

from universities, journals, and other organizations

Enzyme may drive breast cancer growth

Date:
May 20, 2011
Source:
University of Illinois at Chicago
Summary:
A recently discovered enzyme drives the production of a potent form of estrogen in human breast cancer tissue, according to new research.

A recently discovered enzyme drives the production of a potent form of estrogen in human breast cancer tissue, researchers from the University of Illinois at Chicago College of Medicine have found.

The extra-strength estrogen, called estradiol, then drives the production of even more enzyme, in what may be a lethal feed-forward mechanism. Estradiol has been implicated in exacerbating tumor growth in breast cancer.

The research is published in the May issue of the journal Molecular Endocrinology.

Scientists had observed the increased production of an unknown protein in ovarian tissue in response to estrogen. UIC researchers under the direction of Geula Gibori, UIC professor of physiology and biophysics, then purified the protein and cloned its gene. Several laboratories established that it is an enzyme that converts a weak estrogen, estrone, to the much more potent estradiol.

The UIC researchers then examined the production of the enzyme in a line of breast cancer cells known to respond to estrogen levels.

"Estradiol up-regulates the very enzyme that produces estradiol, creating a positive cycle where this potent form of estrogen is being produced over and over again, sustaining its own production," said Aurora Shehu, UIC postdoctoral research associate in physiology and biophysics and first author of the study.

In human breast tissue, the researchers found a "dramatic" up-regulation in the cancerous cells but not in the surrounding benign tissue, said Gibori, who is principal investigator on the study. The surrounding tissue, however, is a rich source of the estrone that the enzyme needs to produce more estradiol, she said.

The researchers were able to show how estradiol turns on the gene that produces the enzyme, and that this activation also required at least one other known regulatory factor.

They found that tamoxifen, a drug widely used to inhibit breast cancer growth, prevents estradiol's stimulation of the enzyme and thus may shut down local production of estradiol in breast cancer cells.

"Breast cancer tumors with this enzyme are likely to be a much more aggressive and potentially deadly type of cancer," Gibori said. "Identifying this enzyme and how its expression is turned on gives medical researchers potential targets for disrupting the lethal production of estradiol in breast cancers."

The enzyme is a promising therapeutic target because blocking it may halt production only of the dangerous estradiol, which would reduce the side effects seen with other drugs that inhibit production of many estrogen-related compounds, Gibori said.

This study was supported by grants from the National Institutes of Health. Y. Sangeeta Devi, Kristin Luther, Julia Halpern, Jamie Le, Jifang Mao, Rachel Duan and Jonna Frasor from UIC and Constance Albarracin of the University of Texas, Houston, also contributed to the study.


Story Source:

The above story is based on materials provided by University of Illinois at Chicago. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. Shehu, C. Albarracin, Y. S. Devi, K. Luther, J. Halperin, J. Le, J. Mao, R. W. Duan, J. Frasor, G. Gibori. The Stimulation of HSD17B7 Expression by Estradiol Provides a Powerful Feed-Forward Mechanism for Estradiol Biosynthesis in Breast Cancer Cells. Molecular Endocrinology, 2011; 25 (5): 754 DOI: 10.1210/me.2010-0261

Cite This Page:

University of Illinois at Chicago. "Enzyme may drive breast cancer growth." ScienceDaily. ScienceDaily, 20 May 2011. <www.sciencedaily.com/releases/2011/05/110518161711.htm>.
University of Illinois at Chicago. (2011, May 20). Enzyme may drive breast cancer growth. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2011/05/110518161711.htm
University of Illinois at Chicago. "Enzyme may drive breast cancer growth." ScienceDaily. www.sciencedaily.com/releases/2011/05/110518161711.htm (accessed September 17, 2014).

Share This



More Health & Medicine News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Obama Orders Military Response to Ebola

Obama Orders Military Response to Ebola

AP (Sep. 16, 2014) Calling the Ebola outbreak in West Africa a potential threat to global security, President Barack Obama is ordering 3,000 U.S. military personnel to the stricken region amid worries that the outbreak is spiraling out of control. (Sept. 16) Video provided by AP
Powered by NewsLook.com
UN: 20,000 Could Be Infected With Ebola by Year End

UN: 20,000 Could Be Infected With Ebola by Year End

AFP (Sep. 16, 2014) Nearly $1.0 billion dollars is needed to fight the Ebola outbreak raging in west Africa, the United Nations say, warning that 20,000 could be infected by year end. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Obama: Ebola Outbreak Threat to Global Security

Obama: Ebola Outbreak Threat to Global Security

AP (Sep. 16, 2014) President Obama is ordering U.S. military personnel to West Africa to deal with the Ebola outbreak, which is he calls a potential threat to global security. (Sept. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins