Featured Research

from universities, journals, and other organizations

Resistance to anti-estrogen therapy in breast cancer due to natural cell response

Date:
April 4, 2011
Source:
Georgetown University Medical Center
Summary:
Most breast cancers are fueled by estrogen, and anti-estrogenic agents often work for a time to control the cancers. But many of these cancers become resistant to the drugs for reasons that are not understood, leaving patients with limited treatment options. Now researchers say that this resistance appears to be due to a natural stress response in cells, and that the biochemical molecules involved in this response might prove to be a new drug target.

Most breast cancers are fueled by estrogen, and anti-estrogenic agents often work for a time to control the cancers. But many of these cancers become resistant to the drugs for reasons that are not understood, leaving patients with limited treatment options.

Now researchers at the Georgetown Lombardi Comprehensive Cancer Center, a part of Georgetown University Medical Center (GUMC), say that this resistance appears to be due to a natural stress response in cells, and that the biochemical molecules involved in this response might prove to be a new drug target. They reported their findings at the American Association for Cancer Research (AACR) 102nd Annual Meeting 2011 in Orlando, Florida.

They found that breast cancer cells protect themselves against two anti-estrogen drugs (Tamoxifen and Faslodex) by hijacking and switching on a biological process inside the cells that is normally used when proteins are produced that don't have the right shape.

It had not been known, before this study, that this program -- the "unfolded protein response" or UPR -- could be triggered when breast cancer cells are "attacked" by anti-estrogen drugs, says the study's lead investigator, Ayesha Shajahan, Ph.D., an oncology researcher instructor and researcher in the laboratory of Robert Clarke, Ph.D., D.Sc., Dean for Research at GUMC. Clarke will be presenting the results at AACR.

If a UPR is activated, a cell can do one of two things, Shajahan says: it can turn on a pro-survival pathway or it can turn on a process that ultimately destroys the cell. The cells they studied all chose to "man the forts" to survive. They hunker down and wait out the attack, a tactic that allows the cell to resist anti-cancer treatment.

"We found that anti-estrogen resistant cancer cells are much more likely to turn on the pro-survival pathway than are cells that are sensitive to estrogen," says Shajahan.

They also found that anti-estrogen resistant breast cancer cells over-express the X-Box Binding Protein (XBP1), which turns on UPR signaling, and that specific resistance to Faslodex (Fulvestrant) occurs because of increased levels of over-expression of a XBP1 subtype, XBP1(s).

The study was funded by the Department of Defense Idea Award BC073977 to Clarke. The authors report having no personal financial interests related to the study.


Story Source:

The above story is based on materials provided by Georgetown University Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Georgetown University Medical Center. "Resistance to anti-estrogen therapy in breast cancer due to natural cell response." ScienceDaily. ScienceDaily, 4 April 2011. <www.sciencedaily.com/releases/2011/04/110404131456.htm>.
Georgetown University Medical Center. (2011, April 4). Resistance to anti-estrogen therapy in breast cancer due to natural cell response. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2011/04/110404131456.htm
Georgetown University Medical Center. "Resistance to anti-estrogen therapy in breast cancer due to natural cell response." ScienceDaily. www.sciencedaily.com/releases/2011/04/110404131456.htm (accessed April 18, 2014).

Share This



More Health & Medicine News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) 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