HOME >> MEDICINE >> NEWS
Duke/Novalon researchers identify potential mechanism behind tamoxifen resistance in breast cancers

DURHAM, N.C. -- Scientists have identified a likely reason why the breast cancer drug tamoxifen stops working in women who use it for more than five years. They say their discovery could lead to new drugs that either work better than tamoxifen or prevent a woman's resistance to the drug.

The researchers, from Duke University Medical Center and Novalon Pharmaceutical Corp., reported in the July 30 issue of Science that tamoxifen initiates a cascade of changes inside the breast cell that are far different from the effects of estrogen or other compounds that rouse the estrogen receptor into action.

Tamoxifen's desired action is to block the effects of estrogen, a hormone involved in the growth of half of all breast cancers. It works by binding to the estrogen receptor and blocking estrogen from docking to it. Hence, tamoxifen has been called an "anti-estrogen." Later, however, tamoxifen begins to lose its effectiveness, and researchers have long wondered why.

Now, they have learned that instead of acting like either an estrogen or an anti-estrogen, tamoxifen has its own distinct properties that drive the cell's estrogen receptor into a different shape than estrogen or other estrogen "mimics" would. The shape the receptor takes determines how the cell will behave and what activity it will generate.

In the case of tamoxifen, the researchers found that it causes the estrogen receptor in breast cells to form an additional and unique "pocket" or surface -- a place where other proteins inside the cell can bind to or dock themselves. While these proteins have yet to be identified, the researchers say their action of binding to this new pocket on the receptor is what changes the cell's response to tamoxifen. For reasons unknown, the cells then begin to see tamoxifen as an estrogen instead of an anti-estrogen, and hence the cancer once again proliferates.

"The implications of our discovering this new pocket fo
'"/>

Contact: Rebecca A. Levine
Levin005@mc.duke.edu
919-684-4148
Duke University Medical Center
30-Jul-1999


Page: 1 2 3 4

Related medicine news :

1. Indiana University researchers closer to helping hearing-impaired using stem cells
2. Protein that helps skin cancer spread identified by Stanford researchers
3. US life expectancy about to decline, researchers say
4. Gene for age-related macular degeneration discovered by Yale researchers
5. Dartmouth researchers find where musical memories are stored in the brain
6. Columbia researchers receive $3 million to combat genetic killer of infants & toddlers
7. US cancer researchers launch first American-Israeli cancer conference
8. USC dental researchers develop first test for predicting cavities in children
9. Young blood revives aging muscles, Stanford researchers find
10. Uric acid may help reduce effects of spinal cord injury, Jefferson researchers find
11. Age should not be a factor in determining heart transplantation eligibility, researchers say

Post Your Comments:
(Date:7/7/2015)... ... July 07, 2015 , ... The Immune Deficiency Foundation (IDF) ... community using its IDF ePHR, an electronic personal health record powered by Get ... easily track their health information, including symptoms, diagnoses, medications, infusions and other critical ...
(Date:7/7/2015)... ... 07, 2015 , ... Parents and guardians of teenagers or young adults will ... holistic treatment center for drug and alcohol abuse located in Southwest Michigan. A recently ... shown a significant increase in the “club drug” use among high school seniors. The ...
(Date:7/7/2015)... ... July 07, 2015 , ... ... of telemedicine programs in communities throughout Georgia, announces the launch of the first ... rural communities of Hancock County, GA. The new program will not only provide ...
(Date:7/7/2015)... NH (PRWEB) , ... July ... ... integrated, full-service public relations, marketing, and creative design firm, today announced that ... regional public relations and social media campaign, content strategy, and marketing launch ...
(Date:7/7/2015)... Horsham, PA (PRWEB) , ... July 07, 2015 ... ... seasoned financial executive Ellen Purdy as the company’s new Chief Financial Officer, effective ... financial and leadership experience in companies ranging from a multi-billion dollar, global chemical ...
Breaking Medicine News(10 mins):Health News:Get Real Health Launches New Mobile App for Immune Deficiency Foundation Patient Community 2Health News:Get Real Health Launches New Mobile App for Immune Deficiency Foundation Patient Community 3Health News:A Forever Recovery Releases New Information on “Club Drugs” and Tips for Parents of Teens and Young Adults 2Health News:Georgia Partnership for TeleHealth prepares to Launch First Ambulance Telemedicine Solution in Georgia 2Health News:TimberNook Selects Calypso Communications for PR, Social Media and Content Strategy 2Health News:Office Practicum Announces new CFO 2
(Date:7/7/2015)... SHENZHEN, China , July 7, 2015 /PRNewswire/ -- ... ), a leading developer, manufacturer and marketer of ... to acquire the remaining stake in Wuhan Dragonbio ... million. Dragonbio is a domestic ... joint and other surgical products. Prior to today,s ...
(Date:7/7/2015)... 2015 EnteroMedics Inc. (NASDAQ: ETRM ), ... technology to treat obesity, metabolic diseases, and other gastrointestinal ... offering of 32,000,000 units. Each unit consists of one share ... purchase one share of common stock at a purchase ... units in the offering would result in them beneficially ...
(Date:7/7/2015)... July 7, 2015 Oasmia ... of drugs within human and veterinary oncology, today ... in the United States , ... leading companion animal therapeutic.      (Logo: ... ) , Paccal Vet-CA1 was ...
Breaking Medicine Technology:Mindray Medical to Acquire the Remaining Stake in Wuhan Dragonbio 2Mindray Medical to Acquire the Remaining Stake in Wuhan Dragonbio 3Mindray Medical to Acquire the Remaining Stake in Wuhan Dragonbio 4EnteroMedics Inc. Announces Pricing of $16.0 Million Public Offering of Common Stock and Warrants 2EnteroMedics Inc. Announces Pricing of $16.0 Million Public Offering of Common Stock and Warrants 3Oasmia Pharmaceutical Launches US Brand and Sales Platform 2
Cached News: