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:
*Name:
*Comment:
*Email:


(Date:6/23/2017)... , ... June 23, 2017 , ... Everybody has their ... while others prefer to read it, and some people don't like it at all. ... Here's what they found: , Erotic literature can give readers a taste of their ...
(Date:6/23/2017)... ... June 23, 2017 , ... 21 Middle East and South Asia Leaders Selected ... from government, business and civil society in 11 countries across the Middle East and ... in a transformative exchange of knowledge and ideas with the leading minds in their ...
(Date:6/23/2017)... ... 23, 2017 , ... Ulster University, Magee Campus in Northern Ireland is hosting ... pm to present to graduate students exciting new and innovative hope research based on ... by The Health Improvement Service of the Western Health & Social Care Trust (WHSCT) ...
(Date:6/23/2017)... ... June 23, 2017 , ... Moore Insurance, ... area with access to asset protection and financial planning services, is teaming up ... improving the lives of children with cancer and other chronic diseases. , The ...
(Date:6/22/2017)... ... June 22, 2017 , ... ... from the American Heart Association (AHA) to launch a Rheumatic Heart Disease Center, ... prevention and diagnosis of rheumatic heart disease (RHD) in high-risk, financially disadvantaged countries ...
Breaking Medicine News(10 mins):
(Date:6/16/2017)... , June 16, 2017  Exactly 50 years ago ... off what later became known as the San Francisco "Summer ... ) is unveiling two radical innovations in strategic market research ... This announcement marks the beginning of Northern Light,s "Summer of ... ...
(Date:6/12/2017)... , June 12, 2017 Kineta, Inc., a biotechnology ... Kineta Vice President of R&D and Head of ... Pandemic Preparedness for the Northwest and Beyond meeting ... on June 14, 2017 from 8:30-10:30 AM PDT at the ... Dr. Bedard will be joined by other ...
(Date:6/8/2017)... MAITLAND, Fla. , June 8, 2017  Less ... ransomware attack that hit more than 200,000 companies, including hospital ... is being heralded as one of the largest online ... technology in the healthcare market, it is imperative that ... can protect their data from this — and many ...
Breaking Medicine Technology:
Cached News: