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:10/13/2017)... ... October 13, 2017 , ... While it’s often important ... problem. Fortunately, an inventor from Austin, Texas, has identified a solution. , She developed ... darkness or restricted lighting. As such, it eliminates the need to turn on a ...
(Date:10/13/2017)... ... October 13, 2017 , ... ... alumni Hannah Randall, PharmD ‘17, and Jennifer Huggins, PharmD ’17, along with ... for the primary prevention of cardiovascular diseases during the 15th Annual Women’s ...
(Date:10/13/2017)... ... October 13, 2017 , ... The Visiting Nurse Association (VNA) ... a collection of specialty vendors and unique items from across the nation, this holiday-themed ... and wellness services offered by the VNA. The boutique will be open Saturday, ...
(Date:10/13/2017)... ... October 13, 2017 , ... ... viewers the lowdown on sciatica in a new episode of "Success Files," which ... current events and innovation and investigates each subject in-depth with passion and integrity. ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... ... advisory services for healthcare compliance program management, will showcase a range of technology ... Association for Assisted Living (NCAL) Convention and Expo to be held October 14–18, ...
Breaking Medicine News(10 mins):
(Date:9/12/2017)... and NEW YORK , Sept. 12, 2017   ... for global supply chains, has published the first annual edition of its ... of more than 20,400 companies evaluated by EcoVadis, based on Scorecard Ratings ... 2016. ... CSR Risk & Performance Index ...
(Date:9/12/2017)... Sept. 12, 2017  ValGenesis Inc., the global ... is pleased to announce the appointment of Dr. ... its Board of Directors and Chairman of Advisory ... life science companies to manage their entire validation ... paper in this process. Furthermore, ValGenesis VLMS enables ...
(Date:9/9/2017)... Sept. 8, 2017 Dealmed Medical Supplies, ... of medical equipment, supplies, drugs, vaccines, and specialty medical ... into an agreement to acquire Vantage Medical Supplies, a ... Holtsville, New York . ... new and emerging medical practices, will operate under the ...
Breaking Medicine Technology:
Cached News: