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:5/25/2016)... ... , ... Today Omega Institute, a leading destination for yoga education in New ... in the growing field of yoga therapy . Yoga therapy adapts the ... health issues—including injuries, illnesses, and temporary or chronic health conditions. , “Yoga therapy is ...
(Date:5/25/2016)... ... 25, 2016 , ... The Global Wellness Summit (GWS) today announced that its ... of Europe, a continent that pioneered the medical/wellness concept for the world. , Delegates ... medical wellness, including Henri Chenot, Founder of the Chenot Group, which operates wellness centers ...
(Date:5/25/2016)... (PRWEB) , ... May 25, 2016 , ... ... the results of its annual Medical and Prescription Drug survey , an ... , The survey, which was conducted in December 2015, indicates that employers ...
(Date:5/25/2016)... , ... May 25, 2016 , ... Laser Skin ... help turn back the hands of time of female aging. The Juliet™ ... Women with symptoms such as leakage, laxity, itchiness and pain have reported real ...
(Date:5/25/2016)... ND (PRWEB) , ... May 25, 2016 , ... Consumer ... easier. In early June 2016, Kashi®, a maker of whole grain cereals and other ... a Certified Transitional ingredient: hard red winter wheat processed by Hesco/Dakota Organic Products. ...
Breaking Medicine News(10 mins):
(Date:5/24/2016)... Dutch surgeons have launched a ground-breaking medical app to help ... on a global scale. Medical professionals from Europe ... and the US have already signed up for the app, which ... secure environment. Education  "Imagine a doctor for ... surgeon at Harvard to treat a bomb victim via live streaming ...
(Date:5/23/2016)... 23, 2016 Diplomat Pharmacy, Inc. (NYSE: DPLO) announced ... Internship programs. The hands-on learning experience is a 12-week ... paid Fellowship and Internship programs ... Fellows and interns are provided optional housing free of ... at the Riverfront Residence Hall to foster communication ...
(Date:5/23/2016)... 23, 2016 The World Health Organization (WHO) expanded ... to include adolescents aged 13 years, and above. Effective immediately, ... for adult and adolescent males in the 14 priority countries ... was the first male circumcision device to receive WHO Prequalification ... Eddy Horowitz said: " The expanded use ...
Breaking Medicine Technology:
Cached News: