Navigation Links
Previously unseen switch regulates breast cancer response to estrogen
Date:5/8/2008

A tiny modification called methylation on estrogen receptors prolongs the life of these growth-driving molecules in breast cancer cells, according to research by scientists at Emory University's Winship Cancer Institute.

The results are published in the May 9, 2008 issue of the journal Molecular Cell.

Most breast cancers contain estrogen receptors, which enable them to grow in the presence of the hormone estrogen. Their presence can determine whether tumors will respond to the estrogen-blocking drug tamoxifen.

The finding will help researchers sort out how mutations change the estrogen receptor's function and allow some breast cancers to resist tamoxifen, says Paula Vertino, PhD, associate professor of radiation oncology at Emory University School of Medicine.

"The problem is that a significant fraction of estrogen receptor positive tumors don't respond to tamoxifen," Vertino says. "Development of new drugs that interfere with the methylation of the estrogen receptor may be an alternative way to treat those tumors."

Until recently, scientists thought methylation enzymes acted only on DNA molecules or on histones, proteins that bundle DNA into spool-like packages. Methylation enzymes add tags called methyl groups to other molecules, influencing their ability to turn genes on or off.

Vertino and her colleagues found that one of the modification enzymes, called SET7, methylates a flexible part of the estrogen receptor. When they created breast cancer cells with reduced levels of SET7, the estrogen receptor molecules lasted only half as long and were less effective in turning on genes.

Vertino's team showed that a mutation in the estrogen receptor found in more aggressive breast tumors interferes with methylation in cells. Also, the methylation appears in exactly the same spot where another protein called BRCA1 adds a different kind of regulatory marking, and may block BRCA1's restrictive effects on the estrogen receptor.

Women who inherit a mutation in the gene that encodes BRCA1 have up to an 80 percent lifetime risk of developing breast cancer, several times the risk of those who don't have it, according to the National Cancer Institute. BRCA1 mutations are estimated to account for about a third of all inherited breast cancers and roughly 2-3 percent of all breast cancers.

Scientists are beginning to look for drugs that could modulate methylation enzymes. Vertino says that methylation probably affects several other proteins similar to the estrogen receptor.

"I expect this will be just the tip of the iceberg," she says. "Methylation may be just as common as other protein modifications, and even more complicated."


'/>"/>

Contact: Vince Dollard
vdollar@emory.edu
404-778-4580
Emory University
Source:Eurekalert

Related medicine news :

1. Brain cells work differently than previously thought
2. Bristol-Myers Squibb Finalizes Settlement of Previously Disclosed Federal Investigation into Pricing, Sales and Marketing Practices
3. New transfusion rules restrict donations from previously pregnant women
4. Z Trim Holdings Reports Restatement of Previously Issued Financial Statements; Amends Bylaws
5. CDC Reports Prevalence of Worms Transmitted by Dogs and Cats to Humans is Higher Than Previously Understood
6. China Sky One Medical Completes Previously Announced Amendment to 2006 Form 10KSB
7. Symmetry Medical Provides Update of Previously Disclosed Accounting Review at Sheffield, UK Operating Unit
8. More functional DNA in genome than previously thought
9. The Ensign Group, Inc. Acquires Assets of Three Previously Leased Facilities
10. HealthSouth Announces Final Agreement on Previously Disclosed Settlement with Federal Government
11. China Sky One Medical Completes Previously Announced Amendments to Form 10QSB for the Second and Third Quarters of 2006
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/26/2016)... ... June 27, 2016 , ... Quality metrics are proliferating ... many ways they remain in the eye of the beholder, according to experts who ... of The American Journal of Managed Care. For the full issue, click here ...
(Date:6/26/2016)... ... June 26, 2016 , ... PawPaws brand pet supplements ... was developed to enhance the health of felines. The formula is all-natural and is ... herbs in the PawPaws Cat Kidney Support Supplement Soft Chews are Astragalus ...
(Date:6/25/2016)... D.C. (PRWEB) , ... June 25, 2016 , ... ... discuss health policy issues and applications at AcademyHealth’s Annual Research Meeting June 26-28, ... their work on several important health care topics including advance care planning, healthcare ...
(Date:6/25/2016)... ... 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX users can easily ... of Pixel Film Studios. , ProHand Cartoon’s package transforms over 1,300 hand-drawn pictures ... . Simply select a ProHand generator and drag it above media or text in ...
(Date:6/25/2016)... Oklahoma City, Oklahoma (PRWEB) , ... June 25, ... ... to helping both athletes and non-athletes recover from injury. Recently, he has implemented ... for the Oklahoma City area —Johnson is one of the first doctors to ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016   Bay ... Rehabilitation Network,s Dean Center for Tick Borne ... Medicine and Rehabilitation, MIT Hacking Medicine, University of ... Innovation, today announced the five finalists of ... Lyme disease.  More than 100 scientists, clinicians, researchers, ...
(Date:6/24/2016)... , June 24, 2016 ... the "Structural Electronics 2015-2025: Applications, Technologies, Forecasts" ... In-Mold Electronics, Smart Skin, Structural ... Structural electronics involves electronic and/or ... protective structures, replacing dumb structures such as vehicle ...
(Date:6/24/2016)... , June 24, 2016 Dehaier Medical Systems ... "Company"), which develops, markets and sells medical devices and ... , signed a strategic cooperation agreement with Hongyuan Supply ... Supply Chain") on June 20, 2016, to develop Dehaier,s ... strategic cooperation agreement, Dehaier will leverage Hongyuan Supply Chain,s ...
Breaking Medicine Technology: