Navigation Links
Tamoxifen-resistant breast cancer reversed when drug paired with anti-malaria agent
Date:6/12/2014

WASHINGTON The inexpensive anti-malarial drug hydroxychloroquine (HCQ) reverses resistance to tamoxifen, a widely used breast cancer drug, in mice.

In the June 15 issue of Clinical Cancer Research, investigators from Georgetown Lombardi Comprehensive Cancer Center say adding HCQ to tamoxifen could provide a new treatment option for some women with advanced, postmenopausal estrogen receptor-positive (ER+) breast cancer. The ER+ subtype accounts for an estimated 70 percent of all breast cancers. While many of these women are treated with tamoxifen, which blocks estrogen from fueling the tumor, 50 percent of these cancers will either not respond or will become resistant to tamoxifen over time.

"Tamoxifen resistance when treating breast cancer is a big issue in the clinic, and we believe our findings provide a very promising fix to the problem," says the study's senior investigator, Robert Clarke, PhD, DSc, dean for research at Georgetown University Medical center, and co-director of the breast cancer program at Georgetown Lombardi.

Clarke adds that both drugs are inexpensive, on the market and have a well-defined safety profile.

HCQ was developed to treat malaria, but has since been repurposed as therapy for rheumatoid arthritis and lupus. The study is the first to test HCQ's ability to restore breast cancer cell sensitivity to tamoxifen or to a different anti-estrogen drug known as faslodex.

The research team, led by first author Katherine Cook, PhD, a postdoctoral research fellow in the tumor biology department at Georgetown Lombardi, purposely set out to test HCQ in mice with either tamoxifen or faslodex-resistant human breast cancer cells.

Previous research led by Clarke and Cook found that tamoxifen resistance occurs because a pro-survival pathway is switched on in breast cancer cells. HCQ functions by turning off that very same molecular pathway, Cook says.

The researchers found that the combination of tamoxifen and HCQ is more effective than faslodex and HCQ due to activities within the tumor's microenvironment. "Faslodex and tamoxifen, while both effective as antiestrogen therapies, have different effects on the immune system thus making the combination of faslodex and HCQ less effective," says Cook.

"Many people have been trying combinations of drugs to restore the ability of tamoxifen to fight breast cancer. We believe this pairing is very worthy of additional research, as well as clinical study," she says.


'/>"/>

Contact: Karen Teber
km463@georgetown.edu
Georgetown University Medical Center
Source:Eurekalert

Related medicine news :

1. New finding gives clues for overcoming tamoxifen-resistant breast cancer
2. Eliminating the good cholesterol receptor may fight breast cancer
3. Veggies Like Broccoli, Cabbage May Help Fight Breast Cancer: Study
4. Researchers develop a new cell and animal model of inflammatory breast cancer
5. Scientists uncover multiple faces of deadly breast cancer
6. Depo-Provera Birth Control Might Raise Breast Cancer Risk
7. Routine mammograms may result in significant overdiagnosis of invasive breast cancer
8. Mayo Clinic launches whole genome breast cancer study
9. Breast cancer patients suffer treatment-related side effects long after completing care
10. Teen Drinking May Boost Odds of Precancerous Breast Changes
11. Stress contributes to cognitive declines in women with breast cancer, researcher says
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/14/2017)... Petersburg, Florida (PRWEB) , ... January 14, 2017 , ... ... Emoji Scale. , The Emoji Scale is now available on Apple as a ... give emoji ratings simply by choosing one of the ten color coded values on ...
(Date:1/13/2017)... (PRWEB) , ... January 13, 2017 , ... KOAMTAC ... companions, will be showcasing the next generation companion scanner and data collector at the ... new KDC270 has been created as an answer to the market’s need for more ...
(Date:1/13/2017)... ... January 13, 2017 , ... "We wanted to create a design for orthodontic ... two inventors from Virginia Beach, Va. , They created a prototype for the patent-pending ... accessories allow braces to be customized to suit personal tastes. They can be used ...
(Date:1/13/2017)... ... 13, 2017 , ... As the nation watches this month’s transition to a ... schools of education across the country is urging a fundamental reconsideration of the problems ... today, 175 deans sounded the alarm: “Our children suffer when we deny that educational ...
(Date:1/13/2017)... ... January 13, 2017 , ... Dr. Les Latner, owner ... a fundraising campaign for the American Academy of Cosmetic Dentistry Charitable Foundation (AACDCF) ... in rebuilding the smiles and lives of adults who have suffered dental injuries ...
Breaking Medicine News(10 mins):
(Date:1/13/2017)... , January 13, 2017 ... "Transfection Reagents and Equipment Market by Method (Biochemical ... Application (Biomedical, Protein Production), End User - Global ... studies the global market from 2016 to 2021. ... Billion by 2021 from USD 715.4 Million in ...
(Date:1/13/2017)... 2017 The 2016 election resulted in ... states voting in favor of legalizing cannabis for recreational use, ... in the U.S. In addition, the state of ... cannabis products sales. The ArcView Group has published an updated ... cannabis sales in the U.S. last year reached $6.7 billion, a ...
(Date:1/13/2017)... Jan. 12, 2017  Rosen Law Firm, a global ... class action lawsuit on behalf of purchasers of Alexion ... February 10, 2014 through November 9, 2016, inclusive (the ... Alexion investors under the federal securities laws. ... http://rosenlegal.com/cases-991.html or call Phillip Kim, Esq. ...
Breaking Medicine Technology: