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:10/13/2017)... ... October 13, 2017 , ... “America On The Brink”: the ... “America On The Brink” is the creation of published author, William Nowers. Captain ... As a WWII veteran, he spent thirty years in the Navy. Following his ...
(Date:10/12/2017)... ... October 12, 2017 , ... Planet Fitness, one of the ... today its plans to open a flagship location in Covington, LA at 401 N. ... To Go store next to Office Depot in the Holiday Square shopping center. Its ...
(Date:10/12/2017)... , ... October 12, 2017 , ... The American College ... to Carol Friedman, PhD, FACMI, during the Opening Session of AMIA’s Annual Symposium in ... , In honor of Morris F. Collen, a pioneer in the field of medical ...
(Date:10/12/2017)... ... October 12, 2017 , ... Dr. Parsa ... contributed a medical article to the newly revamped Cosmetic Town journal ... the hair transplant procedure known as Follicular Unit Extraction (FUE). , ...
(Date:10/12/2017)... FL (PRWEB) , ... October 12, 2017 , ... On ... holding a treadmill relay – Miles by Moonlight to raise money for the American ... $300 or more. , Teams will work together to keep their treadmills moving ...
Breaking Medicine News(10 mins):
(Date:9/19/2017)... Sept. 19, 2017   ZirMed Inc ., a recognized ... announced that it has been ranked #1 by its users ... Rankings 2017 User Survey. ZirMed was recognized as the ... hospitals and medical centers over 200 beds and holds one ... technology user survey history. ...
(Date:9/18/2017)... , Sept. 18, 2017 EpiVax, ... of bioinformatics and immune engineering, today announced ... influenza A (H7N9) vaccine. ... to seasonal influenza and presents a challenge ... prior exposure to be effective. Using state-of-the-art ...
(Date:9/12/2017)... NEW YORK , Sept. 12, 2017   EcoVadis , the ... chains, has published the first annual edition of its Global CSR Risk ... 20,400 companies evaluated by EcoVadis, based on Scorecard Ratings that analyzed nearly ... ... Performance Index ...
Breaking Medicine Technology: