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:8/18/2017)... ... August 18, 2017 , ... August ... “Vision & Hearing,” advocating for active, healthy lifestyles and highlighting the importance of ... individuals with hearing impairments and shares the latest innovations in hearing aid technology. ...
(Date:8/18/2017)... ... August 18, 2017 , ... ... financial consultations to communities throughout the greater DC region, is inaugurating a “New ... of rescuing local animals and training them to be companions for veterans in ...
(Date:8/18/2017)... IN (PRWEB) , ... August 18, 2017 , ... The ... communities in northwest Indiana, is campaigning in support of Campagna Academy in a charity ... to as the “Hoosier Boys’ Town of Indiana,” Campagna Academy is a nonprofit organization ...
(Date:8/18/2017)... Boca Raton, Fl (PRWEB) , ... August 18, ... ... nation’s largest network of highly trained practitioners specializing in bioidentical hormone replacement therapy ... symptoms associated with hormone imbalance and conditions of aging, such as menopause, andropause, ...
(Date:8/18/2017)... ... August 18, 2017 , ... ... call tracking and monitoring solutions, announced today the launch of a redesigned corporate ... modern navigation and aesthetic, fully responsive design, and an enhanced search directory for ...
Breaking Medicine News(10 mins):
(Date:8/8/2017)... 2017   Second-quarter ... (GAAP) loss per share from continuing operations ... increased 16 percent to $110 million ... percent to $161 million ... continuing operations increased 8 percent to $0.93 ...
(Date:8/7/2017)... (NYSE: DPLO), the nation,s largest independent specialty pharmacy, announced financial ... unless otherwise noted, are to the quarter ended June 30, ... 2017 Highlights include: Revenue of $1,126 ... Total prescriptions dispensed of 220,000, compared to 241,000 ... Gross profit per prescription dispensed of $371, ...
(Date:8/3/2017)...  Opioid addiction and other drugs of abuse, blood ... threatening outcomes, were problems taken on directly as laboratory ... support them, met this week. This according to Kalorama ... of abuse, procalcitonin and acute kidney injury were key ... meeting in San Diego, CA. ...
Breaking Medicine Technology: