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 , ... Lori R. Somekh, founder ... of ElderCounsel, a national organization of elder law and special needs planning attorneys. “Membership ... rules. It also provides a forum to network with elder law attorneys nationwide,” said ...
(Date:10/13/2017)... N.J. (PRWEB) , ... October 13, 2017 , ... The ... Holly Day Market. Featuring a collection of specialty vendors and unique items from across ... personalized and quality-focused health and wellness services offered by the VNA. The boutique ...
(Date:10/13/2017)... Abilene, Texas (PRWEB) , ... October 13, 2017 , ... ... publication this week that explains one of the most popular and least understood books ... seems like cryptic and puzzling descriptions that have baffled scholars for centuries. Many have ...
(Date:10/13/2017)... ... October 13, 2017 , ... “The Journey: From the ... danger possible to save lost souls in the Philippines. “The Journey: From the Mountains ... a dedicated teacher of the Bible. She has taught all ages and currently teaches ...
(Date:10/12/2017)... ... 12, 2017 , ... CitiDent and San Francisco dentists, Dr. ... Oventus O2Vent technology. As many as 18 million Americans are estimated to suffer ... Oral appliances can offer significant relief to about 75 percent of people with ...
Breaking Medicine News(10 mins):
(Date:10/4/2017)... Korea , Oct. 4, 2017  South Korean-based ... next-generation CPR training aide "cprCUBE" on Kickstarter. The device ... compression during cardiac arrests with better efficiency compared to ... also offers real-time feedback on efficacy of the compression ... crowdfunding campaign has a goal to raise $5,000. ...
(Date:10/2/2017)... 2, 2017  AllianceRx Walgreens Prime, the combined central ... and pharmacy benefit manager Prime Therapeutics LLC (Prime), today ... included the unveiling of new signage at its headquarters ... as at a few other company-owned facilities across the ... patients, some of whom will begin to see the ...
(Date:9/27/2017)... 2017  Commended for their devotion to personalized service, SMP ... number one in the South Florida Business Journal,s 50 Fastest-Growing ... yearly list, the national specialty pharmacy has found its niche.  ... will soon be honored by SFBJ as the 2017 Power ... Set to receive his award in October, Bardisa said of ...
Breaking Medicine Technology: