Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tamoxifen-resistant breast cancer reversed when drug paired with anti-malaria agent

13.06.2014

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.

###

The study is supported by a Department of Defense Breast Cancer Research Program Postdoctoral Fellowship (BC112023) and awards from the US Department of Health and Human Services (R01-CA131465 and U54-CA149147).

The authors have no conflicts of interest.

About Georgetown Lombardi Comprehensive Cancer Center

Georgetown Lombardi Comprehensive Cancer Center, part of Georgetown University Medical Center and MedStar Georgetown University Hospital, seeks to improve the diagnosis, treatment, and prevention of cancer through innovative basic and clinical research, patient care, community education and outreach, and the training of cancer specialists of the future. Georgetown Lombardi is one of only 41 comprehensive cancer centers in the nation, as designated by the National Cancer Institute (grant #P30 CA051008), and the only one in the Washington, DC area. For more information, go to http://lombardi.georgetown.edu.

About Georgetown University Medical Center

Georgetown University Medical Center (GUMC) is an internationally recognized academic medical center with a three-part mission of research, teaching and patient care (through MedStar Health). GUMC's mission is carried out with a strong emphasis on public service and a dedication to the Catholic, Jesuit principle of cura personalis -- or "care of the whole person." The Medical Center includes the School of Medicine and the School of Nursing & Health Studies, both nationally ranked; Georgetown Lombardi Comprehensive Cancer Center, designated as a comprehensive cancer center by the National Cancer Institute; and the Biomedical Graduate Research Organization, which accounts for the majority of externally funded research at GUMC including a Clinical and Translational Science Award from the National Institutes of Health.

Karen Teber | Eurek Alert!

More articles from Health and Medicine:

nachricht An experimental Alzheimer's drug reverses genetic changes thought to spur the disease
04.05.2016 | Rockefeller University

nachricht Research points to a new treatment for pancreatic cancer
04.05.2016 | Purdue University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nuclear Pores Captured on Film

Using an ultra fast-scanning atomic force microscope, a team of researchers from the University of Basel has filmed “living” nuclear pore complexes at work for the first time. Nuclear pores are molecular machines that control the traffic entering or exiting the cell nucleus. In their article published in Nature Nanotechnology, the researchers explain how the passage of unwanted molecules is prevented by rapidly moving molecular “tentacles” inside the pore.

Using high-speed AFM, Roderick Lim, Argovia Professor at the Biozentrum and the Swiss Nanoscience Institute of the University of Basel, has not only directly...

Im Focus: 2+1 is Not Always 3 - In the microworld unity is not always strength

If a person pushes a broken-down car alone, there is a certain effect. If another person helps, the result is the sum of their efforts. If two micro-particles are pushing another microparticle, however, the resulting effect may not necessarily be the sum their efforts. A recent study published in Nature Communications, measured this odd effect that scientists call “many body.”

In the microscopic world, where the modern miniaturized machines at the new frontiers of technology operate, as long as we are in the presence of two...

Im Focus: Tiny microbots that can clean up water

Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.

Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...

Im Focus: ORNL researchers discover new state of water molecule

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.

In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...

Im Focus: Bionic Lightweight Design researchers of the Alfred Wegener Institute at Hannover Messe 2016

Honeycomb structures as the basic building block for industrial applications presented using holo pyramid

Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The “AC21 International Forum 2016” is About to Begin

27.04.2016 | Event News

Soft switching combines efficiency and improved electro-magnetic compatibility

15.04.2016 | Event News

Grid-Supportive Buildings Give Boost to Renewable Energy Integration

12.04.2016 | Event News

 
Latest News

New fabrication and thermo-optical tuning of whispering gallery microlasers

04.05.2016 | Physics and Astronomy

Introducing the disposable laser

04.05.2016 | Physics and Astronomy

A new vortex identification method for 3-D complex flow

04.05.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>