Navigation Links
Osteoporosis drug stops growth of breast cancer cells, even in resistant tumors
Date:6/15/2013

DURHAM, N.C. -- A drug approved in Europe to treat osteoporosis has now been shown to stop the growth of breast cancer cells, even in cancers that have become resistant to current targeted therapies, according to a Duke Cancer Institute study.

The findings, presented June 15, 2013, at the annual Endocrine Society meeting in San Francisco, indicate that the drug bazedoxifene packs a powerful one-two punch that not only prevents estrogen from fueling breast cancer cell growth, but also flags the estrogen receptor for destruction.

"We found bazedoxifene binds to the estrogen receptor and interferes with its activity, but the surprising thing we then found was that it also degrades the receptor; it gets rid of it," said senior author Donald McDonnell, PhD, chair of Duke's Department of Pharmacology and Cancer Biology.

In animal and cell culture studies, the drug inhibited growth both in estrogen-dependent breast cancer cells and in cells that had developed resistance to the anti-estrogen tamoxifen and/or to the aromatase inhibitors, two of the most widely used types of drugs to prevent and treat estrogen-dependent breast cancer. Currently, if breast cancer cells develop resistance to these therapies, patients are usually treated with toxic chemotherapy agents that have significant side effects.

Bazedoxifene is a pill that, like tamoxifen, belongs to a class of drugs known as specific estrogen receptor modulators (SERMs). These drugs are distinguished by their ability to behave like estrogen in some tissues, while significantly blocking estrogen action in other tissues. But unlike tamoxifen, bazedoxifene has some of the properties of a newer group of drugs, known as selective estrogen receptor degraders, or SERDs, which can target the estrogen receptor for destruction.

"Because the drug is removing the estrogen receptor as a target by degradation, it is less likely the cancer cell can develop a resistance mechanism because you are removing the target," said lead author Suzanne Wardell, PhD, a research scientist working in McDonnell's lab.

Many investigators had assumed that once breast cancer cells developed resistance to tamoxifen, they would be resistant to all drugs that target the estrogen receptor, McDonnell explained.

"We discovered that the estrogen receptor is still a good target, even after it resistance to tamoxifen has developed," he said.

The investigators tested a variety of breast cancer cell types, including tamoxifen-sensitive cells that are resistant to the drug lapatinib, another targeted therapy that is used to treat patients with advanced breast cancer whose tumors contain the mutant HER2 gene. These cells had previously been shown to reactivate estrogen signaling in order to acquire drug resistance. In this cell type, bazedoxifene also potently inhibited cell growth.

Paradoxically, in bone tissue, bazedoxifene mimics the action of estrogen, helping protect it from destruction. Because bazedoxifene has already undergone safety and efficacy studies as a treatment for osteoporosis, it may be a viable near-term option for patients with advanced breast cancer whose tumors have become resistant to other treatment options, Wardell reported. In clinical trials, the most often reported side effect was hot flashes in the bazedoxifene treatment groups.


'/>"/>

Contact: Rachel Harrison
rachel.harrison@duke.edu
919-419-5069
Duke University Medical Center
Source:Eurekalert

Related biology news :

1. IOF Worldwide Conference of Osteoporosis Patient Societies opens in Helsinki
2. Program announced for the 4th Asia-Pacific Osteoporosis Meeting in Hong Kong
3. Worlds largest meeting dedicated to osteoporosis and osteoarthritis opens in Rome
4. European Guidance for the diagnosis & management of osteoporosis in postmenopausal women
5. Less than 1 month to start of European Congress on Osteoporosis & Osteoarthritis in Rome
6. 4th Asia-Pacific Osteoporosis Meeting to be led by regions leading bone experts
7. European Congress on Osteoporosis and Osteoarthritis
8. Summit of osteoporosis experts from CIS countries issue 5-point call for action
9. IOF Asia-Pacific Meeting presents new research and advances in osteoporosis management
10. Launch of the EU large-scale integrating project BlueGenics to combat osteoporosis
11. Register now for the key osteoporosis meeting in the Asia-Pacific region
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/4/2017)... NEW YORK , April 4, 2017   ... solutions, today announced that the United States Patent and ... The patent broadly covers the linking of an iris ... the same transaction) and represents the company,s 45 th ... our latest patent is very timely given the multi-modal ...
(Date:3/30/2017)... March 30, 2017 Trends, opportunities and forecast ... behavioral), by technology (fingerprint, AFIS, iris recognition, facial recognition, ... others), by end use industry (government and law enforcement, ... and banking, and others), and by region ( ... Asia Pacific , and the Rest ...
(Date:3/24/2017)... March 24, 2017 The Controller General of Immigration ... Abdulla Algeen have received the prestigious international IAIR Award for ... Continue Reading ... ... Deputy Controller Abdulla Algeen (small picture on the right) have received the ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... The CRISPR-Cas9 system ... experiments and avoiding the use of exogenous expression plasmids. The simplicity of programming ... systematic gain-of-function studies. , This complement to loss-of-function studies, such as with ...
(Date:10/11/2017)...  VMS BioMarketing, a leading provider of patient support solutions, ... Educator (CNE) network, which will launch this week. The VMS ... care professionals to enhance the patient care experience by delivering ... health care professionals to help women who have been diagnosed ... ...
(Date:10/11/2017)... ... October 11, 2017 , ... ... granted orphan drug designation to SBT-100, its novel anti-STAT3 (Signal Transducer and Activator ... osteosarcoma. SBT-100 is able to cross the cell membrane and bind intracellular STAT3 ...
(Date:10/10/2017)... ... October 10, 2017 , ... Dr. Bob Harman, founder and CEO ... Diego Rotary Club. The event entitled “Stem Cells and Their Regenerative ... attendees. Dr. Harman, DVM, MPVM was joined by two human doctors: Peter B. ...
Breaking Biology Technology: