New cause of Tamoxifen resistance is found

Aug 13, 2007

U.S. scientists have discovered a new mechanism for resistance to Tamoxifen and Faslodex endocrine or anti-hormonal breast cancer therapies.

The researchers at the Lombardi Comprehensive Cancer Center at the Georgetown University Medical Center said their findings might allow oncologists to screen women for responsiveness to such treatments, and provide clues to reversing resistance.

The research, led by Professor Robert Clarke, indicates a gene -- X-box binding protein-1, or XBP1 -- previously thought to be unrelated to breast cancer might be responsible for some resistance to endocrine therapy.

The researchers said the gene is an alternatively spliced transcription factor that participates in a stress-signaling pathway to protect cells from damage. Clarke and his colleagues determined over-expression of the spliced variant of the gene in estrogen receptor-positive breast cancer cells led to reduced sensitivity to Tamoxifen and Faslodex.

The study was published online in the July 27 issue of the Journal of the Federation of American Societies for Experimental Biology.

Copyright 2007 by United Press International

Explore further: Prosocial internet support group not beneficial for breast cancer

add to favorites email to friend print save as pdf

Related Stories

Clue to unusual drug-resistant breast cancers found

Oct 08, 2010

Researchers at the University of Illinois at Chicago College of Medicine have found how gene expression that may contribute to drug resistance is ramped up in unusual types of breast tumors. Their findings may offer new therapy ...

Study: 2 good choices to prevent breast cancer

Apr 19, 2010

(AP) -- Older women at higher risk for breast cancer now have two good drug options for preventing the disease, but they will have to weigh the trade-offs, a major study shows.

How breast cancer cells evade therapeutic attacks

Mar 31, 2010

Tumour cells depend upon estrogens to survive and proliferate in about 70% of all breast cancer cases. The most frequently used treatment to fight this variety of tumours relies on anti-estrogens such as tamoxifen. However, ...

Hormone-blocking drug reduces breast cancer risk

Jun 04, 2011

(AP) -- Millions of women at higher-than-usual risk of breast cancer have a new option for preventing the disease. Pfizer Inc.'s Aromasin cut the risk of developing breast cancer by more than half, without the side effects ...

Recommended for you

Marker polyps do not cause cancer

1 hour ago

Although serrated polyps usually are associated with colorectal cancer, it turns out that such polyps are themselves not dangerous, according to a Norwegian study released this week in BMJ Gut.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.