A new study has found a possible mechanism for tamoxifen resistance in breast cancer and provides evidence that another cancer drug--gefitinib (Iressa)--may be able to restore tamoxifens anticancer activity. The study appears in the June 16 issue of the Journal of the National Cancer Institute.
Although adjuvant tamoxifen can reduce the risk of death for women with invasive breast cancer by about 15% over 10 to 15 years, many women do not receive any benefit from the drug. Even among patients most likely to benefit from tamoxifen--those with tumors that express the drugs target, the estrogen receptor (ER)--only 40% to 50% actually benefit. Studies have shown that patients with ER-positive tumors that express high levels of HER2/neu and the ER coactivator AIB1 often develop tamoxifen resistance, but the mechanism of the resistance has not been identified.
To find this mechanism, Rachel Schiff, Ph.D. and C. Kent Osborne, M.D., of the Baylor College of Medicine in Houston, and colleagues studied molecular interactions in breast cancer cells that expressed high levels of both HER2 and AIB1. They found that, in these cells, tamoxifen acted like an estrogen agonist and stimulated tumor growth. However, when the breast cancer cells were treated with the receptor tyrosine kinase inhibitor gefitinib, tamoxifen once again acted as an estrogen antagonist and tumor growth was blocked.
Sarah L. Zielinski | EurekAlert!
Laser activated gold pyramids could deliver drugs, DNA into cells without harm
24.03.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences
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24.03.2017 | University of California - San Diego
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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24.03.2017 | Physics and Astronomy