The research is significant in helping determine why tamoxifen and other synthetic estrogens are linked to increased rates of endometriosis and uterine cancer, and identifies a pathway that could be targeted in drug therapies for those diseases, researchers say.
Findings are published in the July 1, 2009 issue of "Cancer Research," the journal of the American Association for Cancer Research. The paper also can be found online at http://cancerres.aacrjournals.org/current.shtml.
The research found that when activated by estrogens, endometrial cells obtained from patients suffering from endometriosis or human uterine cancer cells initiate a previously unknown cascade of signals that leads to cellular replication and further estrogen production, the paper says.
The ensuing cycle leads to abnormal growth of the cells lining the uterus, or endometrium, which occurs in endometriosis and uterine cancer, according to senior author Holly A. Ingraham, PhD, a professor in the UCSF School of Medicine's Department of Cellular and Molecular Pharmacology.
"It turns out that displaced endometrial cells, such as those used in this study, are estrogen factories," said Ingraham, who also is affiliated with the UCSF Helen Diller Family Comprehensive Cancer Center and the UCSF Center for Reproductive Sciences. "They pump out estrogen in a feed-forward pathway, so the more estrogen they produce, the more estrogen they're capable of producing."
While this pathway was previously unknown, Ingraham said a June 2009 paper led by researchers at the University of New Mexico and published in the journal "Nature Chemical Biology" showed that blocking the GPR30 receptor in this pathway decreases uterine proliferation in a mouse. The two together, she said, validate what researchers now think may be a key area in addressing both uterine cancer and endometriosis.
Uterine cancer is the fourth most common cancer in women, with more than 37,000 women being diagnosed each year in the United States alone, according to data from the Centers for Disease Control.
Endometriosis, in which endometrial cells grow in areas other than the uterus, is the most common gynecological disease and affects more than 5.5 million women in North America, according to the National Institutes of Health. The disease often causes severe pain and can lead to infertility.
Working in collaboration with clinicians at Northwestern University in Chicago, the UCSF team analyzed cells from women with ectopic endometriosis. By studying those patients' endometrial cells, the team was able to identify an unusual, circular pathway involving these cells, the transmembrane estrogen receptor GPR30 and the nuclear receptor SF-1.
The researchers propose that this pathway increases local concentrations of estrogen and, together with classic estrogen-receptor signaling, control the proliferative effects of these estrogens in promoting endometriosis and endometrial cancers.
The UCSF team used a unique chemical biology approach, making use of a tamoxifen-like compound developed in the laboratory of co-author Thomas Scanlan, PhD, who is affiliated with both the UCSF Department of Pharmaceutical Chemistry and the Department of Chemical Biology at the Oregon Health Sciences University in Portland.
"Tamoxifen and other synthetic estrogens have been known to increase the risk of uterine cancer, but until now, we didn't know why that was on a cellular level," Ingraham said. "We think this pathway is going to be an important one in solving that mystery."
The lead investigator on the paper was Benjamin C. Lin. Lin and co-author Sandra C. Tobias are affiliated with the Department of Pharmaceutical Chemistry at UCSF. Other co-authors are Miyuki Suzawa, in the UCSF Department of Cellular and Molecular Pharmacology; Raymond D. Blind in the UCSF Department of Pharmaceutical Chemistry and Department of Cellular and Molecular Pharmacology; and Serdar E. Bulun, in the Department of Obstetrics and Gynecology, Feinberg School of Medicine at Northwestern University.
The authors report no potential conflicts of interest in this research.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. For further information, visit http://www.ucsf.edu.
Kristen Bole | EurekAlert!
First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf
Do microplastics harbour additional risks by colonization with harmful bacteria?
05.04.2018 | Leibniz-Institut für Ostseeforschung Warnemünde
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
25.04.2018 | Physics and Astronomy
25.04.2018 | Physics and Astronomy
25.04.2018 | Information Technology