Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New subtype of breast cancer responds to targeted drug

02.03.2010
A newly identified cancer biomarker could define a new subtype of breast cancer as well as offer a potential way to treat it, say researchers at Washington University School of Medicine in St. Louis. Their findings will be published in the March 1 online early edition issue of the Proceedings of the National Academy of Sciences.

The research could further refine what recent breast cancer research has concluded: that breast cancer is not one disease, but many. So far, research has firmly established that at least five subtypes of breast cancer exist, each having distinct biological features, clinical outcomes and responses to traditional therapies.

The biomarker identified by the Washington University researchers is found frequently in breast cancers and especially in those that have poorer outcomes. It stems from overactivation of a gene called LRP6 (low-density lipoprotein receptor-related protein 6), which stimulates an important cell-growth signaling pathway. LRP6 can be inhibited by a protein discovered in the same laboratory, which could become an effective drug against the breast cancer type, the researchers say.

"We found increased expression of the LRP6 gene in about a quarter of breast cancer specimens we examined, and we think LRP6 overexpression could be a marker for a new class of breast cancer," says Guojun Bu, Ph.D., professor of pediatrics and of cell biology and physiology. "In addition, we found that this biomarker is often associated with breast cancers that are either harder to treat or more likely to recur. We already have an agent that seems to be effective against LRP6-overexpressing tumors, which could someday become a therapy for tumors that right now have few treatment options."

The research was conducted primarily by Chia-Chen Liu, a graduate student in the Bu lab, who is a fellow in the Cancer Biology Pathway Program at the Siteman Cancer Center at Washington University School of Medicine and Barnes-Jewish Hospital.

The researchers' analysis of human breast cancer tissue samples found significant increases in LRP6 levels in 20 percent to 36 percent of the tumors. LRP6 was increased more frequently in ER (estrogen receptor)-negative or HER2 (human epidermal growth factor receptor 2)-negative samples. LRP6 was also increased more frequently in so-called triple-negative breast tumor samples, which test negative for ER, HER2 and PR (progesterone receptor).

In general, patients who have triple-negative breast cancers have an increased risk of disease recurrence after initial treatment and a poorer prognosis. Furthermore, although ER-positive and HER2-positive tumors can be targeted with specific therapies, ER-negative and HER2-negative tumors cannot. So it appears that LRP6 overexpression is often associated with tumors that are currently difficult to treat, says Bu.

Research in the lab had earlier discovered a protein that binds to and inhibits LRP6. This study showed that the protein, called Mesd (mesoderm development), was able to slow the growth of breast cancer cells in the laboratory and to inhibit mammary tumor growth in laboratory mice.

Importantly, mice treated with Mesd did not experience any of the known side effects, such as bone lesions, skin disorders or intestinal malfunctions, associated with inhibition of this growth pathway.

"Our work introduces Mesd as a promising antitumor agent that might be further developed for breast cancer therapy," Bu says. "It would be analogous to such successful breast cancer therapies as Herceptin (trastuzumab), which specifically targets HER2-positive breast cancer."

The researchers also found that a small segment of Mesd has the same effect as the larger molecule. This segment, or peptide, is more stable than the whole protein molecule and can be easily synthesized.

The researchers have patented the protein and the peptide through the university's Office of Technology Management. Recently, Raptor Pharmaceutical Corp. licensed Mesd from the university to develop it for clinical use.

Liu C-C, Prior J, Piwnica-Worms D, Bu G. LRP6 overexpression defines a class of breast cancer subtype and is a target for therapy. Proceedings of the National Academy of Sciences. March 1, 2010 (advance online publication).

Funding from the National Institutes of Health and the Siteman Cancer Center supported this research.

Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked third in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.

Siteman Cancer Center is the only federally designated Comprehensive Cancer Center within a 240-mile radius of St. Louis. Siteman Cancer Center is composed of the combined cancer research and treatment programs of Barnes-Jewish Hospital and Washington University School of Medicine. Siteman has satellite locations in West County and St. Peters, in addition to its full-service facility at Washington University Medical Center on South Kingshighway.

Gwen Ericson | EurekAlert!
Further information:
http://www.wustl.edu

Further reports about: Barnes-Jewish Cancer HER2 HER2-positive LRP6 Medicine Science TV breast cancer cancer research

More articles from Health and Medicine:

nachricht Purdue cancer identity technology makes it easier to find a tumor's 'address'
16.11.2018 | Purdue University

nachricht Microgel powder fights infection and helps wounds heal
14.11.2018 | Michigan Technological 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: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>