Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Team Identifies New Breast Cancer Tumor Suppressor and How it Works

27.06.2011
Researchers have identified a protein long known to regulate gene expression as a potent suppressor of breast cancer growth. Their study, in the journal Oncogene, is the first to demonstrate how this protein, known as Runx3, accomplishes this feat.

“People suggested that Runx3 might be a tumor suppressor in breast cancer because they found that it is down-regulated in a lot of breast cancer cell lines and breast cancer tissues,” said University of Illinois medical biochemistry professor Lin-Feng Chen, who led the study.

But no previous studies uncovered direct evidence to support that idea, he said.
In the new study, Chen and his colleagues at Nagasaki University discovered that a significant proportion of mice lacking one of two Runx3 genes spontaneously developed mammary gland tumors at 14 or 15 months of life – an age corresponding to age 40 to 50 in humans.

“We found mammary tumors growing in about 20 percent of the female mice lacking a copy of the Runx3 gene,” Chen said. None of the mice with two normal copies of the gene developed tumors.

The researchers also found that estrogen receptor alpha (ER-alpha), a well-known culprit in the development of many breast tumors, was up-regulated in the mouse tumors. ER-alpha is overexpressed in about 75 percent of human cases of breast cancer, and enhanced ER-alpha expression in normal breast tissue is associated with an increased risk of breast cancer, Chen said.

Circulating estrogen binds to ER-alpha and initiates a chain of events that alter gene expression in the targeted cell. This is a normal part of cellular signaling, but in ER-positive breast cancers, the overexpression of ER-alpha leads to enhanced tumor cell survival, growth and proliferation.

The researchers found that when Runx3 was re-introduced into ER-alpha positive breast cancer cell lines, it suppressed the growth of the cancer cells and inhibited the potential of the cancer cells to form tumors in the mouse. Further experiments revealed that Runx3 actually targeted ER-alpha signaling by inducing the degradation of ER-alpha.

“By regulating the cellular levels of ER-alpha, Runx3 appears to control the cell’s response to circulating estrogen, thus playing an important role in the onset of breast cancer,” Chen said.

Chen sees three potential benefits that spring from this study. First, the researchers have discovered a mouse model of spontaneously occurring mammary tumors that corresponds to an age of increased risk of breast cancer in humans.

Second, Chen hopes to develop a simple test to measure Runx3 levels in mammary tissue.

“We know from other people’s studies that Runx3 is inactivated in the early stages of breast cancer,” he said. “So we might be able to use Runx3 as a biomarker of early stage breast cancer.”

And third, since the Runx3 gene appears to be intact but inactivated in breast cancer, future studies will focus on reversing its inactivation, Chen said.
“If you can reactivate Runx3, then you can suppress tumor growth,” he said.
The study team also included researchers from the University of Pittsburgh Medical Center and the National University of Singapore.

The National Institutes of Health and the U. of I. Campus Research Board funded this study.

The paper, “RUNX3 Acts as a Tumor Suppressor in Breast Cancer by Targeting Estrogen Receptor Alpha,” is available from the U. of I. News Bureau.

Diana Yates | University of Illinois
Further information:
http://www.illinois.edu.

Further reports about: Cancer ER-alpha Runx3 Runx3 genes breast cancer cancer cells early stage suppressor

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>