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 Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society

nachricht New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>