Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New function for colon cancer gene found

21.01.2008
Dartmouth Medical School research reveals new role for gatekeeper gene APC

Dartmouth Medical School geneticists have discovered a striking turnabout role for a gatekeeper known to put on the brakes for colon cancer. Flaws in a gene called adenomatous polyposis coli (APC), which normally prevents excessive cell growth, are thought to trigger development of most colorectal cancers.

But in an about face, the tumor suppressor gene also has a second task, the researchers found, as a gas pedal that accelerates signaling between cells. This novel duality is reported in the January 18 issue of Science by a team led by Dr. Yashi Ahmed, assistant professor of genetics at DMS.

“Colon cancer is the second most frequent cause of cancer-related death in the United States,” said Ahmed. “Understanding the normal role of APC and what’s happening to cells that have lost the gene can help us identify therapeutic targets for drug action against this common cancer.”

... more about:
»APC »Polyp »Second »Signaling »colon cancer

APC was first identified in families with a hereditary predisposition to develop colon cancer. Family members are born with an error in one of their two APC gene copies, but are fine as long as the other gene copy is normal. However, many of their colon cells develop a second defective gene. As a result, by their teens and twenties these individuals get hundreds to thousands of colon growths--called polyps--some of which invariably progress to cancer, so their colon is usually removed when they are in their twenties.

But these types of polyps that have a strong association with cancer are not limited to hereditary colon cancer. By age 60, according to Ahmed, up to 40 percent of the general population will have at least one such polyp with mutations in both APC genes. Fortunately, with a colonoscopy to view the colon many polyps can be removed in their early stages, before they become cancer.

APC is part of a vital signaling pathway that coordinates cell growth in all animals—from flies through people. During embryonic development, this pathway causes cells to grow and differentiate to become the kind of cells they should be. In many adult cells, however, the pathway should be turned off, and APC puts the brakes on the pathway to stop cell growth.

The researchers devised strategies to explore the molecular workings of APC in the fruit fly, a simple animal with rapid breeding time that offers many advantages in the laboratory. When they remove or reduce APC, they see fruit flies with no wings, peculiar abdomens and many other oddities.

However, APC defects found in colonic polyps have an unusual feature. Generally, gene mutations can disrupt an entire protein, but in colon cancers, only half the APC protein is lost, while the other half remains, Ahmed explains. Her work in fruit flies suggests a reason for this unexplained phenomenon.

“We found that APC has a second, new job. It not only puts the brake on cell signaling, but also gives some gas. These two functions are controlled by different parts of the protein. In the colon cancers, the brake part of the APC protein is lost, but there is strong pressure to retain the give-it-some-gas portion,” Ahmed said.

Indeed, the DMS team’s data suggest that this new “gas” facet is also present in the human APC protein, reinforcing APC’s role as a regulator that promotes or suppresses cell growth. Future studies on how APC balances signals may help benefit treatments not only for colon tumors, but also for birth defects, since the signaling pathway regulated by APC affects nearly all tissues during development.

Hali Wickner | EurekAlert!
Further information:
http://www.dartmouth.edu

Further reports about: APC Polyp Second Signaling colon cancer

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

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

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>