Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stem-cell sentry sounds the alarm to maintain balance between cancer and aging

16.10.2008
Like a sentry guarding the castle walls, a molecular messenger inside adult stem cells sounds the alarm when it senses hazards that could allow the invasion of an insidious enemy: Cancer.

The alarm bell halts the process of cell division in its tracks, preventing an error that could lead to runaway cell division and eventually, tumor formation.

"Our work suggests that to be able to prevent abnormal cell proliferation, which could lead to cancer, stem cells developed this self-checking system, what we're calling a checkpoint," said Yukiko Yamashita of the University of Michigan's Life Sciences Institute.

"And if it looks like the cell is going to divide in the wrong way, the checkpoint senses there's a problem and sends the signal: 'Don't divide! Don't divide!'" said Yamashita, a research assistant professor of life sciences and an assistant professor of cell and developmental biology at the U-M Medical School.

If everything looks OK, the checkpoint allows adult stem-cell division to proceed, providing new cells to replace damaged and worn-out tissues.

Yamashita and her colleagues have not yet identified the molecules that form the checkpoint mechanism. But they've seen it at work in adult stem cells of the fruit-fly testes, so-called germ-line stem cells.

"Aging is too few divisions and cancer is too many divisions, and people have long speculated that some process controls the balance between them," Yamashita said. "We may have found the mechanism that maintains the delicate balance between over-proliferation---which can lead to cancer---and aging."

The team's findings will be published Oct. 15 in the online version of the journal Nature.

If humans possess a similar checkpoint system and if researchers could someday harness it, they could fine-tune the rate of cellular division to control tumor development as well as tissue aging. But Yamashita stressed that no mammal studies of the checkpoint have been undertaken, so talk of potential human applications is highly speculative.

In fruit flies, the checkpoint monitors germ-line stem cells as they're about to divide. It can sense problems that would derail the division process, which is called mitosis.

Under normal conditions, adult stem-cell division creates one new stem cell and one cell committed to develop into a specific tissue type – such as a skin cell, a blood cell or, in this case, a sperm cell. That form of mitosis is called asymmetric division, and it's exactly what stem cells need to maintain a healthy balance between uncommitted and committed cells.

Cell division is controlled in part by the location of a pair of cellular components called centrosomes. They provide the framework that helps direct how chromosomes are distributed between daughter cells during mitosis.

Normally, centrosomes in a dividing stem cell remain perpendicular to an adjoining messenger cell called the hub. Yamashita and her colleagues found that improper orientation of the centrosomes disrupts the mitotic machinery, steering it on a course toward stem-cell over-proliferation and cancer.

The checkpoint mechanism senses when centrosomes are misaligned, then sounds the alarm that stops cell division.

By preventing faulty cell division, the checkpoint helps ward off cancer. But a balance must be struck: If the checkpoint mechanism slows cell division to a trickle, the resulting shortage of new cells will accelerate tissue aging.

"It's a double-edged sword, and both outcomes are bad," she said. "One path leads to cancer and the other leads to aging. And we haven't found a way to avoid aging without getting cancer."

Jim Erickson | EurekAlert!
Further information:
http://www.umich.edu

Further reports about: Aging Alarm Balance Cancer Lead Stem Stem-cell Yamashita centrosomes checkpoint divide fruit flies maintain mechanism sense sounds stem cells tumor formation

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 >>>