Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCSD Discovery Shows How Embryonic Stem Cells Perform ’Quality Control’ Inspections

27.12.2004


Biologists at the University of California, San Diego have found a fundamental mechanism used by embryonic stem cells to assure that genetically damaged stem cells do not divide and pass along the damage to daughter stem cells.


Photo of mouse embryonic stem cells Credit: Tongxiang Lin, UCSD



Their discovery, detailed in an advance online publication of the journal Nature Cell Biology, solves the longstanding mystery of how embryonic stem cells, which have the potential to divide an unlimited number of times and differentiate to make all of the cell types in the body, are able to avoid duplicating cells that have sustained genetic damage.

“What we discovered is a primary mechanism that allows embryonic stem cells to perform quality control inspections during their self-renewal, the process by which these cells undergo unlimited cellular division to produce an unlimited number of daughter cells,” says Yang Xu, an associate professor of biology at UCSD who headed the research team.


“Since DNA damage can occur during normal cellular propagation as well as after the exposure of cells to DNA-damaging radiation and chemicals, it is critical for the embryonic stem cells to develop stringent mechanisms to ensure the repair of DNA damage and prevent the passage of DNA damage to their daughter cells. Unrepaired DNA damage will cause genetic instability and, ultimately, cellular transformation into cancer cells.”

Xu and his team made their discovery while working with embryonic stem cell lines from mice, which possess the same known properties and capabilities as human embryonic stem cells. They found that a protein, p53, known to play a critical role in the suppression of tumors in both humans and mice, is also used to maintain the genetic stability of embryonic stem cells.

The scientists, who included Tongxiang Lin, a UCSD postdoctoral fellow and the first author of the study, and Connie Chao, a graduate student in Xu’s laboratory, discovered that p53 activated by DNA damage in mouse embryonic stem cells directly suppresses the expression of a gene called Nanog, which is necessary for the self renewal, or unlimited duplication, of these stem cells. The suppression of Nanog promotes embryonic stem cells to differentiate into other cell types.

“The end result of all of these actions by p53 is to deprive embryonic stem cells with DNA damage the ability to self renew themselves and pass the DNA damage onto their daughter cells,” says Xu. “p53 also contributes to the eventual elimination of DNA damage in the embryonic stem cells that have already differentiated into specific cell types, thus preventing the development of cancerous cells.”

“These findings will open new avenues of research for those of us who study mouse embryonic stem cells on how these cells maintain genetic stability and self renewal,” he adds. “They will also provide a foundation for future studies involving human embryonic stem cells of how these cells maintain genetic stability during their self renewal.”

Other scientists involved in the study included Shin’ichi Saito, Sharlyn Mazur and Ettore Appella of the National Cancer Institute in Bethesda, Md., and Maureen Murphy of the Fox Chase Cancer Center in Philadelphia. The study was supported by a grant from the National Cancer Institute.

Yang Xu | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>