Featured Research

from universities, journals, and other organizations

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

Date:
January 7, 2005
Source:
University Of California, San Diego
Summary:
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

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.

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.


Story Source:

The above story is based on materials provided by University Of California, San Diego. Note: Materials may be edited for content and length.


Cite This Page:

University Of California, San Diego. "UCSD Discovery Shows How Embryonic Stem Cells Perform 'Quality Control' Inspections." ScienceDaily. ScienceDaily, 7 January 2005. <www.sciencedaily.com/releases/2005/01/050106111558.htm>.
University Of California, San Diego. (2005, January 7). UCSD Discovery Shows How Embryonic Stem Cells Perform 'Quality Control' Inspections. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2005/01/050106111558.htm
University Of California, San Diego. "UCSD Discovery Shows How Embryonic Stem Cells Perform 'Quality Control' Inspections." ScienceDaily. www.sciencedaily.com/releases/2005/01/050106111558.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
Powered by NewsLook.com
How to Master Motherhood With the Best Work/Life Balance

How to Master Motherhood With the Best Work/Life Balance

TheStreet (Apr. 22, 2014) In the U.S., there are more than 11 million couples trying to conceive at any given time. From helping celebrity moms like Bethanny Frankel to ordinary soon-to-be-moms, TV personality and parenting expert, Rosie Pope, gives you the inside scoop on mastering motherhood. London-born entrepreneur Pope is the creative force behind Rosie Pope Maternity and MomPrep. She explains why being an entrepreneur offers the best life balance for her and tips for all types of moms. Video provided by TheStreet
Powered by NewsLook.com
Catching More Than Fish: Ugandan Town Crippled by AIDS

Catching More Than Fish: Ugandan Town Crippled by AIDS

AFP (Apr. 22, 2014) The village of Kasensero on the shores of Lake Victoria was where HIV-AIDS was first discovered in Uganda. Its transient population of fishermen and sex workers means the nationwide programme to combat the virus has had little impact. Duration: 02:30 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins