Featured Research

from universities, journals, and other organizations

Deficiency in p53 anti-tumor protein delays DNA repair after radiation

Date:
April 23, 2013
Source:
H. Lee Moffitt Cancer Center & Research Institute
Summary:
Researchers have found that a deficiency in an important anti-tumor protein, p53, can slow or delay DNA repair after radiation treatment. They suggest that this is because p53 regulates the expression of two enzymes (JMJD2b and SUV39H1) that control the folding of DNA.

Researchers at Moffitt Cancer Center have found that a deficiency in an important anti-tumor protein, p53, can slow or delay DNA repair after radiation treatment. They suggest that this is because p53 regulates the expression of two enzymes (JMJD2b and SUV39H1) that control the folding of DNA.

Related Articles


According to the researchers, p53 is highly inducible by radiation. Activation of p53 stabilizes chromosomes by promoting the repair of heterochromatin DNA, which controls the expression of nearby genes and ensures accurate distribution of chromosomes during cell division.

Their findings, which published online Feb. 4 in Oncogene, are significant because they shed light on the consequence of p53 deficiency that frequently occurs in tumors and further explain the function of p53 in the development of cancer.

Crucial to multicellular organisms, p53 is a tumor suppressor that regulates the cell cycle and helps prevent cancer by maintaining genetic stability and inhibiting gene mutation. But after irradiation, p53 deficiency results in abnormal levels of SUV39H1 and JMJD2b, enzymes that play a vital role in the structure of chromosomes, especially in DNA damage control and repair.

"Different tumor types have variable responses to ionizing radiation," explained study lead author Jiandong Chen, Ph.D., senior member of the Cancer Biology and Molecular Medicine Program at Moffitt. "Radiation therapy is more effective if tumors are defective in repairing damaged DNA. The p53 pathway is compromised to different degrees in all tumors, which may explain the fact that radiation often kills tumor cells more than normal cells."

In this study, the researchers worked with multiple cancer cell lines.

"We found that p53 activates JMJD2b and represses SUV39H1," Chen said. "Depletion of JMJD2b, or sustained expression of SUV39H1, delays the repair of heterochromatin DNA after ionizing radiation," explained Chen. "The DNA repair function of p53 may be particularly important in higher organisms because of the increased complexity of their genomes."

Although they note that there is no general consensus on the relationship between p53 mutation status and treatment response, in certain narrow settings such as breast cancer, p53 mutation is associated with favorable response to chemotherapy.

"We can conclude that the chromatin modifiers SUV39H1 and JMJD2b are important mediators of p53 function in maintaining the stability of highly repetitive DNA sequences, and developing new drugs that target these enzymes may benefit cancer therapy," the researchers wrote.

This work is supported by grants from the National Institutes of Health (CA141244, CA109636).


Story Source:

The above story is based on materials provided by H. Lee Moffitt Cancer Center & Research Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. H Zheng, L Chen, W J Pledger, J Fang and J Chen. p53 promotes repair of heterochromatin DNA by regulating JMJD2b and SUV39H1 expression. Oncogene, 2013 DOI: 10.1038/onc.2013.6

Cite This Page:

H. Lee Moffitt Cancer Center & Research Institute. "Deficiency in p53 anti-tumor protein delays DNA repair after radiation." ScienceDaily. ScienceDaily, 23 April 2013. <www.sciencedaily.com/releases/2013/04/130423091119.htm>.
H. Lee Moffitt Cancer Center & Research Institute. (2013, April 23). Deficiency in p53 anti-tumor protein delays DNA repair after radiation. ScienceDaily. Retrieved March 29, 2015 from www.sciencedaily.com/releases/2013/04/130423091119.htm
H. Lee Moffitt Cancer Center & Research Institute. "Deficiency in p53 anti-tumor protein delays DNA repair after radiation." ScienceDaily. www.sciencedaily.com/releases/2013/04/130423091119.htm (accessed March 29, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, March 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

S. Leone in New Anti-Ebola Lockdown

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015) — Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17 Video provided by AFP
Powered by NewsLook.com
These Popular Antibiotics Can Cause Permanent Nerve Damage

These Popular Antibiotics Can Cause Permanent Nerve Damage

Newsy (Mar. 27, 2015) — A popular class of antibiotic can leave patients in severe pain and even result in permanent nerve damage. Video provided by Newsy
Powered by NewsLook.com
WH Plan to Fight Antibiotic-Resistant Germs

WH Plan to Fight Antibiotic-Resistant Germs

AP (Mar. 27, 2015) — The White House on Friday announced a five-year plan to fight the threat posed by antibiotic-resistant bacteria amid fears that once-treatable germs could become deadly. (March 27) Video provided by AP
Powered by NewsLook.com
House Ready to Pass Medicare Doc Bill

House Ready to Pass Medicare Doc Bill

AP (Mar. 26, 2015) — In rare bipartisan harmony, congressional leaders pushed a $214 billion bill permanently blocking physician Medicare cuts toward House passage Thursday, moving lawmakers closer to resolving a problem that has plagued them for years. (March 26) Video provided by AP
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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