Featured Research

from universities, journals, and other organizations

DNA Mutation That Occurs At Beginning Point Of T-cell Lymphoma Identified

Date:
June 30, 2009
Source:
University of Southern California
Summary:
Researchers have identified a key mechanism that causes chromosomes within blood cells to break -- an occurrence that marks the first step in the development of human lymphoma.

Researchers at the Keck School of Medicine of the University of Southern California (USC) have identified a key mechanism that causes chromosomes within blood cells to break—an occurrence that marks the first step in the development of human lymphoma.

The study provides researchers with the clearest insight yet into why these breakages—called chromosomal translocations—occur at a specific points in the chromosome, says principal investigator Michael R. Lieber, M.D., Ph.D., Rita and Edward Polusky Professor in Basic Cancer Research at the Keck School of Medicine.

The study appears as the featured cover article in the June 12 issue of the journal Molecular Cell.

"The new findings go to the heart of why cancers begin. This is an opportunity to see the very beginning step of human lymphoma," Lieber says. "With this information, we can now begin to look at ways to interfere with this process in order to stop the lymphoma and to develop more targeted therapies for treatment."

There are two types of lymphoma: B cell lymphomas and T cell lymphomas. Both B cells and T cells perform vital functions in the immune system by creating antibodies and destroying virus-infected cells. However, the beginning point, or inception, of most human lymphomas occurs when two chromosomes break and the resulting fragments are reassembled in an exchange.

Researchers specifically looked at T cell acute lymphoblastic lymphomas (ALL). ALL accounts for half of all childhood cancers under the age of five, and T cell ALL represents about 10 percent of ALL. The USC scientists identified a specific enzyme known as the RAG complex that occasionally cuts the chromosome at an off-target site, causing lymphocyte (blood) cells to proliferate uncontrollably.

They showed that the RAG complex selects the wrong target largely because the proteins in which the wrong chromosome is wrapped (called chromatin) lures the RAG complex to the wrong site.

"The immune system is very good at its job," Lieber says. "More than ninety-nine percent of the time it gets it right, but it only takes one mistake in one of a hundred million cells to cause a problem. "

The paper follows a similar study, published in the December issue of the journal Cell, in which Lieber and colleagues determined how the most common chromosomal translocation in B cell lymphoma occurs. Researchers at USC have been working for many years to understand the underlying mechanisms that cause blood cancers.

"The goal is to understand translocations in various different forms of lymphoma," Lieber says. "The two papers cover more than half of all human lymphomas. That represents a major step forward in understanding this disease."

The study was funded by the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of Southern California. Note: Materials may be edited for content and length.


Journal Reference:

  1. Noriko Shimazaki, Albert G. Tsai and Michael R. Lieber. H3K4me3 Stimulates the V(D)J Rag Complex for Both Nicking and Hairpinning in trans in Addition to Tethering in cis: Implications for Translocations. Molecular Cell, June 12, 2009 DOI: 10.1016/j.molcel.2009.05.011

Cite This Page:

University of Southern California. "DNA Mutation That Occurs At Beginning Point Of T-cell Lymphoma Identified." ScienceDaily. ScienceDaily, 30 June 2009. <www.sciencedaily.com/releases/2009/06/090612092743.htm>.
University of Southern California. (2009, June 30). DNA Mutation That Occurs At Beginning Point Of T-cell Lymphoma Identified. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2009/06/090612092743.htm
University of Southern California. "DNA Mutation That Occurs At Beginning Point Of T-cell Lymphoma Identified." ScienceDaily. www.sciencedaily.com/releases/2009/06/090612092743.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) 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:
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