Featured Research

from universities, journals, and other organizations

X Rays Reveal Cell's Fight Against Cancer As Struggle Between Pro- And Anti-tumor Proteins

Date:
September 6, 2006
Source:
University of Southern California
Summary:
Molecular biologists document the first step in one type of tumor: a virus homes in on a cell's most important defender, inhibiting its anti-cancer properties.

Lead researcher Xiaojiang Chen, professor in molecular and computational biology in USC College.
Credit: Photo : Philip Channing

If anything in cancer biology can be likened to a cage match, this is it: the battle inside the cell walls between LTag, "The Most Amazing Molecule in the Universe," and p53, "The Guardian of the Genome."

By the painstaking use of X-ray crystallography to track motion in very large molecules, a University of Southern California-led research group has taken a first look at the life-or-death struggle of a cancer-causing protein -- LTag -- and a key tumor suppressor -- p53.

Each villainous LTag (short for large T antigen) single-handedly ties up a tag-team of six p53 molecules, inhibiting their tumor-suppressant role, the researchers report in the Sept. 1 issue of Genes & Development.

Undeterred, the p53 fight back by preventing replication of the virus that produces LTag, known as an oncoprotein for its function in cancer growth.

The champion depends on which side is stronger and healthier.

"If you have a lot of functional p53, you can override large T antigen," said lead researcher Xiaojiang Chen, professor in molecular and computational biology in the USC College of Letters, Arts and Sciences.

Sometimes called the "Guardian of the Genome," a damaged p53 can leave a cell almost defenseless.

"p53 is a very important tumor suppressor that's mutated in a vast majority of all cancers," said James Pipas, professor of biological sciences at the University of Pittsburgh.

It was Pipas who, after studying LTag for many years and marveling at its varied biological functions -- including highly efficient tumor promotion -- named it "The Most Amazing Molecule in the Universe" in one of his presentations.

Pipas called Chen's new study "a very important piece of work" that shows how a healthy cell's tumor defenses break down.

"Understanding exactly how this works is going to be a critical step toward our understanding of tumor genesis," he said.

This, in turn, may lead to new techniques for designing tumor-fighting drugs, Pipas added.

Chen's team was able to describe the interplay between LTag and p53 by crystallizing the complex of one LTag and six p53 molecules, totaling more than 50,000 atoms between them.

"It's quite a technical achievement, because these are fairly large proteins," Pipas said.

Chen said his study gave him new respect for LTag and its parent, Simian Virus 40. SV40 has long been used as a research tool to induce cancers in cell cultures.

"Somehow this virus knows how important p53 is, and has this oncoprotein (LTag) to target it by physically interacting with it and changing its conformation," Chen said.

If the virus succeeds, the result is a new tumor.

Scientists from the University of Colorado and Argonne National Laboratory contributed to the study. Funding for the group's research came from the American Cancer Society.


Story Source:

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


Cite This Page:

University of Southern California. "X Rays Reveal Cell's Fight Against Cancer As Struggle Between Pro- And Anti-tumor Proteins." ScienceDaily. ScienceDaily, 6 September 2006. <www.sciencedaily.com/releases/2006/09/060901164235.htm>.
University of Southern California. (2006, September 6). X Rays Reveal Cell's Fight Against Cancer As Struggle Between Pro- And Anti-tumor Proteins. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2006/09/060901164235.htm
University of Southern California. "X Rays Reveal Cell's Fight Against Cancer As Struggle Between Pro- And Anti-tumor Proteins." ScienceDaily. www.sciencedaily.com/releases/2006/09/060901164235.htm (accessed July 23, 2014).

Share This




More Health & Medicine News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Courts Conflicted Over Healthcare Law

Courts Conflicted Over Healthcare Law

AP (July 22, 2014) Two federal appeals courts issued conflicting rulings Tuesday on the legality of the federally-run healthcare exchange that operates in 36 states. (July 22) Video provided by AP
Powered by NewsLook.com
Why Do People Believe We Only Use 10 Percent Of Our Brains?

Why Do People Believe We Only Use 10 Percent Of Our Brains?

Newsy (July 22, 2014) The new sci-fi thriller "Lucy" is making people question whether we really use all our brainpower. But, as scientists have insisted for years, we do. Video provided by Newsy
Powered by NewsLook.com
Scientists Find New Way To Make Human Platelets

Scientists Find New Way To Make Human Platelets

Newsy (July 22, 2014) Boston scientists have discovered a new way to create fully functioning human platelets using a bioreactor and human stem cells. Video provided by Newsy
Powered by NewsLook.com
Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

Gilead's $1000-a-Pill Drug Could Cure Hep C in HIV-Positive People

TheStreet (July 21, 2014) New research shows Gilead Science's drug Sovaldi helps in curing hepatitis C in those who suffer from HIV. In a medical study, the combination of Gilead's Hep C drug with anti-viral drug Ribavirin cured 76% of HIV-positive patients suffering from the most common hepatitis C strain. Hepatitis C and related complications have been a top cause of death in HIV-positive patients. Typical medication used to treat the disease, including interferon proteins, tended to react badly with HIV drugs. However, Sovaldi's %1,000-a-pill price tag could limit the number of patients able to access the treatment. TheStreet's Keris Lahiff reports from New York. Video provided by TheStreet
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