Featured Research

from universities, journals, and other organizations

Virus That Can Infect Both Mice And Humans Is Driven To Extinction With Cancer Drug

Date:
September 4, 2002
Source:
Cedars-Sinai Medical Center
Summary:
For decades, scientists have tried to figure out how to stop viruses from spreading. Their efforts have led to the development of drugs that can help to slow the spread of some infections and diseases such as AIDS by preventing viruses from reproducing. But because viruses' genetic machinery has the ability to replicate and mutate so quickly, viruses rapidly become resistant to individual anti-viral drugs.

LOS ANGELES, CA (Embargoed until 5 p.m. EST on September 2, 2002) -- For decades, scientists have tried to figure out how to stop viruses from spreading. Their efforts have led to the development of drugs that can help to slow the spread of some infections and diseases such as AIDS by preventing viruses from reproducing. But because viruses' genetic machinery has the ability to replicate and mutate so quickly, viruses rapidly become resistant to individual anti-viral drugs. Thus, the effectiveness of these drugs is very limited.

Now, researchers currently at Cedars-Sinai Medical Center, and the Universidad Autonoma de Madrid, in Spain, report that treating a common virus with a mutation-causing cancer drug caused the virus to mutate so much that it was no longer able to reproduce and was driven to extinction. The findings, reported in the current issue of the Proceedings of the National Sciences (PNAS), and preceded by a Commentary by Nobel-Prize winning Professor Manfred Eigen from the Max Planck Institut fur biophysikalische Chemie, Goettingen, Germany, may ultimately lead to new ways to treat and eliminate viral infections.

"We found that a specific chemical mutagen caused the virus to mutate so much that the replication process was ultimately aborted," said Pedro Lowenstein, M.D., Ph.D., Director of the Board of Governor's Gene Therapeutics Research Institute at Cedars-Sinai Medical Center. "These findings, may lead, in the future, to ways to stop viruses from reproducing in humans in the same way."

"Although the possibility to exploit high mutation rates in viruses was already known, this and other work is providing the basis for more rapid progress in this field," said collaborator and co-author Esteban Domingo, Ph.D, Director of the Laboratory of Genetic Variability of RNA Viruses at the Center for Molecular Biology 'Severo Ochoa', Universidad Autonoma de Madrid, Spain.

Viruses are genetic entities that can cause a number of infections and diseases in humans such as the common cold, chickenpox, shingles, herpes, polio, influenza and AIDS. Infections occur when a virus comes into contact with a host cell and injects its genetic material, literally taking over the cell's function. Subsequently, the infected cell produces more viral protein and genetic material instead of its usual products.

But for viruses to reproduce and spread, they must make many copies of their genetic material. In RNA viruses, such as those discussed here, this process occurs when a viral enzyme reads the sequence of the viruses' genome within the host cell and transcribes it into a complementary RNA or DNA sequence. Yet, the process is error-prone, as mistakes occur during replication when the genome sequence is read and transcribed, resulting in mutations in the viral genome.

Capitalizing on the viruses' tendency to make errors during the replicating process, the investigators tested two types of mutation-inducing cancer drugs in cells infected with lymphocytic choriomeningitis virus (LCMV), a virus that can infect both mice and humans. To do this, the investigators infected hamster cells, grown in culture, with the virus and treated them with either 5-fluorouracil (FU) or 5-azacytidine (AZC). The viruses' ability to replicate and the amount of mutations that occurred in the viral genomes was then measured and compared at varying doses of either FU or AZC. The researchers found that both FU and AZC increased the number of mutations in all areas of the viruses' genetic machinery even at lower doses. However, only higher doses of FU were able to drive the virus to extinction, while treatment with AZC at any dose level was not effective to eliminate the virus.

"Given that FU eliminated this particular virus, while AZC did not suggests that different mutagens will be more effective than others in the treatment of viruses," commented Dr. Lowenstein. "This work also lays the groundwork for future studies to determine how mutagens actually slow down the replication process and, at the same time, may lead to new treatments that succeed where others have limited effectiveness."

Although viral extinction was likely due to an increase in the mutation rate caused by FU, the investigators were unable to track the viruses' mutations as they progressed closer to extinction.

"This was likely due to the fact that highly mutated genomes are either undetectable with current methods, or that the mutations obtained and detected were already sufficient to block further viral replication," said Dr. Lowenstein.

"That the introduction of more mutations could help combat viral disease seemed totally unrealistic a decade ago. Now, despite obvious difficulties and a lot of work to be done, it is a sound scientific proposition," commented Dr. Domingo.

Cedars-Sinai Medical Center is one of the largest nonprofit academic medical centers in the Western United States. For the fifth straight two-year period, Cedars-Sinai has been named Southern California's gold standard in health care in an independent survey. Cedars-Sinai is internationally renowned for its diagnostic and treatment capabilities and its broad spectrum of programs and services, as well as breakthrough in biomedical research and superlative medical education. Named one of the 100 "Most Wired" hospitals in health care in 2001, the Medical Center ranks among the top 10 non-university hospitals in the nation for its research activities.


Story Source:

The above story is based on materials provided by Cedars-Sinai Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

Cedars-Sinai Medical Center. "Virus That Can Infect Both Mice And Humans Is Driven To Extinction With Cancer Drug." ScienceDaily. ScienceDaily, 4 September 2002. <www.sciencedaily.com/releases/2002/09/020904074147.htm>.
Cedars-Sinai Medical Center. (2002, September 4). Virus That Can Infect Both Mice And Humans Is Driven To Extinction With Cancer Drug. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2002/09/020904074147.htm
Cedars-Sinai Medical Center. "Virus That Can Infect Both Mice And Humans Is Driven To Extinction With Cancer Drug." ScienceDaily. www.sciencedaily.com/releases/2002/09/020904074147.htm (accessed August 21, 2014).

Share This




More Health & Medicine News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) — A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Raw: World's Oldest Man Lives in Japan

Raw: World's Oldest Man Lives in Japan

AP (Aug. 20, 2014) — A 111-year-old Japanese was certified as the world's oldest man by Guinness World Records on Wednesday. Sakari Momoi, a native of Fukushima in northern Japan, was given a certificate at a hospital in Tokyo. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Do More Wedding Guests Make A Happier Marriage?

Do More Wedding Guests Make A Happier Marriage?

Newsy (Aug. 20, 2014) — A new study found couples who had at least 150 guests at their weddings were more likely to report being happy in their marriages. Video provided by Newsy
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Freetown a City on Edge

Ebola-Hit Sierra Leone's Freetown a City on Edge

AFP (Aug. 19, 2014) — Residents of Sierra Leone's capital voice their fears as the Ebola virus sweeps through west Africa. Duration: 00:56 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