Featured Research

from universities, journals, and other organizations

Stanford Scientists Flick Genetic Switch; May Lead To New Disease Treatments

Date:
July 4, 2002
Source:
Stanford University Medical Center
Summary:
Genes that are inappropriately turned on play a critical role in triggering some diseases. For researchers, the trick is learning how to deactivate these genes to treat illnesses. In a step toward reaching that goal, scientists at Stanford University Medical Center have developed a gene-therapy technique to switch off genes in mice. The finding could potentially lead to ways of treating such diseases as cancer, hepatitis C and AIDS.

STANFORD, Calif. - Genes that are inappropriately turned on play a critical role in triggering some diseases. For researchers, the trick is learning how to deactivate these genes to treat illnesses. In a step toward reaching that goal, scientists at Stanford University Medical Center have developed a gene-therapy technique to switch off genes in mice. The finding could potentially lead to ways of treating such diseases as cancer, hepatitis C and AIDS.

In plants and lower organisms such as flies or worms, researchers can experimentally switch off genes by inserting RNA. Genes normally produce RNA molecules, which the cell uses as a template to create proteins. The injected RNA interferes with the usual order of events and prevents protein from being made - effectively shutting down the gene.

"RNA inhibition has been shown to work in lower organisms, but there was some question about whether it would work in mammals," said Mark Kay, MD, PhD, professor of genetics and pediatrics at Stanford.

Initial attempts to use RNA inhibition in mice were unsuccessful, but when Anton McCaffrey, PhD, joined Kay's lab as a postdoctoral fellow he decided to give RNA inhibition another chance. His results will be published in the July 4 issue of Nature.

To observe the RNA inhibition process, McCaffrey injected mice with a firefly gene called luciferase that makes a light-producing protein. In half the mice, he also injected RNA that inhibits luciferase production. In mice receiving both luciferase and the RNA, whole-body scans showed 80 percent to 90 percent less light compared to mice that received the luciferase gene alone.

In a related experiment, McCaffrey hooked the luciferase gene to a small part of a gene from the hepatitis C virus and injected the hybrid gene into mice along with RNA that is specific to the DNA found in hepatitis C. Once again, mice that received both the gene and the RNA produced significantly less light than mice receiving only the luciferase gene. This experiment suggests that RNA inhibition could be used to deactivate genes from a virus such as hepatitis C or HIV, Kay said. By deactivating genes used by the virus to replicate, researchers could halt an infection in its tracks.

Kay added that although these results look promising, they rely on injected RNA. "RNA doesn't last long in cells," he said. The problem is that in order for the RNA inhibition to work, two RNA molecules must be paired to form a double-stranded molecule. An easier approach would be to inject DNA, which is more durable than RNA, and have the DNA produce the proper RNA. Usual methods of injecting DNA, however, produce single-stranded RNA, which is useless for inhibition - a problem the scientists have worked to solve.

McCaffrey and Kay devised a way around this dilemma after consulting with a colleague. The team injected mice with a DNA molecule that produces an unusual RNA which doubles back on itself like a hairpin to make a single, double-stranded molecule. Injecting this novel RNA into mice was as effective at inhibiting the luciferase gene as injecting double-stranded RNA. What's more, even after the hairpin RNA breaks down, the DNA remains in the cell and continues producing new RNA.

Kay said that this initial work is a proof of concept. "The ultimate goal is to use this to treat a disease," Kay said. "We can do this by placing these molecules into standard gene-therapy vectors." As examples, he said researchers could deactivate virus genes or genes involved in cancer. Kay added that methods of delivering DNA to cells are currently being tested and could potentially be used to provide RNA inhibition, staving off or even preventing some diseases.

###

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at http://mednews.stanford.edu.


Story Source:

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


Cite This Page:

Stanford University Medical Center. "Stanford Scientists Flick Genetic Switch; May Lead To New Disease Treatments." ScienceDaily. ScienceDaily, 4 July 2002. <www.sciencedaily.com/releases/2002/07/020704084454.htm>.
Stanford University Medical Center. (2002, July 4). Stanford Scientists Flick Genetic Switch; May Lead To New Disease Treatments. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2002/07/020704084454.htm
Stanford University Medical Center. "Stanford Scientists Flick Genetic Switch; May Lead To New Disease Treatments." ScienceDaily. www.sciencedaily.com/releases/2002/07/020704084454.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
West Africa Gripped by Deadly Ebola Outbreak

West Africa Gripped by Deadly Ebola Outbreak

AFP (July 28, 2014) The worst-ever outbreak of the deadly Ebola epidemic grips west Africa, killing hundreds. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com
Google's Next Frontier: The Human Body

Google's Next Frontier: The Human Body

Newsy (July 27, 2014) Google is collecting genetic and molecular information to paint a picture of the perfectly healthy human. Video provided by Newsy
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