Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stanford scientists flick genetic switch; may lead to new disease treatments

04.07.2002


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.

Amy Adams | EurekAlert!
Further information:
http://mednews.stanford.edu
http://med-www.stanford.edu/MedCenter/MedSchool/

More articles from Life Sciences:

nachricht Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery
20.01.2017 | GSI Helmholtzzentrum für Schwerionenforschung GmbH

nachricht Seeking structure with metagenome sequences
20.01.2017 | DOE/Joint Genome Institute

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

Bodyguards in the gut have a chemical weapon

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>