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 Cells migrate collectively by intermittent bursts of activity
30.09.2016 | Aalto University

nachricht The structure of the BinAB toxin revealed: one small step for Man, a major problem for mosquitoes!
30.09.2016 | CNRS (Délégation Paris Michel-Ange)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

Heavy construction machinery is the focus of Oak Ridge National Laboratory’s latest advance in additive manufacturing research. With industry partners and university students, ORNL researchers are designing and producing the world’s first 3D printed excavator, a prototype that will leverage large-scale AM technologies and explore the feasibility of printing with metal alloys.

Increasing the size and speed of metal-based 3D printing techniques, using low-cost alloys like steel and aluminum, could create new industrial applications...

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Paper – Panacea Green Infrastructure?

30.09.2016 | Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

 
Latest News

First-Ever 3D Printed Excavator Project Advances Large-Scale Additive Manufacturing R&D

30.09.2016 | Materials Sciences

New Technique for Finding Weakness in Earth’s Crust

30.09.2016 | Earth Sciences

Cells migrate collectively by intermittent bursts of activity

30.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>