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 Warming ponds could accelerate climate change
21.02.2017 | University of Exeter

nachricht An alternative to opioids? Compound from marine snail is potent pain reliever
21.02.2017 | University of Utah

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Impacts of mass coral die-off on Indian Ocean reefs revealed

21.02.2017 | Earth Sciences

Novel breast tomosynthesis technique reduces screening recall rate

21.02.2017 | Medical Engineering

Use your Voice – and Smart Homes will “LISTEN”

21.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>