New Gene Tool Stops Liver Damage
Finding May Help Hepatitis, Liver Transplants, and More
Feb. 10, 2003 -- Last year it was the scientific breakthrough of the year. Tomorrow it may be called a new treatment for hepatitis and other liver woes.
It's called RNA interference or RNAi. Discovered only last year, it's an amazing tool. If you know the DNA code for any gene, you can use RNAi to switch that gene off. At least it works that way in the test tube.
Now a team of U.S. and Chinese researchers show that it works in live animals, too. Led by Judy Lieberman, MD, PhD, of Harvard University, the scientists have used a small RNAi molecule -- small interfering RNA or siRNA -- to protect mice from liver failure due to hepatitis. They report their findings in the March issue of Nature Medicine.
The technique, they write, "may be of therapeutic value for preventing and treating acute and chronic liver injury induced by viral and autoimmune hepatitis, alcoholic liver disease, acute and chronic liver failure, and rejection of liver transplants."
Liver damage in hepatitis happens when a self-destruction program gets turned on in liver cells. A single gene -- called Fas -- controls this process. Lieberman's team shows that when siRNA is used to silence Fas, mice are protected from liver damage. The mice get protection even if the siRNA is given after the damage already has started.
Because lots of liver damage happens this way, the researchers suggest that siRNA could have a wide variety of uses. One of the most promising is prevention of rejection after liver transplant.
Further studies are needed before human trials can start. One big obstacle is finding a way to deliver large volumes of siRNA to the human liver.
SOURCE: Nature Medicine, March 2003.