Thursday, October 05, 2006

Noble Prize in Medicine

Andrew Z. Fire and Craig C. Mello have won this year's Noble Prize for Medicine for their discovery of RNA interference . See this.

You can view an animated tour through the process of RNA interference here.

Msnbc has an interesting intervew with Andrew Z. Fire here. The interview explains the process of RNA interference and its potential applications. Here is a sample:

NEWSWEEK: You won the Nobel Prize for uncovering the process of RNA interference. Can you explain to our readers exactly what this entails?

Andrew Z. Fire: Our observations built on previous work by others in plants and fungi. When people tried to put extra copies of a gene into a plant, instead of getting more of the result, they got less. It seemed there was a way that the organism had to sense that there were extra copies—and not just extra copies but some that were also probably somehow messed up. So the organism had to be able to detect unwanted activity. And if it sensed this activity, which is going to come out in the form of some kind of RNA [an intermediary between stable DNA, which stores information in our genes, and proteins, which act on the information] that is unusual, it went ahead and got rid of them. We studied something similar with worms.

What did you find?

We wanted to know how an organism can tell the difference between foreign RNA and what's inside. It turns out it's a fairly simple structural distinction. If we took double-stranded RNA and put it into cells, that could shut a gene down pretty efficiently. The organism is looking for RNA where both strands present in the cell (normally, it's just one strand). That was essentially the result. We could put two strands of an RNA in and it would shut down the corresponding gene...The cell not only gets rid of double-stranded material but looks for anything that looks similar and gets rid of it too.

What are the potential applications for humans?

The biggest medium-term application is researchers who are studying a given question. For example, let's say we're interested in an individual cancerous tumor—a population of cells that are doing something against our best interest—and want to know what makes it so we can get rid of it. One way is to go on a gene by gene basis through all the thousands of genes and decrease the function of each one at a time to figure out which are needed for the tumor to grow. The hope in that case is to find the gene that is needed for the tumor but not required for normal cell growth. So far, the experiment has been in a lab. If you had that information and really believed RNA to be a gene-silencing tool, though, you could imagine taking double-stranded RNA into a sick person and making them healthy. People are exploring that, but delivering it is very complicated. Some clinical trials are being done in tissues that are very good at receiving the RNA material like the eye and the liver.

What diseases are being targeted in the clinical trials?

One is macular degeneration, which causes blindness. The reason it's moved so quickly to clinical trials mostly has to do with the ethics of doing clinical trials. No other treatment is approved for macular degeneration. Also, the eye is fairly self-contained. It's easier to test it in the eye in a clinical trial than injecting it into the bloodstream...

This announcement from the Noble Foundation is one additional snapshot of the larger story that is unfolding around us with rapid speed. The genetic revolution is an incredible story of human ingenuity and determination. One that could have a great impact on the life prospects of the genetically disadvantaged.