For the biologists only

I was browsing through some NewScientist magazines (they're so much easier to read, like Newsweek.. rather than those dense scientific journals!) and i came across this really exciting piece of news! We all know that siRNAs are widely used to silence genes.. but.. did you know that they've been discovered to be able to OVEREXPRESS genes as well??? here's an abstract of the article..

Turn genes on, turn diseases off

• 07 April 2007
• Bob Holmes
• NewScientist Magazine issue 2598

THE experiment should have been straightforward. Long-Cheng Li was employing the hottest new technique in biology to turn off genes in cells growing in a dish. The trouble was that the opposite was happening. Instead of blocking production of the protein he was targeting, his RNAs seemed to be revving it up. In fact, levels of the protein shot up fivefold - a massive increase.

"At first I thought there must be something wrong with the samples, that we'd mislabelled them or messed up," recalls Li, a molecular biologist at the University of California, San Francisco. So he had his technician do it all again from scratch - with the same result.

That pulled Li up short. RNA interference, as the technique is called, is supposed to turn genes off, not on. All over the world researchers were using RNAi to turn off almost any gene they wanted, and its ...

I'm so sorry i have no access to the full online version of this article. But the magazine info is there.. so u can still find it at libraries ^_^ It's mainly saying that siRNAs that target promoters instead of the gene itself have a chance of having the opposite effect, i.e. overexpression. This phenomenon has been observed by multiple labs, but some scientists remain skeptical over this issue. There has also been no definite 'fool-proof' method for creating such siRNAs as yet. But think about it. if one day siRNAs can be used to overexpress tumor suppressor genes.. there goes cancer!! ^_^