Testifiable, and falsifiable.
- Sidney Hagen:"My point on testifiable, and falsifiable."
Brian: The story of the discovery dates back to 1990, but the real
breakthrough occurred in 1998, when Andrew Fire, at the Carnegie
Institution, affiliated to the Johns Hopkins University in Baltimore, found=
that RNA a close cousin of DNA, the molecule of inheritance could
switch off genes.
Dr Fire coined the phrase "RNA interference" and explained it by
suggesting that genes can be selectively silenced. That would mean
defective genes that cause tumours, or genes necessary for a virus to
replicate in a cell, could be turned off.
But the real breakthrough occurred in experiments this year which
involved testing the idea on human cells Dr Fire had shown it only on a
microscope nematode worm. Two independent teams of researchers
demonstrated that human cells in a test tube could be made to resist
infection with HIV, and a third set of researchers found that it worked
against the polio virus in a way that they believe will prove effective
against other human viruses.
"In the past year we've realised that this machinery of RNA interference
works just as well in human cells. It's led to an explosion in interest,"
Professor Carmichael said.
Five years ago there were just a handful of scientific papers published
on RNAi, two years ago there were 100, last year there were 1,000 and
this year there will be thousands more, he said.
One idea for Aids treatment is to take out a person's blood cells and
engineer them using RNAi to make them immune to HIV. The patient
should then be resistant to infection.
The beauty of the process is that it is specific to the gene being targeted=
and so the interference should not result in the silencing of other
important genes, Professor Carmichael said. This is important when it
comes to possible side-effects. "If you design it against HIV then there is=
almost no possibility that it will result in a perfect match against the
patient's own DNA," he said.