Tackling the question of what individual genes do 14/2/03. By the Public Health Genetics Unit A new project will use the technique of RNA interference (RNAi) to switch off the expression of one gene at a time in human cells and see how cellular function is affected.

The project involves scientists funded by Cancer Research UK and the Netherlands Cancer Institute in Amsterdam

The RNAi method works by targeting the messenger RNA produced when a gene is expressed in a cell: destroying the mRNA permanently silences the gene. The group aims to produce a 'library' of cell lines, each characterised by the silencing of one gene.

An initial pilot phase will target about 8000 genes; the hope is that if this is successful then cell lines silenced for each of the 35 000 genes in the full genome could be produced by mid-2004.

The cells will be available for use by researchers in the two funding organisations who want to explore the functions of individual genes. Researchers from other organisations will be able to purchase them. There are limits on how much can be learned about gene function from experiments in isolated cell lines, but continuing work using RNAi in nematode worms - whose gene function is remarkably similar to our own - will add to the picture.

Human cancer cells will also be used as targets for RNAi: the hope is that the method may identify genes that, when switched off in tumours, make them revert to a non-cancerous state. Such genes may be fruitful targets for new cancer treatments.

Article courtesy of the Public Health Genetics Unit .