GM chicken, new weapon in fight against cancer

British scientists have developed genetically modified hens capable of laying eggs containing proteins needed to make cancer-fighting drugs.

The breakthrough was the work of the Edinburgh-based Roslin Institute, the same research centre that created the cloned sheep Dolly, the BBC reported.

The work could lead to a range of drugs that are cheaper and easier to make, said the report. Professor Harry Griffin, director of the institute, told the BBC: "One of the characteristics of lots of medical treatments these days is that they're very expensive.

The idea of producing the proteins involved in treatments of flocks of laying hens means they can produce in bulk, they can produce cheaply and indeed, the raw material for this production system is quite literally chicken feed." Roslin has bred five generations of the modified birds.

Numbering 500 in all, their existence is the result of more than 15 years of work by Dr. Helan Sang, the lead researcher. But it could be another 10 years before a medicine is fully developed, the institute cautioned.

Therapeutic (curative) proteins such as insulin have long been produced by bacteria, but there are some complex proteins that can be made only in the more sophisticated cells of larger organisms, said the BBC report.

Already, scientists have successfully produced a range of these molecules in the milk of genetically modified sheep, goats, cows and rabbits.

Now chickens have been added to the list of "biofactories". It is a fairly straightforward process to extract and purify the therapeutic proteins located in the egg whites, said the report.

Some of the birds lay eggs that contain MiR 24, a type of antibody with potential for treating malignant (harmful) melanoma, or skin cancer. Others produce human interferon b-1a, which can be used to stop viruses replicating in cells.

The Straits Times