Monday, January 15, 2007

Drug hope in GM hens' eggs

The West Australian - Jan. 15, 2007

Scottish scientists have bred a flock of genetically modified chickens which they hope will lay eggs that can be used to produce cheap drugs to fight life-threatening diseases.

Researchers at the Roslin Institute have reportedly created chickens which produced complex human proteins in their eggs that could be extracted and developed into drugs to fight diseases including cancer and multiple sclerosis.

Researchers injected human genes into the hens' DNA to make the birds secrete human proteins in the whites of their eggs - chickens have previously been produced with altered DNA but their ability to make the important proteins usually disappeared within a generation or two.

The Roslin team reportedly bred five generations of chickens and all produced high concentrations of the pharmaceuticals.

WA Institute for Medical Research Professor David Ravine said the process could have huge economic potential for reducing the costs of creating pharmaceuticals. "While there appears to be no real benefits for scientists to use this process for research purposes, local biotechnology companies may well be interested in the development for the creation of drugs in a more cost-efficient manner," Professor Ravine said.

American biotechnology company Viragen collaborated with the institute on the project, which was designed to substitute chicken eggs for the expensive bioreactor vessels used to make protein-based drugs.

Australian Medical Association WA vice-president Richard Choong said it was not controversial to create drugs for humans using proteins from genetically modified chickens.

"Humans had been using animals as a source of medicine for years, so this should not raise ethical concerns," Dr Choong said. "Often there's an emotion attached to using a human gene but a human gene is like any other gene, it's a quoted sequence in the DNA strand used for certain proteins. If they can ensure the purity of the protein, I think it is fine." Dr Choong did not think the chickens would be changed significantly because researchers wanted to create only one protein at a time.

The Scottish scientists also created Dolly the cloned sheep and used similar techniques for the latest project.

Viragen said eggs had been used to make vaccines for more than 30 years. It said chicken proteins, unlike those from other modified animals, had very similar sugars to humans so patients were less likely to develop antibodies which neutralised the protein drugs' effects.