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Hens Lay Drug Laden Eggs

PostPosted: Fri Jan 26, 2007 11:01 pm
by vet
26 Jan, 2007: Cancer and other life-threatening diseases could be prevented by eggs especially laid by a breed of genetically modified chickens, a breakthrough that could cut the cost of mass-producing drugs and potentially save millions of pounds of the National Health Service (NHS), a team of British scientists reported yesterday.
Researchers at the Roslin Institute near Edinburgh, where Dolly the sheep was cloned in 1997, have created the world's first breed of chicken genetically altered to lay eggs with medicinal properties that can be used to make life-saving drugs.
These trans-genic chickens produce the cancer drugs in their egg whites, said the study that published in January 15th issue of the Proceedings of the National Academy of Sciences.
Helen Sang, the leader of the Roslin team, said they genetically modified a flock of 500 ISA browns, a French breed of chicken, which is a cross between Rhode Island Red and Rhode Island White chickens, and can produce up to 300 eggs a year.
The Roslin team added human genes to the DNA of ISA Brown hens, enabling them to produce complex medicinal proteins. These human proteins are secreted into the whites of the birds' eggs, from which they can be extracted to produce drugs for humans.
Working with the biotechnology firm Viragen and the British biotech company Oxford BioMedica, Dr Sang found that all the egg whites from the hens contained miR24, a monoclonal antibody with potential for treating malignant melanoma and arthritis, and human interferon b-1a, an immune system protein from a family of proteins that attacks tumors and viruses.
It is really hard to develop these complex drugs in the lab. "Many human therapeutic proteins, such as monoclonal antibodies, are produced in industrial bioreactors, but setting up such systems is both time-consuming and expensive," the study said.
The Roslin scientists said that using farm animals to produce drugs is potentially faster, cheaper and more efficient than current industrial methods.
The team said that in their latest study, they had bred five generations of hens and each one had produced good concentrations of drugs. Theoretically, the technique could be used with a wide range of genes so that hens could produce many different drugs for a range of diseases, from Parkinson's to diabetes and other types of cancer, the researchers added.
"This is potentially a very powerful new way to produce specialized drugs," said Dr Karen Jervis of Viragen Scotland, a biotech company working with Roslin. "We have bred five generations of chickens so far and they all keep producing high concentrations of pharmaceuticals."
The research has opened the door for creating a potentially limitless, inexpensive source of medicinal proteins, observers assert.
NHS also hopes that such technologies will help it to slash its annual bill for prescription drugs which was £8 billion last year; an increase of 46% since 2000.