Cancer, other ways to cure are possible
Cancer Cure Now ! | 19.01.2007 15:18
A flock of designer hens, genetically modified with human genes to lay eggs capable of producing drugs that fight cancer and other life-threatening diseases, has been created by British scientists.
Researchers at the Roslin Institute near Edinburgh, which created pioneering GM animal "drug factories" such as Tracy the sheep as well as Dolly the clone, have bred a 500-strong flock of ISA Browns. These are a prolific egg laying French cross between Rhode Island Red and Rhode Island White chickens.
A ‘transgenic’ hen delivers an egg containing drug therapies at a fraction of normal cost
Because they make proteins used as drugs in the whites of their eggs, they offer the prospect of mass-producing at a fraction of the price drugs that cost thousands of pounds a year per patient. This marks an important advance in the use of farm animals for the production of pharmaceuticals.
Existing methods for producing protein drugs, such as monoclonal antibodies used to treat cancer and arthritis, are expensive and time-consuming.
Using GM — "transgenic" — farm animals for the mass production of such drugs is potentially cheaper, faster, and more efficient than standard methods, but researchers so far have been unable to make "pharming" workable.
The GM chickens are reported today in the Proceedings of the National Academy of Sciences by Dr Helen Sang and colleagues in the Roslin Institute and the companies Oxford Biomedica, which specialises in gene therapy, and Viragen, which is commercialising the technology.
They describe how they have produced transgenic hens by using a particular virus — an equine infectious anemia lentivirus — to insert the genes for desired pharmaceutical proteins into the hen's gene for ovalbumin. This is a protein that makes up 54 per cent of egg whites, around 2.2 grams for each egg — a massive amount by the standards of biotechnology.
They inserted the human genes into chicken embryonic stem cells, then blended those cells with those of a normal chicken embryo to create a chimera, a blend of GM and normal cells.
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Crucially, the cells in the oviduct (which lays eggs) consisted of GM cells and so passed on the implanted gene so the egg could make the drug protein.
The working proteins in these hens included miR24, a monoclonal antibody with potential for treating malignant melanoma, and human interferon b-1a, an antiviral drug.
Just as important, the genes were passed on to the next generation.
Although there have been attempts to make protein drugs in the milk of sheep, goats, cattle and rabbits, the team believes that the conversion of chickens into "bioreactors" offers many advantages. They produce more quickly and are much cheaper to look after.
"This is potentially a very powerful new way to produce specialised drugs," said Dr Karen Jervis of Viragen Scotland, which worked with the Roslin team.
"We have bred five generations of chickens so far and they all keep producing high concentrations of pharmaceuticals."
Andrew Wood, of Oxford BioMedica, whose researchers collaborated on the project, said: "This could lead to treatments for Parkinson's disease, diabetes and a range of cancers."
Researchers at the Roslin Institute near Edinburgh, which created pioneering GM animal "drug factories" such as Tracy the sheep as well as Dolly the clone, have bred a 500-strong flock of ISA Browns. These are a prolific egg laying French cross between Rhode Island Red and Rhode Island White chickens.
A ‘transgenic’ hen delivers an egg containing drug therapies at a fraction of normal cost
Because they make proteins used as drugs in the whites of their eggs, they offer the prospect of mass-producing at a fraction of the price drugs that cost thousands of pounds a year per patient. This marks an important advance in the use of farm animals for the production of pharmaceuticals.
Existing methods for producing protein drugs, such as monoclonal antibodies used to treat cancer and arthritis, are expensive and time-consuming.
Using GM — "transgenic" — farm animals for the mass production of such drugs is potentially cheaper, faster, and more efficient than standard methods, but researchers so far have been unable to make "pharming" workable.
The GM chickens are reported today in the Proceedings of the National Academy of Sciences by Dr Helen Sang and colleagues in the Roslin Institute and the companies Oxford Biomedica, which specialises in gene therapy, and Viragen, which is commercialising the technology.
They describe how they have produced transgenic hens by using a particular virus — an equine infectious anemia lentivirus — to insert the genes for desired pharmaceutical proteins into the hen's gene for ovalbumin. This is a protein that makes up 54 per cent of egg whites, around 2.2 grams for each egg — a massive amount by the standards of biotechnology.
They inserted the human genes into chicken embryonic stem cells, then blended those cells with those of a normal chicken embryo to create a chimera, a blend of GM and normal cells.
advertisement
Crucially, the cells in the oviduct (which lays eggs) consisted of GM cells and so passed on the implanted gene so the egg could make the drug protein.
The working proteins in these hens included miR24, a monoclonal antibody with potential for treating malignant melanoma, and human interferon b-1a, an antiviral drug.
Just as important, the genes were passed on to the next generation.
Although there have been attempts to make protein drugs in the milk of sheep, goats, cattle and rabbits, the team believes that the conversion of chickens into "bioreactors" offers many advantages. They produce more quickly and are much cheaper to look after.
"This is potentially a very powerful new way to produce specialised drugs," said Dr Karen Jervis of Viragen Scotland, which worked with the Roslin team.
"We have bred five generations of chickens so far and they all keep producing high concentrations of pharmaceuticals."
Andrew Wood, of Oxford BioMedica, whose researchers collaborated on the project, said: "This could lead to treatments for Parkinson's disease, diabetes and a range of cancers."
Cancer Cure Now !