Cow makes human insulin
Good news for insulin-dependent diabetics.
Argentine scientists have successfully produce a transgenic cow that carries in its chromosomes the human gene of insulin. According to the experts, this achievement could result in lower prices of human insulin, currently being produced from goat by only two pharma companies worldwide. Bio-Sidus, the biotechnology company based in Argentina is a pioneer in this kind of technology in South America.
The fact of been able to produce insulin from cows is a great advantage compared to the same in goats since it will allow significant increase in the production of insulin and will result in better prices for the consumers. As an example, Argentina currently imports about 200 kilograms (450 pounds) of human insulin to cover the local market every year. The Ministry of Public Health estimates that a ‘rodeo’ of 25 cows would be enough to satisfy the local demand and will result in huge savings from royalties and duties that are currently charged.
The first transgenic cow was named “Patagonia” and until the moment three more were born. Bio-Sidus staff consider that commercial production will begin in about ten months.
How can regular cows be transformed into insulin factories? The principle is simple, but the details are not. The insulin is a protein, which means that there is a gene that contains the information that a cell needs to makes it. The technology consists of transferring the gene from one organism (in this case human) to the DNA of another organism (the cow), and if everything goes well, the cells of the ‘receptor’ organism will produce this protein. In addition to the technical challenges that habitually complicate these procedures, the insulin poses an additional problem. If all the cells of the cow produced human insulin, the consequences would be fatal for the animal. This problem was solved by two ways: the gene was placed in the cow’s genome in such a way that works only in the cells of the mammary gland, avoiding the production of human insulin in other organs and tissues. There is another complication, however. Many milk proteins can freely circulate into the bloodstream, so the human insulin would spread throughout the body. For this reason, the gene of human insulin was modified of such form that the protein produced in the mammary gland cannot work unless is subject to a treatment called proteolysis, which is carried out during processing and purification of the milk extracts.
