Growth Hormone

[~MaryO~]

http://story.news.yahoo.com/news?tm....ow_dc_1

 

Argentina Cow Clone Step Toward Cheaper Growth Drug

Fri Aug 16, 5:20 PM ET

By Matias A. Loewy

 

BUENOS AIRES (Reuters Health) - The Spanish-speaking world now has its first cloned calf: "Pampa," a female born in Argentina last week.

 

 

The 37-kilogram Jersey calf was delivered by C-section after 278 days gestation and a global investment of $2 million.

 

Scientists who conducted the project consider Pampa's birth a step in the development of cloned and genetically modified cows capable of producing "more affordable" human growth hormone (hGH) and other expensive medicines, they said this week at a press conference.

 

This requires inserting the human gene responsible for producing the hormone into an embryo, theoretically making it possible for the mature animal to produce hGH in its milk. The birth of four calves containing the gene is expected in September, Dr. Carlos Melo, research and development manager at Bio Sidus, the company directing the research, told Reuters Health. But it will be some time before they can produce the hormone, Melo added.

 

"Within 4 years we may have a (decent number) of cows producing daily several grams of hGH in their milk," Melo told Reuters Health.

 

HGH from milk might be as much as 90% cheaper than the hGH now available, Melo told Reuters Health. In Argentina alone, some 1,000 children with dwarfism take the hormone daily to foster normal growth.

 

Pampa's birth places Argentina among the nine countries in the world capable of cloning livestock. The cloning technique involves removing the nucleus from a bovine egg cell and replacing it with the nucleus of a fetal cell-skin fibroblast, previously obtained from the animal to be copied.

 

In order to get pharmaceutical products from the milk, scientists must insert the human gene of interest into the embryo before implanting it into a surrogate mother cow.

 

An adult Jersey cow produces around 10 liters of milk a day, at least 200 days in the year. Bio Sidus expects that every single cloned cow would eventually produce 2 kilograms of raw hGH each year.

 

Once hGH is collected in the milk, scientists will have to purify and formulate it as medicinal product. "The whole process might imply losing around 50% to 80% of the original amount of the protein," Melo said. The product is not expected to reach the market before 2008.

 

Bio Sidus is already producing recombinant hGH by conventional bacterial fermentation, but cloning technology might allow the company to dramatically increase its current level of production.

 

In the future, Bio Sidus also plans to apply the technology to produce human tissue plasminogen activator (tPA), a potent clot-dissolving drug used to treat heart attack and stroke.

 

Bio Sidus SA is the biotech branch of the pharmaceutical group Sidus, founded in Argentina in 1938. The company manufactures five recombinant proteins, such as erythropoietin and filgrastim, and exports around 70% of its production to almost 40 countries.