genes have been manipulated could play a critical role in
developing new medications and cheaper treatments for human
ailments, scientists said Monday.
However, the use
of transgenic animals, which have foreign DNA integrated
into their genetic information, remains controversial and
faces regulatory, economic, and societal challenges.
the advantages and the challenges that accompany the new
technology ''is the key to public understanding,'' according
to a paper from the Council for Agricultural Science
and Technology. The Ames, Iowa-based
international consortium of 38 scientific and professional
societies assembles and interprets scientific information
for policymakers, regulators, lawmakers, media, and
the public and private sectors.
Carol L. Keefer,
associate professor of embryology and biotechnology at
the University of Maryland, is chairwoman of a CAST task
force that released a paper on Monday titled ''The
Role of Transgenic Livestock in the Treatment of Human
Disease.'' It's part of a series on how biotechnology
is being used in animal agriculture.
transgenic animals can be used to produce proteins and
antibodies in their blood and milk, or the animals can be
used as subjects to better study human diseases.
can provide significant advances in the development of
new treatments,'' she said.
Critics of the
new technology range from health professionals who worry
over its safety to members of animal welfare groups who say
it further exploits livestock.
a vice president of People for the Ethical Treatment of
Animals, called the technology ''Frankenstein science'' that
leads to the death of many laboratory animals. He said
there can be terrifying consequences for humans if
diseases cross species barriers.
science to expose humans and animals to a litany of
potential side effects,'' he said. ''Genetic engineering
like this is playing Russian roulette with the
building blocks of life, and sooner or later we're
bound to hit the loaded chamber.''
The paper stated
that none of the biopharmaceuticals in development have
completed all of the U.S. regulatory hurdles, although some
have progressed through preclinical and clinical
trials. It calls for further studies ''to establish
the safety and efficacy of biopharmaceuticals produced
using transgenic animals.''
scientists have worked mostly with transgenic cows, pigs,
and goats, Keefer said. Pigs especially have been used
as models to study heart disease, organ
transplantation, and eye disease, while the milk from
cows and goats has been a major source for
The paper said
transgenic animals are being engineered to produce human
antibodies that scientists hope can be used to treat
infections, cancer, and autoimmune diseases. Others
genes are being tweaked to create proteins that would
usually have to be harvested from human blood. The
paper says that can combat challenges the human blood supply
faces, such as shortages and the transmission of HIV.
genetically engineered animals as production systems for
human biopharmaceutical and blood products has great
potential for biomedical applications with regard to
these limitations,'' the paper said.
It also can be a
cheaper method to harvest the products and can provide
agriculture companies significantly higher prices than
traditional animal products, the paper said. While the
technology is promising, the CAST paper notes the
''It is apparent
that unless a biopharmaceutical produced by transgenic
animals offers clear and significant advantages compared
with more conventional products or procedures, it is
unlikely to receive regulatory approval or attain
commercial viability,'' the paper said.
It said using
management practices such at those now in place for meat
and milk production systems could help with acceptance of
the new technology.
continue to perfect technologies in the near future, more
applications of transgenic animals for the treatment of
human diseases will become available,'' according to a
statement from John Bonner, CAST's executive vice
president. (Amy Lorentzen, AP)