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2-Plants: Cures On the Cob



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TITLE:  Cures On the Cob
SOURCE: Time Magazine, USA, by Margot Roosevelt
        http://www.time.com/time/magazine/article/
        0,9171,1101030526-452804,00.html
DATE:   May 19, 2003

------------------ archive: http://www.gene.ch/genet.html ------------------


Cures On the Cob

Plants spiked with extra genes are being harvested for drugs. Could the
wrong ones land in our food?

The scraggly cornstalks sprouting from pots in Andy Hiatt's laboratory
don't look particularly unusual. But woven into their DNA is a tiny strip
of mankind: a human gene that codes for an antibody to a sexually
transmitted disease - genital herpes - that afflicts some 60 million
Americans. When the corn plants mature and produce kernels, Hiatt's
company, Epicyte Pharmaceutical of San Diego, hopes to turn them into a
topical gel for herpes.

And that's just for starters. Epicyte is one of a host of biotech
companies that have seized on the information in the map of the human
genome - a map that was officially declared complete last month - to
create all manner of plant-based pharmaceuticals. Researchers have
launched more than 300 trials of genetically engineered crops to produce
everything from fruit-based hepatitis vaccines to AIDS drugs grown in
tobacco leaves. They call this biopharming.

Critics - and there are many - have another name for it. They call it
Pharmageddon. Environmentalists are worried that the unnaturally combined
genes, when loosed upon the ecosphere, will spread like genetic kudzu.
Consumer advocates, who have never warmed to today's genetically modified
foods, fear that plant-grown drugs and industrial chemicals will end up
on their dinner tables. Hoping to head off a public revolt, the Federal
Government is putting the finishing touches on new regulations aimed at
reassuring the grocery industry that human-based crops will not
contaminate the food supply.

But the proposed rules are not satisfying the critics or slowing the
biopharmers. Open-air trials of pharmaceutical crops have taken place in
14 states, from Hawaii to Maryland. A Texas firm is selling a corn-bred
enzyme that stimulates insulin production in diabetics. Clinical trials
have begun for experimental crop-grown drugs to treat cystic fibrosis,
non-Hodgkin's lymphoma and hepatitis B. "Molecular farming represents the
pharmaceutical industry's best opportunity to strike a serious blow
against such global diseases as AIDS, Alzheimer's and cancer," says
Francois Arcand, president of the Conference on Plant-Made
Pharmaceuticals, held in Quebec City earlier this year.

What's driving this effort to morph fields into drug factories? In a
word: cost. In the past decade, the DNA revolution has spawned a
generation of drugs made from human antibodies, the proteins that white
blood cells use to defend the body against disease. Today such
"biologics" are cultivated in huge fermentation vats, often by
painstakingly planting cloned human cells in such unlikely breeding sites
as the ovary cells of Chinese hamsters. Building one of these
sophisticated biofactories can take as long as seven years and cost up to
$600 million.

Achieving the same results through biopharming - splicing antibodies into
the genetic fabric of plants, growing them in fields and extracting and
purifying them - could cut costs by half. "If you don't have to spend
half a billion, then more products can advance to the marketplace," says
Arizona State University researcher Charles Arntzen. The opportunities,
he points out, are not limited to human drugs. Arntzen foresees rich
markets for plant-grown vaccines to protect fish and poultry against
diseases now being treated - and in many cases overtreated - with
conventional antibiotics.

So far, more than two-thirds of plant-based medicines are being tested in
corn - a plant whose genetics is well understood. But the perils of using
food crops became clear last December when the U.S. Department of
Agriculture (USDA) ordered the incineration of 500,000 bushels of
soybeans in Aurora, Neb. The soybeans, from a plant used in everything
from baby food and margarine to ice cream, were inadvertently mixed in a
silo with corn that was genetically engineered by a Texas firm, ProdiGene
Inc., to produce a vaccine against pig diarrhea. "Drugs have side
effects," says Jean Halloran of the Consumers Union. "They should not
turn up in our cornflakes."

The pig-diarrhea incident rattled the industry. Some major players, among
them Dow and Monsanto, are steering clear of the Farm Belt, preferring to
grow their pharmacorn in isolated areas of Arizona, California and
Washington State. Even so, the USDA - under pressure from Midwestern
politicians who dream of biopharm Silicon Valleys in Iowa - has stopped
short of restricting biopharming in major corn-growing states. Its new
rules would step up inspections of biopharms and expand the buffer zone
between genetically modified corn and food crops to a mile. But opponents
say that's not wide enough to prevent cross-pollination, and a coalition
of 11 environmental groups is filing suit against the Agriculture
Department. They want to ban the use of food crops for pharmaceutical
uses and restrict the plants to greenhouses. If such measures were
enforced, argues Jonathan McIntyre, chief scientist for Monsanto Protein
Technologies, "it would set back the industry 12 to 20 years."

At Epicyte's spotless laboratory, Hiatt is taking no chances. Tiny
tobacco leaves injected with herpes-antibody genes fill the incubators -
a backup, he says, in case corn is outlawed. And the company is branching
out, developing plant-grown antibodies to fight respiratory syncytial
virus, treat Alzheimer's, battle weaponized Ebola and even attack sperm -
a kind of biopharm birth control.

By the end of the decade, biopharmaceuticals are projected to grow into a
$20 billion industry. But how many of the new drugs will be manufactured
in living plant-factories remains uncertain. "There has been an emotional
response to the technology," says Hiatt. "But if we can bring down the
cost of treating these diseases, the drawbacks compared with the benefits
will be minuscule."


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