Grows genetically engineered tobacco plants Health Canada hopes to use in cancer treatment

By LEONARD ZEHR
Biotechnology Reported
Friday July 21, 2000

A small Saskatchewan biotechnology company has found a novel use for an abandoned copper mine in Michigan: growing tobacco plants that produce the building blocks of a life-saving drug for Health Canada.

Prairie Plant Systems Inc. will announce today the first-ever molecular farming project that is housed in a tunnel 91 metres underground at the former Copper Range Co. white Pine mine.

The tobacco plants have been genetically engineered by Health Canada so that their seeds will produce a new protein the agency hopes to develop as a treatment for bone marrow cancer.

"This has the potential to usher in a new era of mass production of biopharmaceuticals, especially ones that are expensive to make conventionally," said Zettl, president and chief executive officer of Prairie Plant.

Plants have been used for medicinal purposes for thousands of years, providing some of the most important drugs used in medicine, aspirin, morphine and the anti-cancer drug taxol. Recent advances in molecular genetics, however, have allowed researchers to insert human DNA into certain plants-such as tobacco, potato, corn and alfalfa-that have a natural ability to assemble genetic information into proteins at a fraction of the cost of traditional cell culture and fermentation system.

Today, analysts estimate that as much as 25 percent of all prescription drugs are derived from plants.

Mr. Zettl, who has been running Saskatoon-based Prairie Plant systems since 1990, said the company and investors in Michigan have formed a new joint venture Called SubTerra LLC to initially develop 3,000 square feet in the mine at a cost "well into the six figures."

"It looks like an ordinary lab, except it has jagged walls that are painted white," he said.

By the beginning of November, SubTerra expects to deliver "several Kilograms" of tobacco seeds to Health Canada scientists, who will grind the seeds to recover the protein for clinical testing.

Health Canada officials could not be reached for comment.

"We're not going to make money from a pilot project, but it's a stepping stone to a commercial venture," he said. Besides expanding the mine space in the future, he wants become a biopharmaceutical manufacturer.

Mr. Zettl said the advantages of underground farming include a secure containment area for genetically modified plants and a controlled environment, which promotes accelerated plant growth.

"We've also discovered a trigger that stimulates growth of any plant, but it hasn't been patented yet."

Prairie Plants is no stranger to underground farming. In 1991, the company created a growth chamber in an unused section of the Hudson Bay Mining and Smelting Co. Ltd. zinc-copper mine at Flin Flon, Manitoba, for research and development into cloning fruit trees.

The company, which sells a variety of trees for orchard development and also grows plants for mine reclamation, is expected to generate $1-million this year, he said.

In 1995, it began growing yew trees underground at Flin Flon under a contract to produce taxol, a drug used to treat breast cancer. "We had the trees growing about three feet a year, which is faster than the six inches or so that they grow in the wild," Mr. Zettl said.

The venture fell through because Prairie Plant's partner failed to obtain the Canadian marketing rights to sell the drug.