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Cell scientists hope to grow human spare parts

Cells at lab
Scientists caution that a lot more research must be done before it might be possible to have a warehouse of human repair parts, grown to order in a petri dish  
CNN's Don Knapp reports on an idea that could revolutionize medicine.
Windows Media 28K 80K

May 22, 1999
Web posted at: 11:19 p.m. EDT (0319 GMT)

In this story:

Complex process

Cloned sheep Dolly plays a part


From Correspondent Don Knapp

MENLO PARK, California (CNN) -- A small biotech firm in California is working on a project that could profoundly change medical treatment by offering patients customized parts to repair damaged organs.

The Geron Corporation has developed a technology called "telomerase expression," which it says allows cells to keep replicating.

"These are probably some of the rarest cells in the world," said biologist Joe Gold, holding what may be immortality in his hands -- human cells that seem to keep dividing and growing indefinitely.

"These human stem cells have only existed for about a year or so now," he said.

Stem cells are capable of becoming almost any cell in the body and Geron has patented a process for harvesting and developing them.

With the two technologies, Geron researchers say they will be able to grow new human tissue capable of repairing heart muscle, bones, nerves, skin and eyes.

Complex process

But whether it can work remains a critical question.

"Time is the issue, and how complicated it is to make the organ grow," said Dr. Mary Lake Polan of Stanford Medical Center.

"And you also have to make the organ stop growing, or make the cell stop growing, because you don't want unrestrained growth. And I think learning to really control these processes will be complex," she said.

Geron scientists begin with cells from a human egg, fertilized by a sperm, in a laboratory at the University of Wisconsin.

After the cells grow and divide for several days, scientists harvest the stem cells that can become specialized.

"What developmental biology will tell us is that changing the environment for these cells will give them the direction to become specific types of cells," explained cell biologist Melissa Carpenter.

Cloned sheep Dolly plays a part

The human cell research project is borrowing some of the cloning technology that was used to create Dolly the sheep  

Before the tissue could be used to repair human organs, Geron had to find a way to reduce the risk of rejection.

To help find answers, the company turned to a famous sheep across the Atlantic. Earlier this month, Geron bought Roslin Bio-Med, the company formed by the Scottish scientists who cloned Dolly the sheep.

"The Roslin Institute, in the case of Dolly, has figured out how to make genetically identical animals," said Geron's Ronald Eastman. "We look to use that technology to create genetically identical cells."

Using Dolly cloning technology, Geron plans to remove the DNA from the specially prepared cells, and insert the DNA of the patient. Company researchers think the procedure will make the new tissue genetically identical to that of the patient, and eliminate the rejection problem.

Yet years of research and development lie ahead, the company cautioned, before patients might tap into warehouses of human repair parts.

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Geron Corporation
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