James Thomson plans to stay in Madison to study genesis of stem cells

James Thomson plans to stay in Madison to study genesis of stem cells

Professor James Thomson studies stem cells in his Primate Center lab. Photo courtesy of the University of Wisconsin-Madison.

Madison, Wis.James Thomson avoided talking politics in a public lecture on the eve of the presidential election, explaining instead the science behind his research into stem cells.
Thomson, a scientific celebrity on the University of Wisconsin-Madison campus since his 1998 feat of isolating human embryonic stem cells, packed an auditorium in the basement of the Biochemistry building.
Afterward, he said he wished stem cells had not become a campaign issue. “It’s unfortunate that it’s become so politicized,” he said, because whichever way the election goes, people’s opinions are sharply divided.

He also said California’s Proposition 71, which could put $3 billion of bond money into stem-cell research in the state, scared him. It could draw talent away from Wisconsin and other place. But Thomson plans to stay in Wisconsin for now despite the lure of sizable funding, he said.
His talk on Monday explored a fundamental but enduring question: What is a stem cell?

Back to basics

Leaving specific uses of stem cells to other researchers, Thomson’s lab is now focusing on the origins of embryonic stem cells, and on what kind of cells they actually are. The possibility he presented Monday was that they are germ cells, in the same class as the sperm and the egg. To find out, scientists are using a variety of markers to compare stem cells with other types and find similarities.
What they are also finding is that stem cells behave in some strange ways. For example, they don’t die easily. Viable embryonic stem cells have high levels of Caspase 3/7, enzymes that break down proteins as part of a process called programmed cell death, in which unneeded cells are culled during normal development of the body. Yet the stem cells do not die, Thomson said, even though the Caspase levels would kill most other cells. The reason is unknown.
Once embryonic stem cells are derived in the lab and cultured, they are no longer quite like the original cells of the embryo.
Normally, the embryo’s cells go on to become all the different cells of the body. And stem cells cultured in the lab can theoretically be induced to become all those types of cells. That’s what gives them their medical potential — they could one day be used to replace damaged tissue. But left in culture, embryonic stem cells will just continue to divide and produce more of themselves.
“They will divide, as far as we know, forever … naturally immortal,” Thomson said.
The means of creating the cultures in the first place has caused the political controversy over the research. Embryonic stem cells come from embryos, which are destroyed in the process. Proponents respond that the embryos, which come from fertility clinics, would be destroyed anyway as they are no longer needed for implantation.
An audience member asked whether stem cells could be derived while leaving embryos with enough cells to be viable. Thomson said they could, but the practice would be more ethically problematic than taking cells from embryos that would be destroyed anyway. “You are not benefitting the child,” he said.

The golden-state lure

This election year, stem cells have influenced far more than the presidential race. Just ask the Californians, who will vote November 2 on whether the state should sell $3 billion in bonds to fund stem-cell research.

Ever since President Bush forbade research using federal money on embryonic stem-cell cultures created after August 9, 2001, scientists have made few with a handful of existing cultures. The WiCell institute, where Thomson is scientific director, owns six. And though stem cells can theoretically keep growing forever, those cultures were made using old techniques that led to impurities.
California’s proposition could revitalize the field. But Thomson said having the money available only in one state would eliminate beneficial competition, and that the major funding should be federal.
“How are we going to compete with $3 billion?” he said.
But he added, “It’ll be $3 billion spent badly,” explaining that he thinks California will take time to learn how to distribute the money effectively.
The proposition has also raised concerns that good scientists from Wisconsin and other states could be drawn away to California by the promise of substantial funding. Thomson said there were factors other than money keeping him in Madison, but the lure of funding could prove significant for people hoping to make their careers.
“I would be mostly worried about post-docs and graduates,” he said.
November 2 will be a day of choice over stem cells, with President Bush planning to maintain the existing limitations to prevent more embryos being destroyed, and challenger John Kerry promising to federally fund the research so its potential can be explored. Stem-cell research, like stem cells, does not yet know its fate.
Jason Stitt is WTN’s associate editor and can be reached at jason@wistechnology.com.