Stanford Report, November 8, 2006

Science of stem cells and aging highlighted at Wonderfest fair

BY BRIAN D. LEE

Stem cells cannot save us from death, but they might help us live longer and healthier lives—provided the government doesn't interfere, researchers said Nov. 4 at the Wonderfest science fair at Stanford.

For nine years, Wonderfest has provided the public with an opportunity to ask Bay Area scientists questions about a wide range of subjects, from biomedicine to astrophysics. The two-day event, dedicated to the late astronomer Carl Sagan, was held at Stanford and the University of California-Berkeley. This year's gathering fielded such topics as whether the world is made of strings, can love be understood, was the origin of life inevitable and can we arrest human aging.

"There is a lot of evidence that maximum lifespan can be extended," said Thomas Rando, associate professor of neurology and neurological sciences at Stanford, noting that the increase in life expectancy over the last few centuries gives reason to remain hopeful. "Historically, there has been a huge change in how long we live."

To stop aging, we need to better understand what occurs with aging, Rando added. "What does it mean to die of old age?" he added.

Rando described aging as a progressive loss of tissue structure and function matched with a decline in tissue repair. "The older you are, the more likely you are to have general functional impairment," he said. "In an older person, bone fractures and tissue damage heal less quickly."

Rando, who investigates the regenerative properties of muscle stem cells, predicted that stem cell research would likely have a greater impact on health than longevity. "People think that stem cells can help us live to 150 or 200," he said. "But I am more convinced that the whole value of stem cells will be to help us age healthier than make us live longer."

Cancer and aging

Judith Campisi, senior staff scientist at Lawrence Berkeley National Laboratory, shared a more sobering perspective on human aging. "I really think that the theoretical and practical hard wall we are going to hit when we think about extending human lifespan is going to be the problem of cancer," she said.

Campisi called cancer an age-related disease that is inevitable. "If any of you live long enough, you will almost certainly get cancer, but you might not die of cancer," she said.

What should surprise us, according to Campisi, is that cancer does not happen at a younger age. "The real question is, why don't we get cancer more often than we do?" she said.

The answer turns out to play a role in the reason we age, she said, noting that cells that could become cancerous when young are told to stop dividing, and, over a lifetime, this collection of arrested cells creates an environment ripe for cancer. "The protective mechanisms that keep us from getting cancer when young can drive cancer in later life," she explained.

But according to Campisi, stem cells will not save us from cancer. "Stem cells are magnificent, because they can replenish tissues and help repair damaged tissues," she said. "On the other hand, stem cells divide, and dividing cells are at risk for becoming cancerous."

Berg honored

In an evening ceremony, Stanford Nobel laureate Paul Berg, the Robert W. and Vivian K. Cahill Professor of Cancer Research, Emeritus, was given the festival's Carl Sagan Prize for Science Popularization for his outspoken support of embryonic stem cell research. In accepting his award, Berg emphasized the importance of stem cells in cancer research. "Cloned human embryonic stem cells open a path to the discovery of a connection between genes and the predisposition to cancer," he said.

Berg shared the 1980 Nobel Prize in chemistry for his work on recombinant DNA. At the time of his early experiments, he said fear of biotechnology threatened the field and inspired him to become an advocate. "That near disaster, namely the Congress intervening and possibly prohibiting a new line of research, prompted me to take up the cause for advocacy for freedom of scientific research," he said.

The controversy over stem cell research is different, Berg noted. "Unlike the debate over recombinant DNA, which turned on whether or not the scientific investigations posed a threat to human health, the concern with human embryonic stem cells has more to do with values and ideology," he said.

Berg focused on the need for all critical thinkers to become involved in the stem cell debate. "This is not an issue, I believe, for stem cell biologists alone, but for all scientists," he said. "When science is attacked on ideological grounds, I believe its very integrity is threatened."

Brian D. Lee is a science-writing intern with the Stanford News Service.