- Stem Cells:A Status Report
Last October, during one of those periodic flurries of news that push the Stem Cell Wars back onto the front pages for a day or two, the telephone in the Harvard Medical School office of Dr. George Q. Daley kept ringing off the hook.
On one occasion, it was a reporter seeking Daley's assessment of a new technique for creating embryonic stem cells that had just been reported in the online edition of the journal Nature. Researchers in the laboratory of Rudolf Jaenisch at the Whitehead Institute in Cambridge, Massachusetts, had managed to clone a deliberately crippled mouse embryo, with the idea that if a genetically manipulated embryo lacked the ability to form a placenta and attach to the uterus, it would therefore lack the biological potential to become a mature creature. If the same trick worked with human embryos, Daley was asked, would this solve the ethical dilemma? He wasn't so sure. "The embryo that is established in the first few days," he pointed out, "is substantially normal."
Another reporter wanted to know what Daley thought about a second technique, also published in Nature, that sought to answer the ethical objections of stem cell critics. A team of researchers at Advanced Cell Technology in Worcester, Massachusetts, led by Robert Lanza, had found that at a very early stage of embryonic development, a single cell could be plucked away from an eight-cell embryo and used to derive mouse embryonic stem cells. Did this represent another alternative to the more "traditional" approaches to stem cell harvest, which require the destruction of human embryos and have thus aroused so much political and moral debate? Daley had his doubts about this one, too. The experiments, he said, "raise more questions than they answer."
And later that same week, researchers at Seoul National University in South Korea, led by Woo Suk Hwang, announced a plan to set up satellite labs in California and England to create, on order, cloned human embryos for the purpose of deriving customized stem cell lines. The Koreans, who had stunned the world in June 2005 with the report in Science that they had established eleven new human embryonic stem cell lines from cloned human embryos, now offered to franchise their expertise through a "World Stem Cell Hub." What did Daley think? "The details have yet to be divulged," he told the Wall Street Journal, "and the devil's in the details." (The details later became very devilish: soon thereafter Hwang withdrew from the initiative following reports of ethical improprieties in the group's egg harvesting program, and subsequently withdrew the Science paper amid allegations that some of the results were fraudulent.)
Having just set up a new stem cell laboratory at Children's Hospital in Boston, nothing would please Daley more than to devote all his time, energy, and expertise to [End Page 16] the biology of blood-forming stem cells. But the continuing ethical controversy, superimposed on the considerable scientific challenges of making advances in the basic research, has left Daley, like many stem cell researchers in the United States, caught in a pattern of occluded political weather that impedes their work. More than four years after President George W. Bush announced a policy that restricted federal funding for embryonic stem cell research, scientists like Daley have been forced to create new laboratories from scratch to pursue research with "nonpresidential" stem cell lines, tap private sources of financial support, provide a Greek chorus of commentary to journalists on every tangential new development, and routinely travel to Washington to testify before lawmakers who have annually threatened but to date failed to legislate any changes in national policy. It has all added up to distraction and, most important, delay.
In 2002, Daley and Jaenisch published a significant advance in which they used mouse embryonic stem cells, obtained by cloning—technically, "somatic cell nuclear transfer"—to partially restore immune function in immune-deficient mice. "It's now three years later," Daley lamented, "and I am still struggling to gain regulatory approval through our institution to be able to do those experiments with human material. And the increased sensitivity around...