Rethink stem cells? Science already has

Rethink stem cells? Science already has
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First Published: Tue, Mar 10 2009. 11 42 PM IST

Making way: President Barack Obama signs an executive order on stem cells and a presidential memorandum on scientific integrity on Monday. Gerald Herbert / AP
Making way: President Barack Obama signs an executive order on stem cells and a presidential memorandum on scientific integrity on Monday. Gerald Herbert / AP
Updated: Tue, Mar 10 2009. 11 42 PM IST
With soaring oratory, US President Barack Obama on Monday removed a substantial practical nuisance that has long made life difficult for stem cell researchers.
Making way: President Barack Obama signs an executive order on stem cells and a presidential memorandum on scientific integrity on Monday. Gerald Herbert / AP
He freed biomedical researchers using federal money—a vast majority—to work on more than the small number of human embryonic stem cell lines that were established before 9 August, 2001.
In practical terms, federally financed researchers will now find it easier to do a particular category of stem cell experiments that, though still important, has been somewhat eclipsed by new advances.
Until now, to study unapproved stem cell lines, researchers had to set up separate, privately-financed labs and follow laborious accounting procedures to make sure not a cent of federal grant money was used on that research. No longer. The lifting of such requirements “is just a major boon for the research here and elsewhere”, said Arnold Kriegstein, a stem cell researcher at the University of California, San Francisco.
George Q. Daley, who studies blood diseases at Children’s Hospital in Boston, said he had derived 15 human embryonic stem cell lines using private money, and that for the first time he could now apply for grants from the National Institutes of Health (NIH) to study these cells. In the last eight years, his lab has moved from 90% NIH support to half NIH, half private financing. But private money is now drying up, he said, and new NIH support will be particularly welcome.
However, the president’s support of embryonic stem cell research comes at a time when many advances have been made with other sorts of stem cells. The Japanese biologist Shinya Yamanaka found in 2007 that adult cells could be reprogrammed to an embryonic state with surprising ease. This technology “may eventually eclipse the embryonic stem cell lines for therapeutic as well as diagnostics applications”, Kriegstein said. For researchers, reprogramming an adult cell can be much more convenient, and there have never been any restrictions on working with adult stem cells.
For therapy, far off as that is, treating patients with their own cells would avoid the problem of immune rejection.
Members of Congress and advocates for fighting diseases have long spoken of human embryonic stem cell research as if it were a sure avenue to quick cures for intractable afflictions. Scientists have not publicly objected to such high-flown hopes, which have helped fuel new sources of grant money like the $10 billion (Rs51,800 crore) initiative in California for stem cell research.
In private, however, many researchers have projected much more modest goals for embryonic stem cells. Their chief interest is to derive embryonic stem cell lines from patients with specific diseases, and by tracking the cells in the test tube to develop basic knowledge about how the disease develops.
Despite a Food and Drug Administration-approved safety test of embryonic stem cells in spinal cord injury that the Geron Corp. began in January, many scientists believe that putting stem cell-derived tissues into patients lies a long way off. Embryonic stem cells have their drawbacks. They cause tumours, and the adult cells derived from them may be rejected by the patient’s immune system. Furthermore, whatever disease process caused the patients’ tissue cells to die is likely to kill introduced cells as well. All these problems may be solvable, but so far none have been solved.
Restrictions on embryonic stem cell research originated with Congress, which, each year since 1996, has forbidden the use of federal financing for any experiment in which a human embryo is destroyed. This includes the derivation of human stem cell lines from surplus fertility clinic embryos, first achieved by James Thomson of the University of Wisconsin in 1998.
President Bill Clinton contemplated but never implemented a policy that would have allowed NIH-financed researchers to study human embryonic stem cells derived by others. Research was able to begin only in August 2001, when president George W. Bush, seeking a different way around the congressional restriction, said researchers could use any lines established before that date.
Critics said the distinction between the Clinton and Bush policies lacked moral significance, given that each was intended to get around the congressional ban, based on a religious and moral argument. The proposed Clinton policy amounted to: “Stealing is wrong, but it’s OK to use stolen property if someone else stole it.” The Bush policy was: “Stealing is wrong, but it’s OK to use stolen property if it was stolen before 9 August, 2001.”
Obama has put the proposed Clinton policy into effect, but congressional restrictions remain. Researchers are still forbidden to use federal financing to derive new human embryonic stem cell lines. They will, however, be allowed to do research on new stem cell lines grown in a privately financed lab.
Stem cell research is the best known of several avenues of investigation into what is known as regenerative medicine. To regenerate the aging body with its own subtle repair systems, of which stem cells are one component, would be far more effective than the brute methods of drugs and surgery used today.
But scientists are still merely at the threshold of understanding how the body’s 200 different types of cell interact with one another. It seems likely to be years before biologists know all the settings that must be adjusted in a human cell’s chromosomes to make it become a well-behaved cone cell in the retina or a dopamine-making neuron of the type destroyed in Parkinson’s.
Despite the new interest in reprogrammed stem cells, human embryonic stem cells are still worth studying, both to track the earliest moments in disease and to help assess the behaviour of the reprogrammed cells.
©2009/THE NEW YORK TIMES
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First Published: Tue, Mar 10 2009. 11 42 PM IST