Is therapeutic cloning obsolete?

Next week the international grandees of therapeutic cloning gather in Cairns, Australia, the sun-soaked gateway to the Great Barrier Reef, for their annual conference. They have serious strategic issues to deal with along with their scientific papers and posters: persuading governments to open their wallets, ensuring that the Bush Administrations restrictions on their work are lifted, allaying the public's qualms about creating embryos solely for research.

But one issue will dominate: ten years after Dolly the sheep was cloned, is therapeutic cloning ready to be mothballed?

Only a few days ago an article in the leading journal Nature brought amazing news. (1) A Japanese team at Kyoto University has discovered how to reprogram skin cells so that they "dedifferentiate" into the equivalent of an embryonic stem cell. From this they can be morphed, theoretically, into any cell in the body, a property called pluripotency. It could be the Holy Grail of stem cell science: a technique which is both feasible and ethical.

"Neither eggs nor embryos are necessary. I've never worked with either," says Shinya Yamanaka. (2) The first instalment of his research appeared a year ago -- and was greeted with polite scepticism by his colleagues. At the time they were mesmerised by  dreams of cloning embryos and dissecting them for their stem cells.

The previous head of the International Society for Stem Cell Research, Lawrence S. B. Goldstein, had even dismissed reprogramming as quixotic. "If there are scientists who morally oppose [embryonic] stem cell research and want to devote their energies to uncovering alternatives, that’s fine," said Goldstein. "But in no way, shape, or form should we ask the scientific community and patient community to wait to see if these new alternatives will work." (3) Now, however, ten years after Dolly, not one scientist anywhere using a cloned human embryo has created a stem cell line. Not one. And a Japanese Don Quixote has.

This is mainstream research, not an eccentric theory from wild-eyed pro-lifers. Yamanaka's work has been confirmed by two other teams affiliated with the Massachusetts Institute of Technology, Harvard University and the University of California, Los Angeles -- both of them headed by ardent supporters of embryonic stem cell research.

They say that the reprogrammed cells meet all the tests of pluripotent cells -- they form colonies, propagate continuously and form cancerous growths called teratomas, as well as producing chimaeras. "Its unbelievable, just amazing," says Hans Schöler, a German stem cell expert. "For me, it's like Dolly. It's that type of an accomplishment." (4)

What Yamanaka did was to take a mouse skin cell and introduce into it four proteins which trigger the expression of other genes to make it pluripotent. "It's easy. There's no trick, no magic," he says. Naturally, it's easy only for experts at the moment. There are some worrying issues to contend with: one of the proteins seems to contribute to cancers in 20% of the mice. But since cancers are the Number One problem with embryonic stem cells as well, it is not surprising that stem cells induced to an embryonic-like state share this embryonic flaw.

Harvard researcher Chad Cowan says that it will change the field: "The most amazing thing about these papers is you now take this whole idea of reprogramming out of the hands of cloning specialists and put it into the hands of anyone who can do molecular and cell biology." (5)

Now the race is on to apply the technique to human cells. "We are working very hard -- day and night," says Yamanaka.

Will this disruptive technology open up ethical avenues in the promising field of stem cell research which do not involve turning women into battery hens for their eggs and destroying embryos?

At the moment, the stem cell grandees, like all establishment figures, have no plans to change their tune. One of the stars of Cairns, MIT's Rudolph Jaenisch, told Nature that therapeutic cloning remains "absolutely necessary".

And executives from embryonic stem cell companies were not optimistic about the new technique either. Because it involves tinkering with the genome, it could be dangerous, warned Thomas B. Okarma, of Geron, the leading private company in the field. Getting approval from regulatory authorities would therefore become far more complicated. (6) What else could he say? No doubt manufacturers of video tapes muttered about serious flaws in DVDs when they first appeared on the market.

With an ethical solution looking quite plausible, the pressure will be on scientists to justify embryonic stem cell research. Two years ago, Dr Janet D. Rowley, an Australian working in the US who is an implacable foe of the Bush Administration's policy, dismissed ethical solutions. "We have extremely limited research dollars, and to use them to study these alternatives is wrong," she declared. "That money should be available for actual research." (7) But now stem cells derived from embryos are starting to look like dead-end "alternatives".

Don't expect supporters of embryonic stem cell research to respond rationally, not in the short term, at least. The other day, Democratic Caucus Chairman Rahm Emanuel told the US House of Representatives as he voted to overturn the Bush policy: "It is ironic that every time we vote on this legislation, all of a sudden there is a major scientific discovery that basically says, 'You don't have to do [embryonic] stem cell research.' " (8)

Connect the dots, Mr Emanuel. Maybe you don't have to.

Michael Cook is editor of MercatorNet.


(1) "Simple switch turns cells embryonic". NewsNature. 7 June 2007.

(2) "Simple switch turns cells embryonic". NewsNature. 7 June 2007.

(3) "Scenarios for stem cell creation debated". JAMA. 22/29 June 2005.

(4) "Simple switch turns cells embryonic". NewsNature. 7 June 2007.

(5) "Teams Reprogram Differentiated Cells -- Without Eggs." Science. 8 June 2007.

(6) "A Long, Uncertain Path for New Cell Technique." New York Times, 7 June 2007.

(7) "Scenarios for stem cell creation debated". JAMA. 22/29 June 2005.

(8)  "Darn Cells. Dividing Yet Again!" Washington Post. 10 June 2007


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