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Is the End Coming for Embryonic Stem Cells?

By Michael Cook

Embryonic stem cell research is looking increasingly like a dead end as clinical trials are cancelled in favour of adult stem cells.

Remember the saying “ethics is playing catch-up with science”? It was one of the trusty clichés of Australian science journalists in the lead-up to a heated debate in Federal Parliament in 2005 over embryo research, therapeutic cloning and embryonic stem cells.

From a layman’s point of view, the nub of the issue was that adult stem cells were ethically acceptable but multipotent, while embryonic stem cells were ethically contentious but pluripotent. Why use a pen knife when you had a Swiss Army knife?

So much was at stake, not only here but in the US and Europe. In California, voters passed an amendment to the state’s constitution to fund research with human embryonic stem cells and to create the California Institute for Regenerative Medicine (CIRM). They knew that this was going to cost them at least US$3 billion, but it was worthwhile because these cells would lead to treatments for incurable and devastating diseases like cancer, diabetes, heart disease, Alzheimer’s, Parkinson’s, spinal cord injuries, blindness, HIV/AIDS, mental health disorders, multiple sclerosis and Huntington’s disease. When push came to shove, the ethics had to change.

At the time, the scientific case for allowing “therapeutic cloning” and research on human embryos was overwhelming. Many politicians and voters had qualms about the commodification of human life that this involved, but the medical potential was mind-boggling. The loss of a few human embryos seemed a small price to pay.

In effect, there was an implicit pact between the public and stem cell scientists: we’ll swallow our misgivings and provide the funding, you provide the cures.

But what happens when this pact falls apart? Unfortunately, this seems to be what is happening.

Embryonic stem cell research is looking increasingly like a dead end. In November, after many false starts and a year after launching a human trial for spinal cord injuries, the California-based biotechnology firm Geron pulled the plug on all of its embryonic stem cell research to focus on cancer drugs. It had to: it was going broke.

This was a significant moment. Geron was the leading company in embryonic stem cell research. It had been the focus of media attention for years. A cure for spinal cord injury would have been the ultimate vindication of human embryonic stem cell research.

But these hopes have crashed and burned. There have been no cures. The main development for therapeutic cloning since the Australian Parliament’s debate was a gigantic fraud by the Korean scientist Hwang Woo-suk. Nowadays there is only one other company conducting a clinical trial with human embryonic stem cells.

History seems to have passed this technique by. In 2007 a Japanese scientist, Shinya Yamanaka, published a technique for morphing ordinary skin cells into pluripotent cells. Most of the leaders in embryonic stem cell research jumped ship immediately because the new cells were both pluripotent and ethical. The CIRM now looks like a white elephant that cash-strapped Californians can hardly afford.

Is there any hope left after the hype? Yes, said New Scientist in its response to Geron’s failure, without a trace of irony: “Treatments based on adult stem cells are undoubtedly in the lead, with some very encouraging results this year… So at the moment, adult cells are leading the way clinically? Absolutely… In terms of sheer numbers and commercial potential, they are way in front.”

Five years ago, some scientists were ridiculed for saying this. They have been vindicated.

What about the pact? Like many other contributions to the debate, the Australian government’s Lockhart Report and a subsequent Senate Committee report make embarrassing reading nowadays. New ethical standards have been enshrined in Australian legislation, but the public has received nothing in return.

Will Nature, Science or the New England Journal of Medicine utter mea culpas for having demanded new ethical standards for dealing with human embryos? Perhaps they are hoping that no one will notice.

But is this the best attitude to keep faith with the public? The Bush Administration lost its credibility over non-existent weapons of mass destruction. Scientists risk something similar over medicines of mass therapeutics.

Michael Cook is editor of BioEdge, an internet newsletter about bioethics.