Stem cell research: the big task ahead

In his closing comments to the National Stem Cell Centre conference in Melbourne earlier this month, Monash University's Martin Pera gave voice to a thought many of the scientists at the conference had been contemplating over the previous couple of days.

"What is in front of us is of the scale of the Human Genome Project, if not larger," Pera told delegates. "In the last five years the ethical frameworks have been established. But we have to continue the ethical debate."

Keynote speaker Prof Ron McKay, from the US National Institutes of Health National Institute of Neurological Disorders and Stroke, agreed with Pera. "We need to work together on a larger scale than we are at the moment," he said.

McKay is part of an international group of stem cell scientists who are trying to standardise the growth conditions, reagents and protocols used by stem cell researchers so that experiments can be more readily repeated.

One thing that stem cell researchers can't agree on is when to go into the clinic with potential therapeutic treatments derived from stem cells or stem cell research. McKay is firmly of the opinion that earlier is not better than later, and much more information is needed about the function of stem cells in vivo before clinical studies are attempted.

"You have to know your cells. You have to know how well your cells function if you are really serious about treatment of disease," he said. "You need to have a very clear idea, a model of the function or mechanism... it's a lot of work to do but at the end of it you will know a lot more about the disease.

"It's tremendously important that we focus on both sides of the thing and insist we don't just get a magic solution without understanding."

McKay's own research focuses on differentiation of embryonic stem cells into functioning neurons that could potentially be used to treat neurodegenerative disorders like Parkinson's disease. But he said it was still unclear how the cells differentiated and developed.

"Ideally I would like to see a pretty good model of how neurons work, their development and function before using stem cell derived neurons in the clinic," McKay said.

One researcher who agreed with him was the Netherlands' Prof Christine Mummery, whose lab studies cardiac cell differentiation. Earlier this year, it was the first to demonstrate beating cardiac cells derived from human embryonic stem cells, and now it is investigating how similar these cells are to mature cardiomyocytes, and whether they can be coupled together.

Mummery said the potential to cause irreversible changes that could permanently harm patients by using stem cells was a risk that should not be ignored. The death of a patient due to administration of stem cells would set the field back, she said.

But other scientists believe that while it is crucial to know exactly what was being given to a patient, the exact mechanism of action was not always critical information.

"When it comes to clinical applications, we have to have a clear idea of what we're giving the patient, and of safety and tolerability. But we don't need to necessarily know how it works," said Monash's Pera.

Mummery said her exposure to ethics as a result of her involvement in the efforts to get appropriate legislature and frameworks up and running in the Netherlands had given her a changed perspective on ethics in general, not just with regard to embryonic stem cells.

"It's important to realise that not only science evolves, but ethics evolves too -- the ethical point of view of society develops," she said. "The next ethical risk group is patients, not embryos."

International visitors to the conference were also interested in Australia's National Stem Cell Centre. "The principle of having a national stem cell centre is very forward thinking of the Australian government -- it's very sensible to compare adult and embryonic stem cells," said Mummery. "But I hope they don't want rewards too quickly."

McKay took a broader view on stem cell research generally. "We need to have a very effective government-funded [research] domain that interacts very effectively with the private sector at a defined point to commercialise [the research]," he said.

McKay said one of the reasons that Australian stem cell researchers were so important was that they had a clear vision of how to use the technology.