Stem cells: the potential, the reality and the dangers

These are the questions being asked 22 years after Professor Irv Weissman and Dr Ann Tsukamoto discovered human blood stem cells in 1992. In that period they have experienced all of the joy and frustration of researching developing stem cell medicines.

Today they're trialling treatments for cancer and for degenerative diseases. But they're also deeply concerned about the over promising of stem cell medicine, and of the unproven treatments that cost desperate patients tens of thousands of dollars.

Prof Weissman leads the Stanford University Institute of Stem Cell Biology and Regenerative Medicine. His wife, Dr Tsukamoto, is Vice President of StemCells Inc. They are both convinced of the revolutionary potential of stem cell medicine to help us fight cancer and repair damaged organs, brains and limbs.

From research stage to the clinic

But they also know that much of today's stem cell research will never find its way to the clinic.

"Stem cell medicine is already making a difference through bone marrow transplants for cancer but there's too much excitement and too much hype and hope. Most of the clinical studies in the US are likely to fail because of the lack of rigorous science and understanding of the cells they're using," says Dr Tsukamoto.

And she's talking about highly credible research from leading institutions. There's even less evidence to support the stem cell treatments now being marketed to desperate patients in the US, India, China, and even here in Australia.

"Dangerous" cocktail of cells

"It's foolish and dangerous to inject a cocktail of cells and hope for the best," says Prof Weissman.

"Sadly many Americans can't enter real clinical trials because of the various dodgy treatments that have cost them hundreds of thousands of dollars.

"Before you sign up to a stem cell therapy ask: is the therapy backed by a credible research institution? Is the therapy approved by the FDA or the equivalent? Have the method and the results been published in peer-reviewed publications?" he says.

The role of regulations

"Regulations frustrate all of us. But they're there to protect us from unproven treatments."

So when will stem cell medicine deliver on its promise? "We need to refocus on pure stem cells, and how to harvest, grow and manufacture them."

"If we get that right then the real stem cell revolution will still be a decade or more away. But it will bring ways of repairing genetic disorders, organs and damaged brains," says Dr Tsukamoto.

In the interim there are promising developments in cancer. Prof Weissman and his colleagues at Stanford University have been assessing the one-off use of pure blood-forming stem cells in breast cancer and have seen four times the survival rate after 14 years. He's also found 'do not eat me' and 'do eat me' markers on a wide range of cancer cells and is about to start a clinical trial using those markers.

Cancer treatment vision

His vision of cancer treatment is first a treatment of chemo followed by a rescue with cancer-free stem cells that will ensure that the cancer cells are destroyed.  And Dr Tsukamoto's company is trialling human neural stem cells for brain and eye diseases and spinal cord repair. 

Prof Weissman and Dr Tsukamoto have been giving free public talks together with local experts in Sydney (25 August), Brisbane (26 August) and Adelaide (28 August), with a talk scheduled for Melbourne on 1 September.

They are touring as guests of the National Stem Cell Foundation of Australia, a charitable body that promotes the study and use of stem cells and public education.