Fact Sheet: There is no proof of concept that embryonic stem cells can cure the many diseases claimed
8 October 2002

There is no scientific 'proof of concept' that stem cells derived by destroying human embryos can cure all the conditions that have been cited in debate ie. Alzheimer's, Diabetes, Parkinson's, Motor Neurone Disease, Spinal Cord Paralysis, MS and Muscular Dystrophies.

Professor Colin Masters

"I am the Professor of Pathology at the University of Melbourne and my expertise is limited to the study of brain diseases, Alzheimer's and other neurodegenerative disorders in particular. My observations on the current stem cell debate relate to the misrepresentation which has occurred over the potential therapeutic benefits of stem cell therapies, especially in the areas of Alzheimer's disease, Parkinson's disease, motor neuron diseases and other causes (traumatic and non-traumatic) of spinal cord paralysis. I have been concerned that advocates of embryonic stem cells as a therapy have created false expectations in the mind of the general community." (Professor Colin Masters, Department of Pathology, University of Melbourne, submission 87)

Professor Michael Pender

"In proper medical research, 'proof of concept' must first be established in animal models before moving to human subjects. Such proof using embryonic stem cells has not been established in any of the conditions such as Alzheimer's, multiple sclerosis, diabetes and Parkinson's disease, which are so often part of public discussion. Some of the proposed cures are highly unlikely and others are only potentially viable on a very long time-frame. For example, Alzheimers disease is a global disorder of the brain and is highly unlikely to be amenable to any form of cell therapy at any time in the future." (Professor Michael Pender, Director, Neuroimmunology Research Unit , University of Queensland, submission 84).

Professor Peter Silburn

I would also like to talk about the view of Parkinson's Australia. Why Parkinson's disease? Look at all the business about stem cell research-people claim that it will cure Parkinson's disease. That is nonsense. The reason it is nonsense is this: we have information that placing dopamine neurgic cells in the brain can help the motor symptoms of Parkinson's disease. There is evidence for that. There is no evidence that embryonic stem cells will do that. In fact, one in five turned into Teredo carcinoma, a form of cancer. (Professor Peter Silburn, Spokesperson, Scientific Committee Parkinson's Australia, Princess Alexandra Hospital, and Parkinson's Australia. Committee Hansard, 17 September 2002, page CA53)

Professor Peter Rowe

"I have an interest in a number of these things that are thrown around in the press, particularly things like Alzheimer's, diabetes and Parkinson's. These are very complex disorders. To say that you will cure them by putting in a few cells is a joke. We do not even know the genetic basis. We know that there are environmental factors. We know that Alzheimer's is a global disease; what are you going to do-replace the brain? So we are looking at a very simplistic approach here to treat people.

"It is not even sure that Parkinson's disease is primarily caused by specific self-generated damage within the particular part of the brain which is responsible for producing the symptoms. It may well arise from a systemic disorder, and work has been done to suggest that that is the case. In which case, you put cells in and you get the same process occurring again. There is a genetic basis to many of these conditions. If you go putting in cells derived from whatever source you might think, they are going to be subject to exactly the same processes, so you have problems on your hands there." (Professor Peter Rowe, Director, Children's Medical Research Institute, Westmead, Sydney. Committee Hansard, 19 September 2002, page CA95).

Professor Michael Good

"ES cells and derived tissue have a huge proliferative potential, which is a disadvantage, not an advantage as argued by some. ES cells commonly form teratocarcinomas - tumours that express multiple tissue types. In a paper recently published by Bjorklund et al, where ES-derived cells were used to treat mice with a Parkinsons -like disease, 5 animals from 19 with grafts were euthanased because of 'sickness before the endpoint of the study. (The) animals had developed teratoma-like structures at the implantation site'.

"I am not aware of any good animal data showing that diseases such as diabetes, MS, Alzheimers etc can be cured by ES-derived tissue. It is most unusual in medical research to be rushing to human studies with very poor preclinical data."
(Professor Michael F. Good, Director, Queensland Institute of Medical Research, submission 614)

Professor John Martin

"... proponents argue that that work on HES [human embryonic stem] cells is absolutely essential and urgent in order to discover new treatments for previously untreatable chronic diseases. Those commonly put forward are Alzheimer's, Parkinson's, diabetes, muscular dystrophies, the replacement of dead heart muscle following heart attacks, and of brain tissue following strokes,etc.

"There is no supporting evidence for such claims, with some of these cures highly unlikely, and others on a very long time-frame. Alzheimer's is a global condition of the brain and its causes are unknown. It is featured by insoluble accumulations of b-amyloid peptide and then aggregates of fibrils. It is virtually impossible to conceive that any form of cell therapy could be helpful with Alzheimer's disease. Exactly the same can be said of motor neuron disease, which is a diffuse disease throughout the spinal cord. In experimental models of Parkinson's disease in rodents, some short-term improvements have been obtained, but no lasting benefits, and the risk of ES-related tumour development still present ( e.g. in L. Bjorklund et al, Embryonic stem cells develop into functional dopaminergic neurons after transplantation in a Parkinsonian rat model, Proc Natl Acad Sci USA 999:2344, 2002). Similarly, in experimental models of diabetes, with chemical destruction of the insulin-producing cells of the pancreas, short-term benefit has been obtained with ES cells, again with the tumour risk.

"In all branches of medicine it is mandatory that 'proof of concept' is obtained through extensive preclinical experimentation in animal research before human studies are performed. Not in the case of even one of the diseases so commonly invoked, has there been such proof of concept obtained, and it is abundantly clear that much more animal experimentation must be carried out , even to establish in the first instance that any human clinical trial would have any chance of success. It must be emphasised that there can be no justifiable purpose in human ES cell research unless extensive animal experimentation establishes the validity of this approach."
(Professor T John Martin AO, Emeritus Professor of Medicine, University of Melbourne, submission 162)