MEDICAL SCIENCE: by Charles Francis, AM, QC, RFDNews Weekly
Cloning - dead as the Dodo?
, July 21, 2007
A scientific breakthrough in Japan will enable stem cells to be created without the need to clone and destroy human embryos, reports Charles Francis QC.A week is a long time in politics, but stem-cell science is moving even faster than politics. On June 7, the journals Nature and Cell Stem Cell published three papers reporting on a simple method of turning mouse skin cells into "pluripotent" stem cells which function like embryonic stem-cells in that they can be turned into any kind of cell.
These stem cells were obtained without cloning or destroying embryos and without the use of eggs or sperm.
Shinya Yamanaka of Kyoto University, who pioneered the technology, described his work at an international conference on stem-cell research held in Cairns in June.
"It's easy, there's no magic," he said. He took a mouse skin cell and introduced four small proteins which reprogrammed the cell's nuclear DNA to make it pluripotent, like embryonic stem-cells. "Pluripotent" cells have the potential to grow into any kind of cell.Cloning pointless
Yamanaka's work should take the wind out of the sails of the cloning industry, which has claimed the only way to get embryonic stem-cells exactly matching a patient is by cloning, because the cloned embryo is the patient's identical twin. But if an identical match can be achieved by Yamanaka's reprogramming of skin cells, cloning becomes pointless.
For years stem-cell researchers have sought to obtain embryonic stem-cells through nuclear transfer - transplanting an adult cell's nucleus into an egg emptied of its own nucleus, and then trying to trigger cell division to produce an embryo. Such cloning requires the donation of eggs from women - dangerous for the women - and is an expensive, difficult technique, even in animals. It has not been achieved with human cells.
By contrast, Yamanaka's work takes the research out of the arena of the cloning industry and into the field of molecular and cell biology where Australia has considerable expertise.
commentary, entitled "Simple switch turns cells embryonic", says: "The race is now on to apply the surprisingly straightforward procedure to human cells. ... The method is inviting. Whereas cloning with humans was limited by the number of available eggs and by a tricky technique that takes some six months to master, Yamanaka's method uses basic cells and can be accomplished with simple lab techniques."
Even Alan Trounson, ubiquitous spruiker for cloning and embryo experimentation, conceded: "This is great science. It takes us a big step closer to reprogramming adult cells."
Yamanaka was an orthopaedic surgeon before switching to research. With a small team early in 2004 Yamanaka worked up a list of 24 possible genes he thought were instrumental in cell programming.
Using retro-viruses to deliver the genes into mouse skin cells, Yamanaka and one of his students, Kazutoshi Takahashi, eventually narrowed the number down to four active genes that triggered the transformation.
That the process proved so straightforward surprised Yamanaka. Scientists assumed that reprogramming would require a complex arrangement of far more genes. "We were very surprised," he says. Nervous after the Hwang fraud debacle, Yamanaka had another researcher repeat Takahashi's work.
When he published his results in Cell Stem Cell
in August 2006, he took the unusual step of including every bit of lab data in the supplementary section of his paper.
Although Yamanaka's laboratory is small and doesn't have access to the vast funds available in the USA, he hints they may have more breakthroughs in store: "I think that this year or next year we could see reprogramming in human cells. I really believe it could come from our lab."
Breakthroughs as achieved by Yamanaka are a strong indicator that we should not expend any funds on cloning and experimentation on human embryos.
There is continuing good news of promising results from adult stem-cells, and clinical trials and treatments with stem cells from umbilical-cord blood, which is safely and painlessly collected after the birth of a baby.
Cord blood stem-cells are already used to treat leukaemia and other blood diseases, but scientists are also researching the use of these cells in the treatment of heart, liver and pancreatic diseases.US trial
Particularly promising is a trial in the US in which children with Type 1 diabetes were treated with their own cord blood. It lowered their glucose levels and reduced their need for insulin.
Not only should we avoid unethical and destructive experiments with human cloning, but any Australian punter would advise politicians not to put taxpayers' money on horses with poor, or no, performance. Stick with the winners - who, incidentally, happen also to be ethical.- Charles Francis, AM QC RFD, is a retired Melbourne lawyer and former Victorian state MP.