It's been a divisive issue for as long as it's existed, but the topic of human embryonic cloning has been thrust back into the spotlight this week with the news that researchers in the US have successfully produced human embryonic stem cells (hESCs) from adult cells for the first time. This is big news because hESCs have the potential, in theory, to become any type of adult cell - opening the possibility for repairing damaged tissues in previously unthinkable ways. Neatly, this was exemplified this month by the revelation that a blind patient has had his sight restored so significantly using hESC therapy that he is now legally able to drive. Such therapy could also be used in therapies for paralysis, myocardial damage, diabetes, and many other disorders.
This new method for generating hESCs relies on harvesting cells from an adult patient (typically from the skin) and then fusing them with oocyte (egg) cells that have been emptied of genetic material. This, in effect, generates a single-cell embryo with the genome of the original adult cell, which can then begin to develop into a multi-cellular body. The most recent work has identified the precise chemical signals that need to be applied to the cells, and at which stages, to generate hESCs. At present, it is illegal in most countries to allow such clones to develop beyond 14 days of age, yet it is still feasible that useful numbers of hESCs could be obtained from even such young embryos.
This promising development hopefully represents the start of an increased investment in the field of therapeutic human embryonic cloning, but is also very likely to reignite the fierce debate over the ethical issues linked to the generation of human clones. Such debate led to severe restrictions in funding and autonomy in hESC research in the United States during the Bush regime, which was subsequently overturned by the Obama administration in 2009. It is my sincere hope that the typically alarmist ways that this kind of work is often portrayed in the mainstream media (such as those that accompanied the cloning of Dolly the sheep) do not hamper scientific policy or public acceptance of such potentially ground-breaking advances.
This is, admittedly, a short post about something that you may already have read, but I am using this, dear reader, to whet your appetite for stem cells as I will be finding my way to writing a much more in depth and revealing post soon about what stem cells actually are and how the abstract 'treatments' that I mention above actually work. Watch this space for more soon.