It was only a few years ago that scientists figured out how to reprogram adult cells to make them act like multipurpose stem cells, but the next discoveries are coming fast and furious. Researchers had previously transformed human skin cells into so-called induced pluripotent stem (iPS) cells that can grow into any type of tissue; now, a new study reports that the same feat has been accomplished with pig cells. The achievement raises the possibility that genetically engineered pigs could be reared as organ donors, researchers say.
The created iPS cells could be genetically altered, and then cloned to produce pigs with certain traits. By adding or deleting certain genes, for example, researchers could produce pigs whose organs can be transplanted into patients without them being recognised and rejected. Efforts to do such xenotransplants have already been under way for at least a decade, but iPS cells are easier to genetically engineer and grow in the lab than pig embryos, opening up new possibilities for xenotransplantation [New Scientist]. Pigs are considered potential organ donors because their organs are already similar to those of humans in size and function.
In the study, which will be published in the Journal of Molecular Cell Biology, lead researcher Lei Xiao reprogrammed cells taken from a pig’s ear and bone marrow, using a cocktail of chemicals introduced into the cells via a virus. Tests showed that the reprogrammed cells were capable of becoming any of the cell types that make up the three layers in a developing embryo [BBC News].
The reprogrammed cells could be manipulated to replicate the effects of human genetic diseases, which could allow researchers to test out new therapies for those diseases on pigs, or the technology could be used in animal husbandry. But researchers are most excited by the new potential to grow organs for humans. Comments stem cell expert Chris Mason: “This breakthrough to produce pig stem cells potentially reinvigorates the quest to grow humanised pig organs such as pancreases for diabetics and kidneys for chronic renal failure…. Whilst the xenograft approach may not necessarily be the long-term solution, it may represent a major step change in the treatment of organ failure, which potentially could deliver real benefit to millions of patients within a decade” [BBC News].
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DISCOVER: Saviors introduces the pigs who could one day be organ donors
Image: flickr / garrulus
June 3rd, 2009 at 3:39 pm
They’re still using viral vectors, which, according to various news reports, seems to be the major stumbling block, in that they may cause cancerous tumors in the person they were saving.
And, honestly, we can already grow heart tissue in petri dishes from stem cells that will start to beat when enough muscle cells become present. Do we really want to grow these organs in pigs instead? We have zero clue as to what transgenically cloned organs will do to the recipient.
It may pan out, but I doubt that we’ll have this available within ten years. I doubt the FDA human-approved trials could start within that time frame.
Normally I’m a cheerleader for this kinda thing – but we can keep a lung alive in a jar for 12 hours, and fake a pig heart being alive for surgery purposes – within ten years we’re more likely to have in-vitro organ cloning than in-porcine organ cloning, at least from a safety standpoint. At least, with that method you only have to worry about random cancer from the viral vectors used to induce pluripotentcy in human stem cells, and not the viral vectors + whatever happened to be living inside your host pork at the time of organ cloning.
And, honestly, the way animals and treated by science and industry, on a moral stance alone I’d rather have in-vitro than in-porcine organ cloning. Less chances for abuse. Factory farming is bad enough, can you imagine factory organ farming?
November 1st, 2009 at 1:43 pm
Actually, I think pigs being raised for use as organ donors would be much better treated than pigs being raised as mere food, since their proper care in the case of being food is much less important.
Ethically it’s more immoral to raise an animal to eat since we don’t strictly need meat to survive, than it is to raise them for organs that will save our lives. So I don’t see a problem that way either. Unless we make laws mandating vegetarianism for ethical reasons I don’t see why we wouldn’t permit this.