It might soon be possible to grow human body parts in a lab, even from older adults’ stem cells.
For the first time ever human cloning has been used to create stem cells for adults in a breakthrough which could lead to tissue and organs being regrown. Scientists have turned the skin cells of a 75-year-ol man into stem cells, which can grow into any type of tissue in the body.
Using the cloning technique which produced Dolly the sheep in 1996, researchers were able for the first time to turn adult human skin cells into stem cells, which can grow into any type of tissue in the body.
Remarkably they even managed to do it with the cells of a pensioner – a 75-year-old man – raising the prospect that body parts could be regenerated in old age.
The breakthrough could lead to new tissue-transplant operations for a range of debilitating disorders, such as Parkinson’s disease, multiple sclerosis, heart disease and spinal cord injuries.
Last year a team managed to create stem cells from the skin cells of babies but it was unclear whether it would work in adults because cells mutate with age.
However a team at the Research Institute for Stem Cell Research at CHA Health Systems in Los Angeles and the University of Seoul said they had achieved the same result with two men, one aged 35 and one 75.
“The proportion of diseases you can treat with lab-made tissue increases with age. So if you can’t do this with adult cells it is of limited value,” said Robert Lanza, co-author of the research which published in the journal Cell Stem Cell
The technique works by removing the nucleus from an unfertilized egg and replacing it with the nucleus of a skin cell. An electric shock causes the cells to begin dividing until they form a ‘blastocyst’ – a small ball of a few hundred cells.
In IVF it is a blastocyst which is implanted into the womb, but with this technique the cells would be harvested to be used to create other organs or tissues.
However, the breakthrough is likely to reignite the debate about the ethics of creating human embryos for medical purposes and the possible use of the same technique to produce cloned babies – which is illegal in Britain.
Although the embryos created may not give rise to a human clone even if implanted in a womb, the prospect is now scientifically closer.
However scientists have been trying for years to clone monkeys and have yet to succeed.
Dr Lanza admitted that without strong regulations, the early embryos produced in therapeutic cloning “could also be used for human reproductive cloning, although this would be unsafe and grossly unethical”.
However, he said it was important for the future of regenerative medicine that research into therapeutic cloning should continue.
Reproductive biologist Shoukhrat Mitalipov of Oregon Health and Science University, who developed the technique last year said: “The advance here is showing that (nuclear transfer) looks like it will work with people of all ages.
“I’m happy to hear that our experiment was verified and shown to be genuine.”
However the high cost of creating stem cells means that at present “only a few wealthy old men could do it,” said Lanza.
A big barrier to producing patient-specific stem-cell lines for tens of millions of people this way is that few women want to donate eggs, a sometimes painful process.
But many people have genetically similar immune systems, Lanza said, so just “100 human embryonic stem cell lines would generate a complete match for over half the American population.