Key points from article :
DNA damage caused by factors such as ultraviolet radiation affect nearly three-quarters of all stem cell lines derived from human skin cells.
Researchers are turning to stem cells as ways of developing new treatments, known as cell-based therapies.
Stem cells were derived from embryos, but it is now possible to derive stem cells from adult skin cells known as induced Pluripotent stem cells.
Researchers at the University of Cambridge and Wellcome Sanger Institute used whole genome sequencing to inspect the entire DNA of stem cell lines.
They discovered that as many as 72% of the lines showed signs of major UV damage.
Professor Serena Nik-Zainal from the Department of Medical Genetics at the University of Cambridge said:
"Almost three-quarters of the cell lines had UV damage. Some samples had an enormous amount of mutations – sometimes more than we find in tumours."
Blood-derived iPSCs had lower levels of mutations than skin-derived iPS cells and no UV damage.
There were problems in generating neurons from iPSCs that have BCOR mutations.
“The DNA damage that we saw was at a nucleotide level,” says Professor Nik-Zainal.
There is a way round the problem: using whole genome sequencing to look in detail for the errors at the outset.
Dr Foad Rouhani, lead researcher said, "It is not a realistic aim to produce stem cell lines with zero mutations..."
The goal is to know more to make informed choices in using these cells.
Research by University of Cambridge and the Wellcome Sanger Institute, published in Nature Genetics.