Page URL:

Study finds abnormalities in iPS Cells

7 February 2011
Appeared in BioNews 594

Adult human cells maintain a 'memory' when reprogrammed into a stem cell-like state, US scientists have found. The finding suggests the resulting iPS cells are not yet a viable alternative to human embryonic stem cells (ES cells) for modelling or treating disease.

The researchers from the Salk Institute in California found human iPS cells retained DNA methylation patterns - a type of epigenetic marker left on DNA - from their parent adult cells. The lead author of the study, Dr Joseph Ecker, said: 'they look fairly similar [to ES cells], but if you zoom in you find different signatures of what an iPS cell is'. Common among the five iPS cell lines the team examined were hotspots of failed reprogramming. There was also significant variability in reprogramming between iPS cell lines.

The findings agree with work last year by Dr George Daley and colleagues comparing mouse iPS and ES cells. However, the mouse study found the methylation differences between iPS and ES cells could be erased, which the latest study discovered wasn't the case for human cells.

iPS cells are considered an attractive alternative to ES cells as they do not require the destruction of human embryos. 'Embryonic stem cells are considered the gold standard for pluripotency, so we need to know whether - and if so, how - iPS cells differ from ES cells', Dr Ecker said. Dr Ecker and his colleagues hope identifying defect hotspots will spur the development of new techniques that can generate iPS cells more closely resembling ES cells.


Abnormalities discovered in stem cells from adults
New Scientist |  2 February 2011
Flaw in induced-stem-cell model
Nature |  2 February 2011
Hotspots of aberrant epigenomic reprogramming in human induced pluripotent stem cells
Nature |  2 February 2011
18 July 2011 - by Dr Lux Fatimathas 
US researchers have successfully converted human skin cells directly into brain nerve cells, skipping an intermediate stem cell stage. The new technique has the potential to aid research into neurodegenerative disorders of the brain, such as Parkinson's and Alzheimer's....
23 May 2011 - by Dr Rebecca Robey 
IPS (induced pluripotent stem) cells from mice can be recognised by their own immune system and destroyed, scientists at the University of California, San Diego, have found...
3 May 2011 - by Dr Marianne Kennedy 
A novel and more efficient method for generating induced pluripotent stem cells (iPSCs) from adult cells using small RNA molecules has been discovered by researchers at the University of Pennsylvania School of Medicine in the USA...
17 January 2011 - by Julianna Photopoulos 
An international team of researchers have found that both embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) show higher genetic abnormalities than other cells....
2 August 2010 - by Dr Rachael Panizzo 
Stem cells created from a patients' own tissue are subtly different from those derived from embryos in ways that may affect their therapeutic potential, two independent research groups have found. Both studies found induced pluripotent stem cells (iPS) retain an 'epigenetic memory' of their tissue of origin...
22 February 2010 - by Dr Sophie Pryor 
A new study has cast doubt over how useful human induced pluripotent stem (iPS) cells could be for research and the treatment of degenerative disease...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.