Induced pluripotent stem cells don't increase genetic mutations

Despite its immense promise, adoption of iPSCs in biomedical research and medicine has been slowed by concerns that these cells are prone to increased numbers of genetic mutations. 

A new study by scientists at the National Human Genome Research Institute (NHGRI), suggests that iPSCs do not develop more mutations than cells that are duplicated by subcloning.

Subcloning is a technique where single cells are cultured individually and then grown into a cell line. The technique is similar to the iPSC except the subcloned cells are not treated with the reprogramming factors which were thought to cause mutations.

"This technology will eventually change how doctors treat diseases. These findings suggest that the question of safety shouldn't impede research using iPSC," said Pu Paul Liu.

Liu and his collaborators examined two sets of donated cells: one set from a healthy person and the second set from a person with a blood disease called familial platelet disorder. Using skin cells from the same donor, they created genetically identical copies of the cells using both the iPSC and the subcloning techniques.

They then sequenced the DNA of the skin cells as well as the iPSCs and the subcloned cells and determined that mutations occurred at the same rate in cells that were reprogrammed and in cells that were subcloned.

Most genetic variants detected in the iPSCs and subclones were rare genetic variants inherited from the parent skin cells. This finding suggests that most mutations in iPSCs are not generated during the reprogramming or iPSC production phase and provides evidence that iPSCs are stable and safe to use for both basic and clinical research, Dr. Liu said.