An innovative technique of using induced pluripotent stem cells to treat heart damage and to repair cartilage has been developed by Dr. Shinya Yamanaka, Ph.D., and Kazutoshi Takahashi, Ph.D. However, the use of induced pluripotent stem cells over subcloning has been held back due to fears over safety. While IPSCs have been extensively studied in recent years, there has been some doubt over whether IPSCs have more genomic variations than cultured somatic cells.
Introducing adult cells at the earliest stages of development has raised concerns about the potential for genetic mutations to develop. However, a new study by the National Institutes of Health (NiH) has found the use of induced pluripotent stem cells does not carry a greater risk of mutations than using subcloning techniques.
The study was performed by the National Human Genome Research Institute at NiH. Donor cells taken from a healthy patient and an individual with familial platelet disorder were studied. Genetically identical copies of cells were created using induced pluripotent stem cell and subcloning techniques for both individuals. When the researchers sequenced the DNA from the clonal IPSCs and the subclones, mutations were found to have occurred in both.
The majority of the mutations discovered in clonal IPSCs and subclones were determined to be rare variants inherited from parent fibroblasts. The mutations for which no evidence of variants in the parental fibroblasts were found occurred at a similar level in both the cloned IPSCs and subclones. According to the researchers, the research shows that “iPSC reprogramming is not mutagenic.”
Co-author of the study and senior investigator in NHGRI’s Translational and Functional Genomics Branch, Dr. Pu Paul Llu, Ph.D., said “These findings suggest that the question of safety shouldn’t impede research using IPSC.” IPSCs should be safe to use for treating a wide range of medical conditions.
The study – iPSCs and fibroblast subclones from the same fibroblast population contain comparable levels of sequence variations – was recently published in Proceedings of the National Academy of Sciences.