Know which way to miRoam: Red means ‘GO’, Green ‘STOP’!
By Carla B. Mellough
Induced pluripotent stem cells (iPSC) are shown to have many of the characteristics of human embryonic stem cells (hESC) including prolonged proliferative capacity and differentiation across all germ layers. The therapeutic potential of human iPSC (hiPSC), however, remains controversial. Whilst the use of hiPSC would overcome some of the ethical issues surrounding hESC, their suitability and usefulness as a replacement cell type has recently fallen into question. For example, concerns have been raised over the retention of epigenetic memory from the iPSC cell of origin (see iPSC don’t forget their origins) which questions their level of reprogramming, and may be the cause of their apparently biased pluripotent potential. However, conversely, it has been suggested that in fact iPSC and hESC are very similar (see Similar Human iPSC and ESC Chromatin States Suggests Usefulness in Regenerative Medicine). Various hiPSC clones differ with regards to their level of reprogramming and differentiation potential and being able to identify those of greatest potential therapeutic value would no doubt help the advancement of hiPSC research.