MicroRNA-mediated iPS cells

The standard protocol for reverting somatic cells into induced pluripotent stem cells with viral vectors that introduce a quartet of transcription factors has low reprogramming efficiency.¹ Moreover, some human cell types are refractory to reprogramming with transcription factors. Now, researchers at the University of Pennsylvania report that microRNAs could address both problems, taking exogenous transcription factors out of the picture while increasing reprogramming efficiency.²

The UPenn protocol still uses viral vectors, which could pose safety issues in the clinic. Thus, the group now needs to replicate the findings using nonviral delivery of the miRNAs...