Pluripotent stem cells have successfully been generated from mouse and human somatic cells by introducing genetic material, either stably or transiently (see blog “Human iPS cells…”). The iPS field is rapidly evolving and has now successfully made pluripotent cells without introducing any vectors. Zhou et al showed that mouse fibroblasts could be reprogrammed to a pluripotent state by the addition of recombinant cell-penetrating reprogramming proteins. These novel protein-induced pluripotent stem cells (piPSCS) differentiated into all lineages in culture and the developing embryo.
The advancement of piPSCS now avoids the need to introduce genetic material into cells. This major breakthrough with mouse cells will hopefully be confirmed soon by other laboratories and applied to human cells. In addition, piPSCS still need to be compared to embryonic stem cells to ensure that they are similar and therefore equally relevant to basic research, drug screening, disease modeling and clinical trials.
1. Zhou, et al (2009) Cell Stem Cell