A comparative analysis of the protein inventories of embryonic stem cells versus induced pluripotent stem cells is reported online in Nature Methods. Although the discovered variations in protein expression were subtle, the findings may help explain differences in the abilities of these cells to differentiate into diverse cell types.
Like embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) can develop into any type of cell in the human body. iPSCs, though, can be generated from adult tissues, avoiding the ethical issues surrounding research and medical uses of ESCs. However, the question of whether iPSCs are biologically equivalent to ESCs remains open.
Joshua Coon and colleagues use high-resolution mass spectrometry-based proteomics analysis to assess the protein inventory of four human ESC lines and four iPSC lines. With repeat analyses, they found small but reproducible differences in protein expression between ESCs and iPSCs. Their results suggest that iPSCs retain some characteristics of the differentiated cells from which they were derived, which might bias them into developing into particular cell types.
The authors have made their data freely available in a new resource called the Stem Cell-Omics Repository (SCOR).