Embryonic stem cells derived from somatic cloned and fertilized blastocysts are post-transcriptionally indistinguishable: a MicroRNA and protein profile comparison.

Therapeutic cloning, whereby somatic cell nuclear transfer is used to generate customized embryonic stem cells (NT-ES) from differentiated somatic cells of specific individuals, has been successfully performed in mice and non-human primates. Safety concerns have prevented this technology from being potentially applied to humans, as severely abnormal phenotypes have been observed in cloned animals. Although it has been demonstrated that the transcriptional profiles and developmental potentials of ES cells derived from cloned blastocysts are identical to those of ES cells derived from fertilized blastocysts (F-ES), a systematic analysis of the post-transcriptional profiles of NT-ES cell lines has not yet been performed. To investigate whether NT-ES cells are comparable to F-ES cells post-transcriptionally, we compared the microRNA and protein profiles of five NT- and matching F-ES cell lines by microRNA microarray, 2-D DIGE and bioinformatic analyses. Stem-loop real-time PCR and MS/MS assays were further performed to verify the expression of specific microRNAs and characterize differentially expressed proteins. Our results demonstrate that the ES cell lines derived from cloned and fertilized mouse blastocysts have highly similar microRNA and protein expression profiles, consistent with their similar developmental potentials and transcriptional profiles.