A protein known as RE1-silencing transcription factor (REST) blocks the expression of an miRNA that prevents embryonic stem cells from reproducing themselves and causes them to differentiate into specific cell types, report scientists at the The University of Texas M. D. Anderson Cancer Center.
In studies using mouse embryonic stem cells, the researchers found that REST disarms a specific miRNA called miR-21. They observed that miR-21 suppresses embryonic stem cell self-renewal and is associated with a corresponding loss of expression of critical self-renewal regulators such as Oct4, Nanog, Sox2, and c-Myc. REST counters this by suppressing miR-21 to preserve the cells’ self-renewal and pluripotency, according to the investigators.
These experiments also revealed that REST is bound to the gene chromatin of a set of miRNAs with the potential to target self-renewal genes and that REST controls transcription of 11 miRNAs.
The study was published on March 23 in Nature.