RNAa-Mediated Gene Activation in the Regulation of Stem Cell Fate

Stem cell fate is governed by complex transcriptional networks and dynamic chromatin architectures, with RNA molecules acting as critical regulators. Traditionally, small RNAs have been associated with gene silencing; however, growing evidence reveals that certain RNA species can also activate transcription, a phenomenon termed RNA activation (RNAa). This evolutionarily conserved mechanism functions through both synthetic small activating RNAs (saRNAs) and endogenous RNA molecules, including promoter-targeting microRNAs, small modulatory double-stranded RNAs, and circular RNAs. By modulating chromatin accessibility and engaging the transcriptional machinery, these RNAs orchestrate gene expression programs that control pluripotency maintenance and lineage-specific differentiation in stem cells. This review integrates emerging mechanistic insights and functional evidence to provide a comprehensive perspective on RNAa-mediated gene activation in stem cell biology and highlights its potential as a precise tool for controlling cell fate through epigenetic modulation.