Abstract:

BACKGROUND: Up to now, numerous studies have addressed small RNA-mediated gene silencing following transcription, but few reports have concerned regulation of noncoding small RNA on other gene expression levels.
OBJECTIVE: To review gene regulation of noncoding small RNA on transcriptional level and its effects on proliferation and differentiation of stem cells.
METHODS: PubMed Database was undertaken to identify relevant articles on RNA interference mechanism and transcriptional gene silencing mechanism published from January 1998 to December 2009. The key words were “RNAi, transcriptional gene silencing” in English. The data were primarily examined, and references of each article were looked through. Repetitive researches were excluded, and 69 articles were relevant ones. Thus, a total of 28 articles were in accordance with inclusion criteria.
RESULTS AND CONCLUSION: Many species have transcription gene silencing, and the transcription gene silencing induced by small interference RNA in mammalian cells is a universal phenomenon. Furthermore, Dicer family and Agronaute family are two indispensable gene families to result in transcription gene silence, which also regulate the generation and differentiation of stem cells. Noncoding small RNA induces a high genetic transcriptional activity, and the regulation of small RNA has two modes, RNA/DNA mode and RNA/RNA mode.