Short hairpin RNAs or small hairpin RNAs are RNA molecules with a hairpin structure that allow the silencing of target genes via RNA interference (RNAi). shRNAs are produced inside the cell and provide an alternative method to the chemical synthesis of siRNA.
shRNAs are single-stranded RNA molecules processed by Dicer to cause gene suppression, similar to siRNAs.
Several vector-based methods use the RNA polymerase III (Pol III) promoter to drive the expression of the sense and antisense strands separately. Both strands hybridize in vivo to make the siRNA. Other vectors use Pol III to express short "hairpin" RNAs (shRNAs), individual transcripts that adopt stem-loop structures. shRNAs are processed into siRNAs by the RNAi machinery.
Reference
Moore CB, Guthrie EH, Huang MT, Taxman DJ. Short hairpin RNA (shRNA): design, delivery, and assessment of gene knockdown. Methods Mol Biol. 2010;629:141-58. [PMC]
short hairpin RNA