Off-target messenger RNAs of G13 short hairpin RNA (shG13 off-targets)

Off-target messenger RNAs of the G13 short hairpin RNA (shG13) refer to a broad set of cellular transcripts that are unintentionally silenced by a specific shRNA sequence originally designed to target the Gnas gene. In landmark studies of RNA interference (RNAi) safety, shG13 was identified as a potent inducer of neurotoxicity in the mammalian brain due to its 'seed-based' off-target effects (Boudreau et al., 2009). The guide strand of shG13 possesses a seed sequence (nucleotides 2-8) that is complementary to the 3' untranslated regions (UTRs) of many essential mRNAs, leading to their unintended degradation via a mechanism similar to endogenous microRNAs. This off-target activity can cause severe phenotypic changes, including neuronal loss and motor deficits, which are independent of the intended silencing of the primary target gene. Consequently, these off-target mRNAs are not therapeutic targets themselves but represent a major safety hurdle in the development of shRNA-based gene therapies. Research into these interactions has led to the development of improved RNAi platforms, such as artificial microRNAs (miRNAs), which reduce off-target signatures and improve safety profiles (McBride et al., 2008).

Other names

shG13 off-target transcriptsG13 shRNA seed-matched mRNAsGnas-targeting shRNA off-targetsRNAi-induced off-target mRNAs

The G13 shRNA guide strand, once processed by Dicer and loaded into the RNA-induced silencing complex (RISC), utilizes its seed region (nucleotides 2-8) to recognize and bind to partially complementary sequences in the 3' untranslated regions (UTRs) of various off-target mRNAs, triggering mRNA destabilization and translational inhibition (Boudreau et al., 2009; PubMed: 19352365).