Effect on gene expression after administration of siRNA/siLNA targeting GFP

siRNA mediated gene knockdown has been shown to be extremely sequence specific. However, off-target gene regulation due to partial sequence homology has also been reported. Furthermore, sequence unrelated effects on gene regulation can occur when siRNA is applied in vivo. In this experiment we investigated off target gene regulation due to treatment of mice with siRNA and LNA modified siRNA targeting GFP. Off target gene regulation was observed and was markedly reduced upon introduction of LNA modifiecation in siRNA. Keywords: comparison compound NMRI nu/nu mice were treated with saline (control), siRNA or siLNA for three weeks. Then the mice were sacrificed and tumor total RNA was isolated. The effect of siRNA/siLNA treatment was evaluated by comparing gene expression of saline treated animals with that of siRNA and siLNA treated animals respectively.