Rose, S.D., Kim, D.H., Amarzguioui, M., Heidel, J.D., Collingwood, M.A., Davis, M.E., Rossi, J.J. and Behlke, M.A.
Notes: Having observed that blunt 27mers had increased potency in RNAi compared to 21mers or 27mers with 3' or 5' overhangs, these authors investigated what differences may account for these changes in gene silencing activity using the same target sequence in enhanced green fluorescent protein (EGFP). For one experiment, a PCR-generated fragment of the EGFP coding region spanning sites EGFPS1 and EGFPS2 was cloned into psiCHECK™-2 Vector in both sense and antisense orientations. Also, a PCR-generated fragment of the human heterogeneous nuclear ribonucleoprotein H (hnRNPH) coding region spanning sites H1 and H3 was similarly cloned in sense and antisense orientations. HEK293 cells were transfected with 150ng EGFP sense and antisense vectors plus EGFPS2 or control duplex RNAs. HCT116 cells were transfected with 100ng sense and antisense hnRNPH vectors with H3 or control duplex RNAs. The Dual-Luciferase® assay was used to evaluate luciferase expression 24 hours post-transfection. In a separate EGFP RNAi experiment, the Steady-Glo® Luciferase Assay System was used to monitor firefly luciferase activity to normalize transfection of HEK 293 cells.
A further RNAi experiment targeted the firefly luciferase gene in the pGL3-Control Vector cotransfected with 20, 2 or 0.4 nM siRNA duplexes into HeLa cells. After 48 hours, the cells were lysed and 10µl tested using the Luciferase Assay System. To test the level of expression of human La antigen targeted for gene silencing, total RNA was harvested from HeLa cells using the SV 96 Total RNA Isolation System, reverse transcribed and used in real-time PCR. (3289)