(a) Structures of AdV-aGFP vectors. The arrow shows the orientation of transcription. Hatched box, shRNA cassette including the human U6 promoter. (b) (Left) Suppression efficiency of GFP RNA expressed from the cell line using anti-GFP vectors. FC-18 cells that constitutively express GFP RNA were infected with the vectors at MOI 50. (Right) Suppression efficiency of Cre RNA expressed from the AdV genome using anti-Cre vectors. FC-18 cells were doubly infected with AdV expressing Cre under the control of the CAG promoter at MOI 10 and anti-Cre vectors at MOI 50. Three days after infection, the amount of cytoplasmic RNA of GFP and Cre were measured using qPCR. The suppression efficiency for vector-infected FC-18 cells was calculated using copy numbers per cell, where uninfected FC-18 cells were denoted as 0% suppression of GFP RNA, while that of CV1 cells, the parent cells of FC-18 that do not contain the GFP gene, is denoted as the control of 100% suppression. Copy number, n = 6. *P < 0.05, **P < 0.01 compared with the E4L vector (unpaired Student's t-test).