Fig. 2

FLP recombinase-mediated removal of SV40 LTA effectively reverses the cell proliferative activity of imPACs, while imPACs are non-tumorigenic in vivo. A & B Subconfluent imPACs were infected with Ad-GFP or Ad-FLP with high efficiency as shown on 24 h (1 day) post infection (A). Total RNA was isolated at 48 h after infection and subjected to RT-qPCR analysis to determine SV40 LTA expression using SV40 LTA-specific primers (B). ** p < 0.01 compared with that of the Ad-GFP infection group. C & D The imPACs are not tumorigenic in vivo. The imPAC and human lung cancer PC9 cells were stably tagged with firefly luciferase (FLuc) and subcutaneously injected into athymic nude mice as described in Methods. The mice were subjected to whole body optic bioluminescence imaging at the indicated time points (C). Representative images are shown. The acquired data were quantitatively analyze using the Living Image software (D). ** p < 0.01, compared with that of the PC9 cell injection group