Figure 3. The inhibitory effects of the lenti-LEP503-HSV-tk/GCV system on HLECs. A: The transcriptional detection of HSV-tk mRNA driven by lenti-LEP503-HSV-tk-EGFP vector in Hela cells (left) and HLECs (right). ACTB (590 bp) was used as the internal control. B: Semi-quantitative analysis for the RT–PCR results (n=3). The intensities of HSV-tk mRNA were normalized to ACTB (n=3). C, D: Cell survival analysis by EGFP expression in HLECs 24 h after infection, followed 48 h by vehicle control treatment (C) and by GCV treatment (D). Scale bar: 100 μm. E: Cell survival analysis after exposure to a series of dose of GCV with MTT assay (n=5). F: The time-effect curve of the lenti-LEP503-HSV-tk/GCV system on HLECs and Hela cells with the CCK-8 assay (n=4). * p<0.05 and *** p<0.001, compared with Hela cell group (B), vehicle control (0; E) and control time point (F).