Fig. 6.

Effect of IRX5 on E2F transcription factor 1 (E2f1) and proliferating cell nuclear antigen (Pcna) cell cycle regulatory gene expression. Expression of E2f1 and its target gene Pcna was elevated by Irx5 in RASMCs. Quiescent cells were transduced by Ad/LacZ, Ad/Irx5 (MOI = 200), or mock adenovirus (PBS) and incubated in serum-deprived medium for 0–48 h. Cells were harvested at 0–48 h. A and C: assessment of E2f1 and Pcna mRNA expression by quantitative RT-PCR, with β-actin used for normalization. B: Western blot analysis of E2F1 and PCNA protein levels. *P < 0.05; **P < 0.01 vs. control.