Figure 5

Effect of p53 gene induction on p21, p27 and p53 expression in NHLF. Expression of p21, p27 and p53 was examined in NHLF transfected with plasmids encoding wild-type (Wt) and dominant-negative mutation (DN) forms of the p53 gene, or an empty vector (Mock). A: Western blot analysis showed that Wt p53 transfection induced p21 protein expression and decreased p27 protein expression, whereas no significant changes in p21 and p27 protein expression were observed for the Mock- and DN-transfected cells. The photomicrograph shown is a representative image from four similar experiments, and the bar graphs show the density ratios of p21 (open bars), p27 (solid bars), and p53 (shaded bars) protein bands relative to β-actin bands. Data are expressed as mean ± SE (n = 4). *P < 0.05 versus Mock control. B: RT-PCR analysis showed that Wt p53 transfection induced p21 and p53 mRNA expression, whereas p27 mRNA was not affected. The bar graph shows the ratios of p21, p27 and p53 mRNA relative to the amount of β-actin mRNA. Open bars, Mock-transfected cells; solid bars, Wt p53-transfected cells. Data are expressed as mean ± SE (n = 6). *P < 0.05 versus Mock transfection.