Figure 1.
(A) Stimulation of S100A2 mRNA expression after selective induction of p53 family members. In RNA preparations from DLD-1 colorectal adenocarcinoma cells stably transfected with tet-off vectors expressing members of the p53 family S100A2 mRNA levels were measured. Relative mRNA levels were determined by real-time RT–PCR and changes in expression are given as induction factor comparing mRNA levels 9 h after tet-off induction to levels before induction. Averages of three experiments including standard deviations are shown. Average CT values are denoted before (no) and after (ind) tet-off induction. t-test was carried out to yield statistic significance values (**P-value ≤ 0.01; *P-value ≤ 0.05). GAPDH expression was used for standardization. (B) Stimulation of S100A2 protein expression after induction of TAp63γ. S100A2 protein was analyzed by western blot comparing expression before (n) and 9 h after (i) tet-off regulated p53 or TAp63γ expression in the colorectal adenocarcinoma cell line DLD-1. In each lane 60 µg of total cell lysate was loaded. S100A2 protein was detected with polyclonal antibodies raised against full-length human S100A2. Lysates from HCT116 cells (15 µg) transfected with an S100A2-expressing plasmid and HaCaT cells (5 µg) served as positive controls. Induction of p53 and p63 expression was analyzed by comparison of cell lysates before (n) and after induction (i) of the transgenes. Detection of β-actin served as a loading control.