Figure 2

Myc regulates the Aurora-A promoter. A. HCT116 cells were synchronized as above, total cell extracts were prepared and analyzed using antibodies directed against p21waf1, p53 or its serine 15 phosphorylated form (n = 3). B. HCT116 p21-/- or HT29 cells (presenting a mutated form of p53) were treated as described above and Aurora-A and p21waf1 expressions were measured by western blot using tubulin as a control (n = 3). C. HCT116 cells were synchronized in the G2 phase of the cell cycle (serum 9hr) or treated with sn38 for the indicated times. The expression of Myc and Aurora-A was analyzed by western blot on total cell extracts (n = 3). D. LS174T cells were grown in the absence or presence of doxycyclin as indicated. Myc and Aurora expressions were then analyzed by western blot analysis (n = 3). Two different clones of the LS174T colorectal cell line (named LS174T#1 and LS174T#2) were used, each expressing a doxycyclin-inducible expression vector that drives the expression of different siRNAs.