Fig. 7

Antisense oligonucleotide-mediated regulation of p53. (A) Down-regulation of p53 proteins by treatment of SW480 cells with 400 nM of p53 AS oligonucleotides leads to a 2-fold reduction of total cellular p53 proteins, compared to a control (RC) oligonucleotide. As expected, the Ras level remained unaffected by the oligonucleotide treatment. (B) Protein levels of p53 and p21^(waf1/cip1) under combined treatment of FTS and antisense (lane 1); FTS and control (lane 2); DMSO and antisense (lane 3); and DMSO and control (lane 4). Antisense treatment of SW480 cells not only reduced the level of p53 but also the level of p21^(waf1/cip1) 3-fold, compared to a control oligonucleotide (lanes 1 and 2). Lane 4 shows the baseline for p53 and p21^(waf1/cip1) in those cells, and lane 3 shows a slightly reduced level of p53 and an unaffected p21^(waf1/cip1) level. Actin served as an internal control to demonstrate equal protein amounts in the respective lanes. One of three representative experiments is shown.