Figure 7.

CHX blocks p21^WAF1 expression and potentiates p53-mediated apoptosis. (A) Cells were switched to 32°C at the time of UV or CHX treatment, and p53, p21^WAF1, Bax, and actin levels were assessed by Western blot analysis 6 h later. (B) HT29-neo and HT29-tsp53 cells were subjected to protocols 1 (white bars), 2 (black bars), and 4 (gray bars) with CHX for 48 h. The induction of apoptosis in mock-treated controls was subtracted from that determined for each treatment. CHX significantly stimulated the induction of apoptosis in HT29-tsp53 cells subjected to protocol 2. Values are expressed as means ± SEM from two to five independent experiments.