FIGURE 7.

p38 activation in cadein1-induced apoptosis depends on p53 deficiency in cancer cells with functional MMR. A, HT29 and DLD-1 cells were treated with different concentrations of cadein1 for 12 h. The activation of p38 was analyzed by immunoblots with anti-phospho-p38 and anti-p38 antibody. B, HT29 cells were transfected with pcDNA3.1-p53 expression plasmid or vector only (empty) and treated with different concentrations of cadein1 for 12 h. Cell extracts were analyzed by Western blots with anti-phospho-p38 and anti-p38 antibody. C, ectopic expression of dominant-negative p38 (DN-p38) alleviated the effect of cadein1. HeLa cells were transfected with pcDNA3.1 vector (V) and plasmids for wild type p38 (Wt-p38) and dominant-negative p38 (DN-p38). One day after transfection the cells were treated with 4 μm of cadein1 for 12 h. PARP was analyzed by an immunoblot. α-Tubulin protein is shown as a loading control. D, HeLa and HCT116-Ch3/E6 cells were pretreated with 10 μm SB203580 for 1 h, and then 4 μm cadein1 was added to cells for the indicated times. PARP and cleaved caspase3 were analyzed by immunoblots. Actin was used as a loading control.