Retinoic Acid Induces Apoptosis of Prostate Cancer DU145 Cells through Cdk5 Overactivation
Figure 3
RA-triggered Cdk5 activation is blocked by p35 cleavage inhibitor. DU145 cells were treated with different dosages of Calpeptin (CP) plus 10 μM RA after 1-day serum-free pretreatment. After 4-day incubation, protein was extracted from cell lysate and p35/p25 and Cdk5 immunoblottings were performed as described in Materials and Methods. β-actin serves as an internal control. Cdk5 activity was detected by in vitro kinase assay using histone H1 as a substrate. (b–d) The quantitative data respectively revealed the results of p35 cleavage, p25 formation, and Cdk5 activation. The independent experiments were repeated 3 times. Data are represented as means ± SEM; versus control group (CP = 0).
