Retinoic Acid Induces Apoptosis of Prostate Cancer DU145 Cells through Cdk5 Overactivation

Figure 5

RA-triggered caspase 3 activation can be diminished by p35 cleavage inhibitor. DU145 cells were treated as follows: control, RA (10 μM), RA + CP, CP (10 μM) for 4 days after 1-day serum-free pretreatment. (a) Cleaved caspase 3, p25, and (e) cleaved PARP were detected by immunoblotting with specific antibodies as described in Materials and Methods. β-actin and α-tubulin serve as internal controls. Cdk5 activity was detected by in vitro kinase assay using histone H1 as a substrate. (b–d) and (f) The quantitative data, respectively, revealed the results of cleaved caspase 3, p25 formation, Cdk5 activation, and cleaved PARP. The independent experiments were repeated 3 times. Data are represented as means ± SEM; ^∗∗𝑃<0.01 versus control group; ⁺⁺𝑃<0.01 versus RA alone group.

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