Figure 3

Catechins induced caspase activation, Bcl-xL downregulation, and the degradation of PML-RARα fusion protein in NB4 cells. (A) Western blot analysis of caspase-3, −8, −9, and PARP in NB4 cells treated with 100 μM and 200 μM Catechins for 24 h. Caspase-3 was activated with caspase-8 and caspase-9 and PARP cleaved. (B) The expression of Bcl-2, Bcl-xL and Bax protein were determined by Western blot. Bcl-xL expression was reduced in NB4 cells treated with 100 μM and 200 μM Catechins for 24 h. (C) PML-RARα was decreased upon treatment with 100 μM and 200 μM Catechins at 12 h and 24 h. (D and E) PML-RARα was not affected by pan-caspase inhibitor ZVAD-FMK (50 μM), but partially blocked by proteasome inhibitor bortezomib (0.1 μM). Three independent experiments were performed and representative results were shown.