Synergistic effect of CQ on bortezomib-induced cell death.

<p>Cells were pre-treated with 50 µM CQ for I hour and then treated with bortezomib for 24 to 48 hours. (A) Determining cell death by flow cytometry. After treatment, cells were stained with 10 µg/ml PI and PI positive cells were counted as died cells. Data represent mean ± SD from 3 independent experiments. Asterisk (*) indicates P<0.01, significantly increased sensitivity analyzed by ANOVA. (B) Synergistic effect of CQ on bortezomib. Synergy was analyzed by CalcuSyn and synergy level was setup lower than 0.9. (C) PARP cleavage. PARP cleavage was analyzed by Western blotting using polyclonal anti-PARP antibody (1∶500). Lower bands (89 kD) indicate cleaved PARP. (D) Cell death in primary FL and DLBCL cells. Primary cells from liquid nitrogen were cultured in fresh medium for 3 hours. Cells were pre-treated with 30 µM CQ for 1 hour and then 20 nM bortezomib for 24 hours. Cell death was determined by flow cytometry. The significantly increased killing was analyzed by <i>t</i>-test.