MOMP and effect of caspase inhibitor or an antioxidant on MOMP in gossypol-treated CLL lymphocytes. (A) Gossypol induces mitochondrial outer membrane permeabiliztaionn (MOMP) in CLL lymphocytes. (i) Cells were incubated for 24 hours either alone (control) or with 30 μM gossypol, and the MOMP was measured by flow cytometry using a double-staining (TMRM and FITC-conjugated annexin V). (ii) Percentage of MOMP in CLL primary cells from 5 patient samples treated with gossypol. (B) Effect of a caspase inhibitor on gossypol-induced MOMP. CLL cells were incubated for 24 hours alone (C, control), with Z-VAD.fmk (Z), with 30 μM gossypol (G) plus Z, or with gossypol (G), and the MOMP was measured by flow cytometry as described in panel A. Percentages of MOMP in CLL primary cells from 6 patients are provided. (C) Effect of antioxidant (NAC) on gossypol-induced MOMP. CLL cells were incubated for 24 hours alone (C, control), with NAC, with gossypol (G) plus NAC, or with 30 μM gossypol, and then the MOMP was measured as described in panel A. Percentages of MOMP in CLL primary cells from 6 individual patients are provided.