Figure 6.

Inhibiting MLC phosphorylation significantly decreased triptolide-induced apoptosis. U937 cells and blasts from one AML patient were pretreated with 20 μM ML-7, a MLC kinase inhibitor, for 2 h followed by treatment with or without 40 nM triptolide for 24 h. (a) The percentage of apoptotic cells was determined by FACS analysis using Annexin V/PI staining. Error bars represent the mean±S.D. (n=5). (b and c) Total protein lysates and cytosolic fractions were analyzed by immunoblotting using the indicated antibodies. Results were representative of three independent experiments