Figure 6
GSH metabolism regulates the phosphorylation of STAT-Ser727 of CLL-BC. (a and b) Comparison of apoptosis, ROS, pSTAT3Ser727 and total STAT3 expression of CLL-BC cultured alone for 4 days in the presence or absence of NAC (1 mM) or GSH (2 mM). Where indicated, PEITC (1–5 μM, 5 h) was added at the end of the culture. (c) Time course of ROS, pSTAT3Ser727 and total STAT3 expression of CLL-BC cultured alone in the presence of PEITC (5 μM) for the indicated time. ROS were measured by DHE staining of CD45/CD19+/CD5+ cells; pSTAT3Ser727 and total STAT3 levels were evaluated upon immunolabeling/FCM. Data are expressed as relative to untreated cells. The mean±S.E.M. of four separate experiments with four different CLL patient samples are shown (*P<0.05; **P<0.01; ***P<0.001; ****P<0.0001). (d) FCM of pMEK (right) and pSTAT3Ser727 (left) of CLL-BC upon a two-day culture in the absence (black) or presence of 10 nM (dark grey) or 100 nM (medium grey) of MEK inhibitor PD0325901. B cells were labeled with rabbit control (light grey), pMEK or pSTAT3Ser727 antibodies, as indicated. Results are expressed as mean fluorescence intensity (arbitrary unit, a.u.)
