NF-[kappa]B regulates STAT3 activation in CLL cells. (A) Effect of NF-κB inhibition on pSTAT3 and Mcl-1 expression. CLL cells were incubated for 24 hours in the presence or absence of 2μM BAY11-7082, before probing for indicated proteins in CLL cell lysates by Western blot. pIκBα levels were also measured as a control for the effects of BAY11-7082. (B) Graphical representation of the data shown in panel A, showing the percentage inhibition of pSTAT3 and Mcl-1 after BAY11-7082 treatment. Results are representative of 3 different CLL patient samples and are expressed as the percentage inhibition relative to 0 hours untreated CLL cells (mean ± SEM). (C) CLL cells were incubated for 12 hours in the presence or absence of a control peptide (c) or the SN50 NF-κB peptide inhibitor (i), before probing for pSTAT3 and Mcl-1 expression by Western blot.