Figure 3
From: Inhibition of NF-κB activation sensitizes U937 cells to 3′-azido-3′-deoxythymidine induced apoptosis
Enhancement of AZT-induced apoptosis in U937 cells stably transfected with a dominant negative IκBα and its dependency on protein synthesis and association with failure of regulation of anti-apoptotic proteins. (a) U937-mIKB cells knock out for NF-κB (filled column) and their control counterpart U937-pcDNA (empty column) were treated with 0, 8, 32 and 128 μM AZT for 48 h. Apoptosis was evaluated by flow cytometry analysis of hypodiploid nuclei and expressed as mean values ± S.E. obtained from three independent experiments; asterisks indicate significant difference between the two cell lines (*P<0.05 or **P<0.010). (b) U937-pcDNA and U937-mIκB cells were incubated in the presence (filled column) or in the absence (empty column) of an inhibitor of protein synthesis, the CHX, at 0.1 μg/ml, before addition of 8, 32 and 128 μM AZT and susceptibility to apoptosis was measured after 48 h. Data are the means of hypodiploid nuclei ± S.E. from three experiments carried on in the same culture conditions. (c) U937-mIκB and U937-pcDNA cells were treated with 0, 8, 32 and 128 μM AZT. Expression of c-IAP, survivin and X-IAP was assessed by western blot analysis before (t0) and after 3, 6 and 18 h of treatment with AZT. One experiment representative of the three independent experiments performed is shown. β-actin expression, run on the same gel of X-IAP, indicates that an equal amount of protein was loaded for each sample. (d) Western blot analysis was quantified by densitometry analysis and values are expressed as OD-B kg /mm2 with respect to vehicle
