NF-κB inhibition down-regulates the expression of caspase-4.

<p>(<b>A</b>) SH-EP1 cells transfected with control vector (Ctl) or DN-IκBα expression vector (DN-IκBα) were lysed, and the expression levels of various caspases were detected using corresponding antibodies. (<b>B</b>) The expression level of caspase-4 was quantified. The caspase-4 level of DN-IκBα cells is expressed as a percentage of the level measured in control SH-EP1 cells. (<b>C</b>) The relative mRNA levels of caspase-4 in DN-IκBα cells were determined by qPCR. (<b>D</b>) The dual luciferase reporter assay was performed to evaluate the effect of DN-IκBα on caspase-4 promoter activity. DN-IκBα could significantly induce the activity of caspase-4 promoter, NF-κB binding site, but not NF-κB binding site mutant (mt). RLA represents relative luciferase activity. Data are representative of three independent experiments and shown as average ± s.e.m. (bars) values. **<i>P</i> <0.01 and ***<i>P</i> <0.001.