Figure 6.

XN down-regulates the NF-κB reporter activity induced by TNF and TNF-signaling components. (A) XN inhibits TNF-induced NF-κB–dependent reporter gene (SEAP) expression. A293 cells were transiently transfected with an NF-κB–containing plasmid linked with the SEAP gene. Cells were treated with XN for 4 hours at the indicated concentrations followed by 1 nM TNF for 24 hours, cell supernatants were collected and assayed for SEAP activity. The results are expressed as the fold activity over the activity of the vector control. DN indicates dominant-negative. (B) XN inhibits NF-κB–dependent reporter gene expression induced by TNF, NIK, TAK1, TRADD, and TRAF-2. A293 cells were transiently transfected with the indicated plasmids along with an NF-κB–containing plasmid linked with the SEAP gene for 24 hours. After medium change, cells were treated with XN (50 μM) for 4 hours. Where indicated, cells were exposed to 1 nM TNF for 24 hours. Cell supernatants were assayed for SEAP activity. The results are expressed as the fold activity over the activity of the vector control.