Fig. 5.

Effects of FC2 on the NF-κB pathway in MDA-MB-231 and HEK293 cells. A) MDA-MB-231 cells treated with 20 μM FC2 and then stimulated with 50 ng/mL TNF. NF-κB markers (pp65, pTAK1, cIAP1, cIAP2, XIAP, pMKK3/6, MKK6 and IκBα) were chosen to monitor the activation of the pathway. (B) In the presence of FC2, pp65 levels increase, suggesting a more prominent phosphorylation of p65 and NF- κB activation, and this effect is particularly evident at 1 and 5 h. Along these time ranges also IκBα levels are significantly different in the absence/presence of FC2, indicating a delay in protein levels’ recovery upon TNF-induced degradation. Densitometry analysis was performed with ImageQuant 5.2. C) Immunoprecipitation of XIAP overexpressed in HEK293. Left panel: lysates; right panel, immunoprecipitation of XIAP with Myc revealed a more pronounced recruitment of TAB1 and TAK1 upon treatment with FC2.