Systemic network analysis identifies XIAP and IκBα as potential drug targets in TRAIL resistant BRAF mutated melanoma

IZI1551 is superior in killing melanoma cells than TRAIL or specific MAP kinase inhibitors. a Clonogenic outgrowth of mutBRAF A375 and Malme3M melanoma cells treated with dabrafenib (Dabra; 10？μM) for 8 days was compared to untreated cells (*p？≤？0.05; ***p？≤？0.001). b Parental and dabrafenib-conditioned melanoma cell lines A375 and Malme3M were treated with dabrafenib (Dabra; 10？μM) alone or in combination with trametinib (Trame; 1？μM). After 48？h apoptosis was determined using a Cell Death Detection ELISA (CDDE) (*p？≤？0.05; **p？≤？0.01; ***p？≤？0.001; n.s.？=？not significant). c A375 melanoma cells were treated with increasing doses of izTRAIL or IZI1551 as indicated (ng/ml). After 24？h apoptosis was determined using a CDDE (*p？≤？0.05; **p？≤？0.01; ***p？≤？0.001; n.s.？=？not significant). d The same dose kinetics of IZI1551 as in (c) was applied to primary human keratinocytes, fibroblasts and melanocytes. After 24？h apoptosis was determined using a CDDE (*p？≤？0.05; ***p？≤？0.001; n.s.？=？not significant). e Parental (par) and dabrafenib-conditioned (cond) melanoma cell lines A375 and Malme3M were treated with dabrafenib (Dabra; 10？μM) or IZI1551 (IZI; 50？ng/ml) alone or in combination. After 24？h of IZI1551 and 48？h of dabrafenib treatment apoptosis was determined using a CDDE (**p？≤？0.01; ***p？≤？0.001; n.s.？=？not significant) and f monitored by Western-blot analysis using antibodies against caspase-3 and PARP. α-tubulin served as loading control. For CDDE and clonogenic assay, the mean？±？SD of three independently performed experiments is shown. WBs represent one out of three independently performed experiment