PACS-2 deficiency protects from TRAIL-induced apoptosis and prevent sensitizations by the SMAC mimetic.

<p>(A) Wild-type (WT) or shPACS-2 HuH-7 cells were treated with TRAIL (10 ng/ml) ± JP1584 (500 nM) for 6 hr. Apoptosis was assessed morphologically after DAPI staining (left panel) and by measuring caspase 3/7 activation (DEVDase activity; right panel). (B) HuH-7 cells were transiently transfected with plasmids encoding HA-PACS-2 or S-PACS-2 or with an empty plasmid (pcDNA3.1) as control for 48 hours, then treated with TRAIL (10 ng/ml) ± JP1584 (500 nM) for 6 hr. Apoptosis was assessed morphologically after DAPI staining (left panel) and by measuring caspase 3/7 activation (right panel). DEVDase activity is expressed as fold increase of relative fluorescent units over control value (untreated). *p<0.01. (C) Primary mouse hepatocytes from wild-type (WT), <i>Pacs-2</i>^−/−, <i>cIap1</i>^−/− or <i>cIap2</i>^−/− KO mice were treated with TRAIL (25 ng/ml) ± JP1584 for 8 hr. Apoptosis was assessed morphologically after DAPI staining. *p<0.001; **p<0.01, ns = non significant.