Figure 5

Apoptosis induction and accumulation of ubiquitinated proteins in bortezomib-resistant 8226 (MM), THP1 (AML) and CEM (ALL) cells after sensitizing cells for bortezomib with IFN-γ. Western blot analysis of PARP cleavage and expression of NOXA as indicators of apoptosis and accumulation of polyubiquitinated proteins in untreated cells, after 24 h exposure to bortezomib (100 nM for 8226/BTZ100 and 200 nM for both CEM/BTZ200 and THP1/BTZ200), single IFN-γ (100 U/ml), or the combination of IFN-γ and bortezomib.