Combination of NFκB and PI3-kinase/AKT inhibitors induce synergistic inhibition of cell viability and induction of apoptosis in PEL cell lines.

(A) Combination of sub-toxic doses of Bay11-7085 and LY294002 suppresses growth of PEL cells. BC1 and BC3 cells were treated with either 1 µM Bay11-7085 or 5 µM LY294002 alone or in combination for 24 hours. Cell viability was measured by MTT assays as described in Materials and Methods. The graph displays the mean +/− SD (standard deviation) of three independent experiments, * p<0.05, statistically significant (Students t-test). (B and C) Combination of Bay11-7085 and LY294002 induces efficient apoptosis in PEL cells. BC1 and BC3 cells were treated with either 1 µM Bay11-7085 or 5 µM LY294002 alone or in combination for 24 hours. Following treatment, cells were stained with FITC conjugated annexin V/PI and cells were analyzed by flow cytometry as described in material and methods (B). Bar graph denotes percentage apoptosis of three independent experiments (C). (D) Combination of sub-toxic doses of Bay11-7085 and LY294002 induced apoptosis is caspase dependent. BC1 cells were treated with either 1 µM Bay11-7085 or 5 µM LY294002 alone or in combination for 24 hours. Following treatment, cells were lysed and equal amounts of proteins were separated by SDS-PAGE, transferred to PVDF membrane, and immunoblotted with antibodies against caspase-9, caspase-3, cleaved caspase-3 and PARP. Beta-actin was used for equal loading.