Western blot analysis

1.5 × 10⁶ cells were seeded in 6-well plates and treated with DEX and selinexor alone and in combination. The cells were then washed with 1X PBS and lysed with RIPA buffer (#89901, Thermo Scientific) supplemented with protease inhibitors (#05892791001, Roche) and phosphatase inhibitors (#04906837001, Roche). Protein levels were determined and normalized using Pierce’s BCA assay (#23225, Thermo Scientific). 20 μg of each sample were run in 4–12% Bis-Tris Gel (Life Technologies) and later transferred to nitrocellulose membrane using iBlot Gel Transfer Kit (Life Technologies). The membranes were blocked using LI-COR blocking buffer (#927-40000, LI-COR), probed with the indicated antibodies and analyzed using Licor Odyssey. Densitometry values were obtained using Image J software [72].