(A) Dexamethasone-sensitive (MM.1S) and -resistant (MM.1R) human myeloma cells were exposed (24 h) to 1 nM FK228 ± 2 nM Btzmb, after which the percentage of Annexin V+ (apoptotic) cells were determined by flow cytometry. (B) Btzmb-resistant cells (U266/PS-R) were generated by culturing U266 cells in gradually increasing concentrations of Btzmb up to 12 nM. U266/PS-R cells were treated for 48 h with 2 nM FK228 in the absence or presence of 5–15 nM Btzmb, after which apoptosis was assessed by Annexin V-FITC staining and flow cytometry.
Btzmb: Bortezomib; Ctrl: Control; FK228: Romidepsin.
[Grant S, Dai Y, Unpublished data].