Objective: To study the effects of HDACi on the expression of survivin and NF-kappaB in human myeloma cell line U266 cells.
Methods: U266 cells were cultured in RPMI 1640 in the presence of MS-275, and the cell viability was evaluated by trypan blue exclusion assay and cell count. The cell morphological changes were observed with Wright-Giemsa staining. The cell cycle was analyzed by flow cytometry, and the proteins of poly (ADP-ribose) polymerase (PARP), caspase-3, survivin, p21, CDK4 and IkappaB-alpha were detected by Western blotting.
Results: MS-275 inhibited the growth of U266 cells in a dose- and time-dependent manner. The cell cycle was arrested at G(0)/G(1) phase. After exposure at 1.39 micromol/L MS-275 for 48 hours, the cell viability was decreased to 50%. The cell ratios of G(0)/G(1) phase were increased to (64.57 +/- 4.09)% for 24 h and (87.20 +/- 2.83)% for 36 h after 2 micromol/L MS-275 treatment. The visible morphological changes of U266 cells were confirmed with Wright-Giemsa staining. Cleaved-PARP, increased expression of p21, downregulation of expression of survivin, CDK4 and the phosphorylation of IkappaB-alpha was found by Western blot in MS-275 treated U266 cells.
Conclusion: MS-275-induced apoptosis of U266 cells is mediated by downregulation of expression of survivin and inactivation of NF-kappaB survival signalling pathways.