Figure 2.

Fil→Mel sequential treatment significantly inhibits drug-free recovery of human myeloma cell lines. U266, MM1S and NCIH929 cells were treated with melphalan (10 μM) for 1 h followed by filanesib (1.75 nM) for 48 h (Mel→Fil) or inversely with filanesib for 48 h followed by 1 h melphalan (Fil→Mel). At the end of treatment, cells were resuspended in drug-free media and allowed to recover for 7 days. (a) Apoptosis was assessed 48 h after drug washout by Annexin V staining (N=3). Statistical analysis was performed by Two-way ANOVA for each treatment protocol independently. (b) Cellular proliferation was assayed on day 3 and day 7 following drug washout. For direct comparison of Mel→Fil and Fil→Mel treatment protocols, the percent growth from the beginning of the experiment was compared using a two-tailed Student's t-test (N=3). Statistical significance was set at P<0.05.