Anti-MM activity of b-AP15. (A) MM cell lines were treated with DMSO or b-AP15 at different concentrations for 48 hours, followed by measurement of cell viability with 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) assay. (B) Purified CD138⁺ patient MM cells were treated with DMSO or b-AP15 for 24 hours, followed by assessment of viability using CellTiter-Glo assay. (C) PBMCs from healthy donors were treated with DMSO or b-AP15 for 48 hours, and cell viability was measured by CellTiter-Glo assay. (D) MM.1S cells were cultured alone or with BMSCs for 48 hours in the presence or absence of b-AP15, and DNA synthesis was measured by ³H-TdR (tritiated thymidine) uptake. (E) MM.1S cells were pretreated with DMSO or b-AP15 overnight and then allowed to migrate for 4 hours in a transwell plate in the presence or absence of 10% serum or SDF-1. Migrating cells were detached and quantified by fluorescence (mean ± SD; n = 3; P < .001).