Fig 1: Combination studies of KS151 with bortezomib. (A-B), Annexin V staining to detect either MM.1R or RPMI 8226 apoptotic cells. MM.1R or RPMI 8226 cells were treated with 5 µM of KS151 alone or in combination with 20 nM bortezomib. After 24h, cells were stained with Annexin V dye and analyzed by the Muse Cell Analyzer by a method described in the materials and methods section. (C-D), Annexin V staining to detect CD138 - MM.1R and CD138 - RPMI 8226 apoptotic cells. After sorting CD138 - cells from MM.1R or RPMI 8226 with Bio-Rad cell sorter, cells were kept in the incubator overnight to recover and then treated with 5 µM of KS151 alone or in combination with 20 nM bortezomib. After 24 h, cells were stained with Annexin V dye and analyzed by Muse Cell Analyzer. (E-F), Annexin V staining to detect CD19+CD27+CD 38 - MM.1R and CD19+CD138 - apoptotic cells. After sorting CD19+CD27+CD38 - or CD19+CD138 - cells from MM.R with Bio-Rad cell sorter, cells were kept in the incubator overnight to recover and then treated with 5 µM of KS151 alone or in combination with 20 nM bortezomib. After 24h, cells were stained with Annexin V dye and analyzed by Muse Cell Analyze. One-way ANOVA was used to determine statistical significance. Each data point is the average of three replicates. *p = 0.05, **p = 0.04, ***p = 0.0001, ****p = 0.0001 significant.