Fig. 7

The TL/Btz regimen is active against primary CD138⁺ MM cells and diminishes primitive progenitor cell-enriched CD138⁻/CD19⁺/CD20⁺/CD27⁺ populations while sparing normal CD34⁺ cells. a Representative primary bone marrow cells from a patient with MM (RR, relapse and refractory; prior Btz) were exposed to 500 nM TL +/− 3 nM Btz for 24 h, after which the cells were stained with CD138-PE and annexin V-FITC. Images were obtained with an IX71-Olympus inverted system microscope at × 200 magnification. Flow cytometric analysis was performed to determine the CD138⁺ population. b After exposure to 500 nM TL +/− 3 nM Btz for 24 h, the percentage of primitive CD138⁻/CD19⁺/CD20⁺/CD27⁺ cells in bone marrow mononuclear cells from a primary MM sample was determined by multi-color FCM. c Primary cells from a patient with newly diagnosed MM were exposed to 500 nM TL +/−  3 nM Btz for 24 h in the presence of HS-5, after which they were stained with CD138-PE and annexin V-FITC. Images were captured with an IX71-Olympus inverted system microscope at × 200 magnification. d Parallel experiments were carried out with 43 primary samples. Viability of CD138⁺ cells was analyzed by multi-color flow cytometry determination of 7-AAD. Lines indicate means and SD (****P < 0.001). e After exposure to 500 nM TL +/− 3 nM Btz for 24 h, apoptosis of CD138⁻/CD19⁺/CD20⁺/CD27⁺ cells (n = 31) was analyzed by 7-AAD staining and quantitated by multi-color flow cytometry (****P < 0.001). f Parallel experiments were carried out with eight primary cord blood (CB) CD34⁺ samples. ns, not significant