Fig. 2

Human multiple myeloma ANBL-6 cells rapidly reduce MAR upon exposure to proteasome inhibition. a MAR vs. mass plot for bortezomib-sensitive (ANBL-6.WT) and bortezomib-resistant (ANBL-6.BR) cells exposed to 5 nM bortezomib (bort) with 1, 3, and 5 h-long treatment duration. b Same data as in a shown as MAR per mass box plot. Boxes represent the inter-quartile range and white squares are the average of all MAR measurements. Welch’s t-test has been used to calculate p values, comparing treatment groups to 0-h control. ****p < 10⁻⁴ in highlighted segments. All treatment groups for the ANBL-6.WT cells have p < 10⁻⁵, where for the bortezomib exposure from 1 to 5 h; p(control vs. 1-h. bort.) = 4.8 × 10⁻⁵, p(control vs. 3-h. bort.) = 5.3 × 10⁻¹⁶, and p(control vs. 5-h. bort.) = 4.7 × 10⁻²⁶. From left to right, number of cells in MAR measurements; n(ANBL-6.WT) = 53, 43, 62, 47 and n(ANBL-6.BR) = 59, 72, 62, 57. c Cell viability by trypan blue showing the increase in the cell death for ANBL-6.WT upon exposure to bortezomib, while ANBL-6.BR cells are unaffected. Error bars represent three times the standard deviation with n = 3 for each condition. d Representative MAR vs. mass plot with overlay of an orthogonal vector (black dotted line), which designates the threshold resulting from LDA. e ROC curves of control (t = 0 h) and treatment (bortezomib) group for ANBL-6.WT and ANBL-6.BR cells at different treatment duration (t = 1, 3, 5 h). Cells, which are sensitive and resistant to drug therapy, are shown with blue and red lines, respectively. f MAR per mass plot for ANBL-6.WT cells exposed to different bortezomib concentrations, between 0.5 and 20 nM under 5 h-long treatment, showing the further reduction for larger bortezomib concentration. Figure inset shows the calculated AUC values for each bortezomib concentration, where AUC converges to 1 with increasing bortezomib concentration. Number of cells in MAR measurements from left to right; n = 53, 65, 58, 70, 61, 47, 52, 49, and 68