Figure 1.

Characterization of bortezomib-resistant MM cell lines, and primary relapsed MM patient samples. (A) The IC₅₀ Log[bortezomib] (nM) of bortezomib-naïve and bortezomib-resistant MM cell lines was analyzed by luminescent cell viability assay. (B) Relative cell viability (5 nM/48 h) and (C) chymotrypsin-like proteasome activity in bortezomib-naïve and bortezomib-resistant MM cell lines in response to (5 nM/4 h) bortezomib. (D) Relative cell viability of primary naïve and primary relapsed MM patient samples in response to bortezomib (5 nM/24 h). Statistical significance between treatments was calculated by Student's t test; * indicates P ≤ 0.05. Statistical significance between cohorts was calculated by ANOVA; # indicates P ≤ 0.05.