Fig. 1: Low expression of Cdc37 is linked to BTZ resistance in multiple myeloma.

a Heatmap showing Cdc37 mRNA expression in a sequential MM sample set [at diagnosis (Baseline), pre first transplantation (Pre T1), pre second transplantation (Pre T2), and post second transplantation (Post T2)], data obtained from GSE19554. b Cdc37 mRNA expression was detected in CD138⁺ cells from 60 newly diagnosed MM patients (ND) and 25 relapsed cases (Relapsed). The relative Cdc37 mRNA expression in ND and relapsed MM patients was 0.78 ± 1.13 and 0.25 ± 1.07, respectively (*p < 0.05). c Cdc37 protein expression in primary MM cells was examined with ICC. Left panel: MM cells derived from 14 newly diagnosed patients (ND) and 10 relapsed patients (Relapsed) were subjected to ICC for Cdc37 protein expression, and representative cases are shown. Right panel: The semiquantitative scoring is shown. The relative Cdc37 protein expression in ND and relapsed MM patients was 1.90 ± 0.85 and 0.81 ± 0.44, respectively (**p < 0.01). d Cdc37 mRNA expression (upper) and protein level (lower) were examined in ANBL6.WT/ANBL6.BR cells (left), RPMI-8226/RPMI-8226.Dox40 cells (middle), and MM.1S/MM.1R cells (right) by qRT-PCR and western blot. e Cdc37 mRNA expression was detected in CD138⁺ cells from 14 patients relapsed after BTZ-based treatment, while 11 cases relapsed after other therapy without BTZ. The relative Cdc37 mRNA expression was −0.21 ± 1.05 and 0.83 ± 0.83, respectively (*p < 0.05).