Fig. 3. Cdc37 is gradually upregulated during plasma cell maturation and positively correlates with Xbp1s.

a Bone marrow MM cells were enriched by sequential FACS of lymphoid FSC/SSC, negative selection for CD2 (T and NK cells) and CD14 (monocytes), as well as gated into a subpopulation by CD38 and CD138 status. b Sorted CD38⁻CD138⁻ pre-plasmablast, CD38⁺CD138⁻ plasmablast, and CD38⁺CD138⁺ plasma cells were subjected to qRT-PCR analysis for gene expression of Cdc37 and Xbp1s. c CD38⁻CD138⁻ pre-plasmablast, CD38⁺CD138⁻ plasmablast, and CD38⁺CD138⁺ plasma cells were subjected to immunofluorescence analysis for protein expression of Cdc37 and Xbp1s. d Immunofluorescence analysis of Cdc37 and Xbp1s in CD138⁺ cells derived from a newly diagnosed patient responding to BTZ-based treatment (MM patient 1) and a patient displaying resistance to BTZ (MM patient 2). e Correlation analysis of gene expression of Cdc37 and Xbp1s from 45 newly diagnosed and 18 relapsed MM patients from qRT-PCR data. f Data obtained from GSE2658 showing prognostic relevance of Xbp1s mRNA on MM. Kaplan–Meier analyses revealed that MM patients with low expression of Xbp1s had inferior event-free survival in newly diagnosed TT2 and TT3 cohorts.