Figure 5

Myeloma cells downregulate IGFBP7 in BMSCs. Co-culture of hBMSC TERT+ cells and MM cell lines (A) or primary MM cells (B) was performed in the presence or absence of transwell inserts for 72 hours. Human BMSC TERT+ monocultures served as control. Direct contact cultures were separated by MACS sorting previous to RNA isolation of the CD138-negative fraction. IGFBP7 mRNA levels were analysed by quantitative PCR and compared to the control. Values represent the mean ± SD of three independent experiments performed in triplicates for MM cell lines and mean ± SD of triplicate experiments for primary MM cells. (C) Downregulation of IGFBP7 in the myeloma microenvironment was confirmed by GEP analysis of whole bone marrow (WBM) samples obtained from healthy donors (ND) and newly diagnosed myeloma patients (MM). Asterisks indicate statistical significance compared with the control (* P < 0.05, ** P < 0.01, *** P < 0.001).