Fig. 3.

Production of IL-6 in cultures and co-cultures of BMSCs of MM patients and control subjects with RPMI8226 myeloma cells. Production of IL-6 was measured by ELISA (A) and by cytometric analysis in monocultures of CD166⁺ cells (markers for mesenchymal stromal fibroblasts), monocultures of CD38⁺/CD138⁺ myeloma cells, and in co-cultures where both types of cells were in direct cell-to-cell contact (direct) or were separated by a transwell (non-contact). The level of IL-6 expression was measured by flow cytometry as the percentage of IL-6-expressing cells (C, D) or as the MFI (E, F), indicating the level of IL-6 expression in cells. Moreover, production of sIL-6R was measured by ELISA (B). *Significantly different from the control group, p<0.05; #significantly different from monoculture within the group, p<0.05.