Interleukin-6 (IL-6) and basic fibroblast growth factor (bFGF) in noncontact cocultures of purified marrow myeloma cells (MMCs) and stromal cells (BMSCs) from patients.
(A) Enhanced IL-6 secretion of BMSCs derived from myeloma patients in transwell cocultures with MMCs (P = .02 vs BMSC monocultures). The addition of anti-bFGF or anti-bFGF plus anti-VEGF antibody resulted in a significant reduction of IL-6 secretion (P = .02 and P = .02, respectively, vs native cocultures containing no antibody). IL-6 secretion by BMSCs and MMCs served as baseline controls. IL-6 concentrations were determined in serum-free supernatants of 72-hour culture. Results were corrected for 105 cells and are presented as medians and interquartile ranges of 5 independent experiments. Analysis of significance for group differences was performed by the Mann-Whitney rank sum test. (B) Increased bFGF secretion into supernatants of noncontact cocultures of MMCs with BMSCs (P = .03 vs MMC monocultures). The addition of polyclonal antihuman IL-6 antibody (5 μg/mL) revealed no significant effect. Basic FGF concentrations were determined in supernatants of serum-free 72-hour cultures and corrected for 106 cells. MMC and BMSC monocultures served as baseline controls. Data are presented as medians and interquartile ranges of 4 independent experiments. Analysis of significance for group differences was performed by the Mann-Whitney rank sum test.
