Effect of interleukin-6 (IL-6) on basic fibroblast growth factor (bFGF) secretion by myeloma cell lines.

Basic FGF concentrations in supernatants of U-266 (A) and RPMI-8226 (B) cells after exposure to 0 (control) or 10 ng/mL IL-6 for 72 hours in the absence or presence of polyclonal antihuman IL-6 antibody (1.5 μg/mL anti–IL-6). Basic FGF concentrations were corrected for 10⁶ cells and are presented as medians and interquartile ranges of 3 independent experiments. The Mann-Whitney rank sum test was used to identify differences between groups (U-266: control vs IL-6,P = .02; IL-6 vs anti–IL-6, P = .02; RPMI-8226: control vs IL-6, P =  .1; IL-6 vs anti–IL-6,P = .02).