Supernatant fluids from the cultures of bone marrow cells from 10 of 12 patients with multiple myeloma (MM) caused bone resorption in organ cultures of fetal rat calvaria. In four patients, the marrow cells were cultured with and without indomethacin (1 μM). The supernatant fluids from indomethacintreated marrow cultures caused significantly less bone resorption than supernatant fluids of cell cultures without indomethacin. This inhibition of release of bone resorbing factor(s) by myeloma cultures is similar to the previously observed indomethacin-induced inhibition of osteoclast-activating factor (OAF) production by activated human leukocytes. None of the MM supernatants had any effect on cyclic (c)AMP accumulation in resorbing bone in vitro.
Robert G. Josse, Timothy M. Murray, Gregory R. Mundy, Donna Jez, Johan N. M. Heersche