Effects of MM on expression of EFNB2 and EPHB4 in human bones in vivo and in cultured MSCs, osteoblasts, and osteoclast precursors. (A) Conditioned media from cultures of myeloma cell lines (U266 and CF) and primary myeloma plasma cells or control media were injected twice a day for 3 days into the surrounding area of the implanted human bone in nonmyelomatous SCID-hu mice (5 mice/conditioned media from each source). Note reduced expression of EPHB4 but not EFNB2 by myeloma cell-conditioned media. (B) Fetal human MSCs were cultured alone or cocultured with U266 and CF MM lines and primary myeloma cells for 3 days using transwell inserts22 and then subjected to quantitative RT-PCR analysis. Note reduced expression of EPHB4 in MSCs cocultured with all types of myeloma cells, whereas EFNB2 expression was reduced in coculture with U266 and CF cells but not primary myeloma cells. P values represent differences between cultured and cocultured MSCs. (C) Fetal osteoblasts (OB) similarly cocultured with primary myeloma plasma cells for 3 days had reduced EPHB4 expression as determined by quantitative RT-PCR analysis. (D) Osteoclast precursors (pOC) were cultured alone or cocultured with primary myeloma cells in osteoclastic media. After 3 days, myeloma cells were removed from cocultures and the pOC subjected to quantitative RT-PCR analysis. Myeloma cells had no effect on EFNB2 expression by pOC.
