Culture and regulation of osteoblasts in multiple myeloma patients

Abstract

To investigate the biological characteristics of osteoblasts cultured in vitro from bone marrow (BM) of multiple myeloma (MM) patients and to explore their generation and osteogenic potential. Effects of some factors such as bortezomib and MM patient serum on the osteoblasts were observed. Twenty MM patients and 10 healthy donors as controls were enrolled in this study. Osteoblasts from MM patients'BM were cultured in vitro. The generation and osteogenic potential of osteoblasts from MM patients and normal subjects were compared. The changes of their osteogenic potential and biological characteristics were observed. The antigens (CD34,CD138,CD45) on osteoblasts were catalyzed by flow cytometry. The levels of IL-7 were measured by ELISA. The BMP2 mRNAs were measured by RT-PCR. Osteoblasts from MM patients'BM could be cultured in vitro. The quantity of osteoblasts from MM patients (6.3±1.5) was less than normal subjects (8.2±2.6) (P<0.05). The osteoblasts cultured with MM patient serum (7.4±1.1) were less than those without patient serum (8.2±2.6) (P<0.05). Bortezomib increased those from MM patients after 6 days culture (8.9±2.1 vs 6.3±1.5) (P<0.05). Von Kossa staining showed that there were more calcium depositions in MM osteoblasts with bortezomib (8.8±1.9) than those without bortezomib (6.1±1.6) (P<0.05), but less than those from normal controls (15.8±2.2) (P<0.05). CD138, CD45, CD34 were not detected on the cultured cells. The level of IL-7 in MM patients'serum (2.07±0.71) was higher than that in normal controls (1.62±0.15) (P<0.05). The expression of BMP2 mRNA was seen in the normal osteoblasts and MM patients'osteoblasts cultured with bortezomib, but not be seen in those without bortezomib. Osteoblasts could be cultured in vitro from MM patients' BM. The proliferation and osteogenic potential of osteoblasts from MM patients were decreased. Bortezomib was a positive regulatory of osteoblasts and MM patient serum was a negative one. They both could affect the proliferation and osteogenic potential of osteoblasts.