Vitro Culture and Regulation Of Osteoblasts and Cellular Immunity Function In Multiple Myeloma patients

To investigate the biological characteristics of osteoblasts（OBs) cultured in vitro from bone marrow（BM) of multiple myeloma(MM) patients and to explore their generation and osteogenic potential. Then the affects by some factors such as bortezomib and MM patient serum on the OBs were observed. To explore the cellular immunity changes and the relationship between OBs and the immunity in MM.

OBs from BM of MM patients were cultured in vitro. The generation and osteogenic potential of OBs 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 OBs and the quantities of T cell subsets，Dendritic cells(DC)，effective T cells、regulatory T cells and helper T cells (Th）were examined with flow cytometry assay. And then correlation was analyzed between OBs and the immunity. The levels of IL-7 were measured with ELISA. The BMP2 mRNAs were measured by RT-PCR.

OBs from BM of MM patients could be cultured in vitro. The quantity of OBs from MM patients was less than normal subjects. There were calcium depositions in both groups after cultured for 4weeks culture. But the depositions of MM patients was less than that of normal controls. The OBs cultured with MM patient serum were less than those without patient serum. Bortezomib increased those from MM patients. CD138, CD45, CD34 were not detected on the cultured cells. The ratio of CD4+/CD8+、DC1/DC2、CD8+CD25+/CD3+T were reduced, that of helper T cell (Th1/Th2) was significantly decreased; the percentages of CD4+CD25+/ CD3+T and CD4+CD25+CD127low/CD4+T were significantly higher. Some of them were correlated with the quantity of OBs. The level of IL-7 in serum of MM patients was higher than that of normal controls. The expression of BMP2 mRNA was seen in the normal OBs and MM patients’ OBs culured with bortezomib, but not be seen in those without bortezomib.

OBs could be cultured in vitro from BM of MM patients. The proliferation and osteogenic potential of OBs from MM patients were decreased. Bortezomib was a positive regulatory of OBs and MM patient serum was a negative one. They both could affect the proliferation and osteogenic potential of OBs. There were down-regulations of quantity and function of T cell subgroup, DC cell, helper T cell, effector T cell while the regulatory T cells relatively raised. Predominantly of them were correlated with the quantity of OBs.

No relevant conflicts of interest to declare.