Objective To detect the osteogenic characteristic of marrow Flk1+mesenchymal stem cells(Flk1+MSCs) of multiple myeloma (MM) patients, and to investigate its relationship with MM.Methods Real-time RT-PCR was employed to test osteogenic markers and a 14-3-3? binding protein,TAZ(transcriptranscriptional coacti-vator with PDZ-binding motif) expressions of Flk1+MSCs of MM before and after osteogenic differentiation, andvon Kossa staining was performed to evaluate the mineral deposition after osteogenic differentiation.Results Osteo-genic markers andTAZexpressions in Flk1+MSCs of MM decreased significantly as compared to healthy donors,and mineral deposition was decreased in MMgroup(P0.05).Conclusion Osteogenic potential of marrowFlk1+MSCs of myeloma patients is decreased and the abnormalTAZexpression may play a role in this pathology process.

The level of TGF-#beta#1 was evaluated by enzyme linked immunosorbant assay (ELISA); after the TGF-#beta#1 was neutralized by its correspondig mAb, the ability of T lymphocyte-proliferation was measured by ~(3)H-Thydimine incorporation; and the level of interferon-gamma (IFN-#gamma#) was measured by Eli-spot kit. MSCs reduced the level of IFN-#gamma# secreted by activated T lymphocytes; inhibited the ability of T-lymphocyte proliferation and such an effect could be reversed partly by anti-TGF-#beta#1 antibody. MSCs inhibit T-lymphocyte proliferation through secreting TGF-#beta#1.