Increased Number of Mesenchymal Stem Cell-like Cells in Peripheral Blood of Patients with Bone Sarcomas

Background and Aims The number of peripheral blood mesenchymal stem cells (PBMSCs) may increase under pathological conditions. We sought to compare the number of MSC-like cells in the peripheral blood of patients with bone sarcomas with healthy controls and to analyze related cytokines in the peripheral blood plasma. Methods Peripheral blood mononuclear cells (PBMNs) of patients with bone sarcomas and control subjects were isolated for culture and analyzed by flow cytometry for MSC phenotype. Cytokines in the plasma obtained after cell separation were analyzed using enzyme-linked immunosorbent assay (ELISA). Annexin-V and β -galactosidase staining were used to investigate whether the cells died from apoptosis or senescence. Results Flow cytometric analysis demonstrated an >9-fold increase in the number of cells with MSC-like phenotypes (CD34– , CD45– , CD105+ ) in patients with bone sarcomas compared with control subjects ( p