Abstract:

Objective   To investigate expression levels of transforming growth factor-β1 (TGF-β1) and hepatocyte growth factor (HGF) in mesenchymal stem cells (MSC) of myelodysplastic syndrome-refractory anemia (MDS-RA) and myelodysplastic syndrome-refractory anemia with excess blasts (MDS-RAEB), and to discuss the immunosuppressive effects of MSC in the pathogenesis of MDS.  Methods   Bone marrow samples were collected from patients with MDS at diagnosis (n=23, 14 from MDS-RA, 9 from MDS-RAEB) and 12 controls. MSCs from bone marrow samples were isolated, cultured and expanded. The morphology of MSCs of the three groups was compared. The transforming growth factor-β1 and hepatocyte growth factor mRNA expression levels were detected by RT-PCR, the TGF-β1 and HGF concentrations of MSCs were tested by enzyme-linked immunosorbent assay (ELISA).  Results   The cultured cells from the patients with MDS presented a typical fibroblast-like morphology, which had no significant change compared with that of the controls. TGF-β1 and HGF mRNA expression levels and the TGF-β1 and HGF concentration levels in the MSCs of MDS-RA and MDS-RAEB groups were significantly lower than those of the control group(P<0.05). TGF-β1 and HGF mRNA expression levels and TGF-β1 and HGF concentration levels in the MSCs had no significant difference between the MDS-RA and MDS-RAEB groups (P>0.05). Conclusions   TGF-β1 and HGF mRNA expression levels and TGF-β1 and HGF concentration levels in the MSCs of MDS-RA and MDSRAEB groups weresignificantly lower than those of the control group, resulting in the decreasing ability of MSC immune suppression. Its mechanism may be related to lower immune surveillance and abnormal monoclonal hematopoiesis.

Key words: myelodysplastic syndrome; mesenchymal stem cells; transforming growth factor-β1; hepatocyte growth factor