Objective: To study the protective role of amifostine (WR-2721) in the mesenchymal stem cells (MSC) derived from non-Hodgkin lymphoma (NHL) bone marrow treated with etoposide (VP-16).
Methods: MSC were obtained from non-Hodgkin lymphoma bone marrow, cultured in expanded medium, and then divided into 4 groups: Group A, without treatment by either WR-2721 or VP-16 and used as control group, Group B, treated with WR-2721, Group C, treated with WR-2721 + VP-16, and Group D, treated with VP-16 alone. Inverted microscopy was used to observe the growth of the MSC. Flow cytometry was used to observe the apoptosis and immunophenotypes of the MSC. Mononuclear growth and apoptosis of the MSC Mononuclear bone marrow cells were obtained from 5 healthy volunteers and added into the MSC of the 4 groups, 4 weeks later methylcellulose progenitor assay and then inverted microscopy were used to measure the numbers of colony so as to detect the hematopoiesis. MSC of different groups were put into osteocyte-inducing and adipocyte-inducing media respectively, and 2 weeks later Von Kossa staining and oil-red O staining were used to identify the differentiation into bone and fat.
Results: The NHL derived MSC of the 4 groups all showed a typical fibroblast-like morphology and were all positive in CD29, CD44, and CD105, while negative in CD11b, CD31, CD34, CD45, and HLA-DR. The apoptotic rate of Group D was 31.2% +/- 4.3%, significantly higher than those of the other 3 groups (all P < 0.05), and the apoptotic rate of Group C was significantly higher than those of Groups A and B (both P < 0.05), however, still significantly lower than that of Group D (P < 0.05). The ability to support hematopoiesis of Group B was not significantly different from that of Group A, and Groups C and D showed a lower ability to support hematopoiesis in comparison with Groups A and B, However, the ability of Group C was still significantly higher than that of Group D (P < 0.05). Under suitable conditions, all the MSC differentiated into osteocytes or adipocytes.
Conclusion: Amifostine alone has no effects on proliferation, apoptosis, immunophenotype or ability of hematopoiesis support of the MSC in vitro; however, it can protect NHL patient-derived MSC from injury by VP-16 in vitro.